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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.
101

Universalus pertvarkų įrankis / Universal refactoring tool

Peldžius, Stasys 25 November 2010 (has links)
Vykstant nuolatiniam programų sistemų atnaujinimui, nuolatos reikia prižiūrėti, kad jos būtų kokybiškai projektuojamos ir programuojamos. Tačiau neišvengiamai atsiranda nekokybiško išeities teksto, arba atsiranda projektavimo trūkumų. Todėl yra svarbu mokėti ieškoti tokias problemas, ir jas ištaisyti. Šio darbo tikslas yra sukurti automatinio – universalaus įrankio modelį, kuris savarankiškai aptiktų pertvarkas, bei būtų nepriklausomas nuo konkrečios programavimo kalbos. Šiam tikslui pasiekti yra nagrinėjami mokslininkų siūlomi automatiškai aptinkantys pertvarkas metodai. Taip pat yra nagrinėjamos tokio įrankio realizavimo galimybės, pateikti realizaciniai sprendimai ir pavyzdžiai. Taip pat tikslas yra sukurti praktiškai naudingas automatines pertvarkas, kurios būtų realizuotos pasiūlytu įrankiu, ir pademonstruotas jų veikimas. Šis įrankis naudoja loginį programavimą, kurio faktais yra aprašomos pertvarkomos programos, o taisyklėmis – pačios pertvarkų programos. Sėkmingai sukurti automatiniai pertvarkų radimo pavyzdžiai, leidžia daryti išvadą, kad šiame darbe rastas būdas automatiškai aptikti nekokybišką išeities tekstą, bei realizuoti tokias pertvarkas nepriklausomai nuo programavimo kalbos. / In the continual evolution of software systems, should be continuous to ensure that they are high quality designed and programmed. But inevitably the defective code, that call “bad small” or the design deficiencies. It is therefore important to be able to find such problems, and to correct them. The aim of this thesis is to create automatic - universal refactoring tool, which is detected in self-refactoring, and is independent of specific programming languages. To achieve this objective are scientists considered the proposed automatic detection of refactoring methods. It is also considered the possibility of the realization of such a tool, to provide examples and realizable solutions. It also aims to create a practical benefit of the automatic adjustments to the proposed tool is to be realized, and a demonstration of their operation. This tool uses a logic programming, which is a factual description of the conversion, and the rules - the refactoring of the program. The successful creation of automatic detection for refactoring, it can be concluded that this work is found way to automatically detect poor quality of source code, and the realization of the restructuring, regardless of programming language.
102

Using Verbal Protocol Analysis to Explore Canadian Consumers' Comprehension of the Nutrition Facts Table

French, Laura J 13 August 2012 (has links)
The current study compared participants’ ability to perform tasks using two nutrition labels: a control Nutrition Facts table of the current Canadian format (n=64), and an experimental label (n=64), identical to the control label with the exception of a footnote explaining how to interpret percent daily values. A 25% subset of participants answered questions using a think aloud technique, and data was analyzed using content analysis. The main outcome measured was ability to interpret percentages correctly, with ability to compare, define and manipulate information as secondary outcomes. No significant differences were seen in ability to perform tasks between the experimental and control conditions for any outcomes. As determined by chi square tests, higher performance was associated with higher education, being male, and report of previous Nutrition Facts table use. Verbal protocol analysis identified that interpretation of percentages was based on the meal, food type, and comparison to other foods.
103

ANALYSIS, DESIGN, AND LABORATORY EVALUATION OF A DISTRIBUTED UNIFIED POWER FLOW CONTROLLER CONCEPT

Li, Qiang 01 January 2006 (has links)
A single-phase, buck-boost based, dual-output AC-DC converter is studied in this thesis. The converter has two DC outputs with opposite polarities, which share the same ground with the input power line. The power stage performance, including the input filter, is studied and procedure to select power components is given. The circuit model is analyzed to develop appropriate control. Zerocrossing distortion of the source input current is addressed and a solution is proposed. Experimental results are satisfactory in that a high power factor line current results for steady-state operation.
104

