With the rapidly growing need for long-term decision making in the presence of stochastic future events, it is important to devise novel mathematical optimization tools and develop computationally efficient solution approaches for solving them. Two-stage stochastic programming is one of the powerful modeling tools that allows probabilistic data parameters in mixed integer programming, a well-known tool for optimization modeling with deterministic input data. However, akin to the mixed integer programs, these stochastic models are theoretically intractable and computationally challenging to solve because of the presence of integer variables. This dissertation focuses on theory, algorithms and applications of two-stage stochastic mixed integer (non)linear programs and it has three-pronged plan. In the first direction, we study two-stage stochastic p-order conic mixed integer programs (TSS-CMIPs) with p-order conic terms in the second-stage objectives. We develop so called scenario-based (non)linear cuts which are added to the deterministic equivalent of TSS-CMIPs (a large-scale deterministic conic mixed integer program). We provide conditions under which these cuts are sufficient to relax the integrality restrictions on the second-stage integer variables without impacting the integrality of the optimal solution of the TSS-CMIP. We also introduce a multi-module capacitated stochastic facility location problem and TSS-CMIPs with structured CMIPs in the second stage to demonstrate the significance of the foregoing results for solving these problems. In the second direction, we propose risk-neutral and risk-averse two-stage stochastic mixed integer linear programs for load shed recovery with uncertain renewable generation and demand. The models are implemented using a scenario-based approach where the objective is to maximize load shed recovery in the bulk transmission network by switching transmission lines and performing other corrective actions (e.g. generator re-dispatch) after the topology is modified. Experiments highlight how the proposed approach can serve as an offline contingency analysis tool, and how this method aids self-healing by recovering more load shedding. In the third direction, we develop a dual decomposition approach for solving two-stage stochastic quadratically constrained quadratic mixed integer programs. We also create a new module for an open-source package DSP (Decomposition for Structured Programming) to solve this problem. We evaluate the effectiveness of this module and our approach by solving a stochastic quadratic facility location problem. / Doctor of Philosophy / With the rapidly growing need for long-term decision making in the presence of stochastic future events, it is important to devise novel mathematical optimization tools and develop computationally efficient solution approaches for solving them. Two-stage stochastic programming is one of the powerful modeling tools that allows two-stages of decision making where the first-stage strategic decisions (such as deciding the locations of facilities or topology of a power transmission network) are taken before the realization of uncertainty, and the second-stage operational decisions (such as transportation decisions between customers and facilities or power flow in the transmission network) are taken in response to the first-stage decision and a realization of the uncertain (demand) data. This modeling tool is gaining wide acceptance because of its applications in healthcare, power systems, wildfire planning, logistics, and chemical industries, among others. Though intriguing, two-stage stochastic programs are computationally challenging. Therefore, it is crucial to develop theoretical results and computationally efficient algorithms, so that these models for real-world applied problems can be solved in a realistic time frame. In this dissertation, we consider two-stage stochastic mixed integer (non)linear programs, provide theoretical and algorithmic results for them, and introduce their applications in logistics and power systems. First, we consider a two-stage stochastic mixed integer program with p-order conic terms in the objective that has applications in facility location problem, power system, portfolio optimization, and many more. We provide a so-called second-stage convexification technique which greatly reduces the computational time to solve a facility location problem, in comparison to solving it directly with a state-of-the-art solver, CPLEX, with its default settings. Second, we introduce risk-averse and risk-neutral two-stage stochastic models to deal with uncertainties in power systems, as well as the risk preference of decision makers. We leverage the inherent flexibility of the bulk transmission network through the systematic switching of transmission lines in/out of service while accounting for uncertainty in generation and demand during an emergency. We provide abundant computational experiments to quantify our proposed models, and justify how the proposed approach can serve as an offline contingency analysis tool. Third, we develop a new solution approach for two-stage stochastic mixed integer programs with quadratic terms in the objective function and constraints and implement it as a new module for an open-source package DSP We perform computational experiments on a stochastic quadratic facility location problem to evaluate the performance of this module.

