• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 28
  • 23
  • 11
  • 10
  • 8
  • 4
  • 4
  • 4
  • 4
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 106
  • 30
  • 19
  • 17
  • 16
  • 14
  • 13
  • 13
  • 12
  • 11
  • 10
  • 10
  • 10
  • 10
  • 9
  • 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.
11

Material replenishment system

Andersson, Stefan, Elfvenfrost, Johan January 2016 (has links)
This thesis work has been written both for and in co-operation with the company IAC Group Gothenburg. The main purpose of the report is to find a new alternative material replenishment system which will improve the internal material flow and eliminate unnecessary work activities such as manual call offs. The aim is to find a new system to reduce the incidental costs incurred and improve customer service in quality and performance. Observations and interviews were conducted and an analysis of the current situation was made. Waste was identified in the form of unnecessary transport, specifically in milk runs, where time was spent looking for materials to be loaded. This creates uncertainty and may contribute to increased costs and poor customer service. Three different options for a new replenishment system were developed which were compared with the theory and present situation. The proposal was evaluated with respect to cost, available support, complexity and future compatibility. The analysis of the theory and current state shows the importance of a long-term solution with few risks of waste. The solution that best cope with this is an e-Kanban system that automates the replenishment system and would make manual material call offs disappear completely. The conclusion is that an e-Kanban system is the best long term option for a manufacturing company like IAC because it is highly adaptable to change, and can be integrated in the company’s ERP system. The recommendation is to implement a new e-Kanban system. First, it should be tested on a pilot station and then introduced to the whole production process.
12

Drug Metabolizing Enzyme, Drug Transporter Expression And Drug Disposition Are Altered In Models Of Inflammatory Liver Disease

Lickteig, Andrew Joseph January 2007 (has links)
Correct dosing in pharmacotherapeutics is based on the idea that too much of a drug will cause toxicity, while too little will result in failure to elicit the desired response. A major factor in the ability of a patient to handle any dose of a drug is the capacity to metabolize and eliminate that drug from the body. For the vast majority of drugs, the liver plays a key role in determining the rate at which drugs are eliminated. First, drugs must be taken up across the cell membrane into hepatocytes by uptake transporters. Once inside the hepatocyte, biotransformation enzymes metabolize and conjugate the drug to a more water-soluble compound, the distribution of which is more easily controlled. These water-soluble metabolites are then transported out of the hepatocyte by additional drug transporters either into bile for elimination, or back into the blood.More than 2 million severe adverse drug reactions occur in the US each year and often result from interindividual variation in the ability to metabolize and eliminate drugs. This number does not include medical errors, but rather circumstances where an individual is unable to handle the standard dose of the correctly prescribed drug. Although genetics plays an important role, the greatest source of variation comes from other environmental factors such as disease states. Nonalcoholic fatty liver disease (NAFLD) is a chronic condition that comprises a spectrum of histopathologies that range from simple steatosis to the more severe steatohepatitis. Specifically, nonalcoholic steatohepatitis (NASH) has become one of the leading causes for liver transplantation in the United States, and thus clearly become a considerable burden to the U.S. healthcare system.It is not known whether the capacity of the liver to metabolize and excrete drugs is altered in patients with NASH. Because the liver plays such a critical role in drug metabolism and disposition, any disease state that disrupts or modifies these functions will alter the fate of a given drug within the body. It is therefore very likely that the ability of the liver to metabolize and excrete clinically relevant drugs is compromised in NASH patients.
13

The Drosophila GW protein, a posttranscriptional gene regulator that influences progression through mitosis

Schneider, Mary Unknown Date
No description available.
14

Caractérisation de la relation entre le transporteur MRP2 et les récepteurs P2Y sur la réponse physiopathologique des cellules épithéliales intestinales / Caracterization of the relation between transporter MRP2 and P2Y receptors on the physiopathological response of intestinal epithelial cells

