Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-09-15T17:59:28Z No. of bitstreams: 1 AugustoSilva.pdf: 4699819 bytes, checksum: cf18a43cf817a3264880d015853561f6 (MD5) / Made available in DSpace on 2017-09-15T17:59:29Z (GMT). No. of bitstreams: 1 AugustoSilva.pdf: 4699819 bytes, checksum: cf18a43cf817a3264880d015853561f6 (MD5) Previous issue date: 2017-08-16 / In this work the theoretical study of the bimetallic clusters of Au-Ag and Au-Cu was carried out, in which such clusters were determined by the addition of Ag and Cu atoms in pure structures of Au clusters, through the GA-DFT joint methodology. The AuCu and Au-Ag structures were described in a classical way using the Gupta potential via the genetic algorithm. The lower energy structures were optimized via DFT using the PBE functional through the SIESTA 3.2 program package. The most stable clusters were those with 13 atoms for Au-Ag bimetallic clusters, Au-Cu bimetallic clusters stabilized with 13, 15 and 20 atoms. Both clusters have a degree of aromaticity, more pronounced in the AuAg atoms, than in the Au-Cu atoms. The Au-Ag clusters adsorb the oxygen more favorably in end-on or bridge, whereas the bimetallic clusters of Au-Cu adsorb the molecular oxygen generally according to the bridge or double bridge model. The adsorption of oxygen in bimetallic clusters is intrinsically related to the ability of oxygen to perform π backdonation for the metallic atoms in the cluster. / Neste trabalho fora realizado o estudo teórico dos clusters bimetálicos de Au-Ag e Au-Cu, em que tais clusters foram determinados através da adição de átomos de Ag e Cu em estruturas puras de clusters de Au, através da metodologia conjunta GA-DFT. As estruturas de Au-Cu e Au-Ag, foram descritas de forma clássica usando o potencial Gupta via algoritmo genético. As estruturas de mais baixa energia foram otimizadas via DFT usando o funcional PBE através do pacote de programas SIESTA 3.2. Os clusters de maior estabilidade foram os com 13 átomos para clusters bimetálicos de Au-Ag, os clusters bimetálicos de Au-Cu estabilizaram com 13, 15 e 20 átomos. Ambos os clusters possuem um certo grau de aromaticidade, mais pronunciada nos átomos de Au-Ag, que nos átomos de Au-Cu. Os clusters de Au-Ag adsorvem o oxigênio de forma mais favorável em end-on ou ponte, enquanto que os clusters bimetálicos de Au-Cu adsorvem o oxigênio molecular em geral segundo o modelo ponte ou dupla ponte. A adsorção do oxigênio nos clusters bimetálicos está intrinsecamente relacionada à habilidade do oxigênio em realizar retrodoação π para os átomos metálicos.

Este trabalho tem como objetivo principal desenvolver um sistema de avaliação de desempenho de clusters, capaz de analisar as vantagens potenciais que um cluster pode oferecer e concluir a respeito do aproveitamento dessas vantagens e dos aspectos que podem ser aprimorados. Para isso, o trabalho se propõe a: (i) identificar os constructos e variáveis que devem ser utilizados para representar as vantagens potenciais que um cluster industrial pode oferecer; (ii) desenvolver um sistema de avaliação do aproveitamento das vantagens potenciais de um cluster, baseado nos constructos e variáveis identificados; (iii) testar o sistema, avaliando o nível de desenvolvimento, no que tange ao aproveitamento de vantagens potenciais em que se encontra o cluster moveleiro do Oeste de Santa Catarina; e (iv) estabelecer um plano para aprimoramento das operações e consolidação do referido cluster. Esta tese está baseada numa abordagem quantitativa e qualitativa, utilizando questionário aplicado em 112 empresas, grupo focado e entrevistas. Uma das principais contribuições desta tese é a proposição de um modelo capaz de avaliar o aproveitamento das vantagens potenciais de um cluster, auxiliando na tomada de decisão dos envolvidos (poder público, instituições de classe, empresas) e melhoria da competitividade das empresas do cluster em relação às empresas externas. Outra contribuição deste trabalho é a proposição de ações que possam aumentar o aproveitamento das vantagens oferecidas às empresas pertencentes ao cluster moveleiro do oeste de Santa Catarina e à sua competitividade. / The main objective of this work is to develop a performance evaluation system of clusters, able of analyzing the potential advantages that a cluster can offer to its member companies and conclude about the use of these advantages and about the aspects which could be improved. Considering this general objective, this work intends: (i) identify the constructs and variables that should be utilized for represent the potential advantages that an industrial cluster can offer; (ii) develop an evaluation system for access the use of the potential advantages of a cluster, based on the constructs and identified variables; (iii) test the system, evaluating the development level of the west of Santa Catarina furniture cluster, regarding the use of the potential advantages, (iv) establish a plan for the improvement of operations and consolidation of the mentioned cluster. This dissertation is based on a qualitative and quantitative approach, comprising a survey involving 112 companies, focus group and interviews. One of the main contributions of this dissertation is the proposal of a model capable of evaluate the use of the potential advantages of a cluster, assisting on the decision making of the stakeholders (government, class association and companies) and competitiveness improvement of the cluster member companies compared to outside companies. Other contribution of this work is the proposal of a plan of actions that could increase the use of the advantages offered to the member companies of the west of Santa Catarina furniture cluster and their respective competitiveness.

