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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.
271

Akutní vliv statického a dynamického strečinku na výskok / Acute effect of static and dynamic stretching on vertical jump

Dostálová, Anna January 2017 (has links)
Title Acute effect of static and dynamic stretching on vertical jump. Objectives The aim of this thesis is to assess whether it is better to warm up by static or dynamic stretching in order to improve performance in the vertical jump. Methods The first part of this thesis is theoretical and is the basis for measurement, which is described in the second part. The tested set consists of ten women volleyball players. Each player underwent three vertical jump measurements on power plates Kistler, which recorded flight time of the player over the plates. All measurements were evaluated afterwards. Five attempts were recorded in each measurement. Measurements were carried out without stretching, after dynamic stretching and after static stretching. The thesis includes a survey that monitors the perception of the players` performance. Results Results of the total tested set measurement show that inclusion of dynamic stretching during the warm up leads to a slight decline in the physical performance. This decrease presents about 0.92%. Another conclusion of this research is that the inclusion of static stretching to the warm up also results in a slight decrease in the athletic performance. In this case the decrease is about 1.72%. In a direct comparison of these two types of stretching, the inclusion of...
272

Instant Feedback Loops – for short feedback loops and early quality assurance

Mehraban, Mehrdad January 2016 (has links)
Context. In recent years, Software Quality Assurance (SQA) has become a crucial part of software development processes. Therefore, modern software development processes led to an increase in demand for manual and automated code quality assurance. Manual code quality reviews can be a time-consuming and expensive process with varying results. Thus, automated code reviews turn out to be a preferred alternative for mitigating this process. However, commercial and open-source static code analyzer tools often offer deep analysis with long lead time. Objectives. In this thesis work, the main aim is to introduce an early code quality assurance tool, which features a combination of software metrics. The tool should be able to examine code quality and complexity of a telecommunication grade software product such as source code of specific Ericsson product by Ericsson. This tool should encapsulate complexity and quality of a software product with regards to its efficiency, scope, flexibility, and execution time. Methods. For this purpose, the background section of the thesis is dedicated to in-depth research on software metrics included in well-known static code analyzers. Then, development environment, under investigation source code of Ericsson product, and collected software metric for evaluation were presented. Next, according to each software metric’s characteristics, point of interest, and requirement, a set of steps based on a Susman’s action research cycle were defined. Moreover, SWAT, a suitable software analytics toolkit, employed to extract conducted experiment data of each software metric from a static analyzer code named Lizard in order to detect most efficient software metrics. Outcome of conducted experiment demonstrates relationship of selected software metrics with one another. Results. The chosen software metrics were evaluated based on a variety of vital factors especially actual data from number of defects of specific Ericsson product. Highly effective software metrics from investigations in this thesis work were implemented as a new model named hybrid model to be utilized as an early quality assurance. Conclusions. The proposed model, which consist of well-performing software metrics, demonstrate an impressive performance as an early code quality indicator. Consequently, the utilized model in this master thesis could be studied in a future research to further investigate the effectiveness and robustness of this tool an early quality assurance.
273

An Analytic Image-Technology Inventory of National Tourism Organizations (NTOs)

Chang, Lung-chiuan 15 December 2006 (has links)
The Internet is playing an increasingly crucial role in destination marketing and it is used as a major marketing tool among National Tourism Organizations (NTOs). Website design is influential for consumers' Website preference and destination selection. This study is to understand the application of image-based technology by the major National Tourism Organizations (NTOs) through the collection and comparison of static images and dynamic images presented in their official tourism Websites. Data collected from the sampling of the world's top 25 tourism destination nations reveals that all National Tourism Organizations (NTOs) use either static images or dynamic images for their Websites, but the use of static images are far more popular than that of dynamic images.
274

Comparative Analysis of Load Flow Techniques for Steady State Loading Margin and Voltage Stability Improvement of Power Systems

Togiti, Santosh 11 August 2015 (has links)
Installation of reactive compensators is widely used for improving power system voltage stability. Reactive compensation also improves the system loading margin resulting in more stable and reliable operation. The improvements in system performance are highly dependent on the location where the reactive compensation is placed in the system. This paper compares three load flow analysis methods - PV curve analysis, QV sensitivity analysis, and Continuation Load Flow - in identifying system weak buses for placing reactive compensation. The methods are applied to three IEEE test systems, including modified IEEE 14-bus system, IEEE 30-bus system, and IEEE 57-bus system. Locations of reactive compensation and corresponding improvements in loading margin and voltages in each test system obtained by the three methods are compared. The author also analyzes the test systems to locate the optimal placement of reactive compensation that yields the maximum loading margin. The results when compared with brute force placement of reactive compensation show the relationship between effectiveness of the three methods and topology of the test systems.
275

