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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.
1

Procedimento para projeto de arranjo físico modular em manufatura através de algoritmo genético de agrupamento / Procedure to the design of modular facility layouts through clustering genetic algorithm

Argoud, Ana Rita Tiradentes Terra 16 March 2007 (has links)
O objetivo desta tese foi desenvolver um procedimento para projeto de arranjo físico modular. O procedimento usa um algoritmo genético de agrupamento para gerar módulos de arranjo físico em manufatura. Um módulo é um grupo de máquinas com um fluxo característico. O algoritmo genético de agrupamento (AGA) permite ao usuário especificar a priori o número desejado de módulos (problema de K-agrupamentos), e também trabalhar de forma que o número e formação dos módulos seja uma otimização do problema (problema de agrupamento automático). Uma característica importante do AGA é sua flexibilidade, pois fornece possibilidade ao usuário de dirigir seu raciocínio através da escolha de diferentes codificações do cromossomo, de funções de aptidão para avaliar a qualidade da solução, de medidas de similaridade para comparação de seqüências de operações e de métodos de geração da nova população. Para tal foram desenvolvidos três operadores de cruzamento e quatro operadores de mutação. Os experimentos permitiram avaliar o comportamento do AGA com diferentes operadores e configurações de parâmetros, através do número de vezes em que a melhor solução foi encontrada. Os módulos de arranjo físico gerados pelo AGA e o arranjo físico final da fábrica foram comparados aqueles da principal referência encontrada na bibliografia em projeto de arranjo físico modular. No arranjo físico final da fábrica, elaborado a partir das soluções do AGA, houve importante redução da distância total percorrida pelo conjunto de peças, demonstrando a eficácia do algoritmo genético de agrupamento. Dessa forma, os resultados apontaram o algoritmo genético de agrupamento como uma alternativa à geração de módulos de arranjo físico em projeto de arranjo físico modular. / The objective of this thesis was the development of a procedure to the design of modular facility layouts. The procedure uses a clustering genetic algorithm to generate layout modules. A module is a group of machines with a specific patterned flow. The clustering genetic algorithm (CGA) allows the specification of the desired number of modules (K-grouping problem) and also the optimization of the number of modules (automatic clustering problem). The genetic algorithm is very flexible and the user can guide his reasoning. It supplies different options of chromosome encoding, generation of the initial population, fitness function to evaluate the solution quality, different similarity measures for comparison of operation sequences and methods for generation of the new population. Three crossover operators and four mutation operators have been developed. The experiments have allowed evaluating the behavior of the CGA with different operators and parameters configurations, through the number of times in which the best solution was found. The layout modules generated by the CGA and the block layout were compared with the main reference which was found in literature in the design of modular facility layouts. In the block layout elaborated from the solutions of the CGA there was an important reduction of the total distance traveled by the set of parts, demonstrating the effectiveness of the clustering genetic algorithm. The results indicated that the clustering genetic algorithm is an alternative for generation of layout modules in the design of modular facility layouts.
2

Procedimento para projeto de arranjo físico modular em manufatura através de algoritmo genético de agrupamento / Procedure to the design of modular facility layouts through clustering genetic algorithm

