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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.
71

Daňová odpisová politika v ČR

Hrachová, Romana January 2007 (has links)
Tématem diplomové práce je daňová odpisová politika v ČR. Jejím cílem je zhodnotit výhody a nevýhody zavedení britského odpisového systému pool do daňové odpisové politiky České republiky. Práce dává stručný a výstižný pohled na daňové a účetní odpisy a objasňuje, zda převzetí britského systému ?pool? je pro naši daňovou odpisovou politiku vhodné, a povede ke zdokonalení systému jako celku. Hlavní část práce spočívá v převzetí základních prvků odpisového systému používaného ve Velké Británii a v nastavení pravidel, za kterých by mohl být pool zaveden do daňové legislativy ČR.
72

REAL-TIME IMAGE PATTERN SENSOR FOR WELD POOL PENETRATION THROUGH REFLECTION IN GTAW

Chen, Yu-Ting 01 January 2018 (has links)
In gas tungsten arc welding (GTAW), weld pool surface contains crucial information for welding development. In this research, simulate skilled welders to control the welding process and determine the penetration stages based on the weld pool reaction. This study focuses on solving the uncertainty of the liquid weld pool in joint bases. The weld pool penetration process is highly depending on how the weld pool surface shape. To observe the weld pool, reflect the weld pool surface by the laser and image on the shield glass. The experiments show that the penetration can’t be determine by the reflecting grayness due to the variability of base metal. To control the joint bases diversity, fed a tip of the wire after the arc is established. Crate the new pattern of the weld pool penetration. Experiments verified the feasibility of this method.
73

A situational analysis of pool car management : the Department of Water Affairs and Forestry, Limpopo Province

Malatji, Masadiki Violet January 2008 (has links)
Thesis (MBA) --University of Limpopo, 2008 / Despite crucial strategic value of fleets, most organizations have relegated the management of their vehicles as being very low on their list of priorities. Consequently, they are entrusting unsuitable people with management of their fleet. Without proper management, huge amounts of money are wasted through fuel fraud and with repairs being done too late or not at all, leaving expensive vehicles idle for months (Barrow 1999).It has been observed that managing fleets with the emphasis on bookkeeping and finance, rather than operational realities, leads to huge and unnecessary costs and massive fraud (Barrow 1998). Efficiency in fleet management is about having a fleet that works directly to support the organizational goals. It is imperative that a study was conducted to analyze the situation of pool cars in the Department of Water Affairs and Forestry (DWAF) in the Limpopo Province to ensure the efficiency in its fleet management
74

Bayesian multivariate predictions

Mao, Weijie 01 December 2010 (has links)
This work offers two strategies to raise the prediction accuracy of Vector Autoregressive (VAR) Models. The first strategy is to improve the Minnesota prior, which is frequently used for Bayesian VAR models. The improvement is achieved in two ways. First, the variance-covariance matrix of regression disturbances is treated as unknown and random to incorporate parameter uncertainty. Second, the prior variance-covariance matrix of regression coefficients is constructed as a function of the variance-covariance matrix of disturbances, in order to account for dependencies between different equations. Since different prior specifications unavoidably lead to different models, and forecasting capability of any such model is often limited, the second strategy is to build an optimal prediction pool of models by using the conventional log predictive score function. The effectiveness of the proposed strategies is examined for one-step-ahead, multi-4-step-ahead, and single-4-step-ahead predictions through two exercises. One exercise is predicting national output, inflation, and interest rate in the United States, and the other is predicting state tax revenue and personal income in Iowa. The empirical results indicate that a properly selected prior can improve the prediction performance of a BVAR model, and that a real-time optimal prediction pool can outperform a single best constituent model alone.
75

Upper Ocean Upwelling, Temperature, and Zonal Momentum Analyses in the Western Equatorail Pacific

