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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.
191

A practical introduction to medical statistics

Scally, Andy J. 16 October 2013 (has links)
No / Medical statistics is a vast and ever-growing field of academic endeavour, with direct application to developing the robustness of the evidence base in all areas of medicine. Although the complexity of available statistical techniques has continued to increase, fuelled by the rapid data processing capabilities of even desktop/laptop computers, medical practitioners can go a long way towards creating, critically evaluating and assimilating this evidence with an understanding of just a few key statistical concepts. While the concepts of statistics and ethics are not common bedfellows, it should be emphasised that a statistically flawed study is also an unethical study.[1] This review will outline some of these key concepts and explain how to interpret the output of some commonly used statistical analyses. Examples will be confined to two-group tests on independent samples, using both a continuous and a dichotomous/binary outcome measure.
192

Hedging with the Silver Bullet Fund : A quantitative analysis with AuAg Funds

Beck, Cornelia, Sabic, Nadija January 2024 (has links)
This study examines the hedging effectiveness of the Silver Bullet Fund created by AuAg Funds. The Silver Bullet Fund will be examined alongside a financial proxy and an industry proxy, to assess whether to hedge or not during turbulent times.     The study examines the hedging performance of the Silver Bullet fund by utilizing a static model to capture the behavior of a crisis at a specific point in time, alongside a dynamic model to capture the behavior of crises over time. Further research suggests that several other econometric models can be used for analysis with the same purpose. However, the evidence in this study suggests that a hedged portfolio outperforms an unhedged portfolio during crisis for the S&P500 Index, while for the STOXX 600 Europe Automobiles & Parts Index should not be hedged during the crisis under the static assumption. Moreover, there are also occasions where the standardized returns for the three variables lies outside of the confidence intervals. The study also finds that under the dynamic model, the financial proxy Hedge Ratios during all three crises, compared to the industry proxy, sees the highest value of the Hedge Ratios, however, presenting low hedging effectiveness.
193

Hedge Funds in a Traditional Portfolio : A Quantitative Case Study Made on the Swedish Hedge Fund Market

Sundqvist, Daniel January 2009 (has links)
<p>Hedge funds are a debated subject in today’s financial industry. During 2008, despite hedge funds absolute return target, the global hedge fund industry showed a negative performance whilst the Swedish hedge fund market performed relatively well in comparison. Many studies have been made investigating the effect on incorporating hedge funds in a traditional portfolio though none focused separately on the Swedish market. In a global perspective it is quite easy to invest in hedge fund portfolios due to the existence of investable indices. To invest on the Swedish market is a more complex matter. SIX Harcourt HFXS Index is a Swedish hedge fund index representing the Swedish hedge fund market though it is not investable. Hence it would be interesting to see if it is possible to create an investable version of SIX Harcourt HFXS. When creating an investable index, several administrative costs will arise and in order to cover these costs it would be interesting to see whether or not it possible to optimize SIX Harcourt HFXS Index in purpose of achieving a outperformance which could cover any administrative costs for setting up the investable version. Also, since the optimized version must replicate the standard SIX Harcourt HFXS Index it must maintain a certain level of correlation.</p><p>This thesis, which is based on a positivistic epistemology, is built upon a quantitative case study where SIX Harcourt HFXS Index is optimized in purpose of achieving an outperformance in terms of the risk-adjusted return. The optimization uses an adjusted mean-variance methodology and is limited to a maintained correlation above 0,9 towards the standard SIX Harcourt HFXS Index. The optimization is created through the use of an Excel application created by Harcourt Investment Consulting.</p><p>Also, based on the outperformance by Swedish hedge funds compared to global hedge funds, this study aims to show the effect of incorporating Swedish hedge funds in a traditional portfolio consisting of equities and bonds. This effect is analyzed by the use of several performance-and risk measures.</p><p>The study shows that it is possible to optimize SIX Harcourt HFXS Index and produce an outperformance of approximately 1,5% per annum with a maintained correlation above 0,9. It also shows that the effect of incorporating Swedish hedge funds to a traditional portfolio is positive in regards to both risk and return.</p>
194

