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Kagdi, Huzefa H. "Mining Software Repositories to Support Software Evolution." Kent State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=kent1216149768.
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Sogbadji, Robert. "Neutronic study of the mono-recycling of americum in PWR and of the core conversion INMNSR using the MURE code." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00843688.
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The MURE code is based on the coupling of a Monte Carlo static code and the calculation of the evolution of the fuel during irradiation and cooling periods. The MURE code has been used to analyse two different questions, concerning the mono-recycling of Am in present French Pressurized Water Reactor, and the conversion of high enriched uranium (HEU) used in the Miniature Neutron Source Reactor in Ghana into low enriched uranium (LEU) due to proliferation resistance issues. In both cases, a detailed comparison is made on burnup and the induced radiotoxicity of waste or spent fuel. The UOX fuel assembly, as in the open cycle system, was designed to reach a burn-up of 46GWd/T and 68GWd/T. The spent UOX was reprocessed to fabricate MOX assemblies, by the extraction of Plutonium and addition of depleted Uranium to reach burn-ups of 46GWd/T and 68GWd/T, taking into account various cooling times of the spent UOX assembly in the repository. The effect of cooling time on burnup and radiotoxicity was then ascertained. Spent UOX fuel, after 30 years of cooling in the repository required higher concentration of Pu to be reprocessed into a MOX fuel due to the decay of Pu-241. Americium, with a mean half-life of 432 years, has high radiotoxic level, high mid-term residual heat and a precursor for other long lived isotope. An innovative strategy consists of reprocessing not only the plutonium from the UOX spent fuel but also the americium isotopes which dominate the radiotoxicity of present waste. The mono-recycling of Am is not a definitive solution because the once-through MOX cycle transmutation of Am in a PWR is not enough to destroy all the Am. The main objective is to propose a "waiting strategy" for both Am and Pu in the spent fuel so that they can be made available for further transmutation strategies. The MOXAm (MOX and Americium isotopes) fuel was fabricated to see the effect of americium in MOX fuel on the burn-up, neutronic behavior and on radiotoxicity. The MOXAm fuel showed relatively good indicators both on burnup and on radiotoxicity. A 68GWd/T MOX assembly produced from a reprocessed spent 46GWd/T UOX assembly showed a decrease in radiotoxicity as compared to the open cycle. All fuel types understudy in the PWR cycle showed good safety inherent feature with the exception of the some MOXAm assemblies which have a positive void coefficient in specific configurations, which could not be consistent with safety features. The core lifetimes of the current operating 90.2% HEU UAl fuel and the proposed 12.5% LEU UOX fuel of the MNSR were investigated using MURE code. Even though LEU core has a longer core life due to its higher core loading and low rate of uranium consumption, the LEU core will have it first beryllium top up to compensate for reactivity at earlier time than the HEU core. The HEU and LEU cores of the MNSR exhibited similar neutron fluxes in irradiation channels, negative feedback of temperature and void coefficients, but the LEU is more radiotoxic after fission product decay due to higher actinides presence at the end of its core lifetime.
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Silva, Ana Paula Ramão da. "Imagens do mar nas crônicas de Rubem Braga." Universidade Estadual de Londrina. Centro de Letras e Ciências Humanas. Programa de Pós-Graduação em Letras, 2005. http://www.bibliotecadigital.uel.br/document/?code=vtls000109865.
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A pesquisa parte de um olhar curioso sobre a presença constante do mar nas crônicas de Rubem Braga. A partir disso, buscou-se entender o porquê dessas imagens e suas possíveis significações. Para tanto, foi necessário começar investigando as peculiaridades da crônica enquanto gênero literário moderno, tais como sua origem e fixação no Brasil e as características de sua linguagem. Num outro momento, foi preciso pesquisar como o mar se construiu enquanto elemento simbólico no imaginário ocidental para então observar sua recorrência em obras literárias de importância no universo cultural. Após essas etapas, analisaram-se as imagens do mar recorrentes nas crônicas de Braga em diálogo com as estudadas nas outras obras.The research comes from a curious look about the constant presence of the sea in Rubem Braga's chronicles. From this, we tried to understand the reason of these images and their possible meanings. To make the deal, it was necessary to start investigating the particularities of the chronicle while modern literary genre, as well as its origin and fixation in Brazil and the language characteristics. In other moment, we needed to find out how the sea was built as a symbolical element in the western world, so then to observe its recurrences in literary works that are important in the cultural universe. After these stages, the images of the sea were analyzed in Braga's chronicles in a dialogue with the ones studied in other works.
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Nerman, Isabell, and Jesper Andersson. "Rättelse i fastighetsregistrets inskrivningsdel : Kan det vara mer rätt att rätta mer?" Thesis, KTH, Fastigheter och byggande, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-298021.
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Av 19 kap. 22 § 1 st. första meningen jordabalken följer att om fastighetsregistrets inskrivningsdel innehåller någon uppenbar oriktighet som beror på inskrivningsmyndighetens eller någon annans skrivfel, på något liknande förbiseende eller på ett tekniskt fel, ska inskrivningsmyndigheten rätta uppgiften. Avseende bestämmelsen ämnar examensarbetet att fastställa gällande rätt (de lege lata), analysera rekvisiten och föreslå regelförändringar(de lege ferenda) som möjliggör att rättelse skulle kunna tillämpas i fler situationer än vad som är möjligt idag. För detta har rättsdogmatisk metod, rättsvetenskaplig metod och empirisk metod använts. Utöver de traditionella rättskällorna inkluderas empiriskt material som underrättspraxis, JO-avgöranden och intervjumaterial. Även rättelsebestämmelserna 36 § förvaltningslagen (2017:900) och 4 kap. 21 § lagen (2008:990) om företagshypotek presenteras som underlag för en avslutande jämförelse. Av slutsatserna framgår bland annat att rättelse ska tillämpas restriktivt, vilketinnebär att endast oriktigheter som tydligt uppfyller rekvisiten kan rättas. Om rättelse skulle tillämpas i fler situationer är det viktigt att den enskildes rättstrygghet inte äventyras då denne kan lida skada efter att ha förlitat sig på registeruppgifter som sedan ändras genom rättelse.19 ch. 22 § in the Land Code (Sw: jordabalken) stipulates that if the land register section of the Real Property Register contains an obvious inaccuracy which depends on the land registration authority or somebody else's clerical error, similar inadvertence or due to a technical error, the land registration authority shall correct the inaccuracy. Regarding this regulation, the purpose of this master’s thesis is to establish the law (de lege lata), analyse the necessary conditions and propose rule changes (de lege ferenda) whether correction could be applied in more situations than what is possible today. Beyond the traditional sources of law, empirical material consisting of lower court praxis, decisions from the Parliamentary ombudsmen and interview material are included. Also, the regulations regarding correction according to 36 § of the Administrative Procedure Act (Sw: förvaltningslagen (2017:900)) and 4 ch. 21 § of the Floating Charges Act (Sw: lag (2008:990) om företagshypotek) are presented as a basis for a concluding comparison. From the conclusion – for instance – it appears that 19 ch. 22 § of the Land Code has a restrictive interpretation, which means that only incorrections that in a clear way fulfil the necessary conditions can be corrected. If correction would be applied in more situations, it is important that the individual legal rights should not be compromised since a third party can suffer loss after relying on information in the register that later will be corrected.
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Bjureland, William. "Analysis of deep excavations using the mobilized strength design(MSD) method." Thesis, KTH, Jord- och bergmekanik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-136584.
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The population in Sweden and around the world is increasing. When population increases, cities become more densely populated and a demand for investments in housing and infrastructure is created. The investments needed are usually large in size and the projects resulting from the investments are often of a complex nature. A major factor responsible for creating the complexity of the projects is the lack of space due to the dense population. The lack of space creates a situation where a very common feature of these types of projects is the use of earth retaining systems. The design of retaining systems in Europe is performed today based on Eurocode. Eurocode is a newly introduced standard for the design of structures and is developed in order to make it easier to work cross borders by using the same principle of design in all countries. For the design of retaining walls in Sweden, Eurocode uses the old standard as the basis of the design procedure consisting of two separate calculations, ultimate limit state and serviceability limit state. Since soil does not consist of two separate mechanisms consisting of failure and serviceability, this approach to solving engineering problems fails to address the real behavior of soils. To handle this problem Bolton et. al. (1990a, 1990b, 2004, 2006, 2008, 2010) developed the theory of “mobilized strength design” where a single calculation procedure incorporates both the calculation of deformations and the safety against failure. The calculation uses conservation of energy and the degree of mobilized shear strength to study deformations in and around the retaining system and the safety against failure in mobilizing the maximum shear strength of the soil. The aim of this thesis was to introduce the theory of mobilized strength design to geotechnical engineers in Sweden working both in academia and in industry. Another aim of the thesis was to develop a tool that could be used to perform calculations of earth retaining systems based on this theory. The development of a working tool has resulted in a Matlab code which can in a simple way be used to calculate both deformations in the retaining system and the safety against failure by using the degree of mobilized shear strength presented in the theory. The Matlab code can handle ground layering with different shear strengths and weights of the soil. A comparison instrument in a Mathcad calculation sheet have been developed to produce results based on the original theory where the feature of soil layering is not incorporated into the calculation procedure. The thesis shows that the Matlab code developed performs well but is not yet sensitive enough to produce the same results as the Mathcad calculation sheet and needs to be further developed to make it more robust in order to handle all different excavation scenarios. v The theory of mobilized strength design has been introduced to geotechnical engineers in Sweden and the thesis studies the theory and shows the calculation procedure and how the different input values and calculations affect the analysis. The thesis also shows some areas in which the theory and the code can be modified and where further research can be performed in order to make them fully applicable to Swedish conditions. As an example the use of rock dowels drilled into the bedrock and attached to the retaining structure is a common feature for deep excavations in Sweden. Further research can be pursued on how to incorporate the energy stored in the rock dowels into the calculation procedure.
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Leydold, Josef, Gerhard Derflinger, Günter Tirler, and Wolfgang Hörmann. "An Automatic Code Generator for Nonuniform Random Variate Generation." Department of Statistics and Mathematics, Abt. f. Angewandte Statistik u. Datenverarbeitung, WU Vienna University of Economics and Business, 2001. http://epub.wu.ac.at/364/1/document.pdf.
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There exists a vast literature on nonuniform random variate generators. Most of these generators are especially designed for a particular distribution. However in pratice only a few of these are available to practioners. Moreover for problems as (e.g.) sampling from the truncated normal distribution or sampling from fairly uncommon distributions there are often no algorithms available. In the last decade so called universal methods have been developed for these cases. The resulting algorithms are fast and have properties that make them attractive even for standard distributions. In this contribution we describe the concept of Automatic random variate generation where these methods are used to produce a single piece of code in a high level programming language. Using a web-based front-end to such a program this is an easy-to-use source for researchers and programmers for high quality generators for a large class of distributions. Using our UNURAN library we have implemented such a system, which is accessable at http://statistik.wu-wien.ac.at/anuran.Series: Preprint Series / Department of Applied Statistics and Data Processing
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Ferreira, Guadalupe Estrelita dos Santos Menta. "O universo simbólico na viagem de Mãe, materno mar : nos trilhos do imaginário bantu." Universidade Estadual de Londrina. Centro de Letras e Ciências Humanas. Programa de Pós-Graduação em Letras, 2011. http://www.bibliotecadigital.uel.br/document/?code=vtls000161472.
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A presente pesquisa busca, por meio da literatura, reconhecer elementos da cultura africana, particularmente de Angola, cujas marcas de matriz bantu estão presentes na formação cultural brasileira. A obra escolhida como corpus, Mãe, Materno Mar, de Boaventura Cardoso, desenovela os fios da narrativa, em cujo tecido dialogam modernidade e tradição, tendo, sobretudo no imaginário bantu, esse processo interlocutório com a memória do povo, o que permite a permanência da tradição e a afirmação de uma identidade, por tanto tempo sufocada pela opressão colonialista. As peculiaridades da cultura bantu, em seus aspectos também religiosos, e o universo simbólico que reveste a narrativa servem de base para a compreensão das correspondências do inconsciente com o imaginário e a memória do povo angolano. Como se trata de uma obra em que a História se transfigura em uma viagem alegórica no microcosmo da sociedade angolana, encontra-se, no engajamento, uma literatura empenhada, mas reconhecidamente arte, cujo compromisso com sua escrita em processo permite recontar a história de seu povo, quem sabe reavivando as esperanças que porventura se dispersaram pelo caminho.This research aims, by means of the literature, to recognize elements of the African culture, particularly in Angola, whose signs of the Bantu matrix are present in the formation of the Brazilian culture. The chosen corpus, Mãe, Materno Mar, by Boaventura Cardoso, unrolls the threads of the narrative, where modernity and tradition dialogue, having especially in the Bantu imaginary this interlocutory process with the memory of the people, allowing the persistence of tradition and affirmation of an identity suppressed by the colonialist oppression for such a long time. The peculiarities of the Bantu culture in its religious aspects, and the symbolic universe that pervades the narrative provide the basis for the understanding of connections among the unconscious and the imaginary and the memory of the Angolan people. As this is a work in which history is transformed into an allegorical journey into the microcosm of the Angolan society, a committed literature is found, but admittedly art, whose commitment to its writing in process permits retelling the story of its people, perhaps reviving the hopes that were eventually dispersed along the way.
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Braga, Patrícia Benedita Aparecida. "A grande casa no fundo do mar : Tuvalu e os impasses políticos ambientais contemporâneos." Universidade Estadual de Londrina. Centro de Letras e Ciências Humanas. Programa de Pós-Graduação em Ciências Sociais, 2012. http://www.bibliotecadigital.uel.br/document/?code=vtls000178987.
