First International Conference on MOLDAVIAN RISKS – FROM ...

Recommendations

Info

<strong>First</strong> <strong>International</strong> <strong>Conference</strong> on MOLDAVIAN RISKS - FROM GLOBAL TO LOCAL SCALE 16-19 May 2012, Bacau, Romania DATA INCOHERENCE FOR COMBINATORIAL OPTIMIZATION PROBLEMS Gloria Cerasela Crisan 1 , Camelia-M. Pintea 2 , Camelia Chira 3 1 “Vasile Alecsandri” University of Bacau, Department of Mathematics, Informatics and Education Sciences 2 Tech Univ Cluj-Napoca, North Univ Center Baia-Mare, Faculty of Science 3 “Babeş-Bolyai” University of Cluj-Napoca, Department of Computer Science Corresponding author: Gloria Cerasela Crisan, ceraselacrisan@ub.ro Abstract: Data collections are fundamental in taking correct and on time decisions. In risk management, the coherence and the integrity of the problem’s data have great impact on the quality of the decision. If the data are biased, the applications that assist the manager can provide poor advices. The real-life problems reflect the complexity and heterogeneity of our modern society. The applications designed for solving them are therefore expensive, sophisticated and complex; inherently their results are hard to predict. This is why the influence of the data incoherence over the results is an extremely important issue to consider. The a-priori knowledge and its efficient handling are compulsory for modern, proactive strategy in problem solving. Knowing how a specific algorithm would behave when input data might be incoherent may help choosing between several algorithms athand to better deal with real-world problems. We here approach the influence of incoherent input data when solving Combinatorial Optimization Problems (COPs). Several new COP variants are defined and the stability of the corresponding solving methods under imperfect input data is investigated. Some parameters are defined and a parameterized complexity study is performed. Numerical experiments engage the well-known COP Travelling Salesman Problem in its standard form and a dynamic variant (with and without errors in the input data for both problem variants). All the problems are solved using Ant Colony Optimization algorithms, a biologically-inspired metaheuristic approach. The adaptation and the resilience of natural systems (Darwinian evolution, ant colony behaviour) suggest the same behaviour. We use a natural incoherence measure and we compare the applications results on correct and incoherent data. We modify the algorithms in order to store both the correct and the incoherent data. We extend our numerical experiments by coupling a new imperfection dimension: the uncertainty. The algorithms’ behaviour does not have a pattern: we observe stable, unstable, even catastrophic effects of input data incoherence. The paper generalizes a metaheuristic approach to a classical optimization problem when the data entry has some degree of incoherence. Key words: combinatorial optimization problems, parameterized complexity, data incoherence, heuristics, ant colony optimization. 60
<strong>First</strong> <strong>International</strong> <strong>Conference</strong> on MOLDAVIAN RISKS - FROM GLOBAL TO LOCAL SCALE 16-19 May 2012, Bacau, Romania RISKS RELATED TO EXTRACTION OF MINERALS AGGREGATES FROM RIVERS Stelian Cartacuzencu, Gabriel Lazar “Vasile Alecsandri” University of Bacau, Department of Environmental Engineering and Mechanical Engineering Corresponding author: Stelian Cartacuzencu, stelian_cartacuzencu@yahoo.com Abstract: Exploitation of mineral aggregates, mainly for roadbed and concrete, must assure the protection of environment factors and water quality, avoid of degradation of reserves and reduction of losses. Before starting the extraction process, the perimeters are delimited by boundaries whose overcome is not allowed. For the beginning the scraping is done to remove the superficial layer of earth. The leached material is usually used to restore the operation road through which the perimeter is accessed. Extraction is done from the water to shore, in longitudinal strips in continuously field. Excavated material is loaded directly into transportation vehicles or temporary storage deposits that not exceed the requirements of the working time of the day are made. By exploiting the mineral aggregates is desirable to assure the proper flow of rivers. After the reserves are depleted the working site is dismantled and the area is leveled to simulate the typical meadow landscape. Exploitation should be evaluated also in terms of flood management strategy. Operations should be performed by clogging and redesign the river bed in function of the influence of mineral aggregates exploitation. For proper exploitation the monitoring process should be applied during mineral aggregates exploitation, and the management decisions must be taken in order to promote perimeter regeneration. During the flood the actions will comply with the anti-flood plan and after, the perimeter will be cleansed by any materials brought by the flood. The preferential exploitation and the intermediate deposits that cannot be transported in one day having as effect creation of artificial elbow sand changes of river’s flow direction are some negative aspects regarding the management of mineral aggregates. The influence of the effects of faulty operation may impact breaks of banks, increased leachate thickness, increasing intensity of fluid erosion, and even flood stimulation. This paper shows the comparison of two exploitation cases: one made following the standards and other made in a faulty manner. The study wants to emphasize the need for good management of mineral aggregates, through a controlled process, in order to not brutally affect the environment. Key words: exploration, mineral aggregate, rivers flow, landscape, monitoring. 61
Page 1:
“VASILE ALECSANDRI” UNIVERSITY
Page 4 and 5:
Editors: Mioara Mandea, Gabriel Laz
Page 7 and 8:
First Inte
Page 9 and 10: First Inte
Page 59: First Inte
Page 111 and 112:
Sponsors of the conference Sodexo P
show all

First International Conference on MOLDAVIAN RISKS – FROM ...

Create successful ePaper yourself

Delete template?

Save as template?