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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.
171

Optimisation multicritère pour une gestion globale des ressources : application au cycle du cuivre en France / Multicriteria optimization for a global resource management : application to French copper cycle

Bonnin, Marie 11 December 2013 (has links)
L'amélioration de la gestion des ressources naturelles est nécessaire pour répondre aux nombreux enjeux liés à leur exploitation. Ce travail propose une méthodologie d'optimisation de leur gestion, appliquée au cas du cuivre en France. Quatre critères permettant de juger les stratégies de gestion ont été retenus : le coût, les impacts environnementaux, la consommation énergétique et les pertes de ressources. La première étape de cette méthodologie est l'analyse de la situation actuelle, grâce à une modélisation du cycle français du cuivre de 2000 à 2009. Cet examen a montré que la France importe la quasi-totalité de ses besoins sous forme de cuivre raffiné, et a une industrie de recyclage peu développée. Suite à ces premiers résultats, la problématique du traitement des déchets de cuivre, et notamment de leur recyclage, a été étudiée. Une stratégie de modélisation des flux recyclés, basée sur la construction de flowsheets, a été développée. La formulation mathématique générale du problème a ensuite été définie : il s'agit d'un problème mixte, non-linéaire et a priori multiobjectif, qui a une contrainte égalité forte (la conservation de la masse). Une étude des méthodes d'optimisation a conduit à choisir un algorithme génétique (AG). Une alternative a également été envisagée pour résoudre le problème multiobjectif par programmation linéaire en le linéarisant "sous contrainte". Ce travail a mis en évidence la nécessité de développer une filière de recyclage efficace des déchets électriques et électroniques en France. Il a de plus montré que le cuivre contenu dans les déchets ne permet pas de couvrir la demande et qu'il est nécessaire d'importer du cuivre, de préférence sous forme de débris. / Improving the natural resources management is necessary to address the many issues related to their exploitation. This work proposes an optimization methodology for their management, applied to the case of copper in France. Four criteria are identified to assess management strategies: cost, environmental impacts, energy consumption and resource losses. The first step of this methodology is the analysis of the current situation, by modelling the French copper cycle from 2000 to 2009. This analysis showed that France imports almost all of its needs as refined copper, and has an underdeveloped recycling industry. Following these initial results, the problematic of copper wastes, including recycling, has been investigated. A recycled flow modelling strategy has been developed, based on the construction of flowsheets. The general mathematical formulation of the problem is then defined. It is a non-linear, mixed and a priori multiobjective problem, with a strong equality constraint (mass conservation). A review of optimization methods has led to choose a genetic algorithm (GA). An alternative was also proposed to solve the multiobjective problem with linear programming, by linearizing it under constraint. This work has highlighted the necessity of developing an effective recycling field of wastes from electric and electronic equipment in France. It also showed that the copper contained in wastes does not meet the demand, so that France needs to import copper, preferably as scraps.
172

Abastecimento de materiais numa linha de montagem final multiproduto / Material supply in multiproduct final assembly line