Exploring young black persons' narratives about the apartheid past / C.M. Petersen

Petersen, Cheryl Marcelle January 2009 (has links)
The extant of available South African qualitative research which investigates issues of the post-apartheid youth appears to be diversified and increasing. A part of this corpus of research, seem to inform on post-apartheid identity formation. This current research explored the narrative forms located in the retellings of the apartheid past by 13 young black South Africans aged between 16 and 21. To this end, 68 different secondary narrative segments were obtained, by means of the analysed transcripts of in-depth interviewing, using a qualitative categorical-content framework. The data analysis yielded 12 themes, wherein the youth identified the primary narrators of the apartheid stories; contextualised settings and circumstances around narratives and explained apartheid social stratifications and treatment of black persons. They also conceptualized their understanding of apartheid laws and enforcement; explained apartheid experienced forms of loss and support; discussed apartheid education; talked about political figures and liberation; disclosed their own feelings about these stories; disclosed the impacts of stories on their own lives; considered the relevance of these narratives; stated what was learnt from it and provided a gauge of their interest in such stories. The findings suggest socially constructed second order narratives of racial hierarchies; marginalising the 'other'; vicarious experiences of affect; the incorporation of the logic of difference and a coexistence of tensions between these stories and present lifestyles. The research has located specific tones, imagery and themes within these narratives, which were duly incorporated in the metastory of this research. Recommendations were made concerning further research to be inclusive of youth from a wider racial and cultural spectrum, as well as investigation into aspects of non-interest and denialism about the apartheid past. / Thesis (M.A. (Research Psychology))--North-West University, Potchefstroom Campus, 2010.
105

Exploring young black persons' narratives about the apartheid past / C.M. Petersen

Petersen, Cheryl Marcelle January 2009 (has links)
The extant of available South African qualitative research which investigates issues of the post-apartheid youth appears to be diversified and increasing. A part of this corpus of research, seem to inform on post-apartheid identity formation. This current research explored the narrative forms located in the retellings of the apartheid past by 13 young black South Africans aged between 16 and 21. To this end, 68 different secondary narrative segments were obtained, by means of the analysed transcripts of in-depth interviewing, using a qualitative categorical-content framework. The data analysis yielded 12 themes, wherein the youth identified the primary narrators of the apartheid stories; contextualised settings and circumstances around narratives and explained apartheid social stratifications and treatment of black persons. They also conceptualized their understanding of apartheid laws and enforcement; explained apartheid experienced forms of loss and support; discussed apartheid education; talked about political figures and liberation; disclosed their own feelings about these stories; disclosed the impacts of stories on their own lives; considered the relevance of these narratives; stated what was learnt from it and provided a gauge of their interest in such stories. The findings suggest socially constructed second order narratives of racial hierarchies; marginalising the 'other'; vicarious experiences of affect; the incorporation of the logic of difference and a coexistence of tensions between these stories and present lifestyles. The research has located specific tones, imagery and themes within these narratives, which were duly incorporated in the metastory of this research. Recommendations were made concerning further research to be inclusive of youth from a wider racial and cultural spectrum, as well as investigation into aspects of non-interest and denialism about the apartheid past. / Thesis (M.A. (Research Psychology))--North-West University, Potchefstroom Campus, 2010.
106

Rescuing Statistics from the Mathematicians

Bedwell, Mike 12 April 2012 (has links) (PDF)
Drawing on some 30 years’ experience in the UK and Central Europe, the author offers four assertions, three about education generally and the fourth that of the title. There the case is argued that statistics is a branch of logic, and therefore should be taught by experts in such subjects as philosophy and law and not exclusively by athematicians. Education in both Statistics and these other subjects would profit in consequence.
107

