This works focusesof the propose and realization device for drive four quadrant bridge convertor with transistors IGBT. Final propose include drive unipolar and bipolar, choice between direct or alternative modulation.

Present graphic requires a lot of optimizations of rendering techniques and mathematical calculations. It is caused by increased requirements of scene's visualization. One of scene's optimizing techniques is the Level of detail. This thesis is focused on methods used by LOD in OpenSceneGraph and OpenGL library. Next it will be described how to choose the right level of detail in a scene. Later it will be explained how to simplify 3D models. These techniques will be implemented in converting tool and demonstrating application. Methods for simplify 3D models will be tested for their speed and quality.

Raytracing is a basic technique for displaying 3D objects. The goal of this thesis is to demonstrate the possibility of implementing raytracer using a programmable GPU. The algorithm and its modified version, implemented using "C for CUDA" language, are described. The raytracer is focused on displaying dynamic scenes. For this purpose the KD tree structure, bounding volume hierarchies and PBO transfer are used. To achieve realistic output, photon mapping was implemented.

Bakgrund och problem: Projekt präglas vanligtvis av en otillräcklig måluppfyllelse, exempelvis gällande tid, kostnad och kvalitet. Detta går även att finna vid anläggnings- och infrastrukturprojekt, vilka dessutom är betydande för samhällets möjligheter för kommunikation och transport. Att infrastrukturprojekt, vilka bedrivs av den offentliga verksamheten Trafikverket, inte uppnår sina mål resulterar i förseningar och att skattepengar inte nyttjas maximalt. Detta tyder även på att projekten är svårstyrda utifrån de föränderliga förutsättningar och risker som präglar projekttypen, vilket gör det relevant att studera ämnet vidare.  Syfte: Syftet med studien är att öka kunskapen om hur styrningen går tillväga vid vägprojekt med fokus på förutsättningar och risker. Detta utförs genom att beskriva hur Trafikverkets process styrs i vägprojekt och identifiera samt analysera förutsättningar och risker som kan påverka projekten. Metod: Studien är en kvalitativ flerfallsstudie inom Trafikverket. Det teoretiska materialet har erhållits från vetenskapliga artiklar, litteratur och rapporter. Det empiriska materialet är insamlat genom ett snöbollsurval där åtta respondenter inkluderades. Totalt genomfördes elva semistrukturerade intervjuer. Webbsidor och dokument är också en del av det empiriskt insamlade materialet. Vid genomförandet av studien har vi utgått ifrån forskningsetiska överväganden och kvalitetskriterier, i syfte att öka dess pålitlighet, trovärdighet, konfirmering och överförbarhet.  Slutsats: Studien konstaterar att vägprojekt styrs utifrån en version av stage-gate-modellen och att det även finns inslag av den agila metoden angående riskhanteringen. Styrtriangelns tre dimensioner tid, kostnad och kvalitet utgör ett fokus inom vägprojekt, dimensionen kvalitet beskrivs däremot som innehåll. Förutom att styrtriangeln består av ett inre beroende finns även en yttre påverkan gentemot andra projekt. Detta innebär att ett projekts styrtriangel har en inverkan på ett annat projekts dimensioner, vilket är ett teoretiskt bidrag som studien belyst. Det identifierades även totalt åtta förutsättningar, sex risker och åtta faktorer som betraktas vara både förutsättningar och risker inom vägprojekt. Samtliga av dessa förutsättningar och risker styrs samt hanteras. Det redogörs för att dessa påverkar varandra, vilket styrningen av dem bör ta hänsyn till. Sammantaget fastställs det att styrningen av vägprojekt är komplext på grund av dessa samband och uppkomsten av oförutsägbara händelser. Detta bidrar till en praktisk och teoretisk kunskap angående styrningen med hänsyn till förutsättningar och risker eftersom dessa har studerats i samband med varandra. / Background and problem: Projects are usually characterized by insufficient goal fulfillment, regarding time, cost and quality for example. This can also be found in construction and infrastructure projects, which are important for society's opportunities for communication and transport. The fact that infrastructure projects, which are carried out by the public authority Trafikverket, do not achieve their goals, results in delays and that tax money is not used to the maximum. This also indicates that the projects are difficult to manage on the basis of the changing conditions and risks that characterize the project type, which makes it relevant to study the subject further. Purpose: The purpose of the study is to increase the knowledge of how management is used in road projects with a focus on conditions and risks. This is accomplished by describing how Trafikverkets process is managed in road projects and identifying and analyzing conditions and risks that can affect the projects. Method: The study is a qualitative multi-case study within Trafikverket. The theoretical material has been obtained from scientific articles, literature and reports. The empirical material was collected through a snowball selection in which eight respondents were included. In total, eleven semi-structured interviews were conducted. Web pages and documents are also part of the empirically collected material. In conducting the study, we included research ethical considerations and quality criteria, with the aim of increasing its reliability, credibility, confirmation and transferability. Conclusion: The study finds that road projects are managed based on a version of the stage-gate model and that there are also elements of the agile method regarding risk management. The three dimensions in the iron triangle time, cost and quality are a focus within road projects, but the quality dimension is described as content. In addition to the iron triangle consisting of an internal dependency, there is also an external influence on other projects. This means that one project's control triangle has an impact on another project's dimensions, which is a theoretical contribution that the study illustrated. A total of eight conditions, six risks and eight factors were also identified, which are considered to be both conditions and risks in road projects. All of these conditions and risks are managed. It is stated that these affect each other, which their management should take into account. Overall, it is determined that the management of road projects is complex due to these relationships and the occurrence of unpredictable events. This contributes to a practical and theoretical knowledge of the management with regard to the conditions and risks as these have been studied in conjunction with each other.

