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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Mobilisations politiques et expertise électorale : la question de la « représentation proportionnelle ». Histoire sociale de la réforme électorale sous la Troisième République / Political mobilization and electoral expertise : the question of proportional representation. Social history of electoral reform in the Third Republic

Marty, Thomas 10 November 2011 (has links)
Au début du vingtième siècle, après deux décennies sans réforme électorale, le mode de scrutin devient un sujet de controverse. Cette étude se propose d’examiner les conditions du choix de la représentation proportionnelle par les membres de la Chambre des députés française ainsi que par d’autres militants. Au-delà de la rééligibilité législative, c’est à travers le changement du mode de scrutin (introduction du scrutin de liste et de la représentation proportionnelle) que le problème de la réélection apparaît sous la Troisième République. Les professeurs de droit constitutionnel, tant à Paris qu’en province, délaissent cette expertise malgré quelques entreprises militantes éparses. Leurs étudiants formulent alors un savoir académique vite enserré par les contraintes récurrentes des jurys de thèse. Nous cherchons à examiner pourquoi et comment le parlement s’est emparé de cette question. Si les conservateurs et les socialistes sont les plus zélés partisans de la représentation proportionnelle, on ne peut en rester au fait que les partis défendent des systèmes qui les favorisent le plus. Notre étude insiste sur la stabilité socio-biographique du recrutement parlementaire plutôt que sur les variations de majorité et donc d’intérêts. Il faut expliquer pourquoi et comment ce fut le débat parlementaire lui-même qui a pu aboutir à une réforme électorale. Le système mixte de 1919, entre proportionnelle et principe majoritaire, exprime cette tendance des députés à l’ « auto-critique » qui dessine in fine un « auto-portrait ». Progressivement, les circulaires ministérielles adressées aux préfets confondent ces problèmes en un seul mouvement qui tente de codifier l’organisation des candidatures qui pourrait être au fondement du renouvellement souhaité. Ce travail préfectoral retire aux seuls entrepreneurs électoraux le monopole de l’anticipation des résultats et en ménage une co-production administrative. Dans la production préfectorale, de nouvelles cartes des circonscriptions uninominales ont eu tendance à perpétuer le traditionnel « scrutin d’arrondissement ». Ces tentatives de réforme électorale spatiale ont également introduit une nouvelle échelle dans le déroulement des campagnes électorales. Cet élargissement de la capacité électorale a été rendu possible par une nouvelle représentation : la circonscription administrative du département a eu tendance à devenir le critère principal de la mobilisation électorale que ce soit pour la loi électorale de 1919 ou celle de 1927. / Early twentieth century, after two decades of indifference to electoral reform, the electoral system has become a controversial question. This study explores the factors that should been taken into consideration when members of the French Chamber of Deputies and some other activists have tried to choose “proportional representation”. Beyond its political and legislative dimensions, the problem of re-election of representatives in the Third Republic was influenced by manipulation of electoral rules – in particular the introduction of proportional and list voting. In Paris and in Province, professors desert this part of doctrine in spite of some militant activities. Students had produced their thesis under constraint because the boards of examiners were always the same. We seek to explain how and why Parliament becomes leader in this electoral reform. Conservatives and Socialists advocated more strongly the proportional representation. The problem is often stated on the level in which every political party prefers the electoral system that favors it. This study will underline the biographical and social effect of membership stability instead of change in partisan control of the legislature. We seek to explain why a parliamentary debate may lead to a change in the established electoral system. The mixed system of 1919, between proportional representation and majority principle, expresses the deputies’ trends to self-criticism which is also self- representation. Increasingly, ministerial letters of instruction to Prefects tend to conflate these elements into a single effort to codify the pre-selection of candidates who could form the base of the desired political renewal. In this way, the monopoly of expertise relating to anticipating and predicting electoral outcomes once held political entrepreneurs was replaced by co-management of elections by them and the Prefects. First, new maps for single-seat districts have tended to perpetuate the traditionnal “scrutin d’arrondissement”. These attemps of spatial electoral reform have introduced a new scale in electoral campaign. This enlargement of electoral capability was made possible with a new representation : the administrative district of “département” has tended to become the main criterion in electoral mobilization whatever one of the two different electoral rules in 1919 and 1927.
252