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Partindo do fato de que a mudança climática global é uma realidade, e de que a sua origem pode estar relacionada a fatores antropogênicos e a dinâmicas próprias do planeta, pode-se afirmar que, na atualidade, pós 1989, as resoluções científicas de um determinado grupo de pesquisadores do Painel Intergovernamental sobre Mudança do Clima (IPCC) fundamentam dados científicos que são utilizados em ações políticas planetárias, criando remodelações na economia mundial e influenciando ações sociais e culturais em nível global, regional e local. As afirmativas científicas ambientais e a mudança climática encontram-se inseridas em um meio político de ações globais, caracterizado primordialmente pela assimetria de poder, transversalidade e transnacionalidade de ações. Deste modo, os fenômenos de variação climática, que afetam o Estado-ilha Tuvalu, assim como as possíveis soluções para o problema climático/político do país, estão relacionados a ações estatais e a processos deliberativos em Organizações Internacionais. O princípio de cidadania vinculado aos Estados nacionais é fragmentado, uma vez que, internamente, o Estado tuvaluano, ao perder o seu território com a elevação do nível do mar, não consegue garantir, aos seus cidadãos, o direito à vida e a permanência destes em seu território. Frágil em termos políticos/econômicos, o país realiza reivindicações aos diversos atores do meio internacional - principalmente às grandes potências - no que se refere à ratificação de Protocolos, Tratados e Acordos que buscam diminuir a emissão de gases poluentes. Contrário aos anseios de Tuvalu, cria-se um discurso conceitual sobre a origem de refugiados ambientais ou apátridas e seu possível enquadramento no corpo jurídico internacional, mas não se debatem possíveis soluções mitigatórias e de adaptação que atenuem o problema específico.Taking into account that global climate change is a reality and that its causes are related to anthropogenic as well as to Earth's own dynamics, we can say that today, after 1989, the resolutions of a group of researchers belonging to the Intergovernmental Panel about Climate Change (IPCC) based scientific data that are used in global political actions at local, regional and global levels, are reshaping and influencing social and economic changes everywhere. The affirmative scientific environmental and climate change are embedded on one political context of global actions characterized by power asymmetry, transversality and transnational of actions. Thus the climate-change phenomenon affecting the island state of Tuvalu and possible solutions for the resulting climatic and political issues go through State action as well as through discussions in international organizations. The principle of citizenship linked to the States is fragmented, since internally, the Tuvalu's State, by losing its territory with rising sea level, cannot guarantee its citizens the right to life and their permanence in its territory. Although politically and economically insignificant, the country claimed the aid of many international actors, specially the great powers to ratify protocols, treaties and agreements aiming at reducing gas emission of polluting gases. However, contrary to Tuvalu's aspirations, it creates a conceptual discourse on the origin of environmental refugees or stateless persons and their possible international legal framework in the body, but did not discuss possible mitigation and adaptation solutions that mitigate the specific problem.
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Olausson, Andreas, and Stefanus Louca. "Reviewing Code Review : Defining and developing High-level ConceptualCode Review at a financial technology company." Thesis, KTH, Lärande, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-273982.
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Code review is a recurring activity at software companies where the source code, orparts of it, undergoes an inspection where the aim is to detect possible errors beforethe code is released for production. A variation of code review that is common today iscalled modern code review and is more lightweight practise than formal code review. Inmodern code review, the developers participate and continuously revise their colleagues’code.At a financial technology company in Stockholm, modern code review is applied. Thecompany has expressed a need to implement a tool that can facilitate the code reviewprocess. One suggestion from the company was to implement high-level conceptual codereview (HCCR), an idea of a tool where code changes are sorted automatically intodifferent commits with a specific message.In order to implement the tool, HCCR needs to be defined and concretised since it haspreviously existed solely as an idea. As a first step of the project, developers’ view ofwhat information is desirable in a commit needed to be examined. The project addressedthe following research questions: What information is desirable and needed by the developers of a medium-sizedcompany, to help them do code reviews in a pull-based environment?– What should the information consist of?– How should the information be presented?To answer these questions, interviews were conducted with software developers at thecompany, together with observations where the developers had to try out a first iterationof HCCR. The first iteration was developed using the company’s guidelines on howdevelopers contribute to code changes together with our company supervisor’s viewson how the tool can work. The interviews were recorded and transcribed, whereafteriia thematic analysis was applied. From the analysis, 13 concepts emerged, which weredivided into five categories. The developers wanted the commits to be atomic, compilableand testable in order to facilitate debugging. The developers also expressed a need toget clear information about both pull-requests (PRs) and commit messages. In theinterviews, a theme emerged that the messages should consist of: what has changed andwhy it has changed. Differences were also observed in the code review process as differentdevelopers use different strategies when reviewing code.Based on the information that emerged from the interviews and observations along withprevious research, a second iteration of HCCR was prepared. The report concludes bydiscussing possible implementations of the tool.Kodgranskning är en vanligt förekommande aktivitet hos mjukvaruföretag där källkoden,eller delar av den, genomgår en granskning för att upptäcka möjliga fel innan kodensläpps till produktion. En variation av kodgranskning som är vanlig idag kallas modernkodgranskning och är en mindre formell kodgranskning där utvecklarna själva är medoch kontinuerligt reviderar sina kollegors kod.Ett finansiellt teknikbolag i Stockholm tillämpar modern kodgranskning. Företagethar uttryckt ett behov av att implementera ett verktyg som kan underlättakodgranskningsprocessen. Ett förslag från företaget var att implementera HCCR, enidé om ett verktyg där kodändringar automatiskt sorteras till olika, så kallade, commits1med ett specifikt meddelande.För att implementera verktyget behöver HCCR definieras och konkretiseras. Som ettförsta steg i projektet behövde vi undersöka utvecklarnas önskvärda information av huren commit bör utformas. Projektet behandlar följande forskningsfrågor: Vilken information är önskvärd och behövs av utvecklarna på ett medelstort företag,för att hjälpa dem att göra kodgranskningar i en pull-based miljö?– Vad ska informationen bestå av?– Hur skall informationen presenteras?För att svara på frågorna gjordes intervjuer med mjukvaruutvecklarna på företagettillsammans med observationer där utvecklarna fick prova på en första iteration avHCCR. Den första iterationen togs fram genom att använda företagets riktlinjer gällandehur utvecklare bidrar med kodändringar tillsammans med åsikter från handledaren påföretaget om hur verktyget kan fungera. Intervjuerna spelades in och transkriberades1När det kommer till ord och uttryck inom Git, (exempelvis commits, pull-request, push, pull) finnsdet ingen standardiserad översättning till svenska. Därför kommer dessa ord skrivas på engelska isammanfattningen.ivvarpå en tematisk analys genomfördes. Från analysen framträdde 13 koncept kringkodgranskning vilka delades in i fem kategorier. Utvecklarna önskade att varje commitskulle vara atomisk, kompilerbar samt testbar för att underlätta felsökning av buggar.Utvecklarna uttryckte också ett behov av att få tydlig information om både PR ochcommit-meddelanden. I intervjuerna framkom det att meddelandena borde bestå av:vad som har ändrats och varför det har ändrats. Det observerades även skillnader ikodgranskningsprocessen då olika utvecklare använder olika strategier när de granskarkod.Baserat på den information som framträdde från intervjuerna och observationernatillsammans med tidigare forskning utarbetades en andra iteration av HCCR. Rapportenavslutas med att diskutera möjliga implementationer av verktyget.
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Baú, João Paulo Trevizan. "Interação de biomoléculas com goethita e sais da água do mar : um estudo de química prebiótica." Universidade Estadual de Londrina. Centro de Ciências Exatas. Programa de Pós-Graduação em Química, 2014. http://www.bibliotecadigital.uel.br/document/?code=vtls000189425.
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As interações de biomoléculas com sais e minerais foram estudadas. A partir destas análises, verificou-se que nos sólidos de adenina obtidos por liofilização quando as soluções foram agitadas com água destilada em meio ácido ou básico, assim como em diferentes águas do mar artificiais, foram observadas mudanças estruturais. Estas mudanças foram devidas à protonação em meio ácido e interação com os sais das águas do mar. Os espectros Raman e FT-IR apresentam o aparecimento de bandas da adenina hipoclorada, assim como bandas devido à interação com os sais da água do mar. Na presença de sais das águas do mar foi observado deslocamentos das bandas dos sais, indicando uma interação com a adenina. Experimentos realizados com os aminoácidos (Gly, Ala) e goethita mostraram que a glicina pode cristalizar com fases diferentes dependendo do método utilizado (A, B e C). Por FT-IR não foi constatado a formação de peptídeos. É importante ressaltar que o mineral não sofreu modificação com os tratamentos, no entanto houve perda de intensidade no sinal de RPE com os métodos, indicando uma possível a organização dos íons Fe(III) e tornando o material totalmente antiferromagnético.Interaction of biomolecules with seawater salts and minerals were studied. From these analyzes, it was found that the solids obtained from the lyophilization of adenine when these solutions were agitated with distilled water at acidic or basic medium as well at different artificial seawaters were observed structural changes. These changes were due to protonation at acidic medium and interaction with cation of the seawaters. The FT-IR and Raman spectra show the appearance of bands of the hydrochloride adenine due to the interaction with the salts of the seawater. In the presence of the salts of the seawater, was observed shifts of the bands, indicating an interaction with the adenine. Experiments carried out with amino acids (Gly, Ala) and goethite showed that the glycine can crystallize with different phases depending on the method used (A, B and C). It was not observed the formation of peptides by FT-IR spectra. It is important to note that the mineral did not suffered modification with treatments. However, there was a loss of intensity in the EPR signal with the methods, indicating a possible organization of the Fe (III) and making a fully antiferromagnetic material.
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Coutinho, Murilo Ameno. "Síntese de ferrihidrita na presença de água do mar artificial e tiocianato de amônio : um experimento de química prebiótica." Universidade Estadual de Londrina. Centro de Ciências Exatas. Programa de Pós-Graduação em Química, 2018. http://www.bibliotecadigital.uel.br/document/?code=vtls000219592.
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A vida na Terra provavelmente surgiu de um grande número de experiências naturais em que várias combinações de moléculas reagiram e recombinaram-se para formar sistemas mais complexo. A química prebiótica estuda como essas reações ocorreram e quais os percussores químicos para a origem da vida. Como os óxidos de ferro são materiais abundantes na crosta terrestre, esses compostos provavelmente devem ter desempenhado um papel importante na origem da vida. O presente trabalho tem como principal objetivo a síntese de ferrihidrita em condições de química prebiótica e posterior caracterização dos óxidos de ferro obtidos. Foi realizado a síntese padrão da ferrihidrita-6-linhas e ao inserirmos na síntese a água do mar artificial e NH4SCN 1:1 Fe3+ foram obtidos além da ferrihidrita-6-linhas, uma mistura de óxidos de ferro (goethita, magnetita e hematita). Destacamos que a água do mar artificial tem sua composição de íons diferente da água do mar atual. Está última possui uma grande concentração de Na+ e Cl-, sendo que a água do mar artificial 4.0 Ga possui uma grande concentração de Mg2+ e SO42- . A ferrihidrita-6-linhas obtida na presença da água do mar artificial, reduziu sua cristalinidade, aumentando assim sua área específica. O SO42- proveniente da água do mar artificial reduziu os valores de pHpcz. A forma como o NH4SCN é adicionado ao meio reacional direciona a síntese para a formação de magnetita, hematita e goethita. Os espectros de infravermelho das amostras apresentaram bandas em 624 cm-1 da ligação Fe-O da ferrihidrita, as bandas em 793cm-1 e 894cm-1(Fe-O) da goethita, 588cm-1 (Fe-O) da magnetita e 430cm-1 (Fe-O) da hematita. As amostras sintetizadas com NH4SCN apresentaram bandas em 2976 cm-1 (N-H) e em 2041 cm-1, evidenciando a efetividade da interação do tiocianato de amônio nos óxidos ferro. As maiores perdas de massa na decomposição térmica correspondem ao processo de desidratação, chegando até 14,9% da massa total da amostra. A partir dos cálculos de PCA da Fluorescência de raio-X foi possível qualificar as porcentagens de cada óxido de ferro nas amostras que apresentaram mistura de óxidos de ferro.Prebiotic chemistry studies the reactions that could have contributed to the origin of life. The Fe is the fourth most abundant element in the Earth's crust, so most likely it must have played an important role in the origin of life. The present work has as main objective the synthesis of ferrihydrite in conditions of prebiotic chemistry and later characterization of the oxides obtained. The standard synthesis of ferrihydrite -6-lines and variations of this was carried out using artificial seawater 4.0 Ga and NH4SCN 1:1 Fe3+. We emphasize that the artificial seawater 4.0 Ga has its composition of cations and anions different from the today's seawater. Today's seawater has high concentration of Na+ and Cl-, and the artificial seawater 4.0 Ga has a high concentration of Mg2+ and SO42-. In addition to the ferrihydrite -6-Lines, a mixture of iron oxides (goethite, magnetite and hematite) were obtained and characterized. The artificial seawater decreased the crystallinity of the ferrihydrite and consequently the surface area of the material was altered. The SO42- was adsorbed onto the materials, decreasing the pHPZC of them. The way the NH4SCN is added to the reactional medium changes the final product of iron oxides obtained. The infrared spectra of the samples showed bands in 624 cm-1 from the Fe-O bond of ferrihydrite and oxide mixture, with bands in 793cm-1 and 894cm-1(Fe-O) of goethite, 588cm-1 (Fe-O) of magnetite and 430cm-1 (Fe-O) of hematite. The samples synthesized with NH4SCN presented bands in 2976 cm-1 (N-H) and in 2041 cm-1, demonstrating the effectiveness of the interaction of ammonium thiocyanate in the iron oxides. The highest mass losses in thermal decomposition correspond to the dehydration process, reaching up to 14.9% of the total sample mass. In the range of 700-900 °C occurred the phase transition to hematite in all samples. From the PCA calculations of X-ray Fluorescence it was possible to qualify the percentages of each iron oxide in the samples that presented mixture of iron oxides.