Hedge Funds in a Traditional Portfolio : A Quantitative Case Study Made on the Swedish Hedge Fund Market

Sundqvist, Daniel January 2009 (has links)
Hedge funds are a debated subject in today’s financial industry. During 2008, despite hedge funds absolute return target, the global hedge fund industry showed a negative performance whilst the Swedish hedge fund market performed relatively well in comparison. Many studies have been made investigating the effect on incorporating hedge funds in a traditional portfolio though none focused separately on the Swedish market. In a global perspective it is quite easy to invest in hedge fund portfolios due to the existence of investable indices. To invest on the Swedish market is a more complex matter. SIX Harcourt HFXS Index is a Swedish hedge fund index representing the Swedish hedge fund market though it is not investable. Hence it would be interesting to see if it is possible to create an investable version of SIX Harcourt HFXS. When creating an investable index, several administrative costs will arise and in order to cover these costs it would be interesting to see whether or not it possible to optimize SIX Harcourt HFXS Index in purpose of achieving a outperformance which could cover any administrative costs for setting up the investable version. Also, since the optimized version must replicate the standard SIX Harcourt HFXS Index it must maintain a certain level of correlation. This thesis, which is based on a positivistic epistemology, is built upon a quantitative case study where SIX Harcourt HFXS Index is optimized in purpose of achieving an outperformance in terms of the risk-adjusted return. The optimization uses an adjusted mean-variance methodology and is limited to a maintained correlation above 0,9 towards the standard SIX Harcourt HFXS Index. The optimization is created through the use of an Excel application created by Harcourt Investment Consulting. Also, based on the outperformance by Swedish hedge funds compared to global hedge funds, this study aims to show the effect of incorporating Swedish hedge funds in a traditional portfolio consisting of equities and bonds. This effect is analyzed by the use of several performance-and risk measures. The study shows that it is possible to optimize SIX Harcourt HFXS Index and produce an outperformance of approximately 1,5% per annum with a maintained correlation above 0,9. It also shows that the effect of incorporating Swedish hedge funds to a traditional portfolio is positive in regards to both risk and return.
195

Performance Analysis of Diversity Techniques for Wireless Communication System

ISLAM, MD. JAHERUL January 2012 (has links)
Different diversity techniques such as Maximal-Ratio Combining (MRC), Equal-Gain Combining (EGC) and Selection Combining (SC) are described and analyzed. Two branches (N=2) diversity systems that are used for pre-detection combining have been investigated and computed. The statistics of carrier to noise ratio (CNR) and carrier to interference ratio (CIR) without diversity assuming Rayleigh fading model have been examined and then measured for diversity systems. The probability of error (p_e) vs CNR and (p_e) versus CIR have also been obtained. The fading dynamic range of the instantaneous CNR and CIR is reduced remarkably when diversity systems are used [1]. For a certain average probability of error, a higher valued average CNR and CIR is in need for non-diversity systems [1]. But a smaller valued of CNR and CIR are compared to diversity systems. The overall conclusion is that maximal-ratio combining (MRC) achieves the best performance improvement compared to other combining methods. Diversity techniques are very useful to improve the performance of high speed wireless channel to transmit data and information. The problems which considered in this thesis are not new but I have tried to organize, prove and analyze in new ways.
196

Parâmetros de controle da resistência mecânica de solos tratados com cal, cimento e rocha basáltica pulverizada / Key parameters for strength control of soils treated with lime, cement and pulverized basaltic rock

