University of Applied Sciences, Institute of Structural Engineering

Dipl.-Ing. Ulrich Santa

Address:

email:      santa@ikiserver.boku.ac.at
                        
Office:   Institute of Structural Analysis
		Peter Jordan Strasse 82
		1190 Vienna
		Austria
		+43-1-47654-5266 (tel)
		+43-1-47654-5272 (fax modem)
		+43-1-47654-5292 (fax)

Research and Projects:

CSI(C&F): A Constraint Script Interpreter for Crisp and Fuzzy Sets - Master Thesis

DynaFLIP++: Dynamically adapted constraints for fuzzy multiple criteria optimization

StarFLIP++: A reusable iterative optimization environment with fuzzy constraints

YELLOW FISH: The Research Group Six: Technical Visualization and Animation

Fuzzy Constraint Satisfaction - Abstract

Real world problems are often overconstrained, ill-defined, or tolerate good though suboptimal solutions as long as those are found before a deadline. Such problems are often called partial constraint satisfaction problems (PCSPs). The model for PCSPs was initially inspired by classic constraint satisfaction methods. Another path leading to comparable notions and originating from fuzzy decision making is introduced in the present masters thesis, adding the following features to increase modeling capability: gradual satisfaction, priority, and compromises. Because of these additional degrees of freedom, fuzzy constraints must be fine-tuned for a certain task. However, such fine-tuning cannot be done for all possible instantiations of a problem, and thus is generally done on prototypical constraints. These templates are applied during run-time to a certain actual situation, i.e., dynamically adapted and applied only where necessary. This thesis describes issues arising from the existence of such dynamic constraints and how they are handled in the StarFLIP++ optimization libraries. Examples from a steelmaking scheduling application are given. Theoretical analysis and some initial experiments indicate that this method makes PCS ready to confront real world problems.

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last modified 1997-02-20