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Ahumada, Zuaza Luis. "El Teatro Infantil y Juvenil de Carmen Conde." Doctoral thesis, Universidad de Murcia, 2011. http://hdl.handle.net/10803/94519.
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In this research work addresses the question of the status of children´s theater and youth Carmen Conde. In turn is made a thorough study of historical-biographical which meant that literary Spain. Other aspects are addressed as: analysis of dramatic texts child, pedadoficus aspects thereof,subject index, etc. Accompany this study a wide and rich literature on the author and her child and youth drama.En el presente trabajo de investigación se aborda el estado de la cuestión del teatro infantil y juvenil de Carmen Conde. a su vez se realiza un profundo estudio histórico-biográfico de lo que supuso dicho género literario en la producción literaria de la autora y la España del siglo XX. Se abordan otros aspectos como: Análisis de sus textos dramáticos infantiles, aspectos pedagógicos de los mismos, índice temático, etc. Acompaña a dicho estudio una amplia y rica bibliografía sobre la autora y su dramaturgia infantil.
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Dang, Xiaoyu. "An Optimum Detector for Space-Time Trellis Coded Differential MSK." International Foundation for Telemetering, 2007. http://hdl.handle.net/10150/604515.
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ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, NevadaThe accuracy of channel estimation plays a crucial role in the demodulation of data symbols sent across an unknown wireless medium. In this work a new analytical expression for the channel estimation error of a multiple input multiple output (MIMO) system is obtained when the wireless medium is continuously changing in the temporal domain. Numerical examples are provided to illustrate our findings. Space-time (ST) coding using Continuous Phase Modulation (CPM) has spectral advantages relative to linear modulations. In spite of the spectral benefits, Space-Time Trellis Codes (STTC) using the CPM implementation of Minimum Shift Keying (MSK) scheme has inherent inphase and quadrature interference, when the received complex baseband signal is the input into the matchfilter to remove the shaped sinusoid pulses. In this paper a novel optimum transmitting and detecting structure for STTC-MSK is proposed. Treating the Alamouti scheme as an outer code, each STTC MSK waveform frame is immediately followed by the orthogonal conjugate waveform frame at the transmit side. At the receiver first orthogonal wave forming is applied, then a new time-variant yet simple trellis structure of the STTC-MSK signals is developed. This STTC-MSK detector is absolutely guaranteed to be I/Q interference-free and still keeps a smaller computation load compared with STTC-QPSK. Simulations are made over quasi-static AWGN fading channel. It is shown that our detector for ST-MSK has solved the I/Q interference problem and has around 2.8 dB gain compared with the Alamouti Scheme and 3.8 dB gain for bit error rate at 5 X 10^(-3) in a 2 by 1 Multiple Input Single Output system.
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Chami, Malik. "Développement d'un code de transfert radiatif pour le système océan-atmosphère : application au détroit du Pas-de-Calais." Littoral, 1997. http://www.theses.fr/1997DUNK0012.
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L'observation des surfaces océaniques depuis l'espace fournit des informations sur le contenu de l'eau en matières en suspension. Actuellement, les missions spatiales se donnent comme objectif la détermination de la concentration en pigments dans les océans. Cela nécessite la connaissance des mécanismes régissant le transfert du rayonnement solaire dans le système océan-atmosphère. Dans ce contexte, nous avons développé un code de calcul du transfert du rayonnement dans la couche atmosphérique et océanique. La validation de ce code a été conduite à partir d'inter-comparaisons avec des modèles existants et à partir de mesures. L'observation de la surface océanique depuis l'espace se fait à travers l'atmosphère qui est considérée comme un élément perturbateur. On s'emploie donc à corriger le signal des effets atmosphériques. Parmi les composants de l'atmosphère, les aérosols sont les plus difficiles à corriger car ils possèdent une variabilité spatio-temporelle importante ; il est alors préférable de les mesurer localement. Des mesures d'optique atmosphérique ont été réalisées dans le détroit du Pas-de-Calais dans le but de décrire les aérosols présents. L'analyse du rayonnement polarisé a permis d'identifier un mode de petites particules, correctement modélisé par les granulométries de Shettle. À partir de ces modèles, la composante atmosphérique du signal a été éliminée sur des images de l'instrument polder afin de disposer de la luminance à la surface de l'eau. Des mesures d'optique marine ont également été collectées en été et en automne. Les campagnes d'été étaient propices à la télédétection des pigments chlorophylliens alors que celles d'automne favorisaient la caractérisation des particules minérales. L'analyse conjointe des mesures marines et satellitaires a montré qu'une cartographie du milieu en matières en suspension est possible. Par ailleurs, les études de sensibilité effectuées dans ce travail ont montré que l'extraction des sédiments serait envisageable à partir des luminances polariséesThe observation of the sea surface from space proovides informations about the water content in suspended matter. Numerous sensors are launched in order to assess the pigment concentration in the open ocean (case I) as well as in the coastal waters (case II). Therefore, we need to understand the mechanisms which affect the solar beam in the ocean-atmosphere system. We thus developed a radiative transfer code for both atmosphere and coastal layer. The validation of this code was carried out first through an inter-comparison between existing models and second through truth measurements. The observation of the ocean is made throughout the atmosphere wich disturbs the pathways of the solar beam. We thus need to correct the signal for atmospheric effects. Among the components of the atmosphere, aerosols are the most difficult to remove because of their strong variability in time and space ; it is then useful to derive them locally. Atmospheric optical measurements were carried out in the Straits of Dover in 1994 ans 1995 in order to describe the aerosols. The analysis of the polarized radiation enabled to identify a mode of small particles, correctly represented by Shettle and Fenn’s size distribution. The atmospheric contribution to the signal has been removed using Shettleand Fenn’s models on POLDER airborne scenes to get the water leaving radiance. Marine optical measurements were also collected in the water column in summer and autumn. Summer experiments were favorable to remote sense chlorophyll pigments whereas autumn ones concerned mineral particles. The analysis of marine and satellite data showed that a map of suspended matter concentration was possible. Also the theoretical sensitivity studies conducted in this work revealed that the sediment signature could possibly be extracted from the polarized radiance
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Teinturier, Samuel. "Dynamique et stabilité de tourbillons océaniques en interaction avec la cote ou la topographie." Palaiseau, Ecole polytechnique, 2008. https://pastel.archives-ouvertes.fr/tel-00430962.
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Les tourbillons et les écoulements méso-échelles océaniques contribuent de façon importante au transport de masses d’eau et de chaleur dans l’océan. La compréhension de leurs dynamiques, et de leurs interactions avec la topographie, est primordiale, pour caractériser les échanges thermohalins, le déplacements d’espèces biologiques ou de polluants. En particulier, les courants et tourbillons de surface, situés dans les cent ou deux cents premiers mètres de profondeur, jouent un rôle capital dans les échanges entre la zone côtière et la zone hauturière. Cette thèse porte sur la modélisation expérimentale idéalisée de deux phénomènes pouvant participer activement aux échanges horizontaux et verticaux dans la couche supérieure océanique. Les sillages d’îles peuvent être le lieu d’instabilités fortes dans les zones anticycloniques de l’écoulement. Des expériences ont été réalisées sur la Plateforme Coriolis (LEGI) à Grenoble, pour identifier les régimes dynamiques de ces instabilités. Ce dispositif (13 mètres de diamètre) a permis d’atteindre de faibles rapports d’aspects géométriques, tout en travaillant avec un dispositif couche-mince. Des visualisations avec colorants et des mesures du champ de vitesse horizontal par intercorrélation de particules ont été réalisées, afin d’étudier la sensibilité des instabilités dans les anticyclones pour différentes gammes de nombres de Reynolds et de Rossby. Nous montrons que ces instabilités sont présentes dès la couche limite anticyclonique, autour de l’île. L’autre partie de ce travail concerne la dynamique d’un tourbillon de surface, en interaction avec la côte ou le talus océanique. Des mesures récentes (campagne EGYPT-1) nous ont permis de mesurer la dérive particulière d’un anticyclone de surface le long de la côte libyenne. Cette dérive vers l’est ne peut s’expliquer par la simple prise en compte de l’effet beta ou de l’effet miroir le long de la côte. Des expériences idéalisées sont menées sur la table tournante de l’ENSTA, afin de modéliser de façon simple l’interaction d’une côte ou d’un talus sur la dynamique d’un anticyclone, à la surface d’un dispositif bi-couche. La vitesse de ce tourbillon de surface voit notamment sa dérive doubler lorsqu’il se trouve initialement à la base de la pente, montrant ainsi l’existence d’une rétroaction possible de la couche du fond sur la dynamique de la couche de surface.
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Rabillard, Aurélien. "Interactions magmas-détachements : Du terrain (Mer Egée, Grèce) à l'expérimentation." Thesis, Orléans, 2017. http://www.theses.fr/2017ORLE2061/document.
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Les intrusions magmatiques au sein d’une lithosphère soumise aux contraintes tectoniques sont souvent considérées comme des instabilités thermomécaniques à même de stimuler transitoirement et localement la localisation de la déformation. Dans le but de tester ce modèle et de déterminer les possibles mécanismes gouvernant l’initiation d’une déformation localisée au contact et au sein de corps magmatiques en cours de consolidation, ce travail de thèse se propose de coupler une étude de terrain à une approche expérimentale. Les Cyclades (Mer Égée, Grèce) constituent un domaine de croûte continentale en extension dans lequel se sont mises en place au cœur de cinq dômes métamorphiques extensifs (MCCs) des intrusions magmatiques, elles-mêmes coiffées par des systèmes de détachements. Les diverses campagnes de terrain, combinées aux données de la bibliographie, ont permis de proposer un modèle d’interaction régional dans lequel ces corps magmatiques impactent l’évolution tardive de MCCs cycladiques. Au vu des âges de mise en place des intrusions (15-9 Ma), soit plusieurs millions d’années après le début de l’extension et les premiers stades d’exhumation de roches métamorphiques, le magmatisme dans les Cyclades ne peut être considéré comme un candidat réel pour la genèse de MCCs. Néanmoins, les continuums de la déformation enregistrés en bordure des intrusions (depuis l’état magmatique jusqu’aux conditions ductile/cassant) et les relations géométriques avec les détachements laissent supposer un rôle majeur des complexes magmatiques dans les processus de redistribution et de localisation de la déformation, notamment sur le développement séquentiel de détachements. Les vecteurs de localisation de la déformation au sein de magmas partiellement cristallisés ont été en parallèle recherchés par la voie expérimentale. L’étude du comportement structural de magmas, chimiquement et texturalement proches de systèmes naturels, a permis d’une part de confirmer que la déformation se localise préférentiellement le long d’interfaces à rhéologie contrastée tels aux abords de filons syn-plutoniques. Il est d’autre part montré que la présence initiale d’inhomogénéités texturales (e.g. concentration de cristaux en amas) au sein de magmas moyennement cristallisés peut de manière drastique influencer le degré de localisation de la déformation au cours des stades de refroidissement ultérieursMagma intrusions within the lithosphere are often considered as thermomechanical instabilities capable to locally and transiently stimulate strain localization. With the aim of testing this model and determining possible mechanisms that govern the initiation of localized deformation at the contact and within magmatic bodies, this thesis combine a fieldwork with an experimental approach. The Cyclades (Aegean Sea, Greece) form a highly extended continental domain in which five metamorphic core complexes (MCCs) were intruded by magmatic complexes, themselves capped by detachment systems. All collected structural and kinematic data, combined with previous investigations, converge toward a regional scheme in which magmatic bodies dynamically impacted the late evolution of the Cycladic MCCs. Granitoids were emplaced in relatively short time period (15-9 Ma) while metamorphic domes were largely exhumed after more than 10 Myrs of extension. None of those intrusions thereby proves to be a real candidate for the genesis of MCCs. However, continuums of deformation recorded within granitoids (magmatic to ductile/brittle states) as well as geometrical relationships with detachments suggest a pivotal role of magmatic complexes in redistribution and localization processes of the deformation, with in particular the sequential development of detachments. Precursors of strain localization within partially cristallized magmas have been concurrently deciphered by an experimental study. The investigation of the structural behavior of magmas, chemically and texturally similar to natural systems, corroborates that strain localization is efficiently activated along interfaces with contrasting rheology such as in the vicinity of synplutonic dikes. It has been also shown that the initial presence of textural inhomogeneities (e.g. like clusters) in medium-crystallized magmas can drastically influence the degree of strain localization during subsequent cooling stages
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Cattelan, Vittorio <1989>. "Il monastero di Gabriel Mor nella regione di Tur Abdin come caso simbolo di intolleranza religiosa in Turchia." Master's Degree Thesis, Università Ca' Foscari Venezia, 2015. http://hdl.handle.net/10579/5803.
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Caval, Vincent. "Utilisation des propriétés d'assemblage de virus hétérologues pour l'étude du cycle viral du virus de l'hépatite C." Thesis, Tours, 2012. http://www.theses.fr/2012TOUR3319/document.
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Si la découverte récente de la souche virale JFH1, capable de réaliser un cycle viral complet en culture cellulaire, a permis de mieux caractériser le déroulement de l’infection du virus de l’hépatite C VHC, de nombreux aspects de la biologie du virus demeurent méconnus. Parmi ceux-ci, les mécanismes gouvernant l’encapsidation de l’ARN génomique viral au sein des particules restent à élucider. Cette thèse décrit la mise point d’un système de mobilisation hétérologue permettant l’analyse de l’interaction de la protéine de capside Core avec l’ARN viral. Ce système nous a permis d’identifier les régions de la protéine impliquées dans la liaison au génome viral, tout en autorisant son transfert dans des cellules naïves. Cette approche de mobilisation dépendante de la Core est complétée d’une étude de recrutement hétérologue basée sur la reconnaissance de l’ARN du phage MS2 avec la protéine de manteau Coat. Cette stratégie novatrice permet le recrutement efficace des ARNs marqués tout en autorisant leur localisation cellulaireThe advent of infectious molecular clones of Hepatitis C virus (HCV) has unlocked the understanding of HCV life cycle. However, packaging of the genomic RNA, which is crucial to generate infectious viral particles, remains poorly understood. To study packaging in vivo, we developed a novel heterologous system to evaluate the interactions of HCV Core capside with viral RNA. This system allowed us to pinpoint Core domains involved in RNA binding, and package and transfer HCV RNA into a lentiviral vector. Aside from this Core dependent recruitment, we engineered retoviral vectors to trans-package MS2-tagged RNAs using MS2 Coat protein interaction. This system allowed us to efficiently recruit MS2-tagged replicons into naive cells and offers the opportunity to visualize HCV RNAs in Huh7.5 cells
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Dufraisse-Charmillon, Chloé. "La réécriture du droit social maritime au sein du code des transports." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM1044.