Lopes Júnior, Luizmar da Silva January 2007 (has links)
Cada vez mais freqüente a utilização de técnicas tradicionais da engenharia geotécnica depara-se com obstáculos de caráter econômico e ambiental. A técnica do solo-cal torna-se atrativa quando o melhoramento das propriedades do solo do local constitui-se numa alternativa de projeto. A técnica de tratamento de solos com cal encontra aplicação, por exemplo, na construção de bases para pavimentos, na proteção de taludes em barragens de terra e como camada de suporte para fundações superficiais. Entretanto, ainda não existem metodologias de dosagem e projeto das misturas de solo-cal baseadas em critérios racionais como existe no caso do concreto, onde a relação água/cimento desempenha papel fundamental na obtenção da resistência desejada. Nesse sentido, este estudo tem por objetivo quantificar a influência da quantidade de cal, da porosidade e do teor de umidade de moldagem, sobre a resistência de um solo arenoso tratado com cal e rocha basáltica pulverizada, avaliar a adequação do uso das relações água/cal e vazios/cal na estimativa da sua resistência à compressão simples e comparar as variáveis envolvidas com amostras tratadas com cimento em iguais proporções. Para isso foram realizados ensaios de compressão simples e medidas de sucção matricial. Os resultados mostram que a resistência à compressão simples cresceu linearmente com o aumento da quantidade de cal e exponencialmente com a redução na porosidade da mistura compactada. Além disso, a variação do teor de umidade de moldagem não afetou consideravelmente a resistência à compressão simples em misturas compactadas numa mesma massa específica aparente seca. Verificou-se que, para o solo-cal no estado nãosaturado (estado em que normalmente se encontram os aterros compactados), a relação água/cal não é um bom parâmetro para estimativa da resistência à compressão simples. Ao contrário, a relação vazios/cal, assim como a relação vazios/cimento, definido pela razão entre a porosidade da mistura compactada e o teor volumétrico de aglomerante, ajustado por um expoente, demonstraram ser o parâmetro mais adequado na estimativa da resistência à compressão simples do solo-cal e do solo-cimento estudado. / Not rarely, the use of traditional techniques in geotechnical engineering faces obstacles of economical and environmental nature. The soil-lime technique becomes attractive when the improvement of the local soil is a project alternative. The treatment of soils with lime finds application, for instance, in the construction of pavement base layers, in slope protection of earth dams and as a support layer for shallow foundations. However, there are no dosage methodologies and design based on rational criteria as it exists in the case of concrete technology, where the water/cement ratio plays a fundamental role in the assessment of the target strength. In that sense, this study aims to quantify the influence of lime amount, the porosity and the moisture content on the strength of a sandy soil treated with lime and pulverized basaltic rock, as well as to evaluate the use of a water/lime ratio and a voids/lime ratio to assess its unconfined compression strength and to compare the evaluated variables with samples treated by cement in the same proportions. A number of unconfined compression tests and measures of matric suction were carried out. The results show that the unconfined compression strength increased linearly with the increase of the lime amount and exponentially with the reduction on the porosity of the compacted mixture. Besides, the change on the moisture content doesn’t remarkably affected the unconfined compression strength of mixtures compacted in the same dry density. It was verified that, for the soil-lime in the unsaturated state (state usually met in compacted fills), the water/lime ratio is not a good parameter for assessment of unconfined compression strength. In the other hand, the voids/lime ratio, as well as the voids/cement ratio, defined by the reason between the porosity of the compacted mixture and the volumetric binder content, adjusted by an exponent, demonstrated to be the most appropriate parameter in the estimate of unconfined compression strength of the studied soil-lime and soil-cement.
197

Parâmetros de controle da resistência mecânica de solos tratados com cal, cimento e rocha basáltica pulverizada / Key parameters for strength control of soils treated with lime, cement and pulverized basaltic rock