Ana Rita Tiradentes Terra Argoud 16 March 2007 (has links)
O objetivo desta tese foi desenvolver um procedimento para projeto de arranjo físico modular. O procedimento usa um algoritmo genético de agrupamento para gerar módulos de arranjo físico em manufatura. Um módulo é um grupo de máquinas com um fluxo característico. O algoritmo genético de agrupamento (AGA) permite ao usuário especificar a priori o número desejado de módulos (problema de K-agrupamentos), e também trabalhar de forma que o número e formação dos módulos seja uma otimização do problema (problema de agrupamento automático). Uma característica importante do AGA é sua flexibilidade, pois fornece possibilidade ao usuário de dirigir seu raciocínio através da escolha de diferentes codificações do cromossomo, de funções de aptidão para avaliar a qualidade da solução, de medidas de similaridade para comparação de seqüências de operações e de métodos de geração da nova população. Para tal foram desenvolvidos três operadores de cruzamento e quatro operadores de mutação. Os experimentos permitiram avaliar o comportamento do AGA com diferentes operadores e configurações de parâmetros, através do número de vezes em que a melhor solução foi encontrada. Os módulos de arranjo físico gerados pelo AGA e o arranjo físico final da fábrica foram comparados aqueles da principal referência encontrada na bibliografia em projeto de arranjo físico modular. No arranjo físico final da fábrica, elaborado a partir das soluções do AGA, houve importante redução da distância total percorrida pelo conjunto de peças, demonstrando a eficácia do algoritmo genético de agrupamento. Dessa forma, os resultados apontaram o algoritmo genético de agrupamento como uma alternativa à geração de módulos de arranjo físico em projeto de arranjo físico modular. / The objective of this thesis was the development of a procedure to the design of modular facility layouts. The procedure uses a clustering genetic algorithm to generate layout modules. A module is a group of machines with a specific patterned flow. The clustering genetic algorithm (CGA) allows the specification of the desired number of modules (K-grouping problem) and also the optimization of the number of modules (automatic clustering problem). The genetic algorithm is very flexible and the user can guide his reasoning. It supplies different options of chromosome encoding, generation of the initial population, fitness function to evaluate the solution quality, different similarity measures for comparison of operation sequences and methods for generation of the new population. Three crossover operators and four mutation operators have been developed. The experiments have allowed evaluating the behavior of the CGA with different operators and parameters configurations, through the number of times in which the best solution was found. The layout modules generated by the CGA and the block layout were compared with the main reference which was found in literature in the design of modular facility layouts. In the block layout elaborated from the solutions of the CGA there was an important reduction of the total distance traveled by the set of parts, demonstrating the effectiveness of the clustering genetic algorithm. The results indicated that the clustering genetic algorithm is an alternative for generation of layout modules in the design of modular facility layouts.
3

Layout Design of A Third Party-Logistics Centre: A Case Study

Eren, Nurdan, Sat, Yusuf Hasim January 2010 (has links)
<p>The purpose of this thesis is to develop an integrated model which involves creative and analytical features for designing a cost effective logistics centre layout on operational level, with respect to time and space utilization. Engineering methods, creative skills, simulation and multi-criteria decision making methods were integreted in the  developed model. The model has been implemented and validated in Oskarshamn Intralog, which is a sister company of Scania. After applying the model in the case company, three different layout concepts were generated based on engineering and simulation techniques. These concepts were evaluated from utilization of space, time and flexibility aspects. Furthermore, multi criteria decision making method was used to select the most cost effective layout concept among these concepts. Different aspects helped to see various effects of warehouse operations on layout design. Simulation was used as a powerful tool to test cycle time within designed concepts. Clearly it was concluded that a combination of two concepts led to reach the expected results as an optimum point among space, time utilization and flexibility which fullfilled the answer to both academical and practical problem</p> / <p><strong> </strong></p><p>Syftet med den här uppsatsen är att utveckla en integrerad modell som inbegriper kreativa och analytiska egenskaper. Modellen ska användas till att designa en kostnadseffektiv planering av anläggningen för ett logistikcentrum på en operationell nivå, med avseende på tid- och lagerplatsutnyttjande. Tekniska metoder, kreativitet, simulering, samt “multi-criteria decision making” är integrerade i modellen. Validering och implementering av modellen skedde på Oskarshamn Intralog, ett systerföretag till Scania. Efter tillämpning av modellen på fallföretaget, genererades tre olika koncept för planering av anläggningen. Koncepten utvärderades utifrån utnyttjande av plats, tid, samt flexibilitet. Dessutom har metoden “multi-criteria decision making” använts för att selektera det mest kostnadseffektiva av de tre koncepten. Olika aspekter på tid- och lagerplatsutnyttjande, samt flexibilitet bidrog till att se olika effekter på lagerhantering. Simuleringar genomfördes för att testa cykeltiden i de utvecklade koncepten. Slutsatsen är att en kombination av två koncept ledde till det förväntade resultatet; en optimal punkt för tid- och lagerplatsutnyttjande, samt flexibilitet, vilket uppfyller svar till de akademiska och praktiska problemen</p>
4

