[pt] Nesta pesquisa procurou-se estimar a qualidade da governança praticada por uma amostra significativa de companhias abertas brasileiras, no período entre 2002 e 2006, e relacioná-la aos indicadores precedentes do valor das companhias, que são o risco e o desempenho, de modo a verificar a existência de relações estatísticas significativas entre estas. Para mensurar a qualidade da governança construiu-se um índice composto por vinte perguntas de respostas binárias. Foram utilizados diversos indicadores para o risco como beta local; o beta obtido com o uso do S&P 500; a volatilidade; o risco idiossincrático, e o custo implícito do capital. Para mensurar o desempenho foram utilizadas as variáveis roa (return on assets); roe (return on equity); ets (a margem ebit-to- sales), e o mts (o indicador de valor market-to-sales). Os resultados conseguidos por meio da aplicação do método das regressões lineares simples e múltiplas, em nível crescente de complexidade, são confirmados com robustez pelos resultados obtidos com o uso do método das equações estruturais, e confirmam as hipóteses iniciais. A investigação da endogeneidade da variável governança sugere que esta variável tem caráter endógeno em relação ao risco e à margem. Porém, o teste de Granger não mostra evidências de relação de causalidade originada das variáveis de risco e desempenho na governança, mas revela indícios de relação originada da governança nas variáveis retromencionadas. Os efeitos da possível endogeneidade não prejudicaram os resultados obtidos por meio das regressões lineares. Também se investigou a relação entre subíndices e as variáveis de risco e desempenho. Os resultados confirmam a influência dos subíndices relacionados com a estrutura de propriedade, a transparência e a atuação da administração da companhia no risco e desempenho das empresas. Não se observou relação estatística significativa entre o subíndice relacionado com a política de relacionamento com o investidor e as variáveis risco e desempenho. Por último, constatou-se que a maior dispersão do capital ordinário; a maior participação do controlador no capital total; menores graus de imobilização; maiores conselhos; menor alavancagem operacional e financeira; menores riscos; maiores margens; adoção de programa de ADR níveis 2 ou 3; maior tempo de experiência societária; maiores patrimônios, e a participação no Nível 2 ou Novo Mercado da Bovespa se relacionam positivamente com a qualidade da governança praticada pelas empresas. / [en] This study estimated the quality of governance practiced by a significant sample of Brazilian publicly traded companies between 2002 and 2006, and related it to risk and performance. An index composed of twenty questions, with all answers in binary form, was constructed to measure the quality of governance. Several indicators were used for risk such as the local beta, the beta obtained with the use of the S & P 500 index, share price volatility, idiosyncratic risk and the implicit cost of capital. Measures of performance were the following variables: return on assets), return on equity, the margin of ebit-to- sales, and the ratio of market value-to-sales). The results obtained through the application of the method of simple and multiple linear regressions, in increasing level of complexity, were confirmed, with robustness, by the results obtained by the use of structural equations, confirming the original hypotheses. The investigation of the endogeneity of the variable for governance suggests that this variable has an endogenous character in relation to the risk and margin. Though the test of Granger shows no evidence of a causal relationship between the variables of risk and performance in governance, it shows signs of a causal relationship caused by governance on the variables of risk and performance. The effects of possible endogeneity do not harm the results obtained using the linear regressions. The relationships between sub-indexes of governance and risk and performance were also investigated. The results confirm the influence of the sub-indexes of governance related to the structure of ownership, transparency and administration of the company on the risk and performance of companies. There was no statistically significant relationship between the sub- index related to the politics of relationships with the investor and the variables risk and performance. Finally, it was found that the greater dispersion of holdings of ordinary shares, the greater investment by the controlling shareholder in total capital, lesser degrees of tangible assets, larger boards of directors, lower operating and financial leverage, lower risk, higher margins, the existence of a ADR level 2 or 3 program, more experience in been a public company, greatest volume of assets, and participation in the Level 2 or Bovespa`s New Market`s correlate positively with the quality of governance practiced by the Brazilian publicly traded companies.

