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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.
1

Non-native speakers and virtual language learning environment : user behaviours and social discourse

Zhang, Qing January 2003 (has links)
No description available.
2

Evolutionary multi-objective decision support systems for conceptual design

Cvetkovic, Dragan January 2000 (has links)
In this thesis the problem of conceptual engineering design and the possible use of adaptive search techniques and other machine based methods therein are explored. For the multi-objective optimisation (MOO) within conceptual design problem, genetic algorithms (GA) adapted to MOO are used and various techniques explored: weighted sums, lexicographic order, Pareto method with and without ranking, VEGA-like approaches etc. Large number of runs are performed for findingZ Dth e optimal configuration and setting of the GA parameters. A novel method, weighted Pareto method is introduced and applied to a real-world optimisation problem. Decision support methods within conceptual engineering design framework are discussed and a new preference method developed. The preference method for translating vague qualitative categories (such as "more important 91 , 4m.9u ch less important' 'etc. ) into quantitative values (numbers) is based on fuzzy preferences and graph theory methods. Several applications of preferences are presented and discussed: * in weighted sum based optimisation methods; s in weighted Pareto method; * for ordering and manipulating constraints and scenarios; e for a co-evolutionary, distributive GA-based MOO method; The issue of complexity and sensitivity is addressed as well as potential generalisations of presented preference methods. Interactive dynamical constraints in the form of design scenarios are introduced. These are based on a propositional logic and a fairly rich mathematical language. They can be added, deleted and modified on-line during the design session without need for recompiling the code. The use of machine-based agents in conceptual design process is investigated. They are classified into several different categories (e. g. interface agents, search agents, information agents). Several different categories of agents performing various specialised task are developed (mostly dealing with preferences, but also some filtering ones). They are integrated with the conceptual engineering design system to form a closed loop system that includes both computer and designer. All thesed ifferent aspectso f conceptuale ngineeringd esigna re applied within Plymouth Engineering Design Centre / British Aerospace conceptual airframe design project.
3

Thirdspaces, Tactics and Bricolage: A Postmodern Identity Construction in the Composition Classroom

Lauer, Claire January 2006 (has links)
In this dissertation, Claire Lauer proposes a spatial-metaphorical model for exploring and communicating the self in composition. She uses the concepts of Edward Soja's Thirdspace, Michel de Certeau's tactics, and Turkle and Papert's bricolage as lenses through which to analyze and understand the spatial-metaphorical self-constructions that students in her classes built in the virtual reality of the MOO. These lenses reveal a new kind of agency, one that finds power in complexity and refuses reduction. Through their sites, students show themselves to be comfortable with the unfamiliar and the ambiguous, but also able to adapt, change shape, and see the I as an all--as an infinite sum and ever-changing total. Lauer argues that offering students the opportunity to construct themselves spatially and metaphorically disrupts their assumptions about identity and provides them with new ways of expressing their postmodern subjectivities--of speaking to and about their ever-shifting proximities to the people and events in their lives.Lauer argues that recognizing the complexity of identity facilitates a recognition of the complexity of culture and communication, and shows how identity construction assignments can thus serve as models for larger knowledge exploration and construction. She concludes by arguing that the analysis and production of new media in the composition classroom is essential to the continued goal of composition instructors fostering critical engagement in the classroom. As an extension of identity investigation, such engagement should be a cornerstone of first-year composition and does not have to be at odds with the more practical work of preparing students for their academic careers. In fact, it facilitates the more practical work instructors do in composition because it allows students to see the constructed nature of all discourses and become aware of how we both compose and are composed by the texts we encounter.
4

