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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Méthodes de simulations moléculaires accélérées : application et développement

St-Pierre, Jean-François January 2006 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
2

O mercado internacional de petróleo: a influência da OPEP e o poder de mercado / The international oil market: the influence of OPEC and the market power

Maxir, Henrique dos Santos 20 January 2016 (has links)
A criação da Organização dos Países Exportadores de Petróleo (OPEP) foi um marco para o mercado internacional de petróleo. Para a opinião pública a OPEP é um cartel devido aos choques do petróleo ocorridos na década de 1970, porém na literatura econômica não existe consenso sobre a OPEP ser ou não um cartel. Sob a ótica da teoria dos cartéis, esta pesquisa tem como objetivo evidenciar o papel da OPEP e verificar se a mesma exerce poder de mercado, demonstrando aspectos históricos que desencadearam na sua criação e suas principais ações ao longo do tempo. No primeiro artigo, através de uma análise fundamentada na distinção entre os países da OPEP e os Não-OPEP, foram utilizados indicadores sobre o mercado internacional de petróleo, destacando os principais detentores das reservas provadas, os produtores, os consumidores, a evolução dos preços, o comércio internacional, as emissões de CO2 geradas a partir da combustão do combustível fóssil e a ascensão dos biocombustíveis. Os resultados mostraram que a dotação natural é fator determinante na produção e no comércio internacional de petróleo, e que os países membros da OPEP são altamente dependentes das divisas geradas das exportações de petróleo para sustentação de importações de outros bens. Verificou-se que os países da OPEP vêm aumentando seu consumo interno de petróleo, gerando maiores emissões de CO2, o que reforça ainda mais a dependência do petróleo como principal fonte na matriz energética destes países. Neste cenário, os biocombustíveis vêm ganhando espaço principalmente nos países Não-OPEP. A OPEP é uma Organização formada por países, assim seus objetivos vão além da maximização de lucros. Entretanto, as diferenças macroeconômicas entre os membros relacionadas aos diferentes regimes políticos, com objetivos destoantes de curto e de longo prazo, são fatores limitadores na ação coordenada entre os membros. No segundo artigo desta pesquisa, através do modelo estático da Nova Organização Industrial Empírica (New Empirical Industrial Organization - NEIO) foi identificado o grau de poder de mercado no comércio internacional de petróleo no período de janeiro de 2003 até março de 2015. Os resultados mostraram que o mercado internacional de petróleo está distante da estrutura de monopólio ou cartel perfeito, e não são estatisticamente descartadas as hipóteses de competição via Cournot e de competição perfeita. / The establishment of the Organization of Petroleum Exporting Countries (OPEC) was a historic milestone for the international oil market. For the public opinion the OPEC is considered as a cartel due to the oil shocks in the 1970s, but in the economic literature there is no consensus if OPEC really acts as cartel. However, we use the theory of cartels to highlight the role of OPEC and identify if there is market power exercise in the international oil market. We present historical aspects that led in OPEC creation and its main actions over time. In the first chapter, we use an analysis based on the distinction between the OPEC and non-OPEC countries. We identify the main countries which holds proven reserves, the major producers, consumers, the trend of price, the international trade, the CO2 emissions generated by the fossil fuel combustion and the rise of biofuels production. The results indicate that the natural endowment is a key factor to the production and international trade of oil, and OPEC members are highly dependent on oil exports revenue to sustain other goods imports. OPEC countries increased domestic oil consumption, generating more CO2 emissions, which demonstrates the increase of oil dependency in the energy matrix of these countries. According to the current scenario, the biofuels production has increased mainly in non-OPEC countries. OPEC is an organization formed by countries and their goals are not only to maximize profits, and so, OPEC is a political union that has stability over the years. However, macroeconomic differences among members related to different political regimes with different shortterm and long-term goals that are limiting factors for coordinated action. Therefore, according to the theory of the cartel formation and sustainability, OPEC has difficulties to fix prices or quantity on the international oil market, the Organization does not behave like a cartel most of the time. In the second chapter the static model of the New Empirical Industrial Organization (NEIO) is used to identify the degree of market power in the international oil market during the period from January 2003 to March 2015. The results indicated that the international oil market is not characterized by a cartel, but are not statistically rejected the hypothesis of Cournot competition nor perfect competition.
3