Understanding the causal architecture underlying complex systems biology has a great value in agriculture production for the development of optimal management strategies and selective breeding. So far, most studies in this area use only prior knowledge to propose causal networks and/or do not consider the possible genetic confounding factors on the structure search, which may hide important relationships among phenotypes and also bias the resulting inferred causal network. In this dissertation, we explore many structural learning algorithms and present a new one, called PolyMaGNet (Polygenic traits with Major Genes Network analysis), to search for recursive causal structures involving complex phenotypic traits with polygenic inheritance and also allowing the possibility of major genes affecting the traits. Briefly, a multiple-trait animal mixed model is fitted using a Bayesian approach considering major genes as covariates. Next, posterior samples of the residual covariance matrix are used as input for the Inductive Causation algorithm to search for putative causal structures, which are compared to each other using the Akaike information criterion. The performance of PolyMaGNet was evaluated and compared with another widely used approach in a simulated study considering a QTL mapping population. Results showed that, in the presence of major genes, our method recovered the true skeleton structure as well as the causal directions with a higher rate of true positives. The PolyMaGNet approach was also applied to a real dataset of an F2 Duroc × Pietrain pig resource population to recover the causal structure underlying on carcass, meat quality and chemical composition traits. Results corroborated with the literature regarding the cause-effect relationships between these traits and also provided new insights about phenotypic causal networks and its genetic architectures in complex systems biology. / Compreender a arquitetura causal subjacente à sistemas biológicos complexos é de grande valia na produção agrícola para o desenvolvimento de estratégias de manejo e seleção genética. Até o momento, a maior parte dos estudos neste contexto utiliza apenas conhecimento prévio para propor redes causais e/ou não considera fatores de confundimento genético na busca de estruturas, fato que pode ocultar relações importantes entre os fenótipos e viesar inferências sobre a rede causal. Nesta tese, exploramos alguns algoritmos de aprendizagem de estruturas e apresentamos um novo, chamado PolyMaGNet (do inglês, Polygenic traits with Major Genes Network analysis), para buscar estruturas causais recursivas entre características fenotípicas poligênicas complexas e permitindo, também, a possibilidade de efeitos de genes maiores que as afetam. Resumidamente, um modelo misto de múltiplas características é ajustado usando abordagem Bayesiana considerando os genes maiores como covariáveis no modelo. Em seguida, amostras posteriores da matriz de covariância residual são usadas como entrada para o algoritmo de causação indutiva para pesquisar estruturas causais putativas, as quais são comparadas usando o critério de informação de Akaike. O desempenho do PolyMaGNet foi avaliado e comparado com outra abordagem bastante utilizada por meio de um estudo simulado considerando uma população de mapeamento de QTL. Os resultados mostraram que, na presença de genes maiores, o método PolyMaGNet recuperou a verdadeira estrutura do esqueleto, bem como as direções causais, com uma taxa de efetividade maior. O método é ilustrado também utilizando-se um conjunto de dados reais de uma população de suínos F2 Duroc × Pietrain para recuperar a estrutura causal subjacente à características fenotípicas relacionadas a qualidade da carcaça, carne e composição química. Os resultados corroboraram com a literatura sobre as relações de causa-efeito entre os fenótipos e também forneceram novos conhecimentos sobre a rede fenotípica e sua arquitetura genética.