Li, Qiuhui. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 46-47). / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- An overview of the BitTorrent protocol --- p.3 / Chapter 2 --- Problem Formulation --- p.7 / Chapter 2.1 --- Type-based Peer Selection Algorithm --- p.7 / Chapter 2.2 --- Clustering Index --- p.9 / Chapter 3 --- Model Formulation --- p.11 / Chapter 3.1 --- Markovian Model --- p.12 / Chapter 3.2 --- Transition Matrix --- p.14 / Chapter 3.2.1 --- Search Process --- p.16 / Chapter 3.2.2 --- Match Process --- p.18 / Chapter 3.2.3 --- Cut Process --- p.19 / Chapter 3.3 --- Open System Model --- p.21 / Chapter 4 --- Numerical Results and Observations --- p.24 / Chapter 4.1 --- Clustering Index --- p.24 / Chapter 4.2 --- Upload Utilization --- p.26 / Chapter 4.3 --- Download Rate --- p.28 / Chapter 4.4 --- Open System --- p.30 / Chapter 5 --- Performance Evaluation --- p.32 / Chapter 5.1 --- Model Verification --- p.34 / Chapter 5.2 --- Control the Clustering Index --- p.36 / Chapter 6 --- Related Works --- p.40 / Chapter 7 --- Conclusions --- p.44 / Bibliography --- p.46

Fung, Chun Yip. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 53-54). / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- The Exchange Algorithm Framework --- p.4 / Chapter 2.1 --- Ordinary Least Squares Linear Regression --- p.5 / Chapter 2.2 --- The Exchange Algorithm --- p.6 / Chapter 3 --- Methodology --- p.12 / Chapter 3.1 --- Least Median Squares Linear Regression --- p.12 / Chapter 3.2 --- Least Median Squares Algorithm for Clusterwise Linear Re- gression --- p.16 / Chapter 3.3 --- Measures of Performance --- p.20 / Chapter 3.4 --- An Illustrative Example --- p.24 / Chapter 4 --- Monte Carlo Simulation Study --- p.34 / Chapter 4.1 --- Simulation Plan --- p.34 / Chapter 4.2 --- Simulation Results --- p.41 / Chapter 4.2.1 --- Effects of the Six factors --- p.41 / Chapter 4.2.2 --- Comparisons between LMSA and the Exchange Algorithm --- p.47 / Chapter 4.2.3 --- Evaluation of the Improvement of Regression Parame- ters by Performing Stage 3 in LMSA --- p.50 / Chapter 5 --- Concluding Remarks --- p.51 / Bibliography --- p.52

