Manuel S. Lazo-Cortés

Algorithm for shortest path search in Geographic Information Systems by using reduced graphs

The use of Geographic Information Systems has increased considerably since the eighties and nineties. As one of their most demanding applications we can mention shortest paths search. Several studies about shortest path search show the feasibility of using graphs for this purpose. Dijkstra’s algorithm is one of the classic shortest path search algorithms. This algorithm is not well suited for shortest path search in large graphs. This is the reason why various modifications to Dijkstra’s algorithm have been proposed by several authors using heuristics to reduce the run time of shortest path search. One of the most used heuristic algorithms is the A* algorithm, the main goal is to reduce the run time by reducing the search space. This article proposes a modification of Dijkstra’s shortest path search algorithm in reduced graphs. It shows that the cost of the path found in this work, is equal to the cost of the path found using Dijkstra’s algorithm in the original graph. The results of finding the shortest path, applying the proposed algorithm, Dijkstra’s algorithm and A* algorithm, are compared. This comparison shows that, by applying the approach proposed, it is possible to obtain the optimal path in a similar or even in less time than when using heuristic algorithms.

RBAC Extension Model for ERP Systems in Multidomain Environments

This paper presents an extension of the Role Based Access Control (RBAC) Model for Enterprise Resource Planning (ERP) systems, developed with the perspective of been deployed in multidomain environments, to provide the possibility of planning the resources of several institutions simultaneously from a single data center. The extension of the model allows to control the access of the users to different resources (system, services, data bases, information, among others), ensuring the compartmentalization of the information. The resulting model was applied in the development of an access control system that centralizes the security of several applications, in which user can access to various entities and fulfill many roles with the possibility of interacting with multiple resources.

Modelo para la representación de redes y búsqueda de caminos óptimos en Sistemas de Información Geográfica

Resumen es: Una de las funcionalidades presente en los sistemas de informacion geografica es la busqueda de caminos optimos. En la actualidad, este tipo de funcional...