Helber, Robert William 14 November 2002 (has links)
The air-sea interaction thermodynamics of the western equatorial Pacific, the Earth's largest region of warm SST, is a major component of the global climate system. Along the equator, warm pool thermodynamics and momentum are influenced by equatorial ocean visco-inertial boundary layer dynamics that occur within a few degrees of the equator because of the sign reversal of the Coriolis force. Designed to study this system, COARE Enhanced Monitoring Array (EMA) observations of temperature, salinity, velocity, and surface meteorology were centered at 0, 156°E from February 1992 through April 1994. They sampled variability on the equator over larger space/time-scales than the concurrent Intensive Flux Array (IFA) centered at 2°S, 156°E. The EMA data are examined within the context of the larger scale equatorial Pacific and the El Niño conditions that occurred at that time. There is a structural change in the equatorial Pacific near the dateline resulting from the winds that are strong, steady, and easterly in the east and generally weak, punctuated by westerly wind bursts, in the west. East of the dateline the EUC's speed and transport increases downstream, while in the west it tends to be zonally uniform, consistent with the extra-tropical ocean interior water pathways that tend to converge on the equator east of the dateline. At 0°, 156°E in the western Pacific deep, seasonal upwelling (appearing stronger after the peak of the 1991/92 El Niño than during the following weaker El Niño year) occurs within the thermocline in boreal summer with magnitudes as large as upwelling in the eastern Pacific cold tongue. This large upwelling is associated with large downward turbulent heat flux and large turbulent shear stress. While the inferred mixing is quantitatively inconclusive because of unresolved potential errors, it is consistent with the visco-inertial boundary layer concepts from early theory [e.g. Arthur 1960; Robinson 1960; Stommel 1960; and Charney and Spiegel 1971]. These findings suggest that the equatorial thermodynamics differ from those of the IFA. Further process experimentation is necessary to quantify these results.
76

Sequestration of metal and metalloid ions by thermophilic bacteria

Hetzer, Adrian January 2007 (has links)
This Ph. D. thesis presents results and conclusions from studies 1) investigating the interaction between metal and metalloid ions and thermophilic bacteria, and 2) characterizing microbial populations in a geothermally active habitat with relatively high concentrations of metalloid ions and compounds. In initial cadmium ion toxicity assays, the minimal inhibition concentration for 46 thermophilic bacteria of the genera Aneurinibacillus, Anoxybacillus, Bacillus, Brevibacillus, Geobacillus, and Thermus were determined. The highest tolerances to cadmium ions (Cd2+) in the range of 400 to 3200 micro;M were observed for species belonging to the genus Geobacillus. The thermophilic Gram-positive bacteria Geobacillus stearothermophilus and G. thermocatenulatus were selected to describe further biosorption reactions between cadmium ions and chemically reactive functional groups (potential ligands) within and onto the bacterial cell walls. Data obtained from electrophoretic mobility, potentiometric titration and cadmium ion adsorption experiments were used to quantify the number and concentrations of ligands and to determine the thermodynamic stability constants for the ligand-cation complexes. The first reported surface complexation models (SCMs) quantifying metal ion adsorption by thermophilic microorganisms predicted cadmium adsorption and desorption by both studied Geobacillus strains over a range of pH values and for different biomasses. The results indicated the functional group, with a deprotonation constant pK value of approximately 3.8, to be more dominant in cation biosorption accounting for 66 and 80% of all titrable groups for G. thermocatenulatus and G. stearothermophilus, respectively. The generated SCMs are different from model parameters obtained from mesophilic species that have been studied to date and might indicate a different biosorption behavior for both studied Geobacillus strains. Another objective of this thesis was to characterize microbial populations in the hot spring Champagne Pool, located in Waiotapu, New Zealand. The thermal spring is approximately 65 m in diameter and discharges water at 75eg; C and pH 5.5, which is oversaturated with arsenic and antimony compounds that precipitate and form orange deposits. Recovered nucleic acids and adenosine 5'-triphosphate (ATP) concentrations obtained for Champagne Pool water samples indicated low microbial density and were in good agreement with relatively low cell numbers of 5.6 plusmn; 0.5 x10^6 cells per ml. Denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene clone library analyses revealed the abundance of Sulfurihydrogenibium, Sulfolobus and Thermofilum-like populations in Champagne Pool. Two novel bacteria and one novel archaeon were successfully isolated with a distant phylogenetic relationship to Sulfurihydrogenibium, Thermoanaerobacter, and Thermococcus, respectively. Genotypic and metabolic characteristics differentiated isolate CP.B2 from described species of the genus Sulfurihydrogenibium. CP.B2 represents a novel genus within the Aquificales order, for which the name Venenivibrio stagnispumantis gen. nov., sp. nov. is proposed. V. stagnispumantis is a thermophilic, chemolithothrophic bacterium, that utilizes molecular hydrogen as electron donor and oxygen as electron acceptor and displayed growth in the presence of up to 8 mM NaAsO2 (As3+) and more than 20 mM Na2HAsO4.7H2O (As5+). However, growth was not observed when Na2HAsO4.7H2O and NaAsO2 were provided as the sole electron acceptor and donor pair. Arsenic resistance was conferred by the genes arsA and arsB
77