<p>The power of positive attitudes toward science is that they influence science achievement by reinforcing higher performance. Interestingly, there continue to be gender disparities in attitudes toward science across many countries. Males generally have more positive attitudes toward science than females. Although most research related to attitudes toward science have been based on the Trends in International Mathematics and Science Study (TIMSS) Student Questionnaire, there remains a dearth of evidence validating the TIMSS science attitudes items and measurement equivalence across genders. </p><p>The goals of this research were as follows: (1) to build support for the structural validity of the TIMSS items, and (2) to investigate whether the instrument measures the same latent construct (attitudes toward science) across genders. The present study followed two steps of statistical analyses. As a first step, two modeling methods (confirmatory factor analysis and exploratory structural equation modeling) were conducted to identify the best-fitting model for the instrument. Second, after determining the model of choice, we tested several nested invariance models progressively. </p><p>This study found (1) the latent factor structure of the TIMSS items and (2) strong measurement invariance across genders. This result indicated that the instrument is well designed by the <i>a priori</i>specification and measures the same latent variable for both female and male students. This study provides support for the multidimensional approach to measuring science attitudes and shows the flexibility of ESEM over CFA by demonstrating that the ESEM approach provided better representation of the underlying factor structure. </p>

Com a necessidade de analisar dados cada vez mais complexos nas mais diversas áreas, surge também a necessidade de novas técnicas e novas modelagens. Nesse contexto, os Modelos de Equações Estruturais são uma evolução da análise de caminhos proposto por Wright (1921), que por sua vez, consegue captar as relações de causa e efeito entre diferentes tipos de variáveis. Este trabalho tem como objetivo abordar uma revisão em torno dessa técnica, com ênfase aos modelos recursivos que utilizam em sua maioria apenas variáveis observadas. A aplicação deste trabalho está fundamentada em um processo de simulação considerando assim, seis cenários com diferentes tipos de relações numa mesma estrutura. As médias das estimativas dos parâmetros no processo de simulação resultam em valores próximos aos valores verdadeiros. Por meio de figuras e gráficos, pode-se observar o comportamento dos parâmetros por meio do erro quadrático médio e boxplot. A análise foi realizada com a utilização do software R e programas implementados com pacote sem (FOX; WEISBERG, 2012) e programação apresentada no Apêndice deste trabalho. / With the increasingly need to analyze complex data in several areas, comes the need for new techniques and new models. In this context, the Structural Equation Modeling is an evolution of the path analysis proposed by Wright (1921), which, can capture the relations of cause and effect between different types of variables. The present work aims to approach a review about this technique with emphasis on recursive models using mostly observed variables only. The application of this work is based on a simulation process considering six scenarios with different types of relationships within the same structure. The mean estimates of the parameters in the simulation result in values that are close to the true values, and by means of figures and graphs, one can observe the behavior of the parameters by means of the mean squared error and boxplot. The analysis was performed using the software software R and implemented programs as sem package (FOX; WEISBERG, 2012) and the programming is presented in the Appendix of this work.

Keywords: Latent variables, Ordered categorical data, Unordered categorical data, Nonignorable missing data, Maximum likelihood approach, Bayesian approach. / Structural equation models (SEMs) have been widely applied to examine interrelationships among latent and observed variables in behavioral, psychological, and medical research. Motivated by the fact that correlated ordered and unordered categorical variables are frequently encountered in practical applications, a nonlinear SEM that accommodates fixed covariates, mixed continuous, ordered categorical, and unordered categorical variables is proposed. Maximum likelihood methods for estimation and model comparison are discussed. Besides, missing data are frequently encountered in practical researches; a lot of attention has been devoted to analyze various SEMs with missing data. Bayesian analysis, including parameter estimate and model comparison, of a nonlinear SEM with mixed continuous, ordered and unordered categorical variables, and nonignorable missing entries is also considered in the thesis. Simulation studies are conducted to reveal the performance of the proposed methods. Moreover, we apply our methodologies to analyze the real-life data set about cardiovascular disease. As none of the existing SEMs can simultaneously accommodate fixed covariates, mixed continuous, ordered and unordered categorical data, and missing data, this thesis offers a novel SEM to cope with more complex practical problems and develop maximum likelihood and Bayesian methods for obtaining results in estimation and model comparison. / Cai, Jingheng. / Advisers: Sik-Yum Lee; Xin-Yuan Song. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3584. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 76-82). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

