• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 288
  • 120
  • 26
  • 25
  • 20
  • 16
  • 15
  • 13
  • 4
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 653
  • 653
  • 653
  • 124
  • 106
  • 99
  • 86
  • 83
  • 82
  • 77
  • 73
  • 73
  • 68
  • 59
  • 50
  • 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.
111

Robust analysis of structural equation models with maximum likelihood and bayesian approaches. / CUHK electronic theses & dissertations collection

January 2005 (has links)
Latent variable models (LVMS) are widely appreciated multivariate methods to explore variables that are related to the observed variables, and assessing the relationships among them. One of most widely used latent variable models is structural equation model (SEM). Based on more than a dozen standard packages for fitting SEMs, such as LISREL VIII (Jorskog and Sorbom, 1996), and EQS (Bentler, 2004), these models have been widely appreciated in behavioral, educational, medical, social, and psychological research. The statistical theories and methods in these packages are based on the normal distribution; hence, they are vulnerable to outliers and the non-normal assumption. As outliers and non-normal data set are commonly encountered in substantive research, this fundamental problem has received much attention in the field. However, almost all existing methods are developed via the covariance structure analysis approach that heavily depends on the asymptotical properties of the sample covariance matrices S. Hence, this approach cannot be applied to the more complex SEMs and/or SEMs with more complex data structure such as missing data, because under these more complicated situations S is complicated, and its asymptotical properties are not well known. The objectives of this thesis are to develop novel robust methods for analyzing complex SEMs and/or more data structures, including but not limited to nonlinear SEMs with missing data. Both maximum likelihood (ML) and Bayesian approaches for estimation, hypothesis testing and model comparison will be investigated. Efficient algorithm for computing the results for statistical inference will be developed through unitization and modification of the advanced tools in statistical computing, for example the Monte Carlo Expectation-Maximization algorithm, and the Markov Chains Monte Carlo methods. Asymptotical properties of some statistics are derived. Simulation studies and real examples are conducted to reveal the empirical performance of the Bayesian and ML approaches. The newly developed methodologies will be very useful for analyzing complex data in the substantive research. / Xia Yemao. / "October 2005." / Adviser: S. Y. Lee. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3883. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 105-114). / 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. / Abstract in English and Chinese. / School code: 1307.
112

結構方程模型缺失數據處理方法. / Analytical strategies for structural equation models with missing data / CUHK electronic theses & dissertations collection / Jie gou fang cheng mo xing que shi shu ju chu li fang fa.

January 2010 (has links)
李晓煦. / Submitted: Jan. 2010. / Thesis (doctoral)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (p. 170-175). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in Chinese and English. / Li Xiaoxu.
113

Bayesian analysis of generalized latent variable models with hierarchical data.

January 2009 (has links)
Lam, Kwok Hap. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 68-72). / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Two-level NSEM with outcomes from Exponential Family --- p.6 / Chapter 2.1 --- Basic Model Description --- p.7 / Chapter 2.2 --- Generalization from Normal Distribution to Exponential Family Distributions --- p.9 / Chapter 2.3 --- Bayesian Analysis of the Model --- p.10 / Chapter 2.3.1 --- Posterior Analysis and Gibbs Sampler --- p.10 / Chapter 2.3.2 --- Prior Distributions --- p.11 / Chapter 2.3.3 --- Bayesian Estimation --- p.13 / Chapter 2.3.4 --- Bayesian Model Selection --- p.14 / Chapter 2.4 --- A Simulation Study --- p.15 / Chapter 3 --- Two-level NSEM with mixed continuous and ordered categorical data --- p.28 / Chapter 3.1 --- Model Description --- p.29 / Chapter 3.2 --- Bayesian Analysis of the Model --- p.30 / Chapter 3.2.1 --- Posterior Analysis and Gibbs Sampler --- p.30 / Chapter 3.2.2 --- Bayesian Estimation --- p.31 / Chapter 3.3 --- A Simulation Study --- p.31 / Chapter 4 --- "Two-level NSEM with mixed continuous, count and binomial data" --- p.36 / Chapter 4.1 --- Model Description --- p.37 / Chapter 4.2 --- Bayesian Estimation --- p.38 / Chapter 4.3 --- A Simulation Study --- p.39 / Chapter 5 --- Two-level NSEM with mixed continuous and unordered categorical data --- p.43 / Chapter 5.1 --- Basic Model Description --- p.44 / Chapter 5.2 --- Bayesian Analysis of the Model --- p.47 / Chapter 5.2.1 --- Posterior Analysis and Gibbs Sampler --- p.47 / Chapter 5.2.2 --- Prior Distributions --- p.48 / Chapter 5.3 --- A Simulation Study --- p.49 / Chapter 6 --- Conclusion and Discussion --- p.53 / Chapter A --- Technical Details for Chapter 2 --- p.56 / Chapter A.1 --- Full conditional distributions --- p.56 / Chapter A.2 --- Implementation of the Metropolis-Hastings (MH) Algorithm --- p.59 / Chapter A.3 --- Gelman-Rubin statistic --- p.61 / Chapter B --- Technical Details for Chapter 3 --- p.63 / Chapter B.1 --- Full conditional distributions --- p.63 / Chapter B.2 --- Implementation of the Metropolis-Hastings (MH) Algorithm --- p.64 / Chapter C --- Technical Details for Chapter 5 --- p.66 / Chapter C.l --- Full conditional distributions --- p.66 / Bibliography --- p.68
114

