Lau Suk Yin Rebecca. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 111-117). / Abstracts in English and Chinese. / ABSTRACT (ENGLISH) --- p.i / ABSTRACT (CHINESE) --- p.iii / ACKNOWLEDGEMENT --- p.iv / TABLE OF CONTENTS --- p.v / LIST OF TABLES --- p.viii / LIST OF FIGURES --- p.ix / Chapter CHAPTER I --- INTRODUCTION --- p.1 / Chapter CHAPTER II --- LITERATURE REVIEW --- p.6 / Chapter 2.1 --- Definition of Mediating Effects --- p.6 / Chapter 2.2 --- Approaches to Mediational Analyses --- p.12 / Chapter 2.2.1 --- Correlation Approach --- p.13 / Chapter 2.2.2 --- Hierarchical Regression Approach --- p.17 / Chapter 2.2.3 --- SEM Approach --- p.39 / Chapter 2.3 --- Summary --- p.44 / Chapter CHAPTER III --- A TEST FOR THE SIGNIFICANCE OF MEDIATING EFFECTS IN SEM --- p.47 / Chapter 3.1 --- A Significance Test for the Mediating Effects with SEM --- p.48 / Chapter 3.1.1 --- Model without Mediating Effects --- p.48 / Chapter 3.1.2 --- Model with Full Mediation --- p.49 / Chapter 3.1.3 --- Model with Partial Mediation --- p.49 / Chapter 3.1.4 --- Model with Suppression --- p.50 / Chapter 3.2 --- Procedure for Testing the Significance of Mediating Effects in SEM --- p.50 / Chapter 3.3 --- Summary --- p.56 / Chapter CHAPTER IV --- MODEL COMPARISON IN SEM --- p.59 / Chapter 4.2 --- Testing the Significance of Mediating Effects with ΔFIs --- p.61 / Chapter CHAPTER V --- METHODOLOGY OF SIMULATION --- p.65 / Chapter 5.1 --- Resampling Space Generation --- p.65 / Chapter 5.2 --- Sample Generation and Method of Analysis --- p.67 / Chapter CHAPTER VI --- SIMULATION RESULTS AND DISCUSSION --- p.73 / Chapter 6.1 --- Simulation Results --- p.73 / Chapter 6.1.1 --- Variance Explained by Model Characteristics --- p.73 / Chapter 6.1.1.1 --- Variance Explained Under the Condition of No Mediation --- p.80 / Chapter 6.1.1.2 --- Variance Explained Under the Condition of Mediating Effects at 0.1 --- p.81 / Chapter 6.1.1.2.1 --- Variance Explained by Factor Loadings --- p.81 / Chapter 6.1.1.2.2 --- Variance Explained by Sample Size --- p.82 / Chapter 6.1.1.2.3 --- Variance Explained by Number of Items --- p.83 / Chapter 6.1.1.2.4 --- "Variance Explained by 2-Way Interactions of Factor Loadings, Sample Size and Number of Items" --- p.83 / Chapter 6.1.2 --- Correlation between FIs and ΔFIs --- p.84 / Chapter 6.2 --- Simulation Result Discussion --- p.88 / Chapter CHAPTER VII --- NUMERICAL EXAMPLE --- p.91 / Chapter 7.1 --- Testing Mediating Effects in a Model in Past Literature --- p.91 / Chapter 7.2 --- Summary --- p.94 / Chapter CHAPTER VIII --- DISCUSSION --- p.96 / Chapter 8.1 --- Limitations and Directions for Future Research --- p.101 / APPENDIX / Chapter APPENDIX I --- Syntax for Testing the Significance of Mediating Effects (Unconstrained Model) / Chapter APPENDIX II --- Syntax for Testing the Significance of Mediating Effects (Constrained Model) / Chapter APPENDIX III --- Syntax for Testing Full Mediation --- p.106 / Chapter APPENDIX IV --- "Syntax for Testing Mediating Effects in Model by Foley, Kidder & Powell (2002) (DV: Intentions to Leave) (Unconstrained Model)" --- p.107 / Chapter APPENDIX V --- "Syntax for Testing Mediating Effects in Model by Foley, Kidder & Powell (2002) (DV: Intentions to Leave) (Constrained Model)" --- p.108 / Chapter APPENDIX VI --- "Syntax for Testing Mediating Effects in Model by Foley, Kidder & Powell (2002) (DV: Perceived Career Prospects) (Unconstrained Model)" --- p.109 / Chapter APPENDIX VII --- "Syntax for Testing Mediating Effects in Model by Foley, Kidder & Powell (2002) (DV: Perceived Career Prospects) (Constrained Model)" --- p.110 / REFERENCES --- p.111