Markets increase social welfare by matching willing buyers and sellers. It is important to understand whether markets are fulfilling their societal purpose and are operating efficiently. The prevalence of spatial arbitrage in markets is an important indicator of market efficiency. The two essays in my dissertation study spatial arbitrage and the behaviors of arbitrageurs Electronic commerce can improve market efficiency by helping buyers and sellers find and transact with each other across geographic distance. In the first essay, we study the effect of two distinct forms of electronic commerce on market efficiency, which we measure via the prevalence of spatial arbitrage. Spatial arbitrage is a more precise measure than price dispersion, which is typically used, because it accounts for the transaction costs of trading across distance and for unobserved product heterogeneity. Studying two forms of electronic commerce allows us to examine how the theoretical mechanisms of expanded reach and transaction immediacy affect market efficiency. We find that electronic commerce reduces the number of arbitrage opportunities but improves arbitrageur’s ability to identify and exploit those that remain. Overall, our results provide a novel and nuanced understanding of how electronic commerce improves market efficiency. Studying arbitrageur strategies will help us understand how arbitrageur behaviors impact markets by increasing/reducing spatial arbitrage. In the second essay, we study specialization strategies of arbitrageurs. Arbitrageurs specialize on asset type and sourcing locations. We investigate the role of specialization and find that specialization affects both arbitrage profits and arbitrage intensity. Subsequently, we find that specialization strategies evolve over time and different groups of arbitrageurs adapt differently based on behavioral biases and environmental factors. Overall, our findings support the predictions of the adaptive markets hypothesis and help us understand antecedents such as capital, arbitrage intensity, etc. which affect the evolution of arbitrageur strategy.

Different researchers and governments globally have recognised the importance of entrepreneurship in economic growth and job creation. In addition, entrepreneurial activity is crucial, locally and globally. Furthermore, the Global Entrepreneurship Monitor (GEM) recognises the contribution of entrepreneurial activity to economic growth and measures it by means of the total early stage entrepreneurial activity index (TEA). Since the TEA in South Africa is very low, the need exist for an investigation into the reasons thereof. GEM uses the entrepreneurial conditions such as entrepreneurial finance, government policies, government programmes, entrepreneurial education, research and development transfer, commercial and legal infrastructure for entrepreneurship, internal market openness and cultural and social norms to measure entrepreneurial activity. Viewing the different entrepreneurial conditions, education is recognised as one of the largest inhibiters of entrepreneurship since 2001. In this study an investigation on education in South Africa was conducted. The goal of this study was to enhance selected entrepreneurial competencies of grade 11 learners in Business Studies. The literature study indicated that various entrepreneurship views and definitions exist. The focus of this study is on the individual characteristics of the entrepreneurs. The literature study also indicated that different terms exist to describe these individual characteristics of the entrepreneurs. For the purpose of this study the term competency was used. Thirdly the literature study also showed that various entrepreneurial competencies exist. A selection needed to be done and by using the curriculum of Business Studies, grades 10 – 12 only certain competencies were selected. The following entrepreneurial competencies are used in this study: problem solving, creativity, flexibility, risk-taking, goal orientation, planning, teamwork, communication, self-confidence and capacity to learn. In this study a multi-method research design was used. Both quantitative and qualitative research methods were used. An intervention took place with an experimental (23 learners) and control group (24 learners). Firstly the experimental group was exposed to the intervention with the control group attending normal classes. After the completion of the intervention on the experimental group the roles were changed. The intervention of each group consisted of 24 days (28 sessions of between 35 and 43 minutes). In the quantitative research three tests were used to determine the possible enhancement of the selected entrepreneurial competencies. Both the experimental and control group were exposed to the three tests. In the qualitative research observations and interviews were used to measure the possible enhancement of the entrepreneurial competencies. Learners from both the experimental and control group were used in the interviews. The results of the quantitative and qualitative research clearly show an enhancement of entrepreneurial competencies of the learners. Furthermore, the effectiveness of the proposed framework is clearly highlighted. The use of the proposed framework will assist teachers in linking the theory (textbook) and practice (operations of the business in the simulation). In addition, the teacher can expose the learners to entrepreneurial competencies and therefore develop and enhance it. Another advantage is that this teaching approach can be included in the normal Business Studies classes without any interruption of normal school activities. A limitation of the study is the period of the intervention. A recommendation is that the proposed strategy for the enhancement of entrepreneurial can be used through out the academic year for the enhancement of entrepreneurial competencies. This will ensure that the entrepreneurial competencies are focussed on continuously and learners are empowered in this regard. With this study the researcher attempted to address the challenges in education in South Africa through the enhancement of entrepreneurial competencies and thus to address the low TEA. / PhD (Entrepreneurship), North-West University, Potchefstroom Campus, 2014