Fundamentala faktorers förklaringsgrad och simuleringsmöjligheter gentemot elspotpriset på Nord Pool : Utsläppsrätternas betydelse för elspotpriset under andra handelsperioden

Boström, Martin, Carlsson, Johan January 2010 (has links)
<p>The purpose of this study is to evaluate the relation between certain chosen fundamental factors (emission trading rights, hydrological balance, interaction with continental Europe, fuel prices) and the spot price at Nord Pool. Particular focus has been put on the trade with emission rights since it is only now their actual impact on electricity prices can be studied. The relationships are measured with regression analysis which includes both R<sup>2</sup> and the simulation possibilities of ARX models. The studied period covers 2008 and 2009 with partly daily data and partly weekly data. Owing to the expected higher importance of the fundamentals during the winter months the winter 2008/2009 has been studied separately. The results indicate that there are statistically significant relations between all of the fundamental factors and the spot price save the interaction with continental Europe where Export/Import with Germany which did not yield a significant outcome. The combined R<sup>2</sup> for all fundamental factors was 64 % during the whole period and 83 % during the winter months. In general, the R<sup>2 </sup>was higher during the winter months. The emission trading rights yielded the highest R<sup>2 </sup>during the whole period and the ARX simulation indicate that this factor also has the highest relevance when simulating the spot price during the winter months. However, cross correlation was observed between the price of emission trading rights and the price of natural gas which indicate that these factors contain similar information. Nevertheless, the conclusion that can be drawn is still that the fundamental factors studied are of importance when estimating electricity prices and that the emission trading rights should be taken into account in particular.</p> / <p>Denna undersöknings syfte är att studera sambanden mellan utvalda fundamentala faktorer (handel med utsläppsrätter, hydrologisk balans, interaktion med kontinentala Europa, bränslepriser) och spotpriset på Nord Pool. Fokus har legat på handel med utsläppsrätter då det först nu, i och med den nya handelsperioden 2008-2011, är möjligt att studera utsläppsrätternas faktiska koppling till elpriset. Sambanden undersöks med hjälp av regressionsanalys, vilket omfattar både en studie av förklaringsgrad samt simuleringsmöjligheter med ARX-modeller. Perioden som studeras sträcker sig mellan 2008 och 2009 med delvis dagsdata och veckodata. Vintern 2008/2009 studeras separat på grund av faktorernas förväntade tilltagande betydelse. Resultaten indikerar på att det finns statistiskt säkerställd korrelation mellan samtliga fundamentala faktorer och elspotpriset med undantag för interaktion med kontinental Europa, där export/import med Tyskland inte är signifikant. Den totala förklaringsgraden för samtliga fundamentala faktorer är 64 % under hela perioden och 83 % under vintern. Generellt är förklaringsgraderna högre under vintern än under hela perioden. Handel med utsläppsrätter har klart högst förklaringsgrad av de studerade fundamentala faktorerna under hela perioden och ARX-modelleringen indikerar på att utsläppsrätterna är den faktorn med högst relevans, på 42 % fit, när elsportpriset ska simuleras över vintern. Dock kunde korskorrelation mellan utsläppsrätter och naturgas noteras vilket tyder på att dessa två faktorer ger likartad information. Till skillnad från handel med utsläppsrätter så var de övriga dagsbaserade faktorernas simuleringsmöjligheter låga och ingen direkt analys kunde dras utifrån dessa resultat. Istället lämnas dessa analyser till framtida forskning. Slutsatsen blir att de fundamentala faktorerna, med undantag för import/export med kontinental Europa, är av stor betydelse för elspotpriset där utsläppsrätter bör tas i särskilt beaktande när framtida elspotpriser ska skattas.</p>
78

