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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Análise dos estoques em processo de um sistema de produção de cabinas de caminhões com o uso da simulação de eventos discretos / The cabins storage system analysis from a commercial vehicle production system by the use of discrete event simulation

João Gilberto Zalla Filho 25 January 2006 (has links)
Essa dissertação tem como objetivo utilizar a simulação de eventos discretos na análise dos estoques seletivos em processo de cabinas, em uma montadora de veículos comerciais de grande porte instalada no Brasil. A análise e a redução desses estoques seletivos são desejadas, pois o armazenamento de cabinas de caminhões, além de representar um alto custo para a produção, é de difícil controle e de alto risco. O desenvolvimento deste trabalho contribuirá para o conhecimento das dificuldades e benefícios da aplicação da simulação de sistemas discretos em sistemas produtivos de alta complexidade, como são os sistemas de manufatura da indústria automobilística. A análise desse sistema é de significativa dificuldade, devido ao tamanho dos produtos, ao mix de produção, à variabilidade do fluxo das etapas de produção e às diversas variáveis que influem no sistema simultaneamente. A técnica de simulação de eventos discretos foi escolhida por ser a mais indicada para analisar todo o sistema e auxiliar na tomada de decisão. Todo o estudo do sistema, modelagem, verificação, validação, simulação e resultados foram feitos de acordo com procedimentos já sedimentados para o uso da simulação de eventos discretos, de acordo com a bibliografia apresentada. Os resultados mostram a eficiência do método utilizado e propõem um cenário otimizado para o sistema estudado. O estudo foi realizado com a utilização do software de simulação de eventos discretos, Arena® 5.0. / This work has the main objective to use the discrete event simulation to analyze the in process cabins selective banks of a commercial vehicle assembler. The analysis and reduction of the selective banks are useful because the storage of cabins represents some production risks, is hard to control and implies in high costs. The developing of this work will contribute to the knowledge of the difficulties and benefits of the use of discrete event simulation applied to high complexity production systems like the automotive industry. The size of the products, the production mix, the throughput variability and the other simultaneous variables turn the storage analysis to a hard level. In this way, the discrete event simulation is the most indicated technique to help the analysis and the decision making. The whole study of the system, the modeling, the validation, the simulation runs and the results were done according to known procedures of using the discrete event simulation, which are mentioned in the references. The presented results show the efficiency of the utilized method and proposed optimized scenery of the studied system. The simulation software Arena 5.0 was used in this study.
92

How a Discrete event simulation model can relieve congestion at a RORO terminal gate system : Case study: RORO port terminal in the Port of Karlshamn.

vadlamudi, jithin chand January 2016 (has links)
Context. Due to increase in demand for RORO shipping services,the RORO terminal gate system need to handle more number of vehicles for every RORO vessel departure. Therefore, various congestion problems can occur; so, to address all possible congestion related problemsat RORO terminal, terminal gate systems are implemented with advanced technologies and updated to full or partial functioning automated gate systems. Objectives. In this research study considering the future increase in demand for wheeled cargo shipping, we attempt to propose a solution for reducing congestion and investigating optimal positions for each automated gate system service at RORO port terminal. Methods. In this Master thesis, as part of qualitative study we conduct a literature review and case study to know about the existing related work on this research problem and know about the real world system operation and behaviour of a RORO terminal gate system.Later, applying the adequate knowledge acquired from above mentioned qualitative studies, we perform a discrete event simulation experiment using Anylogic® professional 7.02 simulation software to address defined research objectives. Results. Considering the peak and low periods of present and future estimated demand volumes as different scenarios,various simulation experiment results are generated for different key performance indicators. The result values of these key performance indicators address various research objectives. Conclusions. This research study finally concludes that, the average queue length values at each automated gate system service implicates optimal position for each service and directly address the congestion problem. We also conclude that in every estimated increase in vehicles attending the RORO terminal, assigning optimal arrival time windows for respective vehicle types minimizes the congestion problem at automated gate system.
93

Simulation of AssistiveSystems for Elderly People

Garcia Perez, David January 2014 (has links)
Aging population is becoming a problem in a lot of countries, being Swedenone of them, and that is leading society to a lack of the necessary peopleto take care of all the elderly people. The CareIP device, an alarm systemfor the elderly people, with which they are able to ask for assistive help incase they need it, has been used all over Sweden for a while now. In thisthesis, a simulation model has been built in order to study how this caregiving system works in the specic case of Vaxjo. This model can be usedto simulate real situations and prevent certain problems as it could be thelack or excess of resources, long waiting times or unexpected increase on thenumber of alarms, which could lead to critical situations on a emergencyhealthcare system.
94

A NEW STUDY OF UNBALANCED PRODUCTION LINE WITH OPTIMIZATION / EN NY INSIKT ANGÅENDE OBALANSERAD PRODUKTIONSLINJE MED HJÄLP AV OPTIMERING.