The Use of Proportional Reasoning and Rational Number Concepts by Adults in the Workplace

January 2015 (has links)
abstract: Industry, academia, and government have spent tremendous amounts of money over several decades trying to improve the mathematical abilities of students. They have hoped that improvements in students' abilities will have an impact on adults' mathematical abilities in an increasingly technology-based workplace. This study was conducted to begin checking for these impacts. It examined how nine adults in their workplace solved problems that purportedly entailed proportional reasoning and supporting rational number concepts (cognates). The research focused on four questions: a) in what ways do workers encounter and utilize the cognates while on the job; b) do workers engage cognate problems they encounter at work differently from similar cognate problems found in a textbook; c) what mathematical difficulties involving the cognates do workers experience while on the job, and; d) what tools, techniques, and social supports do workers use to augment or supplant their own abilities when confronted with difficulties involving the cognates. Noteworthy findings included: a) individual workers encountered cognate problems at a rate of nearly four times per hour; b) all of the workers engaged the cognates primarily via discourse with others and not by written or electronic means; c) generally, workers had difficulty with units and solving problems involving intensive ratios; d) many workers regularly used a novel form of guess & check to produce a loose estimate as an answer; and e) workers relied on the social structure of the store to mitigate the impact and defuse the responsibility for any errors they made. Based on the totality of the evidence, three hypotheses were discussed: a) the binomial aspect of a conjecture that stated employees were hired either with sufficient mathematical skills or with deficient skills was rejected; b) heuristics, tables, and stand-ins were maximally effective only if workers individually developed them after a need was recognized; and c) distributed cognition was rejected as an explanatory framework by arguing that the studied workers and their environment formed a system that was itself a heuristic on a grand scale. / Dissertation/Thesis / Doctoral Dissertation Curriculum and Instruction 2015
253

Desenvolvimento de um sistema de emissao exoeletronica termicamente estimulada para a aplicacao em dosimetria

ROCHA, FELICIA DEL G. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:42:45Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:30Z (GMT). No. of bitstreams: 1 05225.pdf: 5071584 bytes, checksum: 1e93e518cbd529a7903fc24403a4234d (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
254

Determinação da taxa de desintegração de Tc-99m e In-111 em sistemas de coincidências / Desintegration rate of Tc-99m and In-111 radioactive solutions in coincidence systems

BRITO, ANDREIA B. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:34:11Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:46Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
255

A Influencia do padrao de calibracao e da composicao do residuo de amostras de agua na eficiencia de um contador proporcional para contagem alfa e beta total. Aplicacao no controle radiologico do IPEN-CNEN/SP

SANTOS, CECILIA M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:48:06Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:57Z (GMT). No. of bitstreams: 1 08716.pdf: 7231985 bytes, checksum: 03e0ae1f8cfad93fe1403076edaf1b9b (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
256

Avaliação do efeito das perdas de seguimento nas análises feitas pelo estimador produto - limite de Kaplan - Meier e pelo modelo de riscos proporcionais de Cox / The impact of the loss to follow-up when using the Kaplan Meier estimator and the Cox proportional hazard model

