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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

Control methodology applied to national fishing strategies

Balance, Donald John January 1988 (has links)
No description available.
2

none

Chen, Yu-Cheng 25 January 2008 (has links)
In order to protect the biodiversity and the depleted marine resources, we should reserve them for future generations.Therefore, try to introduce the concept of Marine Protected Areas ( MPAs) which are based on ecosystem. It is divided into different kinds of protected areas to reserve the resources and protect the biodiversity and the completeness of natural habitats. MPAs offer the foundation of natural Sustainable Development. According to this research, and use the theory of resource economics basis to discuss the effective of MPAs. Then, it continued to discuss the effective of MPAs which is under negative uncertainty. According to the evidence of results, MPAs indeed can reap the benefit of our ecological at the same time , it also can maintain the effectiveness of MPAs.
3

Economic and environmental benefits from growing winter wheat in the Prairie Provinces: a bioeconomic approach

Solano-Rivera, Catalina Unknown Date
No description available.
4

The Impact of climate change on the optimal management of wetlands and waterfowl

Withey, Patrick 20 July 2012 (has links)
The Prairie Pothole Region (PPR) of Western Canada is characterized by productive cropland, grasslands, and millions of ‘potholes’ caused by receding glaciers. These potholes fill up with water and form wetlands habitat that is a rich and valuable ecosystem, and is one of the most productive waterfowl habitats in the world. However, the social benefits from wetland ecosystems are not paid to farmers, whose lands support wetlands, leading farmers in the PPR of Canada to drain wetlands. Wetlands habitat in the PPR is also threatened by climate change, due to potentially drier conditions, as well as biofuel policies that are aimed at mitigating climate change (which increase the value of grains relative to wetlands). This research is comprised of four empirical papers that study the optimal level of wetlands retention, as well as the effect of potential future climate change on wetlands. The methods employed include bioeconomic modeling, which maximizes an economic objective (utility of cropping, harvesting ducks) subject to biological constraints (wetlands and waterfowl retention), as well as positive mathematical programming to develop a land use model. In the first paper, a previous bioeconomic model of optimal duck harvest and wetland retention is updated and extended to include the nonmarket value of waterfowl and the ecosystem service and other amenity values of wetlands. Results indicate that wetlands and duck harvests need to be increased relative to historical levels. In the second paper, regression analysis is used to determine the casual effect of climate change on wetlands in the PPR. The model developed in the first paper is then adapted to solve the socially optimal levels of duck harvests and wetlands retention under current climate conditions and various climate change scenarios. Results indicate that the optimal number of wetlands to retain could decrease by as much as 38 percent from the baseline climate. In the third paper, the earlier bioeconomic model is extended to include cropping decisions. Further, the model is solved for disaggregated regions of the PPR. By including cropping decisions, this model can estimate the direct climate effects on wetlands and waterfowl management, as well as land use change due to biofuel policies. The model predicts that climate change will reduce wetlands by 35-56 percent from historic levels, with the majority of this change due to land use change. Wetlands loss is geographically heterogeneous, with losses being the largest in Saskatchewan. Finally, the fourth paper develops a multi-region Positive Mathematical Programming model that calibrates land use in the area to observed acreage in 2006. Policy simulations for both climate effects as well as the effects of biofuel policies determine how climate change will affect land use and wetlands. This model has the advantage of modeling the trade off between all major land uses in the area and is also solved on a region basis. Results indicate that climate change could decrease wetlands in this area by as much as 34 percent; the results are spatially heterogeneous. / Graduate
5

Economic and environmental benefits from growing winter wheat in the Prairie Provinces: a bioeconomic approach

Solano-Rivera, Catalina 11 1900 (has links)
Winter wheat fields provide upland nesting habitat for migrating birds. Duck nests built in winter wheat croplands experience lower probabilities of nest mortality due to farming practices compared to nests built in spring wheat croplands. Two dynamic optimization models are specified in order to measure economic (producer’s profit) and environmental benefits (mallard population) derived from increases in winter wheat acreage in the Prairies. The first model, maximizes the farmer’s revenue due to spring and winter wheat production, subject to mallard population dynamics. The second model uses a social planner point of view to maximize both the farmer’s revenue obtained from wheat production, and social benefit associated with mallard population. The connection between duck population and winter wheat is specified using a logistic growth function where the intrinsic growth rate is a function of winter wheat acreage, and carrying capacity sets the maximum numbers of ducks in a specific area. / Agricultural and Resource Economics
6