Layout Design of A Third Party-Logistics Centre: A Case Study

Eren, Nurdan, Sat, Yusuf Hasim January 2010 (has links)
The purpose of this thesis is to develop an integrated model which involves creative and analytical features for designing a cost effective logistics centre layout on operational level, with respect to time and space utilization. Engineering methods, creative skills, simulation and multi-criteria decision making methods were integreted in the  developed model. The model has been implemented and validated in Oskarshamn Intralog, which is a sister company of Scania. After applying the model in the case company, three different layout concepts were generated based on engineering and simulation techniques. These concepts were evaluated from utilization of space, time and flexibility aspects. Furthermore, multi criteria decision making method was used to select the most cost effective layout concept among these concepts. Different aspects helped to see various effects of warehouse operations on layout design. Simulation was used as a powerful tool to test cycle time within designed concepts. Clearly it was concluded that a combination of two concepts led to reach the expected results as an optimum point among space, time utilization and flexibility which fullfilled the answer to both academical and practical problem / Syftet med den här uppsatsen är att utveckla en integrerad modell som inbegriper kreativa och analytiska egenskaper. Modellen ska användas till att designa en kostnadseffektiv planering av anläggningen för ett logistikcentrum på en operationell nivå, med avseende på tid- och lagerplatsutnyttjande. Tekniska metoder, kreativitet, simulering, samt “multi-criteria decision making” är integrerade i modellen. Validering och implementering av modellen skedde på Oskarshamn Intralog, ett systerföretag till Scania. Efter tillämpning av modellen på fallföretaget, genererades tre olika koncept för planering av anläggningen. Koncepten utvärderades utifrån utnyttjande av plats, tid, samt flexibilitet. Dessutom har metoden “multi-criteria decision making” använts för att selektera det mest kostnadseffektiva av de tre koncepten. Olika aspekter på tid- och lagerplatsutnyttjande, samt flexibilitet bidrog till att se olika effekter på lagerhantering. Simuleringar genomfördes för att testa cykeltiden i de utvecklade koncepten. Slutsatsen är att en kombination av två koncept ledde till det förväntade resultatet; en optimal punkt för tid- och lagerplatsutnyttjande, samt flexibilitet, vilket uppfyller svar till de akademiska och praktiska problemen
5

Simulation as an Enabler for ProductionSystem Development within the Indoor Vertical Farming Industry

Abbas, Anwar, Faruk Acar, Ömer January 2023 (has links)
With the increase in food consumption, new ideas, and technologies began to be developed. Inaddition, the developments generated by Industry 4.0 technologies have started to be applied tothe entire manufacturing sector and the indoor farming industry, which is currently trending.Many studies and articles have been prepared on this subject, and the main goal of each study isto produce quality products and to ensure continuity in production to cover the nonendingincrease in demand. This paper discusses how simulation technology, which is one of the industry 4.0 technologies,can be used in the production system development of the indoor farming industry. According tomany researchers, the biggest obstacle for the vertical farming industry is start-up cost, andsimulation technologies can be the solution for this since it allows future production systems tobe analyzed without any investment. To have a clear vision of how these technologies can beadapted in the indoor farming industry, this paper will find the answers to these questions, RQ1:How can simulation facilitate production system development and Industry 4.0 projects withinthe indoor farming industry? RQ2: What are the benefits and challenges when using simulationas a tool for production system development within the indoor farming industry? To reach thegoal of this paper, the case study method was used, and an indoor farming company was selectedto get more realistic data about the vertical farming system. BlueRedGold AB is a start-upcompany in the indoor farming industry, and it has a huge growth potential since they aim totransform its current production lines to be fully automated. Many articles and studies were usedto approach the solution of the research questions from a more technical and academic point ofview, and the analysis of these articles was carried out with the structured literature review method. After conducting this research, answers have been obtained for the research questions. Theauthors' solution to the layout issue, one of the case company's main challenges as indicated inthis study, was developed after extensive simulation model testing. As highlighted in this paper,it has been stated by many researchers, there are several simulation approaches to follow.However, the authors have developed a simulation modeling approach to be followed in theindoor vertical farming industry to overcome the complexity of these systems as well as thesimulation program complexity. In addition, several challenges and benefits have beenhighlighted in this paper such as the lack of ready models of the equipment used in indoorfarming which requires a knowledge of a programing language to overcome. Finally, despitechallenges, simulation technology can provide an applicable solution for production systemproblems of vertical farming companies/organizations to obtain continuous improvementphilosophy which is the main principle of Lean thinking. The generated simulation model in thisthesis project was successfully implemented, demonstrating how this technology might be aneffective solution for complex production systems as in the indoor farming sector.

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