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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.
121

Infra-estrutura produtiva: uma sistematização dos métodos, técnicas e modelos para análise de desempenho / Productive infrastructure: a systemization of the methods, techniques and models to analyze frontier efficiency

Almeida, Mariana Rodrigues de 26 February 2007 (has links)
Com maior vigor nas últimas décadas do século XX, a eficiência das atividades estatais passou a ser contestada por múltiplos atores sociais, que tomam como paradigma de gestão os resultados alcançados pelo setor privado. Nesse novo cenário, emergiram movimentos globais de reforma do aparelho estatal, a fim de impor às atividades públicas a eficiência com que supostamente atua o mercado, uma vez que o debate acerca da eficiência do capital público é uma questão de grande relevância para o campo de estudo relativo às diversas áreas do conhecimento, às atividades macro e microeconômicas e à própria dinâmica social. Conseqüência dessa atenção crescente destinada à análise, e contestação, da eficiência do gasto público e das atividades a ele imbricadas, é a histórica institucionalização, pela legislação brasileira, da eficiência como um dos princípios fundamentais da administração pública, como propõem o decreto-lei n. 200/67 e a emenda constitucional n. 19/98. Nesse cenário, em que a eficiência das atividades públicas é crescentemente almejada e refutada, tomam projeção e relevância métodos e técnicas que tratam desse aspecto. Adquire importância, por conseqüência lógica, pesquisas destinadas a sistematizar as contribuições e experiências sobre a utilização de tais métodos. Entretanto, poucos trabalhos extrapolam o caráter meramente aplicativo das técnicas, explicitando-se a carência por bibliografia que sistematize, sob diversos aspectos, as aplicações já realizadas, nesse campo do conhecimento. Dessa forma, esta pesquisa objetiva identificar e sistematizar os métodos existentes para avaliar a eficiência dos investimentos públicos em infra-estrutura na literatura internacional e nacional. Contribui-se, portanto, com subsídios teóricos e analíticos para pesquisadores em gestão pública, administradores estatais e cidadãos que se ocupam com a análise da eficiência das atividades públicas, principalmente em infra-estrutura. / With larger energy in the last decades of the 20th century, the efficiency of the state activities passed to be answered by multiple social actors, that you/they take as administration paradigm the results reached by the private section. In this new scenery, global movements of the state\'s reform apparel emerged, in order to impose to the public activities the efficiency where supposedly the market acts, once the debate concerns the efficiency of the public capital is a subject of great relevance for the field of relative study to the several areas of knowledge, to activities macro and microeconomics and to the own social dynamics. The consequence of this growing attention destined to the analysis, and reply, the efficiency of the public expense and of those activities, that\'s the historical institutionalization, which for the brazilian legislation, of the efficiency as one of the fundamental beginnings in public administration, as they propose the law n. 200/67 and the constitutional amendment n.19/98. In this scenery, in what the efficiency of the public activities is increasingly longed for and refuted, they take projection and relevance methods and techniques that treat that aspect. It acquires importance, for logical consequence, researches destined to systematize the contributions and experiences about the use of such methods. However, few works extrapolate the character merely application of techniques, explicated if the lack for bibliography that systematizes, under several aspects, the applications already accomplished, in the field of knowledge. In that way, this objective research to identify and to systematize the existent methods to evaluate the efficiency of the public investments in infrastructure of the international and national literature. It is contributed, therefore, with theoretical and analytical subsidies for researchers in public administration, state administrators and citizens that are in charge with the analysis of the efficiency of the public activities, mainly in infrastructure.
122

Eficiência da braçada no nado crawl : atualização do estado da arte / The arm stroke efficiency in front crawl swimming : updating the state of the art