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Le code des transports accueille désormais les règles de droit social maritime. Le gouvernement a été habilité à procéder, en 2010, à une recodification à droit constant de ses dispositions éparses, notamment contenues dans le code du travail et le code du travail maritime. Alors que cette opération devait intervenir sans modification de l’état du droit, une certaine inconstance s’est révélée. La structure de la matière a été bouleversée. Elle démontre une ambivalence : le code des transports est exhibé comme instrument du progrès social, mais il peut également devenir un outil de dérèglementation. D'autant que sa partie réglementaire reste très incomplète. L'articulation du nouveau code avec le code du travail interroge également, notamment sous l'angle des rapports entre le droit commun et le droit spécial. Cette réécriture a, de surcroît, subit l'influence du droit international. L’intégration de la convention du travail maritime de l’Organisation internationale du travail a permis de réaffirmer les principes directeurs au fondement de la matière ainsi que la spécificité du droit applicable aux gens de mer. Pour autant, ces dynamiques normatives ont des effets paradoxaux car le droit international participe tour à tour à la destruction et à la reconstruction des droits nationaux. Aussi, la réécriture de la matière au sein du code des transports pourrait être annonciatrice d’un alignement du fond du droit social maritime sur les standards internationaux qui, à l'échelle du droit national français, ne sont pas nécessairement plus protecteurs. Ce mouvement du droit s'explique par une rude concurrence internationale propice à l'expression du dumping socialThe transport code now hosts social maritime law rules. The government was empowered to proceed, in 2010, to a recodification on the basis of established law of its disparate provisions, including those contained in both the labour code and the maritime labour code. Although this operation was to take place without changing the rule of law, a certain instability became obvious. The subject matter's structure was dramatically altered. It reveals an ambivalence : the transport code is exhibited as an instrument of social progress, yet it may also become a deregulation tool. To compound matters, its regulatory aspect remains very incomplete. The articulation of the new code with the labour code is equally perplexing, most notably with regard to the relationship between common law and special law. This rewriting has, in addition, undergone the influence of international law. The integration of the International labour organization's maritime labour convention made it possible to reaffirm the foundational guidelines of this topic as well as the specificity of laws applicable to seafarers. Moreover, these normative dynamics have paradoxical effects. In fact, international law contributes alternately to the destruction and reconstruction of national rights. Thus, the rewriting of the topic within the transport code could be the harbinger of an alignment of maritime social legal foundations with international standards, which, when compared with french law, are not necessarily more protective. This legal evolution reflects is due to a ruthless international competition that enables social dumping conditions
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Mehl, Caroline. "La transition ductile-cassant : évolution structurale et rôle des fluides, exemple des Cyclades, Mer Egée." Paris 6, 2006. http://www.theses.fr/2006PA066064.
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Kadi, Nour. "Optimized broadcasting in wireless ad-hoc networks using network coding." Paris 11, 2010. http://www.theses.fr/2010PA112380.
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Le "Codage Réseau" (Network Coding) est une nouvelle technique qui permet aux routeurs de combiner les flux qu'ils reçoivent et à rediriger ces combinaisons vers les différentes routes. Il a été montré que le codage réseau, combinée avec la diffusion sans fil, peut potentiellement améliorer les performances en termes de débit, l'efficacité énergétique et l'utilisation de bande passante. Notre étude commence par l'intégration de codage réseaux avec la technique de relais multipoint (MPR). MPR est un mécanisme de diffusion efficace qui a été utilisé dans de nombreux protocoles sans fil. Nous montrons que la combinaison de deux techniques ensemble peut réduire le nombre de paquets transmis et augmenter le débit. Nous avons réduit la complexité en proposant un système de codage opportuniste qui effectue des opérations de codage sur le corps binaire. Au lieu de combiner les paquets reçus de manière linéaire, nous employons de sommation arithmétique modulo 2. A chaque transmission, un nœud choisit les paquets pour coder en utilisant les informations sur l'état de voisins tente de livrer un nombre maximum de paquets. Pour réduire Le surcoût (overhead), c'est-à-dire la quantité d'information de contrôle échangée, nous proposons un nouveau schéma de codage. Il utilise LT-code (un type de code fontaine) pour éliminer le besoin d'un feedback parfait entre les voisins. Ce système effectue le codage et le décodage avec une complexité logarithmique. Nous optimisons LT-code pour accélérer le processus de décodage. L'optimisation est réalisée en proposant une nouvelle distribution qui sera utilisés durant le processus d'encodage. Cette distribution permet aux nœuds intermédiaires de décoder même si peu de paquets codés sont reçusNetwork coding is a novel technique which attracts the research interest since its emergence in 2000. It was shown that network coding, combined with wireless broadcasting, can potentially improve the performance in term of throughput, energy efficiency and bandwidth utilization. Our study begins with integrating network coding with multipoint relay (MPR) technique. MPR is an efficient broadcast mechanism which has been used in many wireless protocols. We show how combining the two techniques together can reduce the number of transmitted packets and increase the throughput. We further reduce the complexity by proposing an opportunistic coding scheme which performs coding operations on the binary field. Instead of linearly combining packets, we employ arithmetic summing packets in modulo 2, which simply corresponds to XOR the corresponding bits in each packet. These operations are computationally cheap. Using neighbors state information, a node in our scheme chooses packets to encode and transmit at each transmission trying to deliver a maximum number of packets. Therefore, an exchange of the reception information between the neighbors is required. To reduce the overhead of the required feedback, we propose a new coding scheme. It uses LT-code (a type of fountain code) to eliminate the need of a perfect feedback among neighbors. This scheme performs encoding and decoding with a logarithmic complexity. We optimize LT-code to speed up the decoding process. The optimization is achieved by proposing a new degree distribution to be used during the encoding process. This distribution allows intermediate nodes to decode more symbols even when few encoded packets are received
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El, Khoury Victoria Dufer Jean. "Etude de modifications épigénétiques corrélées à l'expression du gène MDR1 et à la texture nucléaire dans des cellules de carcinome pulmonaire H69 sensibles et résistantes à la chimiothérapie." S.n. : S.l, 2006. http://scdurca.univ-reims.fr/exl-doc/GED00000322.pdf.
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Zackrisson, Elin, and Moa Egertz. "”de tycker ja e mer en kulturell grej än en språklig sak” : En kvalitativ studie kring olika former av tvåspråkighet." Thesis, Örebro universitet, Institutionen för humaniora, utbildnings- och samhällsvetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-33944.
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Costa, Joana Ferreira Fournier. "Parque Botânico do Monteiro-Mor, Lisboa: contributo para o seu plano de gestão e de manutenção." Master's thesis, ISA/UL, 2015. http://hdl.handle.net/10400.5/11171.
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Mestrado em Arquitetura Paisagista - Instituto Superior de AgronomiaThe Botanical Park of Monteiro-Mor is the case study discussed throughout this dissertation. Situated in the historic district of Lumiar, in the northern boundary of the city of Lisbon, was built in the eighteenth century by the 3rd marquis of Angeja and covers an area of 11 ha. This work aims to contribute to the preparation of the management and maintenance plan that will preserve, restore and conserve the historical, cultural and natural heritage of this place. The study of the park consists primarily on an extensive literature review that results in the historical framework of the park over the eighteenth, nineteenth and twentieth centuries. It is essential to the understanding of this place, its origins and its evolution over the centuries that went through to the present. Then is performed a review of all its components, from the characterization of the biophysical factors that are intrinsic to him, lifting each of the structures that compose it, analyzing their needs and capabilities in order to perform an intervention proposal that aims at the development and promotion of the park, with the main objective and concern to safeguard the integrity and authenticity of this historic garden and cultural landscape
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El, Khoury Victoria. "Etude de modifications épigénétiques corrélées à l'expression du gène MDR1 et à la texture nucléaire dans des cellules de carcinome pulmonaire H69 sensibles et résistantes à la chimiothérapie." Reims, 2006. http://www.theses.fr/2006REIMP203.
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La @résistance aux anticancéreux résulte souvent de l'expression de la P-gp, une protéine à efflux codée par le gène MDR1 dont les mécanismes de régulation sont encore mal connus. Au cours de ce travail l'effet de modifications épigénétiques sur le phénotype nucléaire et l'expression du gène MDR1 a été analysé dans des cellules de carcinome pulmonaire sensibles H69WT et résistantes à la chimiothérapie H69VP. Différentes techniques ont été développées pour étudier la texture de la chromatine (cytométrie par analyse d'images), le cycle cellulaire (cytométrie en flux), les modifications post-traductionnelles des histones (western blot, AUT-PAGE) et les mécanismes de régulation du gène MDR1 (RT-PCR en temps réel, ChIP, MSP, COBRA). Il apparaît que les cellules H69VP surexprimant le gène MDR1 présentent, comparativement à leurs homologues sensibles H69WT, des altérations texturales nucléaires correspondant à un aspect " décondensé " de la chromatine. L'inhibition des histones désacétylases par la trichostatine A (TSA) modifie la supra-organisation de la chromatine dont la texture manifeste alors une décondensation progressive dans les cellules sensibles et transitoire dans les cellules résistantes. Ces modifications de la structure chromatinienne semblent refléter les variations du taux d'acétylation des histones H3 localisées au niveau du promoteur MDR1. La TSA induit une surexpression du gène MDR1 dans les cellules H69WT et une diminution de son expression dans les cellules H69VP. Cette régulation apparaît de nature transcriptionnelle et n'est pas liée à une modification de la stabilité de l'ARNm MDR1. L'inhibition de la synthèse protéique de novo réduit mais ne supprime pas l'effet de la TSA sur l'expression du gène MDR1. Ces résultats suggèrent que la TSA modifie l'expression et la fixation à l'ADN d'un ou plusieurs facteurs de transcription impliqués dans la régulation de ce gène de résistance. D'autre part, la modulation différentielle de l'expression du gène MDR1 par la TSA ne correspond pas à une différence de méthylation basale du promoteur MDR1, ni à des variations de l'état de méthylation de ce promoteur au cours du traitement par la TSA. Toutefois, la TSA modifie le profil épigénétique du promoteur MDR1 au niveau duquel elle induit une hyperacétylation des histones H3 et H4, progressive dans les cellules H69WT et transitoire pour les histones H3 dans les cellules H69VP. Enfin, malgré ses effets inverses sur l'expression du gène MDR1 dans les deux lignées cellulaires, la TSA augmente le recrutement du facteur co-activateur PCAF au niveau du promoteur de ce gène. Nos résultats suggèrent l'intérêt que pourraient présenter les inhibiteurs des HDACs dans le traitement des cancers multi-résistants@Multidrug resistance often results from the expression of P-gp, an efflux pump encoded by the MDR1 gene. However molecular mechanisms that regulate MDR1 gene remain poorly understood. This study examined the consequences of epigenetic modifications on nuclear phenotype and MDR1 gene expression in lung carcinoma cell lines sensitive (H69WT) and resistant to chemotherapy (H69VP). H69VP resistant cells overexpressing MDR1 gene display nuclear texture alterations, as compared with H69WT sensitive cells, underlining a more uniform distribution of chromatin. Treatment with trichostatin A (TSA), a histone deacetylase inhibitor, induces a progressive and transient chromatin decondensation in sensitive and resistant cells respectively. These modifications seem to reflect variations of H3 acetylation levels on the MDR1 promoter. TSA up-regulates MDR1 gene expression in H69WT cells and down-regulates its expression in H69VP cells through a transcription mechanism without affecting MDR1 mRNA stability and independently of MDR1 promoter methylation and PCAF recruitment to the MDR1 inverted CCAAT box. Translation inhibition reduces these modulations without suppressing them, suggesting that TSA modifies the expression and DNA binding of transcription factors implicated in the regulation of MDR1 gene. These findings indicate that HDAC inhibitors may represent potential anticancer drugs in multidrug resistant tumors
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Gerardin, Delphine. "Développement de méthodes et d’outils numériques pour l’étude de la sûreté du réacteur à sels fondus MSFR." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAI068/document.