An investigation of learner interaction in a MOO-based virtual environment

Peterson, Mark January 2008 (has links)
This study investigated how EFL learners managed their real time interaction in a computer-mediated communication (CMC) environment called Schmooze University MOO. Fourteen undergraduates enrolled at two universities in Tokyo took part in weekly text chat sessions over a semester. Four task types were implemented; information-gap, jigsaw, decision-making and opinion-exchange. Qualitative data such as transcripts, field notes and questionnaires were analyzed within the framework of a case study. Findings indicated that the subjects actively managed their interaction, monitored their linguistic output, supported each other and exercised autonomy. Analysis of the transcripts revealed that the subjects consistently produced coherent target language output focused on the tasks, while at the same time, overcoming the challenge of communicating effectively in a new online environment. They achieved this considerable feat in part, by utilizing features of the environment designed to facilitate interaction. Moreover, they utilized a mix of transactional and interactional discourse management strategies that have been identified in the literature on native speaker interaction in real time CMC. Transactional strategies identified in the data were addressivity, time saving and feedback. Interactional strategies were the use of pseudonyms, positive and negative politeness, greetings, leave-takings and off-task discussion. These strategies enabled the subjects to track turns, provide feedback and build the social cohesion necessary for sustained communication in online environments. The analysis showed that as the project progressed, the subjects utilized a greater number and wider range of strategies than in the earlier sessions. The majority of these appeared the result of transfer from conventional forms of communication. However, others were adaptive and appropriate to the online nature of the interaction. These strategies that have not been reported in the literature on learner-learner interaction in CMC, were use of the to command, split turns, suspension dots, quotation and omission. The appearance of these medium induced strategies highlights the subjectsʼ increasingly sophisticated and successful attempts to deal with real time computer-based nature of the interaction. Analysis of the data further revealed that when communication problems arose the subjects overcome them by utilizing communication strategies involved in negotiation of meaning. The most frequent strategies identified in the data were definition and clarification requests followed by self-, other-initiated correction and non-response. The subjects also made limited use of confirmation and comprehension checks. These strategies were more frequent in the jigsaw tasks than in the other task types. The data showed that learner-learner negotiation in this type of CMC broadly follows the model proposed for face-to-face interaction in conventional classrooms. However, analysis indicated that the interplay of proficiency levels, task, the computer-based nature of the interaction and sociocultural concerns appeared to influence the frequency of negotiation.
5

Otimização acústica e análise numérica do escoamento ao redor de um conjunto cilindro-placa separadora. / Accoustic optimization and numerical analysis of a detached splitter plate applied for passive cylinder wake control.

Nogueira, Leon White 07 August 2015 (has links)
RESUMO Simulações de aeroacústica computacional demandam uma quantidade considerável de tempo, o que torna complicada a realização de estudos paramétricos. O presente trabalho propõe uma metodologia viável para otimização aeroacústica. Através da análise numérica utilizando dinâmica dos fluidos computacional, foi estudada a aplicação de uma placa separadora desacoplada como método de controle passivo da esteira turbulenta de um cilindro e avaliou-se a irradiação de ruído causado pela interação do escoamento com ambos os corpos, empregando ferramentas de aeroacústica computacional baseadas no método de Ffowcs-Williams e Hawkings. Algumas abordagens distintas de metodologias de otimização de projeto foram aplicadas neste problema, com o objetivo de chegar a uma configuração otimizada que permita a redução do nível sonoro ao longe. Assim, utilizando uma ferramenta de otimização multidisciplinar, pode-se avaliar a capacidade de modelos heurísticos e a grande vantagem do emprego de algoritmos baseados em método de superfície de resposta quando aplicados em um problema não linear, pois requerem a avaliação de um menor número de alternativas para se obter um ponto ótimo. Além disso, foi possível identificar e agrupar os resultados em 5 clusters baseados em seus parâmetros geométricos, nível de pressão sonora global e o valor quadrático médio do coeficiente de arrasto, confirmando a eficiência da aplicação de placas separadoras longas desacopladas posicionadas próximas ao cilindro na estabilização da esteira turbulenta, enquanto que o posicionamento de placas acima de um espaçamento crítico aumentou o nível de pressão acústica irradiado devido à formação de vórtices no espaço entre o cilindro e a placa separadora. / Computational aeroacoustics simulations require a considerable amount of time, which makes the comparison of a large number of different geometric designs a difficult task. The goal of the present study is to provide a suitable methodology for aeroacustic optimization. By means of numerical analyses using computational fluid dynamics tools, the application of a detached splitter plate as a passive control method for the turbulent wake of a circular cylinder was investigated. The irradiation of noise caused by the interaction between the flow and both bodies was evaluated using computational aeroacoustics tools based on the Ffowcs-Williams and Hawkings method. Various design optimization methodologies were applied to this flow in order to achieve a possible optimal configuration, i.e., one which is capable of reducing the far field noise level without increasing the aerodynamic forces. Using a multidisciplinary optimization tool, it was possible to evaluate the behavior of heuristic optimization algorithms and the major advantage of algorithms based on response surface methods when applied to a nonlinear aeroacoustics problem, since they require a smaller number of calculated designs to reach the optimal configuration. In addition, it was possible to identify and group the outcomes into 5 clusters based on their geometric parameters, overall sound pressure level and drag coefficient, confirming the efficiency of the application of long detached splitter plates placed next to the cylinder in stabilizing the turbulent wake, whereas the positioning of splitter plates at a distance larger than a critical gap increased the overall sound pressure level radiated due to the formation of vortices in the gap.
6

