ANNUAL REPORT 2006 - Forschungszentrum L3S

ANNUAL REPORT 2006

In today‘s society, individuals and organizations are, on one
hand, confronted with an ever growing load of information and
content and, on the other, with increasing demands for knowledge
and skills. To cope with this, we need to link content, knowledge and
learning, making content and knowledge more accessible, interactive
and usable over time by humans and machines alike.
This is how „Challenge 4: Digital Libraries and Content“, one of
seven challenges focusing ICT research and technological development
in Europe which is funded through the Seventh Framework Programme
(FP7) is introduced. The paragraph equally well describes L3S
research initiatives and projects through which we investigate and develop
innovative methods and technologies focusing on knowledge,
information and learning as key enablers of the European Information
Society and Europe’s economical growth.
PROJECTS PREFACE
Knowledge, Information and Learning
as Key Enablers of the European Information Society
Third party funding through the EU/IST program amounts for about one third of our yearly budget of more
than 5 Million Euro; another third coming from German funding agencies and from industry. L3S thus plays a very
active role in European research, advancing the state of the art on all aspects concerned with digital resources and
their technological underpinnings (semantic web, digital libraries, distributed systems, networks and grids), as well
as the use of these resources in eLearning and eScience contexts.
One of these projects is the new Integrated Project PHAROS, which is funded by the European Union from
2007 to 2009. PHAROS aims at building a next generation audiovisual search platform, to be designed, developed
and applied jointly by a consortium consisting of 13 high-profile academic and industrial partners, including the
leading European search engine company FAST Search and Transfer, France Telekom, the Italian system integrator
Engineering, and the L3S Research Center. L3S contributions, funded with about 1 Mill. Euro, will focus on user
and context technologies, and will include innovative algorithms supporting user centric searching and robustness
against spam. L3S innovations will also build upon social network and blog analysis (important aspects in new Web
2.0 environments), which provide rich information about user preferences, and enhance user experience with the
PHAROS audio visual search platform.
This annual report provides a good opportunity to learn about this and many other projects, and contains descriptions
of exciting research results as well as interesting case studies and applications, developed in the context
of these projects. We hope you will find them as exciting as we do, and encourage you to contact our project leaders
and researchers for more details and cooperation possibilities.
L3S success builds upon the high motivation, enthusiasm, solid research background and competencies of all
members, researchers and staff. More than 70 researchers on Ph.D. and PostDoc positions, with 15 different nationalities,
provide an invigorating environment, which guarantees convincing results and successful work in all our
projects. This is what makes work at our institute so exciting for all of us, and L3S the right place to turn to for both
advanced research and innovative ICT solutions.
Hannover, February 2007
Prof. Dr. Wolfgang Nejdl, L3S Executive Director
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PROJECTS TABLE OF CONTENTS
Preface ........................................................................................................................3
Table of Contents ....................................................................................................... 4
ABOUT L3S
L3S Research Center in Profi le ............................................................................ 9 - 10
L3S Members ............................................................................................................ 11
Advisory Board ......................................................................................................... 11
L3S Staff ................................................................................................................... 12
New Projects
BRICKS ...................................................................................................................... 16
LINSearch ................................................................................................................. 17
PHAROS .................................................................................................................... 18
ACHIEVEMENTS AND RESULTS
TECHNOLOGY ENHANCED LEARNING
- COOPER ................................................................................................................. 22
- ELAN ...................................................................................................................... 24
- EVITA ..................................................................................................................... 26
- HELCA ................................................................................................................... 28
- L3SCPD .................................................................................................................. 30
- mstbildung ............................................................................................................ 32
- PROLEARN ............................................................................................................. 34
- PROLIX .................................................................................................................. 36
- TENCompetence ................................................................................................... 38
SEMANTIC WEB AND DIGITAL LIBRARIES
- APIS ....................................................................................................................... 40
- PUMA .................................................................................................................... 42
- P2P-IS .................................................................................................................... 44
- ELEONET ............................................................................................................... 46
- NEPOMUK ............................................................................................................. 48
- REWERSE ............................................................................................................... 50
- VIKEF ..................................................................................................................... 52
- PSW ....................................................................................................................... 54
- KnowledgeWeb ..................................................................................................... 56
- iSearch ................................................................................................................... 58
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DISTRIBUTED SYSTEMS AND NETWORKS
TABLE OF CONTENTS PROJECTS
- PeerTrust ............................................................................................................... 60
- D-Grid ................................................................................................................... 62
- PULSERS ................................................................................................................ 64
- UKOLOS ................................................................................................................ 66
- AFT ........................................................................................................................ 68
- Trobot ................................................................................................................... 70
- KIOP ...................................................................................................................... 72
NEWS AND EVENTS
L3S RESEARCH CENTER AT CEBIT 2007
Beagle++ Desktop Search
WebRatio® Competence Center Germany
Knowledge-based Hotline Support System
ELEONET: The Search Portal for Learning Objects
Federated Search .............................................................................................. 76 - 77
L3S supports international violin contest
L3S Researchers Win Best Student Paper Award .................................................... 78
EC-TEL 2006 – Conference series successfully started
IBM recognizes L3S Ph.D. student as one of Europe’s best .................................... 79
Best Student Paper Award at WWW2006
Stud.IP Developer workshop ................................................................................... 80
European Projects Join Forces in Professional Learning ........................................ 81
WORK AND COLLABORATION
International & Industrial Partners ................................................................. 84 - 85
Publications ...................................................................................................... 86 - 90
Programm Committee Memberships .............................................................. 91 - 94
Imprint .................................................................................................................... 96
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PROJECTS ABOUT L3S
integration appletree computer science just ru
exist learning toast with jam information cro
tomato sauce is red semantic web nail polish kn
green fun members space ship boiled egg dev
downtown research strong wind security talking
6
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+++ The L3S Research Center focuses on innovative
methods and technologies for three key research
fields of the European Information Society, namely
knowledge, information and learning. L3S is a
nationally and internationally renowned research
institute in these fields and especially in its core
areas of Technology Enhanced Learning, Semantic Web
and Digital Libraries +++
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
ABOUT L3S
nning around research blue bananas do not
codile investigation showercap digital libraries
owledge cloudy day in the fields tomcat content
elopment rain in salt lake city future walking
loudly policies eat garlic bread powerful teams
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L3S RESEARCH CENTER IN PROFILE
L3S Research Center in Profile
The L3S Research Center focuses on innovative
methods and technologies for three key research fields
of the European Information Society, namely Knowledge,
Information and Learning. In the last six years
L3S has successfully established itself as a nationally
and internationally renowned research institute in
these fields and especially in its core areas of Technology
Enhanced Learning and Semantic Web/Digital Libraries.
Today, more than 70 researchers work at the L3S
in the areas:
- Technology Enhanced Learning
- Semantic Web and Digital Libraries
- Distributed Systems and Networks
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L3S is the only research institution in Lower Saxony
to coordinate one of the prestigious Networks of
Excellence within the 6th Research Framework Program:
PROLEARN. Furthermore, L3S coordinates the
EU/IST COOPER Project and participates in two other
EU/IST Integrated Projects in the area of Technology
Enhanced Learning, PROLIX and TENCompetence. The
new PRO-LC Cluster integrates these and other EU/ IST
projects investigating innovative solutions for technology
enhanced learning, knowledge management and
business processes.
Semantic Web Reasoning, Metadata Management,
Trust and Security Policies and Personalization
are investigated in two EU/IST Networks of Excellence,
KnowledgeWeb and REWERSE. Edutella, iSearch and
NEPOMUK, an EU/IST IP started in 2006, focus on distributed
search and information retrieval, the use of
semantic and metadata information on the desktop,
and on sophisticated ranking algorithms for personalized
information retrieval, task specific access to
information, and spam detection and avoidance. The
NEPOMUK Social Semantic Desktop integrates many of
these aspects and will allow personalized and extremely
precise search on personal desktops and connected
repositories to work groups and other social networks.
In 2007 L3S starts PHAROS, an EU/IST IP focussing on
audio visual search infrastructures, aimed at achieving
extreme search precision through the analysis and exploitation
of user and community preferences.
Distributed Infrastructures are also very important
for the sharing of computing and information resources.
The BMBF project D-Grid started in fall 2005 and
aims to build a sustainable Grid-Computing-infrastructure
for education and research (eScience) in Germany.
New wireless transmission technologies are being investigated
as well. UltraWideBand (UWB) is a method
for a new type of short range radio communication including
location capabilities, which enables new learning
and collaboration scenarios, as well as ubiquitious
computing environments.

We focus on UWB media access control and location
methods in a subproject within the EU project
PULSERS II and a project within the DFG Priority Program
UKOLOS.
L3S success is largely attributable to international
alliances between some of the world’s most prominent
researchers and developers in L3S’s areas of focus and
to the international visibility of L3S members and staff;
L3S as a research institution is a very attractive place
for international students, two thirds of L3S employees
(Ph.D. students and PostDocs) come from abroad. The
number of researchers at L3S has increased substantially
in 2006, which underlines the importance of L3S as
an excellent place for Ph.D. and PostDoc researchers.
Work and resources have been very thoughtfully
and strategically invested in promising research fields
during the previous years. L3S managed to grow continuously
over the years and this trend will continue.
Over the last few years L3S has consistently and very
successfully increased funding from third parties. In
2006, L3S has succeeded in reaching an impressive percentage
of 65% third party funding, for 2007 this figure
will surpass 70%.
Given all these achievements, this report presents
L3S as a very visible pillar of Computer Science
and Information Technologies in Lower Saxony and as
an example for international, innovative and interdisciplinary
research combining the strengths of individual
professors, institutes and universities.
Hannover, February 2007
Dr. Uwe Thaden, L3S Managing Director
L3S RESEARCH CENTER IN PROFILE
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ORGANIZATION
Directors
Prof. Dr. techn. Wolfgang Nejdl Executive Director
Prof. Dr.-Ing. Gabriele von Voigt Deputy Director
Prof. Dr.-Ing. Ulrich Reimers Deputy Director
Dr. Uwe Thaden Managing Director
Dr. Christoph Strutz Managing Director
Members
Dr. Wolf-Tilo Balke Leibniz University Hannover
Prof. Dr.-Ing. Klaus Jobmann Leibniz University Hannover
Prof. Dr. techn. Wolfgang Nejdl Leibniz University Hannover
Prof. Dr.-Ing. Ulrich Reimers TU Braunschweig
Dir. Uwe Rosemann TIB / UB Hannover
Prof. Dr. Gerd Stumme University of Kassel
Prof. Dr.-Ing. Gabriele von Voigt Leibniz University Hannover / RRZN
Prof. Dr.-Ing. Bernardo Wagner Leibniz University Hannover
Associated Members
Prof. Dr. Michael Breitner Leibniz University Hannover
Prof. Dr.-Ing. Christian Grimm Leibniz University Hannover / RRZN
Prof. Dr. Nicola Henze Leibniz University Hannover
Prof. Dr. Herbert Matthies Hannover Medical School
Prof. Dr. Karl Neumann TU Braunschweig
Prof. Dr.-Ing. Stephan Olbrich Heinrich-Heine-Universität Duesseldorf
Prof. Dr. Lars Wolf TU Braunschweig
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Advisory Board
Prof. Marc Eisenstadt, Ph.D. Knowledge Media Institute / Open University UK
Prof. Dr. Matthias Jarke RWTH Aachen / Fraunhofer FIT / GI President
Prof. Dr. Hermann Maurer TU Graz / KNOW Center
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ADVISORY BOARD
Prof. Dr. Erich Neuhold ARC Seibersdorf Research GmbH, Research Studios Austria/
University of Vienna
Prof. Dr. Thomas Ottmann University of Freiburg
Prof. em. Dr. Dr. h.c. mult. A.-W. Scheer IDS Scheer AG
Prof. em. Gio Wiederhold, Ph.D. Computer Science Department, Stanford University, USA
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STAFF
Staff
M.Sc. Mohammad Alrifai
Dr. Wolf-Tilo Balke
Dipl.-Ök. Patrick Bartels
Dipl.-Wirtsch.-Ing. Kim Bartke
Kerstin Bischoff, M.A. IIM
Dr. Jan Brase
Dipl.-Ök. Finn Breuer
B.Sc. Marko Brosowski
Dipl.-Ing. Ingo Brunkhorst
Katia Cappelli
Ling Chen, PH. D.
M.Sc. Sergey Chernov
Dipl.-Ing. Paul-Alexandru Chirita
SungRan Cho, Ph.D.
Dipl.-Ing. Stefania Costache
Dipl.-Ing. Juri Luca De Coi
Dipl.-Inf. Gianluca Demartini
M.Sc. Dipl-Inf. (FH) Elena Demidova
Dipl.-Dok. FH Elena Derr
Dr. Jörg Diederich
Dr. Peter Dolog
Dipl.-Ing. Arnd Eden
Dr. Nils Faltin
Dipl.-Ing. Claudiu S. Firan
Dipl.-Päd. Uwe Frommann
Dipl. Ing. Stefan Galler
Dipl. Ing. Comm.-Sys. Julien Gaugaz
Dipl.-Inf. FH Gabriel Gaus
Dipl.-Ing. Rita Gavriloaie
M.Sc. Ralf Gröper
Dr. Nils Hagge
Dipl.-Ing. Andreas Heinrich
Dipl.-Ing. Mathias Hentschel
Dipl.-Ing. Inga Herbold
Dr. Eelco Herder
Dr. Thomas Huk
M.Sc. Ekaterini Ioannou
Dipl.-Ing. Tereza Iofciu
Dipl. Des. FH Anne-Kathrin Ittmann
Dipl.-Math. Robert Jäschke
Dipl.-Inf. Olaf Jansen-Olliges
M.Sc. Nils Jensen
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Dipl.-Inf. Philipp Kärger
Dipl.-Sozialwirt Cornelis Kater
Dipl.-Inf. Arne Wolf Kösling
Dipl.-Des. FH Dennis Kohlmetz
Dipl.-Inf. FH Christian Kohlschütter
Dipl.-Math. Beate Krause
M.Sc. Daniel Krause
Dipl.-Soz. Päd. FH Jörn Krückeberg
Dipl.-Berufspäd. Marc Krüger
Dipl.-Ing. Jörg Langenberg
Dipl.-Inf. Thomas Lösch
Dipl.-Inf. Christoph Lofi
Dipl.-Inf. Enrico Minack
Dr. Claudia Niederée
Dipl.-Inf. Stefan Ohlemeyer
Dipl.-Inf. Daniel Olmedilla
M.Sc. Odysseas Papapetrou
Dipl.-Ing. Maria Dolores Perez Guirao
Dipl-Ing. Golaleh Rahmatollahi
Dipl.-Ing. Marko Reimer
Dr. Claus-Peter Rückemann
Dipl.-Ing. Simon Frederik Rüsche
Claudia Saalbach
Dipl.-Phys. Robin Sandvoß
Dipl.-Math. Henning Schnoor
Dipl.-Wirtsch.-Ing. Henrik Schumacher
Dipl.-Ing. Harald Schwier
M.Sc. Joachim Selke
Dr. Wolf Siberski
Dipl.-Inf. Rodolfo Stecher
M.Sc. Avaré Stewart
Dr. Christoph Strutz
Dr. Uwe Thaden
M.Sc. Sascha Tönnies
Dipl.-Inf. Gian Luca Volpato
Dipl.-Päd. Ulrike von Holdt
Dipl.-Ing. Jan Wiebelitz
Dipl.-Inf. Andreas Wodrich
Dr. Martin Wolpers
Dipl.-Ing. Ana L. Zapater Alemany
Xuan Zhou, Ph. D.
Iris Zieseniß
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STAFF
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PROJECTS NEW PROJECTS
evaluation winning in the lottery search colourful fis
shower visual blue planet indexing peanut butter info
extraction receiving a love letter data never seen a yell
night metadata terrible hairstyle terms music in the a
+++ Over the years L3S has established itself as a
well renowned partner in national and international
research projects. Three new projects (PHAROS, BRICKS
and LINSearch) on digital library and search engine
infrastructures have started in January 2007 +++
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FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER

in the reef database duck chicken wings audio cold
rmation fly away development call your grandmother
ow hippo content cold feet in bed approach big city at
r document high noon scalability tennis socks control
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NEW PROJECTS
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NEW PROJECTS
BRICKS – Integrated Access to Distributed Cultural
Knowledge Resources
A large amount of digital content in the cultural domain will be accessible electronically. Libraries and
museums are providing large collections of multimedia documents to the public. Currently, cultural digital
information providers are highly distributed, which leads to an increasing user demand for integrated
access.
The BRICKS Project
The aim of the BRICKS project is to defi ne, develop and maintain
a user- and service-oriented space for sharing knowledge
and resources in the cultural domain. Users will have integrated
access to cultural knowledge, but they can also provide or
sell their own digital content to the public. With the help of
the BRICKS system, the provided content will be much more
visible for the interested audience. Retrieval of content will
be supported by a wide range of semantic and language oriented
services.
The Architecture
The development goal of the BRICKS architecture is to ensure
high reliability and availability while reducing administration
costs. The BRICKS infrastructure will be service oriented, decentralized
and self-organizing. Every cultural institution will
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
be able to freely join or leave the system with minimal administrative
effort. BRICKS users will still have the full control over
their own system and content. A security infrastructure will
ensure the integrity and rights of the digital content.
L3S Role in the Project
The role of L3S together with Fraunhofer IPSI in the project
is the development of a decentralized database for metadata,
which is similar to a distributed database but without a central
coordination point. It is therefore more reliable and higly
scalable. L3S and IPSI are also responsible for the development
of a general and fl exible annotation service, which can
be used by a wide range of application types. Both partners
coordinate the integration of German scientifi c and cultural
institutions.

The project
The aim of the LINSearch project is the development, evaluation
and usage of an integrated system for indexing and
searching technical and scientifi c documents for TIB and FIZ
Technik. This system should support the natural language of
the users as well as other languages, especially German and
English. To access documents the correct index terms about
a document are most important. Currently, indexing is done
manually by experts, which is very time-consuming. Also the
time-consuming, and the constantly increasing amount of publications
leads to reduced actuality of the provided information.
Approach
In the fi rst phase of the project available technologies for indexing
and information extraction will be used to automatically index
a subset of the documents of TIB and FIZ Technik. The results
will be evaluated and compared with the manually generated index.
In the next step, the different techniques will be combined
in order to exploit the benefi ts of different approaches.
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NEW PROJECTS
LINSearch – Indexing and Natural-language Search
for Technical and Scientific Documents
The daily business of TIB and FIZ Technik is to provide professional users with high quality information
in technical domains such as electrical and computer engineering or materials. For their users it is important
to get high quality results according to their queries delivered by intelligent retrieval technologies.
Semi-automatic indexing will support the experts in their job
by proposing appropriate index terms, which can afterwards
be corrected. With the help of self-learning algorithm index
algorithm should learn over time to improve its suggestions.
The user will be assisted during query formulation by the system
proposing related terms. After query execution, the result
set will contain not only the description of the documents,
but also related index terms, which can be used to further
refi ne the query. The retrieval engine, which handles the user
queries, combines linguistic methods and thesauri to improve
query results.
After three years
At the end of the project TIB and FIZ Technik will be able
to index new documents much more effi ciently and with a
higher quality. They will have strengthened their position in
the global information market, as their users always get high
quality and up to date information.
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NEW PROJECTS
PHAROS – Searching the Audiovisual Web
The PHAROS project is dedicated to the development of an integrated next generation search platform
for audio-visual search. PHAROS will develop a scalable search framework which lets users search, explore
and analyze contextually relevant data. In addition, PHAROS will create user interaction models
where live user traffi c contextually relevant improves the user experience via social network analysis and
spam-resistant ranking. An innovative showcase, built on the PHAROS platform, will be used to gather
user feedback and validate the PHAROS approach.
Search has been established as one of the main mechanisms
of dealing with the explosive growth in digital data. While
the web is commonly perceived as the largest corpus for
search, businesses and government organizations often have
much more data which needs to be systematically managed.
Further, newer data repositories containing multimedia data
along with text are growing at a fast rate and are expected
to drive new growth and new technologies for dealing with
audio visual search. The aim of PHAROS is to develop novel
technologies to deal with these scenarios.
Besides the requirements of accuracy and scalability, it is
expected that new technologies developed in PHAROS will
provide extensive support for user centric searching and robustness
against spam. Such techniques will ensure that next
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
generation search technology can deal with the huge heterogeneous
user population more accurately, while preventing
malicious companies and users from manipulating search results
using any form of spam. Further, PHAROS aims to harness
the large amount of information available within online
communities like MySpace and Orkut for better understanding
the requirements of search users. Social network and Blog
analysis is expected to provide rich information about millions
of user which can in turn be used to enhance their experience
with the PHAROS audio visual search platform.
L3S will serve as the scientifi c director of PHAROS. Within the
project, L3S will lead the research in ‘User and Context Technologies”,
working on Social Media, Advanced Personalization,
and Spam Detection.

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ACHIEVEMENTS & RESULTS
+++ L3S has continuously and successfully expanded
its range of projects and scientific results over the
last year while maintaining the focus of its objectives
and mission. It has clearly reached critical
mass and acknowledged leadership in its core research
fields. L3S is an influential research institute in
the German as well as in the international scientific
community and is a major player in international research.
L3S projects are connected to its three principal
research areas ‘Technology Enhanced Learning’,
‘Semantic Web and Digital Libraries’ and ‘Distributed
Systems and Networks’ +++
grey elephant security yellow efficient provider
growing slowly during winter technology bean s
husband microsystem technology desert coordinat
catching a cold integration dancing in the rain
web pullover with three holes information choc
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ACHIEVEMENTS & RESULTS
s sushi elearning butterfly knowledge grass is
oup with sausages academic lip gloss activities
ion rising high project pink hazelnut excellence
networks go for gold resources emotional motion
late is healthy digital libraries white wallpaper
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PROJECTS TECHNOLOGY ENHANCED LEARNING
COOPER – Collaborative Open Environment
for Project-centred Learning
Project-centred learning requires a dynamic working environment in which a group of people, with heterogeneous
backgrounds and competencies, can collaborate on a common project. Such an environment
helps learners to build various team-work, communication and problem solving skills. However, due to
geographical barriers, such an environment can hardly be established in most multinational companies
and universities. COOPER intends to defi ne and create an online project-centred learning environment
to support geographically dispersed learners.
Objective
The objective of COOPER is to create techniques and tools
that support team-based, project-centred learning in the following
circumstances:
• Graduate (or post-graduate) university studies involving
students and lecturers participating in focused projects (e.g.,
master or specialization courses) coming from different institutions
and backgrounds;
• Company universities and company training, involving
multi-national participants coming from a company’s site
or customers, which are dispersed world-wide, cooperating
to launch new products or technologies, or participating in
product- and project-centred training.
The research and development in COOPER is focused upon
the problem of: creating and managing virtual teams of persons
with heterogeneous backgrounds and competencies;
assessing their entry-level competencies and their scientifi c
growth; coordinating their collaboration as well as facilitating
their personalized growth; and even following them after
the end of their formal participation in the learning activities,
when they constitute an alumni community. This approach is
built upon project-centred learning and social network learning
situations, which is seen as an important mechanism for
breaking distance barriers and making effective use of eLearning
technology.
Approach
In the beginning of this project, extensive case studies were
conducted among several education and training institutions.
From these case studies, we generalize the following most important
technical requirements in the COOPER scenario.
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summary
COOPER is dedicated to develop and test a
model-driven, extensible environment that
supports individual and collective competency
building in virtual teams, whose members
are geographically dispersed, have different
backgrounds and competencies, and
are working together in projects to solve
complex problems.
• Defi ning a set of team management processes that are most
suitable for supporting project-centred learning in the COO-
PER scenario.
• Creating knowledge sharing and recommendation services
to facilitate collaborative teamwork processes.
• Defi ning pedagogical scenarios and assessment tools to
support competency building and competency assessment in
heterogeneous virtual project teams.
• Developing a web-based infrastructure with a set of telecommunication
tools to support the distant cooperation in a
distributed virtual team.
During the project, we exploit several technologies, including
collaborative learning, knowledge sharing, recommendation,
social network, process modeling, and synchronous communication.
All results delivered by the project will contribute to
forming a protected, shared COOPER platform that will be
easily deployed over any university or company intranet.