Leung Man-Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 37-41). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Basic concepts of survival data --- p.3 / Chapter 1.2 --- Missing Complete at Random (MCAR) --- p.8 / Chapter 1.3 --- Missing at Random (MAR) --- p.9 / Chapter 2 --- The maximaization of the marginal likelihood --- p.11 / Chapter 2.1 --- Survival function --- p.11 / Chapter 2.2 --- Missing covariate pattern --- p.13 / Chapter 2.3 --- Set of survival time with rank restrictions --- p.13 / Chapter 2.4 --- Marginal likelihood --- p.14 / Chapter 2.5 --- Score function --- p.15 / Chapter 3 --- The MCMC stochastic approximation approach --- p.17 / Chapter 4 --- Simulations Studies --- p.22 / Chapter 4.1 --- MCAR : Simulation 1 --- p.23 / Chapter 4.2 --- MCAR : Simulation 2 --- p.24 / Chapter 4.3 --- MAR : Simulation 3 --- p.26 / Chapter 4.4 --- MAR : Simulation 4 --- p.27 / Chapter 5 --- Example --- p.30 / Chapter 6 --- Discussion --- p.33 / Appendix --- p.35 / Bibliography --- p.37

Lai, Ka Lun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 75-77). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Multivariate Threshold Time Series Model --- p.14 / Chapter 2.1 --- The Multivariate TAR Models --- p.14 / Chapter 2.2 --- Testing for Nonlinearity --- p.15 / Chapter 2.3 --- Model Selection and Estimation --- p.22 / Chapter 2.4 --- Bivariate TAR Models --- p.26 / Chapter 2.5 --- Applications --- p.27 / Chapter Chapter 3 --- Comparative Study of Interest Rates --- p.34 / Chapter 3.1 --- Background --- p.34 / Chapter 3.2 --- The Importance of Modelling Interest Rates --- p.40 / Chapter 3.3 --- The Scope of Study --- p.41 / Chapter 3.4 --- Major Findings --- p.42 / Chapter Chapter 4 --- Conclusion --- p.71 / Reference --- p.80

No description available.

