Joselito Medina Marín

MODELO QUE IDENTIFICA LA MADUREZ DE LOS PROCESOS. CASO: PEQUEÑA EMPRESA MANUFACTURERA.

The high competitiveness in existing markets and the patterns imposed by the globalization amplify the uncertainty of the immediate future of small businesses in Mexico: that is magnified because the capabilities of meeting the expectations of sector, which is dynamic and changing, are ambiguous, caused by unfamiliarity with the maturity level of their internal processes and the ability to respond to the various subsystems in the firm. The work proposes a model that analyzes and identifies the maturity level of 5 small manufacturing business that have exceeded the threshold of disappearance, which is between 4-5 years and represents 70% of them.

EVALUACIÓN ECONÓMICA Y AMBIENTAL DE DISEÑOS ESTRUCTURALES DE EDIFICACIONES MEDIANTE ANÁLISIS DE CICLO DE VIDA BASADO EN ENTRADAS Y SALIDAS

Esta investigacion examina la aplicacion del modelo IO-ACV (Analisis de Ciclo de Vida basado en Entradas y Salidas) para evaluar opciones de diseno estructural que tengan formas rectangulares, cinco niveles de altura y sean de uso habitacional. El estudio se enfoco a los materiales estructurales mas comunes en la vivienda de interes social de la zona central de Mexico: concreto, acero de refuerzo y madera de cimbra. El ACV convencional o por procesos requiere datos que en entornos como el caso de Mexico son dificiles de obtener. El IO-ACV es una alternativa para evaluar un producto desde el punto de vista ambiental ya que solo requiere datos de las transacciones que se realizan entre los sectores economicos involucrados en el ciclo de vida del producto. No obstante que dicho modelo esta disenado para un contexto industrial como el de los Estados Unidos o Europa, se puede obtener una evaluacion ambiental aproximada al ACV convencional o tambien denominada por procesos. Este articulo analiza las diferencias en las estimaciones que se pueden obtener con el modelo IO-ACV y tomando como referencia el ACV por procesos. Se presenta una propuesta para usarlos de manera complementaria en dos fases: la primera, una evaluacion amplia o general basada en el metodo EIO-LCA, el cual se basa en el modelo IO-ACV y la segunda, una evaluacion detallada basada en el ACV de los materiales y el transporte. La propuesta fue aplicada en la evaluacion de cuatro disenos estructurales en la zona central de Mexico y las variaciones en las estimaciones con el modelo IO-ACV permiten darle utilidad en el contexto de Mexico.

Solution to travelling salesman problem by clusters and a modified multi-restart iterated local search metaheuristic

This article finds feasible solutions to the travelling salesman problem, obtaining the route with the shortest distance to visit n cities just once, returning to the starting city. The problem addressed is clustering the cities, then using the NEH heuristic, which provides an initial solution that is refined using a modification of the metaheuristic Multi-Restart Iterated Local Search MRSILS; finally, clusters are joined to end the route with the minimum distance to the travelling salesman problem. The contribution of this research is the use of the metaheuristic MRSILS, that in our knowledge had not been used to solve the travelling salesman problem using clusters. The main objective of this article is to demonstrate that the proposed algorithm is more efficient than Genetic Algorithms when clusters are used. To demonstrate the above, both algorithms are compared with some cases taken from the literature, also a comparison with the best-known results is done. In addition, statistical studies are made in the same conditions to demonstrate this fact. Our method obtains better results in all the 10 cases compared.

Reversibility, Simulation and Dynamical Behaviour

A cellular automaton (CA) is reversible if it repeats its configuration in a cycle. Reversible one-dimensional CA are studied as automorphisms of the shift dynamical system, and analyses using graph-theoretical approaches and with block permutations. Reversible CA are dynamical systems which conserve their initial information. This is why they pose a particular interest in mathematics, coding and cryptography.

Petri Nets Representing the Evolution of Elementary Cellular Automata

A Petri net (PN) is a directed graph which consists of two kinds of nodes called places and transitions. Besides their graphical representation, PN possess a mathematical formalism based on the incidence matrix and the state equation. In this paper we show that PN can be used as a general tool to represent the evolution of any elementary cellular automaton (ECA). This is performed by matrix operations obtained from the state equation of the PN which represent the cellular automaton and the use of a logical operator. It is presented an algorithm to construct a PN for any ECA and we give some comparative examples between the evolution of markings of the PN and the evolution of the respective ECA.