Impact
In the end, COOPER will contribute to:
• Defi ning innovative collaborative learning scenarios, which
focus on new ways of learner assessment, and contribute to
relevant standards;
• Supporting personalized and contextualized collaborative
learning situations by exploiting learner background, learner
interaction, and social networks in learning;
• Providing a model-driven, easy-to-use, and easy-to-reconfi
gure infrastructure, supporting learners in adapting to new
needs or requirements.
These contributions will facilitate more dynamic and realistic
learning scenarios, centred on the “learning by doing” approach.
The scenarios, approach, infrastructure, and methodology
will help institutes and universities to establish new
innovative project-centred study programmes in information
technology and related fi elds
TECHNOLOGY ENHANCED LEARNING PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
info box
Project Type: STREP
Duration: December 2005 – November 2007
Research Areas: Technology enhanced learning,
Web engineering, Information retrieval, Knowledge
sharing
Contact: Xuan Zhou, zhou@L3S.de
URL: http://www.cooper-project.org
selected publications
J. Diederich and T. Iofciu: Finding Communities of
Practice from User Profi les Based On Folksonomies,
1st International Workshop on Building Technology
Enhanced Learning solutions for Communities of
Practice (TEL-CoPs‘06), 2006, Greece.
Paul-Alexandru Chirita, Claudiu S. Firan and Wolfgang
Nejdl: Summarizing Local Context to Personalize
Global Web Search, the 15th Intl. CIKM Conf. on
Information and Knowledge Management, 2006,
USA.
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PROJECTS TECHNOLOGY ENHANCED LEARNING
ELAN – eLearning Academic Network Lower Saxony
The ELAN Pilot Hannover/Braunschweig coordinates the activities at the Leibniz University Hannover,
the Technical University of Braunschweig and the Hannover Medical School. The project aims to build a
broadly spread network of eLearning in different disciplines in the state of Lower Saxony, Germany. The
aim of the project is to develop and encourage sustainable eLearning projects and services and share
effective practice in eLearning projects. ELAN is fostering the sustainable use of digital and multimediabased
technologies in teaching and research. Appropriate use of these new technologies and eLearning
material can enhance the quality and experience of teaching and learning activities. This is closely connected
to the Bologna process and the idea of lifelong learning.
The two ELAN phases ELAN I (2002-2004) and ELAN II (2004-
2006) implemented an innovative approach to expand the
use of new multimedia technologies at the participating universities.
During the fi rst phase of the project the essential aim
was the formation of a central service group and the production
of an extensive content portfolio in four exemplary areas:
computer science/information technology, civil engineering
and architecture, education and continuing education of
teachers, and medicine. Since this time, numerous eLearning
courses have been created, implemented and put into
practice. Multimedia technology has become a regular part
of teaching and learning.
An important aim of the second phase of the project was to
strengthen the work of the pilot universities and the integration
of more institutes of higher education in Lower Saxony
into its networks of eLearning services. The driving forces of this
development are the two objectives jointly instigated by the
ELAN pilots: the lecture series “Lower Saxony Telecolloquium”
(www.telekolloquium.de) and the construction of the ELAN
Portal (www.elan-niedersachsen.de).
Lower Saxony Telecolloquium
The Lower Saxony Telecolloquium is an innovative, event in
which modern telecommunication technologies are used to
connect eight institutes of higher education in Lower Saxony
in a teleconference. The intention was to establish a supraregional
and inter-university event and to fi nd an effective way
to conduct and coordinate regional meetings in a distributed
manner. The event takes place periodically during the semester
and normally consists of three to fi ve presentations given
by invited speakers on a devoted topic. After the presentation,
the audience has the opportunity to ask questions and often
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
summary
The eLearning Academic Network (ELAN) is
dedicated to improving the eLearning activities
at the participating universities in Lower
Saxony. Six universities in Lower Saxony have
joined forces in order to develop sustainable
technical and organizational infrastructures
for multimedia teaching and learning and to
support a high-quality content portfolio.
a lively discussion ensues, across the different universities. The
Telecolloquium opens up possibilities for collaborative teaching
and learning and allows an intensive and uncomplicated
scientifi c exchange. Furthermore, it gives access to expertise
not available within a single institution. The Telecolloquium
buils on new audio-visual technologies and supplements the
traditional colloquia or small symposia. In total, 19 Telecolloquia
took place during May 2004 and December 2006. The
entire event has been evaluated positively by the involved university
participants.
ELAN Portal
During the last years, the project partners have carried out
many successful eLearning projects and activities. Therefore, a
major task was the integration of all relevant ELAN pilot information
into the ELAN Portal and the addition of new services
including a joint service catalogue. To aid the visibility and

Project Type: eLearning Academic Network funded
by the Ministry for Science and Culture of
Lower Saxony
Duration: October 2002 – December 2006
Research Areas: eLearning, collaborative working
Contact: Prof. Dr. Wolfgang Nejdl (nejdl@L3S.de)
Prof. Dr. Lars Wolf (wolf@ibr.cs.tu-bs.de)
Prof. Dr. Herbert Matthies (matthies@L3S.de)
URL: www.elan-niedersachsen.de
www.telekolloquium.de
dissemination of the eLearning activities at the participating
universities, the creation and maintenance of a central webservice
on which links to eLearning examples and resources
should be gathered was necessary. By building up the ELAN
Portal, the universities of Lower Saxony established a worldwide
accessible eLearning Service Portal. It presents eLearning
projects for a wider group of users and shows ways to arrange
own eLearning projects. The ELAN Portal will continue as a
central information base after the two phases of ELAN I and
II and will be maintained and advanced at the University of
Oldenburg.
What changes?
ELAN has made considerable strides to support the development
of multimedia technologies at the universities in Lower
Saxony, and to demonstrate different ways to embed eLearning
activities. This process has not only improved access developed
media competence of teachers and students, but also
developed the media competence of the teachers and the
students. In the future, eLearning will become a normal part
of university practice and complement traditional teaching
methods. With ELAN, the universities have a sound foundation
for further improvements.
TECHNOLOGY ENHANCED LEARNING PROJECTS
info box
selected publications
ELAN-Management Board (2007). ELearning Academic
Network Niedersachsen, Bericht zur Förderphase
ELAN II, (in preperation)
I. Herbold (2007). Das Niedersächsische Telekolloquium-
Öffentliche Ringvorlesungen zwischen
nord deutschen Hochschulen. In: Lehren und
Forschen mit Neuen Medien an der Leibniz Universität
Hannover. Shaker-Verlag (in preperation)
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
25

26
PROJECTS TECHNOLOGY ENHANCED LEARNING
EVITA – Efficient methods for Visualization
in Tele-immersive Applications
The EVITA project is concerned with the visualization of complex data resulting from massively-parallel,
four-dimensional simulations in the area of computational fl uid dynamics. Visualization enables researchers
to extract conclusions such as the fl ow of air pollutants within a city structure, and facilitates
an understanding of the underlying concepts. Other applications of the software developed in Evita are
molecular structures, deformation of bodies or applications where interactive visualization in 3D/4D
enhances cognition. By creating animated images from numbers, we enable researchers to get an intuitive
approach to results otherwise diffi cult to comprehend. The project is funded by the German Science
Foundation (DFG, ref. number GZ: OL 241/1-1).
The underlying concept
The software developed in “Evita” not only generates 2D images
varying in time, but also creates entire 3-dimensional
worlds which can be explored interactively and in a comfortable
way. The special advantages of the software – called
“DSVR” – are that users are able to manipulate the virtual
environment interactively and may look at the scene even
during a running simulation. The software supports the use of
sophisticated output devices such as a “Phantom” for haptic
output and stereo or multi-screen projection setup. Furthermore,
the software explicitly has been parallelized and ported
to supercomputers to avoid bottlenecks, such as a single computer
receiving large data sets from a computing cluster. The
data sets are quite large, and as a rule of thumb, the fi ner
and more precise the simulations get, the bigger the resulting
data will be.
Distributed virtual reality
The picture shows an excerpt from a meteorological setup
designed to analyze the distribution of pollutants in the air
around a rather tall building in the city of Hannover. Some
virtual “particles” are inserted at certain times into the running
simulation and then tracked to see how the chemicals
will be distributed. To get an idea about the process of distribution,
a trajectory line is added to each particle showing the
exact path of the molecules. The geometry of the buildings
themselves has to fi t to the numerical grid used for the simulation;
this makes the picture seem somewhat crude, but in
actuality it is quite detailed. The simulation depicted has one
of the highest resolutions that may be handled with today’s
computers.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
summary
Scientifi c visualization mainly aims at facilitating
an understanding of results. Evita is
a project concentrating on the visualization
of large and complex data sets resulting
from simulations running on supercomputers.
The software developed makes use of
the supercomputing environment to avoid
bottlenecks. It enables interactive viewing
of four-dimensional simulation results even
when the simulation is still running.
Illuminated streamlines and particles in a parallelized meteorological
large-eddy-simulation of Hannover use data obtained
by an in-fl ight laser scan as city model.
Usability
At times there can be many things going on simultaneously in
a simulation. Therefore, we experiment with alternative methods
to represent the data to the user – namely, using a haptic
device which enables “touching” the results of the simulation
or selecting where to show particle traces. Overcrowded
scenes are called “visually cluttered”, and should be avoided.
As a primary objective, data understanding should be facilitated,
and the goal is not to just create a representation that
may convey more information.

selected publications
Nils Jensen, Gabriele von Voigt, Wolfgang Nejdl,
Johannes Bernarding: Effi cient 1-Pass Prediction
for Volume Compression. SCIA 2005: 302-311.
Springer.
Nils Jensen, Gabriel Gaus, Gabriele von Voigt,
Stephan Olbrich: Design and Psychophysical Study
of Volume Compression for Haptic Rendering.
Accepted for publication at the World Haptics
Conference 2007, Tsukuba, Japan.
TECHNOLOGY ENHANCED LEARNING PROJECTS
info box
Project type: DFG-funded
Duration: March 2005 – March 2007 (first stage)
Research Areas: Visualization, Computer
Graphics, High-Performance Computing,
Numerical Simulation
URL: http://www.L3S.de/evita
Staff: Prof. Dr.-Ing. Stephan Olbrich,
Prof. Dr.-Ing. Gabriele von Voigt,
Gabriel Gaus, Nils Jensen
{olbrich, vonvoigt, gaus, jensen}@L3S.de
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER 27

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PROJECTS TECHNOLOGY ENHANCED LEARNING
HELCA – Hannover eLearning Campus
Setting up the future of learning
HELCA focuses mainly on the extension of traditional teaching with eLearning technologies, transferring
the results of previous projects into common practice for all faculty members of the University of Hannover.
Fundamental organizational changes are required and have to be coordinated within the overall
IT strategy of the university and the main partners on campus.
The state of the eLearning
The HELCA project started in July 2005. Its goal is the systemic
improvement, structural optimization and pervasive dissemination
of eLearning throughout the University of Hannover.
By creating an eLearning enhanced culture, HELCA will ensure
a permanent improvement in the effi ciency of teaching and
study-related services at the Leibniz University Hannover.
In 2006 the following milestones were achieved:
• The Learning management system Stud.IP is now being utilized
by around 5,000 active users. About 350 courses in the
winter semester 2006/07 benefi t from the available functionalities
of the system.
• The data of all offi cial courses and staff members are imported
and updated automatically from the corresponding
planning systems of the university. This automatic support
enables every staff member of the university to use Stud.IP for
their courses, with minimal overhead.
summary
The HELCA project makes eLearning a constituent
part of teaching at the Leibniz University
of Hannover. In 2006 we focused on
infrastructures and organizational activities,
which resulted in increased usage and awareness
of eLearning services. In 2007, it will be
necessary to establish ELSA as a permanent
institution within the university and to continue
winning new users.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
info box
Project Type: Service orientated integration
project funded by BMBF
Duration: July 2005 - June 2008
Research areas: eLearning, learning management
systems, IT and media services
Contact: Dipl.-Sozw. Cornelis Kater,
kater@L3S.de
URL: http://www.elsa.uni-hannover.de
http://elearning.uni-hannover.de
• All users of the learning management system now have the
possibility to ask for immediate help or to report any problems
while using the system by calling a dedicated hotline
number.
• A large number of institutes and individuals at the university
were given the required help using eLearning tools and also
had the opportunity to take part in tutorials and training lectures
on selected topics.
• Lecture recording is now supported by ELSA (eLearning-
Support-Abteilung). Many institutes have shown interest in
this utility and make use of the installed equipment to create
eLearning material in their courses.
• The learning-content management system ILIAS, for maintaining
on-line courses and assessments, was coupled with
Stud.IP and is now available for users at the university. Users
can access both systems with one account.
• The installation of the e-Classroom for supporting the interactive
presentation of learning contents starts at the beginning
of 2007.

Events for the masses
In order to increase the awareness of the support for eLearning
provided by ELSA at the Leibniz University Hannover for
both the students and teachers, two large-scale events were
organized in the year 2006:
Under the title: Willst du mit mir online gehen (would you go
online with me) all students – especially junior students – were
invited to an introductory lecture about the different onlineoffers
in the context of eLearning at the Leibniz University of
Hannover. In this lecture, ELSA made students aware of the
requirements of online-learning and successfully encouraged
them to explore the various possibilities and functionalities of
the eLearning platform Stud.IP. The lecture was presented in
the form of a show and was supported by some sponsors.
For the second group of users, namely the teachers, ELSA
has organized the fi rst eTeaching and eScience conference,
to which all employees of the university were invited. Fifteen
speakers presented their experiences with eLearning at the
Leibniz University of Hannover. More than 70 interested participants
attended this event.
TECHNOLOGY ENHANCED LEARNING PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
selected publications
Brehm, J., Olbrich, S.: HELCA - Ein Konzept für
einen E-Campus? SL05 – Workshop Structured
eLearning (Pre-Conference zur DeLFI 2005),
Rostock, 13.09.2005.
And we will go on…
In 2007 ELSA will take further steps for improving the provided
services, increasing the awareness of these services,
training the users. ELSA will also repeat and re-organize the
successful events of the year 2006.
The e-Classroom will start service this year, more connections
to the learning management system will be established (e.g.
digital collections, integrating the system with the offi cial web
site of the university) and new technologies like Podcasts will
be part of the offered services.
29

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30
PROJECTS TECHNOLOGY ENHANCED LEARNING
L3SCPD – L3S Center for Professional Development
The L3SCPD project focuses on a central research question, namely, how can innovative information,
as well as learning and knowledge technologies be used when establishing a knowledge society? For
this purpose, Ph.D. students are working with Professor Klaus Jobmann on didactical and methodological
issues. The goal of this work is to develop eLearning scenarios in an empirical way, the research
method focuses on the design-based research approach. With such as approach, general pedagogical
questions such as self-directed learning, student communication processes and the design of media are
addressed.
What has happened?
During the fi rst phase of the project, lectures were recorded at
the Institute of Communication Engineering (Leibniz University
Hannover) and made available on the Internet as a video
stream with slide accompaniment. Two years ago, lectures
were recorded interactively using automatic camera control.
Part of the concept is a “simple” lecture recording using the
authoring tool LECTURNITY®; which includes the interaction
between the students and the teacher. Based on the lecture
recordings, different eLearning scenarios in Distance Learning
and Blended Learning were conducted and the results of our
empirical evaluation were published.
What is going on?
Current work deals with further innovative eLearning scenarios
that are enabled through lecture recordings. Our goal is to
reduce the teacher-centred character of the media by creating
learner-centred scenarios [1]. Students learn in groups of two
or three using: a text guide, the normal lecture materials and
the recorded lectures. On the basis of the available media,
each group of students must answer the questions in the text
guide. The eLearning scenario is called VideoLern and was
also demonstrated in a vocational school. The evaluation results
and experiences were very positive. Students experience
great satisfaction with this kind of learning because they can
work independently. Teachers appreciate the great advantage
of not having to deliver content during classes and instead
can use this time for direct student supervision. An empirical
investigation of this eLearning scenario, which is built on the
design-based research approach, was designed, the investiga-
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
summary
L3SCPD means L3S Center for Professional
Development. Goal of this work is to develop
eLearning scenarios on an empirical way.
Actually the work focuses on a self-directed
eLearning scenario with lecture recordings.
Further works focus on the split-attention
problem during learning with lecture recordings.
tion will be carried out this year. In addition, the aspects of
self-directed learning and the teacher-student as well as student-student
communication processes will be measured.
Furthermore, a literacy study on the split-attention problem
during the use of lecture recording was carried out [2]. The
Research Center L3S worked together with the Freie Universität
Berlin and the Universität Osnabrück; the research results
give implications for the design of web lecture interfaces. Our
work so far suggests that eye-tracking measurement could be
an indication for the split-attention problem. Our plan is to
conduct a study that measures the learning effi ciency.

selected publications
Marc Krüger, Klaus Jobmann: Erfahrungsbericht
zum Lehren und Lernen mit eLectures. Vortrag auf
der 1. eLearning & eScience Tagung am 17.11.2006.
Paper will be published in March 2007
Robert Mertens, Gerald Friedland, and Marc
Krüger: To See or Not To See: Layout Constraints,
the Split-Attention Problem and their Implications
for the Design of Web Lecture Interfaces. Published
on e-learn World Conference on ELearning in Corporate,
Government, Healthcare, & Higher Education.
Honolulu, Hawaii, Oct. 13-17, 2006
TECHNOLOGY ENHANCED LEARNING PROJECTS
info box
Project Type: Research and Application Project
Duration: 2003-2007
Research areas: Technology Enhanced Learning
Contact: Prof. Dr.-Ing Klaus Jobmann,
Dipl.-Berufspäd. Marc Krüger
{jobmann, krueger}@L3S.de
URL: http://www.L3S.de/l3scpd
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PROJECTS TECHNOLOGY ENHANCED LEARNING
mstbildung – Net Based Strategies for
Qualification in Microsystem Technology
Microsystem Technology has played an increasingly important role for growth and employment and is
likely to be a key technology in the 21th century. Due to the fact that a growing number of companies
is using microsystem technologies and seeking employees with broad and comprehensive knowledge; it
is becoming diffi cult to satisfy the demand for skilled labour. The current system of college degrees and
vocational training is not creating enough specialists. Consequently, there is a huge demand for training
and continuing professional development.
Education Network Lower Saxony
The project mstbildung (Microsystem Technology Education)
is part of an educational network aiming to promote
microsystem technology in Lower Saxony. Companies, research
and educational institutes have joined forces in order
to promote education and training in an interdisciplinary and
cross-technology manner. Focusing on Microsystem Technology,
the project investigates an approach that can fulfi ll the
demand for qualifi cation and lifelong learning by using netbased
teaching and learning strategies. The required resources
are developed by the L3S Research Center, in co-operation
with the Center for Technical Didactic, Leibniz University of
Hannover and provided via an Internet training and learning
platform.
Multi-medially Learning with Ilias
Within the mstbildung network, one fundamental aim is to
develop teaching and learning material to support vocational
schools in the region. To provide a wide range of material,
an opensource web-based Learning Management System,
called Ilias, was installed on a L3S server. Ilias allows users to
create, edit and publish learning and teaching material in an
integrated system using their normal web browsers, making
it easily accessible for all participants. Tools for cooperative
working and communication are included as well. Trainees
can access Ilias anytime and follow their own working and
learning rhythm.
The multimedia supported learning units are dealing with
typical microtechnology tasks with great applied relevance.
All project courses follow the principle of “complete action”.
The individual phases are carried out by trainees in different
learning locations within the educational network, such as vo-
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
cational school, companies, and laboratory. The trainees are
exposed to a new topic through multimedia teaching materials
chosen by their teachers. Every multimedia teaching unit is
illustrated by numerous pictures, movie sequences and comments.
The use of this material helps to link the fundamental
skills and knowledge with excercises. By doing this, trainees
are better prepared for practical phases, such as working in a
cleanroom.
The use of multimedia technology has provided many encouraging
outcomes. The experience shows that multimedia
teaching and learning material has aided the student learning
process. Study techniques become more active and effi cient
and the approach generates greater interest in the units and
encourages the trainees to work more diligently. In addition
teachers and trainees gained experience in multimedia technology
by using the Learning Management System Ilias. In
sum, Ilias maximizes social, contextualized, and problem focused
learning.
selected publications
A. Weiner (2007), Kooperatives Lernen in projektorientierten
Lehrveranstaltungen. In: Lehren und
Forschen mit Neuen Medien an der Leibniz Universität
Hannover. Shaker-Verlag (in preperation)
R. Sandvoss (2006), Innovative Strategies of
Qualifi cation in Microsystem Technology. In: International
newsletter in micro-nano integration,
No.06/06, VDI/VDE-IT, Berlin

TECHNOLOGY ENHANCED LEARNING PROJECTS
summary
To supply the microsystem technology
branch with well-educated and inter-discipline
workers a high level of education and
professional training is needed. The education
has to include generic skills as well as
professional subjects. The project mstbildung
creates a net-based teaching and learning
environment, which helps all participants
to acquire new and important technical
knowledge. These net-based teaching and
learning strategies fulfi ll the demand for
qualifi cations and lifelong learning. With the
help of the Learning Management System
Ilias, teachers and trainees can be qualifi ed
co operatively.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
info box
Project Type: Educational Network funded by
the German Federal Ministry of Education and
Research (BMBF)
Duration: Januar 2003 – December 2007
Research Areas: self-directed learning,
eLearning
Contact: Akad. Rat Andreas Weiner,
weiner@zdt.uni-hannover.de
Dipl.-Ing. Inga Herbold, herbold@L3S.de
URL: http://www.mst-bildung.de
33

34
TECHNOLOGY ENHANCED LEARNING
PROLEARN –
Network of Excellence in Professional Learning
L3S coordinates the Network of Excellence PROLEARN, which integrates European research in the fi eld of
professional learning. The network consists of 21 internationally renowned partners, over 240 researchers
and about 300 associated participants. PROLEARN stimulates cooperation and new initiatives, and
plays a major role in disseminating the research results. Various events are organized for researchers and
professionals, such as the annual Summer School for Ph.D. students, Professional Training Facts and the
European Conference on Technology-Enhanced Learning.
Summary of Activities
PROLEARN is a Network of Excellence dealing with technology
enhanced professional learning. Our mission is to bring
together the most important research groups in the area of
professional learning and training, as well as other key organizations
and industrial partners. The Network the currently
existing gap between research and education at universities
and similar organizations and training and continuous education
that is provided for and within companies.
The PROLEARN network aims to integrate research on relevant
topics. Explicit attention is paid to the identifi cation of
new topics, in order to set up a roadmap for future research in
the fi eld of technology-enhanced learning in Europe. To reach
this goal, community building is essential, in particular via the
organization of scientifi c events.
summary
PROLEARN is a Network of Excellence dealing
with technology enhanced professional
learning. Our mission is to bring together
the most important research groups in the
area of professional learning and training, as
well as other key organizations and industrial
partners. PROLEARN bridgets the currently
existing gap between research and education
at universities and similar organizations
and training and continuous education that
is provided for and within companies.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
Research
The PROLEARN research topics are clustered as follows:
interoperability; competencies and personalization; business
processes and learning; and collaborative learning. The results
are refl ected in a large number of scientifi c publications
in conference proceedings and journals, as well as in various
project proposals. Research exchanges refl ect ongoing joint
projects within the PROLEARN context.
Another important outcome in 2006 has been the foundation
of the Professional Learning Cluster PRO-LC. PRO-LC connects
major European research projects in the area of Technology
Enhanced Learning which focus on professional learning,
including PROLEARN and the Integrated Projects Prolix,
APOSDLE, TENCompetence and Palette. Through close cooperation,
these projects aim to strengthen European research
and industry in the area of professional learning, for example
through standardization bodies.
With its activities, PROLEARN is reshaping research in technology-enhanced
learning in Europe. PROLEARN joint research
and activities have proven to be a successful base for
joint collaboration in new projects and events focusing on
new and important research issues.
Events
A major PROLEARN focus has been the establishment, maintenance
and initiation of joint activities, events and projects in
2006. In addition to workshops and dissemination events at
– among others – Adaptive Hypermedia 2006, ICALT 2006,
I-KNOW 06 and WWW 2006, the two main events were the
Summer School 2006 and the fi rst European Conference on
Technology-Enhanced Learning EC-TEL 2006.

The PROLEARN Summer School 2006, held in Bled, Slovenia,
attracted 71 participants representing 29 nationalities. The
summer school featured lectures given by professors, various
workshops and mentoring activities. The summer school was
useful in promoting participation at the fi rst PROLEARN Doctoral
Consortium to be held at the EC-TEL conference.
EC-TEL 2006 took place in Crete, Greece. Thanks to the ambitious
and competitive selection process (acceptance rate was
22%), EC-TEL 2006 managed to bring together the leading
experts in the fi eld of technology-enhanced learning. The
main goal of the conference was to support a forum for European
research, which was emphasized by the presence of
representatives from the EC and by eight EU/IST project meetings
focusing on technology enhanced learning. It was a very
good start for the newly created EC-TEL conference and we
look forward to its continued success.
Future
Several sustainability activities have been developed in order
to ensure the continuation of the PROLEARN activities. The
PRO-LC will take care of the organization of the Summer
Schools and EC-TEL conferences. In order to provide a legal
basis for these activities, an association will be founded by
February 2007.
TECHNOLOGY ENHANCED LEARNING
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
info box
Project Type:
Network of Excellence, funded by EU PF6
Duration: January 2004 – December 2007
Research: Professional Learning, Technology-Enhanced
Learning, Collaborative Learning, Personalization,
Knowledge Management, Standardization
Contact: Dr. Eelco Herder, herder@L3S.de
URL: http://www.prolearn-project.org
selected publications
Philipp Kaerger, Carsten Ullrich, Erica Melis:Integrating
Learning Object Repositories Using a
Mediator Architecture. In: Proceedings of the First
European Conference on Technology Enhanced
Learning (EC-TEL‘06), Springer LNCS, Crete, Greece,
October 2006.
Martin Wolpers, Margit Hofer, Gunnar Martin:
Professional Learning in Europe and beyond - Structures
for sustainable TEL-Research. In: Proceedings
of the First European Conference on Technology
Enhanced Learning (EC-TEL‘06), Springer LNCS,
Crete, Greece, October 2006.
Jehad Najjar, Martin Wolpers, Erik Duval: Towards
Effective Usage-Based Learning Applications: Track
and Learn from User Experience(s). In: Proceedings
of the 6th IEEE International Conference on
Advanced Learning Technologies (ICALT 2006),
Kerkrade, The Netherlands, July 2006.
35

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TECHNOLOGY ENHANCED LEARNING
PROLIX – Process-oriented Learning
and Information Exchange
Modern enterprises use information technology both to control and manage their business processes
and to manage and administer employee learning processes. Currently however, the respective systems
are completely independent of each other, making the alignment of business process changes and corresponding
personnel development tedious and ineffi cient. The main goal of PROLIX is to support learning
processes aligned with business processes; thereby enabling organizations to improve the competencies
of their employees faster and more effi ciently according to the continuous changes of business requirements.
Challenges
PROLIX aims to support a complete learning process life cycle.
This life cycle starts with the analysis of complex business situations,
followed by the identifi cation of individual and organisational
learning goals, the analysis of competencies and their
matching with individual skills. Based on this analysis, appropriate
learning strategies and actual courses are selected or
developed. Success of the learning process execution and the
learner’s actual performance at the work place are constantly
monitored, providing valuable feedback to business process
designers and human resource managers.
This approach imposes several challenges, among them:
• Development of a comprehensive competency model: The key
to interconnection of business and learning processes is the
concept of competency profi les. Such profi les are used to describe
current employees skills, the skills required to conduct
a business task, and the competencies obtained by taking a
specifi c course or course element.
• Design of a service-oriented integration architecture: The integration
of business and learning processes also has to take place
on a technical level. PROLIX does not build a new information
system for that purpose from scratch, but instead takes advantage
of existing, mature systems reusing them as software
components. The challenge is to defi ne suitable interfaces for
these components to enable a loose technical coupling which,
at the same time, provides a tight functional integration.
R&D Highlights
Competency model: An extensive framework for description
of competency profi les has been created, which allows attaching
competency-related information to several concepts
as person, process, role, function, course, learning template,
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
summary
The vision of PROLIX is to enable business
process driven learning at the workplace,
taking into account individual learners
and their needs as well as the corporate
requirements. To realize this vision, PROLIX
will create a process- and competency-driven
software framework for interlinking business
process intelligence tools on the one hand
with knowledge management and learning
environments on the other.
etc. This framework allows capturing complex competencies
along with supplementary information such as evidence records.
It is possible to compose competency defi nitions from
existing descriptions, and relations between competencies
(e.g. inclusion) can be stated. This fosters reuse and will lead,
in the long term, to a network of – possibly standardized
– competency specifi cations.
PROLIX architecture: A major achievement in 2006 was the
fi rst architecture specifi cation. In addition to business process
management and learning management systems, components
for competency profi le management, process simulation,
learning process creation and process monitoring had to
be integrated. For all these components, interfaces, interaction
patterns, and data formats have been defi ned. As a technical
foundation, the system is using the Service Oriented Architecture
paradigm based on an Enterprise Service Bus. This type of
infrastructure decreases component coupling signifi cantly and
allows for fl exible system composition and confi guration.