O mercado internacional de petróleo: a influência da OPEP e o poder de mercado / The international oil market: the influence of OPEC and the market power

Henrique dos Santos Maxir 20 January 2016 (has links)
A criação da Organização dos Países Exportadores de Petróleo (OPEP) foi um marco para o mercado internacional de petróleo. Para a opinião pública a OPEP é um cartel devido aos choques do petróleo ocorridos na década de 1970, porém na literatura econômica não existe consenso sobre a OPEP ser ou não um cartel. Sob a ótica da teoria dos cartéis, esta pesquisa tem como objetivo evidenciar o papel da OPEP e verificar se a mesma exerce poder de mercado, demonstrando aspectos históricos que desencadearam na sua criação e suas principais ações ao longo do tempo. No primeiro artigo, através de uma análise fundamentada na distinção entre os países da OPEP e os Não-OPEP, foram utilizados indicadores sobre o mercado internacional de petróleo, destacando os principais detentores das reservas provadas, os produtores, os consumidores, a evolução dos preços, o comércio internacional, as emissões de CO2 geradas a partir da combustão do combustível fóssil e a ascensão dos biocombustíveis. Os resultados mostraram que a dotação natural é fator determinante na produção e no comércio internacional de petróleo, e que os países membros da OPEP são altamente dependentes das divisas geradas das exportações de petróleo para sustentação de importações de outros bens. Verificou-se que os países da OPEP vêm aumentando seu consumo interno de petróleo, gerando maiores emissões de CO2, o que reforça ainda mais a dependência do petróleo como principal fonte na matriz energética destes países. Neste cenário, os biocombustíveis vêm ganhando espaço principalmente nos países Não-OPEP. A OPEP é uma Organização formada por países, assim seus objetivos vão além da maximização de lucros. Entretanto, as diferenças macroeconômicas entre os membros relacionadas aos diferentes regimes políticos, com objetivos destoantes de curto e de longo prazo, são fatores limitadores na ação coordenada entre os membros. No segundo artigo desta pesquisa, através do modelo estático da Nova Organização Industrial Empírica (New Empirical Industrial Organization - NEIO) foi identificado o grau de poder de mercado no comércio internacional de petróleo no período de janeiro de 2003 até março de 2015. Os resultados mostraram que o mercado internacional de petróleo está distante da estrutura de monopólio ou cartel perfeito, e não são estatisticamente descartadas as hipóteses de competição via Cournot e de competição perfeita. / The establishment of the Organization of Petroleum Exporting Countries (OPEC) was a historic milestone for the international oil market. For the public opinion the OPEC is considered as a cartel due to the oil shocks in the 1970s, but in the economic literature there is no consensus if OPEC really acts as cartel. However, we use the theory of cartels to highlight the role of OPEC and identify if there is market power exercise in the international oil market. We present historical aspects that led in OPEC creation and its main actions over time. In the first chapter, we use an analysis based on the distinction between the OPEC and non-OPEC countries. We identify the main countries which holds proven reserves, the major producers, consumers, the trend of price, the international trade, the CO2 emissions generated by the fossil fuel combustion and the rise of biofuels production. The results indicate that the natural endowment is a key factor to the production and international trade of oil, and OPEC members are highly dependent on oil exports revenue to sustain other goods imports. OPEC countries increased domestic oil consumption, generating more CO2 emissions, which demonstrates the increase of oil dependency in the energy matrix of these countries. According to the current scenario, the biofuels production has increased mainly in non-OPEC countries. OPEC is an organization formed by countries and their goals are not only to maximize profits, and so, OPEC is a political union that has stability over the years. However, macroeconomic differences among members related to different political regimes with different shortterm and long-term goals that are limiting factors for coordinated action. Therefore, according to the theory of the cartel formation and sustainability, OPEC has difficulties to fix prices or quantity on the international oil market, the Organization does not behave like a cartel most of the time. In the second chapter the static model of the New Empirical Industrial Organization (NEIO) is used to identify the degree of market power in the international oil market during the period from January 2003 to March 2015. The results indicated that the international oil market is not characterized by a cartel, but are not statistically rejected the hypothesis of Cournot competition nor perfect competition.
4