Sistemas de aquecimento automáticos na produção de frangos de corte

Catelan, Fernanda 16 February 2007 (has links)
Made available in DSpace on 2017-07-10T19:23:43Z (GMT). No. of bitstreams: 1 Fernanda Catelan.pdf: 917807 bytes, checksum: 1eb69893664d6f85f570a2e83ee5cc80 (MD5) Previous issue date: 2007-02-16 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The general aim of this research was to study the effects of different heating systems on the bioeconomic development of broilers from day 1 to day 45. The experiment was carried out during the winter of 2005, in commercial broiler houses located in western Paraná. The research was developed in a 1200 m2 broiler houses, with male broilers, from three different breedings, in the period between birth and slaughter on day 45, for each analyzed treatment. The adopted treatments for the economic evaluation of the different heating systems were automatic wood-burning system and automatic infrared gas system. The economic evaluation was made analyzing the energy consumption by the heaters in each treatment the gas the wood-burning through the bioeconomic index and the gross margin. The zootechnical indexes, which were evaluated, were the average weight gain and the feed consumption. The statistical data evaluation was by a randomized block in a factorial 2 X 3 model, two heating systems (automatic wood-burning and automatic infrared gas systems), three breedings broilers (A, B, C), made up by six treatments and six repetitions, totaling thirty-six broiler houses with thirteen thousand three hundred (13.300) birds each. The averages were analyzed by the Tukey test. For the general analyses of the results the Software Statistic® was utilized. The results showed that, in relation to energy consumption, the wood-burning system presented a higher energy consumption due to the lower heating power of wood, compared to the infrared gas system. Although the gas system has exhibited a higher production cost, it is still being used by the business owners. There was not a significant difference for the gross margin values and the bioeconomic index worked out for the different treatments. / O objetivo geral desta pesquisa foi o de estudar o efeito de diferentes sistemas de aquecimento sobre o desempenho bioeconômico de frangos de corte de um a 45 dias. O experimento foi realizado no período de inverno de 2005, em propriedades de produção industrial de frangos de corte, localizada no oeste do estado do Paraná. A pesquisa foi desenvolvida em aviários de 1200 m2, com frangos machos, de três linhagens diferentes, entre o nascimento e abate aos 45 dias, para cada tratamento estudado. Os tratamentos adotados para a avaliação econômica dos diferentes sistemas de aquecimento foram: sistema de aquecimento automático infravermelho a gás e sistema de aquecimento automático a lenha. A avaliação econômica foi realizada por meio de consumo de energia pelos aquecedores, a lenha e a gás, através da margem bruta e índice bioeconômico. Os índices zootécnicos avaliados foram: ganho médio de peso e consumo de ração. A avaliação estatística dos dados foi realizada, considerando o delineamento em blocos ao acaso em um modelo fatorial 2 x 3, dois sistemas de aquecimento (sistema de aquecimento automático infravermelho a gás e sistema de aquecimento automático a lenha), três linhagens de pintos machos (A, B e C), composto por seis tratamentos e seis repetições, perfazendo um total de 36 aviários com treze mil e trezentas (13.300) aves cada um. As médias foram analisadas através do teste de Tukey. Para a análise geral dos resultados, foi utilizado o Software Statistic®. Os resultados mostram que, em relação ao consumo energético, o sistema de aquecimento a lenha teve o maior consumo de energia, isso ocorre devido ao menor poder calorífico da lenha, em relação ao GLP. Porém, o sistema a gás apresentou maior custo de produção, mas continua sendo utilizado pelos avicultores. Não houve diferença significativa para os valores de margem bruta e para o índice-bioeconômico calculados para os diferentes tratamentos.
7