Xia, Johnny January 2018 (has links)
This project is a continuous research of a topic well-known in the literature, namely, the performance study of unbalanced unpaced production system. In the literature, there were many studies that investigated the statistical outputs of an unbalanced production line using simulation. This project focuses on researching the outputs like average buffer level and idle time that are rarely studied in previous research by using optimization tools from discrete event simulation software FACTS.The models used in the article (Shaaban & McNamara, 2009) have been used as a guideline during the development of the simulation models for this project. Two simulation models were created, each using different discrete event simulation software, namely FACTS analyzer and Plant simulation. Those simulation models fulfills its role in verification & validation stage, with their statistical outputs compared to each other and with Shaaban and McNamara’s results. After verification & validation comes optimization of those simulation models, by using optimization tools from FACTS.The research area expanded during the optimization phase. Originally Shaaban et.al analyzed unbalanced production line with one fixed value of coefficient of variation. In order to expand the view on the properties of an unbalanced production line, three more coefficient variation were added with total of four in this project. As a result, 12 optimization results were created at the end of this project. Each optimization has 30 000 iterations to ensure its convergence.The first step of analysis is done by locating all Pareto-optimal solutions with optimization tools in FACTS. The raw data of all solutions are later transferred and converted into EXCEL files. Using scatter graph and putting all outputs against each other in EXCEL, it creates visual graph that can be used to analyze and to investigate interesting behavior in an unbalanced production line.The analysis on the optimization results showed several interesting behaviors from production line with different settings. One being that if a production line possess worse coefficient of variation than its competition. By raising the inter-stage buffer level of the production line with inferior coefficient of variation, it can achieve the same level, if not greater outputs than its competitor who possess better coefficient of variation. The other interesting behavior are optimization results with highest outputs in regard of either idle time or average buffer level, with deep analyzation using optimization tools from FACTS. Certain operation time pattern and inter-stage buffer pattern could be observed from those results.
95

Toward Distributed At-scale Hybrid Network Test with Emulation and Simulation Symbiosis

Rong, Rong 28 September 2016 (has links)
In the past decade or so, significant advances were made in the field of Future Internet Architecture (FIA) design. Undoubtedly, the size of Future Internet will increase tremendously, and so will the complexity of its users’ behaviors. This advancement means most of future Internet applications and services can only achieve and demonstrate full potential on a large-scale basis. The development of network testbeds that can validate key design decisions and expose operational issues at scale is essential to FIA research. In conjunction with the development and advancement of FIA, cyber-infrastructure testbeds have also achieved remarkable progress. For meaningful network studies, it is indispensable to utilize cyber-infrastructure testbeds appropriately in order to obtain accurate experiment results. That said, existing current network experimentation is intrinsically deficient. The existing testbeds do not offer scalability, flexibility, and realism at the same time. This dissertation aims to construct a hybrid system of conducting at-scale network studies and experiments by exploiting the distributed computing ability of current testbeds. First, this work presents a synchronization of parallel discrete event simulation that offers the simulation with transparent scalability and performance on various high-end computing platforms. The parallel simulator that we implement is configured so that it can self-adapt for the performance while running on supercomputers with disparate architectures. The simulator could be used to handle models of different sizes, varying modeling details, and different complexity levels. Second, this works addresses the issue of researching network design and implementation realistically at scale, through the use of distributed cyber-infrastructure testbeds. An existing symbiotic approach is applied to integrate emulation with simulation so that they can overcome the limitations of physical setup. The symbiotic method is used to improve the capabilities of a specific emulator, Mininet. In this case, Mininet can be used to run applications directly on the virtual machines and software switches, with network connectivity represented by detailed simulation at scale. We also propose a method for using the symbiotic approach to coordinate separate Mininet instances, each representing a different set of the overlapping network flows. This approach provides a significant improvement to the scalability of the network experiments.
96

Using structured analysis and design technique (SADT) for simulation conceptual modelling