The aim of this study is to analyse and interpret L.Z. Sikwane's play: Matshediso from the perspective of didascalies. The study comprises five chapters. The aim, scope and methods of research are outlined and motivated in chapter one. In chapter two, an overview of the research into didascalies is undertaken. Questions such as: "what are didascalies?" "how do didascalies in a play help produce meaning and shape?" etc. are dealt with. Later, the study shows how didascalies are linked to the other structural elements of drama such as theme; plot; characters and setting. In chapter three an analysis and interpretation of Matshediso from the perspective of the importance of didascalies is undertaken. This analysis focuses on the plot; didascalies and characters; didascalies and space; and didascalies, props, and set. Limitations characterizing performance are also dealt with. In chapter four, an integrated interpretation of Matshediso is provided. Thereafter a set of guidelines for performing the play is developed. This covers aspects such as: stage setting; the characters; dialogue; sound and costume. Chapter five sum up the main findings of the study and the value of the didascalies approach. By way of conclusion, I argue that Sikwane has not just written a play, but also pictured how it should be performed. This is confirmed by the didascalies included in this play and the value of the didascalies approach. / M.A., African Languages, Potchefstroom University for Christian Higher Education, 2002

Different researchers and governments globally have recognised the importance of entrepreneurship in economic growth and job creation. In addition, entrepreneurial activity is crucial, locally and globally. Furthermore, the Global Entrepreneurship Monitor (GEM) recognises the contribution of entrepreneurial activity to economic growth and measures it by means of the total early stage entrepreneurial activity index (TEA). Since the TEA in South Africa is very low, the need exist for an investigation into the reasons thereof. GEM uses the entrepreneurial conditions such as entrepreneurial finance, government policies, government programmes, entrepreneurial education, research and development transfer, commercial and legal infrastructure for entrepreneurship, internal market openness and cultural and social norms to measure entrepreneurial activity. Viewing the different entrepreneurial conditions, education is recognised as one of the largest inhibiters of entrepreneurship since 2001. In this study an investigation on education in South Africa was conducted. The goal of this study was to enhance selected entrepreneurial competencies of grade 11 learners in Business Studies. The literature study indicated that various entrepreneurship views and definitions exist. The focus of this study is on the individual characteristics of the entrepreneurs. The literature study also indicated that different terms exist to describe these individual characteristics of the entrepreneurs. For the purpose of this study the term competency was used. Thirdly the literature study also showed that various entrepreneurial competencies exist. A selection needed to be done and by using the curriculum of Business Studies, grades 10 – 12 only certain competencies were selected. The following entrepreneurial competencies are used in this study: problem solving, creativity, flexibility, risk-taking, goal orientation, planning, teamwork, communication, self-confidence and capacity to learn. In this study a multi-method research design was used. Both quantitative and qualitative research methods were used. An intervention took place with an experimental (23 learners) and control group (24 learners). Firstly the experimental group was exposed to the intervention with the control group attending normal classes. After the completion of the intervention on the experimental group the roles were changed. The intervention of each group consisted of 24 days (28 sessions of between 35 and 43 minutes). In the quantitative research three tests were used to determine the possible enhancement of the selected entrepreneurial competencies. Both the experimental and control group were exposed to the three tests. In the qualitative research observations and interviews were used to measure the possible enhancement of the entrepreneurial competencies. Learners from both the experimental and control group were used in the interviews. The results of the quantitative and qualitative research clearly show an enhancement of entrepreneurial competencies of the learners. Furthermore, the effectiveness of the proposed framework is clearly highlighted. The use of the proposed framework will assist teachers in linking the theory (textbook) and practice (operations of the business in the simulation). In addition, the teacher can expose the learners to entrepreneurial competencies and therefore develop and enhance it. Another advantage is that this teaching approach can be included in the normal Business Studies classes without any interruption of normal school activities. A limitation of the study is the period of the intervention. A recommendation is that the proposed strategy for the enhancement of entrepreneurial can be used through out the academic year for the enhancement of entrepreneurial competencies. This will ensure that the entrepreneurial competencies are focussed on continuously and learners are empowered in this regard. With this study the researcher attempted to address the challenges in education in South Africa through the enhancement of entrepreneurial competencies and thus to address the low TEA. / PhD (Entrepreneurship), North-West University, Potchefstroom Campus, 2014

The aim of this study is to analyse and interpret L.Z. Sikwane's play: Matshediso from the perspective of didascalies. The study comprises five chapters. The aim, scope and methods of research are outlined and motivated in chapter one. In chapter two, an overview of the research into didascalies is undertaken. Questions such as: "what are didascalies?" "how do didascalies in a play help produce meaning and shape?" etc. are dealt with. Later, the study shows how didascalies are linked to the other structural elements of drama such as theme; plot; characters and setting. In chapter three an analysis and interpretation of Matshediso from the perspective of the importance of didascalies is undertaken. This analysis focuses on the plot; didascalies and characters; didascalies and space; and didascalies, props, and set. Limitations characterizing performance are also dealt with. In chapter four, an integrated interpretation of Matshediso is provided. Thereafter a set of guidelines for performing the play is developed. This covers aspects such as: stage setting; the characters; dialogue; sound and costume. Chapter five sum up the main findings of the study and the value of the didascalies approach. By way of conclusion, I argue that Sikwane has not just written a play, but also pictured how it should be performed. This is confirmed by the didascalies included in this play and the value of the didascalies approach. / M.A., African Languages, Potchefstroom University for Christian Higher Education, 2002

