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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.
131

Impacto sócio-econômico da promoção de sementes de feijão miudo (Vigna unguiculata (L.) Walp) no município de São José do Norte/RS

Barum, Alexandre Oliveira 27 December 2002 (has links)
Made available in DSpace on 2014-08-20T13:44:29Z (GMT). No. of bitstreams: 1 tese_alexandre_oliveira_barum.pdf: 1404629 bytes, checksum: b4e524e85156305859bd71dbc36fd35b (MD5) Previous issue date: 2002-12-27 / The work was accomplished at the district of São José do Norte, RS and the objective was to study the seeds production system of cowpea (Vigna unguiculata (L.) Walp). It consisted of an evaluation of the economy of the district for the analysis of the production systems, which was accomplished in three stages. The first one consisted in producers characterization, with the purpose of identifying possible socioeconomical differences and use of technology. For this, correspondence analysis was used with nine quantitative and 33 qualitative characteristics. In the second stage there were used the static and dynamic aspects of three crop systems: (i) onion, (ii) isolated cowpea and (iii) mixed system, with three production factors: (i) financial resources, (ii) land and (iii) labor. For this evaluation the method called Petri s Net was used. In the third stage it was evaluated the economic impact of the seeds cowpea production in the region. In this case, the used method was denominated Leontief Matrix. The results demonstrated that the producers are homogeneous with relationship to its behavior. In the system analysis it was possible to observe that all system have, as the most limitant factor, financial sources. On the other hand, the mixed system is the one that showed a smallest index of resources sub-use, that represents a better use of the production potential. The system of seeds cowpea production has a small impact in the county economy, due to the volume of the regional economy being much greater in relation to cowpea business. However, the seeds cowpea production can double the income of the growers. / O objetivo da pesquisa foi estudar o sistema de produção de sementes de feijão-miúdo (Vigna unguiculata (L.) Walp) no Município de São José de Norte/RS, através de uma avaliação da estrutura econômica do município para posterior análise dos sistemas de produção, o que foi realizado em três etapas. A primeira etapa constou da tipificação dos produtores com finalidade de identificar possíveis diferenças quanto aos determinantes socioeconômicos ou na utilização de tecnologia. Para isto, foi usada análise fatorial de correspondência, com a utilização de nove características quantitativas e 33 características qualitativas. Na segunda etapa, foram avaliados aspectos estáticos e dinâmicos dos três sistemas existentes: cebola isolada, feijão-miúdo isolado e misto. Foram utilizados três fatores de produção: recursos financeiros, terra e mão de obra. Para esta avaliação utilizou-se o método denominado rede de Petri. Na terceira etapa, foi estimado o impacto econômico da produção de sementes de feijão-miúdo na região. Neste caso, o método utilizado foi denominado matriz insumo-produto. Os resultados demonstram que os produtores são homogêneos quanto ao seu comportamento. Na análise dos sistemas foi possível observar que: (i) todos têm como fator mais limitante os recursos financeiros; (ii) o sistema misto é que apresenta menor índice de subutilização dos recursos, representando um melhor aproveitamento do potencial de produção; (iii) o sistema de produção de sementes de feijão-miúdo apresenta um pequeno impacto na economia municipal, tendo em vista o volume de produção face ao volume total da economia; (iv) a produção de sementes de feijão-miúdo pode duplicar a renda dos produtores.
132

Sensitivity analysis of optimization : Examining sensitivity of bottleneck optimization to input data models

Ekberg, Marie January 2016 (has links)
The aim of this thesis is to examine optimization sensitivity in SCORE to the accuracy of particular input data models used in a simulation model of a production line. The purpose is to evaluate if it is sufficient to model input data using sample mean and default distributions instead of fitted distributions. An existing production line has been modeled for the simulation study. SCORE is based on maximizing any key performance measure of the production line while simultaneously minimizing the number of improvements necessary to achieve maximum performance. The sensitivity to the input models should become apparent the more changes required. The experiments concluded that the optimization struggles to obtain convergence when fitted distribution models were used. Configuring the input parameters to the optimization might yield better optimization result. The final conclusion is that the optimization is sensitive to what input data models are used in the simulation model.
133