Lattice model for amyloid peptides : OPEP force field parametrization and applications to the nucleus size of Alzheimer's peptides / Modèle réseau de peptides amyloïdes : paramétrisation du champ de forces OPEP et application aux noyaux de nucléation de peptides d'Alzheimer

Tran, Thanh Thuy 20 September 2016 (has links)
La maladie d’Alzheimer touche plus de 40 millions de personnes dans le monde et résulte de l’agrégation du peptide beta-amyloïde de 40/42 résidus. En dépit de nombreuses études expérimentales et théoriques, le mécanisme de formation des fibres et des plaques n’est pas élucidé, et les structures des espèces les plus toxiques restent à déterminer. Dans cette thèse, je me suis intéressée à deux aspects. (1) La détermination du noyau de nucléation (N*) de deux fragments (Aβ)16-22 et (Aβ)37-42. Mon approche consiste à déterminer les paramètres OPEP du dimère (Aβ)16-22 en comparant des simulations Monte Carlo sur réseau et des dynamiques moléculaires atomiques par échange de répliques. Les paramètres fonctionnant aussi sur le trimère (Aβ)16-22 et les dimères et trimères (Aβ)37-42, j’ai étudié la surface d’énergie libre des décamères et mes simulations montrent que N* est de 10 chaines pour (Aβ)16-22 et est supérieure à 20 chaines pour (Aβ)37-42. (2) J’ai ensuite étudié les structures du dimère (Aβ)1-40 par simulations de dynamique moléculaire atomistique par échanges de répliques. Cette étude, qui fournit les conformations d’équilibre du dimère Aβ1-40 en solution aqueuse, ouvre des perspectives pour une compréhension de l’impact des mutations pathogènes et protectrices au niveau moléculaire. / The neurodegenerative Alzheimer's disease (AD) is affecting more than 40 million people worldwide and is linked to the aggregation of the amyloid-β proteins of 40/42 amino acids. Despite many experimental and theoretical studies, the mechanism by which amyloid fibrils form and the 3D structures of the early toxic species in aqueous solution remain to be determined. In this thesis, I studied the structures of the eraly formed oligomers of the amyloid-β peptide and the critical nucleus size of two amyloid-β peptide fragments using either coarse-grained or all-atom simulations. First, at the coarse-grained level, I developed a lattice model for amyloid protein, which allows us to study the nucleus sizes of two experimentally well-characterized peptide fragments (Aβ)16-22 and (Aβ)37-42 of the Alzheimer's peptide (Aβ)1-42. After presenting a comprehensive OPEP force-field parameterization using an on-lattice protein model with Monte Carlo simulations and atomistic simulations, I determined the nucleus sizes of the two fragments. My results show that the nucleation number is 10 chains for (Aβ)16-22 and larger than 20 chains for (Aβ)37-42. This knowledge is important to help design more effective drugs against AD. Second, I investigated the structures of the dimer (Aβ)1-40 using extensive atomistic REMD simulations. This study provides insights into the equilibrium structure of the (Aβ)1-40 dimer in aqueous solution, opening a new avenue for a comprehensive understanding of the impact of pathogenic and protective mutations in early-stage Alzheimer’s disease on a molecular level.
5

Développement et optimisation des potentiels OPEP et simulations numériques de la protéine Huntingtine

Binette, Vincent 04 1900 (has links)
No description available.
6

Conceptualization And Measurement Of Organizational Patent Externalization Potential In R&D : Insights For Organization Design And Practice

