Constructing q-cyclic games with unique prefixed e quilibrium

In this work we construct a wide family of q-cyclic n-person games (Marchi and Quintas (1983)) with unique prefixed Nash equilibrium points. We extend the constructions given for bimatrix games by Marchi and Quintas (1987) and Quintas (1988 a). We prove the uniqueness of equilibrium for a wide family of completely mixed q-cyclic game and also for a family of not completely mixed q-cyclic game, with each players having n strategies, being only m (m<n) of them active strategies.Fil: Alaniz, Sara Aida. Universidad Nacional de San Luis. Facultad de Ingeniería y Ciencias Económico Sociales; ArgentinaFil: Quintas, Luis Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis ; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Departamento de Matemáticas; Argentin

Computing power indices in weighted majority games

Power indices methodology of weighted majority game is widely used to measure a priori voting power of members of a committee. In this paper we present a computer implementation of the main power indices: Shapley-Shubik, Banzhaf, Johnston, Deegan-Packel and the Holler- Packel power indices. This computer implementation allows comparing the different indices. The system was developed for multiplataform: Linux and Windows. We compute the power indices for two examples and analyze its results.Eje: VI Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

The Microsoft vs. Netscape browser’s war: A game theory based analysis

During 1996 the world’s attention was captured by the litigation posed by the United States’ government against Microsoft, blaming the latter of abusive use of its monopoly power in order to win what was known as the “browser’s war”. This paper presents the previous scenario to the web browser’s battle carried out by Microsoft and Netscape, analyzing both firm’s strategies in a short and also in a long term horizon game. The study provided is based on game theory tools and attempts to give a model that explains the firms’ behavior. Although the presented model is quite simple, it accurately explains the strategic interaction between the firms and its predictions fits with the actual results.Eje: V - Workshop de agentes y sistemas inteligentesRed de Universidades con Carreras en Informática (RedUNCI

Computer implementation of bankruptcy rules

In this paper we describe a computer system that calculates allocation to claims according to two kinds of bankruptcy rules. The first kind implemented are those whose results corresponds to the classical solutions of game theory: The Talmud rule, the Proportional rule, the Adjusted Proportional rule, the Constrained Equal Awards rule and the Random Arrival rule. The second type implemented generates assignations to claims that have no correspondence with the classical results, they are: Piniles´ rule, the Constrained Egalitarian rule and Constrained Equal Losses rule. This computer system was developed in order to compute the different allocations to claims in Allocation problems, distribution problems and Assignment problems for real cases and to be used in education of game theory and decision problems. The system generates numerical and graphical results. It allows comparisons between the numerical results and their graphic representations. It also allows the exportation of the different outputs to any windows application.Eje: V - Workshop de agentes y sistemas inteligentesRed de Universidades con Carreras en Informática (RedUNCI

Visualization of 3-dimensional bargaining problems

This paper presents a visualization in three dimensions of the classical solutions of the bargaining problem for 3 agents. It provides a helpful tool for game theorists, economists and other researchers and professionals in these areas in order to visualize and compare the solutions over a wide family of bargaining problems and gain intuition about general results. The theory of bargaining, a branch of the Cooperative Game Theory, tries to find reasonable solutions when two or more agents have to decide over a wide variety of possible agreements among a family of conflictive situations. There are a lot of parameters entering in the description of the problem and also a large number of appealing solutions that have been defined in the literature. In order to compare and analize the behavior of different solutions for the different situations, is very important to have a visualization tool.Eje: Computación gráficaRed de Universidades con Carreras en Informática (RedUNCI

Two popultions, two strategies and a conflict: an evolutionary approach

In this paper we study the mathematical foundations of different evolutionary models thatanalyze the evolution of a society composed of two populations with antagonistic interests.Populations are involved in a conflict whose solution depends on the action chosen by eachindividual. None of them are able to impose a solution on the other population. Two individuals,one from each population, are randomly chosen to play a game. In a strategic way,each individual of each population, must choose one of two feasible strategies. The solutionobtained for each population will be the result of the aggregated action of the individuals.Fil: Accinelli Gamba, Elvio. Universidad Autónoma de San Luis Potosí; MéxicoFil: Martins, Felipe. Universidad de Porto; PortugalFil: Quintas, Luis Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; Argentin