ANÁLISE DE PASTAGENS DE CAPIM-ELEFANTE SUBMETIDAS AOS SISTEMAS DE PRODUÇÃO CONVENCIONAL E AGROECOLÓGICO COM BOVINOS LEITEIROS / ANALYSIS OF ELEPHANTGRASS PASTURES SUBMITTED TO CONVENTIONAL AND AGROECOLOGY PRODUCTION SYSTEMS WITH DAIRY CATTLE

Charão, Pablo Santini 23 March 2006 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The use of elephantgrass (EG) under grazing is basically done at conventional strategy. Information and research about its use in agroecology production systems are scarce. Then, the objective of this work was to compare the elephantgrass pasture dynamic and performance submitted to the conventional and agroecology forage production systems. Evaluation of animal behavior also has done during the winter period in agroecology pasture. In conventional system the EG was established in singular form with 1.4m of space between lines. In agroecology system the space between lines was of 3m. At this system, the mixture of oat and ryegrass in the winter period and spontaneous growing species in the summer period had been. The nitrogenous fertilization was of 150kg/ha/year and had been with organic and synthetics fertilizers to the pastures of agroecology and conventional systems respectively. Holstein lactating cows receiving 3.5kg/day of concentrate in rotational grazing and varied stocking rate were used to evaluation. The forage mass, leaf lamina biomass (LLBEG) and structural composition of EG, pastures botanical composition and stocking rate were evaluated. Samples of grazing simulation were collected to do the quality analyses. The forage mass, LLBEG and stocking rate were bigger in the conventional pasture. Considering the mean data of experimentation, the results of stocking rate were similar and had been of 695 and 614kg/ha respectively to conventional and agroecology production. At this system the utilization of oat and ryegrass and the spontaneous growing species allowed the forage availability to be uniformed during the grazings. At animal behavior analysis the highest intensity of grazing was registered after each milking, observing a decrease lately during the day as well as during the night. Diurnal grazing time was longer than nocturnal. The oat + ryegrass grazing time is highest at period that elephantgrass show smallest leaf lamina percentage. The time of idle decrease and the rumination increase during the grazings because the leaf lamina percentage decrease and stems percentage increase of winter period species. The elephantgrass was grazed at all evaluations. The presence of different cycles species propitiated opportunity to the animals balance the roughage diet. The agroecology as much as conventional system showed high qualitative values considering the fertilization, manage and utilization time, in proposed strategy. The results show that the EG can be used under the agroecology systematic proposed. / A utilização do capim-elefante (CE) sob pastejo, basicamente, é feita sob o sistema convencional. Informações e pesquisas sobre seu uso em sistemas de produção agroecológica são escassas. Os objetivos deste trabalho foram comparar a qualidade, a dinâmica e o desempenho de pastagens utilizadas segundo os sistemas de produção forrageira convencional e agroecológica e avaliar o comportamento animal no sistema agroecológico. No sistema convencional, o CE foi estabelecido singularmente, com espaçamento de 1,4 m entre as linhas. No sistema agroecológico, o espaçamento entre as linhas foi de 3 m. Neste fez-se a consorciação com aveia e azevém no período hibernal, e com as espécies de crescimento espontâneo no período estival. A adubação nitrogenada foi de 150 kg/ha/ano, com fertilizantes orgânicos e sintéticos para as pastagens nos sistemas agroecológico e convencional, respectivamente. Foram utilizadas vacas em lactação da raça Holandesa que receberam 3,5kg/dia de concentrado, em pastejo rotativo e lotação variada. Avaliou-se a massa de forragem, biomassa de lâminas foliares (BLFCE) e composição estrutural do CE, composição botânica das pastagens e carga animal. Foram coletadas amostras de forragem segundo o método manual, simulando o pastejo para posterior análise de composição química e digestibilidade in vitro. A massa de forragem, BLFCE e carga animal por pastejo foi maior no sistema convencional. Considerando-se os dados médios nos 375 dias de experimentação, os resultados da carga animal foram similares, sendo de 695 e 614 kg/ha, respectivamente para a produção convencional e agroecológica. Neste sistema, a utilização de aveia e azevém e das espécies de crescimento espontâneo de ciclo estival permitiram uniformizar a massa de forragem no decorrer dos pastejos. Houve maior intensidade de pastejo após cada ordenha, ocorrendo um decréscimo, posteriormente, tanto durante o dia quanto à noite. Em média, o turno que os animais pastejaram por mais tempo foi o diurno. O tempo destinado pelas vacas no consumo de aveia e de azevém é maior no período em que o capim-elefante apresenta menor percentagem de lâminas foliares. O tempo de ócio diminui e o de ruminação aumenta no decorrer dos pastejos devido ao declínio na porcentagem de lâminas foliares e elevação na porcentagem de colmos das espécies de ciclo hibernal. O capim-elefante foi pastejado em todas as avaliações. A presença de espécies de ciclos diferentes propiciou oportunidade aos animais para selecionarem a dieta volumosa em busca de um equilíbrio nutricional. Na estratégia proposta, tanto o sistema agroecológico quanto o convencional apresentaram teores qualitativos elevados, considerando-se a adubação, manejo e tempo de utilização. Os resultados demonstram que o CE pode ser utilizado segundo a sistemática agroecológica proposta.
134