Static Friction in Slip Critical Bolt Joints : Coefficient of Friction in Steel, Aluminium and ED Coated Steel

Lång, Marcus January 2017 (has links)
This project was performed together with ÅF Industry AB in Trollhättan, Sweden. ÅF’s expertise in Trollhättan is oriented towards the automotive industry. It was conducted within the section of CAE and safety where they, for instance, dimension bolt joints in the cars. Bolt joints play an important role in the automotive industry. Slip critical bolt joints are used widely throughout the vehicles. With lack of good test data, the bolt joints need to be dimensioned conservatively. This may lead to that bolt joints are over-dimensioned, adding more mass to the car. On the contrary, the availability of reliable test data enables designers to optimize joint dimensions to achieve a safe design with minimized mass. A mechanical testing configuration has been designed as well as a testing procedure for a test to determine the static friction value between mating surfaces in bolt joints. The testing configuration has been used to perform tests to find the static friction coefficient in different materials. The study contains varied combinations of steel, aluminium and ED-Coated steel. The study resulted in tables with levels of probability. The developed test configuration is robust and relatively simple to use and is recommended for further use. For improved statistical significance, it was noted that more samples should be used than was used in this study. The aluminium has a smoother surface finish and that could be the reason why its coefficient of friction is lower than steel. It is therefore considered important to also include surface roughness when presenting coefficient of friction results.
276

Demand-Driven Static Analysis of Heap-Manipulating Programs

Chenguang Sun (5930306) 16 August 2019 (has links)
<div>Modern Java application frameworks present significant challenges for existing static analysis algorithms. Such challenges include large-scale code bases, heap-carried dependency, and asynchronous control flow caused by message passing.</div><div>Existing analysis algorithms are not suitable to deal with these challenges. One reason is that analyses are typically designed to operate homogeneously on the whole program. This leads to scalability problems when the analysis algorithms are used on applications built as plug-ins of large frameworks, since the framework code is analyzed together with the application code. Moreover, the asynchronous message passing of the actor model adopted by most modern frameworks leads to control flows which are not modeled by existing analyses.</div><div>This thesis presents several techniques for more powerful debugging and program understanding tools based on slicing. In general, slicing-based techniques aim to discover interesting properties of a large program by only reasoning about the relevant part of the program (typically a small amount of code) precisely, abstracting away the behavior of the rest of the program.</div><div>The key contribution of this thesis is a demand-driven framework to enable precise and scalable analyses on programs built on large frameworks. A slicing algorithm, which can handle heap-carried dependence, is used to identify the program elements relevant to an analysis query. We instantiated the framework to infer correlations between registration call sites and callback methods, and resolve asynchronous control flows caused by asynchronous message passing.</div>
277

Static or Dynamic Efficiency: Horizontal Merger Effects in the Wireless Telecommunications Industry

Grajek, M., Gugler, Klaus, Kretschmer, T., Miscisin, I. January 2019 (has links) (PDF)
This paper studies five mergers in the European wireless telecommunication industry and analyzes their impact on prices and capital expenditures of both merging carriers and their rivals. We find substantial heterogeneity in the relationship between increases in concentration and carriers' prices. The specifics of each merger case clearly matter. Moreover, we find a positive correlation between the price and the investment effect; when the prices after a merger increase (decrease), the investments increase (decrease) too. Thus, we document a trade-off between static and dynamic efficiency of mergers.
278

Étude de l'élaboration en continu d'émulsions de bitime [i.e.bitume] à taille de gouttes maîtrisée à l'aide de mélangeurs statiques / Study of continuous process using static mixers for the production of bitumen emulsions with controlled droplet size