The study investigated South African Grade 10 Physical science learners’ reasoning about basic chemical phenomena at sub-microscopic level. The study adopted a non-experimental, exploratory and descriptive method and was principally guided by the ex-post facto research design using a concurrent embedded strategy of mixed qualitative and qualitative approach. A total of 280 grade 10 physical science learners in their intact classes and six of their teachers participated in the study. The 280 physical science learners comprised of 100 students from two top performing schools, 100 learners from two middle performing schools and the last 80 learners were drawn from two poor performing schools in Gauteng Department of Education’s Tshwane North District. A two-tier multiple-choice paper and pencil Test of Basic Chemistry Knowledge (TBCK) based on the three levels of chemical representation of matter was administered to the 280 physical science learners in their Grade 11 first term to collect both quantitative and qualitative data. In addition to the TBCK, focus group discussions (FGDs) with learners, teacher interviews and document analysis were used to triangulate data. The results revealed that most Grade 10 learners find it easy to identify pure elements and the solid state but find it difficult to negotiate between the three levels (macroscopic, sub-microscopic and symbolic) of chemical representation of matter. It became clear that learners experienced more difficulties in the concepts of basic solutions, acidic solutions, concentration and ionic compounds in solution. It also became apparent that some learners could not tell differences between a diatomic element and a compound indicating conceptual problems when they reason at particle level, and as a result they could not identify a mixture of elements. The results also indicated that the concepts of pure compounds and mixtures of compounds were not easy to comprehend as most learners took a pure compound for a mixture of atoms and a mixture of compounds for a mixture of elements. It is therefore concluded that learners find it difficult negotiating the three levels of chemical representation of matter. However, it is not clear whether the misconceptions the learners showed could be completely attributable to the concepts involved or the nature of the sub-microscopic models that were used in the test as it was also revealed that most teachers were not using sub-microscopic representations during instruction to enable learners to think at particle level. Furthermore, justifications to the multiple-choice tasks revealed lack of understanding of basic chemical concepts as well as language problems amongst learners as they could not clearly express their reasoning. Based on the results, some recommendations to educators, chemistry curriculum planners, teacher education and the chemistry education research field are suggested. / Science and Technology Education / D. Phil. ((Philosophy in Mathematics, Science and Technology Education)

I dagens skola finns ingen entydig uppfattning om hur den första skrivinlärningen ska ske, med penna och papper eller med hjälp av digitala verktyg. Syftet med denna studie är att jämföra elevtexter från årskurs 3 skrivna efter traditionell skrivundervisning och metoden Att skriva sig till läsning (ASL). Frågeställningarna i studien handlar om skillnader mellan olika kategorier skrivares texter utifrån helhet och struktur, meningar, ord samt tecken. Studiens teoretiska utgångspunkt är det sociokulturella perspektivet med medierande resurser, och texttriangeln används som teoretisk analysmodell. Materialet som ligger till grund för denna studie är 24 elevtexter från nationella provet i svenska i årskurs 3. Texterna är hämtade från fyra klasser där två fått traditionell skrivundervisning och två undervisats efter ASL-metoden. Från varje klass finns två elevtexter skrivna av säkra skrivare, två av medelsäkra skrivare och två av mindre säkra skrivare. Texterna är analyserade utifrån texttriangeln med hjälp av lix-generatorn och Word. Resultatet i studien är tvetydigt och visar inte vilken skrivundervisningsmetod som är mest fördelaktig för textens helhet. Vidare visar resultatet att ASL-metoden är gynnsam för elevtexters längd och ordvariation samt användandet av styckeindelning och talstreck. Eleverna som undervisats efter denna metod skriver dessutom längre grafiska och syntaktiska meningar. Resultatet visar också att traditionell skrivundervisning gynnar elevers stavning. Dock finns det inga tydliga skillnader mellan metoderna när det gäller elevtexternas andel långord och teckenfel. Slutligen visar resultatet att skrivundervisningsmetoderna kan vara fördelaktiga för olika kategorier skrivare.