Vinette, Valérie January 2012 (has links)
Résumé: Suivant un stress inflammatoire, les cellules épithéliales intestinales (CE1s) relâchent des nucléotides extracellulaires, des molécules pro-inflammatoires qui activent les récepteurs purinergiques P2Y qui sont impliqués dans l'inflammation intestinale. Hormis les récepteurs P2Y, la famille des transporteurs MRP joue aussi un rôle dans l'inflammation intestinale et les maladies en découlant. Plus spécifiquement, MRP2 joue un rôle important dans l'expert de molécules inflammatoires et de drogues cytotoxiques hors des CEIs. Dans cette perspective, nous avons caractérisé en quoi la coopération du transporteur MRP2 avec les récepteurs P2Y pouvait influencer les fonctions des CEIs dans le cancer colorectal. La lignée cellulaire Caco-2 a été stimulée à l'aide de 100 p.M d'ATP ou d'UTP pendant 3 à 18 heures et l'expression de MRP2 et de P2Y2 a été mesurée par qPCR et par immunobuvardage. Nous avons par la suite vérifié s'il existe une relation entre l'expression de MRP2 et celle de P2Y2 dans les échantillons de tumeurs colorectales obtenus à partir de biopsies. D'un point de vue physiologique, nous nous sommes demandés si la modulation de l'expression de MRP2 par l'ATP pouvait conférer aux CEIs une résistance accrue face à divers agents chimiothérapeutiques. Nous avons également entamé une étude dans le but d'établir par quelle voie de signalisation l'activation du récepteur P2Y2 pouvait stimuler l'expression de MRP2. Nous avons démontré que la stimulation des CEIs par les nucléotides extracellulaires augmente l'expression de MRP2. La modulation de l'expression de MRP2 passe par l'activation du récepteur P2Y2 et semble impliquer la voie de signalisation MEK/ERK. De façon surprenante, nous avons observé que l'expression de l'ARNm de MRP2 est augmentée dans les tumeurs de cancer colorectal comparé au tissu sain, tandis que celle de P2Y2 est diminuée. Nous avons également démontré que la stimulation des CEIs par l'ATP augmente la résistance des cellules à l'étoposide et que l'invalidation du transporteur MRP2 diminue la survie des CEIs face à l'étoposide, le cisplatin et la doxorubicine. Finalement, notre analyse de l'expression de l'ARNm de P2Y2 nous a démontré que celle-ci est augmentée dans les CEls où MRP2 est invalidé. Ces résultats montrent clairement l'implication et la coopération du récepteur P2Y2 et du transporteur MRP2 dans le développement et la progression du cancer colorectal. Ils sont concordants avec les rôles de ce récepteur dans la prolifération cellulaire et l'inflammation intestinale, ainsi que ceux de MRP2 dans l'export de drogues cytotoxiques. // Abstract: Following an inflammatory stress, intestinal epithelial cells (IECs) release extracellular nucleotides, notably ATP and UTP, pro-inflammatory molecules that activate P2Y purinergic receptors that are involved in intestinal inflammation as well as a variety of cancers. Apart from P2Y receptors, the family of MRP transporters also plays a role in intestinal inflammation and in pathologies deriving from it. More specifically, MRP2 plays an important role in the export of inflammatory molecules and cytotoxic drugs from IECs. In this perspective, we studied the involvement and cooperation of MRP2 with P2Y 2 receptor in colorectal cancer. The Caco-2 cell line was stimulated with 100 µM ATP and UTP for a period of 3, 6 and 18 hours, whereafter the expression of MRP2 and P2Y2 was measured by real-time quantitative PCR and western blot. We then verified if there was a correlation between the mRNA expression of MRP2 and P2Y2 in biopsies obtained from patients with colorectal cancer. From a physiological standpoint, we wondered if the modulation of MRP2 expression by ATP could confer an increased resistance to IECs against chemotherapeutic agents. In this context, we began a study with the aim to establish by which signalization cascade the activation of P2Y 2 receptor could stimulate the expression of MRP2. We have demonstrated in this study that the stimulation of IECs with ATP and UTP increases the expression of MRP2, both at the transcriptional and protein level. The modulation of MRP2 expression occurs via the activation of the P2Y 2 receptor upon its stimulation with its agonists ATP and UTP, and the signaling cascade MEK/ERK seems to be implicated. In a surprising manner, we observed that the mRNA expression of MRP2 is increased in tumors of colorectal cancer compared to the healthy tissue while that of P2Y 2 is decreased. We have also demonstrated that the stimulation of IECs with ATP increases the resistance of cancer cells to the drug etoposide. On the contrary, the invalidation of MRP2 by shRNA decreases the survival of IECs against the chemotherapeutic agents etoposide, cisplatin and doxorubicin. Finally, our analysis of the mRNA expression of P2Y 2 has demonstrated that it is increased in IECs that are invalidated for the expression of MRP2. These results demonstrate an evident involvement and cooperation between extracellular nucleotides, P2Y2 receptor and MRP2 transporter in the development and progression of colorectal cancer. They are concordant with the role of this receptor in intestinal inflammation as well as that of MRP2 in the export of a variety of drugs. [symboles non conformes]
15