College Athletics, Undergraduate Recruitment, and Alumni Giving: A Review of the Evidence

Livingston, Ebony Michelle 01 January 2009 (has links)
There has been a long-standing debate about the role and place of intercollegiate athletics (Schulman & Bowen, 2003). Often the focus is on whether successful athletic programs lead to ?value-added? outcomes such as increased alumni giving (Turner, Meserve & Bowen, 2001; Sperber, 2000), or enhanced student applicant pools (Tucker & Amato, 1993; Toma & Cross, 1998; McCormick & Tinsley, 1987; Murphy & Trandel, 1994). The empirical evidence on these issues is both limited, and mixed. For example, the findings of a few methodologically rigorous studies suggest some value-added ?applicant pool? benefits of successful athletic programs. In contrast, studies directly examining student college preferences have produced mixed results. This study offers a review of the extant empirical research on this topic in order to assess the impact of college athletic reputation on three key outcomes: size of applicant pool; quality of applicant pool; and university giving.
79

Fundamentala faktorers förklaringsgrad och simuleringsmöjligheter gentemot elspotpriset på Nord Pool : Utsläppsrätternas betydelse för elspotpriset under andra handelsperioden

Boström, Martin, Carlsson, Johan January 2010 (has links)
The purpose of this study is to evaluate the relation between certain chosen fundamental factors (emission trading rights, hydrological balance, interaction with continental Europe, fuel prices) and the spot price at Nord Pool. Particular focus has been put on the trade with emission rights since it is only now their actual impact on electricity prices can be studied. The relationships are measured with regression analysis which includes both R2 and the simulation possibilities of ARX models. The studied period covers 2008 and 2009 with partly daily data and partly weekly data. Owing to the expected higher importance of the fundamentals during the winter months the winter 2008/2009 has been studied separately. The results indicate that there are statistically significant relations between all of the fundamental factors and the spot price save the interaction with continental Europe where Export/Import with Germany which did not yield a significant outcome. The combined R2 for all fundamental factors was 64 % during the whole period and 83 % during the winter months. In general, the R2 was higher during the winter months. The emission trading rights yielded the highest R2 during the whole period and the ARX simulation indicate that this factor also has the highest relevance when simulating the spot price during the winter months. However, cross correlation was observed between the price of emission trading rights and the price of natural gas which indicate that these factors contain similar information. Nevertheless, the conclusion that can be drawn is still that the fundamental factors studied are of importance when estimating electricity prices and that the emission trading rights should be taken into account in particular. / Denna undersöknings syfte är att studera sambanden mellan utvalda fundamentala faktorer (handel med utsläppsrätter, hydrologisk balans, interaktion med kontinentala Europa, bränslepriser) och spotpriset på Nord Pool. Fokus har legat på handel med utsläppsrätter då det först nu, i och med den nya handelsperioden 2008-2011, är möjligt att studera utsläppsrätternas faktiska koppling till elpriset. Sambanden undersöks med hjälp av regressionsanalys, vilket omfattar både en studie av förklaringsgrad samt simuleringsmöjligheter med ARX-modeller. Perioden som studeras sträcker sig mellan 2008 och 2009 med delvis dagsdata och veckodata. Vintern 2008/2009 studeras separat på grund av faktorernas förväntade tilltagande betydelse. Resultaten indikerar på att det finns statistiskt säkerställd korrelation mellan samtliga fundamentala faktorer och elspotpriset med undantag för interaktion med kontinental Europa, där export/import med Tyskland inte är signifikant. Den totala förklaringsgraden för samtliga fundamentala faktorer är 64 % under hela perioden och 83 % under vintern. Generellt är förklaringsgraderna högre under vintern än under hela perioden. Handel med utsläppsrätter har klart högst förklaringsgrad av de studerade fundamentala faktorerna under hela perioden och ARX-modelleringen indikerar på att utsläppsrätterna är den faktorn med högst relevans, på 42 % fit, när elsportpriset ska simuleras över vintern. Dock kunde korskorrelation mellan utsläppsrätter och naturgas noteras vilket tyder på att dessa två faktorer ger likartad information. Till skillnad från handel med utsläppsrätter så var de övriga dagsbaserade faktorernas simuleringsmöjligheter låga och ingen direkt analys kunde dras utifrån dessa resultat. Istället lämnas dessa analyser till framtida forskning. Slutsatsen blir att de fundamentala faktorerna, med undantag för import/export med kontinental Europa, är av stor betydelse för elspotpriset där utsläppsrätter bör tas i särskilt beaktande när framtida elspotpriser ska skattas.
80