In 2007, this system will be installed at selected corporations
and institutions from telecommunications, health care, and
fi nance to evaluate its usage and gather input for their further
development. The next research activities will focus on
effi cient matching of competency profi les to requirements
and fl exible workfl ow support for the service-oriented architecture.
Project Type: Integrated Project funded by EU
Duration: December 2005 – December 2009
Research Areas: Technology Enhanced Learning,
Service-oriented Architectures
Contact: Dr. Wolf Siberski, siberski@L3S.de
URL: http://www.prolix-project.eu
TECHNOLOGY ENHANCED LEARNING
info
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
selected publications
Juri L. De Coi, Eelco Herder, Arne Koesling, Christoph
Lofi , Daniel Olmedilla, Odysseas Papapetrou,
and Wolf Siberski. A Model for Competence Gap
Analysis. Proceedings of the 3rd International
Conference on Web Information Systems and
Technologies (WEBIST), Barcelona, 2007.
Wolf Siberski, Christoph Lofi , Odysseas Papapetrou.
PROLIX Functional Architecture. Technical
Report, 2007.
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TECHNOLOGY ENHANCED LEARNING
TENCompetence – Building the European Network
for Lifelong Competence Development
Traditionally, instructional learning has covered the needs of people searching for new labor opportunities,
be it to improve or upgrade in current jobs or search for new ones. Normally, the learning process
would start with some formal curriculum (e.g., at the university level) and then be followed by some
specifi c courses related to the area of work (e.g., an MBA). Nowadays, there is a growing need for more
fl exible and cost-effective solutions for learners in order to provide lifelong competence development.
People need the possibility to learn at different locations (e.g.,
at home) and at times that better fi t their working hours while
still keeping most of the benefi ts of face-to-face learning, for
example, the availability of tutors to help them if a question
arises. TENCompetence addresses this need and aims to
support individuals, groups and organizations in Europe in
lifelong competence development by establishing the most
appropriate technical and organizational infrastructure and
using open-source, standards-based, sustainable and innovative
technology.
The project focuses on new pedagogical models, fi nding the
best solutions, pro-active sharing, assessment, support tools,
decentralized management and integration of isolation tools
by conducting research within the following four areas:
summary
The aim of TENCompetence is to support
individuals, groups and organizations in
Europe in lifelong competence development
by establishing the most appropriate technical
and organizational infrastructure, using
open-source, standards-based, sustainable
and innovative technology. Research focuses
on four specific areas: knowledge resources,
learning activities, competence development
programs and learning networks.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
Knowledge Resource Sharing and Management
The TENCompetence infrastructure requires a knowledge resource
sharing and management middleware as basis in order
to ensure the availability of resources as well as their proper
exchange and use. Moreover, learners should be able to share
their resources and access resources from other learners as
well. Such middleware brings together: centralized repositories
(e.g., institutional servers and Learning Management
Systems); decentralized networks (e.g., Peer-to-Peer); emergent
Web2.0 applications (e.g., Flickr or YouTube). In this way
TENCompetence provides new means for users to share information
with a higher level of motivation.
Learning Activities & Units of Learning
Units of learning are activities designed and directed to the
attainment of a learning object by a person. They add pedagogical
information to knowledge resources. In this area, new
pedagogical models and tools for the creation and management
of units of learning are needed in order to provide a
more complete overview of the learning process and facilitate
the integration of individual and collaborative learning for
persons, groups and institutions.
Competence Development Programmes
Lifelong learning requires not only accessing existing formal
curricula but also ad-hoc programmes (collections of units of
learning) provided by i.e. other learners based on their experience:
thereby increasing dramatically the options of the learners.
Due to the lack of standards for describing Competence
Development Programmes in a formal, semantic and interoperable
way, TENCompetence will provide such a specifi cation

and use it to help users position themselves within a learning
network as well as give recommendations based on their profi
le and goals.
Networks for Lifelong Competence Development
These networks are collections of Competence Development
Programmes defi ned within a knowledge domain. TENCompetence
aims at providing a general vision of the content of
such networks as well as the people participating in them. In
addition, new models for the stimulation of proactive collaboration
among learners based on software agents, games and
simulations, as well as visualization of communities and social
networks will be provided.
Project type: Integrated Project
Duration: December 2005 - November 2009
Research Areas: eLearning, Knowledge sharing,
SOA, Personalization, Social networks
Contact: Daniel Olmedilla, olmedilla@L3S.de
URL: http://www.tencompetence.org
TECHNOLOGY ENHANCED LEARNING
info box
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
selected publications
Ingo Brunkhorst and Daniel Olmedilla. Interoperability
for peer-to-peer networks: Opening p2p to
the rest of the world. In Innovative Approaches for
Learning and Knowledge Sharing, First European
Conference on Technology Enhanced Learning (EC-
TEL), volume 4227 of Lecture Notes in Computer
Science, pages 45-60, Heraklion, Greece, Oct 2006.
Springer.
Frans Van Assche, Erik Duval, David Massart, Daniel
Olmedilla, Bernd Simon, Stefan Sobernig, Stefaan
Ternier, and Fridolin Wild. Spinning interoperable
applications for teaching & learning using the
simple query interface. Educational Technology &
Society. Special Issue (April 2006) on Interoperability
of Educational Systems, 9(2):51-67, 2006.
Bernd Simon, Stefan Sobernig, Fridolin Wild, Sandra
Aguirre, Stefan Brantner, Peter Dolog, Gustaf
Neumann, Gernot Huber, Tomaz Klobucar, Sascha
Markus, Zoltán Miklós, Wolfgang Nejdl, Daniel
Olmedilla, Joaquín Salvachúa, Michael Sintek, and
Thomas Zillinger. Building blocks for a smart space
for learningtm. In 6th IEEE International Conference
on Advanced Learning Technologies (ICALT 2006),
pages 309-313, Kerkrade, The Netherlands, July
2006. IEEE Computer Society.
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SEMANTIC WEB AND DIGITAL LIBRARIES
APIS – Advanced Personalization
in Information Services
Due to the ever growing volume of database content and the personalization needs in information
searches, human preferences play an essential part in today’s information systems. This is because mere
traditional database queries quite often produce empty or too numerous results. The user is frustrated
in both cases and feels left alone facing the information fl ood. The APIS Group at L3S Research Center
investigates personalized service provisioning based on individual sets of personal preferences for each
user. Such preference sets not only best express user’s information needs, but also state the trade-offs
each user is prepared to consider. In short, respecting user preferences and effi cient preference handling
are essential building blocks towards truly cooperative information services.
Focus on Cooperative System Behavior
Cooperative information systems offer user-centered querying
by automatic relaxation of (less important) query parts.
Today, most systems use complicated ranking schemes to
express the utility of information with respect to the query.
However, the practical applicability in large information
sources still remains rather limited: generally users cannot be
expected to provide meaningful weightings for a complex
utility function and subsequently, neither can calculated rankings
be explained intuitively to the user.
Therefore, recently the skyline query paradigm has been applied
in a variety of applications ranging from digital item
adaptation to location-based information services. In skyline
queries, the user merely specifi es basic predicates to be queried
and in return, an optimal result set is always retrieved. A
summary
APIS aims at personalized service provisioning
based on individual sets of personal
preferences for each user. These preferences
are part of a flexibly adaptable profile and
more necessary information can be elicited
on demand directly from users. Directly focusing
on the users’ information needs APIS
thus investigates technologies to efficiently
provide ‘prime cuts’ of all available information
in an interactive and cooperative query
process.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
info box
Project Type: DFG Project within the Emmy Noether
Program of Excellence
Duration: November 2004 – October 2008
Research Areas: Databases and Information Systems,
Service Provisioning, Personalization
Contact: Dr. Wolf-Tilo Balke, balke@L3S.de
URL: http://www.L3S.de/apis
user simply cannot miss any important answer. However, the
advantage of intuitive query formulation comes at a price: on
the one hand, skylines are rather expensive to compute; on
the other hand skylines are known to grow exponentially in
size with increasing number of query predicates. Thus, the
user again has to face the information fl ood.
Focus on Interactive Query Processes
The APIS approach works together with the user to personalize
results and supports refi nements of the individual
preference profi le. Users are enabled to interactively specify
additional preference information, as well as equivalences between
choices, leading to an incremental reduction of result
set sizes. Users can thus even express trade-offs or compromises
they are willing to consider and can also intuitively adjust
imbalances between fi ne-grained and coarser preference
specifi cations.
In all these tasks, the APIS system effi ciently supports the user
by automatically taking care that newly specifi ed preferences
and equivalences will never violate the consistency of previ-

ously stated preferences. Users will not encounter confl icts
and will understand how their information need shapes the
result set. Moreover, the effi cient algorithms developed in the
preference handling framework allow the retrieval of focused
result sets, respecting real time constraints even over large information
collections.
The benefi ts of APIS’s personalized information services are
pervasive information access with proactive support for information
search and retrieval. Together with innovative wireless
technologies and powerful client devices, these services help
to provide the right information anytime, anywhere. The APIS
project is committed to bringing together researchers from
different disciplines to improve the personalization capabilities
in today’s information services. APIS is funded by the German
Research Foundation as part of the Emmy- Noether-Program
of Excellence.
SEMANTIC WEB AND DIGITAL LIBRARIES PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
selected publications
Wolf-Tilo Balke, Ulrich Güntzer, and Christoph Lofi
Eliciting Matters – Controlling Skyline Sizes by
Incremental Integration of User Preferences. International
Conference on Database Systems for
Advanced Applications (DASFAA), Bangkok, Thailand,
2007.
Wolf-Tilo Balke, Ulrich Güntzer, and Wolf Siberski
Getting Prime Cuts from Skylines over Partially
Ordered Domains. GI-Fachtagung für Datenbanksysteme
in Business, Technologie und Web (BTW),
Aachen, Germany, 2007.
Wolf-Tilo Balke, Ulrich Güntzer, and Wolf Siberski
Exploiting Indifference for Customization of Partial
Order Skylines. International Database Engineering
& Applications Symposium (IDEAS), Delhi, India,
2006.
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SEMANTIC WEB AND DIGITAL LIBRARIES
PUMA – Personalized Universal Media Access
The Personalized Universal Media Access (PUMA) project at L3S Research Center embraces the vision of
accessing multimedia data anywhere anytime from a variety of (mobile) client devices. Today this is usually
facilitated out of a plethora of complex monolithic applications. But building and maintaining such
complex large scale multimedia systems is always a diffi cult, costly, time-consuming and challenging
problem. Service-based architectures and the possibility to fl exibly reuse services for different workfl ows
and compose basic services to implement more complex workfl ows or rather execution fl ows, as proposed
in the Web and Grid communities, can provide a possible solution to this problem.
Flexibility and Reusability by Service Orientation
Service-oriented computing and service-oriented architectures
are concepts strongly discussed and researched in the
Web and Grid communities today. With the advent of frameworks
and languages to build and manage Web services and
protocols to enable conversations between them, much work,
mostly driven by industry alliances has been invested in standardization.
Generally speaking, Web applications can already
now be fl exibly modeled using services as basic building
blocks. Beside the effi cient provisioning and improved reusability
of components, the move from data-driven to servicedriven
Web architectures promises to open up a whole new
fi eld of value-adding applications.
PUMA develops these applications on top of existing components
and thus reuses individual services to form new and increasingly
complex workfl ows in a time- and cost-aware manner.
Moreover, new innovative business models for content-,
service- and network-providers can be employed and used for
mutual benefi t.
info box
Project Type: Leibniz University of Hannover
project in the framework ’Innovationsschwerpunkt
Service Oriented Architectures’.
Duration: August 2006 – September 2008
Research Areas: Multimedia Systems, Serviceoriented
Architectures, Personalization
Contact: Dr. Wolf-Tilo Balke, balke@L3S.de
URL: http://www.L3S.de/puma/
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
summary
The Personalized Universal Media Access
(PUMA) project embraces the vision of accessing
multimedia data anywhere anytime
from a variety of (mobile) client devices.
Composing the necessary tasks as basic
building blocks in a service-oriented architecture
promises to introduce maximum
flexibility and reusability for components
when building advanced and highly personalizable
multimedia applications.
Cost-efficient Multimedia Application Development
Given the enormous development costs for large scale applications
the multimedia community is currently on the move
from monolithic multimedia applications to more fl exible
solutions. PUMA focuses especially on the domain of data
semantics. The multimedia community already provides sophisticated
standards for media coding accompanied with
meta-data descriptions (e.g. MPEG-7, MPEG-21). Nevertheless,
useful concepts from Web services research on dynamically
building complex applications and execution fl ows using
semantically well-defi ned descriptions did not make a broad
impact on multimedia systems development yet.
Multimedia applications are generally fl ow-based applications,
since their data usually are continuous streams (e.g.,
video and audio streams), i.e. dependent in time and space.

Quality constraints often need to be taken into account, adding
another dimension. Hence, due to the rich semantic relations
of multimedia data, and their time and space dependencies,
functional services end up with rich dependencies, and it
makes the building of large scale multimedia applications and
systems truly challenging. To build a large scale distributed
multimedia application, the underlying system infrastructure
must provide a strong support across multiple protocol and
service layers for the overall service composition process.
Advanced Personalization Tasks
Managing and delivering multimedia content over a variety of
devices in a service-oriented and personalized fashion also puts
great demands on the selection and adaptation of content.
For every individual user a specifi c workfl ow has to be created
respecting the user’s content preferences, con-tent semantics
and network constraints, as well as terminal capabilities. Depending
on the available media, the discovered services and
all semantic, user-specifi c and technical constraints, the selection
of the best possible workfl ow needs to solve a complex
preference problem. By integrating a model of partial order
preferences and developing algorithms to effi ciently evaluate
complex preference constraints, the PUMA framework is able
to handle such trade-offs in a more meaningful way.
SEMANTIC WEB AND DIGITAL LIBRARIES PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
selected publications
Benjamin Köhncke and Wolf-Tilo Balke
Personalized Digital Item Adaptation in Service-
Oriented Environments.
International Workshop on Semantic Media Adaptation
and Personalization (SMAP), Athens,
Greece, 2006.
Wolf-Tilo Balke and Jörg Diederich
A Quality- and Cost-based Selection Model for
Multimedia Service Composition in Mobile Environments.
IEEE International Conference on Web
Services (ICWS), Chicago, IL, USA, 2006.
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SEMANTIC WEB AND DIGITAL LIBRARIES
P2P-IS
Peer-to-Peer Information Systems
P2P-IS is devoted to conducting basic research in the area of P2P networks for information systems. In
2006, new coordination approaches for routing of keyword queries were explored. Also, previous work
was extended to allow more expressive queries, taking into account user preferences. Additionally, progress
was made in the area of distributed reasoning algorithms, and in interconnecting P2P networks with
service-oriented information systems.
P2P Information Retrieval
In the last years, L3S has worked on an information retrieval
P2P network, allowing for effi cient keyword search in distributed
document collections. Currently, this network uses
a super-peer backbone for distribution of queries. While this
works effi ciently, it relies on the availability of performant
network nodes to bear the burden of analyzing and routing
queries. Therefore, it is attractive to use a less centralized infrastructure
for query routing, such as a distributed hash table
infrastructure (DHT). We have devised an information retrieval
network where clusters of peers are coordinated by such a
DHT. New peers contact the DHT to fi nd the right cluster, and
register in the network. Due to careful selection of distinguishing
keywords, this registration process affords only few interactions
with the DHT. A querying peer fi rst contacts the DHT
to retrieve the relevant clusters, and then contacts a cluster
representative directly for further query routing. This ensures
that for any query, only a small fraction of the network is involved
in the processing.
With the availability of more and more structured data about
documents and their contexts (e.g., due to Semantic Web annotations),
it becomes desirable to include search conditions
related to this additional information. Our distributed top-k
evaluation algorithm which takes into account the subject to
fi nd most relevant documents has been generalized such that
preferences with respect to any additional information are
considered for the identifi cation of the most relevant documents.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
summary
Information systems such as digital libraries
or learning object repositories are becoming
increasingly interconnected. Currently, these
networks are manually administered, leading
to high effort and low flexibility. Thus, it
is appealing to move towards self-organized
networks, where information sources can
join open information networks easily. P2P-
IS conducts research to make such networks
feasible.
P2P Reasoning
For complex coordination tasks, e.g., distributed policy checking,
peers in an information network need to perform a distributed
reasoning and proof process. This is a challenging
task because the network has to make sure that the reasoning
process always terminates, although there is no central
control. The key to tackling this challenge is an adaptation
of the tabling algorithm for the distributed case. For a goal
occurring during the reasoning process, a table is created
where answers for this goal are stored as soon as they are
found. Since repeated answers are not propagated, looping is
avoided and program termination is guaranteed.
P2P System Integration
While P2P networks offer a high degree of self-organization
and a scalable interconnection facility, they also require all

participating nodes to implement a network-specifi c interface
and protocol. For existing systems, this poses a high entrance
barrier, due to signifi cant development efforts for the required
adaptation. L3S has devised a concept and implemented an
infrastructure which allows sharing of content between the set
of peers inside a P2P network and other systems outside the
network. The approach uses proxy nodes and semantic mappings
to translate the proprietary P2P protocol to an open,
standard-based web service interface. This interface can be
used seamlessly by any system capable of offering and/or calling
web services, thus lowering the entrance barrier signifi -
cantly.
Project Type: Base Funding
Duration: since 2001
Research Area: Peer-to-Peer Networks
Contact: Dr. Wolf Siberski, siberski@L3S.de
URL: www.L3S.de/english/projekte/edutella.html
SEMANTIC WEB AND DIGITAL LIBRARIES PROJECTS
info box
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
selected publications
Wolf Siberski, Jeff Z. Pan, and U. Thaden. Querying
the Semantic Web with Preferences. Proceedings
of the 5th International Semantic Web Conference
(ISWC), Athens, GA, USA, 2006. Best Student Paper
Award
Loizos Michael, Wolfgang Nejdl, Odysseas Papapetrou,
Wolf Siberski: Improving distributed join
effi ciency with extended bloom fi lter operations,
The IEEE 21st International Conference on Advanced
Information Networking and Applications
(AINA-07)
Odysseas Papapetrou, Wolf Siberski, Wolf-Tilo
Balke, Wolfgang Nejdl: DHTs over Peer Clusters for
Distributed Information Retrieval , The IEEE 21st
International Conference on Advanced Information
Networking and Applications (AINA-07)
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SEMANTIC WEB AND DIGITAL LIBRARIES
ELEONET – European Learning Objects Network
While the European market of digital Learning Objects is rapidly growing, the prospective customers still
face diffi culties searching for an appropriate Learning Object. When traditional learning materials, such
as textbooks, are referenced via ISBN identifi ers. Digital Object Identifi ers are still unknown to producers
of learning content. The ELEONET project aims at creating a European catalogue of educational materials
offering an added value service to all the actors involved within the eLearning value chain, such as
content producers, learning communities and intermediaries.
Challenges
The current situation among national learning repositories
suffers from three main problems:
• Market Lock-In. National repositories contain the learning
objects which can be used outside the local market. At the
same time, there are no facilities to allow a Europe-wide exchange
of the learning information.
• No central search. When users are aware that many repositories
can be relevant for fi nding an appropriate Learning Object,
they still do not have a single search interface to query all
of them at once, especially for school material.
• No standard identifi er for Learning Objects. Finally, when a
Learning Object is known, its URL can be outdated and there
is no way to access it. We need an identifi er with a permanent
link to the object, which will help to fi nd it at any time.
Project Results
By offering to the European teaching communities an easy
and unifi ed access to educational resources, ELEONET increases
the content producers’ opportunity to disseminate their
learning objects throughout Europe, ensuring a wider visibility
and thus enhancing the market growth. Digital content available
through the ELEONET catalogue is identifi ed using the
Digital Object Identifi er (DOI), the international standard for
identifying and describing any Intellectual Property in a digital
environment. ELEONET allows Learning Object producers to
assign DOIs and to register metadata onto any content.This is
done according to a metadata schema interoperable with the
existing standards implemented at EU and international level.
The DOI registration system includes an editor to ease the
input of educational metadata. Schools, teachers and learn-
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
info box
Project Type: Specific Targeted Research
Project funded by EU
Duration: January 2006 – June 2007
Research Areas: eLearning
Sergey Chernov, chernov@L3S.de
URL: http://www.eleonet.org
ing communities, in general, can access the ELEONET metadata
and DOI repository through a search engine available
in four European languages (English, Spanish, German and
Italian) allowing both simple and advanced search by widely
accepted criteria: educational level, title, etc. ELEONET offers
Learning Object producers an effective solution for standard
identifi cation and metadata management of their own contents
through a single access point.
Potential Users
There are three expected categories of users:
• Content producers, which will assign DOIs to Learning
Object and register metadata;
• Intermediaries, which will exploit the existence of the standard
to facilitate the identifi cation of Learning Objects and
metadata collection;
• End users, which will search the metadata to retrieve appropriate
content.
Content producers will include different type of organisations.
Educational publishers are the fi rst target group, but not the

only one. Many other organisations entered the market in
recent years, such as non-profi t entities, technological and
telecom enterprises, media companies other than publishers,
multimedia publishers and so on. Sometimes educational organisations
are responsible for content production. Schools or
individual teachers, universities, training organisations, etc.,
often produce content. Therefore, they also belong to an important
target group to which ELEONET will give the possibility
to register DOI and increase the possibility to disseminate
Learning Objects to other educational institutes, stimulating
the re-use of educational content.
SEMANTIC WEB AND DIGITAL LIBRARIES PROJECTS
selected publications
Jan Brase, Sergey Chernov and Alvaro Ordóñez,
ELEONET: The search portal for learning objects:
IV International Conference on Multimedia and
Information and Communication Technologies in
Education (m-ICTE) 2006
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
summary
ELEONET is an emerging European search
portal for Learning Objects being associated
with Digital Object Identifiers (DOI).
ELEONET allows creators and publishers to
obtain the DOIs for their Learning Objects
and to upload the corresponding metadata.
Within the eLearning value chain, ELEONET
is aiming to connect the major national
learning repositories, provide interoperability
on a European scale between all organizations
involved in the eLearning value chain.
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SEMANTIC WEB AND DIGITAL LIBRARIES
NEPOMUK – Building the Social Semantic Desktop
PC desktop users are facing more and more data every day. Structuring and organizing the Personal Information
Repository is thus becoming a serious problem. This is why, in some cases, it is faster to fi nd a
document on the World Wide Web, even though we know we stored it somewhere on our desktop. NEPO-
MUK addresses these challenges and provides solutions to support the personal knowledge lifecycle of
each person, as well as assists in information sharing and management.
2006 Challenges Overview
As a three year EU project with 16 major partners, NEPOMUK
focused, in its fi rst year, on building the foundations of what
is to become “The Social Semantic Desktop”. Several areas
needed to be tackled in order to fulfi ll such a forward-looking
goal. First, there is of course the knowledge articulation
and linkage into Semantic Web data structures at the desktop
level. Once accomplished, this needs to be backed by social
communication services as well, in order to enable fast and
effective information exchanges. Finally, all results need to be
extensively tested within various case studies, as well as widely
disseminated across representative scientifi c communities and
beyond.
R&D Highlights and Results
Enhancing Desktop Search: L3S covers a highly innovative
role within NEPOMUK, both within the local and social en-
summary
The first year of NEPOMUK proved to be a
very successful one, not only for L3S, but
also across the entire project consortium.
We managed to build solid foundations for
the research to come in the next two years,
while at the same time being already able to
design and publish a series of initial results.
We are confident in keeping up the good
work within 2007 as well, for both local and
social network environments.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
vironments. Thus, in 2006, we continued our work on the
Beagle++ Desktop Search infrastructure and extended it with
high quality metadata generation modules, and especially
with at least two novel approaches to ranking personal items.
The fi rst one, published at the European Semantic Web Conference,
is based on the analysis of specifi c user actions and
results in rather sparse, but very clean importance measure for
our desktop resources. The second technique, published at
the Symposium on String Processing and Information Retrieval,
introduces a generalization concept according to which all
our desktop actions are relevant when ranking our personal
documents. While visibly more comprehensive, this latter algorithm
also includes some noise in its output, just because
some of our actions are driven by external factors, such as
context switches. We are thus planning to design, in 2007, an
even better desktop fi le ranking algorithm, which combines
the advantages of each of our current approaches.
Automatic Detection of Desktop Activity Contexts: Within our
second of investigation, we started again from activity analysis
as the main user profi ling information source. This was then
combined with an insight into the content of each fi le being
utilized, thus developing an exact approach to group personal
resources. Furthermore, we exemplifi ed this idea within a reallife
application, Web search: In this scenario, we fi rst looked
into each user’s desktop for documents relevant to her Web
query, and then exploited these to personalize the output of
the Web search engine. This turned out to be a very successful
technology, described in a paper presented at the ACM Conference
on Information and Knowledge Management.
Bringing Desktop Users Together: Finally, we also made the
fi rst steps towards building good inter-workspace relations.