Ahmed, Fahim January 2016 (has links)
Conceptual Modelling (CM) has received little attention in the area of Modelling and Simulation (M&S) and more specifically in Discrete Event Simulation (DES). It is widely agreed that CM is least understood despite its importance. This is however, not the case in other fields of science and engineering (especially, computer science, systems engineering and software engineering). In Computer Science (CS) alone, CM has been extensively used for requirements specification and some well-established methods are in practice. The aim of the thesis is to propose a CM framework based on the principles of software engineering and CS. The development of the framework is adapted from a well-known software engineering method called Structured Analysis and Design Technique (SADT), hence it is called SADT CM. It is argued that by adapting approaches from CS, similar benefits can be achieved in terms of formality, understanding, communication and quality. A comprehensive cross-disciplinary review of CM in CS and M&S is undertaken, which highlights the dearth of standards within M&S CM when compared to CS. Three important sub-fields of CS are considered for this purpose namely, information systems, databases and software engineering. The review identifies two potential methods that could be adopted for developing a M&S CM framework. The first method called PREView was found unsuitable for M&S CM in DES domain. Hence, the thesis concentrates on developing the framework based on SADT. The SADT CM framework is evaluated on three-in depth test cases that investigate the feasibility of the approach. The study also contributes to the literature by conducting a usability test of the CM framework in an experimental setting. A comprehensive user-guide has also been developed as part of the research for users to follow the framework.
97

Modelisation et aide a la decision pour l'introduction de technologies communicantes en milieu hospitalier. / Modeling and decision-support for the introduction of auto-id technologies in hospitals.

Housseman, Sylvain 15 April 2011 (has links)
Cette thèse traite de l'évaluation des apports de l'introduction de nouvelles technologies de l'information et de la communication (NTIC), les technologies d'IDentification par Radio-Fréquences (RFID), dans le milieu de la Santé.Un premier objectif a naturellement consisté en la description des particularités de la production de soins et de l'organisation hospitalière, ainsi que des problématiques associées à la mise en place de systèmes RFID dans un contexte plus général et une présentation des outils permettant de répondre à ces problématiques.Suivent deux cas d'application issus du projet MISTRALS (Mutualisation Informatique des Systèmes Technologiques pour le Recherche phArmaceutique et La Santé) que sont les tumorothèques et la production de chimiothérapies.La partie "générique" des impacts des technologies mènent à la proposition d'une approche descriptive adaptée au problème. Les apports des technologies permettent d'inventorier les boîtes de cryotubes stockées à très basse température rapidement et précisément. Cette observation nous a poussés à définir et étudier des possibilités de la mise en place de l'activité de concaténation de ces boîtes. Cette activité et une approche d'optimisation la concernant sont intégrées à un outil de simulation par évènements discrets.L'intérêt des objets communicants est également pluriel dans la production des chimiothérapies. Outre les apports logistiques, les RFID permettent d'acquérir des données fiables pour paramétrer les profils et la performance des ressources humaines. Nous déterminons une approche de génération d'ordonnancements intégrant la gestion des compétences et l'intégrons à une simulation à évènements discrets. / This thesis aims at evaluating the impacts of Radio-Frequency Identification (RFID) within a healthcare context.The first parts of this dissertation describe the particularities of health-production systems, the problematic of introducing RFID technologies within a general context, and present the tools that can be used to answer questions related to implementing new information and communication technologies within hospitals.Two use cases are developed. They concern tumour-banks (and more generally biobanks) and chemotherapies production systems.The generic impacts of RFID technologies led us proposing an adapted descriptive approach.Technologies allow fast and acute inventories, even concerning cryotubes containing biological samples that are stored at very low temperatures. This observation led us to define and study the possibilities for re-organizing these particular stocks. This activity and a specific optimization approach are included in a discrete-event simulation tool.Several improvements can also be raised through the use of auto-communicating devices within a chemotherapy production system. We focus on using real-time data to estimate the evolution of competency of the human resources concocting cytotoxics. We describe an optimization approach for scheduling the production of chemotherapies considering the resources performance level, and include this tool within a dedicated discrete-event simulation model.
98

Förbättring av produktionsmiljö med hjälp av automation : Med Discrete Event Simulation som verktyg