Chakraborty, Nilanjana Bhaduri 08 1900 (has links)
Organizations have realized that they need to develop and strategically utilize their patent portfolios in order to maintain sustainable competitive advantage. This requires a change in the organization design and practice. Prior studies have addressed this in context of increasing patent productivity, i.e., process of filing patents (Shapiro, 1990; Berkowitz, 1993; Ransley and Gaffney, 1997; Chattopadhyay, 2003). But there have been lacunae in addressing issues in organization design and practice for ensuring patent utilization, which forms the focus of this thesis. Patent externalization is defined the process of translating embedded intellectual value of a patent into “externalized” knowledge and financial benefits. The objectives of the thesis have been to conceptualize a model and measure high and low variances in organizational patent externalization potential, to understand significant organization-level practices that differentiates between organizations having high and low patent externalization potential, to understand differences in organizational perceptions about knowledge and financial orientation of the patent externalization practices in organizations having high and low patent externalization potential and to suggest changes in practices that would enhance organizational patent externalization potential. Towards this purpose, prior literature related to patent productivity and organization change were studied and a conceptual model was developed. The conceptual model outlines that the organizational design components – organizational practices supporting patenting outcomes, competitive intelligence gathering practices and patent commercialization practices alongwith organization and individual moderating variables determine the organizational patent externalization potential. This model was initially verified through exploratory case studies across seven R&D intensive organizations. Variables identified from literature review and initial case studies, were operationally defined and measurement models for the thesis were developed. A questionnaire comprising of 160 items (validated items measuring the aforementioned variables) was designed for conducting the survey research. The measurement scale used was a 5-point Likert-type interval scale. . A Cronbach alpha of 0.82 was obtained for the questionnaire. The sample comprised of professionals from four sectors – pharmaceutical, IT, manufacturing and academia. The sample size was 56 organizations representing 208 professionals. To accommodate the influence of the moderating variables, data was collected from professionals having commercialized patents, whose patents were yet to be commercialized and those having no patent commercialization experience. The statistical techniques used for data analysis were: principal component analysis, hierarchical cluster analysis, discriminant analysis, F-test, t-test and chi-square tests. This thesis provides insights into various practices and perceptions that are essential design components in enhancing organizational patent externalization potential. These findings have implications for OD managers. The thesis contributes both to the theory of patent management and change management literature. Additionally, the questionnaire designed for this study has potential for being used as a diagnostic tool to assess potential for organizational change. Limitations and future areas of study are also addressed.
7

Oil price shocks and policy implications the emergence of U.S. tight oil production: a case study

Voth, Jeffrey Michael 26 October 2015 (has links)
Submitted by Daniele Santos (danielesantos.htl@gmail.com) on 2015-12-22T14:02:29Z No. of bitstreams: 1 Jeffrey.pdf: 11824596 bytes, checksum: e53f7ce72384381247ec95015dbe102d (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2015-12-29T12:29:01Z (GMT) No. of bitstreams: 1 Jeffrey.pdf: 11824596 bytes, checksum: e53f7ce72384381247ec95015dbe102d (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2016-01-06T17:15:02Z (GMT) No. of bitstreams: 1 Jeffrey.pdf: 11824596 bytes, checksum: e53f7ce72384381247ec95015dbe102d (MD5) / Made available in DSpace on 2016-01-06T17:15:15Z (GMT). No. of bitstreams: 1 Jeffrey.pdf: 11824596 bytes, checksum: e53f7ce72384381247ec95015dbe102d (MD5) Previous issue date: 2015-10-26 / How have shocks to supply and demand affected global oil prices; and what are key policy implications following the resurgence of oil production in the United States? Highlights: − The recent collapse in global oil prices was dominated by oversupply. − The future of tight oil in the United States is vulnerable to obstacles beyond oil prices. − Opinions on tight oil from the Top 25 think tank organizations are considered. Global oil prices have fallen more than fifty percent since mid-2014. While price corrections in the global oil markets resulted from multiple factors over the past twelve months, surging tight oil production from the United States was a key driver. Tight oil is considered an unconventional or transitional oil source due to its location in oil-bearing shale instead of conventional oil reservoirs. These qualities make tight oil production fundamentally different from regular crude, posing unique challenges. This case study examines these challenges and explores how shocks to supply and demand affect global oil prices while identifying important policy considerations. Analysis of existing evidence is supported by expert opinions from more than one hundred scholars from top-tier think tank organizations. Finally, implications for United States tight oil production as well as global ramifications of a new low price environment are explored.
8