Evolution of human socio-cultural and ecological traits: a phylogenetic (supertree) approach / Evolution of human socio-cultural and ecological traits: a phylogenetic (supertree) approach

DUDA, Pavel January 2011 (has links)
Human species display complex intraspecies population structure and unparalleled behavioral and cultural diversity. In order to elucidate human population history and pattern of evolutionary change of socio-cultural and ecological traits, the first composite phylogenetic tree of 574 human populations (ethno-linguistic groups) was created on the basis of 129 recently published phylogenetic hypotheses based on genomic, genetic and linguistic data, utilizing supertree method matrix representation with parsimony. Subsequently, 56 selected socio-cultural and ecological characters based on ethnographic cross-cultural data were optimized on topology of obtained supertrees in order to reconstruct patterns of evolutionary change and states present in ancestral populations. The results are discussed in the light of recent studies of human phylogeography and cultural phylogenetic studies.
16

Simultaneous Lot sizing and Lead-time Setting (SLLS)Via Queuing Theory and Heuristic search

Muthuvelu, Sethumadhavan 23 January 2004 (has links)
Materials requirements planning (MRP) is a widely used method for production planning and scheduling. Planned lead-time (PLT) and lot size are two of the input parameters for MRP systems, which determine planned order release dates. Presently, planned lead-time and lot size are estimated using independent methodologies. No existing PLT estimation methods consider factors such as machine breakdown, scrap-rate, etc. Moreover, they do not consider the capacity of a shop, which changes dynamically, because the available capacity at any given time is determined by the loading of the shop at that time. The absence of such factors in calculations leads to a huge lead-time difference between the actual lead-time and PLT, i.e., lead-time error. Altering the size of a lot will have an effect not only on the lead-time of that lot but also on that of other lots. The estimation of lot size and lead-time using independent methodologies currently does not completely capture the inter-dependent nature of lead-time and lot size. In this research, a lot-sizing model is modified in such a way that it minimizes the combination of setup cost, holding cost and work-in-process cost. This proposed approach embeds an optimization routine, which is based on dynamic programming on a manufacturing system model, which is based on open queuing network theory. Then, it optimizes lot size by using realistic estimates of WIP and the lead-time of different lots simultaneously for single-product, single-level bills of material. Experiments are conducted to compare the performance of the production plans generated by applying both conventional and the proposed methods. The results show that the proposed method has great potential and it can save up to 38% of total cost and minimize lead-time error up to 72%. / Master of Science
17

A fábrica de skates: um caso didático em planejamento e controle da produção. / The skateboard factory: a teaching case for manufacturing planning and control.