Silveira, Ricardo Peterson January 2016 (has links)
O tópico principal desta tese de doutorado foi a efficiência da braçada no nado crawl. A tese foi composta e dividida em três artigos originais, com o objetivo de: (1) investigar as relações existentes entre a eficiência da braçada e a potência de membros superiores na determinação da velocidade máxima do nado crawl, (2) estimar os efeitos da pernada na velocidade de nado e no cálculo da eficiência da braçada no nado crawl, e (3) comparar os diferentes métodos utilizados para estimativa da eficiência da braçada e identificar os principais preditores biofísicos da velocidade máxima em 200 m crawl utilizando apenas os braços. Diferentes métodos foram utilizados para quantificar a eficiência da braçada, como o modelo da “roda de pás” (estudos 1, 2, e 3), a razão entre a velocidade de nado e a velocidade deslocamento da mão (estudo 3), e o método utilizando o MAD System (estudo 3). A contribuição da pernada foi estimada individualmente, considerando as diferenças de velocidade de nado para uma determinada frequência gestual, em diferentes intensidades. Os componentes úteis e não-úteis para a potência mecânica total exercida pela braçada foram obtidos por meio de protocolos fora d’água (utilizando um ergômetro de brações específico; estudo 1) e dentro d’água (utilizando o MAD System; estudo 3), combinados com medidas fisiológicas e biomecânicas, incluindo a eficiência da braçada. A velocidade máxima em 200 m teve como determinantes o equilíbrio entre variáveis biomecânicas (75% das variâncias pôde ser explicado pela potência mecânica externa e a eficiência da braçada; 98% das variâncias pôde ser explicado pela potência mecânica externa, eficiência propulsiva e o coeficiente de arrasto) e variáveis fisiológicas (98% das variâncias pôde ser explicado pela potência metabólica total e o custo energético). Ainda, a contribuição da pernada para a velocidade de nado aumentou com o aumento da frequência de braçadas (e da velocidade). Assim, ajustes individuais relativamente à contribuição da pernada devem ser considerados no cálculo da eficiência da braçada ao se nadar o nado crawl “completo” (usando braços e pernas). Por fim, os diferentes métodos fornecem valores de eficiência significativamente diferentes, embora haja concordância entre os mesmos. Portanto, valores de eficiência da braçada devem ser interpretados com cautela, considerando o método utilizado. / The main topic of this thesis was the arm stroke efficiency in front crawl swimming. Hence, it was developed in three original articles aiming to: (1) investigate the interplay between propelling efficiency and arm’s power output in determining the maximal speed in front crawl swimming, (2) estimate the effects of leg kick on the swimming speed and on arm stroke efficiency in front crawl, and (3) to compare different methods to assess the arm stroke efficiency and to identify the main biophysical predictors of maximal speed in 200 m swimming with the arms only. Different approaches were used to quantify the arm stroke efficiency. For instance, the paddle-wheel model (studies 1, 2, and 3), the ratio forward speed/hand speed (study 3), and the MAD System approach (study 3). The leg kick contribution was estimated individually, considering the differences in speed at paired stroke frequencies, in a range of speeds. Useful and non-useful components of the total mechanical power exerted by the arm stroke were obtained from dry land (using a customized arm-crank ergometer; study 1) and swimming protocols (using the MAD System; study 3), combined to the assessment of physiological and biomechanical parameters, including the arm stroke efficiency. The maximal speed in 200 m was determined by the balance between biomechanical (75% of the variances explained by the external mechanical power and the arm stroke efficiency; 98% of the variances explained by the external mechanical power, the arm stroke efficiency and the speed-specific drag) and physiological parameters (98% of the variances explained by the total metabolic power and the energy cost of swimming). Moreover, leg kick contribution to forward speed increased from low to maximal stroke frequencies (and speeds) and individual adjustments to the leg kick contribution should be considered when assessing the arm stroke efficiency in “full front crawl stroke” front crawl. Furthermore, the different methods provided significantly different values of arm stroke efficiency, although they agreed with each other. Therefore, arm stroke efficiency data should be interpreted carefully, considering the method used.
123