Project Type: Integrated Project EU/IST FP6
Duration: 2006 – 2008
Research Areas: Desktop Search, Semantic Web,
Text and Data Mining, Social Networks.
Contact: Dipl.-Ing. Paul – Alexandru Chirita,
chirita@L3S.de
URL: http://nepomuk.semanticdesktop.org
More specifi cally, we proposed new approaches to identify
communities of users sharing similar interests. The techniques
we investigated were quite diverse, varying from data mining
algorithms on top of each user’s tags to analyzing the actual
contents of our neighbors’ desktops. Last, but not least, we
initiated another stream of research into workplace activity
support via content recommendations from social neighbors.
An interesting example here is the community wide identifi cation
of fi les, similar to a given item on our desktop. We expect
the fi rst full version of our social prototype results to be completely
functional by mid-2007.
SEMANTIC WEB AND DIGITAL LIBRARIES PROJECTS
info box
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
selected publications
Beagle++: Semantically Enhanced Searching and
Ranking on the Desktop. Paul - Alexandru Chirita,
Stefania Ghita, Wolfgang Nejdl, Raluca Paiu. In
Proceedings of the 3rd European Semantic Web
Conference (ESWC), Budva, Montenegro, 2006.
Analyzing User Behavior to Rank Desktop Items.
Paul – Alexandru Chirita, Wolfgang Nejdl. In Proceedings
of the 13th International Symposium
on String Processing and Information Retrieval
(SPIRE), Glasgow, United Kingdom, 2006.
Summarizing Local Context to Personalize Global
Web Search. Paul – Alexandru Chirita, Claudiu
Firan, Wolfgang Nejdl. In Proceedings of the 15th
ACM International CIKM Conference on Information
and Knowledge Management, Arlington,
United States, 2006.
49

50
SEMANTIC WEB AND DIGITAL LIBRARIES
REWERSE –
Reasoning on the Web with Rules and Semantics
In the last years the information technology community, and especially the web community, has employed
an increasing amount of Semantic Web technologies based on the emerging Web 2.0. Many
technologies and tools developed by the Semantic Web directly infl uenced a number of web-based applications
and systems currently being deployed. Semantic Web tools such as RSS, Ontologies and Taxonomies,
allow new intelligent search engines, automatic processing of content, complex transactions,
personalization, as well as content adaptation.
Challenges
The content on the semantic web is augmented with annotations
which describe the meaning of the data, and thus
support the automated processing of the data by machines.
These metadata (literally data about data) are the basis for
many applications that are currently leaving the test-beds and
starting to become main-stream tools on the web. Some examples
are RSS News Syndication or socially engineered community
web-sites. Socially engineered sites allow community
users to make annotations with free-form tags or by using
engineered Ontologies or Taxonomies.
REWERSE in particular aims at developing and standardizing
– in terms of an open W3C standard – a set of interoperable
rule languages for the Semantic Web, including such fi elds
as: e-commerce, e-contracting, authentication and authorization,
confl ict resolution, user profi le management, and personalization,
among many others.
summary
The objective of REWERSE is to establish
Europe as a leader for the Web by creating
a “Network of Excellence” among the
community that needs these tools and by
providing the basis for industrial software
development of advanced Web applications.
Education and Training as well as Technology
Transfer and Awareness are also part of
REWERSE.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
Project Type: Network of Excellence (NoE) funded
by the EU Commission and Switzerland within FP6
Duration: March 2004 – February 2008
Research Areas: Semantic-based knowledge systems
Contact: Prof. Dr. Nicola Henze, henze@L3S.de
URL: http://rewerse.net/
info box
L3S is leading the working group A3 which focuses on
“Personalized Information Systems”, one of the eight working
groups in the project.
In web-based information systems, personalization (or adaptation)
is used to change the content, the appearance,
the experience a user has when using the system, based on
implicit data about the user’s previous dealings with the system,
and the user’s preferences. These systems utilize a user
model, to model and store all the relevant information about
the user, and a personalization engine, powered by a variety
of techniques including rule-based fi ltering, to create the personalized
view. For sophisticated personalization approaches,
the sources of the information used must be annotated with
metadata of suffi cient quality; otherwise, the results of fi ltering
and adaptation become of limited use for end users.
R&D Highlights and Project Results
In the working group A3, L3S together with its partners, developed
a number of applications to use as test-beds and to
promote the potential of rule-based personalization for web
information systems. This includes the award-winning Personal
Publication Reader (3rd place at the Semantic Web Chal-

lenge Competition 2005), which is one of the applications
realized using the Personal Reader Framework developed by
L3S. Other published applications, developed at L3S are a Personalized
eLearning Reader for working with online eLearning
material, a Recommender and Syndication system for selecting
and listening to Music Streams, aka MyEar. Together with
the University of Torino, L3S developed a Curriculum Planner
System for the creation and validation of University Course
Curriculum Sequences, using the Hannover University course
database as information source. For creating metadata-rich
content, the working group A3 is also dealing with the automatic
extraction and aggregation of content from various
sources, e.g. the crawling of plain, but structured, web-pages
such as publication pages or a online course list, to create a
semantically rich and sound description of the content for use
with the personalized information systems.
L3S also participates in the working group I2 (policy specifi cation,
enforcement and integration), in which the Protune language,
an advanced Semantic Web policy language, has been
developed. Current achievements include the development of
an engine able to perform policy-driven negotiations and the
generation of natural language explanations from the result of
such negotiations. Current work focuses on the formulation of
policies based on natural language specifi cations, in order to
help users creating and understanding policies.
SEMANTIC WEB AND DIGITAL LIBRARIES PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
selected publications
F. Abel, I. Brunkhorst, N. Henze, D. Krause, K.
Mushtaq, P. Nasirifard and K. Tomaschewski: Personal
Reader Agent: Personalized Access to Confi
gurable Web Services. ABIS 2006 - 14th Workshop
on Adaptivity and User Modeling in Interactive
Systems, Hildesheim, October 9-11 2006
P. Barahona, F. Bry, E. Franconi, N. Henze, U. Sattler
(Eds.): Reasoning Web. Springer, 2006, ISBN
3-540-38409-X.
Nicola Henze and Daniel Krause: Personalized
Access to Web Services in the Semantic Web.
SWUI 2006 - 3rd International Semantic Web User
Interaction Workshop, November 6, 2006, Athens,
Georgia, USA, collocated with ISWC 2006
Piero A. Bonatti, Claudiu Duma, Norbert Fuchs,
Wolfgang Nejdl, Daniel Olmedilla, Joachim Peer,
and Nahid Shahmehri. Semantic web policies - a
discussion of requirements and research issues. In
3rd European Semantic Web Conference (ESWC),
volume 4011 of Lecture Notes in Computer Science,
Budva, Montenegro, June 2006. Springer.
51

52
SEMANTIC WEB AND DIGITAL LIBRARIES
VIKEF - Virtual Information and
Knowledge Environment Framework
Scientifi c and business documents contain information about relevant entities such as products or scientifi
c authors. If this knowledge is extracted and integrated from different sources, interesting services
become possible, which ease domain understanding. So far, however, considerable manual effort has to
be invested for making this knowledge explicit. The VIKEF project develops advanced methods for reducing
this effort and enables content and service providers such as trade fair and conference organizers to
build customizable intelligent services on top of the represented knowledge.
Challenges
The extraction of semantic information from a wide variety
of distributed scientifi c and business content, its adequate
representation and integration, as well as its effective re-use
in different application settings imposes major challenges for
the VIKEF project:
• automated information extraction methods: for extracting
entities and relationships from image, texts and semi-structured
information and for combining the extracted results;
• advanced information integration: for dealing with semantic
information extracted from different sources;
• seamless technology-level integration: for achieving full
knowledge supply chain support from raw content over semantic
representation to intelligent services;
• user-friendly customization support: for adapting the extraction
process to specifi c application content and for tailoring
intelligent services to community needs;
summary
The Semantic Web technology project VIKEF
is dedicated to multimedia information extraction
methods and to blossoming intelligent
services on top. In an intermediate
layer an advanced infrastructure for representing,
integrating and contextualizing
knowledge is built. VIKEF addresses trade
fairs and scientific conferences as crystallization
scenarios for the developed technology,
which is also applicable in other domains.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
info box
Project Type: Integrated Project funded by EU
Duration: April 2004 – March 2007
Research Areas: Information extraction,
Semantic Technologies, Personalization
Contact: Dr. Claudia Niederée, niederee@L3S.de
URL: http://www.vikef.net
R&D Highlights and Project Results
In the VIKEF project, methods and components for multimedia
information extraction, advanced knowledge representation
and integration, and personalized community services
are developed and integrated into a customizable framework
for supporting the full knowledge supply chain. In 2006, the
focus has been on improving the extraction pipeline, on developing
useful intelligent services on top of the knowledge
layer and on extending the customization support. Some of
the achieved outcomes are:
• Advanced solutions in personalization by considering relationship-based
user models and by realizing an approach for
cross-system personalization, which effectively re-uses user
information across system borders;
• An approach for using the extracted semantic information
for easing content digestion by “infusing” selected semantic
information into documents in a customizable way (semantic
infusion), e.g. by adding links to background knowledge and
high-lighting information.
• Improved support for information integration by contextualizing
knowledge and by introducing a systematic way of
managing entities and identities;

content
upload
machine
learning
content
harmonization
IMAGE
INFORMATION
EXTRACTION
customized
information
extraction
image
processing
Potential Applications
The technologies developed in VIKEF offer exploitable assets
for different application domains. Two application domains,
trade fairs and scientifi c conferences, have been investigated
in more detail during the project. In the trade fair domain,
VIKEF technology - especially the combination of semantic extraction
from text and image material – enables fair organizers
to deal more effectively with provider catalogues (e.g. supporting
catalogue merging). This enables fair visitors to easier
identify fi tting and similar products and to browse and search
uniformly across catalogue borders.
In the area of scientifi c conferences, VIKEF technologies enable
the provision of domain overviews and support organizers in
planning conference events. VIKEF domain overview services
help the conference participants and other community members
in understanding the domain and navigating among domain
resources enabling e.g. more effective event planning.
Further example applications are knowledge integration in
the automotive industry and the use of VIKEF extraction technology
for automating the creation of company ratings from
news articles.
SEMANTIC WEB AND DIGITAL LIBRARIES PROJECTS
LINGUISTIC
INFORMATION
EXTRACTION
annotation
pipeline
customization
multimedia
information
extraction
MULTIMEDIA
INFORMATION
EXTRACTION
ONTOLOGY
ENGINEERING
ontology
construction
support
ontology
learning
annotation
refinement
KNOWLEDGE
REPRESENTATION
semantic
elicitation
semantic
representation
information
integration
introducing
context
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
entity
management
semantic
navigation
services
intelligent
catalogue
services
semantic
infusion
SMART
COMMUNITY
SERVICES
knowledge
view
definition
selected publications
Stecher, Rodolfo; Niederée, Claudia; Bouquet,
Paolo, Jacquin, Thierry; Ait-Mokhtar, Salah; Brunelli,
Roberto and Demetriou, George: Enabling a
Knowledge Supply Chain: From Content Resources
to Ontologies : ESWC 2006 Workshop on Mastering
the Gap: From Information Extraction to Semantic
Representation
Dietz, Laura; Stewart, Avaré: Utilize Probabilistic
Topic Models to Enrich Knowledge Bases. : ESWC
2006 Workshop on Mastering the Gap: From Information
Extraction to Semantic Representation
53

54
SEMANTIC WEB AND DIGITAL LIBRARIES
PSW – Personalization in the Semantic Web
The vision of the Semantic Web is to enable machines to process the meaning of electronic Web resources.
Basic techniques for the Semantic Web have been developed so far, and the Semantic Web becomes
more and more popular and starts to grow. However, one of the most important questions is still open:
how to match – semantically enriched – information to the needs of the end user? Personalized systems
exactly cope with this problem by fi rst learning what kind of information is relevant for the user, and
second how to discover, prepare and present this information.
Personalization
Personalization, the task of adapting interfaces, behavior and
content of an application to a user has been implemented
in a variety of applications. Personalized systems recommend
which items we should consider to buy, show menu items
which are relevant to fulfi ll our current task, give us hints what
we might consider to explore next, and so on. Many different
techniques, like recommender systems or adaptive hypermedia
systems, have been proposed for realizing personalization
in different scenarios and applications.
Personalization in the Semantic Web
The challenge of applying personalization in the Semantic
Web is to take the special characteristic of the Semantic Web
summary
This project aims at realizing personalized
access to Semantic Web content. Personalization
rules are defined which search,
access and syndicate information in the Semantic
Web according to the individual requirements
of the end user. A user interface
supports users to configure and combine
personalization rules as they like. The enabling
infrastructure is based on a Semantic
Web service architecture and demonstrates
a maximum flexibility for realizing personalized
information access.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
info box
Project type: Research project funded by the DFG
Duration: May 2006 – April 2008
Research areas: Information discovery, Semantic
Web, Personalization, Rules
Prof. Dr. Nicola Henze, henze@L3S.de
M. Sc. Daniel Krause, krause@L3S.de
http://www.personal-reader.de
into account: distributed data, and domain independence.
Everybody is invited to contribute resource to the Semantic
Web by publishing on any webserver in the world, and by
annotating the content independently from other authors.
Hence, personalization has to cope in this area with the problems
of fi nding relevant resources, combining differently annotated
resources from different sources, and the fact that the
discovered information might even be incomplete.
Rule based systems are a very promising approach in this area.
They have been researched for a long time in artifi cial intelligence,
can handle incomplete data, and are very well suited
for reasoning on information about the user and the user requirements.
Challenges
The goals of the PSW project are divided into four main
tasks:
• Formal classifi cation of methods for personalization
in the Semantic Web: Which personalization methods and
techniques are adequate for the Semantic Web? Which stateof-the-art
methods for personalization are less suited for being
used in the Semantic Web?

• Personalization rules and rule patterns: What do personalization
rules look like, how can they be modeled? Do rule
patterns exist, i.e. patterns that can be used to generate rules
for different domains or tasks automatically?
• User interface: How can users confi gure personalization
rules according to their needs and how can they correct automatically
generated rules? How can users combine rules to
generate new, more complex and expressive rules?
• Infrastructure: How can such an interface be integrated
into a personalized information system for the Semantic Web?
How can personalization modules which are reused in different
applications be designed?
The Personal Reader Framework
The Personal Reader Framework - a Semantic Web Servicebased
framework for designing, implementing and realizing
personalized Web Content reader – is used for a prototypical
implementation. Here, so-called personalization services encapsulate
parameterized personalization rules. Other Semantic
Web Services, so-called Syndication Services, create user
interfaces and support users discover, adjust and combine
personalization rules.
SEMANTIC WEB AND DIGITAL LIBRARIES PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
selected publications
Nicola Henze and Daniel Krause: Personalized
Access to Web Services in the Semantic Web.
SWUI 2006 - 3rd International Semantic Web User
Interaction Workshop, November 6, 2006, Athens,
Georgia, USA, collocated with ISWC 2006
Nicola Henze and Daniel Krause: User Profi ling and
Privacy Protection for a Web Service Oriented Semantic
Web. ABIS 2006 - 14th Workshop on Adaptivity
and User Modeling in Interactive Systems,
Hildesheim, October 9-11 2006.
55

56
SEMANTIC WEB AND DIGITAL LIBRARIES
KnowledgeWeb – Moving the Semantic Web from
Academia to Industry
A major problem of today’s information society is the huge amount of data, e.g., in the World Wide Web,
which can only be processed with sophisticated technologies such as those used by today’s search engines.
Computers, however, cannot understand the meaning or “semantics” of such data without further
help. For example, the semantics of “Jaguar” (e.g., an animal vs. a car) remains unclear by just looking
at the word “Jaguar”. Since 1991, researchers have proposed to extend the Web with semantics, to create
the “Semantic Web”, but industry has only recently started to adopt these ideas. KnowledgeWeb is
intended to support this transition process from the university into industry.
Challenges
The Semantic Web is an extension of the current World Wide
Web, where textual data is extended with metadata carrying
the necessary semantics to enable machines to understand
the Web data. Transferring such Semantic Web technologies
from research into industry will enable the integration of extended
and intelligent functionalities for the Next Generation
Web, to improve the retrieval and re-use of information on
the Internet, company intranets as well as on every desktop.
KnowledgeWeb follows a three-pillar approach to support
such transition process:
• Outreach to industry: Promote greater awareness and faster
take-up of Semantic Web technology within Europe in full
synergy with the research activity. As researchers have often
only a vague idea of industrial requirements, this will help to
reduce time needed to transfer the technology to industry
and to market.
• Outreach to education: Establish a European Association
for Semantic Web Education (EASE), acting as a hub for all
educational activities related to Semantic Web topics. Such
a single contact point with high-class educational resources
is essential for companies to be able to educate their staff in
Semantic Web technologies.
• Coordination of research: Ensure that the research is suffi
ciently coordinated to avoid both duplication and fragmentation.
Since the Semantic Web is an inter-disciplinary area,
such coordination is particularly important and requires joint
collaborations among and across various research communities.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
summary
The Semantic Web is an extension of the
World Wide Web designed to provide machines
working on World Wide Web data
with additional information about the meaning
of that data. KnowledgeWeb brings
together the work of eighteen first-class
research institutes from all over Europe to
support the deployment of Semantic Web
technologies from academic environments
to industrial settings.
R&D Highlights and Project Results
The L3S Research Center is leading the ‘Outreach to education’
pillar of the KnowledgeWeb, whose main idea is that
the Semantic Web can only become a success story if enough
industrial people have been educated in Semantic Web technologies
to be able to use such technologies. In collaboration
with its partners, L3S has provided a comprehensive Semantic
Web Educational Portal, the so-called REASE Repository
(http://rease.semanticweb.org). The repository allows the
publication of educational material related to Semantic Web
topics under a single infrastructure, providing e.g., customizable
licenses and a metadata-based search. At the end of
2005 we started with 140 registered users, from more than
70 different institutions. Now we have more than 350 users
from 170 institutions all over the world. They have access to
more than 100 high-quality learning units about Semantic
Web topics, comprising teaching materials and best practice
examples, as well as the necessary information about back-

ground technology. More than 30 of these units have been
especially designed for industrial education purposes to support
the transition process of Semantic Web technology from
research to industry.
Furthermore, in June 2006 L3S spearheaded the foundation
EASE, the “European Association for Semantic Web Education”.
EASE is intended to support following:
• eLearning activities related to Semantic Web throughout Europe
and the necessary infrastructure to host the Educational
Portal
Project Type: Network of Excellence funded by EU
Duration: January 2004 – December 2007
Research Areas: Semantic Web Technologies, Education,
Ontologies
URL: http://knowledgeweb.semanticweb.org
http://rease.semanticweb.org
Contact: Dr.-Ing. Jörg Diederich,
diederich@L3S.de
SEMANTIC WEB AND DIGITAL LIBRARIES PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
• educational events such as the KnowledgeWeb summer
school
• the integration of European Higher Education efforts, manifested
in a joint European Master program in Semantic Web
and Ontology technology.
EASE will ensure that the educational activities in KnowledgeWeb
will endure even after the end of the project.
selected publications
info box J. Diederich and W. Nejdl and R. Tolksdorf: EASE:
The European Association for Semantic Web Education,
in Proceedings of the Semantic Web Education
and Training Workshop (SWET‘06), co-located
with the First Asian Semantic Web Conference
(ASWC 2006), Beijing, China, September 2006.
W.-T. Balke and U. Thaden and J. Diederich: The
Semantic GrowBag Demonstrator for Automatically
Organizing Topic Facets, in Proceedings of the
SIGIR2006 Workshop on Faceted Search, Seattle,
USA, August 2006.
57

58
SEMANTIC WEB AND DIGITAL LIBRARIES
iSearch – Satisfying Your Information Needs
The ever increasing size of the World Wide Web has made search engines part of our everyday lives. And
yet, although usually indispensable for fi nding information across the Web, search technology is fairly
young and underdeveloped. Many of its areas have not yet seen a viable architectural solution. User
personalization, spam detection, and advertising are only a few of these. Within iSearch, L3S designs
advanced algorithms to bring these areas further on their way towards technological maturity.
2006 Challenges Overview
Search can be improved in many ways and iSearch took a
systematic approach to tackle the particular limitations of
Web Information Retrieval. Within 2006, we focused on three
highly important challenges. First, there is the pressing problem
of malicious Internet content, which strongly impedes
search engine users in fi nding web pages relevant to their information
needs. Second, we investigated the technological
demand for better and faster reputation ranking algorithms
across the World Wide Web. Finally, we discovered that these
ideas could be strategically exploited in other application domains
as well, thus further easing the working and search experience
of each person.
R&D Highlights and Results
Web Spam Detection: Our work towards the challenge of Web
spam detection marked an important progress within the
research community, and was published at the World Wide
Web Conference. We proposed to analyze hyperlink relationships
at the macroscopic level of Web sites, rather than simple
pages. As a result, we were able to identify a large number
of entities (e.g., companies, groups of users, etc.) participating
in various types of the so-called link farms in an attempt
to subvert the ranking system, and consequently to promote
themselves artifi cially towards the top of the search engine
results lists.
Effective Social Ranking for the Web: In the year 2006, the L3S
Research team developed the idea of applying mathematical
optimizations to the distributed computation of power-law
based social ranking algorithms, in particular that of Google’s
PageRank. While these improvements were already widely
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
summary
Year 2006 research results developed within
iSearch have set high standards for the next
year, the fourth of this German funded project.
We managed to refine several significant
ideas and presented them in the context
of top research conferences in the area
of information and internet technologies,
including new and highly important Web
site level spam detection technique. We look
forward to facing new and innovative challenges
in the year 2007, further improving
the quality and user experiences in searching
Web and other large collections.
employed within the slow, centralized implementations of the
well-known ranking algorithm, they were thought to be impossible
to apply within a distributed setting. This is where
our ideas came in and rendered the effi cient parallel implementation
possible, thus speeding PageRank considerably. As
this solution was also welcomed by the search engine experts,
our report describing it was published within the European
Conference on Information Retrieval.
Integration with Other Domains: Within our third research
stream, we attempted to bring the World Wide Web research
closer to the community of Personal Information Management,
which studies technological advances for PC Desktops.
As this idea was generally unexplored, we developed several

innovations, an important one being the Web page oriented
Task Management Support. Our contribution in this area was
to extract informative keywords from the local document currently
edited / viewed by the user (e.g., Word, PDF, etc.), and
to use them in order to search the Web for other pages, highly
relevant to user’s fi le. In this way, valuable Web input is automatically
recommended to the Desktop user within a nonintrusive
application.
Project Type: Local Government Funding
Duration: 2004 – 2009
Research Areas: Web / Desktop / Enterprise
Search, Personalization, Link Analysis, Text and
Data Mining
Contact: Dipl.-Ing. Paul – Alexandru Chirita,
chirita@L3S.de
URL: http://www.L3S.de/iSearch
SEMANTIC WEB AND DIGITAL LIBRARIES PROJECTS
info box
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
selected publications
1. Site Level Noise Removal for Search Engines.
Andre Carvalho, Paul – Alexandru Chirita, Edleno
Silva de Moura, Pavel Calado, Wolfgang Nejdl. In
Proceedings of the 15th International World Wide
Web Conference (WWW), Edinburgh, United Kingdom.
2. Effi cient Parallel Computation of PageRank.
Christian Kohlschütter, Paul – Alexandru Chirita,
Wolfgang Nejdl. In Proceedings of the 28th European
Conference on Information Retrieval (ECIR),
London, United Kingdom.
3. Pushing Task Relevant Web Links down to the
Desktop. Paul – Alexandru Chirita, Claudiu Firan,
Wolfgang Nejdl. In Proceedings of the 8th ACM
Workshop on Web Information and Data Management
(WIDM - 21% acceptance rate on full papers)
held at the 15th ACM International CIKM Conference
on Information and Knowledge Management,
Arlington, United States.
59

60
PROJECTS TECHNOLOGY DISTRIBUTED SYSTEMS ENHANCED AND LEARNING NETWORKS
PEERTRUST – Negotiating Trust on the Web
Nowadays, the Web poses serious security and privacy concerns due to the potential implications of
information misuse. Users are permanently under the threat of attackers trying to get access to information
they are not authorized to receive. A main problem is that authorization on the Web is unidirectional
and based on identities (though many transactions occur among strangers). The former requires
that only web servers can state conditions that clients must fulfi ll in a take-it-or-leave it fashion. The
latter obliges users to trust web servers simply by knowing their identity from a certifi cate.
Authorization based on properties
The Web, with its enormous amount of users as well as web
servers, is expanding rapidly. Traditional authorization relies
on the fact that any two entities are able to make an authorization
decision solely with the information of each other’s
identities. However, this assumes that both entities are known
to each other in advance. Since on the Web any two strangers
must be able to interact, a new authorization scheme based
on properties has emerged (e.g., whether a requester is a student
or employee of a company). Those properties can be
proven via disclosure of credentials: the digital equivalent to
our real life student cards, passports or driver licenses.
Using policies to state conditions
Users and web servers can now use statements describing the
conditions under which access to their resources or information
can be gained. Whether a requester is a European citizen
or a member of the Better Business Bureau seal program are
examples of those conditions that may be used to control who
has access to what. As part of this project, two different policy
languages with different levels of complexity and expressiveness
have been developed: PeerTrust and Protune. Both of
them allow for advanced specifi cations of conditions that
other parties must satisfy before information is disclosed.
Bilateral Negotiations
Due to the fact any entity can now specify conditions under
which their resources and information are disclosed, transactions
no longer are a one-shot interaction, but a bilateral
negotiation. Entities negotiate based on their policies and increase
the level of trust after each iteration. Disclosure of credentials
may help to satisfy the other party‘s policy and there-
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
fore advance forward towards a successful negotiation. These
negotiations are not only driven by each party‘s policies, but
also by their negotiation strategies. A negotiation strategy defi
nes which option to take in case alternatives exist.
Policy Specification and User Awareness
This new authorization schema puts responsibility on the user
side. Users should specify their policies which will be used as a
basis for negotiation. A trade-off between the expressiveness
of the language and its simplicity is therefore required. In the
PeerTrust project, we identify and address two different target
groups: policy developers and users. Policy developers require
good knowledge and understanding of the formal semantics
of the policies as well as specifi cation and validation tools.
Users will then instantiate and personalize templates and default
policies made by developers but still require explanations
and translations into natural language.
info box
Project type: Internal
Duration: September 2003 - December 2008
Research Areas: Policies, Security, Trust,
Privacy, Reasoning, Rules
URL: http://www.L3S.de/peertrust/
Contact: Daniel Olmedilla, olmedilla@L3S.de

DISTRIBUTED SYSTEMS AND NETWORKS PROJECTS
selected publications
Piero A. Bonatti, Daniel Olmedilla, and Joachim
Peer. Advanced policy explanations on the web. In
17th European Conference on Artifi cial Intelligence
(ECAI 2006), pages 200-204, Riva del Garda, Italy,
Aug-Sep 2006. IOS Press.
Piero A. Bonatti and Daniel Olmedilla. Semantic
web policies: Where are we and what is still missing?
Tutorials at the European Semantic Web
Conference (ESWC), June 2006, and 2nd RuleML
International Conference, November 2006.
Grigoris Antoniou, Matteo Baldoni, Piero A.
Bonatti, Wolfgang Nejdl, and Daniel Olmedilla.
Rule-based policy specifi cation. In Ting Yu and
Sushil Jajodia, editors, Secure Data Management in
Decentralized Systems, volume 33 of Advances in
Information Security. Springer, 2007.
summary
Current Web requires that any two strangers
must be able to interact but traditional
authorization based on identities does not
scale. A new scheme based on properties
and negotiations transforms authorization
on the Web into a bilateral and secure process
in which trust is built iteratively based
each entity‘s policies. In order to ensure
its adoption, current research must focus
on the user, who must be able to use and
understand her policies without requiring
technical knowledge.
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D-Grid Integration Project –
Building the Infrastructure for eScience
The modern knowledge and information society is affected by various possibilities of communication
and simple access to information services, data storages and high capability computing resources. Relating
to research activities these techniques enlarge the potential for better qualitative and quantitative
scientifi c results. However, the challenge to maintain and provide the resources in such heterogeneous
and distributed infrastructures increases with the complexity of the system components.
Grid Computing – doing eScience
The concept of Grid systems lies in the virtualization of computing
and storage infrastructures by hiding the details of the
implementation. The user only needs to know how to access
the offered services; knowledge about their location becomes
unimportant.
The collaborative nature of Grids enables researchers to use
new methods and procedures in science and industry. Grids
support the creation of „Virtual Organizations“, dynamic aggregations
of resources and users, to enable geographically
dispersed collaborations of researchers. In the era of eScience,
Grids act as the key technology. Researchers, supported by resource
providers, develop and standardize Grid infrastructures
which will become the mainstream in daily scientifi c work.
To realize the vision of eScience in the German scientifi c community,
six community grid projects were started in September
2005. By funding distinct areas of research, the risk of producing
isolated Grids which do not share tools and resources
was obvious. Therefore, an additional integration project was
established to provide a common foundation for the D-Grid
initiative.
Areas of work
Researchers at L3S participate in the integration project in the
fi elds of monitoring, accounting and billing (MAB), transport
protocols, authentication and authorization infrastructures
(AAI). Additionally, L3S participates in developing new concepts
for the use of fi rewalls and provide the dedicated D-Grid
infrastructure.
MAB
The MAB section provides concepts and components for visualizing
the state and usage of Grid resources. The monitoring
infrastructure displays the current state of Grid resources and
FORSCHUNGSZENTRUM FORSCHUNGSZENTRUM L3S L3S · · L3S L3S RESEARCH RESEARCH CENTER CENTER
currently processed jobs. The accounting data builds the basis
for the billing section. Therefore, the sections: monitoring,
accounting and billing act together to satisfy the needs for a
sustainable operation of the D-Grid infrastructure. Activities
from the L3S comprise the coordination of MAB as well as
research in the sections accounting and billing.
AAI
While access to the D-Grid infrastructure shall be free for all
community members, the identity of the accessing party has
to be proofed by strong authentication mechanisms. After the
successful authentication the user wants to perform certain
tasks on the Grid he is authorized to do. These mechanisms
are essential in distributed computing architecture. In D-Grid,
the AAI project aims to defi ne and introduce a common authentication
and authorization infrastructure for all three supported
Grid middleware.
summary
To bring the vision of eScience in Germany
to reality, the creation of a robust, flexible
and sustainable Grid infrastructure is
needed, which consists of network, computing
and storage resources as well as of Grid
services and middleware layers. The D-Grid
Integration Project, as part of the D-Grid
consortium, integrates developments from
different community projects in one common
D-Grid platform. This platform will be
offered as services to the entire German
scientific community.