Lundstedt, Moa, Hronek, Sofie January 2017 (has links)
In order to meet the expectations of today’s market and compete in the global world we live in, many companies are facing changes. A low cost production and high quality is not enough to be competitive. Companies must also satisfy the external customers’ claims, which to a great extent imply demands on an increased productivity. It is not enough to look to the external customers. The people working within the production system are the internal customers and the production system must be designed to suit their needs. Increased productivity can be stressful for operators, especially in the automotive industry, where heavy and frequent lifting is part of the daily work. The increased competition can thus in the long run lead to consequences for operator health as a result of heavy, and frequent, lifting. Due to this, more companies are looking over the possibilities to automate parts of their production process. The purpose of this thesis is to explore, using simulation tools, how automation of heavy lifting can affect productivity and work environment in processing or manufacturing processes. The research questions that will be answered are: o In what way does automation affect productivity in processing processes? o How can simulation tools act as an aid in designing automation? o What impact does automation have on the operator’s ergonomic work environment? To answer these questions, a literature study has been conducted in three main areas: production development, automation and simulation. A case study was carried out in a processing cell within the heavy vehicle industry, which currently does not have an approved ergonomic working environment. The company wanted to implement a robot and the purpose was to investigate how ergonomics and productivity was affected. The comparison was made using a simulation created in the ExtendSim software. The purpose of the simulation was to compare the current production system with a layout where a robot was implemented in the system. From this thesis, the conclusions were drawn that automation can affect a company’s productivity in a positive way provided that the preparatory planning is carried out thoroughly. The thesis shows that a simulation tool can be helpful from a number of aspects when automation is to be designed, and not least that it can undoubtedly be positive for the operator’s ergonomic work environment to automate parts of the production that includes heavy and frequent lifting.
99

Aduana do Brasil e medidas de facilitação comercial : estudo simulado de melhorias no despacho aduaneiro de importação aérea / Brazilian customs and trade facilitation measures : simulation study of improvements on air import customs clearance

Ferreira, Yuri da Cunha, 1991- 05 April 2015 (has links)
Orientadores: Cristiano Morini, Luís Antonio de Santa-Eulalia / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas / Made available in DSpace on 2018-08-27T16:46:50Z (GMT). No. of bitstreams: 1 Ferreira_YuridaCunha_M.pdf: 2095505 bytes, checksum: e777d90d6317bbff27c249d1a35f1314 (MD5) Previous issue date: 2015 / Resumo: A Aduana (ou alfândega) é um elo da cadeia internacional de suprimentos com a função de controlar a entrada e a saída de mercadorias de um país. A transposição de mercadorias pelas fronteiras está diretamente relacionada aos processos aduaneiros. Medidas de facilitação comercial objetivam tornar o controle da Aduana mais simplificado e efetivo, tornando a cadeia de suprimentos mais fluida e segura. Iniciativas como a utilização de laudos de imagens dos escâneres de raio-X, os programas de facilitação comercial, como o Despacho Aduaneiro Expresso (Linha Azul), e metas de desempenho para servidores aduaneiros podem ser citadas como medidas de facilitação comercial. O objetivo desta pesquisa é analisar o impacto dessas medidas de facilitação comercial na Aduana brasileira, em relação aos diversos tempos que impactam o fluxo de importação. Não existem estudos nas literaturas científica e profissional que analisem quantitativamente os impactos dessas medidas de facilitação comercial no Brasil. Caracterizada pelo método de pesquisa explicativa de natureza experimental, por meio da ferramenta de simulação de eventos discretos, foi desenvolvido um Projeto de Experimentos Fatorial 2^k Completo. O objeto do estudo experimental foi aplicado no fluxo de importação aérea no Aeroporto Internacional de Viracopos, Campinas. Os dados utilizados são originários dos sistemas TECAPLUS e MANTRA e de entrevistas com experts. Durante o desenvolvimento da pesquisa, diversos especialistas da área de comércio exterior estiveram envolvidos, desde a formulação do problema à validação do modelo computacional. Os resultados obtidos nas rodadas de simulação indicam uma melhoria progressiva do sistema simulado em todos os indicadores de desempenho entre o status quo e o cenário de melhor performance. A análise de contrastes dos fatores indica que: o aumento de empresas habilitadas em programas de facilitação comercial (Linha Azul) diminui o tempo médio geral de desembaraço aduaneiro; a utilização de laudos de imagens dos escâneres de raio-X melhora o desempenho de todos os indicadores relacionados à previsibilidade e ao tempo de desembaraço das empresas habilitadas no Despacho Aduaneiro Expresso; e, metas de desempenho para auditores-fiscais da Receita Federal contribui para o aumento da previsibilidade do sistema. Os resultados obtidos indicam melhorias que podem contribuir para ganhos de competitividade para o Brasil / Abstract: Customs is an international supply chain link with the role of controlling goods entries and exits of the country. The cross border of goods is strictly related to customs process. Trade facilitation measures aim to turn Customs control more simplified and effective, turning the supply chain more fluid and secure. Initiatives as the use of X-ray screening images report, the trade facilitation programs, as Express Customs Clearance (Blue Line), and performance goals to customs workers can be indicated as trade facilitation measures. The purpose of this research is to analyse the trade facilitation measures impacts on Brazilian Customs in relation to different times which impact the import flow. There are not studies in professional and scientific literature that make a quantitative analysis about these trade facilitation measures on Brazil. Featured by explanatory research method of experimental nature, by discrete-event simulation, was performed a 2^k Complete Factorial Experimental Design. The study object was applied on air import flow in International Airport of Viracopos, Campinas. The data are from TECAPLUS and MANTRA systems and from interviews with experts. During the development of this research, plenty trade international experts were involved, since problem formulation until computational model verification. The reached results in simulation runs show a progressive improvement in simulated system in all performance indicators between status quo and the best performance scenario. The factors contrasts analysis shows: raising enterprises in trade facilitation programs (Blue Line) decreases general average time of customs clearance; using X-ray screening images report improves all performance indicators related to predictability and to customs clearance time of enterprises qualified in Express Customs Clearance; and, performance goals to Federal Revenue auditors contribute to increase system predictability. The reached results point out improvements that may provide competitiveness gains to Brazil / Mestrado / Pesquisa Operacional / Mestre em Pesquisa Operacional
100

