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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.
141

Long-run incremental cost pricing for improving voltage profiles of distribution networks in a deregulated environment

Matlotse, Edwin January 2010 (has links)
Electricity network pricing approaches play a fundamental role in establishing whether providing the network service function is economically beneficial to both the network operators and other stakeholders, namely, network users. Many pricing methodologies have been developed since the late 80‟s. The earlier approaches were not based on economic principle while the latest are directed to being more based on economic principle as the shift is towards deregulated and privatized electric power industry as opposed to the earlier vertically regulated regime. As a result, many such methodologies based on economic principle have emerged and these reflect the investment cost incurred in circuits and transformers to support real and reactive power flow. However, to reflect investment cost incurred for maintaining network voltages in network charges has received very little attention in network charges. Therefore, this research work is aimed to create a charging approach to recover investment cost, by the network operator, for maintaining the network voltages. This thesis presents a new long-run incremental cost (LRIC) pricing approach for distribution networks and demonstrates the course of action of evaluating and allocating the network asset cost in the context of maintaining network voltages. Also, it should be noted that this approach can be used for transmission networks. Firstly, the LRIC-voltage network pricing approach for reflecting the future network VAr compensation assets is proposed. Then, this approach is extended to consider n-1 contingency situation as per statutory requirement that the network should be able to withstand such contingencies in order to enhance reasonable security and reliability in its network. Lastly, this LRIC-voltage network charging methodology is again extended to reflect the charges for existing network VAr compensation assets. In addition, this LRIC-voltage network pricing approach is improved to reflect better the nodal charges as the respective nodal voltage degradation rates, given corresponding load growth rate, are determined based on the P-V curve concept. The advantages of all these incorporate the ability to reflect correct forward-looking charges, to recognize both real and reactive powers, to provide locational charges and to provide charges for both generation and demand customers. In addition, two fundamental studies were conducted to demonstrate the trend in which the LRIC-voltage network charges would follow given different networks and different load growth rates. What set apart the LRIC-voltage network charges are those two parameters. Moreover, with regard to different networks, this was a defining moment as to how the aforementioned charges should be sought given transmission and distribution networks. A pricing software package utilizing load-flow has been developed implementing the proposed LRIC-voltage network pricing methodology and, its extensions. This software can well be utilized by transmission and distribution companies for analyzing their cost. The LRIC-voltage network pricing methodology and its extensions, are all demonstrated on the IEEE 14-bus test system and a practical distribution test network in the South Wales area of England, UK.
142

Determinantes da performance de longo prazo de IPOs no mercado brasileiro

Navarro Filho, Danilo Mattes January 2016 (has links)
Estudos recentes, realizados principalmente no mercado norte-americano, trazem in-dícios de fatores determinantes para o resultado de longo prazo das emissões primá-rias de ações (IPOs, do inglês Initial Public Offerings). Porém, trabalhos com esse enfoque no mercado brasileiro ainda são escassos e inconclusivos, pois utilizam pe-quenas bases de dados e analisam horizontes de tempo de até dois anos. Buscando ampliar a análise de IPOs no mercado brasileiro, o objetivo desta dissertação foi es-tudar os determinantes do desempenho de longo prazo das IPOs realizadas na Bolsa de Valores de São Paulo com horizontes de tempo de três e cinco anos após o pri-meiro dia de negociações. A amostra foi composta por 97 emissões primárias de ações ocorridas entre 2004 e 2012 para o horizonte de três anos e 77 ocorridas entre 2004 e 2010 para o horizonte de cinco anos. O cálculo de retorno de longo prazo seguiu a metodologia de Buy-and-Hold Abnormal Return (BHAR), ajustado ao Ibo-vespa, e os possíveis determinantes do BHAR das IPOs foram submetidos a análises multivariadas através de estimações pelo método de Mínimos Quadrados Ordinários (MQO). Os resultados levam à conclusão de que o desempenho de longo prazo das IPOs brasileiras está positivamente relacionado com: 1) a Idade das firmas, 2) o nível de Governança Corporativa, 3) o Setor e 4) o Desempenho Operacional pós IPO. Pôde-se concluir, também, que o desempenho de longo prazo das IPOs está negati-vamente relacionado com: 1) o Retorno Anormal do Primeiro Dia de negociações, 2) a Quantidade de IPOs realizadas no Ano e 3) o Percentual de Investidores Institucio-nais na emissão primária. Os testes de robustez realizados apontam para uma relação também positiva entre o Crescimento do PIB do período pré IPO com o resultado de longo prazo das ações. / Recent studies, conducted mainly in the North American market, have presented evi-dence regarding decisive factors for the long-run performance of Initial Public Offerings (IPOs). However, the number of similar studies applied in the Brazilian market is yet limited and inconclusive, because they employ reduced databases and short time win-dows up to two years. Seeking to extend the analysis of IPOs in the Brazilian market, the purpose of this study was to explore the determinants of the long-run performance of IPOs held at BM&F Bovespa, with time windows of three and five years after the first trading day. The sample was composed of 97 initial public offerings occurred be-tween 2004 and 2012 for three-year horizon and 77 occurred between 2004 and 2010 for the five-year horizon. The long-run return calculation followed the methodology of Buy-and-Hold Abnormal Return (BHAR), adjusted to the Ibovespa index, and the pos-sible determinants of BHAR related to IPOs were subjected to multivariate analysis using Ordinary Least Squares (OLS) approach. The results lead to the conclusion that the long-run performance of Brazilian’s IPOs is positively related with: 1) Age of the Firms, 2) the level of Corporate Governance, 3) Sector and 4) post IPO Operating Performance. In addition, it was noticed that the long-run performance of IPOs is neg-atively related with: 1) the Abnormal Return of the First Trading Day, 2) the IPO amount held in the year and 3) percentage of Institutional Investors the IPO. Robustness tests were performed, and their conclusions highlighted a positive relationship between GDP growth of previous IPO period with the long-run performance.
143