Nights in The City Beautiful is a collection of confessional, free verse poems that explores sexual trauma, mental health, the exigencies of marriage, and the complexities of human desire. These interconnected poems are grounded with a braided narrative and tackle taboo themes. In Part 1: Monogamy, the reader journeys into the world of Vincent and Victoria, their profound love, and their anxiety disorders. In Part 2: Polyamory, Victoria gets caught in a love triangle when she meets her publishing coworker, Peter Langley. The book evokes the movement of Romanticism and first-and-second-generation Romantic poets such as William Blake and Lord Byron. Contemporary influences on this collection include Aaron Smith’s Primer, Stacey Waite’s Butch Geography, and Tracy K. Smith’s The Body's Question. Nights in The City Beautiful merges lyricism with narrative, the ethereal with the physical. It is a novella in verse that delves into the boundaries of sexuality, love, and intimacy.

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[pt] O principal objetivo desta dissertação é realizar a previsão da reserva IBNR. Para isto foi desenvolvido um modelo estatístico de distribuições combinadas que busca uma adequada representação dos dados. A reserva IBNR, sigla em inglês para Incurred But Not Reported, representa o montante que as seguradoras precisam ter para pagamentos de sinistros atrasados, que já ocorreram no passado, mas ainda não foram avisados à seguradora até a data presente. Dada a importância desta reserva, diversos métodos para estimação da reserva IBNR já foram propostos. Um dos métodos mais utilizado pelas seguradoras é o Método Chain Ladder, que se baseia em triângulos run-off, que é o agrupamento dos dados conforme data de ocorrência e aviso de sinistro. No entanto o agrupamento dos dados faz com que informações importantes sejam perdidas. Esta dissertação baseada em outros artigos e trabalhos que consideram o não agrupamento dos dados, propõe uma nova modelagem para os dados não agrupados. O modelo proposto combina a distribuição do atraso no aviso da ocorrência, representada aqui pela distribuição log-normal truncada (pois só há informação até a última data observada); a distribuição da quantidade total de sinistros ocorridos num dado período, modelada pela distribuição Poisson; e a distribuição do número de sinistros ocorridos em um dado período e avisados até a última data observada, que será caracterizada por uma distribuição Binomial. Por fim, a quantidade de sinistros IBNR foi estimada por método e pelo Chain Ladder e avaliou-se a capacidade de previsão de ambos. Apesar da distribuição de atrasos do modelo proposto se adequar bem aos dados, o modelo proposto obteve resultados inferiores ao Chain Ladder em termos de previsão. / [en] The main objective of this dissertation is to predict the IBNR reserve. For this, it was developed a statistical model of combined distributions looking for a new distribution that fits the data well. The IBNR reserve, short for Incurred But Not Reported, represents the amount that insurers need to have to pay for the claims that occurred in the past but have not been reported until the present date. Given the importance of this reserve, several methods for estimating this reserve have been proposed. One of the most used methods for the insurers is the Chain Ladder, which is based on run-off triangles; this is a format of grouping the data according to the occurrence and the reported date. However this format causes the lost of important information. This dissertation, based on other articles and works that consider the data not grouped, proposes a new model for the non-aggregated data. The proposed model combines the delay in the claim report distribution represented by a log normal truncated (because there is only information until the last observed date); the total amount of claims incurred in a given period modeled by a Poisson distribution and the number of claims occurred in a certain period and reported until the last observed date characterized by a binomial distribution. Finally, the IBNR reserve was estimated by this method and by the chain ladder and the prediction capacity of both methods will be evaluated. Although the delay distribution seems to fit the data well, the proposed model obtained inferior results to the Chain Ladder in terms of forecast.

[pt] As Américas estão passando pela maior crise de refugiados da história, sendo caracterizada pela elevada presença de crianças desacompanhadas em migração. Este trabalho busca realizar um estudo comparativo entre as políticas de acolhimento para esse grupo, considerando refugiados venezuelanos no Brasil e do Triângulo Norte da América Central nos EUA. Examinou-se se os processos de acolhida e suas aplicações são inclusivos e adequados a recepção de menores desacompanhados, à luz das diretrizes de organismos de referência na área. Este estudo conclui que os processos de acolhida brasileiros almejam ser receptivos e inclusivos, seguindo o princípio do melhor interesse da criança. No entanto, os procedimentos carecem maior robustez e estrutura para serem eficazes. Enquanto isso, as políticas de acolhimento nos EUA são mais amadurecidas e possuem os recursos necessários para sua implementação. Entretanto, o acolhimento é hostil, assemelhando-se ao processo de detenção, não havendo distinção institucional clara entre a proteção da criança refugiada e o controle de fronteiras / [en] The Americas are experiencing the worst refugee crisis in history, characterized by the elevated presence of unaccompanied children. This work seeks to conduct a comparative study between reception policies for this group, considering Venezuelans in Brazil and nationals from the Northern Triangle of Central America in the USA. It was examined whether the reception processes and their applications are inclusive and adequate for unaccompanied minors, in light of the guidelines of reference organizations in the area. This study concludes that the Brazilian reception process aims to be receptive and inclusive, following the principle of the best interest of the child. However, the procedures lack more robustness and structure to be effective. Reception policies in the US are more mature and have the resources available for implementation. However, the reception is hostile, similar to the detention process, with no institutional distinction between refugee child protection and border control.