Desenvolvimento de um modelo de simulação para apoio ao gerenciamento de projetos de desenvolvimento de medicamento genérico em uma empresa farmacêutica

Silva, Ellen Martins Lopes da 25 February 2015 (has links)
Submitted by Nadir Basilio (nadirsb@uninove.br) on 2016-06-01T14:12:26Z No. of bitstreams: 1 Ellen Martins Lopes Da Silva.pdf: 1971538 bytes, checksum: efc5874f81cd876675f899e6b489527a (MD5) / Made available in DSpace on 2016-06-01T14:12:26Z (GMT). No. of bitstreams: 1 Ellen Martins Lopes Da Silva.pdf: 1971538 bytes, checksum: efc5874f81cd876675f899e6b489527a (MD5) Previous issue date: 2015-02-25 / In the pharmaceutical industry, research and launching of brand-name or generic pharmacy is the main point in the pattern of industry competition. However, the drug development project involves many processes that interrelate, making their management difficult for the project manager. Despite the existence of methods used in project management, such as CPM, PERT and GANTT chart, these methods have limitations when the couldn't treat appropriately more complex projects, involving stochastic and dynamic interaction of a set of objects, such as people or machines, for example, aimed at a target or logical connection. Other techniques, based on Mathematical Programming, for example, are normally specific used in situations and goals, such as minimizing the end date of a project. Therefore, considering the goal of developing a model to be used with different purposes, discrete-event simulation was adopted in this work. This work presents the construction of a computational model of discrete-event simulation, aimed at the development of generic drug of a pharmaceutical industry, and aims to assist project managers as part of a set of systems to support decision-making. The results of the validation and verification of the model show that the values obtained from the simulation converge with the historical values obtained and with information from the experts. The constructed model has modules that allow estimating the impact of variables on the duration of the project, monitoring the use of system resources making it possible to estimate, from the simulation, the real capacity of the system, the possibility of accepting new projects and the need to acquire new features. / No ramo farmacêutico a pesquisa e lançamento de produtos referência ou genérico é o ponto principal no padrão de competição da indústria. Porém, o projeto de desenvolvimento de medicamentos envolve muitos processos que se inter-relacionam, tornando seu gerenciamento difícil para o gestor de projetos. Apesar da existência de métodos e técnicas muito utilizados no gerenciamento de projetos, como PERT, CPM e gráfico de GANTT, essas abordagens possuem limitações não conseguindo tratar de forma adequada projetos mais complexos, que envolvam a interação dinâmica e estocástica de um conjunto de elementos, como pessoas ou máquinas, por exemplo, visando um objetivo ou propósito lógico. Outras técnicas, baseadas em Programação Matemática, por exemplo, são geralmente utilizadas em situações e objetivos específicos, como por exemplo, minimizar a data de término de um projeto. Assim, considerando o objetivo de desenvolver um modelo para ser usado com diversos propósitos, a simulação de eventos discretos foi adotada neste trabalho. O trabalho apresenta a construção de um modelo computacional de simulação de eventos discretos, voltado para o desenvolvimento de medicamento genérico de uma empresa farmacêutica, e tem por objetivo auxiliar gestores de projeto como parte de um conjunto de sistemas de apoio à tomada de decisão. Os resultados da validação e verificação do modelo demonstram que os valores obtidos por meio da simulação convergem com os valores históricos obtidos e com informações dos especialistas. O modelo construído possui módulos que permitem estimar o impacto das variáveis na duração do projeto, monitorar a utilização dos recursos do sistema possibilitando estimar, a partir da simulação, a real capacidade de atendimento do sistema, a possibilidade de aceitação de novos projetos e eventualmente a necessidade de aquisição de novos recursos.

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