Marcia Moreira Holcman 20 April 2006 (has links)
Introdução: As técnicas mais comumente empregadas em análise de sobrevida que utilizam dados censurados são o estimador produto limite de Kaplan-Meier (KM) e o modelo de riscos proporcionais de Cox. Estas técnicas têm como suposição que a causa da perda de seguimento seja independente do tempo de sobrevida. Objetivo: O presente estudo visa a analisar o efeito das perdas de seguimento nestas duas técnicas. Material e Métodos: O estudo foi realizado utilizando-se o banco de dados dos pacientes cadastrados no Registro Hospitalar do Hospital do Câncer de São Paulo em 1994. Foram elaborados 28 bancos de dados simulando perdas informativas e não informativas. A perda informativa foi simulada transformando os óbitos em vivos, na proporção de 5 a 50%. A perda não informativa foi simulada através do sorteio de 5 a 50% do total do banco. O estimador de Kaplan-Meier (KM) foi utilizado para estimar a sobrevida acumulada no primeiro, terceiro e quinto ano de seguimento, e o modelo de riscos proporcionais de Cox para estimar as hazard ratio (HR). Todas as estimativas obtidas no KM e as HR's foram comparadas com os resultados do banco de dados original. Resultados: Houve maior proporção de perda nos pacientes com maior escolaridade, admitidos por convênio e particular e os menos graves (estádio I ou II). Quanto maior a proporção de perda informativa, maior a diferença alcançada nas estimativas realizadas pelo KM, verificando-se que a perda de seguimento superior a 15% acarretou diferenças superiores a 20% nas estimativas da probabilidade de sobrevida. As HR's foram menos afetadas, e proporções superiores a 20% de perda de seguimento acarretaram variações de cerca de 10% nas estimativas. Quando as perdas foram não informativas não houve diferenças significativas nas estimativas pelo KM e nas HR's em relação ao banco original. Conclusões: É importante avaliar se as perdas ocorridas em estudos de coorte são informativas ou não, pois se forem podem acarretar distorções principalmente nas estimativas feitas pelo método de KM. / Introduction: The Kaplan Meier product limit estimator (KM) and the Cox proportional hazard (HR) model are the most used tools in survival analysis. These two methods have the key assumption that censoring must be independent from the survival time. Objective: To analyze the consequences of loss to follow up in these two methods. Methods: The study has utilized the data of the Cancer Registry of the patients of Hospital do Cancer in São Paulo of 1994. The informative censure was simulated transforming the death by 5 to 50% into alive. Besides 5 to 50% was spared at random simulating the non-informative censoring. The survival probability and was calculated to the first, third and fifth year of follow –up. All the estimated probabilities and HR’s were compared with the results of the original data. Results: Patients with greater scholars, lower stages and admitted by health plans or private had more losses to follow up. The maximum proportion of accepted loss to follow –up is 10% to 15% when using the KM estimator, and the HR are less affected by the loss to follow-up and one can afford having 20% of it. When the losses were non informative there were no differences between the original probabilities. Conclusions: The possibility of over or under estimated probability must be analyzed in the presence of the losses to follow- up when using the KM and HR in survival analyses.
257

Desenvolvimento de um sistema de emissao exoeletronica termicamente estimulada para a aplicacao em dosimetria

ROCHA, FELICIA DEL G. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:42:45Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:30Z (GMT). No. of bitstreams: 1 05225.pdf: 5071584 bytes, checksum: 1e93e518cbd529a7903fc24403a4234d (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
258

Determinação da taxa de desintegração de Tc-99m e In-111 em sistemas de coincidências / Desintegration rate of Tc-99m and In-111 radioactive solutions in coincidence systems

BRITO, ANDREIA B. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:34:11Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:46Z (GMT). No. of bitstreams: 0 / Este trabalho apresenta os métodos de padronização de 111In e 99mTc, em sistemas de coincidências 4πβ-γ. O 111In foi produzido em cíclotron pela reação 111Cd(p, n)111In; decai com uma meia vida de 2,8 dias pelo processo de captura eletrônica populando os níveis excitados do 111Cd, emitindo raios gama de 171 keV e 245 keV. O 99mTc decai com uma meia vida de 6,007 h por transição isomérica do decaimento radioativo do 99Mo . A padronização do 111In foi feita no sistema 4πβ-γ constituído de um detector proporcional em geometria 4π acoplado a dois cristais cintiladores de NaI(Tl) com eletrônica convencional. A radiação gama selecionada para medida em coincidência foi de (171 + 245) keV. A escolha da janela gama foi baseada na análise da previsão da curva de extrapolação obtida na simulação de Monte Carlo. A padronização do 99mTc foi feita num sistema 4πβ-γ usando um contador proporcional de janela fina acoplado a um cristal de cintilação NaI (Tl). A eficiência beta foi variada por discriminação eletrônica, usando sistema de coincidências por software (SCS). A padronização do 99mTc foi feita pela seleção de dois intervalos gama, um no pico de absorção total de 140 keV e outro no pico de absorção total dos raios X de 20 keV. O resultado da atividade experimental de duas soluções de 111In concorda com o resultado obtido pela simulação de Monte Carlo. As atividades experimentais do 99mTc para os dois intervalos gama selecionados estão de acordo dentro da incerteza experimental, indicando que a metodologia adotada é adequada. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
259