Rodrigues, Márcio Garcia [UNESP] 21 April 2016 (has links)
Submitted by MÁRCIO GARCIA RODRIGUES null (marciogarcia@maxionsc.com) on 2016-04-28T15:54:31Z No. of bitstreams: 1 Dissertacao_Marcio Garcia_280416.pdf: 2456536 bytes, checksum: b79ef40cb702a054ccb7d7f939704cf6 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-02T12:54:04Z (GMT) No. of bitstreams: 1 rodrigues_mg_me_guara.pdf: 2472389 bytes, checksum: 1c7d0b1b7f5b2d9c139a65d762cda63a (MD5) / Made available in DSpace on 2016-05-02T12:54:04Z (GMT). No. of bitstreams: 1 rodrigues_mg_me_guara.pdf: 2472389 bytes, checksum: 1c7d0b1b7f5b2d9c139a65d762cda63a (MD5) Previous issue date: 2016-04-21 / A crescente variedade de produtos nos sistemas atuais de produção é um grande desafio para a logística interna de abastecimento de materiais numa linha de montagem final, o abastecimento logístico precisa estar em concordância com a programação de produção de forma a disponibilizar para montagem o material necessário, no momento certo e na quantidade correta. A linha de montagem objeto do estudo acompanha esta tendência. Nela são montados modelos variados de chassis. Desta forma, o objetivo geral da pesquisa é desenvolver um modelo de abastecimento para linha de montagem multiprodutos, onde o ponto principal do trabalho é a definição do conceito mais adequado de acordo com o tipo e quantidade do material a ser abastecido. Através de uma pesquisa-ação foi proposto um modelo de abastecimento de linha que demonstrou uma redução de aproximadamente 50% da área ocupada na borda de linha, em consequência da redução de materiais, e aumento de 3% da produtividade, em virtude das reduções das indisponibilidades e perdas por set-up de abastecimento. / The increasing variety of products in current production systems is a big challenge for internal logistics supply of materials to a final assembly line, the logistic supply must be in step with the production program, in order to provide the necessary material for assembly at the right time and in the correct quantities. The assembly line which is the object of this study follows the trend. On it, several models of chassis are assembled. Therefore, the general objective of this research is to develop a supply model for a multi-product assembly line, with the main focus of the work on determining the most suitable concept in terms of the type and amount of material to be supplied. Through research-action, a model to supply the line has been proposed, which demonstrated a reduction of approximately 50% of the area occupied alongside the line, due to the reduction in materials, and an increase of 3% in productivity, owing to the reductions in outages and losses during supply set-up.
173

Organizace výroby a práce ve vybraném zemědělském podniku / Organization of production and work in the chosen agricultural enterprise

VRZAL, Karel January 2008 (has links)
The thesis contains analysis of organization and control structure of the agricultural enterprise and analysis of some logistics branches such as material-flow, manipulation with material, storing and relation between customers and suppliers. According to the realized analyses, arrangements are suggested to solve problems and to improve the contemporary situation in analyzed branches.
174

Řízení dodavatelského řetězce / Supply Chain Management

KUBÍKOVÁ, Klára January 2008 (has links)
Logistics is a discipline that deals with material flow and related information and financial flow, namely from a raw materials supplier via a producer and other intermediators to an end user. And all this with the goal to maximally satisfy customer needs for reasonable costs within the whole chain. Supply chain management is one of the strategies of the modern management that deals with the optimization of all activities and systems in order to secure the whole corporate chain. The company Masna Příbram uses an integrated information system that provides each segment of the supply chain with information on a daily basis. As the chain is managed by one owner, it is possible to plan and realize the production in accordance with the real demand of the segments along the chain flow. The result is that no goods are stored and if they are then only in minimum quantity.
175

Logistické zajištění výroby betonových směsí / Logistics assuring of concrete mixtures production

BOBEK, Stanislav January 2009 (has links)
Diploma paper is dealing with complex analysis of the information and material flows in concrete mixtures production focusing on proposals of logistic cost optimalization. The complex analysis is based on the time and direct observation in selected subject. One part of this work is dealing with optimalization of supply of production raw materials especially self supply of gravel aggregate into the each concrete mixing plant. Second part of this work is dealing with selected subject fleet optimalization. Optimalization possibilities were based on the results of the comprehensive analysis of the information and material flows.
176

