Semantically-Oriented Mutation Operator in Cartesian Genetic Programming for Evolutionary Circuit Design

Despite many successful applications, Cartesian Genetic Programming (CGP) suffers from limited scalability, especially when used for evolutionary circuit design. Considering the multiplier design problem, for example, the 5x5-bit multiplier represents the most complex circuit evolved from a randomly generated initial population. The efficiency of CGP highly depends on the performance of the point mutation operator, however, this operator is purely stochastic. This contrasts with the recent developments in Genetic Programming (GP), where advanced informed approaches such as semantic-aware operators are incorporated to improve the search space exploration capability of GP. In this paper, we propose a semantically-oriented mutation operator (SOMO) suitable for the evolutionary design of combinational circuits. SOMO uses semantics to determine the best value for each mutated gene. Compared to the common CGP and its variants as well as the recent versions of Semantic GP, the proposed method converges on common Boolean benchmarks substantially faster while keeping the phenotype size relatively small. The successfully evolved instances presented in this paper include 10-bit parity, 10+10-bit adder and 5x5-bit multiplier. The most complex circuits were evolved in less than one hour with a single-thread implementation running on a common CPU.Comment: Accepted for Genetic and Evolutionary Computation Conference (GECCO '20), July 8--12, 2020, Canc\'un, Mexic

Programação genética aplicada à identificação de acidentes de uma usina nuclear PWR

This work presentes the results of the study that evaluated the efficiency of the evolutionary computation algorithm genetic programming as a technique for the optimization and feature generation at a pattern recognition system for the diagnostic of accidents in a pressurized water reactor nuclear power plant. The foundations of a typical pattern recognition system, the state of the art of genetic programming and of similar accident/transient diagnosis systems at nuclear power plants are also presented. Considering the set of the time evolution of seventeen operational variables for the three accident scenarios approached, plus normal condition, the task of genetic programming was to evolve non-linear regressors with combination of those variables that would provide the most discriminatory information for each of the events. After exhaustive tests with plenty of variable associations, genetic programming was proven to be a methodology capable of attaining success rates of, or very close to, 100%, with quite simple parametrization of the algorithm and at very reasonable time, putting itself in levels of performance similar or even superior as other similar systems available in the scientific literature, while also having the additional advantage of requiring very little pretreatment (sometimes none at all) of the dataNeste trabalho são apresentados os resultados do estudo que avaliou a performance do algoritmo de computação evolucionária programação genética como ferramenta de otimização e geração de atributos em um sistema de reconhecimento de padrões para identificação e diagnóstico de acidentes de uma usina nuclear com reator de água pressurizada. São apresentados ainda as bases de um sistema de reconhecimento de padrões, o estado da arte da programação genética e de sistemas similares de diagnóstico de acidentes e transientes de usinas nucleares. Dentro do conjunto da evolução temporal de 17 variáveis operacionais dos três acidentes/transientes considerado, além da condição normal, a função da programação genética foi evoluir regressores não lineares de combinações dessas variáveis que fornecessem o máximo de informação discriminatória para cada um dos eventos. Após testes exaustivos com diversas associações de variáveis, a programação genética se mostrou uma metodologia capaz de fornecer taxas de acerto de, ou muito próximas de, 100%, com parametrizações do algoritmo relativamente simples e em tempo de treinamento bastante razoável, mostrando ser capaz de fornecer resultados compatíveis e até superiores a outros sistemas disponíveis na literatura, com a vantagem adicional de requerer pouco (e muitas vezes nenhum) pré-tratamento nos dados