Firewalls
Firewalls control the communication patterns across institutes.
Their presence is fundamental but their confi guration tends to
be cumbersome. Systematic research and analysis have been
carried out to identify the communication channels required
by Grid services and to devise a recommended installation for
the D-Grid Integration Project. The impact of Grid services on
fi rewall confi gurations has been asserted and less invasive deployment
models have been proposed. Current results have
been shared with international partners and included in the
latest documents of the Open Grid Forum.
Success leads to more funding
Due to the convincing results of D-Grid, hardware for a dedicated
D-Grid infrastructure was funded at the end of 2006.
These resources are spread over more than 25 locations and
comprise more than 2,100 CPU cores and about 5 petabytes
of storage.
In addition to the ongoing projects new scientifi c communities
and gap projects to address open issues in Grid middleware
were initiated. The fi rst funded gap project called IVOM
deals with the interoperability of Shibboleth and the management
of Virtual Organizations. IVOM was jointly proposed by
members of L3S and Community Grids.
DISTRIBUTED SYSTEMS AND NETWORKS PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
info box
Project Type: D-Grid Integration Project,
funded by BMBF
Duration: September 2005 – February 2008
Research Areas: Distributed Research
Environments, Grid Computing
Contact: Prof. Dr.-Ing. Gabriele von Voigt,
Prof. Dr.-Ing. Christian Grimm,
{vonvoigt, grimm}@L3S.de
http://www.d-grid.de/
selected publications
S. Piger, C. Grimm, J. Wiebelitz, R. Gröper: An
Approach to Restricted Delegation of User Rights
based on the gLite Middleware, Proc. Cracow Grid
Workshop 06, Cracow, Poland, October 2006
R. Niederberger, W. Allcock, G. L. Volpato, C.
Grimm, et. al.: Firewall Issues Overview, Open Grid
Forum Document GFD.83, August 2006
C.-P. Rückemann, W. Müller, G. von Voigt: Comparison
of Grid Accounting Concepts for D-Grid,
Proc. Cracow Grid Workshop 06, Cracow, Poland,
October 2006
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PROJECTS TECHNOLOGY DISTRIBUTED SYSTEMS ENHANCED AND LEARNING NETWORKS
UKoLoS – Ultra-wideband Radio Technologies for
Communications, Localization and Sensor Applications
Radio technology has been widely used throughout recent decades. The increasing number of radio systems
and services has enforced administrative regulation organizations to divide the electromagnetical
spectrum in narrow bands to enable rapid development and low interference coexistence of applications.
Ultra-Wideband (UWB) radio systems follow a novel approach, where basically the whole frequency
range from about 100MHz to beyond 10GHz can be used. To ensure coexistence regularisation efforts
over the world protect established narrow-band systems by allowing only very low UWB power densities.
The priority programme UKoLoS focuses on the investigation of basic UWB technology for new and innovative
application areas, especially in the fi eld of sensors and electronic measurements.
Challenges
UKoLoS is a priority program composed of several projects.
L3S works within the project PAOLA (Design of Power Aware
Scheduling schemes for Low Power and Low Data Rate Ultra-Wideband
Networks) whose research interest focus on the
application of UWB technology in sensor networks for industrial
and logistics applications. The aim of PAOLA is the design
of medium access control (MAC) protocols enabling effi cient
and low-power communications. Major challenges addressed
are:
• Maximization of the overall lifetime of the network, while
trying to maximize the data rate offered to each node. Here,
there is a need to understand the design trade-offs in low
power and low rate operation
• design of a link scheduling function, which handles interference
by controlling the time when a packet is transmitted
• design of a power management scheme which controls the
devices sleep/active cycles
R&D Highlights and Project Results
Requirements imposed by systems with joint communication
and positioning/locating functionality, appearing e.g. in industrial
environments and logistic applications, suggest that
the MAC layer shall dynamically trade system performance
with power consumption for the devices. The goal of PAOLA
to fi nd out which advantages does the use of additional information
such as location, mobility state or residual battery
energy have in the link scheduling and in the power-saving
algorithms for a low power low data rate UWB network. Derived
analytical results will be the basis for investigation of the
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
optimal scheduling and power-saving algorithms in realistic
scenarios. The combination of both functions shall control
the transmission of each node to optimize the network lifetime
while keeping network throughput high. Some of the
achieved outcomes are:
• Defi nition of the system model at the physical layer, since
physical layer awareness is a requirement to enhance the design
of MAC protocols in UWB
• Initial defi nition of a transmission control function, which
controls the transmission probability of sensor nodes trying
to communicate with a base station in a factory scenario (so
called “reader” scenario)
• Initial design of an activity management algorithm, which
controls the sleep/ active periods of the sensor nodes
summary
The Ultra-Wideband priority program, UKo-
LoS, is dedicated to improving and investigating
the application of Ultra-Wideband
Radio Systems for Localization, Communications
and Sensor Applications in Europe.

Potential Applications
The UWB radio technology offers a complementary approach
to existing wireless technologies enabling many novel applications,
especially in the fi elds of communications, localization
and sensor measurements. Due to its huge bandwidth, UWB
allows for high temporal and spatial resolution of sensors and
localisation systems without ambiguities. Regarding sensor
applications, UWB sensors can obtain much more information
about material properties and structures of scanned media or
bodies. In radio communications, high data rates can be transmitted
over short distances or, alternatively, low data rates can
be sent over longer distances with high energy effi ciency.
DISTRIBUTED SYSTEMS AND NETWORKS PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
info box
Project Type: Research priority program funded
by DFG (German Research Foundation)
Duration: June 2006 – June 2008
Research Areas: Ultra-Wideband Radio Technology
and its Applications
Contact: Dipl.-Ing. M. Dolores Pérez Guirao,
lola@L3S.de
URL: http://www.emt.tu-ilmenau.de/ukolos/
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PROJECTS TECHNOLOGY DISTRIBUTED SYSTEMS ENHANCED AND LEARNING NETWORKS
PULSERS PHASE II – Pervasive Ultra-wideband Low
Spectral Energy Radio Systems Phase II
Traditionally, the development of wireless communications applications has been driven by the need to
effi ciently use the spectrum resources, which are scarce. Worldwide, regulative authorities are in charge
of releasing the utilization of the scarce and extreme valuable spectrum resources. Ultra-Wideband
(UWB) radio technology follows a novel approach, based on sharing already occupied spectrum resources
by means of the overlay principle, rather than looking for still available but possible unsuitable
new bands. Novel devices and systems based on this emerging radio technology have the potential to
provide solutions for many of today’s problems in the areas of spectrum management and radio system
engineering. The PULSERS Phase II project investigates the challenges and possibilities associated with
the Ultra-Wideband (UWB) technology and its application in Europe.
Challenges
PULSERS Phase II is an extensive project composed of several
working packages. L3S works within the working package
Wp3b, whose research interest focus on the application of
UWB technology in sensor networks for industrial and logistics
applications. The aim of Wp3b is the design and demonstration
of a system that allows the autonomous deployment
and operation of (groups) of UWB devices with highly fl exible
communication and positioning/location functionality. Major
challenges addressed are:
• enhancement of location information obtained via UWB by
fusion with an integrated low cost inertial navigation system;
• design of an autonomous resource access scheme at the
medium access control (MAC) layer for the communication of
autonomous aggregates of UWB devices;
• design of radio frequency (RF) subsystem, which should
provide bi-directional data communication functionality as
well as localization functionality, by means of time-of-arrival
measurements;
R&D Highlights and Project Results
Systems with joint communication and positioning/locating
functionality, appearing e.g. in industrial environments and
logistic applications, necessitate a high degree of confi gurability
and the availability to operate in uncoordinated environments.
Algorithms and components in the area of radio
frequency and baseband processing, networking and medium
access control, and positioning and tracking are developed
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
summary
The Ultra-Wideband technology project,
PULSERS, is dedicated to improving and
investigating the application of Ultra-Wideband
Radio Systems for Localization & Communications
in Europe.
and integrated into a system demonstrator. In the year 2006,
the focus of the R&D activities has been on the defi nition of
the Wp3b subsystems requirements and establishment of the
initial system design. Some of the achieved outcomes are:
• Defi nition of a resource access scheme which should avoid
the breakdown of the resource (channel capacity) by applying
strategies acting on the pulse rate and the modulation
scheme of the transmitted signals;
• Proposal of a novel routing protocol consisting of an enhanced
“energy-aware” version of the Greedy Perimeter
Stateless Routing (GPSR), a location-based reactive multi-hop
protocol;
• Defi nition of the RF subsystem requirements. It should provide
bi-directional data communication functionality as well as
localization functionality, supporting two-way-ranging (TWR)
as well as Differential-TDOA. The RF part will be a multi-chip
solution including an interface to the baseband processor.
The transmitter concept is based on an impulse generator
supporting pulse amplitude as well as pulse position modula-

tion. The receiver concept is a non-coherent impulse detector
including high-speed time measurement functionality.
• Defi nition of the requirements of the UWB positioning system;
specifi cation of its main subsystems and components.
Potential Applications
The UWB radio technology offers a complementary approach
to existing wireless technologies enabling additional features
(accurate localization and tracking) and applications. Two
main application domains, short range high speed communications
and long to medium range, low data rate joint communication
and positioning applications are investigated in
detail during the PULSERS Phase II project. Wp3b focuses on
the second application domain, i.e. low data rate joint communication
and positioning applications. Here UWB technology
- especially impulse radio (IR) UWB- enables the uncoordinated
operation of groups of radio devices in industrial
environments and logistic applications, ensuring robustness
against unpredictable interference either coming from alien
or the same system.
DISTRIBUTED SYSTEMS AND NETWORKS PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
info box
Project Type: Integrated Project funded by EU
Duration: January 2006 – June 2008
Research Areas: Ultra-Wideband Radio Technology
and its Applications
Contact: Dipl.-Ing. M. Dolores Pérez Guirao,
lola@L3S.de
URL: http://www.pulsers.info
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PROJECTS TECHNOLOGY DISTRIBUTED SYSTEMS ENHANCED AND LEARNING NETWORKS
Autonomous Forklift Truck – Variable Pallet Pick-up
and 3D Localization in Industrial Environments
A cooperation between the company STILL GmbH and the L3S/Institute for Systems Engineering of the
University of Hannover was set up with the objective of developing an autonomous forklift truck to facilitate
fl exible navigation and material handling. The forklift trucks developed are able to recognize and
lift pallets, as well as move them to another location autonomously.
State of the art
Internal material fl ows are an area which can could be greatly
improved in many companies and attempts to fi nd more costeffective
and fl exible systems are very common. Depending
on the application, a range of systems are used for material
fl ows. Some example systems are: static systems dealing with
a high level of transport and fi xed transport routes; driverless
transport systems dealing with medium to high levels of
transport and alternating transport routes using simple predefi
ned material handling; and conventional forklift trucks
which are used in almost every company for complex material
handling due to its varied areas of utilization. Although driverless
transport systems have been used to automate processes
since the 1960s, the utilization of these systems is greatly restricted
when compared to conventional forklift trucks with
human drivers.
Project approach
In order to improve the situation, a cooperation between the
company STILL GmbH and the L3S/ Institute for Systems Engineering
of the Leibniz University Hannover was set up with
the objective of developing an autonomous forklift truck to
facilitate fl exible navigation and material handling. The forklift
truck developed is able to recognize and lift pallets, as well as
move them to another location autonomously.
Results of research and development
The main innovation of the forklift truck is the fact that the
pallets must no longer be positioned within predetermined
pick-up locations, measured exactly to the last centimeter.
Instead, the pallets can be lifted from different positions and
heights autonomously. In order to allow automatic movement
of the reach truck, it must be capable of locating itself in
the environment. A 2D localization and a 3D localization are
FORSCHUNGSZENTRUM FORSCHUNGSZENTRUM L3S L3S · · L3S L3S RESEARCH RESEARCH CENTER CENTER
summary
The forklift truck enables the identification
of pallets, picking them up and automatically
putting them down again in another
place. The essential innovation of the system
is that the pallets do not have to be put at
a pre-defined hand over point, but instead
are picked up flexibly from varying positions
and heights. A further significant innovation
can be found in the localization equipment.
The 3D ceiling localization system enables
navigation in a highly changeable environment.
implemented for the localization, which does not require any
alteration or modifi cation to the environment, as for example,
the installation of refl ectors. The 2D localization utilizes the
sensor information from the 2D laser scanner mounted on
the forklift truck to determine its position. The actual position
of the fork-lift truck is established on a previously prepared
environmental map. Alternative to the 2D localization, the
L3S/ Institute for Systems Engineering utilize a 3D localization,
with the assistance of a 3D laser scanner specially developed
for navigational tasks. The 3D laser used to establish
the position of the forklift truck is by way of the ceiling
structure of the building. The ceiling structure is perceived as
three dimensional by the 3D laser scanner and with a previously
prepared ceiling map, the actual position of the forklift
truck is determined. The localization by way of the ceiling
structure provides a reliable navigation procedure, because
normally, the ceiling structure does not change within an
industrial environment even over a long period of time and

Project Type: Industrial Project
Research Areas: Autonomous mobile robots, 3D-
Perception, Industrial Automation
Prof. Dr.-Ing. Bernardo Wagner (wagner@L3S.de)
Dipl.-Ing. Daniel Lecking (lecking@L3S.de)
URL: http://www.rts.uni-hannover.de/index.php/
Autonomer_Gabelstapler
changes in the rest of the environment, such as remodeling of
the shelving system, partition walls etc, do not infl uence the
localization. Independently of these autonomous capabilities,
the forklift truck keeps all its in-series features that make dualuse
possible.
Presentations
The functional effi ciency of the forklift truck was demonstrated
at the STILL GmbH stand at CeMAT 2005 fair in Hannover
from 11th to 15th October 2005. The fl exibility of lifting palettes
from the fl oor and platform, as well as free navigation
with the assistance of the ceiling characteristics was demon-
DISTRIBUTED SYSTEMS AND NETWORKS PROJECTS
info box
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
selected publications
Wulf, O.; Lecking, D.; Wagner, B.: Robust Self-Localization
in Industrial Environments based on 3D
Ceiling Structures, IEEE/RSJ International Conference
on Intelligent Robots and Systems (IROS),
October 9-15, 2006, Beijing, China.
Lecking, D.; Wulf, O.; Wagner, B.: Variable Pallet
Pick-Up for Automatic Guided Vehicles in Industrial
Environments, 11th IEEE International Conference
on Emerging Technologies and Factory Automation,
September 20-22, 2006, Prague, Czech
Republic.
Lecking D.; Wulf O.; Viereck, V.; Toedter J.; Wagner
B.: The RTS-STILL Robotic Fork-Lift: Variable pallet
pick-up and 3D localisation in industrial environments,
The Third EURON/EUnited Robotics Technology
Transfer Award, March 18, 2006, Palermo,
Italy.
strated. Moreover, the forklift truck achieved an award at the
EURON Technology Transfer Award 2006 in Palermo. The
EURON/erf Technology Transfer Award rewards outstanding
innovations in robot technology and automation arising from
cooperation between academic researchers and industry.
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PROJECTS TECHNOLOGY DISTRIBUTED SYSTEMS ENHANCED AND LEARNING NETWORKS
Trobot – Electronic drawbar for unmanned ground
vehicles
In May 2006 the German Federal Armed Forces conducted the 1st European Land-Robot Trial (ELROB)
2006 in Hammelburg, Germany. The scope of this event was to provide an overview of the European
state-of-the-art in the fi eld of unmanned ground vehicles (UGVs). Rheinmetall Landsysteme GmbH, a
German supplier for military ground vehicles, and the L3S/ Institute for Systems Engineering at the Leibniz
University Hannover used the ELROB 2006 to present their capabilities in the fi eld of autonomous
vehicles.
Project Approach
Transportation and logistics are two essential future fi elds of
application for autonomous mobile robots in military context.
These autonomous systems can help to reduce the endangerment
of soldiers in confl ict areas.
On behalf of Rheinmetall Landsysteme GmbH, the Institute
for Systems Engineering developed a so-called electronic
drawbar. This function enables unmanned ground vehicles to
automatically follow a person or another vehicle in selectable
distances. Differing from common approaches, data communication
is not required between leader and follower. The key
component of this system is the automatic leader’s recognition,
based on 3D laser scans and camera images. Deduced
from these data the leader’s position is computed and the
motion of the leading person or vehicle is predicted. Based on
the predicted position and motion, a vehicle controller is able
to compute the vehicle’s speed and steering commands for
following the path of the leading person or vehicle by maintaining
the selected distance. In addition to following the
leaders’ footsteps, this electronic drawbar is also useable for
guiding the follower backwards. Controllable like a car trailer,
this function can e.g. be used for backing into a parking
space. As the electronic drawbar is based on optical sensors,
a direct line of sight between leader and follower is required.
Disturbing obstructions, e.g. caused by trees and leaves, are
compensated and bridged by different fi lter algorithms.
A prototype for this kind of leader-follower-behavior was implemented
on top of “RTS-Dora”, one of the mobile robotic
platforms of the Institute for Systems Engineering. With a total
weight of 450kg this car-like platform enables following with
a top speed of about 14 km/h (4m/s).
FORSCHUNGSZENTRUM FORSCHUNGSZENTRUM L3S L3S · · L3S L3S RESEARCH RESEARCH CENTER CENTER
summary
In this project a so-called electronic drawbar
was developed for unmanned ground vehicles.
This function enables robotic vehicles
to follow autonomously a leading person or
another vehicle in selectable distances. A
prototype for this application was set up and
demonstrated on various events throughout
the year.
Presentations
The electronic drawbar for unmanned ground vehicles was
developed at the Leibniz University Hannover from November
2005 to May 2006 and successfully demonstrated at the
Rheinmetall test site in Unterlüß in April 2006. At the ELROB
in May 2006 the electronic drawbar was introduced to broad
public with positive resonance. Furthermore, the Institute
for Systems Engineering used this particular event to demonstrate
autonomous and semi-autonomous driving in urban
environments.
In July 2006, the leader-follower-behavior was demonstrated
within the Tech Buffet 2006 at the University of Hannover.
Students were encouraged to guide the robot “RTS-Dora”
along a predefi ned track as fast as possible. With a total number
of 50 students operating the robot safely, the easy and
intuitive controllability of the electronic drawbar was shown
even by leaders unfamiliar with the following robot.

DISTRIBUTED SYSTEMS AND NETWORKS PROJECTS
selected publications
Oliver Wulf and Bernardo Wagner: Fast 3D-Scanning
Methods for Laser Measurement Systems. In:
Proceedings of the International Conference on
Control Systems and Computer Science (CSCS14),
July 2-5, 2003, Bucharest, Romania.
Oliver Wulf, Kai O. Arras, Henrik I. Christensen and
Bernardo Wagner: 2D Mapping of Cluttered Indoor
Environments by Means of 3D Perception. In: Proceedings
of the IEEE/RAS International Conference
on Robotics and Automation (ICRA), April 26-May
1, 2004, New Orleans, USA.
info box
Project Type: Industrial project
Research Areas: Autonomous service robot, 3D
perception, Object recognition
Contact: Prof. Dr.-Ing. Bernardo Wagner,
wagner@L3S.de
Dipl.-Ing. Matthias Hentschel,
hentschel@rts.uni-hannover.de
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PROJECTS TECHNOLOGY DISTRIBUTED SYSTEMS ENHANCED AND LEARNING NETWORKS
KIOP – An Indoor Localization System for Persons Based
on Channel-Estimation Information
Indoor localization systems for persons offer a great variety of potential applications. Especially the
combination of localization and communication enables various location based services (LBS). The DFG
Research Grant KIOP investigates methods and algorithms targeting theses systems using simulations
and real-word measurement setups.
In a radio based communication and localization system, the
position of a radiating source is typically estimated via the
analysis of signals received at a certain number of sensors or
vice versa. This approach is normally based on measuring
ranges or range differences (by means of time of arrival or
time difference of arrival measurements) between sources and
sensors, and subsequent processing of range information into
position estimates. Several conditions have to be fulfi lled in
order to get accurate position estimates:
• the receiver has to be able to estimate arrival times,
• the signal structure must enable the receiver to detect the
arrival time,
• the signal must have the possibility to travel in a direct line
of sight (LOS), and
• the receiver must detect the correct LOS path in multi-path
and interference environments
As typical indoor environments are exposed to relatively harsh
multi-path and interference conditions, methods and algorithms
have to be developed, in order to ensure robust and
accurate positioning.
R&D Highlights and Project Results
During this two year research project a variety of approaches
targeting reliable localization have been analyzed by analytical
investigation, simulation environments, real-word measurements
and test-beds, e.g.:
• A localization test-bed for Ultra-Wideband (UWB) and IEEE
802.11b wireless LAN has been developed and implemented
using a high speed digital sampling oscilloscope and a standard
PC running MATLAB.
• A low-cost experimental bi-phase UWB pulse generator, us-
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
ing the avalanche effect of two bi-polar transistors, has been
developed and implemented.
• Impulsive Ultra-Wideband signals have been compared to
standard IEEE 802.11b wireless LAN signals regarding their
indoor localization possibilities in an industrial storage environment.
• Non line of sight (NLOS) detection and mitigation algorithms
have been developed and compared by simulation as
well as real-word measurements.
• One example of integrating redundant relative positioning
information, generated by a low-cost inertial measurement
unit (IMU) has been investigated and implemented.
Potential Applications
Indoor localization systems for persons offer a great variety of
potential applications. Especially the combination of localization
and communication enables various location based services
(LBS) such as: visitor guidance and information systems
for individual guidance/navigation in museums, public buildings,
trade fairs or shopping malls. Another fi eld of potential
applications is the guidance and support of fi rst responders in
buildings with reduced visibility due to fi re or smoke. A third
application fi eld is industrial tasks involving logistic or security
scenarios.
summary
The DFG Research Grant KIOP investigates
indoor localization methods and algorithms
using simulations and real-word measurement
setups.