U.S. electricity end-use efficiency: policy innovation and potential assessment

Wang, Yu 27 August 2014 (has links)
Electric end-use efficiency is attracting more and more attentions, but it remains unclear what factors are driving state policy innovations to improve energy efficiency. Controversy also exists over the effectiveness of energy efficiency programs. Several critical problems are facing the policymakers: what factors drive the states taking distinct strategies in policy innovation? Have state policies being able to improve energy efficiency in the past? And, will state policies remain relevant to future efficiency improvements? This dissertation tries to answer these important questions and assumes that policy innovation is relevant to energy efficiency. It first explores the factors that influence the adoption of energy efficiency policies using Internal Determinants models. Results suggest that internal state factors affect policy innovation, including state socioeconomic factors, state fiscal capacity, ideology, and constituent pressure. Policy innovations are found to be correlated with each other. This dissertation also evaluates the impact of policy innovation on energy efficiency by decomposing electricity productivity into activity, structure, and efficiency effects. The findings suggest that financial incentives and building codes have significant impacts on state electricity productivity. Other regulations tend to have mixed effects. In addition, an estimation of the achievable potential of energy efficiency suggests that policies will cost-effectively drive significant electricity savings in the future. Overall, this dissertation offers an in-depth diagnosis of the relationship between policy innovation and energy efficiency. It provides a rigorous statistical analysis covering the most important energy efficiency policies. It represents the first attempt to evaluate policy impact by decomposing electricity productivity. However, the statistical models and energy models are subject to limitations and future research is needed to improve the models.
124

Reducing environmental impacts of petroleum refining : a case study of industrial flaring

Alfadhli, Fahad Mohammed 04 October 2012 (has links)
Industrial flaring can have negative impacts on regional air quality and recent studies have shown that flares are often operated at low combustion efficiency, which exacerbates these air quality impacts. This thesis examines industrial flaring with the objectives of (1) assessing the air quality impacts of flares operating at a variety of conditions, (2) examining the extent to which improvements in flare operations could reduce emissions, (3) identifying opportunities for recycling flared gases in fuel gas networks, and (4) identifying opportunities for reducing the generation of flared gases, using the improved control of catalytic cracking operations as a case study. The work presented in this thesis demonstrates that flares operating at low combustion efficiency can increase localized ambient ozone concentrations by more than 15 ppb under some conditions. The impact of flares on air quality depends most strongly on combustion efficiency, the flow rates to the flares and the chemical composition (photochemical reactivity) of the emissions. Products of incomplete combustion and nitrogen oxides emissions from flaring generally had a smaller impact on air quality than unburned flare gases. The combustion efficiency at which a flare can operate can be constrained by the flare’s design. In a case study of an air-assisted flare, it was demonstrated that choices in blower configurations could lead to emissions that were orders of magnitude greater or less than those predicted using an assumed combustion efficiency of 98%. Designing flares with air-assist rates that can be finely tuned can significantly reduce emissions. Similarly, flaring can be reduced by integrating sources of waste gases into fuel gas networks. Analyses for a petroleum refinery indicated that this integration can often be accomplished with little net cost by expanding boiler capacities. Finally, flared gases can be reduced at their source. A case study of a fluid catalytic cracking indicated that using better temperature control could significantly minimize flared gases. / text
125

Water-use efficiency and productivity in native Canadian populations of Populus trichocarpa and Populus balsamifera

Pointeau, Virginie M. 05 1900 (has links)
Afforestation and reforestation programs utilizing available fields for biofuel production, carbon sequestration, and other uses linked to climate change are looking to tree physiologists to identify species and genotypes best-suited to their purposes. The ideal poplar genotype for use in Canadian programs would be drought-resistant, cold-climate adapted, and fast-growing, thus requiring an understanding of links between a variety of physiological traits linked to growth and productivity. This study examined the basis for variations in water-use efficiency within four selected populations of Populus trichocarpa and Populus balsamifera (2 provenances each). Each species included both a northern and a southern provenance. Correlations between water-use efficiency, nitrogen-use efficiency, ¹³C/¹²C isotope ratio, stomatal conductance, and overall productivity were evaluated. Gas exchange variables measured included net photosynthesis, transpiration rate, stomatal conductance, and intercellular CO₂ content. Water-use efficiency and ¹³C content across all genotypes were highly correlated. Results suggested that variation in water-use efficiency was primarily related to variation in stomatal conductance across all genotypes. Whereas differences in net photosynthesis in this study were not significant between species, P. balsamifera did reveal a higher average stem volume overall. Although variation in stomatal conductance was the major determinant of differences in water-use efficiency, positive correlations were found between ¹³C isotope abundance and net photosynthesis in both P. balsamifera provenances. In this regard, results for the northern P. balsamifera provenance are the most consistent across all gas-exchange and growth trait correlations, in terms of meeting expectations for sink-driven water-use efficiency. The findings in this study suggest the possibility of identifying poplar genotypes with an absence of trade-off between water-use efficiency and nitrogen-use efficiency, notably among genotypes from the northern P. balsamifera provenance, near Gillam.
126