Estudo Doppler-ecocardiográfico em atletas de diferentes modalidades esportivas

Moro, André dos Santos [UNESP] 29 May 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-05-29Bitstream added on 2014-06-13T20:41:06Z : No. of bitstreams: 1 moro_as_dr_botfm.pdf: 1409881 bytes, checksum: 8524ea0b5a958d567febf0095de7644c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A expressão ‘‘coração de atleta’’ é normalmente usada para caracterizar os efeitos cardiovasculares do condicionamento físico à longo prazo, em atletas competitivos e altamente treinados. Sabe-se que o exercício físico é um fator estimulante para o desenvolvimento de hipertrofia ventricular esquerda, podendo esta variar de acordo com a característica do esporte. Assim, o coração do atleta apresenta alterações morfológicas e funcionais resultantes de intenso treinamento físico. Embora muitos estudos mostrem alterações cardíacas induzidas pelo exercício, há poucos relatos sobre a adaptação dos ventrículos esquerdo (VE) e direito (VD) em atletas de futebol, ciclismo e corridas de longa distância. Portanto, o objetivo desse estudo foi avaliar por meio da Doppler-ecocardiografia, a estrutura e funções sistólica e diastólica do coração de atletas dessas modalidades esportivas, comparando-as entre si e com indivíduos não-atletas. Neste estudo prospectivo, observacional e transversal, foi realizado ecocardiograma transtorácico, provido da técnica do Doppler tissular, e eletrocardiograma de 12 derivações em repouso em futebolistas profissionais, ciclistas e corredores de longa distância. Foram estudados 57 atletas e 36 indivíduos não-atletas, todos homens, com idades de 32,9±8,4 e 30,4±11,1 anos, respectivamente. As comparações foram realizadas por ANCOVA (idade como covariante) complementada pelo teste de Tukey (p<0,05). As comparações das freqüências de alterações eletrocardiográficas entre os grupos foram realizadas pelo teste de Goodman para contrastes entre populações multinomiais. Os atletas apresentaram aumento do volume do átrio esquerdo, da espessura do VE e dos diâmetros diastólicos do VE (DDVE) e VD (DDVD) em relação aos sedentários. O volume do átrio esquerdo e o DDVE foram maiores nos ciclistas em relação... / The expression “athlete’s heart” is normally used to characterize the cardiovascular effects of physical conditioning in competitive and highly trained athletes. It’s known that physical exercise stimulates the development of left ventricular hypertrophy according to the sports modalities. Thus, the athlete’s heart presents some morphological and functional alterations resultants of the intense physical training. Although many studies have demonstrated cardiac alterations induced by exercise, there are just a few that describe adaptations of left (LV) and right (RV) ventricles in soccer players, bicyclists and long distance runners. Therefore, the objective of this study was to evaluate the structure, systolic and diastolic functions of these athletes by Doppler echocardiography, and compare them among each other and with nonathletes individuals. In this transversal, observational, and prospective study, it was performed a transtoracic ecocardiographic evaluation with tissue Doppler interrogation and a 12-lead electrocardiogram at rest on professional soccer players, bicyclists and long distance runners. Fifty seven athletes and 36 non-athletes men, aged 32.9±8.4 and 30.4±11.1 years, respectively, were studied. Comparisons among the groups were done by ANCOVA (age as co-variate) and complemented by Tukey’s test (p<0.05). Electrocardiographic alterations was analyzed by Goodman’s test for contrasts among multinomial populations. The athletes showed increased left atrial volume, LV wall thickness and enlargement of left (LVDD) and right (RVDD) ventricular diastolic diameters in comparison with non-athletes group. Bicyclists showed larger left atrial volume and LVDD than long distance runners, and also larger RVDD than soccer players. LV mass index was greater in athletes, and the bicyclists showed a greater index than long distance runners and soccer players. Systolic... (Complete abstract click electronic access below)
144