Essays on the Liquidity Trap, Oil Shocks, and the Great Moderation

Nakov, Anton 19 November 2007 (has links)
The thesis studies three distinct issues in monetary economics using a common dynamic general equilibrium approach under the assumptions of rational expectations and nominal price rigidity. The first chapter deals with the so-called "liquidity trap" - an issue which was raised originally by Keynes in the aftermath of the Great Depression. Since the nominal interest rate cannot fall below zero, this limits the scope for expansionary monetary policy when the interest rate is near its lower bound. The chapter studies the conduct of monetary policy in such an environment in isolation from other possible stabilization tools (such as fiscal or exchange rate policy). In particular, a standard New Keynesian model economy with Calvo staggered price setting is simulated under various alternative monetary policy regimes, including optimal policy. The challenge lies in solving the (otherwise linear) stochastic sticky price model with an explicit occasionally binding non-negativity constraint on the nominal interest rate. This is achieved by parametrizing expectations and applying a global solution method known as "collocation". The results indicate that the dynamics and sometimes the unconditional means of the nominal rate, inflation and the output gap are strongly affected by uncertainty in the presence of the zero lower bound. Commitment to the optimal rule reduces unconditional welfare losses to around one-tenth of those achievable under discretionary policy, while constant price level targeting delivers losses which are only 60% larger than under the optimal rule. On the other hand, conditional on a strong deflationary shock, simple instrument rules perform substantially worse than the optimal policy even if the unconditional welfare loss from following such rules is not much affected by the zero lower bound per se. The second thesis chapter (co-authored with Andrea Pescatori) studies the implications of imperfect competition in the oil market, and in particular the existence of a welfare-relevant trade-off between inflation and output gap volatility. In the standard New Keynesian model exogenous oil shocks do not generate any such tradeoff: under a strict inflation targeting policy, the output decline is exactly equal to the efficient output contraction in response to the shock. I propose an extension of the standard model in which the existence of a dominant oil supplier (such as OPEC) leads to inefficient fluctuations in the oil price markup, reflecting a dynamic distortion of the economy's production process. As a result, in the face of oil sector shocks, stabilizing inflation does not automatically stabilize the distance of output from first-best, and monetary policymakers face a tradeoff between the two goals. The model is also a step away from discussing the effects of exogenous oil price changes and towards analyzing the implications of the underlying shocks that cause the oil price to change in the first place. This is an advantage over the existing literature, which treats the macroeconomic effects and policy implications of oil price movements as if they were independent of the underlying source of disturbance. In contrast, the analysis in this chapter shows that conditional on the source of the shock, a central bank confronted with the same oil price change may find it desirable to either raise or lower the interest rate in order to improve welfare. The third thesis chapter (co-authored with Andrea Pescatori) studies the extent to which the rise in US macroeconomic stability since the mid-1980s can be accounted for by changes in oil shocks and the oil share in GDP. This is done by estimating with Bayesian methods the model developed in the second chapter over two samples - before and after 1984 - and conducting counterfactual simulations. In doing so we nest two other popular explanations for the so-called "Great Moderation": (1) smaller (non-oil) shocks; and (2) better monetary policy. We find that the reduced oil share can account for around one third of the inflation moderation, and about 13% of the GDP growth moderation. At the same time smaller oil shocks can explain approximately 7% of GDP growth moderation and 11% of the inflation moderation. Thus, the oil share and oil shocks have played a non-trivial role in the moderation, especially of inflation, even if the bulk of the volatility reduction of output growth and inflation is attributed to smaller non-oil shocks and better monetary policy, respectively. / La tesis estudia tres problemas distintos de macroeconomía monetaria utilizando como marco común el equilibrio general