Algoritmos evolutivos : Estudio de escalabilidad sobre el problema 3-SAT

En este trabajo se investiga la influencia del tamaño del problema en la performance de los Algoritmos Evolutivos (AEs), utilizados para resolver un conocido problema NP-completo: el 3-SAT. Para ello se ha realizado una amplia recopilación de diferentes variantes de AEs, desarrollados para mejorar la calidad de los resultados. También, se describen los AEs usados para analizar el comportamiento de los mismos frente a problemas de tamaño creciente, tomados de benchmarks internacionales. Este estudio también incluye el análisis de la incorporación de distribución y paralelismo en la resolución del problema, como caminos alternativos para resolverlo en menor tiempo.Eje: Sistemas de información y MetaheurísticaRed de Universidades con Carreras en Informática (RedUNCI

A Comparative Study of Randomized Constraint Solvers for Random-Symbolic Testing

The complexity of constraints is a major obstacle for constraint-based software verification. Automatic constraint solvers are fundamentally incomplete: input constraints often build on some undecidable theory or some theory the solver does not support. This paper proposes and evaluates several randomized solvers to address this issue. We compare the effectiveness of a symbolic solver (CVC3), a random solver, three hybrid solvers (i.e., mix of random and symbolic), and two heuristic search solvers. We evaluate the solvers on two benchmarks: one consisting of manually generated constraints and another generated with a concolic execution of 8 subjects. In addition to fully decidable constraints, the benchmarks include constraints with non-linear integer arithmetic, integer modulo and division, bitwise arithmetic, and floating-point arithmetic. As expected symbolic solving (in particular, CVC3) subsumes the other solvers for the concolic execution of subjects that only generate decidable constraints. For the remaining subjects the solvers are complementary

Cellular memetic algorithms

This work is focussed on the development and analysis of a new class of algorithms, called cellular memetic algorithms (cMAs), which will be evaluated here on the satisfiability problem (SAT). For describing a cMA, we study the effects of adding specific knowledge of the problem to the fitness function, the crossover and mutation operators, and to the local search step in a canonical cellular genetic algorithm (cGA). Hence, the proposed cMAs are the result of including these hybridization techniques in different structural ways into a canonical cGA. We conclude that the performance of the cGA is largely improved by these hybrid extensions. The accuracy and efficiency of the resulting cMAs are even better than those of the best existing heuristics for SAT in many cases.Facultad de Informátic

Algoritmos evolutivos : Estudio de escalabilidad sobre el problema COUNTSAT

En este trabajo se investiga la influencia del tamaño del problema en la performance de los Algoritmos Evolutivos (AEs), utilizados para resolver una variante NP-difícil del problema MAXSAT denominada COUNTSAT. Para ello se ha realizado una recopilación de diferentes tipos de AEs, desarrollados para mejorar la calidad de los resultados. También, se describen los AEs usados para analizar el comportamiento de los mismos frente a problemas de tamaño creciente, tomados de benchmarks internacionales. Este estudio incluye el análisis de la incorporación de distribución y paralelismo en la resolución del problema, como caminos alternativos para encontrar el óptimo con menor esfuerzo numérico.Eje: V - Workshop de agentes y sistemas inteligentesRed de Universidades con Carreras en Informática (RedUNCI

Algoritmos evolutivos : Estudio de escalabilidad sobre el problema COUNTSAT

En este trabajo se investiga la influencia del tamaño del problema en la performance de los Algoritmos Evolutivos (AEs), utilizados para resolver una variante NP-difícil del problema MAXSAT denominada COUNTSAT. Para ello se ha realizado una recopilación de diferentes tipos de AEs, desarrollados para mejorar la calidad de los resultados. También, se describen los AEs usados para analizar el comportamiento de los mismos frente a problemas de tamaño creciente, tomados de benchmarks internacionales. Este estudio incluye el análisis de la incorporación de distribución y paralelismo en la resolución del problema, como caminos alternativos para encontrar el óptimo con menor esfuerzo numérico.Eje: V - Workshop de agentes y sistemas inteligentesRed de Universidades con Carreras en Informática (RedUNCI

