Dissertation submitted to the Department of Psychology, University of the Witwatersrand, in fulfilment of the requirements for the degree of Master of Arts. / The aim of the present study was to develop and evaluate a process model linking stressful environmental change, perceived job insecurity and stress reactions, A review of the literature revealed that stressful changes in the environment are linked to individual stress reactions, Stress theory has also recognised that appraisal of a stressful situation leads to stress reactions, Moreover, the literature has identified job Insecurity as a form of appraisal in that it is an internal event reflecting a transformation of beliefs about what 's happening in the organisation and environment. Job insecurity in turn has been shown to result in various stress reactions in individuals, Based on such research and theorising, a causal model was developed and tested using structural equation modeling techniques, It was assessed whether: stressful environmental change impacted upon stress reactions and job insecurity; job insecurity impacted upon stress reactions; and whether Job insecurity operated as a form of appraisal in mediating the relationship between stressful environmental change and stress reactions, The Independent variable, stressful environmental change, was specified as a common factor of the measured variables, political change, social change and organisational change, The proposed mediator variable, job insecurity, was specified as a common factor of the measured variables perceived threat to total job multiplied by powerlessness, and perceived threat to job features multiplied by powerlessness, The dependent variable, stress reactions, was specified as a common factor of the measured variables psychological distress, job dissatisfaction and reduced organisational commitment. The model was tested empirically using a combined sample of 267 subjects from three organisations, Results indicated that all relationships In the proposed model were confirmed, and that a reasonable fit was demonstrated between the empirical data and the theoretical model. Stressful environmental change was causally related to both stress reactions and Job insecurity, Job Insecurity was causally related to stress reactions, and in addition operated as a partial mediator between stressful environmental change and stress reacdons. Conceptual and methodological reasons for the findings are discussed, as well as some theoretical and practical implications, Limitations in the methodology are identified and future considerations of research are suggested, / AC2017

This thesis aims to provide clarity on which factors within an organization positively affect its performance in terms of innovation.  Innovation is seen as a critical component of a company’s strategy in achieving market differentiation and profitability, yet for many, it remains a frustrating pursuit.  This study aims to empirically model the relationship between a firm’s investment in innovation and the effect of this investment on its performance.  The method used is Structural Equation Modeling with data gathered from our online survey of 128 respondents from firms within the EU.  This work addresses two research questions, the first being to confirm that a firm’s innovation performance is influenced by both a commitment to human factors focusing on softer values in combination with strong R&D and technical capability.  Secondly, whether the presence of innovation inhibitors influences this relationship.  The findings showed that a firm’s innovation performance is improved when it prioritizes creating an environment and culture that nurtures innovation only when activated through a strong commitment to technical and R&D excellence, but not without this technical capacity.  Secondly, the introduction of innovation inhibitors reconfirmed the first finding, and the relationship between both the human factors within a company and its technical capability, as well as the relationship between this technical capability and its performance was stronger in their presence.

<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.