Variable Structure Control based FACTS Controller Design

Gang Cao Unknown Date (has links)
Along with the increasing scale of the power system and stressed operation in the transmission network, the stability margin is reduced considerably. As a traditional solution, the constructions of new transmission lines and generators sometimes are constrained by local environmental and regulatory constraints. Another characteristic of a modern network is the higher number of transmission inter-connections which appear in the large-scale power system. As an economic benefit, inter-connection can reduce the cost of electricity and enhance system reliability [1]. Those inter-connected tie lines are operated normally under heavy flow to maximize the usage benefit. This characteristic contributes to the complexity of operating and controlling the system. In recent years, along with the development of power electronic devices, the Flexible AC Transmission Systems (FACTS) has been used in the system as an alternative solution. It can maximize the usage benefit of the HV transmission line and make the large-scale power system more controllable. By using FACTS devices, the system can survive serious system contingencies with real-time control action, instead of providing a large steady state stability margin. Therefore, the system transfer capacity can be significantly increased. Electromechanical oscillations are observed in today's power system; such oscillations are recognized as a major concern in power system operation. Once begun, the oscillations may continue for a while before being halted by the damping torque from the system, or they may continue to grow (inadequate damping) and eventually cause system instability by losing synchronicity. The traditional and widely applied solution for oscillation damping is the Power System Stabilizer (PSS), which is efficient in damping local mode oscillation and inter-area oscillation in certain conditions. In recent years, research and development of the application of FACTS devices in suppressing system oscillations, especially for inter-area mode oscillation damping, has attracted increasing interest [1]. The primary objective of this thesis is to design robust FACTS controllers for enhancing power system dynamic stability by damping low frequency electromechanical oscillations. Recently, various nonlinear control techniques have been applied in power system control. The performance of nonlinear controllers is influenced by the parameter uncertainty and external disturbance. This thesis will present a novel approach of a robust Variable Structure Control (VSC)-based FACTS controller for damping multi-mode oscillations. Robust performances of the proposed controllers in different power systems are demonstrated by computer simulation.
108

Applying advanced methods to power system planning studies

Mr Guang Ya Yang Unknown Date (has links)
No description available.
109

Robust coordinated control of FACTS devices in large power systems

Cai, Lijun. Unknown Date (has links) (PDF)
Essen, University, Diss., 2004--Duisburg.
110

Modelagem dinâmica e controle do compensador série TCSC para utilização em sistemas de distribuição de energia elétrica /

Silva, Luciano de Souza da Costa e. January 2017 (has links)
Orientador: Falcondes José Mendes de Seixas / Resumo: A tese de doutorado tem como objetivo específico a proposição de um sistema de controle digital aplicado ao compensador série TCSC (Thyristor Controlled Series Compensator), cujo efeito é proporcionar regulação de tensão para cargas dinâmicas presentes no sistema de distribuição de energia elétrica, como no caso de partida de motores elétricos. Os estudos teóricos contemplam a análise detalhada do estágio de potência do TCSC operando em regime permanente. Gráficos generalizados indicam o comportamento harmônico, as possibilidades de ressonância paralela, a característica de reatância fundamental e os esforços de tensão e corrente nos elementos do TCSC ideal, base para a especificação dos componentes do estágio de potência do compensador série. Os resultados para operação em regime permanente do protótipo indicam, nas condições de plena carga, nível máximo de compensação capacitiva de 125% e aumento na regulação de tensão na carga de 7,3% quando comparado às condições da linha sem compensação. A operação em malha fechada do compensador série realizada por controladores digitais do tipo proporcional-integral com saturação anti-windup e realimentações via Integradores Generalizados de Segunda Ordem Multirressonante (IGSOM), garantem robustez, boa dinâmica na resposta transitória e erro nulo em regime permanente para a regulação da reatância fundamental do TCSC. Os ensaios experimentais com partidas diretas de motores demonstram o efeito positivo do compensador série na regulação... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

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