Aide à la décision pour la servicisation des PME industrielles : une approche par modélisation et simulation / DECISION SUPPORT FOR SERVITIZATION OF INDUSTRIAL SMES : A MODELING AND SIMULATION APPROACH

Chalal, Malik-Eddine 03 October 2014 (has links)
L’évolution permanente de l’environnement de l’entreprise pousse les décideurs à s’inscrire dans un processus d’innovation. Nous assistons à une mutation des pratiques de certaines entreprises en intégrant de plus en plus une offre d’un système « produits-services ». Notre objectif, à travers cette thèse, est d’apporter une aide à la décision qui reposera sur la capacité à anticiper la performance du système en fonction de différentes décisions de gestion et face à différents types d’aléas lors de la servicisation. Le premier besoin d’aide à la décision est la nécessité de construire une démarche de modélisation et de simulation avec un modèle conceptuel du système de production orienté PSS. Pour cela nous avons proposé une décomposition de notre système entreprise orientée PSS en deux sous-systèmes : (i) Le sous-système d’usage et (ii) le sous système productif. Les deux sous-systèmes sont connectés et interdépendant. Un deuxième besoin qui apparait pour notre problématique est la construction d’un modèle simulable et exploitable. Nous avons utilisé la simulation à évènements discret afin de profiter de l’aspect « évènementiel » de cette approche et ainsi coupler entre le système d’usage et le système productif d’une part, et d’autre part entre les activités de services et les activités de production. Une application de notre démarche de modélisation et simulation sur un cas d’étude (Entreprise ENVIE) a été effectué et une analyses et interprétation des résultats suivies d’un ensemble de propositions de gestion pour une meilleure transition vers une offre PSS ont été apportées. / The ever-continuing evolution of business practices leads the decision-makers to develop strategies based on Innovative approaches. One of them is the transition to a product-services system, called servitization. The main goal of this thesis is to provide a decision support in order to anticipate the performance of a company when different transition management scenarios are implemented. The first step toward this objective is the formalization of a conceptual model of product-service systems. They consist of two subsystems: (i) user-oriented subsystem and (ii) production-oriented subsystem. These subsystems are connected and interdependent. The model developped in the second step of the thesis takes into account this coupling, whose influence on the overall performance of the company is assessed thanks to a discret-event simulation approach. Finally a case study is performed for a french SME (ENVIE) whose line of business is the re-manufacturing of electrical equipment. The analysis results highlight the main areas of improvement for the company, allowing a better transition to a product-service system.
135