O sistema orçamentário é um artefato contábil relevante para a tomada de decisão diante de um contexto de alta complexidade apresentado na realidade contemporânea, pois representa uma antecipação da visão da empresa, traduzindo sua estratégia e oferecendo diretrizes de conduta. Sua composição e as razões para o seu uso (como forma de comunicação das metas, avaliando desempenho, sendo um instrumento de planejamento operacional e de formação da estratégia) parecem estar relacionadas às variáveis contingenciais que afetam a empresa, tais como a incerteza ambiental percebida, a estratégia em foco, a estrutura organizacional, a tecnologia empregada em seu sistema de informação e o seu porte. O presente estudo, portanto, possui como finalidade compreender os atributos do sistema orçamentário a partir das variáveis contingenciais, considerando determinados níveis de desempenho. Metodologicamente, trata-se de um estudo descritivo e causal, utilizando-se de coleta de dados com questionário previamente formulado, aplicado para os controllers ou responsáveis pela controladoria nas indústrias paranaenses cadastradas em 2006 na FIEP- Federação das Indústrias do Estado do Paraná. Adicionalmente, refere-se a um estudo ex post facto, em condições de campo, transversal e utilizando-se de técnicas estatísticas de análise multivariada, mais especificamente testes não-paramétricos, correlação de Pearson, análise fatorial, modelagem de equações estruturais e clusters. Por subsidiar sua investigação com a abordagem contingencial, o presente estudo pode ser caracterizado como sendo uma pesquisa de sistemas, relacionando as diversas variáveis em análise com o desempenho percebido para a identificação de arranjos contingenciais. Os resultados apresentados apontam para a aceitabilidade das cinco hipóteses apresentadas na tese, ratificando a influência do ambiente nos fatores contingenciais intra-organizacionais, a relação dos fatores contingenciais e o sistema orçamentário da empresa, a influência das variáveis contingenciais no desempenho, a associação existente entre os atributos orçamentários e o desempenho e, por fim, a presença de arranjos (fits) entre as variáveis contingenciais e os atributos do sistema orçamentário, em virtude da apresentação de um desempenho superior. A presente pesquisa empírica revela que independente do porte, indústrias paranaenses que possuem um maior grau de aderência ao sistema orçamentário, conscientes das razões para o seu uso e que apresentam tarefa rotineira em seus processos exibiram alto desempenho organizacional e orçamentário. Logo, conclui-se que sob certas condições há indícios que o orçamento é benéfico à empresa, revelando uma relação custo-benefício positiva. / The budgetary system is a relevant accounting tool to the decision-making within the high complex context of the contemporary reality, since it represents a prospect of the business vision, translating its strategy and offering conduct guidance. The budgetary system\'s composition and the reasons for its use (as a form of targets communication, performance evaluation and being an instrument for operational planning and strategic formation) seem to be related to contingent variables that affect a business, such as perceived environmental uncertainty, focus strategy, the organizational structure, the information system technology employed and its size. The present study, therefore, intends to understand the budgetary system attributes considering contingent variables and certain performance levels. Methodologically, it is a descriptive and causal study, witch uses data from previously formulated surveys, aimed to the controllers or to the responsible for the control department of the Paraná industries registered at FIEP - Federação das Indústrias do Estado do Paraná in 2006. Additionally, it is an ex post facto study, in field conditions, transversal, and using multivariate analysis statistical techniques, more specifically non parametric tests, Pearson correlation, factorial analysis, structural equation modeling, and clusters. Since this investigation is subsidized by a contingent approach, it may be characterized as a systems\' research, relating the many variables under analysis like the noticed performance of contingent arrangements/fits. The presented results show an acceptability of the five hypotheses presented on the thesis, ratifying the environment influence on the intraorganizational contingent factors, the relations between the contingent factors and the company budgetary system, the contingent variables influence on the performance, the existent association between the budgetary attributes and the performance and, finally, fits/arrangements presence between the contingent variables and the budgetary system attributes, due to the better performance presentation. This empirical research reveals that unrelated to the company size, Paraná industries that show a higher degree of adherence to the budgetary system, industries that are conscious of the reasons for its uses and present routine tasks in its process showed an organizational and budgetary high performance. Thus, the conclusion is that under certain conditions the budgeting is a benefit to the company, revealing a positive cost-benefit relation.

Global Climate Change has empirical evidence to support the idea that CO2 levels may be affecting weather and health, including rates of infectious diseases. The Midwest region of the United States of America has had the highest increase in giardiasis rates in recent years, and Missouri was chosen for this study as a representative state in the Midwest. There is no definitive answer as to why the rates of giardiasis have changed from 2003 - 2013. The Theory of Climate Change was used as the theoretical framework for this study. The purpose of this research was to determine whether temperature, precipitation and CO2 levels are associated with giardiasis. A cross-sectional design was used for this study with a non-probability sample of reported cases of giardiasis for 2003 - 2013, and data were analyzed using a bivariate analysis and multivariate analysis. There was a negative association between precipitation and number of cases of giardiasis in Missouri residents (p < .05), a positive association between temperature and number of cases of giardiasis in Missouri residents (p < .05), and a positive association between CO2 levels and number of cases of giardiasis in Missouri residents (p < .05). Levels of CO2 modified the association between precipitation and number of cases of giardiasis in Missouri residents (p < .05). Levels of CO2 modified the association between temperature and number of cases of giardiasis in Missouri residents (p < .05). These results demonstrate that climatic factors impact public health significantly. The implications for social change are to have the waterways, wells, and public water tested more often, to reinforce the waterway closures with increased measures to prevent morbidity and mortality with giardiasis when possible, and to raise awareness of the climatic impact on health.