Water-use efficiency and productivity in native Canadian populations of Populus trichocarpa and Populus balsamifera

Pointeau, Virginie M. 05 1900 (has links)
Afforestation and reforestation programs utilizing available fields for biofuel production, carbon sequestration, and other uses linked to climate change are looking to tree physiologists to identify species and genotypes best-suited to their purposes. The ideal poplar genotype for use in Canadian programs would be drought-resistant, cold-climate adapted, and fast-growing, thus requiring an understanding of links between a variety of physiological traits linked to growth and productivity. This study examined the basis for variations in water-use efficiency within four selected populations of Populus trichocarpa and Populus balsamifera (2 provenances each). Each species included both a northern and a southern provenance. Correlations between water-use efficiency, nitrogen-use efficiency, ¹³C/¹²C isotope ratio, stomatal conductance, and overall productivity were evaluated. Gas exchange variables measured included net photosynthesis, transpiration rate, stomatal conductance, and intercellular CO₂ content. Water-use efficiency and ¹³C content across all genotypes were highly correlated. Results suggested that variation in water-use efficiency was primarily related to variation in stomatal conductance across all genotypes. Whereas differences in net photosynthesis in this study were not significant between species, P. balsamifera did reveal a higher average stem volume overall. Although variation in stomatal conductance was the major determinant of differences in water-use efficiency, positive correlations were found between ¹³C isotope abundance and net photosynthesis in both P. balsamifera provenances. In this regard, results for the northern P. balsamifera provenance are the most consistent across all gas-exchange and growth trait correlations, in terms of meeting expectations for sink-driven water-use efficiency. The findings in this study suggest the possibility of identifying poplar genotypes with an absence of trade-off between water-use efficiency and nitrogen-use efficiency, notably among genotypes from the northern P. balsamifera provenance, near Gillam.
127

The meanings of efficiency /

Alexander, Jennifer Karns. January 1996 (has links)
Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [275]-299).
128

Essays on industrial structure, technical change, employment adjustment, and technical efficiency

Zheng, Jinghai. January 1900 (has links)
Thesis (doctoral)--Göteborgs universitet, 1997. / Added t.p. with thesis statement and abstract, 1997. Includes bibliographical references.
129

Technical efficiency of Swedish district courts : - a stochastic distance function analysis

Ragipi Rushid, Ajsuna January 2018 (has links)
The aim of this study is to measure Swedish district courts’ technical efficiency for the period between 2000 and 2016 by applying the stochastic distance function approach. Although a very important issue from a policy perspective, a few studies have measured the efficiency of the courts. The narrow literature is also limited to using nonparametric methods, such as the DEA. The stochastic distance function has not been used for this purpose before and hence this is the first study to do so. The estimated mean score of technical efficiency is 93%. However, this study observes that efficiency levels increase throughout the studied period. Large variations between efficiency levels of different courts are also observed. Policy recommendations are to learn from courts with higher efficiency levels.
130

Eficiência da braçada no nado crawl : atualização do estado da arte / The arm stroke efficiency in front crawl swimming : updating the state of the art