Analise do ciclo de vida da soja / Life cycle assesment of soybean

Cavalett, Otavio 10 August 2018 (has links)
Orientador: Enrique Ortega Rodriguez / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-10T19:25:37Z (GMT). No. of bitstreams: 1 Cavalett_Otavio_D.pdf: 1768365 bytes, checksum: 167e95b088960c318d1d668f8a548c6b (MD5) Previous issue date: 2008 / Resumo: O objetivo deste trabalho de pesquisa é avaliar o ciclo de vida da soja para quantificar as contribuições ambientais e econômicas necessárias em cada etapa de produção, transporte e processamento de soja e seus principais produtos. Para tanto, foram utilizadas a análise de energia incorporada, a análise de intensidade de materiais e a análise emergética, além de indicadores econômicos e sociais. Os resultados mostram que produção agrícola da soja é a etapa que utiliza maior quantidade de recursos no ciclo de vida dos produtos considerados: farelo de soja exportado para a Europa, biodiesel e óleo de soja refinado. Por isso, esta é a etapa agrícola é aquela que requer mais atenção dos tomadores de decisões em políticas publicas para um ciclo de vida da soja mais sustentável. Os resultados mostram que a produção de biodiesel de soja convencional não é uma alternativa sustentável (renovabilidade = 31%) para fornecimento de energia para a sociedade e também que os fluxos de farelo de soja exportados para a Europa são responsáveis por grandes impactos ambientais (índice de carga ambiental = 2,83). Entretanto, os resultados obtidos mostram que a soja pode ser produzida em sistemas alternativos mais sustentáveis de forma a reduzir estes impactos negativos / Abstract: The objective of this study is to assess the soybean life cycle to quantify the environmental and economic contributions at each stage of soybean and soybean products production, transport and processing phases. In order of that, it were used the Embodied Energy Analysis, the Material Intensity Analysis and the Emergy Synthesis as well other economic and social indicators. The results showed that agricultural production stage is the phase that uses larger amount of resources in the life cycle of soybean products considered: soy meal exported to Europe, biodiesel and refined soy oil. Therefore, the agricultural phase requires more attention of decision-makers for public policies toward a more sustainable soybean chain. Quantitative indicators showed that biodiesel production from conventional soybean is not a sustainable (renewability = 31%) alternative for energy supply to the society. Also, the soy meal flows exported to Europe are responsible for high environmental damages (environmental loading ratio = 2.83). However, the results showed that soybean can be produced in more sustainable alternative systems in order to reduce these negative impacts / Doutorado / Doutor em Engenharia de Alimentos
177

Carbon dioxide and Energy flows in Jämtland’s waste sector

Eriksson, Anna January 2016 (has links)
The aim of this study is to assess the current situation of energy and carbon flows through the waste sector in Jämtland. An energy flow analysis is performed by balancing the inflows and outflows of the lower heating value and embodied energy. A carbon flow analysis was made on the same principles although with the carbon content and embodied CO2eq.  The results are showing that over a period of one year, 75 000 tons of waste flows through the waste sector in Jämtland. Approximately 60 % of all the waste is incinerated. The energy analysis shows that 970TJ flows through the waste sector every year. Household waste is the category with most energy consumption and emissions in total. However, other materials like metal and electronics have higher energy and carbon content per ton than the household category. The results of the analyses can further be implemented in the Sustainable Jämtland model and it can then be used as a base when making strategies for a sustainable waste treatment.
178

Utilização dos conceitos de modelagem e de sistemas a eventos discretos em processos logísticos na indústria de máquinas /equipamentos / The use of the concepts of modeling and discrete event systems in logistics processes in industry machinery/equipment

Julio Henrique Pimentel Medrano 28 May 2011 (has links)
O presente estudo apresenta a reorganização do projeto de trabalho de uma indústria produtora de equipamentos para compressão de GNV, apoiada pelo uso de sistemas a eventos discretos (SED). A empresa em questão, pioneira neste segmento na América Latina, viveu um súbito aumento na demanda de mercado que expôs fragilidades em seu sistema logístico. Problemas associados ao planejamento e controle de estoque e fluxo de materiais tornaram-se evidentes e deveriam ser resolvidos para que não prejudicassem o fluxo de vendas da empresa. Devido a complexidade existente no projeto produtivo, a simulação foi considerada como a maneira mais segura de planejar alterações nas práticas administrativas e produtivas, sem interferir na rotina da empresa. A modelagem realizada neste trabalho foi feita a partir da construção de uma cadeia de valor para o processo produtivo.Tal abordagem permitiu identificar diversos fatores que contribuíam diretamente à falta de eficiência da empresa tais como a ausência de um sistema logístico estruturado: interligação deficiente entre determinados setores administrativos e a manufatura, formação de estoques paralelos, perda excessiva por manuseio, retrabalho ou uso incorreto de componentes (hidden factory). A modelagem e a análise das propriedades dos modelos foram validadas por meio de um sistema de gestão integralizado (ERP) trabalhando com base em dados reais da empresa estudada. O estudo revelou oportunidades de melhoria baseado na reorganização da seqüência de fabricação e de abastecimento de materiais, aumento de produtividade através de realocação da mão-de-obra, organização do local de trabalho e padronização das atividades. As melhorias identificadas no estudo exploratório e na simulação foram consolidadas formando um sistema de gestão customizado para a empresa objeto do estudo. / This study presents the reorganization of the project work of an industry producing equipment for compressed natural gas (CNG), supported by the use of discrete event systems (DES). The company in question, a pioneer in this segment in Latin America, experienced a surge in market demand that has exposed weaknesses in their logistics system. Problems associated with planning and inventory control and material flow have become evident and should be resolved not to damage the flow of the companys sales. Because of the complexities that exist in productive project, the simulation was considered the safest way to plan changes in administrative and productive practices, without interfering with the routine. The modeling performed in this work was done from the construction of a value chain for the production process. This approach has identified several factors that contributed directly to the inefficiency of the company such as the absence of a structured logistics system: poor interconnection between certain administrative sectors and the manufacture, stockpiling, parallel loss by excessive handling, rework or incorrect use of components ("hidden factory"). The modeling and analysis of the properties of the models were validated by means of a management system (ERP) work based on real data of the studied company. The study revealed opportunities for improvement based on the reorganization of the sequence of manufacturing and supply materials, increased productivity through reallocation of labor, work, workplace organization and standardization activities. The improvements identified in the exploratory study and simulation were consolidated to form a customized management system to the company object of study.
179