Implicações agroeconômicas da cobrança pelo uso da água em sistemas de produção de arroz : uma simulação na área de abrangência da Barragem do Arroio Taquarembó – Dom Pedrito – RS

Pires, Paulo José da Fonseca January 2013 (has links)
O trabalho de pesquisa teve como referência o ano de 2011 e foi realizado na área da Barragem do Arroio Taquarembó, no Município de Dom Pedrito – RS. Esta região está localizada na microrregião da Campanha Gaúcha, inserida na Bacia Hidrográfica do Rio Santa Maria. O problema de pesquisa refere-se à possibilidade da cobrança pelo uso da água provocar um aumento significativo nos custos de produção da lavoura de arroz, inviabilizando sistemas de produção. Neste sentido, buscou-se identificar as possíveis mudanças no desempenho econômico dos sistemas de produção, com a implantação da cobrança pelo uso da água. A caracterização dos sistemas de produção agrícola foi realizada utilizando-se questionário, aplicado em todas as unidades de produção agrícola da área de estudo. Com as informações obtidas sobre a estrutura de produção, recursos humanos, financeiros e dos gastos e receitas na safra 2011, foram calculados indicadores de desempenho econômico. Para cada unidade de produção agrícola, foi determinado o consumo de água na lavoura de Arroz. O preço do metro cúbico de água foi obtido a partir de valores simulados por modelo matemático desenvolvido, especificamente, para a Bacia Hidrográfica do Rio Santa Maria. A partir do preço da água, foi determinado o custo de cada unidade de produção agrícola, em função do volume de água consumido. Após a inclusão deste novo custo de produção, foram recalculados todos os indicadores de desempenho econômico. Na sequência, foram realizadas análises estatísticas, visando identificar a existência de relação entre o estabelecimento da cobrança pelo uso da água e variações nos indicadores de desempenho econômico. As variações identificadas não foram estatisticamente significativas. Esta condição possibilitou concluir, para a região analisada, que a cobrança pelo uso da água pode não ser eficiente como desestímulo ao desperdício, pois não gera significativos impactos negativos na renda final dos produtores. Da mesma forma, também relativiza o argumento que a cobrança pelo uso da água inviabiliza a produção orizícola, pelo aumento excessivo dos custos de produção. / The research happened in 2011 at the Dam Arroyo Taquarembó, in Dom Pedrito - RS. This region is located in the micro Campaign Gaúcha inserted into the Santa Maria Basin River. The research problem concerns the possibility of charging for the water use caused a significant increase in production of the costs of the rice crop, preventing production systems. Therefore, to identify possible changes in the economic performance of production systems, with the deployment of charging for the water use. The characterization of agricultural production systems was conducted using a questionnaire applied to all agricultural production units of the researched area. With the information about the structure of production, human resources, and financial costs and revenues in 2011, it was calculated indicators of economic performance. For each unit of agricultural production, was given water consumption in rice farming. The price of a cubic meter of water was obtained from values simulated by a mathematical model developed, specifically, for the Santa Maria Basin River. From the price of water it was determined the cost of each unit of agricultural production, due to the volume of consumed water. After the inclusion of this new production costs it was recalculated all the indicators of economic performance. Further, statistical analyzes were performed in order to identify the existence of a relationship between the establishment of the charging for water use and the variations in economic performance indicators. The identified variations were not statistically significant. This condition allowed concluding, for the analyzed region, that the charging for water use may not be as effective disincentive to waste, because it does not generate significant negative impacts on the final income of producers. In this way, it wasn’t significant that the argument of the charging for water prevents the production of rice and the excessive increase of production costs, wasn´t significant.
136

System Evaluation and Learning in Evolvable Production Systems : Preliminary considerations and research directions