Sistemas de aquecimento automáticos na produção de frangos de corte

Catelan, Fernanda 16 February 2007 (has links)
Made available in DSpace on 2017-05-12T14:46:56Z (GMT). No. of bitstreams: 1 Fernanda Catelan.pdf: 917807 bytes, checksum: 1eb69893664d6f85f570a2e83ee5cc80 (MD5) Previous issue date: 2007-02-16 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The general aim of this research was to study the effects of different heating systems on the bioeconomic development of broilers from day 1 to day 45. The experiment was carried out during the winter of 2005, in commercial broiler houses located in western Paraná. The research was developed in a 1200 m2 broiler houses, with male broilers, from three different breedings, in the period between birth and slaughter on day 45, for each analyzed treatment. The adopted treatments for the economic evaluation of the different heating systems were automatic wood-burning system and automatic infrared gas system. The economic evaluation was made analyzing the energy consumption by the heaters in each treatment the gas the wood-burning through the bioeconomic index and the gross margin. The zootechnical indexes, which were evaluated, were the average weight gain and the feed consumption. The statistical data evaluation was by a randomized block in a factorial 2 X 3 model, two heating systems (automatic wood-burning and automatic infrared gas systems), three breedings broilers (A, B, C), made up by six treatments and six repetitions, totaling thirty-six broiler houses with thirteen thousand three hundred (13.300) birds each. The averages were analyzed by the Tukey test. For the general analyses of the results the Software Statistic® was utilized. The results showed that, in relation to energy consumption, the wood-burning system presented a higher energy consumption due to the lower heating power of wood, compared to the infrared gas system. Although the gas system has exhibited a higher production cost, it is still being used by the business owners. There was not a significant difference for the gross margin values and the bioeconomic index worked out for the different treatments. / O objetivo geral desta pesquisa foi o de estudar o efeito de diferentes sistemas de aquecimento sobre o desempenho bioeconômico de frangos de corte de um a 45 dias. O experimento foi realizado no período de inverno de 2005, em propriedades de produção industrial de frangos de corte, localizada no oeste do estado do Paraná. A pesquisa foi desenvolvida em aviários de 1200 m2, com frangos machos, de três linhagens diferentes, entre o nascimento e abate aos 45 dias, para cada tratamento estudado. Os tratamentos adotados para a avaliação econômica dos diferentes sistemas de aquecimento foram: sistema de aquecimento automático infravermelho a gás e sistema de aquecimento automático a lenha. A avaliação econômica foi realizada por meio de consumo de energia pelos aquecedores, a lenha e a gás, através da margem bruta e índice bioeconômico. Os índices zootécnicos avaliados foram: ganho médio de peso e consumo de ração. A avaliação estatística dos dados foi realizada, considerando o delineamento em blocos ao acaso em um modelo fatorial 2 x 3, dois sistemas de aquecimento (sistema de aquecimento automático infravermelho a gás e sistema de aquecimento automático a lenha), três linhagens de pintos machos (A, B e C), composto por seis tratamentos e seis repetições, perfazendo um total de 36 aviários com treze mil e trezentas (13.300) aves cada um. As médias foram analisadas através do teste de Tukey. Para a análise geral dos resultados, foi utilizado o Software Statistic®. Os resultados mostram que, em relação ao consumo energético, o sistema de aquecimento a lenha teve o maior consumo de energia, isso ocorre devido ao menor poder calorífico da lenha, em relação ao GLP. Porém, o sistema a gás apresentou maior custo de produção, mas continua sendo utilizado pelos avicultores. Não houve diferença significativa para os valores de margem bruta e para o índice-bioeconômico calculados para os diferentes tratamentos.
8

Caractéristiques biologiques spatialisées et influence des stratégies individuelles dans la gestion des ressources halieutiques : une approche par les jeux différentiels / Biological characteristics and spatial influence of individual strategies in the management of fishery resources : an approach based on differential games