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Les travaux réalisés pendant cette thèse portent sur l’étude de la sûreté du Molten Salt Fast Reactor (MSFR) et incluent à la fois des méthodes d’analyse de risques et des calculs déterministes de sûreté et de design. Ce travail s’inscrit dans le cadre du projet européen SAMOFAR.Le MSFR est un réacteur régénérateur à spectre neutronique rapide qui fonctionne en cycle thorium dans sa configuration de référence, établie en début du projet SAMOFAR. Il a été sélectionné par le Forum International Génération IV pour son potentiel prometteur. Comme tout réacteur nucléaire de quatrième génération, il doit répondre à différentes contraintes dont une sûreté optimale. Celle-ci doit être étudiée dès le stade de conception afin d’être intégrée au design lors de sa définition plutôt qu’ajoutée a posteriori. En raison de ses spécificités, en particulier l’état liquide du combustible, et du stade préliminaire de son design, l’analyse de sûreté du MSFR nécessite l’utilisation de méthodologies d’analyse de sûreté adaptées et technologiquement neutres. Dans cette thèse, une telle méthodologie a été développée et une première application au MSFR réalisée. Elle a notamment permis d’identifier les évènements initiateurs d’accident de ce réacteur et d’élaborer une liste resserrée d’évènements à traiter dans la suite de l’analyse de sûreté.D’autre part, un nouveau code système a été développé pour les études de sûreté. Il est basé sur la diffusion neutronique, prend en compte le transport des précurseurs de neutrons retardés et la puissance résiduelle du combustible. Il a été utilisé pour simuler les transitoires associés à certains des évènements initiateurs et évaluer leurs conséquences pour définir, par la suite, des systèmes de protection adaptés. Ce travail a confirmé l’importance d’un dispositif spécifique au MSFR, le système de vidange d’urgence, permettant de vidanger le combustible en cas d’accident en cœur. Des études paramétriques ont été menées afin de dimensionner ce système avec pour objectif d'assurer l’évacuation de la chaleur résiduelle du combustible et sa sous-criticité en toutes circonstances.Enfin, une première ébauche de l’architecture de sûreté du réacteur a été proposée incluant l’identification des systèmes de protection et la définition des barrières de confinement. Les études de sûreté ont permis de faire des retours sur le design initialement défini. Ils incluent l’ajout de composants, des propositions de design alternatifs, et soulignent les manques de connaissances sur certains phénomènes ou procédures. L’analyse de sûreté réalisée remplit ainsi son objectif principal : guider le design du réacteur dès sa conception afin d’en améliorer la sûretéThis PhD thesis focuses on the study of the Molten Salt Fast Reactor (MSFR) safety. It includes risk analysis methods and deterministic computations for the safety and the design of the reactor. This work was performed in the frame of the SAMOFAR European project.The MSFR is an is-breeder reactor with a fast neutron spectrum. In its reference configuration, defined at the beginning of the SAMOFAR project, it works with the thorium fuel cycle. The MSFR was selected by the Generation IV international forum for its promising features. As any fourth-generation reactor, it must fulfill several objectives including an improved safety. Thus, safety studies should be performed from the early design phases to achieve a safety that is built-in the design rather than added-on. Because of the unique characteristics of the MSFR, including a liquid circulating fuel, and its preliminary design phase, the safety assessment of the reactor should rely on adapted and technological neutral methodologies. In this PhD, such a methodology was developed and a first application to the MSFR was carried on. It allowed to identify the initiating events of the reactor and to elaborate a restricted list of events to be studied in the next steps of the safety analysis.Furthermore, a new code system was developed for the safety studies. It is based on neutronic diffusion and takes into account the movement of the delayed neutrons precursors and the production of the residual heat in the fuel. It was used to simulate the transients associated to some of the identified initiating events with the objective to evaluate their consequences and the need for adequate protection systems. This work confirmed the importance of a device that is specific to the MSFR: the emergency draining system (EDS). It allows to drain the fuel in case of accident in the core. Parametric studies were then carried on for the sizing of the EDS with the objective to ensure the evacuation of the residual heat and the sub-criticality of the system under any circumstances.Finally, a first version of the safety architecture was proposed with the identification of the protection systems and the definition of the confinement barriers. Thanks to the safety studies, feedbacks on the initial design were made to enhance the safety the reactor. They include the addition of new components, the modification of some systems and they highlight the lack of knowledge on some phenomena or procedure. In that respect, the safety analysis fulfil its main objective: to influence the design of the reactor since its conception in order to improve its safety
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FERNANDES-VANDERLEI, LAZARO. "Etude geochimique des sediments marins actuels d'une cote a plateau continental etroit : exemple des alpes maritimes." Nice, 1987. http://www.theses.fr/1987NICE4120.
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On etudie les sediments recents de l'interface dans la baie des anges, la baie de villefranche-sur-mer et dans la reserve sous-marine du larvotto au large de monaco, afin de mettre en evidence les relations existant entre les processus diagenetiques et lithologiques d'une part et les proprietes physico-chimiques des sediments d'autre part. On observe en particulier la qualite de la matiere organique presente dans l'eau et les sediments ainsi que les relations entre m. O. Ou ses produits de desintegration et les metaux-traces. On analyse les variations spatio-temporelles des teneurs en sels nutritifs et en metaux-traces, leur differenciation en fonction des conditions d'oxydo-reduction. On determine les facteurs dominants controlant les processus geochimiques
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Tirler, Günter, and Josef Leydold. "Automatic Nonuniform Random Variate Generation in R." Department of Statistics and Mathematics, Abt. f. Angewandte Statistik u. Datenverarbeitung, WU Vienna University of Economics and Business, 2003. http://epub.wu.ac.at/382/1/document.pdf.
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Random variate genration is an important tool in statistical computing. Many programms for simulation or statistical computing (e.g. R) provide a collection of random variate generators for many standard distributions. However, as statistical modeling has become more sophisticated there is demand for larger classes of distributions. Adding generators for newly required distribution seems not to be the solution to this problem. Instead so called automatic (or black-box) methods have been developed in the last decade for sampling from fairly large classes of distributions with a single piece of code. For such algorithms a data about the distributions must be given; typically the density function (or probability mass function), and (maybe) the (approximate) location of the mode. In this contribution we show how such algorithms work and suggest an interface for R as an example of a statistical library. (author's abstract)Series: Preprint Series / Department of Applied Statistics and Data Processing
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Robert, Samuel. "La vue sur mer et l'urbanisation du littoral : approche géographique et cartographique sur la Cote d'Azur et la Riviera du Ponant." Nice, 2009. https://tel.archives-ouvertes.fr/tel-00442279.
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Cette thèse s’intéresse aux interactions urbanisation – paysage pour comprendre et anticiper les dynamiques du territoire en zone littorale. Depuis plusieurs décennies, les côtes européennes et méditerranéennes sont gagnées par l’artificialisation produite par l’économie résidentielle et touristique. La question du rôle du paysage dans les causes de cette urbanisation, mais aussi dans sa possible régulation, se pose donc avec intérêt. Dans ce contexte, l’étude de la vue sur la mer, quintessence du paysage littoral, apparaît essentielle. L’hypothèse de son influence sur l’urbanisation et, simultanément, celle de l’intérêt d’une connaissance géographique de la visibilité de la mer pour aider à la gestion de l’espace côtier est donc formulée. Pour démontrer l’effet de la vue sur mer sur l’urbanisation du littoral, la thèse propose une méthode de cartographie des espaces soumis à la vue sur mer et s’appuie sur l’étude de la relation spatiale entre visibilité de la mer et occupation du sol. La démonstration est réalisée sur deux territoires littoraux méditerranéens, dont le développement territorial doit beaucoup aux données du paysage : la Côte d’Azur, en France, et la Riviera du Ponant, en Italie. La démarche est menée à deux échelles et à plusieurs niveaux d’analyse de l’espace géographique, avec les outils et les méthodes de traitement de l’information à référence spatiale (le SIG est au cœur du dispositif). Une fois validée, elle est mise à profit pour étayer l’idée que la connaissance de la vue sur mer peut être instaurée en outil urbanistique. Ceci consiste en une expérimentation menée en partenariat avec une commune côtière des Alpes-MaritimesThis thesis deals with the interactions between urbanization and visual landscape, in order to understand and anticipate territorial dynamics in coastal areas. For many decades, European and Mediterranean coasts have been being subjected to urban sprawl, resulting from tourism and residential economy. The issue of visual landscape amenities as a factor of urban sprawl as well as a potential tool of regulation therefore constitutes a crucial perspective. In this context, studying sea views, a major component of coastal landscapes, seems to be a key element. Consequently, it comes to formulate the hypothesis of the sea visibility influence on urban sprawl in coastal areas and simultaneously, of the relevance of geographical knowledge of sea visibility in coastal management. In order to demonstrate the impact of sea visibility on coastal urbanized areas, this study proposes in a first time, a methodology to map coastal areas offering sea views and secondly, a spatial analysis of the interactions between sea visibility and land cover. The study focuses on two Mediterranean coastal zones, which territorial development is strongly related to landscape characteristics : the French Riviera, in Southern France, and the West Ligurian Riviera, in North-West Italy. The analysis handles two different scales and various geographical levels, using geographical information tools and methods (GIS is at the heart of the process). Once this approach validated, it is relevant to support the idea of sea visibility mapping as a tool in land planning. An experiment has been realized in collaboration with one coastal municipality of the Alpes-Maritimes province (France)
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Kashtan, Nadav. "La cote septentrionale de la palestine de 332 a. C. A 70 p. C. : les villes, le littoral et la mer." Université Marc Bloch (Strasbourg) (1971-2008), 1989. http://www.theses.fr/1989STR20022.
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La cote septentrionale de la palestine constituait a l'epoque hellenistique et romaine une entite bien definie que nous proposons d'appeler "cote phenicopalestinienne". Cette appellation met en relief le trait essentiel de la region, a savoir que son histoire et son identite culturelle ont ete profondement marquees par l'heritage phenicien. Les sources archeologiques et litteraires, sur lesquelles repose cette recherche, permettent de degager la diversite des rapports entre les trois composantes successivement etudiees: les sites, le littoral et la mer. Les sites coties comprennent plusieurs cites, dont akko-ptolemais, veritable metropole maritime, dora, leurs dependances, ainsi que la chaine du carmel. L'ensemble du littoral est considere a travers sa position geographique, son histoire politique et son economie, combinant des activites continentales et maritimes. La mediterranee a exercee une influence determinante dans l'ouverture de la region sur le monde exterieur; son impact sur les mentalites a contribue au developpement d'un syncretisme religieux et culturel particulier a cette cote phenico-palestinienneDuring the hellenistic and roman periods, the northern coast of palestine was a well-defined entity that we propose to call "the phoenico-palestinian coast". This appellation brigs out the essential feature of the region, namely the fact that its history and cultural identity were deeply imprinted with the phoenician heritage. From the archaeological and literary sources, on which this study mostly rests, one can derive an idea of the diverse relations between the three elements successively examined: the sites, the littoral itself and the sea. The coastal sites include several cities amongst which akko-ptolemais, a real maritime metropolis, dora, their smaller dependencies, as well as the carmel range. The littoral is considered in the light of its geographical position, its political history and its economy that combined continental and maritime activities. The mediterranean exerted a decisive influence by providing the region with an opening on to the outside world; its impact on the mentality of the population contributes to the development of a religious and cultural syncretism, typical of the phoenico-palestinian coast
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GUERRIERO, Paola. "Studio del potenziale terapeutico del miR-199a-3p come agente di profilassi e anti-tumorale in modelli pre-clinici di epatocarcinoma." Doctoral thesis, Università degli studi di Ferrara, 2019. http://hdl.handle.net/11392/2487889.
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L’epatocarcinoma cellulare (HCC) è la seconda causa di morte per cancro al mondo. La prognosi sfavorevole è legata a diagnosi spesso tardive ed a strumenti terapeutici in gran parte inefficaci negli stadi avanzati.
Negli studi presentati in questa tesi abbiamo saggiato gli effetti anti-tumorali di molecole analoghe al miR-199a-3p, un microRNA (miRNA) sotto-espresso nella maggior parte dei casi di HCC rispetto al tessuto epatico circostante la neoplasia.
Lo studio è stato svolto impiegando il modello murino TG221, un topo transgenico predisposto allo sviluppo di tumori epatici, usando due diverse condizioni sperimentali: (1) terapia anti-tumorale contro tumori “avanzati” indotti tramite il carcinogeno DEN; (2) prevenzione di comparsa di lesioni maligne in topi esposti all’epatotossina CCl4.
Per lo svolgimento delle analisi sul secondo aspetto, abbiamo dimostrato in questo studio che il trattamento con CCl4 del topo TG221 è in grado di riprodurre le diverse fasi (fibrosi -> cirrosi -> noduli displastici -> HCC) della storia naturale del HCC.
Nella condizione di HCC “avanzato”, abbiamo dimostrato che il miR-199-3p riduce significativamente la crescita degli HCC, in maniera analoga a Sorafenib usato nello stesso modello. Nella condizione sperimentale di impiego del miR-199a-3p in topi esposti a CCl4, abbiamo dimostrato che i tumori comparsi in corso di terapia miRNA profilattica erano ridotti in numero e dimensione e soprattutto privi di caratteristiche di malignità.
In entrambe le condizioni, abbiamo determinato che il miR-199-3p induce un abbassamento dei suoi target diretti MTOR e PAK4, proteine coinvolte in molteplici vie che favoriscono la proliferazione e sopravvivenza cellulare.
Esperimenti in vitro, hanno confermato che il ripristino del miR-199a-3p in linee cellulari di HCC induce un significativo effetto pro-apoptotico, agendo anche in questo caso su MTOR e PAK4.
In sintesi, il nostro studio ha dimostrato il potenziale terapeutico del miR-199a-3p in vivo, sia come agente anti-tumorale in HCC avanzato, sia come agente di profilassi. Ciò suggerisce che analoghi di tale miRNA potrebbero rappresentare molecole utili in terapie anti HCC in diverse fasi della sua storia naturale.Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide. Poor prognosis is related to delayed diagnosis and mostly ineffective therapeutic strategies. In this study we analysed the anti-tumoral potential of miR-199a-3p mimic molecules, since miR-199a-3p is downregulated virtually in all HCCs if compared with normal liver tissues. To test miR-199a-3p potential effects, we exploited the transgenic mouse model TG221, which is prone to HCC development, using two different experimental conditions: (1) anti-tumoral effect was tested against DEN-induced advanced tumors; (2) HCC prevention was studied in mice exposed to the hepatotoxin CCl4. Moreover, by CCl4 treatment, the TG221 mouse could recapitulate the different phases of chronic liver disease progression to HCC (fibrosis -> cirrhosis -> dysplastic nodules -> HCC), essential condition to perform our analysis about the second point of this study. We demonstrated that miR-199a-3p could exert an anti-tumoral activity against advanced HCC, by inhibiting tumor growth in a way comparable to that obtained with Sorafenib in TG221-DEN model. In TG221 CCl4-treated mice, we showed a reduction in liver tumor number and dimension for mice that received miR-199a-3p mimic as preventive care and, additionally, none of these nodules had malignant features. In both the experimental protocols, miR-199a-3p increase led to the downregulation of its direct targets MTOR and PAK4, proteins involved in several pathways that promote cellular proliferation and survival. These in vivo results were confirmed by in vitro assays. We demonstrated that restoration of miR-199a-3p in HCC cell lines elicited a significative pro-apoptotic effect by reducing MTOR and PAK4 protein levels. In conclusion, our study illustrates miR-199a-3p therapeutic potential in vivo, both as an anti-tumoral therapy against advanced HCC and as a prophylaxis agent in pre-cancerous conditions, suggesting that miR-199a-3p mimics might be exploited as therapeutic molecules in all the different phases of HCC.