Zhou, Tu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 61-70). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.0 / Chapter 1.1 --- Motivation and Objective --- p.0 / Chapter 1.2 --- Major Contribution --- p.2 / Chapter 1.3 --- Thesis Organization --- p.4 / Chapter 2 --- Measurement of Relationship between financial time series --- p.5 / Chapter ´ب2.1 --- Linear Correlation --- p.5 / Chapter 2.1.1 --- Pearson Correlation Coefficient --- p.6 / Chapter 2.1.2 --- Rank Correlation --- p.6 / Chapter 2.2 --- Mutual Information --- p.7 / Chapter 2.2.1 --- Approaches of Mutual Information Estimation --- p.10 / Chapter 2.3 --- Copula --- p.12 / Chapter 2.4 --- Analysis from Experimental Data --- p.14 / Chapter 2.4.1 --- Experiment 1: Nonlinearity --- p.14 / Chapter 2.4.2 --- Experiment 2: Sensitivity of Outliers --- p.16 / Chapter 2.4.3 --- Experiment 3: Transformation Invariance --- p.20 / Chapter 2.5 --- Chapter Summary --- p.23 / Chapter 3 --- Clustered Dynamic Conditional Correlation Model --- p.26 / Chapter 3.1 --- Background Review --- p.26 / Chapter 3.1.1 --- GARCH Model --- p.26 / Chapter 3.1.2 --- Multivariate GARCH model --- p.29 / Chapter 3.2 --- DCC Multivariate GARCH Models --- p.31 / Chapter 3.2.1 --- DCC GARCH Model --- p.31 / Chapter 3.2.2 --- Generalized DCC GARCH Model --- p.32 / Chapter 3.2.3 --- Block-DCC GARCH Model --- p.32 / Chapter 3.3 --- Clustered DCC GARCH Model --- p.34 / Chapter 3.3.1 --- Minimum Distance Estimation (MDE) --- p.36 / Chapter 3.3.2 --- Clustered DCC (CDCC) based on MDE --- p.37 / Chapter 3.4 --- Clustering Method Selection --- p.40 / Chapter 3.5 --- Model Estimation and Testing Method --- p.42 / Chapter 3.5.1 --- Maximum Likelihood Estimation --- p.42 / Chapter 3.5.2 --- Box-Pierce Statistic Test --- p.44 / Chapter 3.6 --- Chapter Summary --- p.44 / Chapter 4 --- Experimental Result and Applications on CDCC --- p.46 / Chapter 4.1 --- Model Comparison and Analysis --- p.46 / Chapter 4.2 --- Portfolio Selection Application --- p.50 / Chapter 4.3 --- Value at Risk Application --- p.52 / Chapter 4.4 --- Chapter Summary --- p.55 / Chapter 5 --- Conclusion --- p.57 / Bibliography --- p.61

Economia / Master in Economics / Num mundo onde o paradigma da globalização se tornou uma realidade inquestionável, a dimensão `local tem ganho particular interesse como objecto de análise. Isto decorre do facto de os principais factores de competitividade global se encontrarem profundamente enraizados a um nível local. Neste contexto, os clusters, como entidades geográficas e sócio-relacionais, com um percurso evolutivo específico, uma identidade institucional e dinâmicas locais de conhecimento, tornaram-se elementos cruciais no desenvolvimento das regiões, assumindo um papel significativo nas políticas públicas. Apesar da sua importância crescente, o conceito de cluster tem sido alvo de uma aplicação discricionária, em termos do seu sentido e definição. Tendo em conta a evolução histórica deste conceito, tornou-se, então, necessário encontrar uma forma de organizar a literatura existente, numa tentativa de harmonizar esta multiplicidade de interpretações e significados. Esta dissertação tem por objectivo sistematizar o actual corpo de abordagens teóricas e estudos empíricos sobre clusters através de uma revisão aprofundada da literatura, complementada com um estudo bibliométrico, realizado com base em artigos publicados em jornais indexados nas bases de dados bibliográficas Econlit e EBSCO, no período de 1962 a 2007. Os principais resultados deste trabalho de investigação indicam que, para além da sua importância académica, o papel dos clusters tem também sido amplamente reconhecido no domínio político. Por outro lado, o interesse crescente na dimensão `local tem sido acompanhado por um emergente corpo de literatura sobre `globalização, redes globais e clusters . Além disso, por detrás do recente boom na literatura sobre clusters, está a importância de temas como as `abordagens sociais e baseadas nas `networks de contactos ou redes locais dos clusters, bem como as teorias baseadas no conhecimento. Estudos sobre sistemas regionais e nacionais de inovação e abordagens institucionais (relativas a culturas, governação e costumes locais das regiões) alcançaram particular importância a partir da década de 1990. Isto reflecte claramente as mais recentes tendências da literatura sobre clusters, que têm dado especial enfoque a factores sistémicos e institucionais . Finalmente, não obstante a correlação positiva entre a qualidade das publicações e a investigação formal e experimental, a evolução da literatura sobre clusters continua a ser maioritariamente apreciativa e descritiva. / As the global paradigm became an accepted reality, the local dimension has gained particular interest as an object of analysis. This is because key factors of global competitiveness have become deeply rooted at a local level. In this context, clusters, as geographical and socio-relational entities with a specific evolutionary path, institutional embeddedness and local knowledge dynamics, have become crucial elements in regional development, assuming a significant role in public policies. Despite its growing importance, the concept of cluster has been subject to a rather discretionary use in terms of interpretation and meaning. Since the multiplicity of definitions has flourished with the historical evolution of the cluster concept, it became necessary to find a way to organize the existing literature, in an attempt to overcome this multitude of notions and meanings. This dissertation aims to systematize the existing corpus of theoretical approaches and empirical studies on clusters by carrying out a thorough, qualitative survey of the cluster literature, complemented with a comprehensive bibliometric account, based on articles published in journals indexed in the Econlit and EBSCO bibliographic databases, from 1962 to 2007. The main outcomes of this research show that besides their importance in academic fields, the role of clusters has also been widely acknowledged in political spheres. Along with an increasing interest in the `local dimension, an emergent corpus of literature on global networks and clusters has also arisen. Moreover, behind the recent boom in the cluster literature is the influence of the prominent themes `local networks and social approaches and `knowledge-based theories . Studies on `regional and national innovation systems and `institutional approaches (mostly concerned with enrooted local cultures, governance and customs) have been achieving a particular importance since the 1990s. This clearly reflects the most recent trends in the cluster literature, which focus particularly on `systemic and `institutional factors. Finally, despite the positive correlation between the `quality of journals and related formal research, the evolution of the literature on clusters continues to be mostly appreciative-led.