"To satisfy the global energy demand while accommodating the rapidly increasing consumption rate in its domestic market, Saudi Arabia must develop and implement fuel efficiency programs in many sectors. Since transportation is a major contributor to fuel consumption and emission levels, introducing Hybrid Electric Vehicles (HEV) provides a viable solution to mitigate the current problems. However, existing studies on the diffusion of innovative vehicle technologies as well as on the understanding of the vehicle ownership and consumer behavior in Saudi Arabia are sparse. To fill this knowledge gap, I have aimed at developing an in-depth knowledgebase about general vehicle ownership and HEV ownership potential in particular for Saudi Arabia in my dissertation. I have achieved the research goal through a comprehensive online questionnaire that contains three different perspectives with each contributing a chapter in my dissertation. The first perspective provides a general understanding of the vehicle owners’ behaviors by analyzing over 600 questionnaire responses. It sheds light on the vehicle ownership determinants of the respondents that currently own vehicles as well as on respondents’ future vehicle purchase plans. This research perspective reveals the importance of vehicle price and seating capacity and points out that seating capacity is not necessarily defined by the household size in Saudi Arabia. As HEV is not yet available in the Saudi market, the next perspective applies the Theory of Reasoned Action (TRA) by analyzing 847 questionnaire responses to identify factors that might drive Saudis’ intention to adopt such technology. The results indicate that, while both subjective norm and attitude are significant in explaining the intention, subjective norm has three times stronger effect on adopting HEV than attitude. The last perspective contains a three-stage analysis to help identify the profiles of the most potential HEV early adopters and increase the chance for the relevant stakeholders to reach out to an effective range of consumers. Three characteristics of such adopters are identified: at least 35 years old, part of a larger household (more than 6 people), and owning more than one vehicle. "

As organizações estão expostas a uma quantidade e variabilidade cada vez mais crescente de informações. A capacidade de se antecipar às tendências e se adequar ao ambiente passa a ser, além de fonte de vantagem competitiva, fator necessário para a sobrevivência. Nessa realidade, organizações frequentemente apresentam dificuldades de leitura de seu ambiente e adaptação ao meio. Acredita-se na necessidade de desenvolvimento de uma capacidade interna da organização para que o monitoramento do ambiente se estabeleça, bem como análise de oportunidades, planejamento de ações de melhoria e reconfiguração da organização. Este estudo buscou verificar a relação da Inteligência - enquanto processo de monitoramento do ambiente - como uma Capacidades Dinâmica, e de como esta pode contribuir com a geração de vantagem competitiva. Criou-se um modelo de pesquisa, utilizando-se dos modelos de Rios (2010) e Teece (2014), relacionando os conceitos de Inteligência e Capacidade Dinâmicas, e estas com a Vantagem Competitiva. Por meio de um questionário, realizou-se uma Pesquisa Survey, onde coletaram-se respostas de funcionários e/ou sócio de empresas brasileiras, independente de porte ou segmento. Para análise, utilizou-se da Modelagem de Equações Estruturais, e foi possível demonstrar que a Inteligência influencia positivamente nas Capacidades Dinâmicas do sub-grupo Transforming, na Estratégia e na Vantagem Competitiva. Dessa forma o modelo desenvolvido, tendo apresentado boa confiabilidade e aderência, pode também ser validado. / Organizations are exposed to an increasing amount and variability of information. The ability to anticipate trends and adapt to the environment becomes, besides a source of competitive advantage, a necessary factor for survival. In this reality, organizations frequently present difficulties in reading their environment and adapting to them. We believe in the need to develop an internal capacity of the organization for the monitoring of the environment to be established, as well as analysis of opportunities, planning of actions of improvement and reconfiguration of the organization. This study sought to verify the relationship of Intelligence - as a process of monitoring the environment - as a Dynamic Capabilities, and how this can contribute to the generation of competitive advantage. A research model was created, using the models of Rios (2010) and Teece (2014), relating the concepts of Dynamic Intelligence and Capacity, and these with the Competitive Advantage. By means of a questionnaire, a Survey Research was conducted, where responses were collected from employees and / or partners of Brazilian companies, regardless of size or segment. For the analysis, it was used the Modeling of Structural Equations, and it was possible to demonstrate that the Intelligence influences positively in the Dynamic Capacities of the Transforming subgroup, in the Strategy and the Competitive Advantage. In this way the developed model, having presented good reliability and adhesion, can also be validated.