Otimização acústica e análise numérica do escoamento ao redor de um conjunto cilindro-placa separadora. / Accoustic optimization and numerical analysis of a detached splitter plate applied for passive cylinder wake control.

Leon White Nogueira 07 August 2015 (has links)
RESUMO Simulações de aeroacústica computacional demandam uma quantidade considerável de tempo, o que torna complicada a realização de estudos paramétricos. O presente trabalho propõe uma metodologia viável para otimização aeroacústica. Através da análise numérica utilizando dinâmica dos fluidos computacional, foi estudada a aplicação de uma placa separadora desacoplada como método de controle passivo da esteira turbulenta de um cilindro e avaliou-se a irradiação de ruído causado pela interação do escoamento com ambos os corpos, empregando ferramentas de aeroacústica computacional baseadas no método de Ffowcs-Williams e Hawkings. Algumas abordagens distintas de metodologias de otimização de projeto foram aplicadas neste problema, com o objetivo de chegar a uma configuração otimizada que permita a redução do nível sonoro ao longe. Assim, utilizando uma ferramenta de otimização multidisciplinar, pode-se avaliar a capacidade de modelos heurísticos e a grande vantagem do emprego de algoritmos baseados em método de superfície de resposta quando aplicados em um problema não linear, pois requerem a avaliação de um menor número de alternativas para se obter um ponto ótimo. Além disso, foi possível identificar e agrupar os resultados em 5 clusters baseados em seus parâmetros geométricos, nível de pressão sonora global e o valor quadrático médio do coeficiente de arrasto, confirmando a eficiência da aplicação de placas separadoras longas desacopladas posicionadas próximas ao cilindro na estabilização da esteira turbulenta, enquanto que o posicionamento de placas acima de um espaçamento crítico aumentou o nível de pressão acústica irradiado devido à formação de vórtices no espaço entre o cilindro e a placa separadora. / Computational aeroacoustics simulations require a considerable amount of time, which makes the comparison of a large number of different geometric designs a difficult task. The goal of the present study is to provide a suitable methodology for aeroacustic optimization. By means of numerical analyses using computational fluid dynamics tools, the application of a detached splitter plate as a passive control method for the turbulent wake of a circular cylinder was investigated. The irradiation of noise caused by the interaction between the flow and both bodies was evaluated using computational aeroacoustics tools based on the Ffowcs-Williams and Hawkings method. Various design optimization methodologies were applied to this flow in order to achieve a possible optimal configuration, i.e., one which is capable of reducing the far field noise level without increasing the aerodynamic forces. Using a multidisciplinary optimization tool, it was possible to evaluate the behavior of heuristic optimization algorithms and the major advantage of algorithms based on response surface methods when applied to a nonlinear aeroacoustics problem, since they require a smaller number of calculated designs to reach the optimal configuration. In addition, it was possible to identify and group the outcomes into 5 clusters based on their geometric parameters, overall sound pressure level and drag coefficient, confirming the efficiency of the application of long detached splitter plates placed next to the cylinder in stabilizing the turbulent wake, whereas the positioning of splitter plates at a distance larger than a critical gap increased the overall sound pressure level radiated due to the formation of vortices in the gap.
7

När 600 kilo gräsätande klövdjur blir ett barn - Vilka retoriska medel används för att möjliggöra identifikationen mellan läsaren och Mamma Mu?

