1,084 research outputs found
Cheating for Problem Solving: A Genetic Algorithm with Social Interactions
We propose a variation of the standard genetic algorithm that incorporates
social interaction between the individuals in the population. Our goal is to
understand the evolutionary role of social systems and its possible application
as a non-genetic new step in evolutionary algorithms. In biological
populations, ie animals, even human beings and microorganisms, social
interactions often affect the fitness of individuals. It is conceivable that
the perturbation of the fitness via social interactions is an evolutionary
strategy to avoid trapping into local optimum, thus avoiding a fast convergence
of the population. We model the social interactions according to Game Theory.
The population is, therefore, composed by cooperator and defector individuals
whose interactions produce payoffs according to well known game models
(prisoner's dilemma, chicken game, and others). Our results on Knapsack
problems show, for some game models, a significant performance improvement as
compared to a standard genetic algorithm.Comment: 7 pages, 5 Figures, 5 Tables, Proceedings of Genetic and Evolutionary
Computation Conference (GECCO 2009), Montreal, Canad
Cheating for problem solving: a genetic algorithm with social interactions
We propose a variation of the standard genetic algorithm that incorporates social interaction between the individuals in the population. Our goal is to understand the evolutionary role of social systems and its possible application as a non-genetic new step in evolutionary algorithms. In biological populations, i.e. animals, even human beings and microorganisms, social interactions often affect the fitness of individuals. It is conceivable that the perturbation of the fitness via social interactions is an evolutionary strategy to avoid trapping into local optimum, thus avoiding a fast convergence of the population. We model the social interactions according to Game Theory. The population is, therefore, composed by cooperator and defector individuals whose interactions produce payoffs according to well known game models (prisoner's dilemma, chicken game, and others). Our results on Knapsack problems show, for some game models, a significant performance improvement as compared to a standard genetic algorithm
An Investigation Report on Auction Mechanism Design
Auctions are markets with strict regulations governing the information
available to traders in the market and the possible actions they can take.
Since well designed auctions achieve desirable economic outcomes, they have
been widely used in solving real-world optimization problems, and in
structuring stock or futures exchanges. Auctions also provide a very valuable
testing-ground for economic theory, and they play an important role in
computer-based control systems.
Auction mechanism design aims to manipulate the rules of an auction in order
to achieve specific goals. Economists traditionally use mathematical methods,
mainly game theory, to analyze auctions and design new auction forms. However,
due to the high complexity of auctions, the mathematical models are typically
simplified to obtain results, and this makes it difficult to apply results
derived from such models to market environments in the real world. As a result,
researchers are turning to empirical approaches.
This report aims to survey the theoretical and empirical approaches to
designing auction mechanisms and trading strategies with more weights on
empirical ones, and build the foundation for further research in the field
Cheating for problem solving: a genetic algorithm with social interactions
We propose a variation of the standard genetic algorithm that incorporates social interaction between the individuals in the population. Our goal is to understand the evolutionary role of social systems and its possible application as a non-genetic new step in evolutionary algorithms. In biological populations, i.e. animals, even human beings and microorganisms, social interactions often affect the fitness of individuals. It is conceivable that the perturbation of the fitness via social interactions is an evolutionary strategy to avoid trapping into local optimum, thus avoiding a fast convergence of the population. We model the social interactions according to Game Theory. The population is, therefore, composed by cooperator and defector individuals whose interactions produce payoffs according to well known game models (prisoner's dilemma, chicken game, and others). Our results on Knapsack problems show, for some game models, a significant performance improvement as compared to a standard genetic algorithm
Computation and analysis of evolutionary game dynamics
Biological processes are usually defined based on the principles of replication, mutation, competition, adaption, and evolution. In evolutionary game theory, such a process is modeled as a so-called evolutionary game, which not only provides an alternative interpretation of dynamical equilibrium in terms of the game nature of the process, but also bridges the stability of the biological process with the Nash equilibrium of the evolutionary game. Computationally, the evolutionary game models are described in terms of inverse and direct games, which are estimating the payoff matrix from data and computing the Nash equilibrium of a given payoff matrix respectively. We discuss the necessary and sufficient conditions for the Nash equilibrium states, and derive the methods for both inverse and direct games in this thesis. The inverse game is solved by a non-parametric smoothing method and penalized least squares method, while different schemes for the computation of the direct game are proposed including a specialized Snow-Shapley algorithm, a specialized Lemke-Howson algorithm, and an algorithm based on the solution of a complementarity problem on a simplex. Computation for the sparsest and densest Nash equilibria is investigated. We develop a new algorithm called dual method with better performance than the traditional Snow-Shapley method on the sparse and dense Nash equilibrium searching. Computational results are presented based on examples. The package incorporating all the schemes, the Toolbox of Evolution Dynamics Analysis (TEDA), is described
Modeling Daily Fantasy Basketball
Daily fantasy basketball presents interesting problems to researchers due to the extensive amounts of data that needs to be explored when trying to predict player performance. A large amount of this data can be noisy due to the variance within the sport of basketball. Because of this, a high degree of skill is required to consistently win in daily fantasy basketball contests. On any given day, users are challenged to predict how players will perform and create a lineup of the eight best players under fixed salary and positional requirements. In this thesis, we present a tool to assist daily fantasy basketball players with these tasks. We explore the use of several machine learning techniques to predict player performance and develop multiple approaches to approximate optimal lineups. We then compare each different heuristic and lineup creation combination, and show that our best combinations perform much better than random lineups. Although creating provably optimal lineups is computationally infeasible, by focusing on players in the Pareto front between performance and cost we can reduce the search space and compute near optimal lineups. Additionally, our greedy and evolutionary lineup search methods offer similar performance at a much smaller computational cost. Our analysis indicates that due to how player salaries are structured, it is generally preferred to construct a lineup consisting of a few stars and filling out the rest of the roster with average to mediocre players than to construct a lineup where all players are expected to perform about the same. Through these findings we hope that our research can serve as a future baseline towards developing an automated or semi-automated tool to optimize daily fantasy basketball
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