Girotti, Leonel José 26 June 2013 (has links)
As altas exigências que impõe o mercado globalizado, a complexidade dos sistemas produtivos de manufatura atuais e os avanços na Tecnologia da Informação são fatos que resgatam a importância da Programação Detalhada da Produção para as empresas. A pesar de bastante consolidada e difundida, a abordagem clássica MRP / ERP não atende plenamente as necessidades em ambientes de produção intermitente. A Programação Detalhada da Produção com capacidade finita dos recursos, atualmente contemplada nos sistemas APS (Advanced Planning & Scheduling), constitui uma alternativa interessante para melhor cumprir prazos de entrega em ambientes com roteiros de produção complexos e produção make-to-order (MTO). O problema de pesquisa ora estudado contempla o ensino de modelos de Planejamento e Controle da Produção (PCP) em um ambiente de produção intermitente, com foco na Programação Detalhada da Produção e nos sistemas MRP e APS. Propõe-se um plano de ensino que busca apresentar e diferenciar essas abordagens. O plano contempla o uso de um caso didático A Fábrica de Skates. De uma forma lúdica, porém realista, o caso apresenta, nas suas cinco etapas, duas situações hipotéticas de uso de sistemas de programação. O primeiro, um MRP para planejamento da fábrica de skates e, no segundo, um APS utilizado pelo fornecedor de eixos. O plano foi aplicado pela primeira vez em uma turma de graduação do curso de Engenharia de Produção. Nesta dissertação, é apresentada uma descrição detalhada do caso didático, junto ao plano de ensino. A pesquisa verificou, mediante análise das atividades do caso e de um questionário de avaliação, a utilidade dos recursos elaborados, como também que as estratégias aplicadas ajudaram na aprendizagem. Nesta primeira aplicação, constatou-se também que a alta carga de trabalho dos alunos no semestre e o pouco peso dado à nota final do caso didático foram fatores que inibiram melhores resultados. Para futuras aplicações, o caso didático pode ser aprimorado: novas etapas contemplando outros assuntos importantes para a disciplina PCP e análise de alternativas para substituição dos softwares empregados são exemplos de melhorias. / The high standard of competition in global market, the complexity of current manufacturing systems and the advances in Information Technology highlight the importance of the detailed production scheduling. Although classical approaches such as MRP perform this function quite well in different situations, these systems do not perform well in make-to-order (MTO) production systems. The finite capacity scheduling currently embedded within the software called APS (Advanced Planning & Scheduling) is a more interesting approach to achieve better performance in meeting due dates in production environments with complex routings and MTO strategy. Thus, the problem addressed in this study concerns the teaching of Production Planning and Control (PPC) models for intermittent production, with focus on the detailed production scheduling using MRP and APS approaches. In order to that, a teaching plan is proposed to present and differentiate these approaches. It includes the use of an educational case study named \"The Skateboard Factory\". In a playful but realistic way, the case presents, in its five stages, two hypothetical situations of use of scheduling systems. First, an MRP approach for planning in the skateboard factory, and second, one APS approach used by the truck supplier. The teaching plan was first applied to an undergraduate degree Production Engineering program. In this dissertation, a detailed description of the educational case study, along with the teaching plan, is provided. The results achieved in the case study and the students evaluation attest to the usefulness of the resources designed, and also that the strategies applied really improved the learning process. In this first application, it was also observed that high workload and the little weight in the final grade of the case study inhibit better results. In future applications, the case can be enhanced to include new stages on other important issues of the PPC discipline and the replacement of the software used.
18

Análise do processo de entrega direta a produção em uma empresa de telecomunicações no Polo Industrial de Manaus