A Influencia do padrao de calibracao e da composicao do residuo de amostras de agua na eficiencia de um contador proporcional para contagem alfa e beta total. Aplicacao no controle radiologico do IPEN-CNEN/SP

SANTOS, CECILIA M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:48:06Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:57Z (GMT). No. of bitstreams: 1 08716.pdf: 7231985 bytes, checksum: 03e0ae1f8cfad93fe1403076edaf1b9b (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
260

Detector de raios-X sensível à posição. / X-rays detector sensitive to the position.

Eduardo Luiz Augusto Macchione 04 December 1990 (has links)
Um contador a gás, com multifios, sensível à posição, para a detecção de raios X foi construído utilizando linhas de atraso integradas para leitura da posição. Seis linhas de atraso (50ns de atraso cada, frequência de corte de 40MHz) cobrem um comprimento sensível total de 150mm, possuindo uma razão do atraso total pelo tempo de subida dos sinais na linha adequadas para a detecção em posição raios X de 5,9keV do ANTIPOT. 55 Fe com alta resolução. Testes usando a forneceram uma não-linearidade linha de integral máxima menor que 0,1% e não-linearidade diferencial máxima de ±4,0%, com o detector utilizando a mistura 700torr. Testes similares foram feitos usando de Ar-CH IND 4 (90%-10%) a a linha de 8,04keV de um tubo de raios X de Cu. Uma resolução total de 330m, e as mesmas não-linearidades integral e diferencial foram obtidas. Com a finalidade de t.est.ar o comportamento do detector sob condições experimentais reais, duas diferentes amostras foram analisadas na região de espalhamento em baixo ângulo. As amostras analisadas foram o carvão vítreo e o dodecil sulfato de sódio (SLS). O feixe de raios X foi colimado por um conjunto de fendas, com 50,um cada uma delas e separadas de 98mm. A distância entre a amostra e o detector era de 404,5mm, fazendo com que a região sensível do detector cobrisse um ângulo de espalhamento de ±12 °. Foram obtidos um raio de giro de 22 Å para o carvão vítreo e um dos parâmetros da rede cristalina c de 39,1 Å para o SLS. Estes resultados estão de acordo com trabalhos anteriores obtidos com técnicas tradicionais de maior dispêndio de tempo que utilizam detectores de Nal(T1) e chapas fotográficas em uma câmara de Laue. / A multiware position sensitive gas counter for X-Ray detection was developed in our laboratory making use or commercial delay-lines for position sensing. Six delay-line chips (50ns delay each 40Mhz cut-off frequency) cover a total sensitive length of 190mm leading to a delay-risetime ratio that allows for a high-resolution position detection. Tests using the 5,9keV X-Ray line from a 55Fe source an integral linearity better than 0,1% and a maximum differential linearity or ±4,0% were obtained operating the detector with an Ar-CH 4 (90%-10%) gas mixture at 700torr. Similar tests were performed using the 8,04keV line from a Cu X-Ray tube. A total resolution or 330m, and the same integral and differential linearities were obtained. In order to check the detector performance under usual experimental conditions two different samples were analyzed in the low scattering-angle region. The samples analyzed were vitreous carbon and sodium dodecyl sulfate (SLS). The X-Rays were collimated by a set or slits each 50m wide separated by 98mm. The distance between the sample and the detector was 404,5mm, so that the detector covered a scattering angle of ±12°. A radius of gyration of 22Å for vitreous carbon and a crystallographic parameter of 39,1Å for SLS were obtained. These values are in good agreement with those obtained with the more time-consuming traditional techniques making use of a rotating NaI(T1) detector and photographic plates with a Laue camera.

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