Qualidade da água do escoamento superficial urbano: revisão visando o uso local. / Water quality from initial urban run-off: revision seeking local use.

Maria Carolina Rivoir Vivacqua 15 April 2005 (has links)
O presente trabalho, dissertação visando a obtenção do titulo de mestrado em engenharia na Escola Politécnica da Universidade de São Paulo, é fruto de pesquisa bibliográfica de dados secundários de pesquisa de campo sobre qualidade de águas de chuva após os primeiros escoamentos superficiais. A pesquisa procurou propor e discutir o conceito de uso da água de escoamentos superficiais próximos, como uma das ferramentas para o desenvolvimento e implantação de empreendimentos e programas de gerenciamento de águas. São apresentados e analisados alguns estudos, internacionais selecionados, de qualidade com identificação e quantificação de poluentes de águas provenientes de telhados, pátios e jardins, de ruas e provenientes de áreas maiores como bairros. A análise de resultados das dez pesquisas selecionadas, ao final, possibilitou o conhecimento geral da qualidade de águas da drenagem urbana em seus primeiros momentos. Foi possível, igualmente, identificar usos para essas águas, que revelam-se como mais um manancial de interesse econômico e ambiental, com qualidade. A análise dos estudos permitiu concluir que uso de água de escoamentos superficiais próximos, ou seja água captada em locais próximos a incidência da chuva, é ferramenta básica para o desenvolvimento de empreendimentos que visem a economia de água tratada bem como visem melhorias ambientais. / This work was conducted aiming a master degree in Engeneering in Escola Politécnica of Universidade de São Paulo, and deal with secondary data obtained in field’s researches about rain water quality in the initial run-off. This research intended to propose and to discuss the concept of use of the water from initial run-off, as one of the tools to develop and implant achievement and management programs of waters. It is presented and analyzed some international studies of quality with measure of pollutant components in water obtained from roofs, backyards and gardens, from streets and from bigger areas like several blocks. The date analysis of ten researches selected leads to the improving of the general knowledge of the urban drainage waters quality in its first run-off. This academic work produced, in the same way, the identification of uses for the rain water after first run-off, which was reveled as a source of economic and environmental interest. Analyzing the studies allowed conclude that the use of water after first run-off is basic tool for the development of achievements that seek the economy of treated water as well as environmental improvements.
145