dinámico bajo expectativas racionales y con rigidez nominal de los precios. El primer capítulo trata el problema de la "trampa de liquidez" - un tema planteado primero por Keynes después de la Gran Depresión de 1929. El hecho de que el tipo de interés nominal no pueda ser negativo limita la posibilidad de llevar una política monetaria expansiva cuando el tipo de interés se acerca a cero. El capítulo estudia la conducta de la política monetaria en este entorno en aislamiento de otros posibles instrumentos de estabilización (como la política fiscal o la política de tipo de cambio). En concreto, se simula un modelo estándar Neo-Keynesiano con rigidez de precios a la Calvo bajo diferentes regimenes de política monetaria, incluida la política monetaria óptima. El reto consiste en resolver el modelo estocástico bajo la restricción explícita ocasionalmente vinculante de no negatividad de los tipos de interés. La solución supone parametrizar las expectativas y utilizar el método de solución global conocido como "colocación". Los resultados indican que la dinámica y en ocasiones los valores medios del tipo de interés, la inflación y el output gap están muy influidos por la presencia de la restricción de no negatividad. El compromiso con la regla monetaria óptima reduce las pérdidas de bienestar esperadas hasta una décima parte de las pérdidas obtenidas bajo la mejor política discrecional, mientras una política de meta constante del nivel de precios resulta en pérdidas que son sólo 60% mayores de las obtenidas bajo la regla óptima. Por otro lado, condicionado a a un choque fuerte deflacionario, las reglas instrumentarias simples funcionan mucho peor que la política óptima, aun si las pérdidas no condicionales de bienestar asociadas a dichas reglas no están muy afectadas por la presencia de la restricción de no negatividad en si. El segundo capítulo de la tesis estudia las implicaciones de la competencia imperfecta en el mercado del petróleo, y en concreto la existencia de un conflicto relevante entre la volatilidad de la inflación y la del output gap de un país importador de petróleo. En el modelo estándar Neo Keynesiano, los choques petroleros exógenos no generan ningún conflicto de objetivos: bajo una política de metas de inflación estricta, la caída del output es exactamente igual a la contracción eficiente del output en respuesta al choque. Este capitulo propone una extensión del modelo básico en la cual la presencia de un proveedor de petróleo dominante (OPEP) lleva a fluctuaciones ineficientes en el margen del precio del petróleo que reflejan una distorsión dinámica en el proceso de producción de la economía. Como consecuencia, ante choques provinientes del sector de petróleo, una política de estabilidad de los precios no conlleva automáticamente a una estabilización de la distancia del output de su nivel eficiente y existe un conflicto entre los dos objetivos. El modelo se aleja de la discución los efectos de cambios exógenos en el precio del petróleo y se acerca al análisis de las implicaciones de los factores fundamentales que provocan los cambios en el precio del petróleo en primer lugar. Esto último representa una ventaja clara frente a la literatura existente, la cual trata tanto los efectos macroeconómicos como las implicaciones para la política monetaria de cambios en el precio del petróleo como si éstos fueran independientes de los factores fundamentales provocando dicho cambio. A diferencia de esta literatura, el análisis del capitulo II demuestra cómo frente al mismo cambio en el precio del petróleo, un banco central puede encontrar deseable bien subir o bajar el tipo de interés en función del origen del choque. El tercer capitulo estudia el grado en que el ascenso de la estabilidad macroeconómica en EE.UU. a partir de mediados de los 80 se puede atribuir a cambios en la naturaleza de los choques petroleros y/o el peso del petróleo en el PIB. Con este propósito se estima el modelo desarrollado en el capitulo II con métodos Bayesianos utilizando datos macroeconómicos de dos periodos - antes y después de 1984 - y se conducen simulaciones contrafactuales. Las simulaciones permiten dos explicaciones alternativas de la "Gran Moderación": (1) menores choques no petroleros; y (2) mejor política monetaria. Los resultados apuntan a que el petróleo ha jugado un papel no-trivial en la moderación. En particular, el menor peso del petroleo en el PIB a partir de 1984 ha contribuido a una tercera parte de la moderación de la inflación y un 13% de la moderación del output. Al mismo tiempo, un 7% de la moderación del PIB y 11% de la moderación de la inflación se pueden atribuir a menores choques petroleros.

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