Arenas Calderon, Edward Julián 18 June 2014 (has links)
Cette étude porte sur l'émulsification en continu du bitume à l'aide de mélangeurs statiques de type SMX, dans le domaine des émulsions concentrées, voire très concentrées. Ce travail suit une approche intégrant trois types de paramètres : procédé, formulation physico-chimique et composition, avec pour objectif ultime la maîtrise de la taille de gouttes. Il a été montré qu'une combinaison de fortes teneurs en bitume et de hautes températures d'émulsification favorisent l'obtention de très petites tailles de gouttes (diamètre médian inférieur ou égal à 1 µm). Cette observation contraste avec l'émulsification à forte teneur en phase dispersée en procédé discontinu. Ces résultats mettent en évidence une compétition entre les aspects énergétiques de l'émulsification et la formulation physico-chimique. Il a été mis en évidence, que lors de l'émulsification en continu à des fractions massiques en bitume supérieures à 90 %, la taille des gouttes n'est pas une fonction de l'énergie fournie mais que ce sont les paramètres de formulation qui contrôlent l'émulsification. Le suivi de la cinétique de l'émulsification et de la morphologie de l'émulsion au cours du processus d'émulsification a montré que le mécanisme d'émulsification à très fortes concentrations en bitume (90 % massique) passe par une étape d'inversion de phases catastrophique, suivie d'un affinage de l'émulsion dû aux effets de cisaillement et d'élongation lors de la phase finale de mélange. Une méthodologie basée sur une analogie de Poiseulle pour la mesure en ligne de la viscosité de procédé a été développée, permettant l'évaluation in-line du comportement rhéologique d'un fluide à travers des mesures de débit et de perte de charge / This work focuses on the continuous emulsification process (using SMX static mixers) of bitumen for concentrated and highly concentrated emulsions. This work uses an approach that integrates the process, the physic-chemical formulation and composition parameters, with the main objective of controlling the drop size of the emulsions. It was shown that the emulsification carried out at high bitumen concentrations and high temperatures favours the production of emulsions with very small droplets sizes (mean diameter ? 1 mm). This is in contrast with emulsification process in batch mode, in the same concentration and temperature conditions. These results demonstrate the competition between energy and physic-chemical formulation aspects. It was also revealed that when continuous emulsification is carried out at 90 % wt. of bitumen, droplet sizes are not a function of the energy provided and, hence, the emulsification process is controlled by the formulation parameters. Morphological analyzes, coupled with kinetics of emulsification obtained by in-situ monitoring of the viscosity, allowed the description of the mechanisms occurring during the emulsification at high internal phase ratio. It was possible to identify two principal steps in the mechanism: a catastrophic phase inversion followed by a droplet reduction by agitation, the largest size reduction being achieved thanks to the effects of shear and elongation in the static mixer. An inline process viscosity measurement methodology was developed. This methodology, based on a Poiseuille analogy, allows the evaluation of the rheological behavior of a fluid through flow rate and pressure drop measurements
279

Avaliação da superfície deformada de geomembrana de PEAD sob camadas de proteção por meio do ensaio de compressão estática / Evaluation of the deformed surface of PEAD geomembrane in protective layers by means of the static compression test

Pedroso, Gabriel Orquizas Mattielo 12 April 2017 (has links)
Nos sistemas de revestimento de fundo de aterros sanitários e pilhas de rejeito de mineração, é comum utilizar geotêxtil não-tecido para a proteção ao puncionamento da geomembrana por objetos pontiagudos como a brita. Neste trabalho, realiza-se um estudo experimental a fim de avaliar a superfície deformada de geomembrana de PEAD, com 2 mm de espessura, em camada de proteção sujeita a carregamentos de 600 kPa e 1800 kPa ao longo de 100 h, com o objetivo de simular danos mecânico de operação. Para a leitura da superfície deformada da geomembrana utilizou-se um lençol de chumbo localizado sob a geomembrana e as suas deformações foram estimadas a partir de uma máquina de leitura por coordenadas, com grid de 4 mm. Além deste, foi estimada a superfície deformada da geomembrana para o grid de 1 mm, com a aplicação do método de interpolação chamado de triangulação. Ainda foram utilizados extensômetros elétricos para estimar deformações pontuais na geomembrana. A fim de prevenir o puncionamento da geomembrana e limitar a sua deformação, utilizou-se como camada de proteção quatro geotêxteis não tecidos do tipo PP com massa por unidade de área variando entre 550 e 1300 g/m2, e uma camada de 10 cm de argila. Para a carga de 600 kPa, todas as camadas de proteção foram eficientes para evitar o puncionamento da geomembrana e limitar a sua deformação em 6%. Na carga de 1800 kPa, para proteção de geotêxtil, as configurações duplas tiveram melhor desempenho com valores de deformações menores que 6%, e a camada de 10 cm de argila foi ainda mais eficaz. Por fim, o trabalho mostrou que a superfície deformada decorrente do tipo de proteção adotado também é influenciada pelo grau de compactação do solo, o tipo de brita, a carga aplicada e as propriedades físicas do elemento de proteção. / In landfill backfill systems and mining tailings piles, it is common to use nonwoven geotextiles to protect geomembrane punctures by sharp objects such as gravel. In this work, an experimental study was carried out to evaluate the deformed HDPE geomembrane surface, with a thickness of 2 mm, under a protective layer subjected to loads of 600 kPa and 1800 kPa over 100 h, with the objective of Simulate mechanical damage of operation. To read the deformed surface of the geomembrane was used a sheet of lead located under the geomembrane and its deformations were estimated from a machine of reading by coordinates, with grid of 4 mm. Also, the deformed surface of the geomembrane was estimated for the grid of 1 mm, with the application of the interpolation method called triangulation. Electrical extensometers were also used to estimate point deformations in the geomembrane. In order to prevent the puncture of the geomembrane and to limit its deformation, four non-woven PP-type geotextiles with a mass per unit area ranging from 550 to 1300 g/m2 and a layer of 10 cm of clay. At the load of 600 kPa, all the layers of protection were efficient to avoid the puncture of the geomembrane and to limit its deformation in 6%. In the vertical load of 1800 kPa, for geotextile protection, the double configurations had better performance with deformation values lower than 6%, and the 10 cm layer of clay was even more effective. Finally, the work showed that the deformed surface resulting from the type of protection adopted is also influenced by the degree of soil compaction, the type of gravel, the applied load and the physical properties of the protection element.
280