Neves, Pedro January 2012 (has links)
Dynamicity and unpredictability related to markets is strongly hardening companies’ mission to follow them and satisfy customer needs mainly due to the lack of adequate engineering mechanisms. These effects are felt more intensively in markets where low volumes and high customisation are needed since this requires constant changes in systems that can range from simple setups to total line re-configuration and re-programing. State of the Art Industrial technology has historically been driven to achieve very efficient and flexible production lines for pre-thought problems; however this technology doesn’t satisfy the needs faced by current production requirements where adaptability and responsiveness are off the essence. The last decade witnessed the advent of Evolvable Production Systems (EPS) and other modern paradigms that offer promising approaches to substitute obsolete production strategies. EPS enhances system re-configurability using process-oriented modularity and multi-agent based distributed control endowing the system with units that are autonomous, self-organizing and functionality-oriented. The aggregation of these independent units will then form a system that with a well-defined system architecture and interactions rules can collaborate to complete production plans and react to unpredictable events without re-programing needs. The complexity associated with combinatorial possibilities of forming a system based in such premises raises the need to study how such system performance can be evaluated and how machine learning can be used to discover best system configurations for specific cases. This thesis goal is to enlighten the relation between EPS characteristics, Evaluation and Learning building the foundations for the achievement of Evaluation and Learning mechanisms that can contribute to better system design and configuration to improve system performance and autonomy, and contribute to a more economical solution. / <p>QC 20121218</p>
137

Characterisation of Production Systems and Phenotypic Traits of Indigenous Chickens in Communal Areas of KwaZulu-Natal

Vilakazi, Bongiwe, Nontobeko 03 1900 (has links)
A thesis submitted the Department of Science and Agriculture in fulfilment of the requirement for the degree of Master of Science in the Faculty of Science and agriculture at the University of Zululand,2018 / Indigenous chicken genetic resources play a major role in rural communities. There is therefore a need for their sustainable use and conservation. Conservation requires knowledge of production systems, phenotypic and genetic characteristics. The aim of this study was to understand the production systems and phenotypic variation among indigenous chickens in some areas of KwaZulu-Natal. A survey was conducted in six districts of KwaZulu-Natal to characterise indigenous chicken production systems;, predict body weight from linear body measurements of indigenous chickens using principal component analysis, and identify the morphological variation among indigenous chicken populations. Small flock sizes ranging from 2 to 80 indigenous chickens were observed in households. The majority of farmers started rearing a few indigenous chickens sourced from related stock through inheritance, gifts and buying. Indigenous chickens were reared as a source of meat, eggs and income. Most farmers (72%), were not aware of the importance of conserving indigenous chickens. The most common constraints raised by farmers were diseases, predators and theft. The most commonly practised production systems were extensive and semi-intensive. Poor management in terms of feeding, watering and health was reported in all surveyed areas. Principal component analysis of linear body measurements extracted two principal components with a total variance of 63.94%. Principal component one, related to body size, had the largest share of breast circumference, body length and shank circumference. Principal component two, related to body shape, had high loadings on toe length, shank length and back length. The use of principal components was more appropriate than the use of original correlated variables in predicting the weight of indigenous chickens. Variation in morphological traits was observed; 10 plumage colours were realised from different locations, and variation was also observed in skin colour, eye colour, shank colour and comb type. Variation in phenotypes may reflect variation in the genome of the indigenous chickens. Discriminant analysis identified body weight as the most discriminating variable in differentiating indigenous chickens. Two major clusters were formed: the first by Newcastle, Port Shepstone and Cedara; the second by Pietermaritzburg and Ladysmith. Empangeni and Jozini individually joined the two clusters. Although Jozini showed itself to be more distant to the others, 51.1% of indigenous chickens were correctly assigned to their population. It was concluded that with the existing variation improvement in size and aesthetic characteristics of the indigenous chickens can be achieved through selection according to the needs of the farmers. Farmers require assistance on husbandry and management of indigenous chickens.
138

Vision system i utmanande miljöer / Vision systems in challenging environments : Developing guidelines for implementation of vision systems in the metal casting industry