DISTRIBUTED SYSTEMS AND NETWORKS PROJECTS
selected publications
J. Schroeder, S. Galler, and K. Kyamakya: A Low-
Cost Experimental Ultra-Wideband Positioning
System, presented at IEEE International Conference
on Ultra-Wideband, Zurich, 2005
S. Galler, J. Schroeder, G. Rahmatollahi, K. Kyamakya,
and K. Jobmann: Analysis and practical
comparison of Wireless LAN and Ultra-Wideband
technologies for advanced localization, presented
at Position, Location and Navigation Symposium
- PLANS, San Diego, USA, 2006
J. Schroeder, S. Galler, K. Kyamakya, and K. Jobmann:
NLOS detection algorithms for Ultra-Wideband
localization, 4th Workshop on Positioning,
Navigation and Communication (WPNC‘07), Hannover,
Germany, 2007
info box
Project Type: DFG Research Grant
Duration: February 2005 – February 2007
Research Areas: Indoor Localization Methods and
Algorithms
Contact: Stefan Galler, galler@L3S.de
Jens Schroeder, jens.schroeder@ikt.uni-hannover.de
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER 73

PROJECTS NEWS AND EVENTS
golden autumn technology enhanced learning flower
restaurant in the middle of nowhere cooperation five
interfaces know a good cook navigation forest full of b
gymnastics participants phone book efficiently fitnes
74
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER

NEWS AND EVENTS
power cluster projects green fee competitive chinese
fingers and two feet web usage blue wave browser
ikes hypertext black cat international top researchers
s drink learn more never hesitate search architecture
+++ The L3S is a global hub for theoretical and
applied research on information, learning and
knowledge technologies. L3S‘ activities range from
research to consulting and technology transfer. L3S
staff members participate and organize important
events and are visible both inside and outside the
research community +++
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
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PROJECTS NEWS AND EVENTS
L3S Research Center at CeBIT 2007
As in the previous years, L3S presents at CeBIT 2007. Besides providing an overall presentation
of L3S research achievements and results, the CeBIT 2007 presentations of L3S Research
Center will focus on five major products and services; exemplifying our continuous quest for
intelligent integration and application of data and information in knowledge-intensive enterprises
and institutions. (hall 3, E47 and hall 9, C21)
Beagle++ Desktop Search
Beagle++ is a tool for organizing, searching and integrating personal information spaces
of today’s knowledge workers. Beagle++ indexes the content of all fi les on your desktop
and in your workgroup, including Offi ce documents, emails, images, music, video
fi les, or source code. To provide rich semantic relations among your documents and
other entities represented on your desktop, Beagle++ extracts the metadata associated
with desktop fi les as well as their context and usage patterns. For example, Beagle++
supports keyword searches to retrieve scientifi c articles that were originally received as
email attachments and subsequently stored as a fi le in the user´s local desktop. Specifi cally, during such a search, Beagle++ not
only returns the fi le and the connection to the original email, but also related information from the email communication as
well as bibliographic information, conference links, author information and relevant references to the article.
Beagle++ and related tools are being developed together with a number of European research institutions and companies,
including: DFKI and SAP in Germany, EPFL in Switzerland, IBM, HP and DERI in Ireland.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER

WebRatio® Competence Center Germany
For model-driven web application development of data-rich web applications,
L3S Research Center offers consultation and training as the WebRatio® Competence
Center in Germany. WebRatio® is the result of years of extensive research
and application in many different industry sectors. WebRatio® is the world‘s
fi rst development environment to integrate advanced capabilities such as:
• the development of Web applications through a visual model (WebML®) and
their integration with third party solutions via Web Services (SOA)
• automatic code generation of J2EE compliant applications ready for deployment
• extensive support for documentation, maintenance and evolution of deployed
applications
In this context, we cooperate with Web Models in Milano and iSearch IT Solutions
in Hannover.
Knowledge-based Hotline Support System
Good hotline support relies on a rich and well-organized knowledge base about relevant cases
and their characteristics. L3S Research Center has developed a know ledge-based hotline support
system that exploits the semantics of important topics in order to identify similar cases
stored in the hotline support knowledge base. The system uses techniques such as: phrase
detection, semantic relations in sentences, stemming, part-of-word detection, and stopword removal
to easily fi nd related cases starting from the error message, as specifi ed by the customer
calling the hotline. Each technique can be customized separately and further domain specifi c
solutions can be added. The system has been developed together with IPH.
ELEONET: The Search Portal for Learning Objects
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
NEWS AND PROJECTS EVENTS
ELEONET is an emerging European portal for Learning Objects using Digital Object Identifi ers (DOIs), and has development
partners and publishers from Italy, UK, Germany and Spain. Effective search over Learning Object (LO) metadata and persistent
DOIs make this service especially valuable for producers and publishers of learning objects. ELEONET Portal provides a common
interface which allows Learning Object producers to register DOIs and to upload metadata. LO metadata records are indexed by
every registration agency and combined into a distributed search architecture, which allows both full-text and metadata search.
Learning Object descriptions and system interfaces currently exist in the English, German, Italian and Spanish languages.
FedSearch – A Common Search Infrastructure for Digital Libraries
L3S Research Center presents an innovative distributed search engine system which enables the user to simultaneously perform
full-text queries or attribute-specifi c searches (like author, year of publication etc.) in heterogeneous digital libraries over the
internet. What is unique with our approach to federated search is the fact that digital libraries can participate in a federation of
digital libraries with low effort and while keeping their existing library-specifi c workfl ow intact.
A novel plugin architecture facilitates interaction between otherwise incompatible
systems. The architecture provides an improved and unifi ed
search functionality within the Federation (particularly a consistent ranking
of the search results. Surrounding conditions, requirements and processes
(like document management, licensing models, legal restrictions, payment
options) remain unchanged.
The L3S Federated Search System has been tested successfully with various
search engines, particularly with FAST Data Search. The plugin component
itself is based upon the open source search platform „Lucene“, which has
been extended appropriately to support federated search.
The system has been developed within a DFG-founded project in collaboration
with the German National Library for Science and Technology, Bielefeld
University Library, FIZ Technik and Vascoda.
77

78
PROJECTS NEWS AND EVENTS
L3S supports international violin contest
Thirty-four selected violinists from fi fteen countries participated in the Hannover 6th International Violin Contest, an event
dedicated to Joseph Joachim. The Stiftung Niedersachsen has organized this tri-annual classic event since 1991 with its partners,
Staatsoper Hannover, HMTH and the NDR. This year offered two special features; the fi rst being an Audience Award, given for
the fi rst time. In the second feature, the international violin contest of Hannover provided an unprecedented live internet stream
of all its violinist’s performances.
The live streaming represents an exceptional way for modernday
contests to be held. The contestants appeared as online
pioneers, having their own contest homepage since the mid
nineties and in 1994 they provided a public viewing in front
of the concert hall.
This year, an audio-visual live presentation of all performances
of the participants was given. The fi rst four rounds were
shown on www.violin-wettbewerb.de and the fi nal round was
broadcast on www.ndrkultur.de.
Selected moderations were provided in German and English
and made available for download after each round.
Interested fans across the world, were given the opportunity to learn about the violin contest. L3S provided the entire technical
facilities for streaming and pre-event consultation. Additionally, the recordings and daily features were provided and hosted as
on-demand videos by the L3S.
L3S Researchers Win Best Student Paper Award
at Leading Semantic Web Conference
A joint team of researchers from L3S and University of Aberdeen
received the Best Student Paper Award at the International
Semantic Web Conference 2006, the leading conference
in this research area. The award ceremony took place at
the University of Georgia convention center in Athens, USA.
The award-winning work was conducted as part of the EUfunded
Network of Excellence KnowledgeWeb, which supports
the transition process of Semantic Web technology
from the world of Academia to the world of Industry.
When users search on the Semantic Web, they do not want
to get back a complete list of maybe thousands of results,
but rather a ranked list of best hits. However, ‘best’ does not
mean the same for all users. Each individual user has his personal
preferences, which determine what he regards as best
results. To allow the expression of such user preferences, Wolf
Siberski and Uwe Thaden from L3S and Jeff Pan from University of Aberdeen have extended the upcoming standard query language
for the Semantic Web. Their paper ‚Querying the Semantic Web with Preferences‘ that won the award, combines existing
work from Semantic Web and from Databases and offers a comprehensive approach for preference support when searching in
semantically enriched information sources.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER

EC-TEL 2006 – Conference
series successfully started
http://www.ectel06.org
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
NEWS AND PROJECTS EVENTS
http://professional-learning-cluster.org
250 participants from more than 20 countries worldwide – an impressive outcome for the First European Conference on Technology
Enhanced Learning (EC-TEL 2006) which took place in Crete from October 1st to 4th, 2006. During this unique event,
the organizers succeeded in providing a common forum for leading researchers and stakeholders in the area of Technology
Enhanced Learning. In talks and workshops, the experts dealt intensively with topics such as Workplace Learning Infrastructures
for Learning and Metadata and Learning Objects. Furthermore, project meetings, of no less than eight EU projects dealing with
Technology Enhanced Learning, took place before and after the conference.
In preparation for the 7th Framework Program, starting
in January 2007, participating representatives of the EU-
Commission offered detailed insights into the structure of
the new Work Program. Technology Enhanced Learning,
which enables individuals and organizations to learn more
effi ciently and cost-effectively - independent of time, place
and pace, will still be one of the strategic goals of the EU/IST
Work Program.
The conference was organized by the Professional Learning
Cluster (PRO-LC) with the European Network of Excellence
PROLEARN and was coordinated by L3S Research Center.
PRO-LC has been founded by a cluster of major European
research projects with the aim of ultimately designing and
shaping Technology Enhanced Learning in Europe.
Quoting a statement from Prof. Wolfgang Nejdl, Program Chair EC-TEL, “The EC-TEL 2006 was a very successful start for our
annual conference series. We hope to have inspired the participants with new research ideas as well as to have enabled new
cooperation with other research groups.”
IBM recognizes L3S Ph.D.
student as one of Europe’s best
The IBM Software Development Laboratory in Rome, Italy will host this year’s EMEA (Europe Middle East and Africa) Best Student
Recognition Event. The EMEA Best Student Recognition Event will bring together the top 75 students from across Europe,
the Middle East and Africa. Gianluca Demartini, one of many top, international researchers at the L3S Research Center in Hannover,
is an EMEA Best Student participant.
Gianluca Demartini, born in 1981, joined the L3S Research Center / University of Hannover recently and is now working under
the supervision of Prof. Wolfgang Nejdl. He holds a M.Sc. from the University of Udine in Italy. Prior to graduation, he was a
world fi nalist of the Microsoft Imagine Cup 2005 competition presenting the TellMe project. In his Master thesis entitled “Evaluation
in Information Retrieval”, he tested and analyzed an Evaluation Metric for the Information Retrieval (ADM). His current
work within the European Integrated Project NEPOMUK, one of many international research projects at L3S, includes research
and development of the Beagle++ search engine.
79

80
PROJECTS NEWS AND EVENTS
Best Student Paper Award at WWW2006
Browser interfaces need to catch up with current Web usage
A paper on the results of a long-term client-side Web usage study won
the Best Student Paper Award at the World Wide Web 2006 Conference in
Edinburgh. The results show that although user interaction with the Web
has changed dramatically in the past decade, these changes have not been
incorporated into current browser interfaces. Since the latest comparable
study is several years old, this study was long overdue.
Between late 2004 and early 2005 the Web activities of twenty-fi ve users
were logged for an average period of three months. In addition to the basic
page access data, detailed user interface actions have been recorded by a
proxy server and an instrumented version of the Firefox browser. The paper
reports on three aspects of Web navigation.
Among the prominent results is the increased use of multiple windows and browser tabs. This strategy is often used for comparing
search results side by side. However, users often have diffi culty managing the number of open windows or tabs; further, in
order to backtrack, they need to remember what actions were performed in which window.
It became apparent that the Web has evolved from a mainly static hypertext system to an interactive system, in which people
carry out activities such as shopping and travel planning. The communication protocols used for these activities often disrupt
the functionality of the back button. Moreover, subjectively important pages – such as travel plans and cash receipts – are volatile;
they will get lost upon closing of the browser window.
From the speed of navigation actions, it becomes clear that users mainly scan pages, and that the speed of the Web is still not
suffi cient to meet current user interface standards. Data on user scrolling behavior provides new input for the still heated debate
to what extent scroll bars are acceptable in Web page design. Several further fi ndings and design implications are reported
in the paper. Even though many observations might seem obvious from casual introspection of Web usage, these specifi c fi ndings
provide important pointers for breakthroughs in Web user interface design.
The study was carried out by four Ph.D. students: Harald Weinreich, Hartmut Obendorf and Matthias Mayer from the University
of Hamburg, and Eelco Herder from the University of Twente in the Netherlands; since March 1, 2006, Eelco works as a postdoc
at the L3S Research Center.
Stud.IP developer workshop
The Leibniz University Hannover is one of the biggest universities in the Stud.IP project and the L3S Research Center is responsible
for the support and service of the local Stud.IP-system. L3S has done tremendous work
to successfully connect Stud.IP with the offi cial course management system HIS-LSF.
In early June, the 3rd Stud.IP developer workshop was held at the Leibniz University
Hannover. Besides the communication between developers and interested people from
different locations, the workshop aided in informing participants about the current successes
and future developments of the Stud.IP learning and course management system.
The main focus of the workshop was the discussion of systems interfaces and the
new challenges in course management (e.g. modularization of study courses) and new
technologies for Stud.IP.
The workshop was oriented towards those who will work on the further technical developments
of Stud.IP.
Topics of the single workshops were:
- mapping of modular study courses
- connection of Stud.IP to HIS-LSF and other systems
- development of a SOAP interface
- Roll out of a centralised help for all locations
- plugin interface
- virtual exams with ViPs
- highly available Stud.IP server
The developer workshop was a big success. More than 50 interested people took part in sharing their opinions and ideas. Also,
taking with them, the new ideas and concrete decisions made with, and on behalf of, the Stud.IP open source community.
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER

European Projects Join Forces
in Professional Learning
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
NEWS AND PROJECTS EVENTS
http://www.professional-learning-cluster.org
More than 50 top research institutes and companies join forces to advance research and application of technology enhanced
learning in companies and continuing education. The new Professional Learning Cluster PRO-LC bundles the work of four major
European projects (the PROLEARN Network of Excellence and the Integrated Projects PROLIX, TENCompetence and APOSDLE)
as well as several specifi c targeted research projects such as COOPER and iCAMP. The projects are funded through the 6th framework
programme of the EC/IST unit on Learning and Cultural Heritage with a joint budget of more than 50 Million Euro. Initiated
by the PROLEARN Network of Excellence, the cluster members focus on integrating technology enhanced learning, knowledge
management and business process management in professional learning environments. PROLIX will provide solutions for the
modular combination of eLearning environments with business process modeling tools, TENCompentence will support lifelong
competence development of individuals, teams and organizations by developing a service-based and open source European
infrastructure. APOSDLE will enhance knowledge worker productivity by supporting informal learning activities in the context of
knowledge workers‘ everyday work processes and within their computational work environments.
Prof. Wolfgang Nejdl, coordinator of PROLEARN and director of the L3S research center, stresses the need for integration: “European
companies need to consolidate technology enhanced learning solutions and integrate them with the rest of their IT and
business process infrastructures. The PRO-LC cluster projects will give Europe a competitive advantage in this important area.”
PRO-LC will serve as one stop shop for information, competencies and solutions for Europe‘s companies and research organizations
in the emerging fi eld of Technology Enhanced (Professional) Learning.
The PRO-LC Cluster will facilitate and strengthen the close cooperation between all involved research institutes and companies,
enable sharing of results and infrastructures, and identify emerging research issues in technology enhanced learning relevant for
future initiatives and programs. PRO-LC member will jointly work on European and world-wide standardization efforts, e.g. at
CEN/ISSS and IEEE standardization bodies.
81

PROJECTS WORK & COLLABORATION
challenges spring is when winter is over meetings fl
publications s t r a w b e r r y i c e c r e a m w i t h n u t s chances sunr
membership shark alarm in the underground internatio
tahiti is great for skiing advisory board river in the moun
sunshine today in the kitchen conferences favourite son
82
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER

WORK & COLLABORATION
y ing behind the rainbow investigation mickey mouse
se at lunchtime papers beach beauty program committee
al partners early espresso at six industry collaboration
tains work together travel around the world projects no
g on the radio consult with her aunt and uncle discuss
+++ The most important criteria to measure the success
of a research center like L3S are quality and quantity
of publications and valuable partnerships. L3S has
published more than 100 articles and has strong and
important partnerships with research and industrial
institutions. +++
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
83

84
PROJECTS INTERNATIONAL PARTNERS
• Acklin B.V., Wallwijk, Niederlande
• Albert-Ludwigs-Universität Freiburg
• Alexandru Ioan Cuza University of Iasi, Rumänien
• Brandenburg University of Technology Cottbus
• Centre for Research and Technology Hellas, Thessaloniki,
Griechenland
• Cognium Systems, Paris, Frankreich
• ComLinx IT Services, Kassel
• Deutsches Forschungszentrum für Künstliche Intelligenz
GmbH (DFKI), Germany
• Deutsches Forschungszentrum für Künstliche Intelligenz,
Kaiserslautern, Deutschland
• École Polytechnique Fédérale de Lausanne Lausanne, Schweiz
• Ecole Polytechnique Federale de Lausanne, Schweiz
• École Polytechnique Fédérale de Lausanne, Switzerland
• EDGE-IT / Mandriva, Paris, Frankreich
• Eigenössische Technische Hochschule Zürich, Switzerland
• Federal University of Amazonas, Manaus, Brasilien
• Forschungszentrum Informatik, Universität Karlsruhe,
Deutschland
• Foundation of Research and Technology – Hellas Heraklion, GR
• France Telecom, Cesson Sévigné, Frankreich
• Fraunhofer-Gesellschaft zur Förderung der angewandten
Forschung e.V. (FHG), Germany
• Fundació Barcelona Media Universitat Pompeu Fabra, Spain
• GIUNTI Interactive Labs s.r.l., Italy
• Hautes Etudes Commerciales, France
• Helsinki University of Technolog, Finland
• Heriott-Watt University Edinburgh, UK
• Högskolan i Skövde, SE
• HP Galway, Irland
• IBM Galway, Irland
• Il Centro per la ricerca scientifica e tecnologica, Italien
• information multimedia communication AG, Germany
• Innofinity GmbH, Kassel
• Inria Loria Nancy, FR
• INRIA Rocquencourt Paris, FR
• Inst. National de Recherche en Informatique et
en Automatique, Montbonnot, Frankreich
• Institut National des Télécommunications, France
• Institute of Communication and Computer Systems,
National University of Athens, Griechenland
• Institutul National de ercetare-Dezvoltare in Informatica
Bucharest, RO
• Instytut Podstaw Informatyki Polskiej Akademii Nauk Warsaw, PL
• Irion Management Consulting, Kaiserslautern, Deutschland
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
• Irion Management Consulting, Kaiserslautern, Deutschland
• Jozef Stefan Institute, Slovenia
• Katholieke Universiteit Leuven / ARIADNE Foundation,
Belgium
• Kungl. Tekniska Högskolan, Sweden
• Kungliga Teksnika Hoegskolan (KTH), Stockholm, Schweden
• Libera Università di Bolzano, Bozen, Italien
• Linköpings Universitet Linköping, SE
• LogicaCMG, Netherlands
• Ludwig-Maximilians Universität München
• Max-Plank Institut für Informatik, Saarbrücken, Deutschland
• National Centre for Scientific Research “Demokritos”, Greece
• National University of Ireland, Galway, Irland
• National University of Irland, Galway, Irland
• Open Universiteit Nederland, The Netherlands
• Open University, United Kingdom
• Politecnico di Milano, Italy
• Politehnica Universität Bukarest, Rumänien
• Poznan University of Ecomonics
• PRC Group, Athen, Griechenland
• Research Institute for Artificial Intelligence of the Romanian
Academy, Bukarest, Rumänien
• Rheinisch-Westfälische Technische Hochschule Aachen,
Germany
• SAP Deutschland
• Software de Base, S.A, Spain
• Stad Antwerpen, Belgium
• Stanford University, USA
• Stichting Telematica Instituut, Niederlande
• SURF, Netherlands
• Synergetics, Belgium
• Technische Universität Dresden
• Technische Universität Eindhoven, Niederlande
• Technische Universität München, Deutschland
• Technische Universität Wien, AT
• Technische Universität Wien, Österreich
• Technische Universiteit Eindhoven, Netherlands
• Thales Research and Technology, Paris, Frankreich
• The Open University, Milton Keynes, Großbritannien
• The University of Manchester, UK
• UNESCO-IHE Institute for Water Education
• Universidad Alcala de Henares, Spanien
• Universidad Polictécnica de Madrid, Spain
• Universidad Politécnica de Madrid, Madrid, Spanien
•
Universidad Rey Juan Carlos, Spanien

• Universidade Nova de Lisboa, PT
• Università Ca‘ Foscari Venezia, IT
• Università degli Studi di Torino, IT
• Università degli Studi di Trento, Trient, Italien
• Università di Napoli, IT
• Universität Duisburg-Essen, Deutschland
• Universität für Bodenkultur, Zentrum für Soziale Innovation,
Austria
• Universität Göttingen
• Universität Hannover
• Universität Innsbruck, Innsbruck, Österreich
• Universitat Politècnica de Catalunya, Barcelona, Spanien
• Universität St. Gallen, CH
• Universität Swizzera Italiana, Lugano, Schweiz
• Universität Zürich, CH
• University of Economics, Prag, Tschechien
• University of Liverpool, Liverpool, Großbritannien
• University of Malta, MT
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
INDUSTRY PARTNERS PROJECTS
• University of Manchester, Manchester, Großbritannien
• University of Sheffield, Sheffield, Großbritannien
• University of Warwick, United Kingdom
• University of Zurich, Schweiz
• Unversity of Aberdeen, Großbritannien
• Unversity of Eindhoven, Niederlande
• Unversity of Surrey, Großbritannien
• Vrije Universität Amsterdam, Niederlande
• Vrije Universiteit Amsterdam, Amsterdam, Niederlande
• Vrije Universiteit Brussel, Brüssel, Belgien
• Wirtschaftsuniversität Wien, Austria
•
Yahoo! Research, Barcelona, Spanien
85