Montenegro Filho, Helido Guedes 02 June 2011 (has links)
Made available in DSpace on 2015-04-22T22:10:22Z (GMT). No. of bitstreams: 1 Helido Guedes Montenegro Filho.pdf: 2333644 bytes, checksum: 3a009dbcac0a54d285c882e1a0f92df4 (MD5) Previous issue date: 2011-06-02 / O presente trabalho é um estudo de caso no qual foi analisado um processo adotado por uma empresa no Polo Industrial de Manaus. O novo processo foi adotado em decorrência de circunstâncias especiais ocorridas junto aos fornecedores que possuem empresas no município de Manaus, e que ora realizam entregas de matérias-primas para a empresa. Foi implantado um processo que elimina a necessidade de comunicação baseado em dados manuais com os fornecedores, promovendo sincronia com a execução das linhas de manufatura, denominado de entrega direta à linha de produção (EDLP). Esta ferramenta habilitou o fornecedor entregar apenas certa quantidade de estoque necessário as ordens de produção, no momento correto da execução na linha de manufatura, evitando assim estoques desnecessários no armazém da empresa. Os fornecedores recebem os pedidos em ciclos de quatro horas, procedendo assim com suas entregas, na certeza que serão prontamente recebidos, sendo suas peças endereçadas diretamente às linhas de manufatura, para conclusão e adequação aos requisitos dos clientes finais da empresa. O método utilizado para estudar a aplicação do conceito do processo de entrega direta à linha de manufatura foi o Estudo de Caso, pois possibilitou a observação de uma realidade através de um método científico, havendo a necessidade de observar aspectos que validam o processo investigativo como, por exemplo, a confecção de um protocolo de pesquisa. Foi necessário elaborar um referencial teórico da literatura disponível sobre assuntos tais como; a Manufatura Enxuta e o uso de JIT e Kanban, a Produção Sincronizada e o uso do MRP e MRP II e no Suprimento Automático o uso de CRP e VMI. Ainda foi necessário elaborar uma pesquisa bibliográfica em assuntos como a utilização de ferramentas de tecnologia de informação (TI) na cadeia de suprimento, processos colaborativos de suprimento entre os quais se destaca o DSD (Direct Store Delivery). Os dados primários foram coletados através de aplicação de questionários individuais sobre o processo junto ao envolvidos de forma habilitar a comparação entre a teoria analisada e os fatos observados pelo público alvo da investigação. Os dados secundários foram levantados através dos procedimentos e instruções de trabalho referentes ao processo de entrega direta à linha de produção, provendo embasamento documental à pesquisa. Foram ainda analisados fluxos e mapas de processo sempre que disponíveis para consulta, tanto na empresa como nos fornecedores que atuam como parceiros. Portanto, baseado nos indícios levantados observou-se a validade das proposições retiradas da teoria. Após a análise do processo de entrega direta à linha de produção, compreende-se que este processo pode colaborar com a redução dos estoques de processo nas empresas através da promoção de um processo alinhado entre a forma como será executado o plano de produção, e a forma como os fornecedores são acionados e devem responder este chamado. Estes aspectos aliados a tecnologia da informação e um processo controlado de execução sincronizada favorecem o processo de entrega direta à linha de produção, levando a empresa a concluir que não há necessidade de manutenção de estoques intermediários desnecessários ao processo de produção realizado nas linhas de produção da empresa.
19

Implantação de sistemas de programação detalhada da produção: levantamento das práticas de programação da produção na indústria. / Implantation of systems of production scheduling: survey of the practical of the production scheduling in the industry.

Giacon, Edivaldo 08 July 2010 (has links)
Devido à grande pressão pela redução de estoques e prazos de entrega, concomitantemente com o aumento da variedade de produtos, o planejamento e controle da produção tem se tornado cada vez mais complexo e desafiador. Basicamente, essa atividade das empresas objetiva planejar e controlar o uso dos recursos produtivos, visando atender à demanda dos clientes. Tradicionalmente, a literatura tem abordado os sistemas MRP, KANBAN, OPT, mas um novo conjunto de soluções de sistemas de programação finita vem sendo crescentemente tratado. As empresas, na busca de aprimoramento para a atividade de PCP estão à procura de ferramentas de programação finita, também conhecidas como Advanced Planning and Scheduling (APS), a fim de melhorar o processo de gerenciamento de pedidos, incluindo quesitos como a determinação de prazos de entrega na etapa de negociação dos pedidos, programação efetiva dos pedidos firmes e controle da produção. Esta dissertação pretende verificar as necessidades e dificuldades da programação detalhada da produção, as barreiras de implantação e os benefícios dos APS. O método utilizado foi o levantamento survey nas empresas filiadas à Federação das Indústrias do Estado de São Paulo (Fiesp). Os resultados obtidos mostram que a programação detalhada da produção é uma atividade complexa para a maioria das empresas com estratégia de produção contra pedido (MTO), que estão direcionadas para aumento de desempenho estratégico. A grande maioria das empresas ainda utiliza o modelo de planejamento MRP, porém elas possuem objetivos que podem ser mais facilmente alcançados com o uso de sistemas APS. O aspecto financeiro ainda é limitador para aquisição de sistemas e falta de capacitação. / Due to the great pressure to reduce inventory and delivery, together with the increasing variety of products, production planning and control (PPC) has become increasingly complex and challenging. Basically, this activity aims business planning and control productive resources, to meet customer demand. Traditionally, the literature has addressed the systems MRP, KANBAN, OPT, but a new set of solutions of finite scheduling systems is increasingly being investigated. Companies in search of improvement to the activity of PPC are looking for finite scheduling tools, also known as Advanced Planning and Scheduling (APS) in order to improve the process of order management, including issues such as the determination of time delivery in the stage of negotiation of claims, effective scheduling of orders and production control. This study aims to ascertain the needs and difficulties in the detailed production scheduling, the stage of implementation, and benefits that APS software can provide. The research method was the survey in industries affiliated to the Federation of Industries of Sao Paulo (Fiesp). The results indicated that scheduling production is a complex activity for most companies under the make-to-order strategy (MTO). Companies are using MRPII planning model, but they have goals that can be more easily achieved with the use of advanced planning and scheduling systems (APS). This financial point is still limiting for acquisition of systems and lack of training.
20