Computational implementation of indices of power

In this paper we present algorithms and computational implementation of the Shapley Value and Banzhaf– Coleman Index of Power. Both indices describe the real power of the coalitions involved in strategic interactions. The system allows the study of complex Electoral Applications. The data input can be done in two different ways: by considering all the possible coalitions, or only the basic coalitions (political parties, sectorial groups, etc.). The system also allows to introduce restrictions (incompatibilities) among some coalitions. We present some applications for computing the Electoral Power in the election of authorities in Universidad Nacional de San Luis. We describe the client–server design and the implementation of these tools, using the languages C and Tcl/Tk. The server program is written in C and requires Linux. The Client Program is written in Tcl/Tk with namespace mechanism and it supports Linux and Windows.Área: Informática Teórica - Inteligencia Artificial - Lenguajes - CompiladoresRed de Universidades con Carreras en Informática (RedUNCI

A functional approach for in line analytical processing

This paper describes an approach to On Line Analytical Processing (OLAP), expresed in the declarative programming paradigm. We define a collection of functions that capture some of the functionality currently provided by multidimensional database product. This is done by defining operations which allow for classifying and reducing relations (tables). Suitably combined, these operations will make possible to carry out the multidimensional analysis of a relational database, and make possible the declarative specification and optimization of multidimensional database queries. The library works over an abstract model of the relational database calculus as defined by Maier, written in the style of model-oriented formal specification in the functional language HaskellEste paper describe una aproximación al Procesamiento Analítico On Line (OLAP), desarrollado en el paradigma de la programación declarativa. Definimos un conjunto de funciones que capturan algunas de las funcionalidades actualmente provistas por las bases de datos multidimensionales existentes. Esto es realizado definiendo operaciones que permiten clasificar y reducir relaciones (tablas). Dichas operaciones, convenientemente combinadas, permitirían llevar a cabo el análisis multidimensional de una base de datos relacional, junto con la especificación declarativa y optimización de las correspondientes consultas multidimensionales sobre dicha base. La biblioteca provista trabaja sobre un modelo abstracto del cálculo de base de datos relacionales tal como ha sido definido por Maier, escrito en un estilo de especificación formal orientada al modelo en el lenguaje funcional HaskellIII Workshop de Ingeniería de Software y Bases de Datos (WISBD)Red de Universidades con Carreras en Informática (RedUNCI

A dynamic model for rumors spread with communication costs

In this article we start by reviewing some mathematical models for the spreadof rumors. We mention some studies carried out using graphs, stochastic andprobabilistic models and also some epidemic like and evolutionary models.We analyze a repeated game with the replicator dynamics for the spread ofa rumor in a society conformed by an informed population about a rumorthat communicates the rumor to another population. The rumor can becommunicated in its original form or with the opposite content. We comparethe results obtained when only social costs are involved with the case whenalso communication costs are present.Fil: Accinelli , Elvio. Universidad Autónoma de San Luis Potosí; MéxicoFil: Quintas, Luis Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: Muñiz, Humberto. Universidad Autónoma de San Luis Potosí; MéxicoFil: Rosenstock, Nicole. Universidad Autónoma de San Luis Potosí; Méxic

Reglas proporcionales en problemas de árboles de mínimo costo

En este trabajo se presenta una nueva familia de reglas de distribución para problemas de árboles  de mínimo costo. Se utilizan criterios de proporcionalidad para estas reglas y a través de un ejemplo clásico se observa un mejor comportamiento que las reglas de Bird, Kar y Dutta-Kar. Se prueban algunas propiedades que cumplen estas reglas proporcionales y se concluye que comparativamente, desde el punto de vista de las propiedades que cumplen, se encuentran bien posicionadas.Fil: Cesco, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: Pepa Risma, Eliana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: Quintas, Luis Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; Argentin