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Karmann, Silvia Kristin [Verfasser]. "Die Ordonnance de la marine und die französische Versicherungspraxis. : Die Entwicklung des Versicherungsvertragsrechts in Frankreich vom Guidon de la mer bis zum Code de commerce. / Silvia Kristin Karmann." Berlin : Duncker & Humblot, 2021. http://d-nb.info/1238492584/34.
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Eriksson, Malin. "Kundorderstyrd tillverkning – Påverkande faktorer, förutsättningar och problem : En övergripande studie om hur små och medelstora företag flyttar kundorderpunkten och går mot mer kundanpassning." Thesis, Högskolan i Skövde, Institutionen för teknik och samhälle, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-5165.
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This study presents a holistic view of which factors small and medium-sized enterprises (SMEs) have to consider, in moving their customer order decoupling point (CODP) further from the customer, thereby becoming more customized. The study also investigate whether SMEs and larger enterprises differ in the strategic questions relating to what influences an enterprise to become more customized, which prerequisites are required and which problems enterprises should anticipate and prepare for. These questions are important, given that strategic change is challenging, and can take considerable time to accomplish; it therefore needs to be based on the right decisions. This study is motivated by the fact that the markets SMEs are selling to tend to become more and more complex and harder to anticipate. Increased globalisation and use of IT and ICT have lead to greater uncertainty in customer demand. At the same time customers have ever more demanding needs and specifications; if these are not met, they will go elsewhere rather than reducing or adapting them. This complexity requires a more customized production and is a way to gain commercial advantages. Customised production includes many benefits such as reduced uncertainty, by producing totally customized products less capital bound is tied up. But meanwhile many challenges such as reduced production efficiency, furthermore flexibility must be increased and higher demands on communications and IT systems are often necessary. The study starts with a wide and thorough theoretical overhaul around the movement of the CODP, but also addresses other parts of the organization to get the all-important big picture. This theoretical work is leading to a work-model which is used in six interviews within SMEs. In order to get a thorough picture, the enterprises that take part in the study are from different line of business and have from 18 to 235 employees. During these interviews, conducted on a single occasion per company, the model and related questions are discussed. Thereby an analysis of the interviews and the theory is done, with the model as the starting-point. The result of this study is a basic model, which SMEs can use as an analytical tool, and a checklist, to facilitate a move towards a make-to-order manufacturing strategy, thereby gaining more flexibility. The study provides a basic generic framework which can be adapted and tailored by the company in question to see which parts are relevant to specific circumstances.
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Service, Bruce Dale. "What Goes Up Must Come Down: The Relationship between the Housing Market Boom and the Subsequent Economic Downturn: Evidence from the MSA Level." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/cmc_theses/1502.
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Using MSA level data, the paper shows, that geographic areas which experienced the largest housing bubble generally suffered a more serious subsequent economic downturn. More specifically, the paper establishes that MSAs with larger declines in housing permits had larger increases in unemployment. There also appears to be strong evidence of a correlation between the magnitude of a housing boom and the timing of the decline in housing permits. MSAs which experienced larger real housing inflation offered early indications of the subsequent Great Recession.
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Carton, Hélène. "Etudes tectoniques en Méditerranée orientale par analyse de données de sismique réflexion : Mer de Marmara (Bassin de ̧Cinarcik) et Marge du Liban." Paris, Institut de physique du globe, 2005. http://www.theses.fr/2005GLOB0019.
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Herbert, Vincent. "La circulation maritime dans le detroit de malacca et ses effets sur la cote occidentale de la peninsule malaise." Nantes, 1999. http://www.theses.fr/1999NANT3006.
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Le detroit de malacca est l'un des passages les plus frequentes au monde. La cote occidentale de la peninsule malaise, en relation avec les faits de circulation maritime de cette region, permet de realiser une analyse geographique d'un espace restreint, mais riche en acteurs et en paysages. L'etude considere le detroit de malacca comme un geosysteme, compose de trois systemes dominants. Le contexte economique regional et international dans lequel se situe ce detroit permet d'expliquer pourquoi et comment le trafic maritime dans cette region s'est developpe de facon spectaculaire. L'analyse du systeme du trafic maritime (qui inclut la circulation transversale) identifie les principaux utilisateurs du detroits. Enfin, le milieu physique est un facteur determinant et limite le choix des routes maritimes. Un premier axe de recherche met en relation la forte frequentation du detroit et ses effets sur les activites de la cote occidentale de la peninsule malaise : (industries portuaires, peche, aquaculture et tourisme). Le second axe se consacre aux moyens mis en oeuvre pour ameliorer la securite de la circulation maritime. Il nous a conduit a la creation d'un indice de risque de pollution marine. Apres avoir compare la part de cette pollution aux pollutions d'origine continentale et littorale, nous avons analyse la politique malaisienne de gestion (structure administrative, choix politiques, relations diplomatiques. . . ), pour savoir si celle-ci repondait aux problemes de pollution. En analysant les effets spatiaux du trafic maritime du detroit de malacca sur la cote occidentale de la peninsule malaise, cette these propose une methode d'analyse geographique applicable aux detroits, ou a d'autres espaces maritimes etroitsThe strait of malacca is one of the busiest maritime passage in the world, and the western coast of the malay peninsula is connected to the maritime traffic of this region. Thus it provides a possible way to carry out a geographical analysis of a limited area and yet which is full of various landscapes and actors. The study looks upon the straits of malacca as a geosystem which is made up of three prevailing systems. The strait is situated in a regional and international economic background which can explain why and how the maritime traffic has expanded in such a spectacular way. An analysis of the maritime traffic (which includes the transverse movements) identifies the main users of this strait. Lastly, the physical environment is a determining and restricting factor for the choice of the sea routes. A first research line associates the important traffic of the strait with the effects noticed on the activities of the western coast of the malay peninsula : port industries, fishing, aquafarming and tourism. The second line is dedicated to the means used to improve the maritime traffic security. It has led us to create a rating for the risk of maritime pollution. After the comparison between the share of this pollution and those of continental and coastal origins, we have analysed the malaysian government management policy (administrative structures, political choices, diplomatic relationships. . . ) to see if it corresponded to the pollution issues. By analysing the spatial effects of the strait of malacca maritime traffic on the western coast of the malay peninsula, this thesis intends to give a method of geographical analysis wich can be applied to straits as well as to narrow maritime area
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Albertsson, Robin, and Joakim Hermansson. "LNG träningsmanual för M/T Bit Viking." Thesis, Linnéuniversitetet, Sjöfartshögskolan (SJÖ), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-31440.
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Denna uppsats är gjord på uppdrag av Tarbit Shipping som år 2011 konverterade sin tankbåt M/T Bit Viking från konventionell drift på tjockolja till LNG (Liquefied Natural Gas).Uppdraget som gavs var att upprätta en tränings manual till fartyget då det är ett krav från IMO (International Maritime Organization). Manualen skrevs i 3 st huvuddelar Kategori A, B och C. Kategori A är till för att manskap ombord ska få en kännedom om gasen och säkerhet runt den, Kategori B är skriven till däcksbefäl där det krävs en större kännedom om gasen och Kategori C är till för maskinbefäl. Manualen finns nu ombord på fartyget och på rederi kontoret för utbildning av nypåmönstrad personal och fortlöpande utbildning av ordinarie personal. Manualen är ett resultat på tolkning av IMO´s IGF kod (ANNEX11. RESOLUTION MSC.285(86)) där det står riktlinjer för säkerheten ombord på fartyg med maskiner som drivs på naturgas.This paper has been produced as a result of an assignment set by Tarbit Shipping which 2011converted one of their product tanker ships from M/T Bit Viking its original heavy fuel oil toLNG (Liquefied Natural Gas). The assignment was to establish a training manual to the shipaccording to IMO´s (International Maritime Organization) IGF code. The manual is written inthree main parts Category A, Category B and Category C. Category A is directed at ratingsand cadets and focuses on gas and safety procedures, Category B is directed at deck officersand focuses on gas, whilst Category C is directed at engine officers and, similar to Category Baims at increasing knowledge levels for engineers. The manual is now located onboard theship and at the company’s office for education of new personnel and for continued educationfor personnel onboard. The manual is a result on an interpretation of IMO´s IGF code(ANNEX11. RESOLUTION MSC.285(86)), in which guidelines are laid out for vesselsfueled by natural gas.
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Bouchlaghem, Karim. "Étude expérimentale et numérique de la pollution atmosphérique dans les villes côtières tunisiennes." Brest, 2009. http://www.theses.fr/2009BRES2002.
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Le développement d’une brise de mer matinale engendre l’augmentation de la concentration en O3 et SO2 à Sousse (Tunisie). Le champ du vent change de direction en se renforçant durant ce type de brise. Nous montrons que les émissions de la centrale électrique de la région sont responsables de la dégradation de la qualité de l’air à Sousse. Cependant, le déclenchement d’une brise de mer dans l’après-midi favorise une augmentation rapide et tardive de la concentration de 03. La recirculation de la pollution couplée à la production photochimique contrôlent l’évolution de la concentration de l’ozone dans la région de Sousse. Ce type de brise génère la formation d’un front de brise et de la circulation de retour au sommet de la couche limite atmosphérique. Les relevés de mesures obtenues à partir de stations fixes et mobiles sur les côtes tunisiennes soutenues par des images satellitaires (MODIS et SEAWIFS) ont servi à l’étude de l’évolution saisonnière des principaux polluants atmosphériques. L’augmentation de la concentration en ozone est due au déclenchement tardif de la brise de mer. Quant aux poussières PM10, cette étude montre que l’augmentation de leur concentration a été observée simultanément dans les quatre sites de mesure (Bizerte, Sousse, Sfax et Tunis). Cela nous a permis de mettre en évidence l’implication des poussières Sahariennes. L’évolution de la concentration des polluants primaires (NO, NO2 et SO2) dépend de la dynamique des masses d’air et des transformations photochimiques saisonnières. Afin de valider ces résultats expérimentaux, nous avons mené une étude numérique à l’aide du code FLUENT permettant de modéliser le phénomène de dispersion d’un polluant en présence d’un écoulement tridimensionnel. Les résultats du modèle sont en bon accord avec les mesures expérimentales. Nous avons ainsi pu mettre en évidence le comportement tridimensionnel des polluants et leur contribution à l’augmentation de la concentration en surfaceThe development of a morning sea breeze triggers the increase of O3 and SO2 concentrations in Sousse (Tunisia). The wind field changes its direction anticlockwise getting even stronger during the sea breeze. We have shown that during this sea breeze type, the power plant emissions are responsible for harming the air quality in the region. The launching of the afternoon sea breeze favours a late rapid increase of O3 concentration. The recirculation of pollutants coupled with the photochemical production control the variation of O3 concentration in Sousse region. This breeze type generates the front breeze and the retum flow circulation at the summit of the atmospheric boundary layer. The experimental measurements obtained from a fixed and mobile stations supported by satellite imageries (MODIS and SEAWIFS) have served the study of seasonal evolution of the principal atmospheric pollutants over the Tunisian coasts. The obtained results show that the evolution of O3 concentration is due to the late breeze setting. As far as dust is concerned, this study shows that the increase in its concentration bas been observed simultaneously in the four measurement sites (Bizerte, Sousse, Sfax and Tunis). This fact has permitted us to point out the Saharan dust implication. The evolution of the concentration of primary pollutants NO, NO2 and SO2 depends on the movement of the air masses and the photochemical transformation. In order to validate these experimental results, we achieved a numerical study using the FLUENT code, simulating the phenomenon of dispersion of a pollutant in presence of a three dimensional flow. The model results fit with the experimental measurements. We pointed out the 3D behaviour of the pollutants dispersion and their contribution to the increase in their surface concentration
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Bronner, Emilie. "Amélioration des performances des radars HF à ondes de surface par étude d' antenne compacte et filtrage adaptatif appliqué à la réduction du fouillis de mer." Paris 6, 2005. https://tel.archives-ouvertes.fr/tel-00078372.
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Bronner, Emilie. "Amélioration des performances des radars HF à ondes de surface par étude d'antenne compacte et filtrage adaptatif appliqué à la réduction du fouillis de mer." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2005. http://tel.archives-ouvertes.fr/tel-00078372.
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Les radars HF à ondes de surface (HFSWR) trouvent des applications dans la surveillance maritime, l'océanographie ou la détection de cibles. Ils utilisent des ondes HF qui se propagent sur la surface de la mer jusqu'à quelques centaines de km. Néanmoins, ils sont récents et encore peu opérationnels à cause de quelques inconvénients. L'objectif de cette thèse est de résoudre deux de ces inconvénients pour améliorer les performances des HFSWR. Tout d'abord, en réduisant la taille des antennes HF usuelles qui sont beaucoup trop grandes. Pour des raisons pratiques et pour envisager des configurations radars embarquées, il est nécessaire de créer une antenne HF compacte pouvant répondre aux cahier des charges du HFSWR. Deuxième préoccupation, les ondes HF et les vagues interagissent et créent des échos de mer élevés qui peuvent masquer des échos de cibles éventuelles. Le second objectif de cette thèse est donc de réduire ces échos marins gênants par une méthode de filtrage adaptatif.