In search of diamond rules: Monte Carlo evaluations of goodness of fit indices.

January 2008 (has links)
Wang, Chang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 139-145). / Abstracts in English and Chinese. / ABSTRACT --- p.3 / CHINESE ABSTRACT --- p.5 / ACKNOWLEDGMENTS --- p.6 / TABLE OF CONTENTS --- p.7 / LIST OF TABLES --- p.9 / LIST OF FIGURES --- p.10 / INTRODUCTION --- p.11 / Chapter 1.1 --- ISSUE OF MODEL FIT IN SEM --- p.11 / Chapter 1.2 --- CLASSIFICATION AND DEVELOPMENT OF FIT INDICES --- p.13 / Chapter 1.3 --- ORGANIZATION OF THIS THESIS --- p.18 / Chapter CHAPTER 2 --- ISSUES OF FIT INDICES IN ASSESSING MODEL FIT --- p.19 / Chapter 2.1 --- SENSITIVITY OF FIS TO MODL PARAMETER --- p.19 / Chapter 2.1.1 --- Sample size --- p.20 / Chapter 2.1.2 --- Model complexity --- p.21 / Chapter 2.1.3 --- Misspecification --- p.23 / Chapter 2.2 --- MEASUREMENT ERROR --- p.26 / Chapter 2.3 --- PERFECT FIT VS. APPROXIMATE FIT --- p.26 / Chapter 2.4 --- Minimum Fit Function chi-square vs. Normal-theory Weighted Least chi-square --- p.29 / Chapter 2.5 --- RULE OF THUMB --- p.30 / Chapter 2.6 --- FIVE RESEARCH QUESTIONS --- p.37 / Chapter CHAPTER 3 --- SIMULATION --- p.39 / Chapter 3.1 --- FIT INDICES --- p.39 / Chapter 3.2 --- DESIGN OF MONTE CARLO SIMULATIONS --- p.38 / Chapter 3.3 --- MODEL COMPLEXITY AND MODEL SPECIFICATION --- p.39 / Chapter 3.4 --- SIMULATION PROCEDURE --- p.41 / Chapter CHAPTER 4 --- RESULTS --- p.45 / Chapter 4.1 --- MEASUREMENT ERROR AND CRONBACH´ةS ALPHA --- p.45 / Chapter 4.2 --- ANSWER TO Q1 --- p.45 / Chapter 4.3 --- ANSWER TO Q2 --- p.53 / Chapter 4.4 --- ANSWER TO Q3 --- p.56 / Chapter 4.5 --- ANSWER TO Q4 --- p.60 / Chapter 4.6 --- ANSWER TO Q5 --- p.62 / Chapter CHAPTER 5 --- DUSCUSSION --- p.77 / Chapter 5.1 --- DUSCUSSION TO Q1 --- p.77 / Chapter 5.2 --- DUSCUSSION TO Q2 --- p.83 / Chapter 5.3 --- DUSCUSSION TO Q3 --- p.85 / Chapter 5.4 --- DUSCUSSION TO Q4 --- p.88 / Chapter 5.5 --- DUSCUSSION TO Q5 --- p.89 / Chapter CHAPTER 6 --- LIMITATION --- p.99 / Chapter CHAPTER 7 --- CONCLUSION --- p.101 / PREFERENCE --- p.139
115