Bohlin, Oskar, Hawil, Steven January 2023 (has links)
Companies strive to optimize their processes to increase productivity, efficiency, and quality in the production system. The complexity of different operations in a production system can vary, the level of complexity impacts the automation approach. The requirements of an automated solution increases with the level of complexity. A vision system is a type of automation solution which can improve the quality inspection process in many companies where the inspection process is performed manually. A challenge with implementing a vision system in different industries is that there are no general solutions. Depending on the requirements of an industry, the implementation of a vision system needs to be tailored to suit that industry. In this thesis, a case study is conducted in a foundry setting where empirical data is gathered through observations and interviews conducted with several departments. Nine parameters are identified which can affect the performance of a vision system in a metal casting environment. The identified parameters are analysed using relevant literature to find possible solutions. The result of the analysis is a set of guidelines which can be used when implementing vision systems in the metal casting industry and aims to mitigate possible negative effects of each parameter. A conceptual layout of a vision cell used to inspect cylinder heads based on the guidelines is also presented.
139

Development of a Reconfigurable Material Handling System

Lasslop, Nico, Samarakoon, Pawan January 2023 (has links)
No description available.
140

Energy and Production Planning for Process Industry Supply Chains

Waldemarsson, Martin January 2012 (has links)
This thesis addresses industrial energy issues from a production economic perspective. During the past decade, the energy issue has become more important, partly due to rising energy prices in general, but also from a political pressure on environmental awareness concerning the problems with climate change. As a large user of energy the industry sector is most likely responsible for a lot of these problems. Things need to change and are most likely to do so considering current and assumed future governmental regulations. Thus, the energy intensive process industries studied and focused on in this thesis exemplify the importance of introducing a strategic perspective on energy, an appropriate approach for planning, as well as the possibilities of including energy issues in a production and supply chain planning model. The thesis aims to provide models, methods and decision support tools for energy related production and supply chain planning issues of relevance for process industries as well as for other energy intensive industries. The overall objectives are to analyze the strategic importance of energy management, production and supply chain planning, and the opportunities provided when energy is included in a production and supply chain planning model. Three different studies are carried out, analyzed, and presented as in this thesis. The first study is a case study at a specialty chemicals company and resulted in the first paper. Since the energy issue is not only a cost issue driven by supply and demand, but also a political issue due to its environmental aspects, it is likely to believe that political influence and especially continuity will have escalating effect on the energy intensive process industry sector. Thus, the strategic dimension of energy is highly relevant in this thesis. The importance of organizational integration, having a main responsible person, locating core business, and political continuity are addressed as prerequisites for including energy into the corporate strategy. Regarding long term profitability, the importance of correctly utilizing the energy system by appropriate energy planning and with respect to energy efficiency and effectiveness in both flexibility and investment issues are addressed. Further on, the quest of finding alternative revenue while striving for a proper exergy usage is addressed. The second study is a multiple case study with four different case companies involved; pulp, specialty chemicals, specialty oils, as well as a pulp and paper company. The need for improved production and supply chain planning is also addressed where for instance the lack of planning support for process industries is still an area of improvement. The production and supply chain planning in process industries is found to be rather poor compared to regular manufacturing companies. The planning methods found are often tailor made and adapted to the individual characteristics that are typical for many process industries. It has further on been difficult to distinguish similarities and differences among process industries regarding these planning issues and thus hard to generalize. The third study focuses on mathematical modelling and programming developing a combined supply chain and energy optimization model for a pulp company. Taking the first papers together there are reasons to believe that a planning and optimization model that take energy aspects in consideration, as a previously missing link, will contribute to improve the operations in process industries. A clear impact of involving energy issues into the supply chain planning is shown. The results show that a different production schedule is optimal when the energy issues are applied, and depend on, for instance, variations in energy prices such as the one for electricity. This is shown by using a model for a supply chain where the energy flow, and especially the utilization of by-products, also is involved.

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