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Konstantinidis, Ioannis. "Le cadre institutionnel de la convention des Nations Unies sur le droit de la mer en quête de son avenir." Thesis, Paris 1, 2016. http://www.theses.fr/2016PA01D001.
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Fruit de négociations longues et ardues, la Convention des Nations Unies sur le droit de la mer signée en 1982 est sans doute l’un des traités multilatéraux les plus réussis sur le plan international. Pierre angulaire de la Convention, l’attribution du statut de « patrimoine commun de l’humanité » aux fonds marins et leur sous-sol situés au-delà des limites de la juridiction nationale ainsi qu’à leurs ressources a constitué une innovation majeure dans le domaine du droit international. Le succès de la Convention tient notamment au fait qu’elle a établi un cadre institutionnel sans précédent chargé de la mise en œuvre de la Convention et incarné par trois institutions : l’Autorité internationale des fonds marins, la Commission des limites du plateau continental et le Tribunal international du droit de la mer. Dotées de statuts juridiques divers et de compétences différentes, ces institutions fonctionnent depuis l’entrée en vigueur de la Convention en 1994. Vingt-et-un ans après sa fondation, il convient d’examiner ce cadre institutionnel dans son ensemble et d’évaluer sa mise en œuvre pour mieux comprendre le rôle complémentaire des institutions. Cette étude porte un regard critique sur la genèse, la nature, le fonctionnement et la pratique des institutions, et s’attache à les considérer dans leur interaction et leur interdépendance. Identifier les insuffisances institutionnelles et interinstitutionnelles, ainsi que les défis auxquels les institutions sont confrontées est un préalable indispensable à la recherche de solutions efficaces et viables pour surmonter les difficultés rencontrées, à la mise en œuvre harmonieuse de la Convention et à la concrétisation du concept fondamental de patrimoine commun de l’humanité. Dans cette perspective, l’importance du Tribunal dans son rôle de garant de l’intégrité de la Convention et le pouvoir créateur du juge international face aux lacunes conventionnelles méritent une attention toute particulièreThe result of protracted and arduous negotiations, the United Nations Convention on the Law of the Seasigned in 1982 is undoubtedly one of the most successful multilateral treaties at the international level. The principle of the common heritage of mankind, represented by the seabed, ocean floor and subsoil and their resources beyond the limits of national jurisdiction, is the cornerstone of the Convention and constituted a major innovation in international law. The success of the Convention lies, in particular, in the establishment of an unprecedented institutional framework, which is incarnated by three institutions: the International Seabed Authority, the Commission on the Limits of the Continental Shelf and the International Tribunal for the Law of the Sea. These institutions of diverse legal status are vested with different functions and have been in operation since the entry into force of the Convention in 1994. Twentyone years following its establishment, it is necessary to review this institutional framework as a whole and to assess its implementation in order to better understand the complementary role of the institutions. This study critically examines the genesis, the nature, the functioning and the practice of the institutions throughtheir interaction and their interdependence. Identifying institutional and inter-institutional weaknesses, and the challenges that the institutions face is an indispensable prerequisite for ensuring effective and viablesolutions, the harmonious implementation of the Convention and for giving substance to the principle ofthe common heritage of mankind. In this context, the role of the Tribunal as the guarantor of the integrityof the Convention and the creative power of the international judge merit special attention
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Canali, Andrea. "Analisi delle criticità e delle potenzialità di un depuratore a tecnologia MBR tramite modellazione WEST: scenario attuale e upgrade del depuratore, gestito da HERA, a servizio del Comune di Castel Guelfo (BO)." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
Find full textAbstract:
Il seguente elaborato vuole rappresentare il primo studio pubblico di modellazione tramite il software WEST® di un impianto di depurazione delle acque reflue realmente esistente utilizzante tecnologia di depurazione con membrane da ultrafiltrazione (MBR), con anche un’ analisi degli upgrade impiantistici migliori per diminuire i costi operativi e migliorare le uscite degli inquinanti , particolarmente dei nitrati. Lo studio è stato effettuato sull’ impianto sito del comune di Castel Guelfo, gestito da Hera, che serve una zona con forte impatto di attività produttive. Le criticità di questo impianto sono legate all’ estrema variabilità degli ingressi da rete fognaria e alla presenza di correnti parassite di natura irrigua, che creano squilibri nei rapporti tra i vari carichi organici. Dopo un introduzione sulla tecnologia MBR , su suoi principali aspetti gestionali, quali la gestione del ricircolo e delle portate eccedenti, e una descrizione delle equazioni che regolano il suo dimensionamento, è stata fatta un’ analisi dell’ impianto studiato, sia dal punto di vista della verifica del dimensionamento sia come analisi dei carichi entranti sul periodo gennaio-settembre 2018, costruendo poi il modello WEST dell’ impianto MBR, con implementazione dei vari processi discontinui in esso presenti, quali DO, ricircolo, portata d’aria e flusso delle membrane. Successivamente è stato studiato l’upgrade che prevedeva la totale trasformazione delle vasche di ossidazione in vasche di denitrificazione, con anche analisi delle migliori condizioni operative. Si è poi provveduto a verificare l’andamento con una parziale trasformazione delle vasche di ossidazione, con implementazione di un controllore dell’ ammoniaca uscente e con la diminuzione del valore di TSS in vasca MBR, ottenendo il migliore upgrade possibile, senza prevedere nuove costruzioni.
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Butaeye, Étienne. "La maîtrise des compétences de l'équipage du navire marchand pour la prévention des dommages : une prérogative de l'armateur." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0169/document.
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La complexité de la conduite du navire marchand impose aux opérateurs d’avoir de nombreuses connaissances dans différents domaines. La standardisation de la formation maritime au niveau international par la convention STCW est un élément qui participe à garantir de leur capacité à conduire l’expédition maritime. Mais il n’est pas suffisant. L’armateur est l’acteur clé dans ce domaine. Son investissement dans le maintien et le développement des connaissances techniques, dans l’encadrement de l’exploitation du navire et dans la mise en place d’une stratégie de gestion des facteurs humains adaptée, est déterminant pour maîtriser les compétences de son personnel navigant et prévenir les dommages qui résulteront de leurs erreurs. Il est très intéressant de constater que le droit maritime tient compte de cet investissement pour déterminer le régime de responsabilité civile auquel l’armateur sera soumis lorsqu’il devra répondre des actes dommageables de ses préposés. Son implication dans la mise en place de stratégies de gestion humaine adaptées lui permettra d’accéder à de larges aménagements ou exonérations de responsabilité. Le régime très protecteur dont il bénéficie sera en revanche progressivement levé, en fonction des manquements personnels retenus à son encontre. Le droit maritime participe donc, d’une certaine manière, à responsabiliser les armateurs. La réalité est en fait plus nuancée car les difficultés pour lever ce régime spécifique sont nombreuses. Les protections qui lui sont accordées pourront alors apparaître comme un facteur démobilisant dans l’objectif de maîtriser l’élément humain, pourtant essentiel pour la sécurité maritimeThe complexity of operating a vessel requires that crew members have in depth knowledge in a wide variety of areas. The International maritime training that has been standardized by the STCW convention is one of the elements that helps to guarantee their ability to make the maritime expedition a success. But it is not enough. The shipowner is the key actor in this area. His personal investment to maintain and develop technical knowledge, to supervise vessel operation and to implement an appropriate human factor strategy, is crucial for controlling the competencies of his crew to prevent potential damages that could result from human errors. It is very interesting to see that maritime law considers this investment in determining the civil liability regime to which shipowners will be subject for the damages caused by negligence of his crew. His involvement in implementing efficient human strategies will allow him to benefit from wide exemptions or limitation of liability. The very protective civil liability regime he enjoys will nevertheless be lifted, at least partially, for his own omissions that contribute to the damage. Maritime law therefore encourages, in a certain way, shipowners to get involved in vessel crewing. The reality is actually more nuanced because the difficulties to lift this specific regime are various. The protections that are granted to a shipowner will then appear to be a demobilizing factor in controlling the human element, which is essential for maritime safety
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Pavlíček, Michal. "Přístupy k zajištění jaderné bezpečnosti u reaktorů 3. generace." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229286.
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The main target of the master´s thesis is reviewing the generation III nuclear reactors in term of the nuclear safety. At first we have to learn some theory of the nuclear safety in order to understand safety systems of the generation III nuclear reactors. Therefore the thesis is divided into two parts. Legislative and technical approaches to nuclear safety are mentioned in the first part. Regulatory bodies, whose task is to supervise nuclear safety in the nuclear power plants, belongs to the legislative approaches. There are defined terms such as defence in depth, redundancy, diversity, etc. There are mentioned methods to assessing nuclear safety – deterministic and probabilistic methods, especially probabilistic methods, for which a simple example is provided. There are also mentioned active and passive safety systems and their significance for nuclear safety and inherent safety too. There is an example of the function of the active and passive safety systems of the EDU nuclear power plant in conclusion of this issue. The second part deals with description of the selected nuclear reactors in context of the construction of the new units of nuclear power plant in Temelín. The nuclear reactors from companies, which applied for the public tender opened by ČEZ, a. s., for the construction of the ETE 3+4. Thus, the nuclear reactor MIR-1200 by ATOMSTROYEXPORT (Russian Federation), the nuclear reactor AP1000 by WESTINGHOUSE (USA) and the nuclear reactor EPR by AREVA (France) are taken into account . Comparison of the generation II and these generation III+ nuclear reactors necessarily belongs to this master´s thesis. These the generation III+ nuclear reactors are compared with the nuclear reactor VVER 440 (EDU) and in particular with the nuclear reactor VVER 1000, which is operated in the nuclear power plant Temelín. The final chapter contains generally appraisal of the whole problem.
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Čermák, Jiří. "Návrh elektročásti zařízení na máčení a sušení jader pro tvorbu odlitků." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-318169.
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This diploma thesis deals with proposal of electrical equipment for soaking and drying cores for making castings at foundry in a Great Britain. It brings look at system of technical norms ČSN and it compares it with british system of technical norms British standards. The second part of this thesis contains detailed proposal of this equipment, including specification of control system, specification of power supply cables and control cables and particular technological units. The whole project documentation is enclosed as an inseparable attachment of this diploma thesis.
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Birenjith, P. S. "High-rate MSR Codes, Interior-point Regenerating Codes, and Codes with Hierarchical Locality." Thesis, 2017. http://etd.iisc.ac.in/handle/2005/4293.
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Given the breath-taking pace at which the amount of data being generated on a daily basis is growing,
and the keen desire to extract information from this data, there is strong interest within the storage
industry, at finding means to efficiently and reliably store this data. Given that individual storage units
are prone to failure, data pertaining to a single _le is distributed across storage nodes. Such storage
of `Big Data' across a spatially distributed network of nodes, calls for codes than can efficiently handle
the issue of node repair. The need for node repair could arise on account of device failure, need for
a maintenance reboot, or simply because the node is busy serving other demands. A new branch of
coding theory has sprung up in response. Regenerating codes minimize data download during a repair
operation, while codes with locality ensure that local operations suffice for node repair. The present
thesis makes contributions to both regenerating codes as well as codes with locality.
While the reliable storage of data in disks with minimum storage overhead is a well-studied problem,
the problem of node repair is relatively new. From the viewpoint of the storage industry, the cost to
repair a failed node can be measured in two distinct ways: firstly, in terms of the number of surviving
nodes accessed, and secondly, in terms of the amount of data transmitted over the network to ensure
repair of the failed node.
In a regenerating code having parameter set (n; k; d; (_; _);B), and over a _finite _field Fq, a file
consisting of B symbols from Fq is encoded into n_ symbols, and the coded symbols are stored in n
distinct nodes, each node storing _ symbols. The parameter _ is referred to as sub-packetization level.
The entire _le can be recovered from downloading k_ symbols from any set of k nodes. Under the
exact-repair (ER) setting that is of interest here, the contents of a failed node are repaired exactly
from a total of d_ symbols downloaded from any d helper nodes, each helper node transmitting _
symbols. In the alternative setting of functional repair (FR), the contents of the replacement node can
be different from that of the failed node, however, following node repair, the new configuration is still
required to satisfy the data-recovery and node repair properties of a regenerating code. Under the FR
setting, there is a trade-off known as storage-repair-bandwidth (S-RB) trade-off between the values of
_ and d_, that optimize the size of the _le being stored. The two extreme points of the trade-off, one
corresponding to the minimum possible value of _ and the other, to the minimum possible value of d_,
are known as the minimum-storage-regenerating (MSR) and minimum-bandwidth-regenerating (MBR)
points respectively. It has been shown that the extreme points of the ER trade-off coincide with those
of the FR trade-off. However, the characterization of trade-off in the case of ER remains an open and
challenging problem.
High-rate MSR code constructions the _first problem reported in the thesis, is one of designing
exact-repair MSR codes that possess certain additional desirable properties, namely, high rate (i.e., rate
greater than half) and a small value of sub-packetization level _. In the present thesis, we construct a
family of MSR codes for d = (n 1) having a fixed rational rate R = (t 1)=t and a sub-packetization
that is polynomial in k for a fixed rate. In the construction, _ varies with k as _ = O(kt). This was the
first high-rate MSR code construction to have such small value of sub-packetization.
Canonical codes: Regenerating codes for the interior points of the S-RB trade-off the next
pair of results relate to the construction of interior-point regenerating codes. For the parameter set
(n; k; d = k), we first construct as our second result, a class of codes referred to as canonical codes,
having an auxiliary parameter w, with w in the range nk < w < k, these codes operate in the region
between the MSR point and the MBR point, and perform significantly better than operating points
obtained through space-sharing. The canonical code constructed for the case (n; k = n 1; d = n 1),
turn out to achieve an interior point of the FR trade-off, thus characterizing for the first time, an interior
point of the ER trade-off.