Idda, Corinne 15 July 2014 (has links)
Une grande partie de la ressource halieutique est, à ce jour, surexploitée, voire menacée d’extinction. Il est donc nécessaire de gérer cette ressource de manière à assurer la viabilité du secteur économique de la pêche. L’objectif de ce travail est d’étendre et de compléter les modèles existant dans la littérature économique sur le sujet qui visent à analyser les effets de différentes stratégies de préservation de la ressource sur le profit du secteur de la pêche. Ces travaux souffrent en effet de deux limites principales.D’une part, ils mettent principalement en avant les caractéristiques biologiques de la ressource dans l’espace et leurs travaux se limitent généralement à la détermination du niveau de pêche qui assure le rendement soutenable maximal. Cependant, d’un point de vue économique, ces travaux sont limités puisqu’ils ne prennent pas en compte les interactions stratégiques entre agents.D’autre part, concernant les politiques de gestion de la ressource halieutique dans l’espace, peu de travaux intègre les stratégies individuelles des agents pour évaluer les impacts de ces règlementations sur l’état des stocks. De plus, en ce qui concerne les aires marines protégées, les travaux existant se concentrent sur les impacts de ce type de mesures sur les stocks de ressource et leur approche ne permet pas d’évaluer l’impact de la taille d’une aire marine protégée.Il est donc important d’élargir l’analyse dans deux directions. Tout d’abord, Nous allons tenter d’améliorer les travaux existants en y intégrant les stratégies des pêcheurs dans le cadre d’un secteur oligopolistique, (structure de marché représentative du secteur de la pêche), tout en prenant en compte les caractéristiques biologiques en termes de dispersion pour savoir dans quelle mesure ces différents aspects influencent les perspectives de préservation.Enfin, nous nous intéresserons, dans le même cadre d’analyse, aux politiques de gestion des ressources halieutiques pour évaluer leur efficacité. / Much of the fishery resource is, to date, overexploited even endangered. It is therefore necessary to manage this resource to ensure the sustainability of the fishery’s economic sector. The aim of this work is to extend and complete the existing models in the literature on the topic which aim for analyze the effects of different strategies for resource conservation benefit of the fishery sector. Indeed, these studies suffer from two main limitations.On the one hand, they put forward mainly the biological characteristics of the resource in space and their works are generally limited to the determination of the fishing level which provides the maximum sustainable yield. However, from an economic point of view, these works are limited, as they do not take into account the strategic behavior between agents.On the other hand, concerning the management policies of fishery resources in space, a few studies integrate agents’ individual strategies to evaluate the impacts of these regulations on the stocks state. In addition, with regard to marine protected areas, existing works focus on the impact of such measures on resources stock and their approach does not allow evaluating the impact of the size of a marine reserve.It is therefore important to extend the analysis in two directions. Firstly, we will try to improve existing works on integrating fishermen strategies in an oligopolistic sector (market structure representing the fishery sector), while taking into account the biological characteristics in terms of dispersion, to investigate in which extent these aspects influence the preservation prospects.Then, we focus, in the same analytical framework, the fishery resources management policies to evaluate their effectiveness.
9

Estimação de valores econômicos para características componentes de índices de seleção em bovinos de corte. / Estimation of economic values for component traits of selection indexes in beef cattle.

Ivan Borba Formigoni 07 February 2002 (has links)
O objetivo do presente estudo foi estimar valores econômicos para características componentes de índices de seleção em bovinos de corte na fase de cria. Os dados produtivos analisados foram simulados e representativos de sistemas de produção que fazem uso dos programas de melhoramento genético animal. Os valores de custos e receitas aplicados foram coletados de empresas ligadas ao setor econômico da pecuária de corte nacional. As características assumidas como critérios de seleção, para as quais estimaram-se valores econômicos, foram: probabilidade de prenhez aos 14 meses (PP14), habilidade de permanência (HP) e peso a desmama (PD). Para a estimação de valores econômicos, foi aplicada a metodologia de Modelo Bioeconômico, a qual estima o lucro adicional a partir da alteração no desempenho produtivo da característica de influência genética, enquanto mantendo constante todas as demais variáveis analisadas. O valor econômico da PP14 foi de R$0,71 por percentual de prenhez, avaliado por novilha e de R$1,16 por kg bezerro(a) desmamado, para a característica de PD. Os valores econômicos da HP, avaliados por vaca, foram de R$1,37, R$1,87, R$2,37 e R$2,87, considerando-se o custo de compra da novilha a R$450,00, R$500,00, R$550,00 e R$600,00, respectivamente. Os resultados econômicos obtidos foram padronizados para o valor genético-econômico, medida resultante do produto entre o desvio padrão genético aditivo da característica e o respectivo valor econômico. A HP, apesar de, em valores absolutos, ser a característica de maior importância econômica para o sistema produtivo analisado, apresenta o valor genético-econômico inferior em relação às características de PP14 e PD, as quais têm maior herdabilidade e variabilidade genética. O valor genético-econômico da soma das características PP14 e HP foi maior do que PD, sugerindo serem as características de fertilidade as mais economicamente importantes para o sistema produtivo simulado, específico ao comércio de bezerros desmamados para o mercado. / The objective of the present study was to estimate economic values for component of selection indexes in beef cattle herds during suckling phase. Analyzed productive data was simulated and representative of production systems assisted by breeding program. Values of costs and incomes were collected from companies related to the economical study of national cattle raising. Selection criteria, for which economic values was estimated, were: heifer pregnancy at 14 months (PP14), stayability (HP) and weight weaning (PD).) The methodology of Bioeconomic Model was applied to estimation of economic values (VE). This methodology estimates the impact in the profit from the alteration in performance for each trait of genetic influence, keeping constant all the others variables analyzed. The VE for PP14 was R$0.71 for percentage of heifer pregnant, evaluated for heifer, and R$1.16 for kg of calves weaned analyzed for PD. The VE of the HP, analyzed for cow, were R$1.37, R$1.87, R$2.37 and R$2.87 considering the heifer cost purchase of R$450.00, R$500.00, R$550.00 and R$600.00, respectively. The VE were standardized for the genetic-economic value, result of multiplication of additive genetic standard deviation of the trait by respective VE. Although HP, in absolute values, was the trait of larger economic importance to the analyzed productive system, it presents inferior genetic-economic value compared PP14 and PD. This inversion is due to greater heritability and genetic variability of PP14 and PD. The genetic-economic value of the PP14 and HP together, was more important than WW, showing that the traits of fertility are the most economically important for this simulated productive system, specific to the commerce of calves weaned for the market.
10