Bayesian analysis of latent variable models. / CUHK electronic theses & dissertations collection

January 2009 (has links)
Pan, Junhao. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 121-135). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
116

Estratégias de internacionalização: um estudo sobre a influência dos fatores de riscos sobre a estratégia e objetivos estratégicos em empresas exportadoras brasileiras / Internationalization strategies: a study on the influence of risk factor on strategy and strategic objectives in brazilian exporting companies

Souza, Crisomar Lôbo de 28 March 2017 (has links)
O ambiente competitivo e globalização vem provocando mudanças nas estratégias das empresas, fomentando, muitas vezes, para um processo de internacionalização. As empresas procuram internacionalizar-se de acordo com seus objetivos estratégicos, traçando uma estratégia de internacionalização. Sair do seu ambiente para um país desconhecido significa que a empresa estará sujeita a correr certos riscos e, portanto, requer uma estratégia que avalie os riscos envolvidos para se estabelecer em um determinado país. O conhecimento desses riscos vai proporcionar a empresa mitigar ou mesmo eliminar os riscos envolvidos. Independente do processo de entrada em outro país, sempre haverá a questão do risco. Geralmente, quando uma empresa decide se internacionalizar, ela opta primeiro pelo processo de exportação, em que terá de lidar com vários tipos de risco em suas decisões gerenciais para alcançar seus objetivos estratégicos. Portanto, essa pesquisa foi feita com oitenta e quatro empresas exportadoras brasileiras, do estado de São Paulo, com faturamento de até 10 milhões de dólares listadas na Confederação Nacional da Indústria (CNI). O objetivo desse estudo foi entender como e quais riscos envolvidos na internacionalização de empresas exportadoras brasileiras exercem influência sobre a estratégia e objetivos estratégicos na internacionalização de empresas exportadoras. Para a análise da pesquisa, foi utilizada a técnica de modelagem de equações estruturais baseada em variância, na qual foi utilizada uma survey para coleta de dados. Foram geradas quatro hipóteses, três relacionadas ao risco e estratégia e uma relacionada à estratégia e ao risco. Como resultado, duas hipóteses foram confirmadas e, portanto, duas rejeitadas. Essa pesquisa contribui com o conhecimento científico, pois, além de verificar os riscos que influenciam na estratégia e objetivos estratégicos, ela traz a concepção de envolver riscos não somente financeiros, mas também do ambiente, do setor e da empresa na estratégia para a internacionalização. / The competitive environment and globalization has been provoking changes in the strategies of companies, often leading to an internationalization process. The companies seek to internationalize themselves according to their strategic objectives, to which a strategy of internationalization will be traced. Leaving your environment to an unknown country means that the company is subject to certain risks and therefore requires a strategy that assesses the risks involved in establishing itself in a particular country. Knowing these risks will enable the company to mitigate or even eliminate the risks involved. Regardless of the process of entry into another country, there will always be the issue of risk. Usually, when a company decides to internationalize, it opts for the first time through the export process, where it will have to deal with various types of risk in its managerial decisions to reach its strategic objectives. Therefore, this research was conducted with eighty-four Brazilian companies in the state of São Paulo, with sales of up to 10 million dollars listed in Confederação Nacional da Indústria (CNI). The objective of the study was to understand how and what risks involved in the internationalization of Brazilian exporting companies influence the strategy and the strategic objectives in the internationalization of exporting companies. But even this process depending on the intensity of export the company will be subject to risk because it is unknown to the host country. Therefore, this research was carried out with Brazilian export companies, whose objective was to investigate the influence of the risks involved in the internationalization of Brazilian exporting companies on the strategy of internationalization and strategic objectives. For the analysis of the research was used the technique of modeling of structural equations based on variance, where a survey was used to collect data. Four hypotheses were generated, three related to risk and strategy and one related to strategy and risk. As a result, two hypotheses were confirmed and therefore two rejected. This research contributes with scientific knowledge, because in addition to verifying the risks that influence the strategy and strategic objectives, it brings the concept of involving not only financial risks but also the risk of the environment, sector and the company in the strategy for internationalization.
117