86
PROJECTS PUBLICATIONS
Publications 2006
1. Abel, F.; Brunkhorst, I.; Henze, N.; Krause, D.; Mushtaq, K.;
Nasirifard, K.; Tomaschewski, K.: Personal Reader Agent:
Personalized Access to Configurable Web Services. ABIS 2006 -
14th Workshop on Adaptivity and User Modeling in Interactive
Systems, Hildesheim, October 9-11 2006.
2. Ackermann, Markus; Berendt, Bettina; Grobelnik, Marko;
Hotho, Andreas; Mladenic, Dunja; Semeraro, Giovanni;
Spiliopoulou, Myra; Stumme, Gerd; Svatek, Vojtech; van
Someren, Maarten: Semantics, Web and Mining. Springer,
Heidelberg, 2006.
3. Alrifai, Mohammad; Dolog, Peter; Nejdl, Wolfgang:
Learner Profile Management for Collaborative Adaptive
eLearning Application. APS‘2006: Joint International Workshop
on Adaptivity, Personalization and the Semantic Web at the
17th ACM Hypertext Conference, Odense, Denmark, August
2006. ACM Press.
4. Alrifai, Mohammad; Dolog, Peter; Nejdl, Wolfgang:
Transaction Concurrency Control in Web Service Environment.
ECOWS‘2006: The 4th European Conference on Web Services.
December 2006. IEEE Press.
5. Alves, Miguel; Viegas Damasio, Carlos; Olmedilla, Daniel;
Nejdl, Wolfgang: A distributed tabling algorithm for rule based
policy systems. In 7th IEEE International Workshop on Policies
for Distributed Systems and Networks (POLICY 2006), London,
Ontario, Canada, June 2006.
6. Grigoris Antoniou, Matteo Baldoni, Piero A. Bonatti,
Wolfgang Nejdl, and Daniel Olmedilla. Rule-based policy
specification. In Ting Yu and Sushil Jajodia, editors, Secure Data
Management in Decentralized Systems. Springer, 2007.
7. Aroyo, Lora; Dolog, Peter; Houben, Geert-Jan; Kravcik,
Milos; Naeve, Ambjoern; Nilsson, Mikael; Wild, Fridolin:
Interoperability in Personalized Adaptive Learning. Educational
Technology & Society 9(2): 4-18 (2006).
8. Van Assche, Frans; Duval, Erik; Massart, David; Olmedilla,
Daniel; Simon, Bernd; Sobernig, Stefan; Ternier, Stefaan; Wild,
Fridolin: Spinning interoperable applications for teaching &
learning using the simple query interface. Educational
Technology & Society. Special Issue (April 2006) on
Interoperability of Educational Systems, 9(2):51-67, 2006.
9. Baldoni, M.; Baroglio, C.; Brunkhorst, I.; Henze, N.;
Marengo, E.; Patti, V.: A Personalization Service for Curriculum
Planning. ABIS 2006 - 14th Workshop on Adaptivity and User
Modeling in Interactive Systems, Hildesheim, October 9-11 2006.
10. Balke, W.-T.; Thaden, U.; Diederich, J.: The Semantic
GrowBag Demonstrator for Automatically Organizing Topic
Facets, in Proceedings of the SIGIR2006 Workshop on Faceted
Search, Seattle, USA, August 2006.
11. Balke, W.-T.; Diederich, J.: A Quality- and Cost-based
Selection Model for Multimedia Service Composition in Mobile
Environments, ICWS 2006, Chicago, USA.
12. Balke, Wolf-Tilo; Guentzer, Ulrich; Siberski, Wolf:
Exploiting Indifference for Customization of Partial Order
Skylines. Proceedings of the 10th International Database
Engineering & Applications Symposium (IDEAS), Delhi, India,
2006.
13. P. Barahona, F. Bry, E. Franconi, N. Henze, U. Sattler (Eds.):
Reasoning Web. Springer, 2006, ISBN 3-540-38409-X.
14. Barji, A., Hagge, N., and Wagner, B.: Comparative Study of
Using CNet, IEC61499, and Statecharts for Behavioral Models of
Real-time Control Applications. 11th IEEE International
Conference on Emerging Technologies and Factory Automation
(ETFA 2006), September 20-22, 2006, Prague, Czech Republic.
15. Belizki, Jürgen; Costache, Stefania; Nejdl, Wolfgang:
Application Independent Metadata Generation. In Proceedings
of the International ACM Workshop on Contextualized
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
Attention Metadata: Collecting, Managing and Exploiting of
Rich Usage Information, CAMA, Arlington, Virginia, USA,
November, 2006.
16. Bonatti, Piero A.; Duma, Claudiu; Fuchs, Norbert; Nejdl,
Wolfgang; Olmedilla, Daniel; Peer, Joachim; Shahmehri, Nahid:
Semantic web policies - a discussion of requirements and
research issues. In 3rd European Semantic Web Conference
(ESWC), volume 4011 of Lecture Notes in Computer Science,
Budva, Montenegro, June 2006. Springer.
17. Bonatti, Piero A.; Ding, Li; Finin, Tim; Olmedilla, Daniel
(editors). Proceedings of the ISWC‘06 2nd International
Semantic Web Policy Workshop (SWPW), Athens, Georgia, USA,
November 2006.
18. Bonatti, Piero; Olmedilla, Daniel; Peer, Joachim: Advanced
policy explanations. In 17th European Conference on Artificial
Intelligence (ECAI 2006), Riva del Garda, Italy, Aug-Sep 2006.
IOS Press.
19. Bongio, Aldo; van Bruggen, Jan; Ceri, Stefano; Cristea,
Valentin; Dolog, Peter; Hoffman, Andreas; Matera, Maristella;
Mura, Marzia; Taddeo, Antonio; Zhou, Xuan: COOPER: Towards
A Collaborative Open Environment of Project-centred Learning,
Proceedings of the First European Conference on Technology
Enhanced Learning (EC-TEL 2006), Crete, Greece.
20. Brase, Jan; Bertelmann, Roland; Diepenbroek, Michael;
Grobe, Hannes; Hueck, Heinke; Lautenschlager, Michael;
Schindler, Uwe; Sens, Irina; Waechter, Joachim: Data
publication in the Open Access initiative, Data Science Journal,
Volume 5 (2006), pp.79-83, ISSN: 1683-1470.
21. Breitner, M.H.; Bruns, B.; Lehner, F.: Neue Trends im
ELearning - Aspekte der Betriebswirtschaftslehre und
Informatik, Fachbuch, Physica/Springer Verlag, Heidelberg
Sommer 2006
22. Breitner, M.H.; Fandel, G.: ELearning Geschäftsmodelle
und Einsatzkonzepte (PDF-Datei, 0.2 MB), ZfB Special Issue
2/2006, Gabler Verlag 2006, Februar 2006
23. Breuer, F.; Breitner, M.H.: Presentation of an eLearning
Marketing Concept for Adult Education Institutions, in:
Breitner, M. H.; Bruns, B.; Lehner, F. (Hrsg.): Neue Trends im
ELearning - Aspekte der Betriebswirtschaftslehre und
Informatik, Fachbuch, Physica/Springer Verlag, Heidelberg
Sommer 2006
24. Brüggemann, T.; Breitner, M.H.: Mobile
Preisvergleichsdienste am Scheideweg. In:
Wirtschaftsinformatik, Heft 6, 2006, S. 430 - 436. Dezember
2006
25. Brunkhorst, Ingo; Chirita, Paul-Alexandru; Costache,
Stefania; Gaugaz, Julien; Ioannou, Ekaterini; Iofciu, Tereza;
Minack, Enrico; Nejdl, Wolfgang; Paiu, Raluca: The Beagle++
Toolbox: Towards an Extendable Desktop Search Architecture.
Semantic Desktop Workshop 2006, Nov. 2006, Athens, GA,
USA.
26. Brunkhorst, Ingo; Olmedilla, Daniel: Interoperability for
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TEL), Heraklion, Greece, Oct 2006. Springer.
27. Bruns, C.; Jobmann, K.: Evaluation of Server Performance
in VANETs in Single-Hop Scenarios 3rd International Workshop
on Intelligent Transportation, WIT 2006.
28. Burgos, Daniel; Memmel, Martin; Olmedilla, Daniel; Ras,
Eric; Weibelzahl, Stephan; Wolpers, Martin (editors): Joint
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Development and Knowledge Management, Heraklion, Greece,
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29.
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30. Chen, H., Wulf, O. and Wagner, B.: A Mixed Reality based
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32. Chen, Ling; Bhowmick, Sourav S; Li, Jinyan: COWES:
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33. Chen, Ling; Bhowmick, Sourav S.; Li, Jinyan: Mining
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34. Cheniti-Belcadhi, Lilia; Henze, Nicola; Braham, Rafik:
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ICALT 2006: 586-590.
35. Chernov, Sergey; Iofciu, Tereza; Nejdl, Wolfgang; Zhou,
Xuan: Extracting Semantic Relationships between Wikipedia
Categories. 1st International Workshop: „SemWiki2006 - From
Wiki to Semantics“ (SemWiki2006), co-located with the
ESWC2006 in Budva, Montenegro, June 12, 2006.
36. Chernov, Sergey; Kohlschütter, Christian; Nejdl, Wolfgang:
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Libraries. In Proceedings of 9th International Conference on
Asian Digital Libraries (ICADL 2006), Kyoto, Japan, November
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37. Chirita, Paul-Alexandru; Firan, Claudiu S.; Nejdl,
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38. Chirita, Paul-Alexandru; Firan, Claudiu S.; Nejdl,
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39. Chirita, Paul-Alexandru; Costache, Stefania; Nejdl,
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40. Chirita, Paul-Alexandru; Nejdl, Wolfgang: Analyzing User
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41. Chirita, Paul-Alexandru; Gaugaz, Julien; Costache,
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42. Cho, SungRan; Koudas, Nick; Srivastava, Divesh: Metadata
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43. Cristea, Alexandra; Nejdl, Wolfgang: Adaptive Authoring
of Adaptive Courses on the Semantic Desktop via Malleable
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44. Datta, Anwitaman; Nejdl, Wolfgang; Aberer, Karl: Optimal
caching for first-order query load-balancing in decentralized
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45. Juri L. De Coi, Eelco Herder, Arne Koesling, Christoph Lofi,
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INSTICC Press.
46. Demartini, Gianluca; Mizzaro, Stefano: A Classification of
IR Effectiveness Metrics. In Proceedings of the 28th European
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47. Demidova, Elena; Nejdl, Wolfgang: Integrating RDF
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In ASWC 2006 Workshops Proceedings, Beijing, China,
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48. Elena Demidova, Stefaan Ternier, Daniel Olmedilla, Erik
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Integration of heterogeneous information sources into a
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49. Diederich, J.; Iofciu, T.: Finding Communities of Practice
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50. Diederich, J; Nejdl, W.;Tolksdorf, R.: EASE: The European
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51. Dolog, Peter; Stuckenschmidt, Heiner; Wache, Holger:
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52. Finin, Tim; Kagal, Lalana; Olmedilla, Daniel: Report on the
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53. Finin, Tim; Kagal, Lalana; Olmedilla, Daniel, editors.
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Edinburgh, Scotland, May 2006.
54. Galler, S.; Schroeder, J.; Rahmatollahi, G.; Kyamakya, K.;
Jobmann, K.: Analysis and practical comparison of Wireless LAN
and Ultra-Wideband technologies for advanced localization
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55. Gietz, P.; Grimm, C.; Pfeiffenberger, H.; Rauschenbach, J.;
Schroeder, R.: DFN-AAI: Technische und organisatorische
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56. Grimm, C.: Technische Infrastrukturen für eScience an
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57. Grimm, C.; Pattloch, M.; Reiser, H.: Sicherheit in Grids, In:
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58. Grimm, C.; von Voigt, G.: Security als Service. In: O.
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59. Grimm, C.; Piger, S.; Wiebelitz, J.: Evaluation von Security-
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60. Hagge, N. and Wagner, B.: Applying the Handler-based
Execution Model to IEC 61499 Basic and Composite Function
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61.
Hagge, N. und Wagner, B.: Konsistentes Verschalten Petri-
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62. Härke, S.; Krüger, M.; Breitner, M.-H.; Jobmann, K.:
Geschäftsmodelle für Multimediaräume in Hochschulen In:
Breitner, M. H., Bruns, B. und Lehner, F.: ELearning ? Eine
ganzheitliche Betrachtung. Physica/Springer Verlag,
Heidelberg, 2006
63. Heinrich; Feldmann, S.: Capacity and Fairness Evaluation
of IEEE 802.11-based Ad Hoc Networks with Multi-Hop Traffic
IEEE GLOBECOM Technical Conference, San Francisco,
California, USA, 27 November - 1 December 2006
64. Heinrich;Feldmann, S.: Capacity of IEEE 802.11-based Ad
Hoc Networks with Fairness Constraints IEEE International
Symposium on Personal, Indoor and Mobile Radio
Communications (PIMRC 2006), Helsinki, 11-14 September
2006
65. Hentschel. M., Wulf, O. and Wagner, B.: A Hybrid Feedback
Controller for Car-like Robots. Proceedings of the 3rd
International Conference on Informatics in Control, Automation
and Robotics. (ICINCO 2006), pp.445-450, August 1-5, 2006,
Setubal, Portugal.
66. Henze, Nicola and Krause, Daniel: User Profiling and
Privacy Protection for a Web Service Oriented Semantic Web.
ABIS 2006 - 14th Workshop on Adaptivity and User Modeling in
Interactive Systems, Hildesheim, October 9-11 2006.
67. Henze, Nicola and Krause, Daniel: Personalized Access to
Web Services in the Semantic Web. SWUI 2006 - 3rd
International Semantic Web User Interaction Workshop,
November 6, 2006, Athens, Georgia, USA, collocated with ISWC
2006
68. Henze, Nicola and Krause, Daniel: Scalable Matchmaking
for a Semantic Web Service based Architecture - Workshop on
Semantics for Web Services, December 4, 2006, Zurich,
Switzerland, collocated with ECOWS 2006
69. Henze, Nicola: Personalisierbare Informationssysteme im
Semantic Web. In T. Pellegrini, A. Blumauer (Hrsg.): Semantic
Web: Wege zur vernetzten Wissensgesellschaft. Springer, 2006,
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70. Henze, Nicola: A Definition of Adaptive Educational
Hypermedia Systems. Article in the Encyclopedia of Multimedia.
Springer, 2006, ISBN: 0-387-24395-X.
71. Henze, Nicola: Personalized eLearning in the Semantic
Web. First International Conference on Interactive Mobile and
Computer Aided Learning, Amman, Jordan, April 19-21 2006.
72. Henze, Nicola: Personalized eLearning in the Semantic
Web. Extended version of 4. International Journal of Emerging
Technologies in Learning (iJET), Vol. 1, No. 1 (2006).
73. Herder, Eelco; Weinreich, Harald; Obendorf, Hartmut; Mayer,
Matthias: Much to Know About History. AH 2006: 283-287.
74. Herder, Eelco; Koesling, Arne; Olmedilla, Daniel; Hummel,
Hans; Schoonenboom, Judith; Moghnieh, Ayman; Vervenne,
Luk: European lifelong competence development:
Requirements and technologies for its realisation. In Workshop
on Learning Networks for Lifelong Competence Development,
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75. Hirakawa, S.; Katoh, G.; Reimers, U.; Whitacker, J.; Wu, Y.:
Scanning the Issue. Proceedings of the IEEE, Vol. 94, No.1, S. 5-
7, Januar 2006.
76. Hirakawa, S.; Reimers, U.; Whitacker, J.; Wu, Y.: Overview
of Digital Television Development Worldwide. Proceedings of
the IEEE, Vol. 94, No.1, S. 8-21, Januar 2006.
77. Hoppe, G.; Breitner, M.H.: Evaluation and Optimization of
ELearning Scenarios, in: Breitner, M. H.; Fandel, G. (Hrsg.):
ELearning Geschäftsmodelle und Einsatzkonzepte, ZfB Special
Issue 2/2006, Gabler Verlag 2006, S. 43-61, Februar 2006
78. Hoser; Hotho, A.; Jäschke, R.; Schmitz, C.; Stumme, G.:
Semantic Network Analysis of Ontologies. In Y. Sure, J.
Domingue, editors, The Semantic Web: Research and
Applications, LNAI 4011, 411-426, Springer, Heidelberg, 2006.
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79. Hotho, Andreas; Jäschke, Robert; Schmitz, Christoph;
Stumme, Gerd: Information Retrieval in Folksonomies: Search
and Ranking. Proceedings of the 3rd European Semantic Web
Conference, 411-426, Budva, Montenegro, 2006.
80. Hotho, Andreas; Jäschke, Robert; Schmitz, Christoph;
Stumme, Gerd: BibSonomy: A Social Bookmark and Publication
Sharing System. Proceedings of the Conceptual Structures Tool
Interoperability Workshop at the 14th International Conference
on Conceptual Structures, 2006.
81. Andreas Hotho and Robert Jäschke and Christoph Schmitz
and Gerd Stumme. Emergent Semantics in BibSonomy. Proc.
Workshop on Applications of Semantic Technologies,
Informatik 2006, Dresden, 2006.
82. Andreas Hotho and Robert Jäschke and Christoph Schmitz
and Gerd Stumme. FolkRank: A Ranking Algorithm for
Folksonomies. Proc. FGIR 2006.
83. Andreas Hotho and Robert Jäschke and Christoph Schmitz
and Gerd Stumme. Trend Detection in Folksonomies. Proc. First
International Conference on Semantics And Digital Media
Technology (SAMT), Athens, Greece, 2006.
84. Jäschke, Robert; Hotho, Andreas; Schmitz, Christoph;
Stumme, Gerd: Wege zur Entdeckung von Communities in
Folksonomies. Grundlagen von Datenbanken 2006, 80 – 84.
85. Robert Jäschke and Andreas Hotho and Christoph Schmitz
and Bernhard Ganter and Gerd Stumme. TRIAS - An Algorithm
for Mining Iceberg Tri-Lattices. Proc. 6th ICDM, Hong Kong,
2006.
86. Predrag Knezevic, Andreas Wombacher, and Thomas Risse
DHT-based Self-adapting Replication Protocol for Achieving
High Data Availability In Proc. of 2nd International Conference
on Signal-Image Technology and Internet-Based Systems (SITIS
2006)
87. Köhncke, Benjamin; Balke, Wolf-Tilo: Personalized Digital
Item Adaptation in Service-Oriented Environments, in:
Proceedings of the 1st International Workshop on Semantic
Media Adaptation and Personalization (SMAP 2006), Athens,
Greece, 2006.
88. Köller, F.; Breitner, M.H.: Optimierung von
Warteschlangensystemen durch Approximation mit Neuronalen
Netzen, in: Haasis, H.-D.; Kopfer, H.; Schönberger, J. (Eds.):
Operations Research Proceedings 2005, Selected Papers of the
Annual International Conference of the German Operations
Research Society (GOR), Bremen, September 7-9, 2005,
Springer Verlag, Heidelberg, S. 263-268 15.08.2006
89. Kohlschütter, Christian; Chirita, Paul-Alexandru; Nejdl,
Wolfgang. Using Link Analysis to Identify Aspects in Faceted
Web Search. SIGIR 2006 Workshop on Faceted Search.
90. Kohlschütter, Christian; Chirita, Paul-Alexandru; Nejdl,
Wolfgang: Efficient Parallel Computation of PageRank. In
Proceedings of the 28th European Conference on Information
Retrieval (ECIR), London, United Kingdom.
91. Lecking, D., Wulf, O., and Wagner, B.: Variable Pallet Pickup
for Automatic Guided Vehicles in Industrial Environments.
11th IEEE International Conference on Emerging Technologies
and Factory Automation (ETFA 2006), September 20-22, 2006,
Prague, Czech Republic.
92. Martin, Gunnar; Leyking, Katrina; Wolpers, Martin:
Business Process-driven Learning. IST-Africa 2006 Conference
and Exhibition, Pretoria, South Africa, May 2006.
93.
Maske, P.; Breitner, M.H.: Qualification of Top and Middle
Managers with Special (M)obileLearning Scenarios, in:
Breitner, M. H.; Bruns, B.; Lehner, F. (Hrsg.): Neue Trends im
ELearning - Aspekte der Betriebswirtschaftslehre und
Informatik, Fachbuch, Physica/Springer Verlag, Heidelberg
Sommer 2006

94. Mertens, R.; Friedland, G.; Krüger, M.: To See or Not To
See: Layout Constraints, the Split-Attention Problem and their
Implications for the Design of Web Lecture Interfaces.
Proceedings of the World Conference on ELearning in
Corporate, Government, Healthcare, & Higher Education.
Waikiki Beach, Honolulu, Hawaii, Oct. 13-17, 2006
95. Della Mea, Vincenzo; Demartini, Gianluca; Di Gaspero,
Luca; Mizzaro, Stefano: Experiments on Average Distance
Measure. In Proceedings of the 28th European Conference on
Information Retrieval (ECIR), London, United Kingdom, pp 492-
495, 2006.
96. Naeve, A.; Lytras, M.; Nejdl, W.: Advances of the Semantic
Web for eLearning: expanding learning frontiers, in: British
Journal of Educational Technology 37 (3), May 2006.
97. Najjar, Jehad; Wolpers, Martin; Duval, Erik: Towards
Effective Usage-Based Learning Applications: Track and Learn
from User Experience(s). 6th IEEE International Conference on
Advanced Learning Technologies (ICALT 2006), July 2006,
Kerkrade, The Netherlands.
98. Najjar, Jehad; Wolpers, Martin; Duval, Erik: Attention
Metadata: Collection and Management, WWW2006 workshop
on Logging Traces of Web Activity: The Mechanics of Data
Collection, Edinburgh, Scotland, May 23, 2006.
99. Nejdl, Wolfgang; I. Cristea, Alexandra; Hendrix, Maurice:
Automatic and Manual Annotation Using Flexible Schemas for
Adoption on the Semantic Desktop, EC-TEL 2006, 88 – 102
100. Nejdl, Wolfgang; Tochtermann, Klaus (Eds.): Innovative
Approaches for Learning and Knowledge Sharing: First
European Conference on Technology Enhanced Learning, EC-
TEL 2006, Crete, Greece, October 1-4, 2006, Springer Lecture
Notes in Computer Science.
101. Nejdl, Wolfgang: Innovative Information and Knowledge
Infrastructures -- How do I find what I need? ADVIS‘06, Izmir,
Turkey, October 2006, Invited Talk.
102. Nejdl, Wolfgang: Innovative Information and Knowledge
Infrastructures -- How do I find what I need? ICALT‘06,
Kerkrade, Netherlands, July 2006, Invited Talk.
103. Niederberger, R.; Allcock, W.; Gommans, L.; Grünter, E.;
Metsch, T.; Monga, I.; Volpato, G. L.; Grimm, C.: Firewall Issues
Overview, GFD-I.083 Firewall Issues Research Group - Open
Grid Forum, August 2006.
104. Nüchter, A., Lingemann, J., Hertzberg, J. Wulf, O., Wagner,
B., Pervölz, K., Surmann, H. und Christaller, Th.: The RoboCup
Rescue Team Deutschland1. KI - Künstliche Intelligenz Heft
2/2006, S.24-29, ISSN 0933-1875, Böttcher IT Verlag, Bremen
105. Olmedilla, Daniel; Saito, Nobuo; Simon, Bernd (editors):
Educational Technology & Society. Special Issue (April 2006) on
Interoperability of Educational Systems, volume 9, 2006.
106. Olmedilla, Daniel: Security and privacy on the semantic
web. In Milan Petkovic and Willem Jonker, editors, Security,
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107. Papadopoulos, George A.; Stavrou Aristos; Papapetrou,
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108. Piger, S.; Grimm, C.; Wiebelitz, J.; Gröper, R.: An Approach
to Restricted Delegation of User Rights based on the gLite
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109. Prieß, A.; Schubert, C.; Zietz, C.; Breitner, M.H.:
Zweistufige Wirtschaftsinformatik-Ausbildung mit SAP-
Software am Institut für Wirtschaftsinformatik (IWI) der
Universität Hannover: Historie, Konzept, Erfolgsfaktoren und
Ausblick, in: Krcmar, H.; Rautenstrauch, C.; Wittges, H.;
Schrader, H. (Hrsg.): Wirtschaftsinformatik-Ausbildung mit
SAP-Software, Reader zum Track der Multikonferenz
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Wirtschaftsinformatik 2006 in Passau, EUL Verlag, Köln 2006, S.
233-262, September 2006
110. Reimers, U.: Perspektiven des terrestrischen Hör-, Fernsehund
Datenrundfunks. Fernseh- und Kinotechnik 60 (2006), Heft
3, S. 93-102.
111. Reimers, U.: DVB- The Family of International Standards
for Digital Video Broadcasting. Proceedings of the IEEE, Vol. 94,
No.1, S. 173-182, Januar 2006.
112. Reimers, U.: DVB-H und IP Datacast - Datenrundfunk und
hybride Kommunikationsnetze für mobile Endgeräte. VDE-
Kongress 2006, Tagungsband.
113. Rieger, S.; Gersbeck-Schierholz, B.; Mönnich, J.; Wiebelitz,
J.: Self-Service PKI-Lösungen for eScience, 13. DFN Workshop
„Sicherheit in vernetzten Systemen“, Hamburg, Germany,
March 2006.
114. Rückemann, C.-P.; Müller, W.; von Voigt, G.: Comparison
of Grid Accounting Concepts for D-Grid, In: Proceedings of the
Cracow Grid Workshop, CGW‘06, Cracow, Poland, October
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115. v. Voigt, G.; Rückemann, C.-P.; Müller, W.: Development of
a Billing Framework for D-Grid, Cracow Grid Workshop 06,
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116. Schmitz; Hotho, A.; Jäschke, R.; Stumme, G.: Kollaboratives
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117. Schmitz, Christoph; Hotho, Andreas; Jäschke, Robert;
Stumme, Gerd: Content Aggregation on Knowledge Bases using
Graph Clustering. Proceedings of the 3rd European Semantic
Web Conference, Budva, Montenegro, 2006.
118. Christoph Schmitz and Andreas Hotho and Robert Jäschke
and Gerd Stumme. Mining Association Rules in Folksonomies.
In V. Batagelj and H.-H. Bock and A. Ferligoj and A. _iberna,
editor(s), Data Science and Classification. Proceedings of the
10th IFCS Conf., 261--270, Springer, Heidelberg, 2006.
119. Siberski, Wolf; Pan, Jeff Z.; Thaden, U.: Querying the
Semantic Web with Preferences. “Best Student Paper Award”,
Proceedings of the 5th International Semantic Web Conference
(ISWC), Athens, GA, USA, 2006.
120. Simon, Bernd; Sobernig, Stefan; Wild, Fridolin; Aguirre,
Sandra; Brantner, Stefan; Dolog, Peter; Neumann, Gustaf;
Huber, Gernot; Klobucar, Tomaz; Markus, Sascha; Miklos,
Zoltan; Nejdl, Wolfgang; Olmedilla, Daniel; Salvachua, Joaquin;
Sintek, Michael; Zillinger, Thomas: Building blocks for the
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International Conference on Advanced Learning Technologies
(ICALT 2006), Kerkrade, The Netherlands, 2006.
121. Tedesco, Roberto; Dolog, Peter; Nejdl, Wolfgang:
Distributed Bayesian Networks for User Modeling. E-Learn‘06
Conference, Honululu, Hawaii, October 2006.
122. Tondl, P.; Jobmann, K.: Informationssysteme für die
Nutzung im Kraftfahrzeug - Fahrzeug-Fahrzeug-
Kommunikation in „Niccimon - Das Niedersächsische
Kompetenzzentrum Informationssysteme für die mobile
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123. Voigtländer, C.; Breitner, M.H.: Dynamic Alliances in
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Breitner, M. H.; Bruns, B.; Lehner, F. (Hrsg.): Neue Trends im
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Proceedings of the 12th International Conference on
Technology Supported Learning & Training (Online Educa),
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125. Voigtländer, C.; Breitner, M.H.: Hochschulen als
Weiterbildungspartner im Corporate Learning - Empirische
Ergebnisse und Kooperationsszenarien in: Proceedings der
GMW 2006 „Alltagstaugliche Innovationen“, ETH Zürich, 19. -
22.9.06, S. 226-237. September 2006
126. v. Holdt, U., Schneider, H., and Wagner, B.: Analyse von
Studienverläufen und Studienabbrüchen in den
Bachelorstudiengängen Informatik an der Leibniz Universität
Hannover. HDI 2006: Hochschuldidaktik der Informatik, in: GI-
Edition Lecture Notes in Informatics - Proceedings, 7.-8.
Dezember 2006, München, Germany
127. v. Mettenheim, H.-J.; Breitner, M.H.: Distributed
Neurosimulation, in: Haasis, H.-D.; Kopfer, H.; Schönberger, J.
(Eds.): Operations Research Proceedings 2005, Selected Papers
of the Annual International Conference of the German
Operations Research Society (GOR), Bremen, September 7-9,
2005, Springer Verlag, Heidelberg, S. 747-752 15.08.2006
128. v. Mettenheim, H.-J.; Breitner, M.H.: Dynamic Games with
Neurosimulators and Grid Computing: The Game of Two Cars
Revisited in: Proceedings of the 12th International ISDG
Symposium on Dynamic Games and Applications, July 3 - 6,
2006, Sophia Antipolis/Riviera 03.07.2006
129. Volpato, G.; Grimm, C.: Dynamic Firewalls and Service
Deployment Models for Grid Environments, Cracow Grid
Workshop 06, Cracow, Poland, October 2006.
130. Wagner, B.: Autonomous Vehicle for European Land-Robot
Trial. Robotics Today, Society of Manufacturing Engineers, 4th
Quarter 2006, Volume 19 No. 4
131. Wagner, B.: Graphic Course Design for Engineers.
International Conference on Engineering Education (ICEE-
2006), July 23-28, 2006, San Juan, Puerto Rico.
132. Wang, Hui; Srivastava, Divesh; Lakshmanan, V.S.; Cho,
SungRan; Amer-Yahia, Sihem: Optimizing Tree Pattern Queries
Over Secure XML Databases. Security in Decentralized data
Management, Springer, 15 December 2006.
133. Weinreich, Harald; Obendorf, Hartmut; Herder, Eelco;
Mayer, Matthias: Off the beaten tracks: exploring three aspects
of web navigation. WWW 2006: 133-142. Best Student Paper
Award.
134. Weinreich, Harald; Obendorf, Hartmut; Mayer, Matthias;
Herder, Eelco: Der Wandel in der Benutzung des World Wide
Webs. Proc. Mensch und Computer 2006, 2006. This paper
received the Best Paper Award from Mensch und Computer.
135. Weinreich, Harald; Obendorf, Hartmut, Herder, Eelco.
Data Cleaning Methods for Client and Proxy Logs. Proc.
Workshop Logging Traces of Web Activity: The Mechanics of
Data Collection, at WWW2006, 2006.
136. Wolpers, Martin; Martin, Gunnar: Integrating Research in
Professional Learning. International Journal of Knowledge and
Learning (IJKL), Vol. 2 Issue (3&4), Inderscience, 2006.
137. Wolpers, Martin; Hofer, Margit; Martin, Gunnar:
Professional Learning in Europe and beyond - Structures for
sustainable TEL-Research, Proc. 1st European Conference on
Technology Enhanced Learning (EC-TEL 2006), Crete, Greece,
October 2006.
138. Wolpers, Martin; Martin, Gunnar; Najjar, Jehad; Duval,
Erik: Attention Metadata in Knowledge and Learning
Management, Proc. 6th International Conference on
Knowledge Management, Graz, Austria, September 2006.
139. Wolpers, Martin; Martin, Gunnar: Advances in Technology
Enhanced Professional Learning - state of the art and future
trends, 28. International Exhibition-Congress on Chemical
Engineering, Environmental Protection and Biotechnology
(ACHEMA2006), Frankfurt am Main, Germany, May 2006.
140. Wulf, O., Lecking, D., and Wagner, B.: Robust Self-
Localisation in Industrial Environments based on 3D Ceiling
Structures. IROS 2006, October 9-14, Beijing, China
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
141. Wulf, O. and Wagner, B.: Navigation Mobile Robots with
3D Laser Data in Real Time. Workshop at the International
Conference Spatial Cognition, September 25, 2006, Bremen,
Germany.
142.
Zhou, Xuan; Nejdl, Wolfgang: Priority Based Load
Balancing in a Self-interested P2P Network, Proceedings of the
Fourth International Workshop on Databases, Information
Systems and Peer-to-Peer Computing (DBISP2P 2006), Seoul,
Korea.