Oil and Gas Production: An Empirical Investigation of the Common Pool

Balthrop, Andrew T 05 May 2012 (has links)
This dissertation focuses on the spatial aspects of oil and natural gas production to investigate the extent and effects of inefficient and unnecessary spatial competition. Because oil and natural gas are migratory, operators can cause hydrocarbon resources to flow from a neighboring property onto his or her own through rapid extraction. This problem is compounded when productive leases are comparatively small, as is the case in Texas. Following an introduction and literature review, the third chapter takes advantage of a natural experiment to demonstrate how spillovers in production limit total cumulative recovery, and how the assignment of secure property rights can enhance economic outcomes. The chapter examines production from wells in Oklahoma and Texas near the panhandle border. While wells on either side of this line have similar geologies and so should be similarly productive they are exposed to different treatments: Oklahoma has a much higher rate of unitization (a contractual scheme where competing owners hire a common operator and share profits), whereas the unitization rate in Texas is lower. Using regression discontinuity design, I find that Oklahoma wells are produced more slowly early on, and that this results in greater cumulative recovery over the course of a well’s life (150% more relative to Texas). These results are robust after controlling for reservoir specific effects, and across parametric, semi-parametric and nonparametric specifications. xiiThe fourth chapter quantifies the degree to which competing owners interfere with each other’s production through spatial spillovers. I use a spatial econometric model that controls for spatial autocorrelation and spatial dependence and can therefore identify the spillovers in production. Additionally, by comparing leases owned by competing producers to leases owned by a common producer, I show empirically how securing property rights through common ownership can alleviate the externality in production. A priori, one would expect that when a common producer owns adjacent leases, the producer has the incentive to fully account for how spillovers in production affect neighboring wells. Conversely, when adjacent landowners are in competition to extract the resource, they will not account for the damage rapid production causes at neighboring wells. After controlling for secondary injection I find that this is indeed the case for Slaughter field of West Texas. The fifth chapter investigates the statistical properties of oil and natural gas production. I find striking evidence that both oil and natural gas production are power-law distributed with the exponent approximately equal to one. This distribution might arise from disequilibrium in production and exploration. Highlighting this distribution is important because it has potential consequences for the political economy of regulation as well as for resource management. For example, because the most productive wells lie in the far-right tail of the distribution, regulation geared to prevent a Deepwater Horizon scale spill need fall on a vanishingly small percent of wells. The distribution also has consequences for management because a company profitability depends disproportionately on how it manages its most productive wells. The sixth chapter provides a short conclusion.

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