Este estudo teve por objetivo investigar, à luz das teorias de internacionalização de empresas, a forma de inserção no mercado externo das indústrias de calçados da cidade de Franca, Estado de São Paulo e as características determinantes do comportamento seu exportador. Foi elaborado um cadastro atualizado do setor e enviados questionários a todas as empresas de pequeno, médio e grande porte (208 indústrias). Desse total, 146 empresas responderam à pesquisa e foram aproveitados 117 questionários. A pesquisa foi respondida, em grande parte, por diretores e pelos principais executivos das empresas, que expressaram suas percepções em relação aos diversos aspectos do processo de internacionalização de suas indústrias. A investigação procurou identificar as características da empresa, do respondente, da equipe dirigente, da produção e da comercialização dos seus produtos, tanto no mercado interno como externo. Foram investigados ainda o grau de diferenciação do produto, a imagem do pólo produtivo, as expectativas sobre as vantagens do comércio internacional e a percepção de barreiras internas à exportação. Por último se verificou a forma utilizada para a inserção no mercado externo e o estágio atual dessas empresas no processo de internacionalização de suas atividades. Pode-se afirmar que as empresas da indústria calçadista francana seguem uma estratégia gradual de inserção no mercado internacional, em consonância com a literatura sobre o processo de internacionalização. Foram identificados também alguns determinantes do compromisso exportador, as estratégias utilizadas e as ações implementadas para penetração no mercado externo e sugerido um modelo da empresa exportadora da indústria calçadista francana. O que se depreende, é que as empresas que não exportam apresentam problemas internos relacionados à percepção da falta de capacidade de produção para atender ao mercado externo, à dificuldade em lidar com as diferenças lingüísticas e culturais e o desconhecimento geral de como exportar. Tudo isso aliado a uma visão até certo ponto distorcida dos benefícios que a internacionalização pode trazer para as empresas, do ponto de vista das oportunidades de crescimento e de diversificação dos produtos fabricados que o mercado externo oferece e da rentabilidade a ser obtida nas exportações. A percepção dos dirigentes é a de que falta a estas empresas, também, uma melhor qualidade e tecnologia na fabricação de seus produtos, que se reflete em menores preços de venda do que os praticados pelas empresas exportadoras. / The purpose of this study was to investigate, concerning the theories of internationalization of enterprises, the way the footwear industries from Franca, State of São Paulo, are inserted in the foreign market and the striking features of their export behavior. An up-to-date catalogue of the enterprises was developed and questionnaires were sent to all small, medium and large enterprises (208 industries). From those, 146 enterprises responded to the survey and 117 were suitable for the purposes. The survey was responded, in great part, by directors and by the principal executives of the enterprises, whom expressed their perceptions of many aspects of the internationalization process of their enterprises. The investigation meant to identify the characteristics of the enterprise, of the person responding the questionnaire, of the managing staff, and of the production and commerce of their products, both in the domestic and foreign markets. It was also investigated at what degree the product was different from those in the market, the image of the productive pole, the expectations over the advantages of international trade and the perception of domestic export barriers. At last, the methods used for inserting the enterprises in the foreign market were verified, as well as their current status in the process of internationalization. It can be stated that the footwear enterprises from Franca follow a strategy of gradual insertion in the international market. Some determinants of the export agreement, the strategies used and the actions taken in order to reach the foreign market were also identified and a model of an exporting footwear enterprise was suggested. What can be inferred is that the enterprises which do not export present internal problems related to the perception of the lack of production power to meet the foreign market needs, to the difficulties in dealing with the language and cultural differences and to the lack of know how in exports. All allied with a view a little distorted of the benefits the internationalization can bring to the enterprise, from the point of view of growth opportunities and of the variety of manufactured products that the foreign market offers and of the profitability that can be reached through exports. The perception of the directors is that there is a lack of better quality and technology in the manufacture of their products, which is reflected in prices lower than those of the exporting enterprises.