Ferramenta de gestão na pecuária leiteira: análise do investimento em melhorias para o bem-estar de vacas / Dairy Farming Management Tools: analysis of investment to the improvements of the cow\'s welfare

Ana Luiza Mendonça Pinto 30 July 2015 (has links)
Para suprir a crescente demanda pela produção de alimentos de origem animal baseada nos princípios do bem-estar, é importante que produtores de leite bovino se preocupem em identificar pontos fortes e fracos em seu sistema de produção, para que melhorias sejam realizadas, e sua manutenção neste mercado competitivo, favorecida. Sugere-se que há uma complementariedade entre aumento de produção causado por um melhor manejo (nutrição, instalações, controle sanitário etc.) e o aumento no nível de bem-estar animal - BEA. No entanto, percebe-se certa resistência dos pecuaristas para adoção de novas tecnologias e de instrumentos da administração e da gestão de empresas para proporcionar segurança nas tomadas de decisão de seu próprio negócio. Portanto, objetivou-se neste estudo, avaliar o retorno do investimento em melhorias para o bem-estar de vacas leiteiras em sistemas de produção em pasto e em confinamento. A partir da aplicação do protocolo de avaliação Welfare Quality® em seis unidades produtivas de leite bovino no estado de São Paulo, foram identificados pontos críticos de BEA a serem melhorados. Com base em um orçamento para realização dessas melhorias e em referências na literatura, foi estruturado um fluxo de caixa incremental para avaliação dos projetos de investimento em cada sistema produção. De acordo com os resultados obtidos para os parâmetros econômicos payback, valor presente líquido (VPL) e taxa interna de retorno (TIR), ambos os projetos de investimento foram considerados economicamente atrativos. Por fim, visando ao aprofundamento deste estudo, que relaciona aspectos técnicos com a viabilidade econômica na pecuária leiteira, utilizou-se da simulação de modelos de \"bioeconômicos\" para realização da análise de investimento em estratégias isoladas de melhorias. Pode-se concluir que o conjunto dos resultados obtidos de acordo com os três objetivos permitiu associar ferramentas de gestão que integram fatores técnicos, biológicos, sociais e econômicos em sistemas de produção de leite em pasto e em confinamento de acordo com esses estudos de caso. / To meet the growing demand for production of animal-based foods while emphasizing principles of animal welfare, dairy farmers should be motivated to identify the strengths and weaknesses in their production system. By analyzing their production system, improvements can be implemented in order to improve gains in a competitive market. It is suggested that there is a correlation between increased production due to better management of nutrition, facilities, sanitary control etc. with the increased levels of animal welfare (AW). Traditional dairy farmers are reluctant when trying to adopt new technologies and business-management tools which would aide in important decision-making to protect their most valued asset; their own business. Therefore, the objective of this study was to evaluate the return on investment in improvements to the welfare of dairy cows on pasture and in confinement systems. Based on the application of the Welfare Quality® evaluation protocol in six dairy farms in the state of São Paulo, critical points of AW for improvement were identified. Based on a budget to carry out these improvements and with references in available literature, an incremental cash flow for evaluation of investment projects in each of the two production systems was established. According to the results obtained through Payback economic parameters, net present value (NPV) and internal rate of return (IRR), both investment projects were considered economically attractive. Finally, in order to deepen this study which relates technical aspects with economic viability in dairy farming, bioeconomic simulation models were used to conduct the investment analysis in isolated strategies for improvement. Based on the three goas, it can be concluded that the use of tools that integrate technical, biological, social and economic aspects involved dairy production according with this study cases.

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