Optimization of Display Structure using Search Algorithms

Rok Tomc (2010) Optimization of Display Structure using Search Algorithms. EngD thesis.

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Abstract

Display signs usually consist of lightbulbs organized into a matrix and are capable of dynamically displaying messages. Since not every message uses every available bulb, it is possible to optimize the production costs of such signs by reducing the number of bulbs on the sign. As with all optimization problems, we are confronted with the two opposing goals: a) we would like to use as few lightbulbs as possible and b) we require the displayed messages to be readable. In our thesis, we implemented several optimization algorithms for searching through state space of lightbulbs' configurations, trying to find the most optimal position of the lightbulbs. We estimate the optimality of the solution using a heuristical estimate which we developed and proposed especially for our approach. The proposed estimate estimates a quality with which a sign with certain configuration of lightbulbs is capable to represent a set of selected symbols. The estimate takes into consideration number of used bulbs and favors such configurations with less bulbs. Among the implemented algorithms, the harmony search has shown to be the most successful in this task. Its solutions had best quality values and on consecutive searches showed the most consistent behaviour.

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