The purpose of this three-article dissertation is to explore the intersection of educational leadership, instructional technology, and culturally responsive education in pursuit of a new leadership framework called technology leadership for social justice. This dissertation employs three emerging methodologies, namely three-step latent class analysis (LCA), multilevel latent class analysis (MLCA), and meta-narrative review, to examine typologies of teachers and their perceptions of technology use and technology leadership with large-scale, quantitative data and to offer a conceptual framework of school and district technology leadership through a culturally responsive lens. The first study utilized latent class analysis (LCA) with the NCES Fast Response Survey System Teachers’ Use of Educational Technology in U.S. Public Schools, 2009 (FRSS 95) dataset (n=2,764) to identify four different types of technology-using teachers: Dexterous, Presenters, Assessors, and Evaders. I also found that teachers in low-income schools are more likely to be in the teacher subgroups that use technology in less impactful ways in the classroom. The second study used multilevel latent class analysis (MLCA) with the 2011-12 Texas School Technology and Readiness (STaR) Charts (n=6,935 schools in n=910 districts) to find three subgroups of teacher perceptions of technology leadership at the school level, High STaR Schools, Moderate STaR Schools, and Low STaR Schools, and four subgroups of teacher perceptions of technology leadership at the district level, Model STaR Districts, High STaR Districts, Moderate STaR Districts, and Low STaR Districts. I found that the Texas teachers in the school and district level subgroups with the lowest perceptions of technology leadership had the lowest student achievement outcomes and were more likely to serve students from historically minoritized backgrounds. The third study employed a systematic, meta-narrative review of the research literature exploring the intersection of technology, leadership, and culturally responsive education, integrating the findings from sixty studies into a conceptual framework of technology leadership for social justice. Each of the three dissertation articles explores the implications for the development of a more evidence-based, sociocultural conception of school and district technology leadership in research, policy, and practice.

<div>In the past several decades, the advent of high-throughput biotechnologies for genomics study provides appealing opportunities for us to understand the complex gene interaction inside biological systems, attracting many researches in constructing gene regulatory networks (GRNs). Motivated by the promise of the genetical genomics</div><div>study, our research group has recently focused on representing gene regulatory networks using structural equation models and further revealing system-wide gene regulations.This dissertation presents two recent works along this direction.</div><div><br></div><div><div>Firstly, we conducted thorough theoretical analysis of the recently proposed Two-Stage Penalized Least Squares (2SPLS) method for constructing large systems of structural equation models. We establish the estimation and prediction error bounds for results at both stages of 2SPLS as well as its variable selection consistency. Specically, a bounded eigenvalue assumption is imposed to ensure the consistency properties of the ^l2-penalized regressions at the first stage. At the second stage, the estimation and</div><div>variable selection consistency of the ^l1-penalized regressions are obtained by assuming a restricted eigenvalue condition and a variant of irrepresentable condition, which are both commonly employed in the current literature. We will show that the 2SPLS estimator works not only for fixed dimensions but also diverging dimensions which can grow to infinity with the sample size but at an appropriate rate.</div></div><div><br></div><div><div>Secondly, we developed a novel statistical method to identify structural differences between two cognate networks characterized by structural equation models. We</div><div>propose to reparameterize the model to separate the differential structures from common structures, and then design an algorithm with calibration and construction stages to identify these differential structures directly. The calibration stage serves to obtain consistent prediction by building the^l2 regularized regression of each endogenous</div><div>variables against pre-screened exogenous variables, correcting for potential endogeneity issue. The construction stage consistently selects and estimates both common and</div><div>differential effects by undertaking ^l1 regularized regression of each endogenous variable against the predicts of other endogenous variables as well as its anchoring exogenous</div><div>variables. Our method allows for easy parallel computation. Theoretical results are obtained to establish non-asymptotic error bounds of predictions and estimates at both stages. Our studies on simulated data demonstrated that the proposed method performed much better than independently constructing networks. A real data set</div><div>was analyzed to illustrate the applicability of our method.</div></div>