A fábrica de skates: um caso didático em planejamento e controle da produção. / The skateboard factory: a teaching case for manufacturing planning and control.

Leonel José Girotti 26 June 2013 (has links)
As altas exigências que impõe o mercado globalizado, a complexidade dos sistemas produtivos de manufatura atuais e os avanços na Tecnologia da Informação são fatos que resgatam a importância da Programação Detalhada da Produção para as empresas. A pesar de bastante consolidada e difundida, a abordagem clássica MRP / ERP não atende plenamente as necessidades em ambientes de produção intermitente. A Programação Detalhada da Produção com capacidade finita dos recursos, atualmente contemplada nos sistemas APS (Advanced Planning & Scheduling), constitui uma alternativa interessante para melhor cumprir prazos de entrega em ambientes com roteiros de produção complexos e produção make-to-order (MTO). O problema de pesquisa ora estudado contempla o ensino de modelos de Planejamento e Controle da Produção (PCP) em um ambiente de produção intermitente, com foco na Programação Detalhada da Produção e nos sistemas MRP e APS. Propõe-se um plano de ensino que busca apresentar e diferenciar essas abordagens. O plano contempla o uso de um caso didático A Fábrica de Skates. De uma forma lúdica, porém realista, o caso apresenta, nas suas cinco etapas, duas situações hipotéticas de uso de sistemas de programação. O primeiro, um MRP para planejamento da fábrica de skates e, no segundo, um APS utilizado pelo fornecedor de eixos. O plano foi aplicado pela primeira vez em uma turma de graduação do curso de Engenharia de Produção. Nesta dissertação, é apresentada uma descrição detalhada do caso didático, junto ao plano de ensino. A pesquisa verificou, mediante análise das atividades do caso e de um questionário de avaliação, a utilidade dos recursos elaborados, como também que as estratégias aplicadas ajudaram na aprendizagem. Nesta primeira aplicação, constatou-se também que a alta carga de trabalho dos alunos no semestre e o pouco peso dado à nota final do caso didático foram fatores que inibiram melhores resultados. Para futuras aplicações, o caso didático pode ser aprimorado: novas etapas contemplando outros assuntos importantes para a disciplina PCP e análise de alternativas para substituição dos softwares empregados são exemplos de melhorias. / The high standard of competition in global market, the complexity of current manufacturing systems and the advances in Information Technology highlight the importance of the detailed production scheduling. Although classical approaches such as MRP perform this function quite well in different situations, these systems do not perform well in make-to-order (MTO) production systems. The finite capacity scheduling currently embedded within the software called APS (Advanced Planning & Scheduling) is a more interesting approach to achieve better performance in meeting due dates in production environments with complex routings and MTO strategy. Thus, the problem addressed in this study concerns the teaching of Production Planning and Control (PPC) models for intermittent production, with focus on the detailed production scheduling using MRP and APS approaches. In order to that, a teaching plan is proposed to present and differentiate these approaches. It includes the use of an educational case study named \"The Skateboard Factory\". In a playful but realistic way, the case presents, in its five stages, two hypothetical situations of use of scheduling systems. First, an MRP approach for planning in the skateboard factory, and second, one APS approach used by the truck supplier. The teaching plan was first applied to an undergraduate degree Production Engineering program. In this dissertation, a detailed description of the educational case study, along with the teaching plan, is provided. The results achieved in the case study and the students evaluation attest to the usefulness of the resources designed, and also that the strategies applied really improved the learning process. In this first application, it was also observed that high workload and the little weight in the final grade of the case study inhibit better results. In future applications, the case can be enhanced to include new stages on other important issues of the PPC discipline and the replacement of the software used.

Page generated in 0.0412 seconds