We propose a new approach to solve shape optimization problems based on estimation of distributio... more We propose a new approach to solve shape optimization problems based on estimation of distribution algorithms (EDA’s) combined with information from the physical problem (finite elements connectivities). Our algorithm improves exploration capacity by the regularization of the probability vectors. Therefore, the number of small holes in the structure is decreased as well as unconnected elements (elements connected at a vertex whose sides are not shared). We use a multiobjective approach to find Pareto solutions for two design goals: minimum weight and minimum displacement at some specific nodes. The solutions must fulfill three design constraints: maximum permissible Von Misses Stress, requirement of connectedness by sides in elements, and designs with small holes are not allowed.
El problema de síntesis de mecanismos consiste en determinar las dimensiones de los eslabones a f... more El problema de síntesis de mecanismos consiste en determinar las dimensiones de los eslabones a fin de que éstos puedan completar una tarea, la cual es definida por el posicionamiento en un conjunto de puntos denominados puntos de precisión. En este trabajo se aborda este problema como un ejercicio de optimización, que minimiza la distancia entre la posición de un mecanismo propuesto y los puntos de precisión, tomando como variables de decisión las dimensiones del mecanismo, su sistema coordenado relativo y parámetros que determinan la velocidad del mismo y la posición inicial. La propuesta final es un algoritmo para el diseño automatizado de mecanismos que cumplan en lo mayor posible con la tarea deseada. Se utilizó un Algoritmo de Estimación de Distribución (EDA, por sus siglas en inglés), el cual aproxima el óptimo mediante muestreos subsecuentes de una distribución Normal multivariada, donde cada muestra representa una propuesta de un mecanismo. Después, se simula y se mide la d...
Una nueva manera de modelar dependencias probabilísticas en el algoritmo de Maximización de Infor... more Una nueva manera de modelar dependencias probabilísticas en el algoritmo de Maximización de Información Mutua mediante Clústeres de Entrada (MIMIC) es presentada. Mediante cópulas es posible separar la estructura de dependencia de las distribuciones marginales en una distribución conjunta. El uso de cópulas como un mecanismo para modelar distribuciones y su aplicación a MIMIC es ilustrado en la función de prueba Rosenbrock.
We introduce the PESO (Particle Evolutionary Swarm Optimization) algorithm for solving single obj... more We introduce the PESO (Particle Evolutionary Swarm Optimization) algorithm for solving single objective constrained optimization problems. PESO algorithm proposes two perturbation operators: “c-perturbation” and “m-perturbation”. The goal of these operators is to prevent premature convergence and the poor diversity issues observed in Particle Swarm Optimization (PSO) implementations. Constraint handling is based on simple feasibility rules, enhanced with a dynamic ε-tolerance
In this paper we propose an approach based on a genetic algorithm (GA) to design combinationallog... more In this paper we propose an approach based on a genetic algorithm (GA) to design combinationallogic circuits in which the objective is to minimize their total number of gates.Our results compare favorably against those produced by human designers and even anotherGA-based approach. We also briefly analyze the solutions found by the GA trying tofind some clues on how it reduces
This article introduces the circuit design problem as a synthesis procedure. An evolutionary tech... more This article introduces the circuit design problem as a synthesis procedure. An evolutionary technique denominated Genetic Programing (GP) is proposed as the main engine for the synthesis of logic circuits. This article argues that the synthesis of circuits using bottomup procedures ...
Abstract. In this paper, we propose a case-based reason-ing scheme in which we extract domain kno... more Abstract. In this paper, we propose a case-based reason-ing scheme in which we extract domain knowledge (in the form of design patterns) from a genetic algorithm used to optimize combinational logic circuits at the gate level. Such information is used in two ways: first, we show how ...
We propose a new approach to solve shape optimization problems based on estimation of distributio... more We propose a new approach to solve shape optimization problems based on estimation of distribution algorithms (EDA’s) combined with information from the physical problem (finite elements connectivities). Our algorithm improves exploration capacity by the regularization of the probability vectors. Therefore, the number of small holes in the structure is decreased as well as unconnected elements (elements connected at a vertex whose sides are not shared). We use a multiobjective approach to find Pareto solutions for two design goals: minimum weight and minimum displacement at some specific nodes. The solutions must fulfill three design constraints: maximum permissible Von Misses Stress, requirement of connectedness by sides in elements, and designs with small holes are not allowed.
El problema de síntesis de mecanismos consiste en determinar las dimensiones de los eslabones a f... more El problema de síntesis de mecanismos consiste en determinar las dimensiones de los eslabones a fin de que éstos puedan completar una tarea, la cual es definida por el posicionamiento en un conjunto de puntos denominados puntos de precisión. En este trabajo se aborda este problema como un ejercicio de optimización, que minimiza la distancia entre la posición de un mecanismo propuesto y los puntos de precisión, tomando como variables de decisión las dimensiones del mecanismo, su sistema coordenado relativo y parámetros que determinan la velocidad del mismo y la posición inicial. La propuesta final es un algoritmo para el diseño automatizado de mecanismos que cumplan en lo mayor posible con la tarea deseada. Se utilizó un Algoritmo de Estimación de Distribución (EDA, por sus siglas en inglés), el cual aproxima el óptimo mediante muestreos subsecuentes de una distribución Normal multivariada, donde cada muestra representa una propuesta de un mecanismo. Después, se simula y se mide la d...
Una nueva manera de modelar dependencias probabilísticas en el algoritmo de Maximización de Infor... more Una nueva manera de modelar dependencias probabilísticas en el algoritmo de Maximización de Información Mutua mediante Clústeres de Entrada (MIMIC) es presentada. Mediante cópulas es posible separar la estructura de dependencia de las distribuciones marginales en una distribución conjunta. El uso de cópulas como un mecanismo para modelar distribuciones y su aplicación a MIMIC es ilustrado en la función de prueba Rosenbrock.
We introduce the PESO (Particle Evolutionary Swarm Optimization) algorithm for solving single obj... more We introduce the PESO (Particle Evolutionary Swarm Optimization) algorithm for solving single objective constrained optimization problems. PESO algorithm proposes two perturbation operators: “c-perturbation” and “m-perturbation”. The goal of these operators is to prevent premature convergence and the poor diversity issues observed in Particle Swarm Optimization (PSO) implementations. Constraint handling is based on simple feasibility rules, enhanced with a dynamic ε-tolerance
In this paper we propose an approach based on a genetic algorithm (GA) to design combinationallog... more In this paper we propose an approach based on a genetic algorithm (GA) to design combinationallogic circuits in which the objective is to minimize their total number of gates.Our results compare favorably against those produced by human designers and even anotherGA-based approach. We also briefly analyze the solutions found by the GA trying tofind some clues on how it reduces
This article introduces the circuit design problem as a synthesis procedure. An evolutionary tech... more This article introduces the circuit design problem as a synthesis procedure. An evolutionary technique denominated Genetic Programing (GP) is proposed as the main engine for the synthesis of logic circuits. This article argues that the synthesis of circuits using bottomup procedures ...
Abstract. In this paper, we propose a case-based reason-ing scheme in which we extract domain kno... more Abstract. In this paper, we propose a case-based reason-ing scheme in which we extract domain knowledge (in the form of design patterns) from a genetic algorithm used to optimize combinational logic circuits at the gate level. Such information is used in two ways: first, we show how ...
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