Silveira, Ricardo Peterson January 2016 (has links)
O tópico principal desta tese de doutorado foi a efficiência da braçada no nado crawl. A tese foi composta e dividida em três artigos originais, com o objetivo de: (1) investigar as relações existentes entre a eficiência da braçada e a potência de membros superiores na determinação da velocidade máxima do nado crawl, (2) estimar os efeitos da pernada na velocidade de nado e no cálculo da eficiência da braçada no nado crawl, e (3) comparar os diferentes métodos utilizados para estimativa da eficiência da braçada e identificar os principais preditores biofísicos da velocidade máxima em 200 m crawl utilizando apenas os braços. Diferentes métodos foram utilizados para quantificar a eficiência da braçada, como o modelo da “roda de pás” (estudos 1, 2, e 3), a razão entre a velocidade de nado e a velocidade deslocamento da mão (estudo 3), e o método utilizando o MAD System (estudo 3). A contribuição da pernada foi estimada individualmente, considerando as diferenças de velocidade de nado para uma determinada frequência gestual, em diferentes intensidades. Os componentes úteis e não-úteis para a potência mecânica total exercida pela braçada foram obtidos por meio de protocolos fora d’água (utilizando um ergômetro de brações específico; estudo 1) e dentro d’água (utilizando o MAD System; estudo 3), combinados com medidas fisiológicas e biomecânicas, incluindo a eficiência da braçada. A velocidade máxima em 200 m teve como determinantes o equilíbrio entre variáveis biomecânicas (75% das variâncias pôde ser explicado pela potência mecânica externa e a eficiência da braçada; 98% das variâncias pôde ser explicado pela potência mecânica externa, eficiência propulsiva e o coeficiente de arrasto) e variáveis fisiológicas (98% das variâncias pôde ser explicado pela potência metabólica total e o custo energético). Ainda, a contribuição da pernada para a velocidade de nado aumentou com o aumento da frequência de braçadas (e da velocidade). Assim, ajustes individuais relativamente à contribuição da pernada devem ser considerados no cálculo da eficiência da braçada ao se nadar o nado crawl “completo” (usando braços e pernas). Por fim, os diferentes métodos fornecem valores de eficiência significativamente diferentes, embora haja concordância entre os mesmos. Portanto, valores de eficiência da braçada devem ser interpretados com cautela, considerando o método utilizado. / The main topic of this thesis was the arm stroke efficiency in front crawl swimming. Hence, it was developed in three original articles aiming to: (1) investigate the interplay between propelling efficiency and arm’s power output in determining the maximal speed in front crawl swimming, (2) estimate the effects of leg kick on the swimming speed and on arm stroke efficiency in front crawl, and (3) to compare different methods to assess the arm stroke efficiency and to identify the main biophysical predictors of maximal speed in 200 m swimming with the arms only. Different approaches were used to quantify the arm stroke efficiency. For instance, the paddle-wheel model (studies 1, 2, and 3), the ratio forward speed/hand speed (study 3), and the MAD System approach (study 3). The leg kick contribution was estimated individually, considering the differences in speed at paired stroke frequencies, in a range of speeds. Useful and non-useful components of the total mechanical power exerted by the arm stroke were obtained from dry land (using a customized arm-crank ergometer; study 1) and swimming protocols (using the MAD System; study 3), combined to the assessment of physiological and biomechanical parameters, including the arm stroke efficiency. The maximal speed in 200 m was determined by the balance between biomechanical (75% of the variances explained by the external mechanical power and the arm stroke efficiency; 98% of the variances explained by the external mechanical power, the arm stroke efficiency and the speed-specific drag) and physiological parameters (98% of the variances explained by the total metabolic power and the energy cost of swimming). Moreover, leg kick contribution to forward speed increased from low to maximal stroke frequencies (and speeds) and individual adjustments to the leg kick contribution should be considered when assessing the arm stroke efficiency in “full front crawl stroke” front crawl. Furthermore, the different methods provided significantly different values of arm stroke efficiency, although they agreed with each other. Therefore, arm stroke efficiency data should be interpreted carefully, considering the method used.

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