Túlio Almeida Peixoto

Simulation model in a free and open-source software for carbon monoxide emissions analysis

This paper describes an analysis of emissions of carbon monoxide (CO) using a discrete event simulator of open source. A simulation model was built to evaluate gas emissions emitted by a fleet of trucks during transportation of raw materials in a typical supply system of sugarcane in producer mills of ethanol. The simulation model was implemented in the open source simulator and a traditional simulator. The model results presented high correlation, with no significant difference between them. It was also possible to contribute with the proposed simulator through a designed component able to account the CO emissions.

Ururau: a free and open-source discrete event simulation software

This paper has the purpose of describing the architecture and operation of Ururau, a software used to create discrete event simulation models based on the Java Simulation Library. Ururau is a free and open-source multiplatform software, which allows the user to develop models in the graphical interface or implement them directly in the source code. This characteristic allows the user to employ it as a tool for modeling and simulation of discrete event systems and also as a learning tool. Thus, an experienced modeler can add specific algorithms to simulation models or new features to the simulator. Also, with access to the source code, a beginner modeler can understand the internal structure of a discrete event simulation software. Initial results have demonstrated this new software’s ability in building small and simple models efficiently.

SIMULATION OPTIMIZATION FOR ANALYSIS OF SUSTAINABLE LOGISTICS SYSTEMS

This work analyzed different logistics structures under a sustainable perspective. It was developed a discrete event simulation model associated with optimization algorithm to evaluate the best combinations of the model. Besides, the comparison between the simulation optimization and a multicriteria method was performed. The simulation software Ururau, in which a model with optimization algorithm allowed testing different variables, was applied in order to find the best answer to the issue. Results showed that a connection of direct proportionality between variables of transport time, greenhouse gas emissions and lead time can happen. It was also checked that the solution returned by the simulation optimization was similar to the multicriteria method in most of the tests. The ones that differed were due to small mathematical precisions between the methods.

Análise do fluxo de operações em um servidor de email através de simulação a eventos discretos com o software livre Ururau

Este trabalho apresenta um modelo de simulacao a eventos discretos para analise do processamento de um servidor de email. Sao analisados o envio e o recebimento de mensagens, levando em consideracao o periodo do lead time dos mesmos. O modelo de simulacao considerou todo processamento do servidor, desde a chegada de emails ate o envio para os destinatarios. Assim, o modelo proporcionou a visualizacao dos tempos gastos em cada processo, a utilizacao dos recursos e, em especial, o principal problema enfrentado pela empresa, que e o alto lead time das mensagens no servidor. As simulacoes foram realizadas utilizando o software livre de simulacao Ururau. Os resultados mostraram que o software livre obteve resultados equivalentes aos de outro software comercial tradicionalmente utilizado, sem diferenca estatistica significativa entre eles.

Analysis of carbon monoxide emissions in a open source discrete-event simulator

This paper describes an analysis of emissions of carbon monoxide (CO) using a discrete event simulator of open source. It was built a simulation model to evaluate gas emissions emitted by a fleet of trucks during transportation of raw materials in a typical supply system of sugarcane in producer mills of ethanol. The simulation model was implemented in the open source simulator and in a traditional simulator. The model results presented high correlation, with no significant difference between them. It was also possible to contribute with the proposed simulator through a designed specific component able to account the CO emissions.

SIMULATION OPTIMIZATION IN DOSING PROCESS CONTROL SYSTEM IN REAL TIME IN A FREE AND OPEN-SOURCE SOFTWARE

The purpose of this work is to implement an on-line control system able to adjust the production in real time applying a simulation model with algorithmic optimization and data transfer for a programmable logic controller. The Solver tool of the Excel software was integrated into a simulation software used to find the optimal dosing of input aggregates in a Hot Mix Asphalt process. Tests were carried out in different scenarios; the results demonstrated that the proposed control was effective, leading to a possible improvement in the quality of the product, enabling it to be kept within the specifications desired for most of the time. Besides, the proposed solution appeared to be simple and accessible for small companies as it applies the Excel software and a free and open-source discrete event simulation software.

Communication Mechanism of the Discrete Event Simulation and the Mechanical Project Softwares for Manufacturing Systems

Abstract This paper presents an integration mechanism for online communication between a discrete event simulation (DES) software and a system dynamics (SD) software. The integration between them allowed executing a hybrid and broader simulation, in which the complexity of the systems and their multi-faceted relationships may demand the combination of different simulation methods and the synergies between the techniques. The Ururau free and open-source software (FOSS) was applied to implement the DES model. In order to build the dynamic model, we used the software for mechanical design called CAD 3D Software Inventor®. Besides, we also employed the DES model in the test step of a control system in real time. The results of that mechanism implementation enabled the evaluation of different aspects of a typical manufacturing system. Furthermore, the integration between the control system and the DES model allowed validating the logic of the programmable logic controller (PLC).

Comissionamento de uma linha de produção no software de simulação a eventos discretos Ururau

Objetivo deste trabalho foi demonstrar o funcionamento de um modelo de simulacao a eventos discretos, construido com o software Ururau integrado a um controlador logico programavel para ser empregado em comissionamento de sistemas de controle. O trabalho apresenta ainda diversos testes realizados para ilustrar diferentes possibilidades de comissionamento com o software . Os resultados mostraram a viabilidade do Uruaru em ser empregado com este proposito e, tambem, o mecanismo interno responsavel pelo funcionamento da comunicacao de um modelo de simulacao e um controlador digital.

DECISION WITH ARTIFICIAL NEURAL NETWORKS IN DISCRETE EVENT SIMULATION MODELS ON A TRAFFIC SYSTEM

This work aims to demonstrate the use of a mechanism to be applied in the development of the discrete-event simulation models that perform decision operations through the implementation of an artificial neural network. Actions that involve complex operations performed by a human agent in a process, for example, are often modeled in simplified form with the usual mechanisms of simulation software. Therefore, it was chosen a traffic system controlled by a traffic officer with a flow of vehicles and pedestrians to demonstrate the proposed solution. From a module built in simulation software itself, it was possible to connect the algorithm for intelligent decision to the simulation model. The results showed that the model elaborated responded as expected when it was submitted to actions, which required different decisions to maintain the operation of the system with changes in the flow of people and vehicles.

SIMULAÇÃO A EVENTOS DISCRETOS COM MÓDULO DE DECISÃO UTILIZANDO REDES NEURAIS ARTIFICIAIS - APLICAÇÃO COM O SOFTWARE URURAU

O estudo propoe apresentar um exemplo de aplicacao do sofware de simulacao a eventos discretos livre de custos e de codigo aberto Ururau, com foco na funcionalidade de decisao atraves de Redes Neurais Artificiais (RNA). Foi elaborado um modelo para demonstrar e validar esta funcao de decisao integrada com o software. Este modelo ilustra um cenario em que uma empresa manufatureira deveria escolher entre dois fornecedores com base nas emissoes de CO2 e custos gerados por cada um deles. Apos os testes, uma analise foi feita do relatorio final da simulacao referente a cada fornecedor verificando os tempo e numero nas filas dos processos, as taxas de utilizacao dos recursos, as emissoes geradas, os custos e a media de aprovacoes e reprovacoes de cada fornecedor. Por fim, concluiu-se que o Ururau e a funcao de decisao com RNA apresentaram uma boa integracao. Palavras-chave: Simulacao a eventos discretos; Free open source; Ururau; Decisao; Redes Neurais Artificiais; Sustentabilidade.