Mapping run-of-river hydropower resource of large catchments

Walker, Antony David January 2018 (has links)
There is overwhelming scientific evidence that shows the temperature of the Earth's atmosphere is rising at an unprecedented rate. This is attributed to increased levels of greenhouse gas emissions, a large proportion of which originates from anthropogenic combustion of carbon-based fossil fuels for energy. There is therefore a strong argument for the increased role of less environmentally damaging, low carbon energy sources including renewable energy technologies. Run-of-river hydropower is one such renewable energy option, considered more environmentally benign than traditional hydropower which requires the construction of large dams to create a reservoir. The aim of this study was to develop a model to search for, and map, economically viable run-of-river hydropower resource that can function on any global catchment of any size. Development and testing of the model was conducted on China's 2 million km2 Yangtze River drainage basin, the third longest river in the world and a rich landscape for hydropower. A gridded, distributed hydrological model was developed integrating high-resolution meteorological datasets and a digital elevation model (DEM). Using the model, the surface hydrology of the Yangtze catchment was simulated at a timestep of 6 minutes to obtain the mean daily surface runoff for every day from the beginning of 1979 to the end of 2007. Observed river flow data from sub-catchments of the Yangtze were used to calibrate the model by differential optimisation, an evolutionary computation technique. Validation was carried out on a 1.6 million km2 sub-catchment resulting in a mean objective function of 0.95 (where a perfect fit would be 1.0) across 8 objective functions commonly used in hydrology. Catchment wide mean daily runoff data was used to develop flow duration curves across the catchment river network. Virtual power stations were constructed at each river cell, iteratively testing differing scheme configurations, and costed using the RETScreen methodology. A best performing hydropower network was determined by a conflict algorithm, designed to prioritise high profit schemes and to remove lower performing and conflicting schemes. This resulted in a potential run-of-river installed capacity across the Yangtze catchment of 103GW (at 10% discount rate), generating 394TWh per annum. This model would be a valuable tool in finding optimal locations for future hydropower resource.
146

Analýza rozložení tlaku na úrovni interakce chodidla a obuvi u běhu po rovině v minimalistické a sportovní obuvi. / Analysis of a pressure distribution on the level of foot and shoe interaction when running in flatlands with minimalist and sport shoes.

Charousek, Jan January 2018 (has links)
Problem: Running is one of the most widespread physical activities. Incorrect running technique, training quantity but also the runner's equipment can strongly affect health condition of the individual, both positively and negatively. For that reason various trends emerge in the area of running footwear. They include classical sports shoes with different types of impact attenuation as well as the minimalist footwear made to imitate barefoot running, which should be much more natural for humans, as insisted by B. Nigg in his book "Born to Run" - where he says that man was born to walk and run barefooted. Inappropriate shoes can cause various health complications, not only in the foot area. Objective: To find out how foot strike changes in the area of the foot-shoe interaction in running on flat ground when an amateur runner uses minimalist and sports footwear and to draw conclusions for training practice on the basis of the results. Methods: The thesis deals with amateur endurance running in different shoe types (minimalist and sports shoes). The study specimen consisted of 14 female runners (mean body weight 63,31 ± 4,89 kg, height 169,69 ± 4,71 cm, age 31,92 ± 5,34 years, speed in minimalist shoes (MO) 3,34 ± 0,06 m.s- 1 , speed in sports shoes (SO) 3,29 ± 0,06 m.s-1 , weekly mileage 37,54 ± 9,43...
147

The Relationships of Physiological and Strength Variables to Run Performances

Hollins, Jana 01 August 2015 (has links)
Monitoring progress of athletes is an essential component of the training process. Collegiate distance running coaches often use field tests to assess progress because of a lack of time and resources to do laboratory testing. The purpose of this dissertation was to examine the relationships between physiological and strength variables measured in a laboratory and field testing measures in collegiate distance runners. Collegiate distance runners completed a series of tests in the Sport Science laboratory at East Tennessee State University to obtain physiological and strength parameters, such as V̇ O2max and vertical jump height. The athletes then completed one of two field tests (either a 3 km time trial or a 3 minute all out run test). There were strong correlations between the laboratory measures and the field test performances. These results indicate that strength is an important factor in run performance. Also, a 3 km time trial and a 3 minute all out run test are suitable for athlete monitoring.
148