Smallest-Small-World Cellular Harmony Search for Optimization of Unconstrained Benchmark Problems

We presented a new hybrid method that combines cellular harmony search algorithms with the Smallest-Small-World theory. A harmony search (HS) algorithm is based on musical performance processes that occur when a musician searches for a better state of harmony. Harmony search has successfully been applied to a wide variety of practical optimization problems. Most of the previous researches have sought to improve the performance of the HS algorithm by changing the pitch adjusting rate and harmony memory considering rate. However, there has been a lack of studies to improve the performance of the algorithm by the formation of population structures. Therefore, we proposed an improved HS algorithm that uses the cellular automata formation and the topological structure of Smallest-Small-World network. The improved HS algorithm has a high clustering coefficient and a short characteristic path length, having good exploration and exploitation efficiencies. Nine benchmark functions were applied to evaluate the performance of the proposed algorithm. Unlike the existing improved HS algorithm, the proposed algorithm is expected to have improved algorithmic efficiency from the formation of the population structure

General Purpose Cellular Automata Programming

As cellular automata are becoming popular in many research areas, the need for an easy-to-use system for cellular automata programming is becoming greater. Traditionally, cellular automata transition functions were manually depicted in a tabular format, which is often time-consuming and error prone. A more promising approach is to design a general-purpose cellular automata programming environment. In this thesis, a new cellular automata simulation environment, jTrend, is introduced. jTrend was developed on the Java platform for cellular automata exploratory research. With a built-in high-level programming language and an easy-to-use graphical user interface, jTrend has become one of the most powerful cellular automata simulators, and can be used for most one- and two-dimensional cellular automata simulations. The object-oriented design and performance optimization techniques used in jTrend provide high flexibility and fast simulation speed. jTrend has been used to study some real world problems in cellular automata. Solutions for two important problems, bubble sort and satisfiability (SAT), have been implemented using jTrend. Their experiment results suggest that it may be advantageous to solve problems using cellular automata, and jTrend provides a foundation to test such ideas

Proceedings of the First NASA Formal Methods Symposium

Topics covered include: Model Checking - My 27-Year Quest to Overcome the State Explosion Problem; Applying Formal Methods to NASA Projects: Transition from Research to Practice; TLA+: Whence, Wherefore, and Whither; Formal Methods Applications in Air Transportation; Theorem Proving in Intel Hardware Design; Building a Formal Model of a Human-Interactive System: Insights into the Integration of Formal Methods and Human Factors Engineering; Model Checking for Autonomic Systems Specified with ASSL; A Game-Theoretic Approach to Branching Time Abstract-Check-Refine Process; Software Model Checking Without Source Code; Generalized Abstract Symbolic Summaries; A Comparative Study of Randomized Constraint Solvers for Random-Symbolic Testing; Component-Oriented Behavior Extraction for Autonomic System Design; Automated Verification of Design Patterns with LePUS3; A Module Language for Typing by Contracts; From Goal-Oriented Requirements to Event-B Specifications; Introduction of Virtualization Technology to Multi-Process Model Checking; Comparing Techniques for Certified Static Analysis; Towards a Framework for Generating Tests to Satisfy Complex Code Coverage in Java Pathfinder; jFuzz: A Concolic Whitebox Fuzzer for Java; Machine-Checkable Timed CSP; Stochastic Formal Correctness of Numerical Algorithms; Deductive Verification of Cryptographic Software; Coloured Petri Net Refinement Specification and Correctness Proof with Coq; Modeling Guidelines for Code Generation in the Railway Signaling Context; Tactical Synthesis Of Efficient Global Search Algorithms; Towards Co-Engineering Communicating Autonomous Cyber-Physical Systems; and Formal Methods for Automated Diagnosis of Autosub 6000