中介效應和調節效應分析在心理學研究中廣泛存在。調節效應發生時，自變量和因變量的關係的強度或方向會因調節變量的水平而有所改變。另一方面，中介效應發生時，自變量會通過中介變量對因變量來產生影響(Baron& Kenny,1986) 。心理學家經常結合這兩種效應以處理更複雜的問題，例如:調節作用是如何發生或中介作用在什麼情況會有所改變。研究學者定義前者為有中介的調節作用，後者為有調節的中介作用。儘管在文獻中有許多關於中介的調節效應和有調節的中介效應的分析方法的討論，對於理解這兩種效應的混亂仍然存在。此外，結構方程模型分析方法雖然比傳統的迴歸分析方法更靈活和有效地處理這兩種效應的分析，但是文獻上卻甚少討論如何應用結構方程模型於有中介的調節作用和有調節的中介作用的分析上。本論文回應以上提出的問題，主要討論如何把結構方程模型的分析方法應用在有中介的調節效應和有調節的中介效應的分析上，論文的第一部份會透過闡明五種常見有關於有中介的調節效應和有調節的中介效應的概念模型以消除研究橕者對這兩種效應定義的誤解。在論文的第二部分將會提出一個用以轉換有中介的調節效應和有調節的中分效應的概念模型為能應用於結構方程模型分析法上的模型的統一方法，讓研究學者能統一方法中提出的規則簡易地把假設模型變成為可為結構方程模型作分析的模型。模擬實驗來比較迴歸方法和結構方程模型方法的實際效用。結果顯示，這兩種分析方法發現相近。論文最後的部份，引人用於潛變量調節作用分析上的unconstrained indicant product approach (Marsh et al., 2004) ，並結合本文提出的統一方法來分析有中介的調節作用和有調節的中介作用，模擬實驗結果顯示這種方法在大多數的模擬情況下表現令人滿意。然而，以評估模型擬合度的卡方檢定在模擬實驗的大多數情況中都並不準確，因此研究學者應謹慎處理卡方檢定。 / Moderation and mediation analyses are widespread in psychological research. Moderation occurs when the direction and/or strength of the relation between an independent variable and a dependent variable depends on the level of a moderating variable. Mediation, on the other hand, occurs when the effect of an independent variable on a dependent variable is transmitted through a mediating variable (Baron & Kenny, 1986). Psychologists often move beyond these two processes and ask more complex questions such as how a moderating effect takes place or when a mediating process varies in different contexts. The former question has been referred as mediated moderation while the latter one has been referred as moderated mediation. Despite the fact that there are many discussions about the analysis of mediated moderation and moderated mediation in the literature, the confusion over the interpretation of these two processes persists. In addition, the SEM method, which is known to be more flexible than traditional egression method for the analysis of mediated moderation and moderated mediation is rarely discussed in the literature. In response to these issues, the main objective of the present study was to examine the methods for the analysis of mediated moderation and moderated mediation in the SEM framework. The first part of this study resolved the confusion over the current interpretation of the mediated moderation and moderated mediation by demonstrating these two processes using five typical conceptual models of mediatedmoderation and moderated mediation. In the second part, a new unified method was proposed to provide some general rules for translating the conceptual models of mediated moderation and moderated mediation into the SEM working models. The empirical performance of SEM analysis against regression analysis was assessed by a simulation study. Results showed the two methods performed similarly across different model conditions. In the last part, the unconstrained indicant product approach (Marsh, et al., 2004) for latent moderation analysis was introduced and combined with the unified approach for the analysis of latent variable mediated moderation and moderated mediation models. Simulation findings suggested that this method performed satisfactorily for testing mediated moderating and moderated mediating effects in most simulation conditions. However, chi-square statistics for the evaluation of model fit should be used with cautious as simulation results indicated that they were not accurate in most cases. / Detailed summary in vernacular field only. / Kwan, Lok Yin. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 104-114). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / ACKNOWLEDGEMENT --- p.iii / ABSTRACT --- p.v / CHINESE ABSTRACT --- p.vii / TABLE OF CONTENTS --- p.ix / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Moderation --- p.2 / Mediation --- p.2 / Moving Beyond Moderation and Mediation --- p.4 / Objectives of This Study --- p.6 / Outline of the Following Chapters --- p.8 / Chapter CHAPTER 2 --- MEDIATED MODERATION AND MODERATED MEDIATION --- p.10 / Mediated Moderation --- p.11 / Moderated Mediation --- p.13 / Critical Issues Related to the Current Interpretations --- p.14 / Moderated Mediation within a Mediation Context --- p.19 / Mediated Moderation within a Moderation Context --- p.21 / Summary of This Chapter --- p.25 / Chapter CHAPTER 3 --- ANALYSIS OF MEDIATED MODERATION AND MODERATED MEDIATION --- p.27 / Models --- p.27 / Regression-based Methods --- p.33 / Structural Equation Modeling Approach --- p.39 / A Unified Approach for Model Specification in SEM --- p.42 / Regression-based Method Versus SEM Approach --- p.49 / Chapter CHAPTER 4 --- SIMULATION STUDY 1: REGRESSION-BASED VERSUS SEM-BASED METHODS --- p.51 / Design of the Simulation Study --- p.51 / Procedure --- p.54 / Results --- p.55 / Discussion and Conclusion --- p.63 / Chapter CHAPTER 5 --- LATENT VARIABLES MEDIATED MODERATION AND MODERATED MEDATION --- p.68 / Unconstrained Indicant Product Approach --- p.69 / Model Specifications of Latent meMO and moME Models --- p.76 / Simulation Study 2: Methods --- p.83 / Simulation Study 2: Results --- p..88 / Discussion and Conclusion --- p.94 / Chapter CHAPTER 6 --- CONCLUSION AND FUTURE DIRECTION --- p.97 / Practical Significance of This Study --- p.98 / Limitations and Future Direction --- p.99 / REFERENCES --- p.104 / ENDNOTES --- p.115 / LIST OF TABLES --- p.117 / TABLES --- p.119 / FIGURE CAPTION --- p.153 / FIGURES --- p.154

"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. "

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.

Radical changes to present day power systems will lead to power systems with a significant penetration of renewable energy sources and smartness, expressed in an extensive utilization of novel sensors and cyber secure Information and Communication Technology. Although these renewable energy sources prove to contribute to the reduction of CO2 emissions into the environment, its high penetration affects power system dynamic performance as a result of reduced power system inertia as well as less flexibility with regards to dispatching generation to balance future demand. These pose a threat both to the security and stability of future power systems. It is therefore very important to develop new methods through which power system security and stability can be maintained. This research investigated the development of methods through which the contributions of on-load tap changing transformers/transformer clusters could be assessed with the intent of developing real time adaptive voltage controlled demand response schemes for power systems. The development of such a scheme enables more active system components to be involved in the provision of frequency control as an ancillary service and deploys a new frequency control service with low infrastructural investment, bearing in mind that OLTC transformers are already very prevalent in power systems. In this thesis, a novel online adaptive supervisory controller for ensuring optimal dispatch of voltage-controlled demand response resources is developed. This novel controller is designed using the assessment results of OLTC transformer impacts on steady-state frequency and was tested for a variety of scenarios. To achieve the effective performance of the adaptive supervisory controller, the extensive use of statistical techniques for assessing OLTC transformer contributions to voltage controlled demand response is presented. This thesis also includes the use of unsupervised machine learning techniques for power system partitioning and the further use of statistical methods for assessing the contributions of OLTC transformer aggregates.