Students' retention in STEM-related careers is of great concern for educators and researchers, especially the retention of underrepresented groups such as females, Hispanics, and Blacks in these careers. Therefore it is important to study factors that could potentially influence students' decision to stay in STEM. The work described in this dissertation involved three research studies where assessments have been used in college chemistry courses to assess students' prior content knowledge, chemistry-self-efficacy, and attitude toward science. These three factors have been suggested to have an influence on students' performance in a course and could eventually be a retention factor. The first research study involved the development and use of an instrument to measure biochemistry prior knowledge of foundational concepts from chemistry and biology that are considered important for biochemistry learning. This instrument was developed with a parallel structure where three items were used to measure a concept and common incorrect ideas were used as distractors. The specific structure of this instrument allows the identification of common incorrect ideas that students have when entering biochemistry and that can hinder students' learning of biochemistry concepts. This instrument was given as pre/posttest to students enrolled in introductory biochemistry courses. The findings indicated that some incorrect ideas are persistent even after instruction, as is the case for bond energy and the structure of the alpha helix concepts. This study highlights the importance of measuring prior conceptual knowledge; so that instructors can plan interventions to help students overcome their incorrect ideas. For the second research study, students' chemistry self-efficacy was measured five times during a semester of preparatory college chemistry. Chemistry self-efficacy beliefs have been linked to students' achievement, and students with stronger self-efficacy are more likely to try challenging tasks and persist in them, which will help them to stay in STEM. Using multilevel modeling analysis to examine potential differences in students' self-efficacy beliefs by sex and race/ethnicity, it was found that there were some differences in the trends by race/ethnicity. In particular, we found that for Hispanic and Black males the trends were negative when compared with White males. This study highlights the importance of measuring self-efficacy at different time points in the semester and for instructors to be aware of potential differences in their students' confidence when working on a chemistry task. The third research study involves the use of the Test of Science Related Attitudes (TOSRA) in an introductory chemistry course. A shortened version of the instrument that includes three scales, normality of scientists, attitude toward inquiry, and career interest in science was used. The first purpose of this study was to gather validity evidence for the internal structure of the instrument with college chemistry students. Using measurement invariance analysis by sex and race/ethnicity, it was found that the internal structure holds by sex, but it did not hold for Blacks in our sample. Further analysis revealed problems with the normality scales for Blacks. The second purpose was to examine the relationship between the scales of TOSRA, achievement in chemistry, and math prior knowledge. Using Structural Equation Modeling (SEM) it was found that two of the TOSRA scales, attitude toward inquiry and career interest in science, have a small but significant influence on students' achievement in chemistry. This study highlights the importance of examining if the scores apply similarly for different group of students in a population, since the scores on these assessments could be used to make decisions that will affect student. The research studies presented in this work are a step forward with our intention to understand better the factors that can influence students' decisions to stay or leave STEM-related careers. Each study has provided psychometric evidence for the use of three different assessments in college chemistry courses. Instructors can use these assessments in large and small lecture classrooms. Information obtained from these assessments can then be used to make target interventions to help students learn and/or be more confident on a given task. Also, it highlights the importance to look at different group of students, such as the underrepresented groups, since response trends may be different. Being aware of students' diverse needs will help us to understand some of the challenges that student face in the chemistry classroom. Understanding some of these challenges will help instructors be more prepared for teaching.

Abstract not available

The operation of a chemical process plant has become more complex with the addition of process integration and intensification. A greater emphasis on producing goods with the lowest product variability in the safest manner possible and stringent environmental regulation limiting the quantity of effluent release have all put more constraints on the physical and economic performance of the chemical plant. The performance of a plant is quantified by the ability of the process system to achieve its objectives, which is governed by its process design and control. The conventional approach to process design and control selection starts sequentially by proposing a process flowsheet for the plant. The selection criteria for a flowsheet are normally based only on its environmental impact and economic merits. It is after a process flowsheet is deemed financially suitable that process control development commences. However, a more integrated approach to process design and control stage may thus lead to a plant that has better achievable performance. The aim of this project is to provide a new approach to quantitative dynamic controllability analysis for integration of process design and control by using the concept of passivity and passive systems. Passivity is an input/output property of processes. Passive processes are stable and minimum phase and therefore very easy to control. For a given process, its shortage of passivity, which reflects destabilizing effects of factors such as time delays and Right-Half Plane (RHP) zeros, can be used to indicate its controllability. The project focuses in developing the proposed controllability analysis by combining the idea of passivity and IMC invertibility, which is then formulated into an optimization problem that can be solved by either using Semi-Definite Programming or Non-Linear Optimization. The achievable performance of the plant is quantified in terms of the sensitivity function of the open-loop process. The selection of a process from four different heat-integrated distillation column schemes was used as a case study and the result had clearly shown that the passivity-based controllability analysis was able to select a process based on the plant achievable performance under the constraint of passivity and design parameters.

Graduation date: 1994