Staphylococcus aureus is the leading cause of infective endocarditis in the United States. Infective endocarditis (IE) is defined as an infection of the endocardium, typically involving the heart valves. The hallmark features of IE are vegetations. Vegetations are cauliflower-like, stratified biofilms of bacteria and host factors that develop on the valve leaflets of the heart. The mechanisms of how vegetations form are not well understood, and as a consequence the bacterial factors that are important for development of IE are not well defined. My studies focus on the role of a family of S. aureus exoproteins known as superantigens and their role in IE. Superantigens (SAgs) are a class of secreted virulence factors that have been extensively studied for their role in systemic diseases such as toxic shock syndrome (TSS), pneumonia, and food poisoning. The SAg protein family is comprised of 23 distinct members designated as staphylococcal enterotoxin (SE) or enterotoxin-like (SEl) and toxic shock syndrome toxin-1 (TSST-1). The term superantigen is derived from the ability of SAgs to interact with the immune system, resulting in a nearly 3000-fold increase in activation when compared to standard antigens. SAgs have a defined structure that is composed of 2 domains, a carboxy-terminal beta-grasp domain and amino-terminal oligosaccharide/oligonucleotide binding (OB) fold. Defined groups of SAgs are associated with S. aureus strains isolated from specific diseases, but few studies have been done to determine the role of SAgs in diseases outside of TSS and food poisoning. The enterotoxin gene cluster (egc) is a group of 6 SAgs (selo, selm, sei, selu, seln, and seg) assembled into an operon-like cluster that is present in the majority of S. aureus strains isolated from IE patients. My studies have determined that the egc is able to induce vegetations when expressed in avirulent S. aureus strains. This is the first time the egc has been directly associated with IE. I further characterized the capacity of the individual egc proteins to induce vegetations. Four (selo, selm, sei, and selu) of the 6 egc SAgs were able to induce vegetation formation. This is the first time the individual egc proteins have been characterized and directly associated with IE. I also demonstrated that the egc proteins may not be exclusively expressed as a single polycistronic transcript but that selu and seg contain promoter elements that may drive their individual expression. Lastly, I provide evidence that the egc SAgs may be regulated by MgrA, a global regulator of S. aureus associated with virulence factor expression.

No description available.

In non-relativistic quantum mechanics, stationary states of molecules and atoms are described by eigenvectors of the Hamiltonian operator. For one-electron systems, such as the hydrogen atom, the solution of the eigenvalue problem (Schro ̈dinger’s equation) is straightforward, and the results show excellent agreement with experiment. Despite this success, the multi electron problem corresponding to virtually every system of interest in chemistry has resisted attempts at exact solution. Perhaps the most popular method for obtaining approximate, yet very accurate results for the ground states of molecules is the coupled cluster approximation. Coupled cluster methods move beyond the simple, average field Hartree-Fock approximation by including the effects of excited configurations generated in a size consistent manner. In this paper, the coupled cluster approximation is developed from first principles. Diagrammatic methods are introduced which permit the rapid calculation of matrix elements appearing in the coupled cluster equations, along with a systematic approach for unambiguously determining all necessary diagrams. A simple error bound is obtained for the ground state energy by considering the coupled cluster equations as entries in the first column of a matrix whose eigenvalues are the exact eigenvalues of the Hamiltonian. In addition, a strategy is considered for treating the error in the ground state energy perturbatively.

Rapid population growth and climate variability have been posing pressure on groundwater management, especially in regions dominated by irrigation agriculture. Effective management practices require a better understanding of groundwater dynamics and its contributing factors, such as recharge, groundwater-surface water interactions, soil and unsaturated zone characteristics. Although groundwater models can provide valuable insights into these questions, these models are often nonexistent or cost prohibitive.