Lopes Júnior, Luizmar da Silva January 2007 (has links)
Cada vez mais freqüente a utilização de técnicas tradicionais da engenharia geotécnica depara-se com obstáculos de caráter econômico e ambiental. A técnica do solo-cal torna-se atrativa quando o melhoramento das propriedades do solo do local constitui-se numa alternativa de projeto. A técnica de tratamento de solos com cal encontra aplicação, por exemplo, na construção de bases para pavimentos, na proteção de taludes em barragens de terra e como camada de suporte para fundações superficiais. Entretanto, ainda não existem metodologias de dosagem e projeto das misturas de solo-cal baseadas em critérios racionais como existe no caso do concreto, onde a relação água/cimento desempenha papel fundamental na obtenção da resistência desejada. Nesse sentido, este estudo tem por objetivo quantificar a influência da quantidade de cal, da porosidade e do teor de umidade de moldagem, sobre a resistência de um solo arenoso tratado com cal e rocha basáltica pulverizada, avaliar a adequação do uso das relações água/cal e vazios/cal na estimativa da sua resistência à compressão simples e comparar as variáveis envolvidas com amostras tratadas com cimento em iguais proporções. Para isso foram realizados ensaios de compressão simples e medidas de sucção matricial. Os resultados mostram que a resistência à compressão simples cresceu linearmente com o aumento da quantidade de cal e exponencialmente com a redução na porosidade da mistura compactada. Além disso, a variação do teor de umidade de moldagem não afetou consideravelmente a resistência à compressão simples em misturas compactadas numa mesma massa específica aparente seca. Verificou-se que, para o solo-cal no estado nãosaturado (estado em que normalmente se encontram os aterros compactados), a relação água/cal não é um bom parâmetro para estimativa da resistência à compressão simples. Ao contrário, a relação vazios/cal, assim como a relação vazios/cimento, definido pela razão entre a porosidade da mistura compactada e o teor volumétrico de aglomerante, ajustado por um expoente, demonstraram ser o parâmetro mais adequado na estimativa da resistência à compressão simples do solo-cal e do solo-cimento estudado. / Not rarely, the use of traditional techniques in geotechnical engineering faces obstacles of economical and environmental nature. The soil-lime technique becomes attractive when the improvement of the local soil is a project alternative. The treatment of soils with lime finds application, for instance, in the construction of pavement base layers, in slope protection of earth dams and as a support layer for shallow foundations. However, there are no dosage methodologies and design based on rational criteria as it exists in the case of concrete technology, where the water/cement ratio plays a fundamental role in the assessment of the target strength. In that sense, this study aims to quantify the influence of lime amount, the porosity and the moisture content on the strength of a sandy soil treated with lime and pulverized basaltic rock, as well as to evaluate the use of a water/lime ratio and a voids/lime ratio to assess its unconfined compression strength and to compare the evaluated variables with samples treated by cement in the same proportions. A number of unconfined compression tests and measures of matric suction were carried out. The results show that the unconfined compression strength increased linearly with the increase of the lime amount and exponentially with the reduction on the porosity of the compacted mixture. Besides, the change on the moisture content doesn’t remarkably affected the unconfined compression strength of mixtures compacted in the same dry density. It was verified that, for the soil-lime in the unsaturated state (state usually met in compacted fills), the water/lime ratio is not a good parameter for assessment of unconfined compression strength. In the other hand, the voids/lime ratio, as well as the voids/cement ratio, defined by the reason between the porosity of the compacted mixture and the volumetric binder content, adjusted by an exponent, demonstrated to be the most appropriate parameter in the estimate of unconfined compression strength of the studied soil-lime and soil-cement.
198

Parâmetros de controle da resistência mecânica de solos tratados com cal, cimento e rocha basáltica pulverizada / Key parameters for strength control of soils treated with lime, cement and pulverized basaltic rock