Dalic, Zarko January 2009 (has links)
<p>Uppsatsens syfte är att undersöka vilka retoriska medel som används för att möjliggöra identifikationen mellan läsaren och huvudkaraktären Mamma Mu.</p><p> Uppsatsen använder sig av teorier om berättelser och identifikation, framhållna av Jerome Bruner, Kenneth Burke, och Maria Nikolajeva. Eftersom uppsatsen rör sig inom ett nytt område har jag tagit fram en egen analysmodell. Den gör det möjligt att urskilja <em>identifikationstecken </em>utifrån kategorierna <em>yttre</em>, <em>inre</em>, och <em>aktiviteter</em>.</p><p>Slutsatsen är att det i boken tillämpas <em>antites </em>för att distansera Mamma Mu från hennes egentliga form och de andra korna; <em>imitatio </em>för att barnen ska kunna känna igen sig i Mamma Mus agerande; <em>topos </em>för att visa att Mamma Mu har samma intressen som läsaren, <em>upprepning </em>för att kontinuerligt bekräfta att Mamma Mu är ett barn; <em>entymem </em>för att läsaren ska själv komma till slutsatsen att Mamma Mu är ett barn.</p> / <p>The purpose of this essay is to examine which rhetoric devices are being put in use to make possible the process of identification between the reader and the main character Mamma Moo.</p><p>The essay uses theories of narrative and identification represented by Jerome Bruner, Kenneth Burke, and Maria Nikolajeva. Because there is no previous research in the essays area, I have brought forward a new model to analyse the material. It is used to  discover <em>identification signs</em>, based on the categories <em>outer</em>, <em>inner</em>, and <em>activities</em>.</p><p>The conclusion is that the book utilizes <em>antitheses </em>to separate Mamma Moo from her original form and the other cows; <em>imitatio </em>to make it possible for the children to recognize themselves in Mamma Moos behaviour; <em>topos </em>to show that Mamma Moo has the same interests as the reader; <em>repetition </em>to continuously confirm that Mamma Moo is a child; <em>entymem </em>to make the reader come to the conclusion that Mamma Moo is a child.</p>
8

När 600 kilo gräsätande klövdjur blir ett barn - Vilka retoriska medel används för att möjliggöra identifikationen mellan läsaren och Mamma Mu?

Dalic, Zarko January 2009 (has links)
Uppsatsens syfte är att undersöka vilka retoriska medel som används för att möjliggöra identifikationen mellan läsaren och huvudkaraktären Mamma Mu.  Uppsatsen använder sig av teorier om berättelser och identifikation, framhållna av Jerome Bruner, Kenneth Burke, och Maria Nikolajeva. Eftersom uppsatsen rör sig inom ett nytt område har jag tagit fram en egen analysmodell. Den gör det möjligt att urskilja identifikationstecken utifrån kategorierna yttre, inre, och aktiviteter. Slutsatsen är att det i boken tillämpas antites för att distansera Mamma Mu från hennes egentliga form och de andra korna; imitatio för att barnen ska kunna känna igen sig i Mamma Mus agerande; topos för att visa att Mamma Mu har samma intressen som läsaren, upprepning för att kontinuerligt bekräfta att Mamma Mu är ett barn; entymem för att läsaren ska själv komma till slutsatsen att Mamma Mu är ett barn. / The purpose of this essay is to examine which rhetoric devices are being put in use to make possible the process of identification between the reader and the main character Mamma Moo. The essay uses theories of narrative and identification represented by Jerome Bruner, Kenneth Burke, and Maria Nikolajeva. Because there is no previous research in the essays area, I have brought forward a new model to analyse the material. It is used to  discover identification signs, based on the categories outer, inner, and activities. The conclusion is that the book utilizes antitheses to separate Mamma Moo from her original form and the other cows; imitatio to make it possible for the children to recognize themselves in Mamma Moos behaviour; topos to show that Mamma Moo has the same interests as the reader; repetition to continuously confirm that Mamma Moo is a child; entymem to make the reader come to the conclusion that Mamma Moo is a child.
9

