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These simple parameters significantly affect broker behaviour. For example, by maximis<strong>in</strong>g the expertise<br />

partition, we can achieve more value of the broker as an expert. By <strong>in</strong>creas<strong>in</strong>g the value of the retrieval cost<br />

necessary for replication, we reduce the number of brokers replicat<strong>in</strong>g a given abstract, thus, potentially<br />

reduc<strong>in</strong>g whole amount of the “expert” brokers with duplicated expertise.<br />

All abstracts that are obta<strong>in</strong>ed as query results and recognised as valuable after presentation to users, are cached<br />

locally, at least <strong>in</strong> the wide view group, if the cost of their retrieval is higher than some threshold. The LRU<br />

(Least Recently Used) algorithm is used to update the cache. If there are many similar abstracts to a new one <strong>in</strong><br />

the expertise group, and the rank<strong>in</strong>g scores are high enough, the new abstract is <strong>in</strong>cluded <strong>in</strong>to the expertise<br />

group.<br />

Add<strong>in</strong>g a New Broker<br />

A broker consists of a software and a database. The parts that differ one broker from another one are setup<br />

parameters and the database. Setup parameters must be provided by the owner of the broker. However, to make<br />

a new broker work<strong>in</strong>g, we have to supply it with knowledge of the world, which is the content of the database.<br />

To do this, we can “transplant” a database from any work<strong>in</strong>g broker.<br />

In the worst case, the donor broker is topologically far from the receiver and there is noth<strong>in</strong>g common between<br />

the corporate user profile of the owner of the donor and the owner of the receiver. This means that:<br />

1. The database <strong>in</strong><strong>format</strong>ion about the retrieval costs is wrong. This leads to <strong>in</strong>effective query rout<strong>in</strong>g.<br />

2. The database is irrelevant to the local users. This leads to remote process<strong>in</strong>g of the most of queries.<br />

However, <strong>in</strong> both cases the situation improves gradually, with the broker updat<strong>in</strong>g its cache and, thus, adapt<strong>in</strong>g<br />

to the changed conditions. To achieve better results <strong>in</strong> a shorter time, one should borrow the database from as<br />

“close” a broker as possible. We mean “close” <strong>in</strong> topological and corporate user profile aspects.<br />

Another way to start a new broker is to supply it with address of the closest function<strong>in</strong>g broker for default query<br />

rout<strong>in</strong>g. In this case, for the first time, most of the queries will be re-routed to that one until the new broker<br />

accumulates enough knowledge for <strong>in</strong>dependent function<strong>in</strong>g.<br />

What Can What’sHot Do for Its Users<br />

Suppose only one organisation is runn<strong>in</strong>g a broker of this type. The broker enables people to transparently share<br />

their expert knowledge about the availability and value of the resources, thus reduc<strong>in</strong>g the time and cost of<br />

searchs for <strong>in</strong><strong>format</strong>ion. The communication cost of a search is reduced because many queries are resolved<br />

locally. The broker <strong>in</strong> this case works as a very large dynamic searchable corporate hot list filled with useful<br />

URLs which people can transparently share. People do create such hot lists at the moment, but they do it<br />

manually, cannot search them and do not transparently share them.<br />

Suppose that there is a deployed network of the brokers. Given that each broker can ma<strong>in</strong>ta<strong>in</strong> <strong>in</strong><strong>format</strong>ion about<br />

thousands of other brokers, the overall <strong>in</strong>dex<strong>in</strong>g capacity of this network is enormous. A function<strong>in</strong>g network<br />

composes a k<strong>in</strong>d of serachable space and enables people to publish their materials with<strong>in</strong> this space. This is a<br />

remarkable decentralised way of publish<strong>in</strong>g where everyone can publish anyth<strong>in</strong>g, but only the best materials<br />

will be replicated widely and f<strong>in</strong>d their way to the mass consumer.<br />

Acknowledgements<br />

The work reported <strong>in</strong> this paper has been funded <strong>in</strong> part by the Co-operative Research Centres Program through<br />

the Department of the Prime M<strong>in</strong>ister and Cab<strong>in</strong>et of the Commonwealth Government of Australia.

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