Análise de comportamento de estaca barrete embutida em rocha. / Behavior analysis of a rock socket barrette pile.

Musarra, Marcello Duarte 01 September 2014 (has links)
Para proporcionar menores prazos e custos, o projeto de ampliação da sede da Petrobras, na cidade de Salvador, estado da Bahia, contemplou estacas barretes de grandes dimensões para grandes capacidades de carga. Porém, para atingir as cargas escolhidas, foi necessário embutir as estacas no topo rochoso. Portanto, foram projetadas estacas barretes embutidas em rocha, escavadas com hidrofresa. Esta pesquisa apresenta o estudo de duas provas de carga estáticas executadas em uma mesma estaca barrete teste embutida em rocha, a fim de proporcionar um melhor entendimento de seu comportamento, assim como os principais fatores que influenciam resistência e deformabilidade. Em março de 2012, foram realizadas duas provas de carga estáticas na mesma estaca barrete teste embutida em rocha. Os ensaios foram executados a partir das metodologias normativas NBR 12131 (2006) e NBR 6122 (2010), com carregamentos lento e rápido, respectivamente e subsequentemente. No primeiro ensaio (lento), aplicou-se a carga máxima de 12 MN, enquanto que no segundo (rápido), aplicou-se a carga máxima de 14 MN. Os dados obtidos nos ensaios, de acordo com a bibliografia utilizada, são pioneiros no Brasil, por se tratar da primeira estaca barrete embutida em rocha com utilização de hidrofresa, submetida à prova de carga de desempenho. A estaca foi instrumentada em profundidade, o que propiciou a avaliação da distribuição de carga nas camadas atravessadas. Foram realizadas comparações entre resultados obtidos da instrumentação e do topo, por meio do repique elástico. Além da avaliação e interpretação dos dados obtidos nos ensaios de provas de carga estáticas, esta pesquisa apresenta previsões de comportamento, com diferentes conceitos, para estacas embutidas em rocha, sem reação de ponta, com intuito de comparar seus resultados com os obtidos nos ensaios. Em conjunto com as previsões, foram apresentados métodos para estimativa de adesão lateral na interface da estaca com o maciço rochoso. / To use high loads on foundations of the Petobras Headquarters, the designers chose the barrette pile with great dimensions and a few units compared with others types, to shorten the deadline and optimize costs. However, to reach these assumptions, it was necessary make the piles deeper than the soil strata, and, therefore, made a rock socket design. This research presents two static load tests study and analysis in the same barrette test pile, to forecast behavior and find resistance and strain influences. In March, 2012, two static load tests were made in the same barrette test pile located in Salvador Bahia, in Petrobras headquarters. The first essay was made according to a slow maintained test with 12 MN maximum compressive loads. The second essay was made immediately after, according to a quick load test and 14 MN maximum compressive loads. The data obtained from both tests, far as is known, were the first results on rock socket barrette pile in Brazil, using hydromill for the excavations in rock. The pile had depth instrumentation with expansible strain gages and an expanded polystyrene block below the cage, to make the tip useless. Beyond the data assessment and interpretation from static load tests, this research presents forecasting methods to only shear resistance rock socket piles, with the aim of comparison. Lastly but not least, side resistance empirical methods between pile and rock interface were presented.

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