Paulus lagsyn i Rom 3:21-31

Amanda, Erlansson January 2015 (has links)
Denna uppsats behandlar Paulus syn på lagen vilket är ett mycket omdebatterat område inom paulusforskningen. Frågan om Paulus lagsyn är så central för den övergripande paulustolkingen att alla som vill förstå Paulus och hans texter måste bilda sig en uppfattning om detta. Det har skrivits många hyllmeter och diskussionen verkar långt ifrån avslutad. Frågan kräver dock tydliga avgränsningar för att kunna behandlas i denna relativt korta uppsats. Därför kommer jag fokusera på en perikop i ett av Paulus brev som behandlar denna fråga. Min frågeställning blir då: Vad menar Paulus med ”lagen” i Rom 3:21-31?
10

A comparative study on the value of accounting for possible relationships between decision variables when solving multi-objective problems

Scholtz, Esmarie 04 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The cross-entropy method for multi-objective optimisation (MOO CEM) was recently introduced by Bekker & Aldrich (2010) and Bekker (2012). Results presented by both show great promise. The MOO CEM assumes that decision variables are independent. As a consequence, the question arises: under which circumstances would an algorithm that accounts for relationships between decision variables outperform the MOO CEM? Two algorithms reported to account for relationships between decision variables, the multi-objective covariance matrix adaptation evolution strategy (MOCMA- ES) and Pareto di erential evolution (PDE), are selected for comparison. In addition, two hybrid algorithms (Hybrid 1 and Hybrid 2) based on the MOO CEM are created. These ve algorithms are applied to a set of 46 continuous problems, six instances of the mission-ready resource (MRR) problem, and three instances of a dynamic, stochastic bu er allocation problem (BAP). Performance is measured using the hypervolume indicator and Mann-Whitney U-tests. One of the primary ndings is that accounting for relationships between decision variables is bene cial when solving small to medium-sized problems. In these cases, the MO-CMA-ES typically outperforms the other algorithms. However, on large problems, Hybrid 1 and the MOO CEM typically perform best. / AFRIKAANSE OPSOMMING: Die kruis-entropie metode vir meerdoelige optimering (MOO CEM) is onlangs deur Bekker & Aldrich (2010) en Bekker (2012) bekendgestel. Hul resultate is belowend. Die MOO CEM neem aan dat besluitnemingsveranderlikes onafhanklik is van mekaar. Gevolglik ontstaan die vraag: onder watter omstandighede sal 'n optimeringsalgoritme wat moontlike verhoudings tussen besluitnemingsveranderlikes in ag neem, beter vaar as die MOO CEM? Twee bestaande algoritmes, beide gerapporteer vir hul vermo e om moontlike verhoudings tussen besluitnemingsveranderlikes in ag te neem, naamlik die meerdoelige optimering kovariansiematriksaanpassing-evolusiestrategie (MO-CMA-ES) en Pareto afgeleide evolusie (PDE), word met die MOO CEM vergelyk. Twee nuwe hibriedalgoritmes (Hibried 1 en Hibried 2) word ook ter wille van di e vergelyking geskep. Die vyf algoritmes word op 'n stel van 46 kontinue probleme, ses statiese kombinatoriese gevalle en drie dinamies, stogastiese gevalle toegepas. Die prestasie van die algoritmes word deur middel van die hipervolume-aanwyser en Mann-Whitney U-toetse gemeet. 'n Prim^ere bevinding is dat dit voordelig is om moontlike verhoudings tussen besluitnemingsveranderlikes in ag te neem wanneer klein na medium-grootte probleme opgelos word. Vir hierdie gevalle presteer die MO-CMA-ES tipies beter as die ander algoritmes. Vir groot probleme presteer Hibried 1 en die MOO CEM beter as die ander algoritmes. / National Research Foundation

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