Lopes Júnior, Luizmar da Silva January 2007 (has links)
Cada vez mais freqüente a utilização de técnicas tradicionais da engenharia geotécnica depara-se com obstáculos de caráter econômico e ambiental. A técnica do solo-cal torna-se atrativa quando o melhoramento das propriedades do solo do local constitui-se numa alternativa de projeto. A técnica de tratamento de solos com cal encontra aplicação, por exemplo, na construção de bases para pavimentos, na proteção de taludes em barragens de terra e como camada de suporte para fundações superficiais. Entretanto, ainda não existem metodologias de dosagem e projeto das misturas de solo-cal baseadas em critérios racionais como existe no caso do concreto, onde a relação água/cimento desempenha papel fundamental na obtenção da resistência desejada. Nesse sentido, este estudo tem por objetivo quantificar a influência da quantidade de cal, da porosidade e do teor de umidade de moldagem, sobre a resistência de um solo arenoso tratado com cal e rocha basáltica pulverizada, avaliar a adequação do uso das relações água/cal e vazios/cal na estimativa da sua resistência à compressão simples e comparar as variáveis envolvidas com amostras tratadas com cimento em iguais proporções. Para isso foram realizados ensaios de compressão simples e medidas de sucção matricial. Os resultados mostram que a resistência à compressão simples cresceu linearmente com o aumento da quantidade de cal e exponencialmente com a redução na porosidade da mistura compactada. Além disso, a variação do teor de umidade de moldagem não afetou consideravelmente a resistência à compressão simples em misturas compactadas numa mesma massa específica aparente seca. Verificou-se que, para o solo-cal no estado nãosaturado (estado em que normalmente se encontram os aterros compactados), a relação água/cal não é um bom parâmetro para estimativa da resistência à compressão simples. Ao contrário, a relação vazios/cal, assim como a relação vazios/cimento, definido pela razão entre a porosidade da mistura compactada e o teor volumétrico de aglomerante, ajustado por um expoente, demonstraram ser o parâmetro mais adequado na estimativa da resistência à compressão simples do solo-cal e do solo-cimento estudado. / Not rarely, the use of traditional techniques in geotechnical engineering faces obstacles of economical and environmental nature. The soil-lime technique becomes attractive when the improvement of the local soil is a project alternative. The treatment of soils with lime finds application, for instance, in the construction of pavement base layers, in slope protection of earth dams and as a support layer for shallow foundations. However, there are no dosage methodologies and design based on rational criteria as it exists in the case of concrete technology, where the water/cement ratio plays a fundamental role in the assessment of the target strength. In that sense, this study aims to quantify the influence of lime amount, the porosity and the moisture content on the strength of a sandy soil treated with lime and pulverized basaltic rock, as well as to evaluate the use of a water/lime ratio and a voids/lime ratio to assess its unconfined compression strength and to compare the evaluated variables with samples treated by cement in the same proportions. A number of unconfined compression tests and measures of matric suction were carried out. The results show that the unconfined compression strength increased linearly with the increase of the lime amount and exponentially with the reduction on the porosity of the compacted mixture. Besides, the change on the moisture content doesn’t remarkably affected the unconfined compression strength of mixtures compacted in the same dry density. It was verified that, for the soil-lime in the unsaturated state (state usually met in compacted fills), the water/lime ratio is not a good parameter for assessment of unconfined compression strength. In the other hand, the voids/lime ratio, as well as the voids/cement ratio, defined by the reason between the porosity of the compacted mixture and the volumetric binder content, adjusted by an exponent, demonstrated to be the most appropriate parameter in the estimate of unconfined compression strength of the studied soil-lime and soil-cement.
199

Chlapec nebo dívka / BABY BOY OR BABY GIRL

Zákostelná, Lucie January 2013 (has links)
The thesis is mainly focused on the analysis and evaluation of the effects influencing the sex ratio of live births. After studying of the foreign language literature, main factors influencing the sex ratio are defined. Data used in the thesis (births by the sex) are retrieved from The Human Mortality Database, database of United Nations Statistics Division and from particular statistical offices. Based on the results of the exploratory data analysis, countries with unreliable data (data skewed due to the manipulation or due to the not appropriate standard of the registration of born) are specified. Subsequently, the countries with abnormal values of the sex ratio at birth resulting from the cultural traditions or technological development are defined. For countries with not evident influence of the factors mentioned the analysis of the relations and dependencies between sex ratio at birth and variables chosen (groups of the geographical, socioeconomics and demographical impacts). On the basis of this analysis it has been proved that the sex ratio at birth depends primarily, but not exclusively, on the total fertility rate and life expectancy.
200

Hodnocení finanční situace podniku a návrhy na její zlepšení / Evaluation of the Financial Situation in the Firm and Proposals to its Improvement

Bačíková, Michaela January 2011 (has links)
The diploma thesis focuses on determine the financial health selected company in years 2005 – 2009. Methods of marketing situational analysis and methods of financial analysis are used in the diploma thesis. Based on the results of this analysis are made suggestions to improve the financial situation of the company.

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