Rogério Luís Rizzi

Dynamic load balancing in PC clusters: an application to a multiphysics model

We describe the use of dynamic load balancing in a PC cluster, applied to a multiphysics model that combines the parallel solution for three-dimensional (3D) PDEs of shallow water bodies flow and the parallel solution for the three-dimensional PDEs of scalar transportation of substances. The dynamic load balancing is obtained via diffusion algorithms. The numerical mesh is partitioned using RCB algorithm, in order to minimize communication and balance the load. Parallelism is obtained through Schwarzs additive domain decomposition method (DDM), so that the subproblems are solved concurrently. SPMD is the programming model used and the message passing between processes in the PC cluster is done with MPICH library.

A Utilização do Software Wiris na Plataforma Moodle Visando o Ensino da Matemática: o Relato de um Projeto de Extensão

Este artigo apresenta alguns resultados obtidos pela realizacao de um projeto de extensao universitaria que foi realizado no municipio de Catanduvas – Parana, cujo principal objetivo era o de articular a Matematica e a Informatica visando contribuir para a melhoria das condicoes de cidadania, emprego, renda e acesso as instituicoes de ensino superior, por parte de alunos que cursavam o ensino medio. Relata a utilizacao do software Wiris Editor utilizado em um curso disponibilizado no ambiente Moodle criado para atender os alunos do projeto.

Computational Agents Applied to Dengue Fever Simulation

This paper summarizes the three main modules of a computing system whose goal is to automate specific actions aiming to provide combat and control of dengue. The module I is an information system on Dengue. Modules II and III perform simulations on dengue using computational agents.

A Multigrid-Schwarz Method for the Solution of Hydrodynamics and Heat Transfer Problems in Unstructured Meshes

This paper presents a parallel multigrid-Schwarz method for the solution of hydrodynamics and heat transfer problems. In the proposed method, the solution is obtained by a multigrid method parallelized by domain decomposition techniques, more specifically by the additive Schwarz method. The experiments performed have shown that the proposed implementation is computationally efficient, have good scalability, and good numerical quality.

Parallelization of Krylov Subspace Methods in Multiprocessor PC Clusters.

Publisher Summary This chapter describes the parallelization of two Krylov subspace methods in multiprocessor clusters. The objective of this parallelization was the efficient solution of sparse and huge linear equations systems, resulting from the discretization of a hydrodynamics and mass transport model. The objective of this work is to compare of the use of different tools, as well as the use of different approaches to the exploration of intra-node parallelism, presenting an analysis of the results obtained. In this work, the computational performance is also compared obtained with the use of two processors in dual processor nodes, and the use of a single processor in each node, using more nodes to get the same number of processors. From the obtained results an analysis of the cost/benefit ratio of the use of dual machines versus mono-processed machines in PC clusters is done. An important issue that must be considered in the decision of using dual processor nodes or mono-processed nodes is memory contention. Some tests done with two processes in dual processor nodes showed that memory contention grows with the use of memory by the application. This result suggests that, in applications that use less memory and have a good scalability, the use of multiprocessor nodes is more viable, as it presents a similar result to that obtained using mono-processed nodes, by a lower cost. Other advantage in the use of multiprocessor nodes is the possibility of exploration intra-node parallelism through the use of multithreading.