Generalized Canonical codes We next build on top of a canonical code having parameters (n; d; d)
and construct codes corresponding to a more general parameter set of the form (n; k < d; d) using
two different approaches. In the first approach, leading to what we refer to as non-canonical codes, an
exponential expansion in field size is needed while the parameters _ and _ remain the same as in the
case of the (n; d; d) code. In the second approach, the value of _ is increased from that of the (n; d; d)
code, but no expansion in field size is needed. The resultant codes are referred to as improved layered
codes. Both approaches lead to codes that perform much better than the space-sharing line.
Outer bounds on the storage-repair-bandwidth trade-off the next set of results presented here
take on the form of two distinct outer bounds for the S-RB trade-off. The first is referred to here as
the repair-matrix bound and the second as the improved Muhajir-Tandon bound. The repair-matrix
bound lies strictly away from the FR trade-off for every parameter (n; k; d), and thus proves that the
ER trade-off is bounded away from the FR trade-off, even when the _le size grows to infinity. This result
solved an open problem in the literature. In conjunction with the improved layered codes constructed
in the thesis and described above, these outer bounds characterize the ER trade-off for the case when
(n; k = 3; d = n 1). This is the first family of parameters for which the ER trade-off is characterized.
Furthermore, for the parameter set (n; k = 4; d = n 1), the operating point of the improved layered
code coincides with the outer bound, characterizing yet another interior point of the S-RB trade-off.
Codes with hierarchical locality the final set of results relate to the second class of codes developed
for efficient node repair, namely, codes with locality. The aim of this class of codes is to reduce the
number of nodes accessed while repairing a failed node. In a code with locality having locality parameter
r, every symbol can be repaired by accessing r other symbols, where r is typically, much smaller than the
dimension k of the code. We introduce in the thesis the notion of hierarchical locality, where the local
codes are of varying locality and possess a hierarchical structure. In the case of two-level hierarchical
locality, for instance, every symbol is protected both by an inner, short-block-length local code, as well
as a middle code of larger block length. The code symbols in the inner code are a subset of the code
symbols in the middle code. We first present the case of codes with two-level hierarchy, derive an upper
bound on the minimum distance and provide optimal code constructions for a wide parameter range.
The minimum-distance bound, and code construction are then generalized for the case of a hierarchical
structure having an arbitrary number of levels.
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Vinayak, R. "On Codes for Private Information Retrieval and Ceph Implementation of a High-Rate Regenerating Code." Thesis, 2017. http://etd.iisc.ac.in/handle/2005/3800.
Full textAbstract:
Error-control codes, which are being extensively used in communication systems, have found themselves very useful in data storage as well during the past decade. This thesis deals with two types of codes for data storage, one pertaining to the issue of privacy and the other to reliability.
In many scenarios, user accessing some critical data from a server would not want the server to learn the identity of data retrieved. This problem, called Private Information Retrieval (PIR) was rst formally introduced by Chor et al and they gave protocols for PIR in the case where multiple copies of the same data is stored in non-communicating servers. The PIR protocols that came up later also followed this replication model. The problem with data replication is the high storage overhead involved, which will lead to large storage costs. Later, Fazeli, Vardy and Yaakobi, came up with the notion of PIR code that enables information-theoretic PIR with low storage overhead. In the rst part of this thesis, construction of PIR codes for certain parameter values is presented. These constructions are based on a variant of conventional Reed-Muller (RM) codes called binary Projective Reed-Muller (PRM) codes. A lower bound on block length of systematic PIR codes is derived and the PRM based PIR codes are shown to be optimal with respect to this bound in some special cases. The codes constructed here have smaller block lengths than the short block length PIR codes known in the literature. The generalized Hamming weights of binary PRM codes are also studied.
Another work described here is the implementation and evaluation of an erasure code called Coupled Layer (CL) code in Ceph distributed storage system. Erasure codes are used in distributed storage to ensure reliability. An additional desirable feature required for codes used in this setting is the ability to handle node repair efficiently. The Minimum Storage Regenerating (MSR) version of CL code downloads optimal amount of data from other nodes during repair of a failed node and even disk reads during this process is optimum, for that storage overhead. The CL-Near-MSR code, which is a variant of CL-MSR, can efficiently handle a restricted set of multiple node failures also. Four example CL codes were evaluated using a 26 node Amazon cluster and performance metrics like network bandwidth, disk read and repair time were measured. Repair time reduction of the order of 3 was observed for one of those codes, in comparison with Reed Solomon code having same parameters. To the best of our knowledge, such large gains in repair performance have never been demonstrated before.
48
Vinayak, R. "On Codes for Private Information Retrieval and Ceph Implementation of a High-Rate Regenerating Code." Thesis, 2017. http://etd.iisc.ernet.in/2005/3800.
Full textAbstract:
Error-control codes, which are being extensively used in communication systems, have found themselves very useful in data storage as well during the past decade. This thesis deals with two types of codes for data storage, one pertaining to the issue of privacy and the other to reliability.
In many scenarios, user accessing some critical data from a server would not want the server to learn the identity of data retrieved. This problem, called Private Information Retrieval (PIR) was rst formally introduced by Chor et al and they gave protocols for PIR in the case where multiple copies of the same data is stored in non-communicating servers. The PIR protocols that came up later also followed this replication model. The problem with data replication is the high storage overhead involved, which will lead to large storage costs. Later, Fazeli, Vardy and Yaakobi, came up with the notion of PIR code that enables information-theoretic PIR with low storage overhead. In the rst part of this thesis, construction of PIR codes for certain parameter values is presented. These constructions are based on a variant of conventional Reed-Muller (RM) codes called binary Projective Reed-Muller (PRM) codes. A lower bound on block length of systematic PIR codes is derived and the PRM based PIR codes are shown to be optimal with respect to this bound in some special cases. The codes constructed here have smaller block lengths than the short block length PIR codes known in the literature. The generalized Hamming weights of binary PRM codes are also studied.
Another work described here is the implementation and evaluation of an erasure code called Coupled Layer (CL) code in Ceph distributed storage system. Erasure codes are used in distributed storage to ensure reliability. An additional desirable feature required for codes used in this setting is the ability to handle node repair efficiently. The Minimum Storage Regenerating (MSR) version of CL code downloads optimal amount of data from other nodes during repair of a failed node and even disk reads during this process is optimum, for that storage overhead. The CL-Near-MSR code, which is a variant of CL-MSR, can efficiently handle a restricted set of multiple node failures also. Four example CL codes were evaluated using a 26 node Amazon cluster and performance metrics like network bandwidth, disk read and repair time were measured. Repair time reduction of the order of 3 was observed for one of those codes, in comparison with Reed Solomon code having same parameters. To the best of our knowledge, such large gains in repair performance have never been demonstrated before.
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Moorthy, Prakash Narayana. "Codes With Locality For Distributed Data Storage." Thesis, 2015. https://etd.iisc.ac.in/handle/2005/2648.
Full textAbstract:
This thesis deals with the problem of code design in the setting of distributed storage systems consisting of multiple storage nodes, storing many different data les. A primary goal in such systems is the efficient repair of a failed node. Regenerating codes and codes with locality are two classes of coding schemes that have recently been proposed in literature to address this goal. While regenerating codes aim to minimize the amount of data-download needed to carry out node repair, codes with locality seek to minimize the number of nodes accessed during node repair. Our focus here is on linear codes with locality, which is a concept originally introduced by Gopalan et al. in the context of recovering from a single node failure. A code-symbol of a linear code C is said to have locality r, if it can be recovered via a linear combination of r other code-symbols of C. The code C is said to have (i) information-symbol locality r, if all of its message symbols have locality r, and (ii) all-symbol locality r, if all the code-symbols have locality r. We make the following three contributions to the area of codes with locality.
Firstly, we extend the notion of locality, in two directions, so as to permit local recovery even in the presence of multiple node failures. In the first direction, we consider codes with \local error correction" in which a code-symbol is protected by a local-error-correcting code having local-minimum-distance 3, and thus allowing local recovery of the code-symbol even in the presence of 2 other code-symbol erasures. In the second direction, we study codes with all-symbol locality that can recover from two erasures via a sequence of two local, parity-check computations. When restricted to the case of all-symbol locality and two erasures, the second approach allows, in general, for design of codes having larger minimum distance than what is possible via the rst approach. Under both approaches, by studying the generalized Hamming weights of the dual codes, we derive tight upper bounds on their respective minimum distances. Optimal code constructions are identified under both approaches, for a class of code parameters. A few interesting corollaries result from this part of our work. Firstly, we obtain a new upper bound on the minimum distance of concatenated codes and secondly, we show how it is always possible to construct the best-possible code (having largest minimum distance) of a given dimension when the code's parity check matrix is partially specified. In a third corollary, we obtain a new upper bound for the minimum distance of codes with all-symbol locality in the single erasure case.
Secondly, we introduce the notion of codes with local regeneration that seek to combine the advantages of both codes with locality as well as regenerating codes. These are vector-alphabet analogues of codes with local error correction in which the local codes themselves are regenerating codes. An upper bound on the minimum distance is derived when the constituent local codes have a certain uniform rank accumulation (URA) property. This property is possessed by both the minimum storage regenerating (MSR) and the minimum bandwidth regenerating (MBR) codes. We provide several optimal constructions of codes with local regeneration, where the local codes are either the MSR or the MBR codes. The discussion here is also extended to the case of general vector-linear codes with locality, in which the local codes do not necessarily have the URA property.
Finally, we evaluate the efficacy of two specific coding solutions, both possessing an inherent double replication of data, in a practical distributed storage setting known as Hadoop. Hadoop is an open-source platform dealing with distributed storage of data in which the primary aim is to perform distributed computation on the stored data via a paradigm known as Map Reduce. Our evaluation shows that while these codes have efficient repair properties, their vector-alphabet-nature can negatively a affect Map Reduce performance, if they are implemented under the current Hadoop architecture. Specifically, we see that under the current architecture, the choice of number processor cores per node and Map-task scheduling algorithm play a major role in determining their performance. The performance evaluation is carried out via a combination of simulations and actual experiments in Hadoop clusters. As a remedy to the problem, we also pro-pose a modified architecture in which one allows erasure coding across blocks belonging to different les. Under the modified architecture, the new coding solutions will not suffer from any Map Reduce performance-loss as seen in the original architecture, while retaining all of their desired repair properties
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Moorthy, Prakash Narayana. "Codes With Locality For Distributed Data Storage." Thesis, 2015. http://hdl.handle.net/2005/2648.
Full textAbstract:
This thesis deals with the problem of code design in the setting of distributed storage systems consisting of multiple storage nodes, storing many different data les. A primary goal in such systems is the efficient repair of a failed node. Regenerating codes and codes with locality are two classes of coding schemes that have recently been proposed in literature to address this goal. While regenerating codes aim to minimize the amount of data-download needed to carry out node repair, codes with locality seek to minimize the number of nodes accessed during node repair. Our focus here is on linear codes with locality, which is a concept originally introduced by Gopalan et al. in the context of recovering from a single node failure. A code-symbol of a linear code C is said to have locality r, if it can be recovered via a linear combination of r other code-symbols of C. The code C is said to have (i) information-symbol locality r, if all of its message symbols have locality r, and (ii) all-symbol locality r, if all the code-symbols have locality r. We make the following three contributions to the area of codes with locality.
Firstly, we extend the notion of locality, in two directions, so as to permit local recovery even in the presence of multiple node failures. In the first direction, we consider codes with \local error correction" in which a code-symbol is protected by a local-error-correcting code having local-minimum-distance 3, and thus allowing local recovery of the code-symbol even in the presence of 2 other code-symbol erasures. In the second direction, we study codes with all-symbol locality that can recover from two erasures via a sequence of two local, parity-check computations. When restricted to the case of all-symbol locality and two erasures, the second approach allows, in general, for design of codes having larger minimum distance than what is possible via the rst approach. Under both approaches, by studying the generalized Hamming weights of the dual codes, we derive tight upper bounds on their respective minimum distances. Optimal code constructions are identified under both approaches, for a class of code parameters. A few interesting corollaries result from this part of our work. Firstly, we obtain a new upper bound on the minimum distance of concatenated codes and secondly, we show how it is always possible to construct the best-possible code (having largest minimum distance) of a given dimension when the code's parity check matrix is partially specified. In a third corollary, we obtain a new upper bound for the minimum distance of codes with all-symbol locality in the single erasure case.
Secondly, we introduce the notion of codes with local regeneration that seek to combine the advantages of both codes with locality as well as regenerating codes. These are vector-alphabet analogues of codes with local error correction in which the local codes themselves are regenerating codes. An upper bound on the minimum distance is derived when the constituent local codes have a certain uniform rank accumulation (URA) property. This property is possessed by both the minimum storage regenerating (MSR) and the minimum bandwidth regenerating (MBR) codes. We provide several optimal constructions of codes with local regeneration, where the local codes are either the MSR or the MBR codes. The discussion here is also extended to the case of general vector-linear codes with locality, in which the local codes do not necessarily have the URA property.
Finally, we evaluate the efficacy of two specific coding solutions, both possessing an inherent double replication of data, in a practical distributed storage setting known as Hadoop. Hadoop is an open-source platform dealing with distributed storage of data in which the primary aim is to perform distributed computation on the stored data via a paradigm known as Map Reduce. Our evaluation shows that while these codes have efficient repair properties, their vector-alphabet-nature can negatively a affect Map Reduce performance, if they are implemented under the current Hadoop architecture. Specifically, we see that under the current architecture, the choice of number processor cores per node and Map-task scheduling algorithm play a major role in determining their performance. The performance evaluation is carried out via a combination of simulations and actual experiments in Hadoop clusters. As a remedy to the problem, we also pro-pose a modified architecture in which one allows erasure coding across blocks belonging to different les. Under the modified architecture, the new coding solutions will not suffer from any Map Reduce performance-loss as seen in the original architecture, while retaining all of their desired repair properties