Essays in cross-sectional asset pricing

Cederburg, Scott Hogeland 01 May 2011 (has links)
In this dissertation, I study the performance of asset-pricing models in explaining the cross section of expected stock returns. The finance literature has uncovered several potential failings of the Capital Asset Pricing Model (CAPM). I investigate the ability of additional risk factors, which are not considered by the CAPM, to explain these problems. In particular, I examine intertemporal risk and long-run risk in the cross section of returns. In addition, I develop a firm-level test to refine and reassess the cross-sectional evidence against the CAPM. In the first chapter, I test the cross-sectional implications of the Intertemporal CAPM (ICAPM) of Merton (1973) and Campbell (1993, 1996) using a new firm-level approach. I find that the ICAPM performs well in explaining returns. Consistent with theoretical predictions, investors require a large positive premium for taking on market risk and zero-beta assets earn the risk-free rate. Moreover, investors accept lower returns on assets that hedge against adverse shifts in the investment opportunity set. The ICAPM explains more cross-sectional variation in average returns than either the CAPM or Fama-French (1993) model. I also investigate whether the SMB and HML factors of the Fama-French model proxy for intertemporal risk and find little evidence in favor of this conjecture. In the second chapter, we propose an intertemporal asset-pricing model that simultaneously resolves the puzzling negative relations between expected stock return and analysts' forecast dispersion, idiosyncratic volatility, and credit risk. All three effects emerge in a long-run risk economy accommodating a formal cross section of firms characterized by mean-reverting expected dividend growth. Higher cash flow duration firms exhibit higher exposure to economic growth shocks while they are less sensitive to firm-specific news. Such firms command higher risk premiums but exhibit lower measures of idiosyncratic risk. Empirical evidence broadly supports our model's predictions, as higher dispersion, idiosyncratic volatility, and credit risk firms display lower exposure to long-run risk along with higher firm-specific risk. Lastly, in the third chapter, we examine asset-pricing anomalies at the firm level. Portfolio-level tests linking CAPM alphas to a large number of firm characteristics suggest that the CAPM fails across multiple dimensions. There are, however, concerns that underlying firm-level associations may be distorted at the portfolio level. In this paper we use a hierarchical Bayes approach to model conditional firm-level alphas as a function of firm characteristics. Our empirical results indicate that much of the portfolio-based evidence against the CAPM is overstated. Anomalies are primarily confined to small stocks, few characteristics are robustly associated with CAPM alphas out of sample, and most firm characteristics do not contain unique information about abnormal returns.
149

An Analytical Study of the Short-run Variability of Korea's Balance of payments, 1961-85: Application of Keynesian and Monetary Approaches to the Problem

Kim, Dong Yeub 01 May 1989 (has links)
The relationships among the balance of payments and other macroeconomic variables in the Korean economy for the period 1961-85 are analyzed in this study. Theoretical studies on the effects of government policies on the economy and the balance of payments were conducted under both the Keynesian and monetary approaches. The Keynesian approach concentrates on the commodity and capital market adjustment factors and does not focus on the money market factors, whereas the monetary approach considers the balance of payments adjustments as a symptom of money market disequilibrium alone. The basic assumptions of those two approaches, taken seperately, are not fully relevant to the Korean economy, which has unemployed resources, a high proportion of non-traded goods to traded goods, and monetary effects of balance of payments changes. Therefore, a model combining monetary and real factors to explain the short-run behavior of Korea's balance of payments in a single framework is developed. The empirical results of the combined model show that its explanatory power is much higher than either of the two models taken separately. For balance of payments adjustment policy in Korea during the period 1961-85, fiscal and foreign exchange rate policy instruments were found to be very effective in the short-run, but monetary policy instruments were not.
150

Characteristics of Australian edible fungi in the genus Lepista and investigation into factors affecting cultivation

Stott, Karen Gai, University of Western Sydney, Hawkesbury, Faculty of Science and Technology, School of Science, Food and Horticulture January 1998 (has links)
This thesis focuses on the edible fungus Lepista (Pied Bleu or Wood Blewit). Factors affecting its potential commercial cultivation were explored and a contribution to knowledge of the morphology and cultivation of Australian species of Lepista has been made. Australian collections of Lepista were made within a 200 km zone of Sydney. A study of the morphology and taxonomic species of these collections was undertaken. Intra- and inter-fertility crosses were completed with French L. nuda and L. sordida to determine genetic relationships and biological species. Suitable substrates for agar medium, spawn production and cultivation were explored. The response to temperature of French and Australian Lepista in vitro, and Australian Lepista under cultivation, using cold shock, was observed. The effect of modified atmosphere exchanges per hour, CO2 levels, and cold shock during the cultivation cycle and sporophore production were investigated. A genebank of Australian Lepista was established. Three species of Lepista were found in Australia : L. nuda, L. sordida and L. saeva. Two other groups of Lepista were identified. The use of A. bisporus compost appeared to be optimal for experimental and commercial applications. Australian isolates of Lepista tolerate higher temperatures than French isolates, and grew at double the rate of the French at all temperatures except 5 degrees centigrade. The length of the spawn run was reduced from 43-58 days to 12-16 days with introduced CO2 of 9,000-11,000 ppm, but an erratic cyclic pattern of net CO2 production occurred which could only be stabilised by increasing ventilation. This initial cyclic pattern appeared to inhibit subsequent sporophore formation. / Doctor of Philosophy (PhD)

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