MBSE-Ansatz für eine Vernetzte Stoffstrommodellierung zur Verbesserung der Partnersuche in der Kreislaufwirtschaft

Wieck, Franz, Kronenberg, Philipp, Löwer, Manuel 07 September 2021 (has links)
Globale Krisen, Rohstoffengpässe oder Preisschwankungen stellen die globalisierten Lieferkettensysteme der westlichen Produzenten vor große Herausforderungen. Das Konzept der Kreislaufwirtschaft ist eine Möglichkeit, sich angesichts dieser Herausforderungen robuster zu positionieren, um weniger abhängig von äußeren Einflüssen zu sein. Die größte Hürde bei dem Aufbau von Netzwerken für Kreislaufwirtschaftsprozesse ist die Identifikation von potentiellen Partnern auf Basis von Stoffstrommodellen. Ein erfolgreiches Mapping ist von vielen Faktoren abhängig. Aktuell existiert kein Ansatz, um die Stoffströme so zu modellieren, dass die Darstellung und Berechnung für eine Partnersuche in der Kreislaufwirtschaft geeignet ist. Um der Komplexität, sowohl der Stoffstrommodellierung, als auch der Partnersuche gerecht zu werden, wird hier ein MBSE-Ansatz gewählt - ein überlegener Modellierungsansatz im Detaillierungsgrad und der Adaptionsfähigkeit. Das Modell verknüpft die 3 Hauptelemente der Wertstromanalyse (Produktionsprozess, Materialfluss und Geschäftsprozess) und ermöglicht dadurch neuartige Kennzahlen zu ermitteln. Diese Kennzahlen und die detaillierte Modellierung schaffen eine verbesserte Informationslage, auf Basis derer die Effektivität der Partnersuche in der Kreislaufwirtschaft signifikant gesteigert wird. Nach einer theoretischen Herleitung der Modellierungslogik und der Erweiterung des bestehenden Ansatzes der nachhaltigen Wertstromanalyse (engl. Sustainable Value Stream Mapping – Sus-VSM) wird anhand eines Beispiels das MBSE-Modell implementiert und validiert. Dieser MBSE-Ansatz besitzt das Potential, die Beschreibung industrieller Produktions- und Herstellungsprozesse erheblich zu verfeinern und dadurch Analysen und Berechnungen zu optimieren, was zu einer besseren Vernetzung der Industrie führt. Die dadurch identifizierten industriellen Symbiosen fördern die Kreislaufwirtschaft maßgeblich und helfen Ressourcen nachhaltiger zu nutzen.
180

Projektování logistických řetězců pomocí počítačové simulace / Planning of logistics processes by computer simulation

Sedláček, Martin January 2017 (has links)
Contents of this diploma thesis is creating of the simulation model of the logistic chain of the internal transport to evaluation of the impacts of the projected changes of the parameters of the logistic chain. The simulation model is created in Plant Simulation software by association Siemens PLM Software. An analysis of the discussed area is also included in the thesis. With the help of the simulation model it is tested if the modification of the logistic chain elements has positive impact on important characteristics of production of the given area. Conclusion are made from the results of the experiments and a modification of the logistic chain is suggested.

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