Program Committee Memberships 2006
• ADALE - International Workshop on Adaptive Learning and
Learning Design, at the Adaptive Hypermedia and Adaptive
(Nejdl)
• International Conference on Intelligent User Interfaces (IUI),
Sydney, Australia, Jan. 29 to Feb. 01, 2006. (Henze)
• 4th International Conference on Formal Concept Analysis,
Dresden, 13.-17. Feb. 2006 (Stumme)
• International Conference Applied Computing 2006 (IADIS
2006), 25-28 February 2006, San Sebastian, Spain (Risse)
• Workshop on Productive Knowledge Work, Management
and Technological Challenges held in conjunction with the 4th
International Conference on Professional Knowledge Management,
Potsdam, Germany, March 28 – 30, 2006 (Chirita)
• Workshop Learning Networks for Lifelong Competence
Development March, 30-31, 2006, Sofia, Bulgaria (Nejdl)
• 1st International Workshop on Security and Trust in Decentralized/Distributed
Data Structures (STD3S 2006) in conjunction
with the 22nd International Conference on Data Engineering
(ICDE‘06) April 3-7, 2006, Atlanta, GA, USA (Risse)
• Daniel Olmedilla, Nobuo Saito, and Bernd Simon, editors.
Special Issue (April 2006) of the Journal of Educational
Technology and Society (endorsed by IEEE Technical Committee
on Learning Technology) on Interoperability of Educational
Systems, volume 9, April 2006. Guest Editor (Olmedilla)
• 11th Intl. Conference on Database Systems for Advanced
Applications, Singapore, April 12 - 15, 2006 (Nejdl)
• The IEEE 20th International Conference on Advanced
Information Networking and Applications (AINA 2006),Vienna
University of Technology, Austria, April 18 - 20, 2006 (Nejdl)
• 5th International Workshop on Agents and Peer-to-Peer
Computing (AP2PC 2006), 8 - 12 May 2006,Hakodate, Japan.
(Risse)
• 1st International Workshop on Managing Context Information
and Semantics in Mobile Environments (MCISME 2006) in
conjunction with the 7th International Conf erence on Mobile
Data Management (MDM‘06), Nara, Japan, May 9-12, 2006.
(Nejdl, Risse)
• Models of Trust for the Web, at the 15th Intl. World Wide Web
Conference, Edinburgh, Scotland, May 22 - 26, 2006 (Nejdl)
• 15th Intl. World Wide Web Conference, Semantic Web Track,
Edinburgh, Scotland, May 22 - 26, 2006 (Nejdl)
• 15th Intl. World Wide Web Conference, E* Applications Track,
Edinburgh, Scotland, May 22 - 26, 2006 (Nejdl)
• MTW Workshop at the WWW conference 2006, May, 23 -26,
2006 (Diederich)
• IEEE International Symposium on Circuits and Systems (ISCAS
2006). Special session on Advances in semantic multimedia
analysis for personalised content access, Island of Kos, Greece,
May 2006. (Olmedilla)
• Models of Trust for the Web Workshop (MTW) in conjunction
with the 15th International World Wide Web Conference,
Edinburgh, UK, May 2006. Co-Organizer (Olmedilla)
• Reasoning on the Web Workshop (RoW2006) in conjunction
with the 15th International World Wide Web Conference,
Edinburgh, UK, May 2006. (Olmedilla)
• IEEE International workshop on Context Aware Ubiquitous
Learning (CAUL 2006), Taichung, Taiwan June 5, 2006 (Nejdl)
• 1st Canadian Semantic Web Working Symposium 2006, June,
6, 2006. (Henze)
• 3rd European Semantic Web Conference, Budva, Montenegro,
June 11 - 14, 2006 (Diederich, Nejdl, Olmedilla, Henze, Stumme)
PROGRAM COMMITTEE MEMBERSHIPS PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
• Semantic Web Personalization auf der ESWC 2006, June,
11-14, 2006. (Henze)
• Co-Chair of the ESWC Workshop on Semantic Network
Analysis, Budva, Montenegro. 12. Juni 2006 (Stumme)
• Semantic Web Services Challenge 2006, Stanford University,
Phase I: March 13-14, 2006, Phase II: June 15-16, 2006 (Risse)
• Web-Based Systems Conference, June 20th, 2006, Dublin,
Ireland (Nejdl)4th Intl. Conference on Adaptive Hypermedia
and Adaptive Web-Based Systems, June 20 - June 23, 2006,
Dublin, Ireland (Nejdl)
• Adaptive Hypermedia and Adaptive Web-Based Systems 2006,
Dublin, Ireland, June 21 - 23, 2006 (Nejdl)
• Data Engineering Issues in E-Commerce and Services, Second
International Workshop, San Francisco, USA, June 26, 2006
(Nejdl)
• 4th International Workshop on Distributed and Mobile
Collaboration (DMC 2006), Manchester, UK, June 26-28, 2006
(Nejdl, Risse)
• 1st Int. Workshop on Semantic Technologies in Collaborative-
Applications at IEEE WETICE 2006, 26-28 June 2006. (Henze)
• 2nd Intl. Workshop on Data Engineering Issues in E-Commerce
,San Francisco, June 26-29, 2006 (Nejdl)
• ED-Media World Conference on Educational Multimedia, Hypermedia
and Telecommunications, June, 26-30, 2006. (Henze)
• TeaConc’2006 - Workshop on Teaching Concurrency, 27 June
2006 (Wagner)
• KnowledgeWeb PhD Symposium, Budva, Montenegro, June
2006. Scientific Advisor (Olmedilla)
• 3th European Semantic Web Conference, Lecture Notes in
Computer Science, Budva, Montenegro, June 2006. Springer.
(Olmedilla)
• European Semantic Web Conference Tutorial on Semantic
Web Policies: Where are we and What is still missing?, Budva,
Montenegro, June 2006. Presenter (Olmedilla)
• 4th Workshop on Principles and Practice of Semantic Web
Reasoning, Lecture Notes in Computer Science, Budva, Montenegro,
June 2006. Springer. Referee (Olmedilla)
• 26th International Conference on Distributed Computing
Systems, Lisboa, Portugal, July 4 - 7, 2006 (Nejdl)
• 21st National Conference on Artificial Intelligence (AAAI‘06)
Boston, Massachusetts, July 16-20, 2006 (Nejdl)
• Editorial Board of the 14th Intl. Conference on Conceptual
Structures (ICCS 2007), Aalborg, Dänemark, 16.-21. Juli 2006
(Stumme)
• ICINCO 2006 - International Conference on Informatics in
Control, Automation & Robotics, 1-5 August 2006 (Wagner)
• 1st Intl. Conference on Knowledge Science, Engineering and
Management, Guilin City, China, August 5 - 8, 2006 (Nejdl)
• 4th International IEEE Conference on Industrial Informatics,
16-18 August 2006, Singapore (Wagner)
• IFIP International Conference on Artificial Intelligence Applications
and Innovations, Santiago, Chile, 20.-22. Aug. 2006
(Stumme)
• The 3rd International Conference on Ubiquitous Intelligence
and Computing (UIC-06), Wuhan, China, Sep 2-6, 2006, (Nejdl)
• Mensch & Computer 2006, 3. bis 6. September 2006, Fachhochschule
Gelsenkirchen in Gelsenkirchen-Buer. (Henze)
• 1st Asian Semantic Web Conference (ASWC2006), Beijing,
China, September 3 - 7, 2006 (Nejdl)
•
8th International Conference on Data Warehousing and its
Applications (DaWaK 2006), Krakau, Polen, 4.-8. Sept. 2006
(Stumme)
91

92
PROJECTS PROGRAM COMMITTEE MEMBERSHIPS
• 7th International Conference on Knowledge Management,
Graz, September 5-7, 2006 (Nejdl)
• 6th International Conference on Knowledge Management,
Graz, Austria, September 6 - 8, 2006 (Nejdl)
• 4th Intl. Workshop on Databases, Information Systems and
Peer-to-Peer Computing, held at VLDB 2006, Seoul, Korea,
September 11, 2006 (Nejdl)
• 2nd VLDB Workshop on Ontology Based Techniques for
Databases and Information Systems, Seoul, Korea, 11. Sept.
2006 (Stumme)
• eLearning Fachtagung Informatik der GI, TU Darmstadt,
September 11 - 14, 2006 (Nejdl)
• 12th International Conference on Artificial Intelligence:
Methodology, Systems, Applications (AIMSA 2006), Varna,
Bulgarien, 13.-15. Sept. 2006 (Nejdl, Stumme)
• 10th European Conference on Research and Advanced
Technology for Digital Libraries 2006 (ECDL 2006), September
17-22, 2006, Alicante, Spain (Risse)
• 17th European Conference on Machine Learning/10th
Eurpean Conference on Principles and Practice of Knowledge
Discovery in Databases (ECML/PKDD 2006), Berlin, 18.-22.
Sept. 2006 (Stumme)
• 11th IEEE International Conference on, Emerging Technologies
and Factory Automation, September 20-22, Prague, Czech
Republic (Wagner)
• 1st Workshop on Digital Library Goes eScience: Perspectives
and Challenges. September, 21, 2006. Alicante, Spain;
Workshop in conjunction with ECDL 2006 (Risse, Niederée,
Organizing Committee)
• Semantic Web Education and Training Workshop, collocated
with the first Asian Semantic Web Conference (ASWC), Beijing,
China, September 2006. (Diederich)
• 7th IEEE International Conference on Grid Computing,
Barcelona, Spain, September 2006. (Olmedilla)
• Berliner XML Tage 2006 (BXML‘06), Berlin, Germany, September
2006. (Olmedilla)
• Workshop on Security and Trust Management (STM) in
conjunction with the 11th European Symposium On Research In
Computer Security (ESORICS), Hamburg, Germany, September
2006. (Olmedilla)
• Journal of Web Semantics. Elsevier, 2006. Reviewer (Olmedilla)
• Journal of Systems and Software. Elsevier, 2006. Reviewer
(Olmedilla)
• Journal of Web Semantics. Special Issue on Semantic Grid.
Elsevier, 2006. Reviewer (Olmedilla)
• ABIS 2006 - 14th Workshop on Adaptivity and User Modeling
in Interactive Systems, LWA Workshop Series, Hildesheim,
Germany, October 1-4, 2006, PC Chair (Herder)
• Crete, Greece - October 1-4, 2006, First European Conference
on Technology Enhanced Learning, PC Chair (Nejdl)
• 1st European Conference on Technology Enhanced Learning,
Crete, Greece, October 1 - 7, 2006 (Nejdl, Henze)
• 15th International Conference on Knowledge Engineering
and Knowledge Management (EKAW 2006), Prag, Tschechische
Republik, 2.-6. Okt. 2006 (Stumme)
• Bildung von Sozialen Netzwerken in Anwendungen der
Sozialen Software, Workshop at Informatik 2006, Dresden, 6.
Okt. 2006 (Stumme)
• 1st International Workshop on Applications of Semantic
Technologies, Workshop at Informatik 2006, Dresden, 6. Okt.
2006 (Stumme)
• The 7th International Conference on Web Information Systems
Engineering, Wuhan, China, October 23-26,2006, (Nejdl)
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
• E-Learn 2006, World Conference on ELearning in Corporate,
Government, Healthcare & Higher Education, Honolulu, Hawaii,
US, Oct 13-17, 2006 (Nejdl)
• International Conference on Web Information Systems and
Technologies, Wuhan, China, October 23-26,2006. (Henze)
• 5th International Conference on Ontologies, Databases and
Applications of Semantics, Montpellier, France, October 29
- November 3 2006 (Nejdl)
• 14th International Conference on Cooperative Information
System, Montpellier, France, October 29 - November 3 2006
(Nejdl)
• 2nd International Conference on Semantics, Knowledge and
Grid, Guilin, China, Oct 30 - Nov 01, 2006 (Nejdl)
• Joint International Workshop on Professional Learning, Competence
Development and Knowledge Management, Heraklion,
Greece, October 2006. Co-Organizer (Olmedilla)
• The 5th International Semantic Web Conference, Athens, GA,
USA, November 5 - 9, 2006, (Nejdl, Stumme)
• Semantic Web User Interaction auf der ISWC 2006, Nov., 5-9,
2006. (Henze)
• First European Conference on Technology Enhanced Learning
(EC-TEL 2006). Organizing Committee Member (Thaden)
• 2nd International Semantic Web Policy Workshop, (Nejdl)
• Semantic Desktop and Social Semantic Collaboration
Workshop, at the International Semantic Web Conference, 6
November 2006, Athens, US (Nejdl)
• 32nd Annual Conference of the IEEE Industrial Electronics
Society, Paris, France, November 7-10, 2006 (Wagner)
• Second International Conference on Rules and Rule Markup
Languages for the Semantic Web, Nov., 10-11, 2006 (Nejdl)
• Workshop on Information Retrieval in Peer-to-Peer Networks,
at the ACM 15th Conference on Information and Knowledge
Management, Arlington, US, November 11, 2006 (Nejdl)
• Workshop „Applications of Semantic Technologies“
(AST2006) (Thaden)
• ACM Workshop on Contextualized Attention Metadata:
Collecting, Managing and Exploiting Rich Usage Information,
at the 15th ACM Conference on Information and Knowledge
Management, November 11, 2006, Arlington, US (Nejdl)
• Workshop on Information Retrieval in Peer-to-Peer-Networks
(P2PIR 2006); Arlington, VA; November 11, 2006 (Risse)
• 31th Annual IEEE Conference on Local Computer Networks
(LCN 2006), Tampa, Florida, 14-16 November 2006. (Diederich)
• Semantics 2006 conference, Vienna, 28-30 November 2006.
(Diederich)
• RuleML International Conference Tutorial on Semantic Web
Policies: Where are we and What is still missing?, Athens,
Georgia, USA, November 2006. Presenter (Olmedilla)
• International Conference on Systems and Networks Communications
(ICSNC06), Tahiti, French Polynesia, November 2006.
(Olmedilla)
• 2nd Semantic Web Policy Workshop (SWPW) in conjunction
with the 5th International Semantic Web Conference, Athens,
Georgia, USA, November 2006. Co-Organizer (Olmedilla)
• 2nd International Workshop on Engineering Service-Oriented
Applications: Design and Composition (WESOA 2006), December
4th 2006, Chicago, USA (Risse)
• 4th International Conference on Service Oriented Computing
(ICSOC 2006); Chicago, USA, December 4-7, 2006 (Risse)
•
5th International Conference on Ontologies, Databases and
Applications of Semantics (ODBASE 2006), Montpellier, France,
2006 (Risse)

• International Conference on Parallel and Distributed Processing
and Applications (ISPA 2006), Lecture Notes in Computer
Science, Sorrento, Italy, December 2006. Springer. (Olmedilla)
• 3rd Italian Semantic Web Workshop on Semantic Web Applications
and perspectives (SWAP), Pisa, Italy, December 2006.
(Olmedilla)
• The IEEE / WIC / ACM Intl. Conference on Web Intelligence,
December 18-22, 2006, Hong Kong, China (Nejdl)
• ACM Journal on Transactions on Internet Technology. ACM,
2006. Reviewer (Olmedilla)
• IEEE Journal on Selected Areas in Communications, Special Issue
on Peer-to-Peer Communications and Applications (Chirita)
• Wiley SPE Journal on Software: Practice and Experience
(Chirita)
• Künstliche Intelligenz 2006.(Henze)
• International Network for Engineering Education and
Research, (Wagner)
• International Journal of Engineering Education, Editorial
Advisory Board (Wagner)
PROGRAM COMMITTEE MEMBERSHIPS PROJECTS
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
•Program
Committee Memberships 2007
• 33rd International Conference on Current Trends in Theory
and Practice of Computer Science (SOFWEM 2007), Harrachov,
Tschechische Republik, 20.-26. Jan. 2007 (Stumme)
• 5th Intl. Conference on Formal Concept Analysis, Clermont-
Ferrand, Frankreich, 12.-16. Februar 2007 (Stumme)
• International Conference on Semantic Web and Digital Libraries,
February 21-23, 2007, Bangalore, India (Nejdl)
• 3rd International Conference on Web Information Systems
and Technologies (WEBIST 2007), 3 - 6 March, 2007, Barcelona,
Spain (Risse)
• Workshop on Collaborative Knowledge Management,
Potsdam, 28. März 2007 (Stumme)
• 29th European Conference on Information Retrieval, Rome,
Italy, April 2-5, 2007 (Chirita)
• 12th International Conference on Databases for Advances
Applications, Bangkok, Thailand, April 9-12, 2007 (Nejdl)
• 3rd International Special Workshop on Databases for Next-
Generation Researchers (SWOD2007) in conjunction with the
23nd International Conference on Data Engineering (ICDE‘07),
April 2007, Istanbul, Turkey (Risse)
• 2nd International Workshop on Managing Context Information
and Semantics in Mobile Environments (MCISME 2007) in
conjunction with the 8th International Conference on Mobile
Data Management (MDM‘07), Mannheim, Germany, May 7-11,
2007 (Chirita, Risse)
• Member of the organising team of the WWW07 Workshop on
Social and Collaborative Construction of Structured Knowledge,
Banff, Kanada, 8. Mai 2007 (Stumme)
• 16th International World Wide Web Conference, May 8-12,
2007, Banff, Alberta, Canada, E* Applications Chair (Nejdl)
• 16th Intl. WWW Conference, Banff, Canada, 8.-12. Mai 2007
(Stumme)
• I3: Identity, Identifiers, Identifications Entity-Centric Approaches
to Information and Knowledge Management on the
Web, WWW2007, May 8.-12.2007 (Stecher)
• 2nd International Workshop on Adversarial Information
Retrieval held in conjunction with the 16th International World
Wide Web Conference, Banff, Canada, May 8-12, 2007 (Chirita)
• 5th ACS/IEEE International Conference on Computer Systems
and Applications (AICCSA 2007), May 13-16, 2007, Amman,
Jordan (Risse)
• 6th International Workshop on Agents and Peer-to-Peer Computing
(AP2PC 2007) in conjunction with 6th International Joint
Conference on Autonomous Agents and Multi Agent Systems,
Honolulu, Hawaii, May 14-18, 2007 (Risse)
• International Conference on Grid and Pervasive Computing
(GPC), Paris, France, May 2007. (Olmedilla)
• 2nd KnowledgeWeb PhD Symposium, Innsbruck, Austria,
2-7th June 2007.. Scientific Advisor. (Olmedilla) Organizing
Committee (Diederich)
• 4th Annual European Semantic Web Conference (ESWC),
Innsbruck, Austria, 2-7th June 2007. Organizing Committee
(Diederich)
• 4th European Semantic Web Conference, June 3-7, 2007,
Innsbruck, Austria (Nejdl)
• Workshop on Personalization, Policy and Usability Issues on
the Semantic Web, June 6, Innsbruck, Austria, http://www.
dai-labor.de/ESWC07/, held at the 4th European Semantic Web
Conference, (Nejdl)
•
2nd INFOSCALE International Conference on Scalable Information
Systems, Suzhou, China, June 6-8, 2007 (Chirita)
93

94
PROJECTS PROGRAM COMMITTEE MEMBERSHIPS
• APWeb/WAIM‘07, joint 9th Asia-Pacific Web Conference
and 8th International Conference on Web-Age Information
Management, June 16-18, 2007, HuangShan, China, (Nejdl)
• 5th International Workshop on Distributed and Mobile Collaboration
(DMC 2007) June 19th, 2007, Paris, France, held at
WETICE‘07, (Nejdl)
• User Modeling 2007, Corfu, Greece, June 25-29, 2007 (Herder)
• 4th European Semantic Web Conference, Lecture Notes in
Computer Science, Inssbruck, Austria, June 2007. Springer.
(Olmedilla)
• The 4th International Conference on Ubiquitous Intelligence
and Computing (UIC-07), Hong Kong, China, July 11-13, 2007,
(Nejdl)
• 22nd AAAI Conference on Artificial Intelligence, July 22-26,
2007, Vancouver, Canada, (Nejdl)
• 1st IEEE Intl. Conference on Research Challenges in Information
Science, Ouarzazate, Morocco, 23.-26. Juli 2007 (Stumme)
• International Workshops on Electronic Games and Personalized
eLearning Processes (EGAEL), Niigata, Japan, July 2007.
(Olmedilla)
• International Workshops on Electronic Games and Personalized
eLearning Processes (EGAEL), Nijmegen, The Netherlands,
July 2007. (Olmedilla)
• 4th International Conference on Autonomic and Trusted
Computing (ATC-07), Lecture Notes in Computer Science, Hong
Kong, China, July 2007. Springer. (Olmedilla)
• International Conference on Knowledge Management,
Vienna, Austria, August 27-28, 2007 (Nejdl)
• 5. eLearning Fachtagung Informatik 17-20. September 2007,
Siegen, Germany (Nejdl)
• Cyberworlds 2007, Oct 24-26, Hannover, Germany (Nejdl)
• 7th Intl. Conference on Peer-to-Peer Computing, September
2-5, 2007, Galway, Ireland (Nejdl)
• 18th International Conference on Database and Expert
Systems Applications, Regensburg, Germany, September 3-7,
2007 (Nejdl)
• IEEE 3rd International Conference on Intelligent Computer
Communication and Processing, September 6-8, 2007, Cluj-
Napoca, Romania (Nejdl)
• Second European Conference on Technology Enhanced Learning,
17-20 September 2007, Greece, http://www.ectel07.org/,
General Chair (Nejdl)
• 11th European Conference on Research and Advanced
Technology for Digital Libraries 2007 (ECDL 2007), Budapest,
Hungary,16-21 September 2007 (Risse)
• 4th International Conference on Grid Service Engineering and
Management (GSEM 2007), Leipzig, Germany, 24-26 September
2007 (Risse)
• Workshop on the Semantic Desktop held in conjunction with
the International iSemantics Conference, Graz, Austria, September,
2007 (Chirita)
• 15th International Conference on Cooperative Information
System, Lisbon, Portugal, October 28 - Nov 2, 2007 (Nejdl)
• 6th International Conference on Ontologies, Databases and
Applications of Semantics, Lisbon, Portugal, October 28 - Nov
2, 2007 (Nejdl)
• Second International Conference on Knowledge Science, Engineering
and Management, November 28-30, 2007, Melbourne,
Australia (Nejdl)
• 8th International Conference on Web Information Systems
Engineering (WISE 2007), Nancy, France, 3-7th December, 2007
(Risse)
FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
• Journal of Educational Technology and Society (endorsed
by IEEE Technical Committee on Learning Technology), 2007.
Executive Peer-Reviewer. (Olmedilla)
• Special Issue of Computers and Human Behavior Journal
on Electronic Games and Personalized eLearning Processes.
Elsevier, 2007. Editorial Board. (Olmedilla)
• Special Issue of Simulation & Gaming Journal on eGames and
Adaptive eLearning. A practical approach, 2007. Editorial Board.
(Olmedilla)
•
13th International Conference on Databases for Advances
Applications, Melbourne, Australia, March 19-22, 2008 (Nejdl)

FORSCHUNGSZENTRUM L3S · L3S RESEARCH CENTER
PROJECTS
95

Imprint:
Forschungszentrum L3S
Appelstrasse 9a
30167 Hannover / Germany
Tel.: +49 (0)511 762 - 17714
Fax: +49 (0)511 762 - 17779
E-Mail: info@L3S.de
http://www.L3S.de
Representatives:
Prof. Dr. Wolfgang Nejdl (Executive Director)
Dr. Uwe Thaden (Managing Director)
Consultancy:
Anna Stella Bonin
Bonin Communication Affairs
Heisenstr. 4
30167 Hannover
www.bonincomma.com
Design & Layout:
Dennis Kohlmetz
Design für elektronische Medien
Teichstr. 1
30449 Hannover / Germany
www.medienmogul.de
Photos:
Title: © Louise Gagnon - Fotolia,
Project page PEER-TO-PEER: © ptlee - Fotolia
Project page PEERTRUST: © Daniel Sainthorant - Fotolia
Project page KnowledgeWeb: © Orla - Fotolia
Project page REWERSE: © Patrick Hermans - Fotolia
D-Grid: www.caida.org/tools/visualization/walrus/gallery1/
News page PRO-LC: © Patrick Hermans - Fotolia
News page EC-TEL: © Maria Bielikova
All other photos: D. Kohlmetz

Forschungszentrum L3S
Appelstrasse 9a
30167 Hannover/Germany
contact: Dr. Uwe Thaden
phone.: +49. (0)511. 762-17713
fax: +49. (0)511. 762-17779
email: thaden@L3S.de
http://www.L3S.de