Structural equation models : an application to Namibian macroeconomics

Haufiku, Stetson Homateni 31 January 2013 (has links)
Structural Equations Models (SEMs) are now widely used almost in every discipline of research. Most of the existing materials for the Namibian macroeconomic models are studies of the well documented time series approach. In this study, we provided a statistical approach on modelling the Namibian macroeconomics for the real and fiscal economic sectors using SEMs. The approach is based on testing the theoretical specification laid down by the Namibian Macroeconometrics Model (NAMEX) of 2004. The economic structure and relationships among the variables is evaluated by means of exploratory and confirmatory analysis and the results are congruent to the existing theory in terms of loading patterns. Between Maximum Likelihood (ML) and Generalized Least Square (GLS) estimation methods, we compared the discrepancy of parameter estimates under the commonly encountered problems of sample size, violation of underlying assumptions in the data as well as model misspecifications. GLS estimation methods seem to provide better goodness of fit indices under those conditions. We have also shown that the fiscal sector is not well represented by our SEM. We recommend further studies to employ sufficiently larger samples so that models are correctly specified.
118

Student Column: Evaluating a Theoretical Model of Indoor Tanning Using Structural Equation Modeling

Scott, Colleen, Hillhouse, Joel J., Turrisi, Rob 01 January 2014 (has links)
No description available.
119

Conceptualizing Blended Learning Engagement

Halverson, Lisa R. 01 July 2016 (has links)
Learner engagement, or the involvement of the student's cognitive and emotional energy to accomplish a learning task, has been called "the holy grail of learning" (Sinatra, Heddy, & Lombardi, 2015, p. 1) because of its correlations to academic achievement, persistence, and satisfaction. In the 21st century, learning will be increasingly "blended," combining face-to-face with computer-mediated instruction. Research is already exploring learner engagement in blended contexts, but no theoretical framework guides inquiry or practice. Developing models and measures of the factors that facilitate learner engagement is important to the advancement of the domain. This multiple-article format dissertation addresses the theoretical gap in research on learner engagement in blended settings. The first article reviews the existing literature on learner engagement, delineates a set of constructs most relevant to the contexts of blended learning, and proposes a theoretical framework for learner engagement in blended settings. The second article operationalizes and tests the proposed model of blended learning engagement using exploratory and confirmatory factor analysis. It creates and evaluates an end-of-course self-report measure of cognitive and emotional engagement. The unique factor structure of online and face-to-face indicators of learner engagement is clearly demonstrated in the results of this study.
120

AFFECT, MOTIVATION, AND ENGAGEMENT IN THE CONTEXT OF MATHEMATICS EDUCATION: TESTING A DYNAMIC MODEL OF INTERACTIVE RELATIONSHIPS

Hu, Shanshan 01 January 2018 (has links)
The present study tested the interactive model of affect, motivation, and engagement (Linnenbrink, 2007) in mathematics education with a nationally representative sample. Self-efficacy, self-concept, and anxiety were indicators of pleasant and unpleasant affect. Intrinsic and extrinsic motivation were indicators of mastery and performance approach. Persistence and cognitive activation were indicators of behavioral and cognitive engagement. The 2012 Programme for International Student Assessment (PISA) supplied a sample of 4,978 students from the United States for structural equation modeling. The results indicated that PISA data overall supported the interactive model. Specifically, PISA data completely supported the specification of the relationship between motivation and affect, largely supported the specification of the relationship between affect and engagement, but failed to support the specification of the relationship between motivation and engagement. Finally, PISA data largely supported the specification of the mediation effects of affect on the relationship between motivation and engagement.

Page generated in 0.1378 seconds