Showing papers by "Sergio Guadarrama published in 2009"

A new approach to fuzzy location of cephalometric landmarks in craniofacial superimposition

Abstract: Craniofacial superimposition is the second stage of a complex forensic technique that aims to identify a missing person from a photograph (or video shot) and the skull found. This spe- cific task is devoted to find the most appropriate pose of the skull model to be projected onto the photograph. The process is guided by a number of landmarks identified both in the skull (craniometric landmarks) and in the face (cephalometric landmarks). In this con- tribution we extend our previous genetic algorithm-based approach to the problem by considering the uncertainty involved in the location of the cephalometric landmarks and its influence in the matching be- tween these landmarks and the craniometric ones. The new proposal is tested over two instances of a real case solved by the Physical An- thropology lab at the University of Granada (Spain). Keywords— Craniofacial superimposition, fuzzy landmarks, ge- netic algorithms, image registration.

Computing with Actions: The case of driving a car in a simulated car race

Abstract: Describing and modeling a complex system is very hard and time consuming, so, we propose to use a linguistic approach introduced by Zadeh. By taking a linguistic approach we can use linguistic variables and approximate rules to characterize approxi- mately phenomenons which are too complex or too ill-defined to be done in numerical terms. Starting from the results obtained in our previous works, in this paper we propose to decompose complex behaviors in simple be- haviors, and context dependent rules for the behaviors coordination, which are described by set of fuzzy rules. The use of fuzzy rules for behavior coordination and behavior description has allowed us to have a shared framework that makes easy to develop and to compute with linguistic descriptions of actions. We propose to use a mixture of competitive and cooperative co- evolutionary algorithms to manage the big search space and tackle a complex and decomposable problem. We use the Fuzzy-IEEE 2007 Car Racing Competition as an ex- ample of a problem that allows to show the benefits of our approach. In the example presented the results obtained are better and the flex- ibility is increased with respect to previous works. Keywords— Computing with Words, Computing with Actions, Fuzzy Linguistic Descriptions, Fuzzy Controllers, Co-evolutionary Algorithms, Behavior coordination.

Evaluating premises, partial consequences and partial hypotheses ∗

Abstract: To evaluate premises, consequences and hypotheses, on this paper relevance and support ratios are defined for each of them. This allows to distinguish consequences based on the num- ber of premises that support them, and also to reduce the set of premises while maintaining the same consequences. Since the re- lation between premises and hypotheses is, in some sense, similar to the relation between consequences and premises, analogous ratios are defined for hypotheses and premises. Keywords— Conjectures, Consequences, Hypotheses, Relevance, Support.