A literature study was undertaken to investigate the experience of loss and grief in the different developmental stages, as well as to identify characteristics of loss and grief in the young child. Guidelines have been compiled on how to handle loss and grief in young children. The empirical study comprised of workshop presentations. Through these presentations it was also determined as to whether parents and children would benefit from such workshops, as well as if the information regarding loss and grief addressed the parents’ needs. The empirical study found that parents are ignorant about loss and grief in the young child. However, all the parents had questions about loss and grief. After the workshops parents indicated that they became aware of positive changes in their own behaviour towards their children, and also in that of their children. One of the biggest problems in handling loss and grief in the young child seemed to be open and honest communication. / Educational Studies / M.Ed. (Guidance and Counseling)

En formation professionnelle agricole au Québec, dans un contexte où les formations en alternance sont privilégiées pour favoriser la réussite, la question de l'arrimage entre les pratiques éducatives des enseignants et celles des formateurs en entreprises est posée. Dans une perspective compréhensive de la recherche s'appuyant sur la stratégie de l'étude de cas, l'arrimage a été abordé selon trois points de vue: (1) à travers une séquence école-stage-école; (2) à travers les systèmes de pratiques professionnelles propres à chaque intervenant et (3) à travers le déroulement de pratiques spécifiques que sont les pratiques d'enseignement à l'école et les pratiques de formation en entreprise. L'analyse de contenu des entrevues et des observations en classes et en entreprises fait notamment ressortir l'hétérogénéité des pratiques, l'importance de la structure scolaire en regard de l'alternance et de l'arrimage qu'elle permet, ainsi que certaines faiblesses concernant la didactique de l'alternance chez les enseignants et le guidage de l'activité chez les formateurs en entreprises. Ainsi, bien que, majoritairement, l'arrimage ne résulte pas d'une démarche volontaire de la part des formateurs en entreprise, il passe notamment par les objets, les lieux et les moyens de formation, malgré un manque de temps évident, et repose essentiellement sur la planification rigoureuse des enseignants. Pour les enseignants, l'arrimage s'effectue à travers des pratiques formelles telles les pratiques d'enseignement et les pratiques de supervision, et à travers des pratiques informelles telles les pratiques de corridor. Dans les pratiques d'enseignement, l'arrimage consiste en l'apport continu de situations vécues par les élèves ou par les enseignants, et par des apports théoriques liés à la réalité en entreprise. Pour les formateurs en entreprise, l'arrimage s'effectue par la mise en action de l'élève dans un travail lié à la formation à l'école, et par un minimum d'informations liées à la formation à l'école.

In the post-industrial society, career management has become vitally important for assisting workers to be employable. This study aimed to investigate the relationship between career anchors and employability. The effort of researching these concepts is geared towards adding to the knowledge base in the field of Industrial and Organisational Psychology, so that the current organisation from which the sample was chosen and other organisations in South Africa can adopt a strong career management culture. A quantitative survey using primary data was conducted on a convenience sample (N=108) of full-time employees in a South African financial company. The Career Anchors Inventory (COI) and the Employability Attribute Scale (EAS) were used to gather data. The study found a statistically significant positive relationship between career anchors and employability. In addition, there were significant correlations between the sub-constructs of career anchors and employability, while significant differences in career anchor preferences and employability perceptions between males and females emerged. The only differences in career anchor preferences were detected between racial and age groups. The results indicate a mutual and positive relationship between career anchors and employability, which can be useful in career guidance in the 21st century. / Industrial & Organisational Psychology / M. A. (Industrial and Organisational Psychology)

BACKGROUND:The aim of this study was to evaluate clinico-pathologic specific predictors of recurrence for stage II/III disease. Improving recurrence prediction for resected stage II/III colon cancer patients could alter surveillance strategies, providing opportunities for more informed use of chemotherapy for high risk individuals.METHODS:871 stage II and 265 stage III patients with colon cancers were included. Features studied included surgery date, age, gender, chemotherapy, tumor location, number of positive lymph nodes, tumor differentiation, and lymphovascular and perineural invasion. Time to recurrence was evaluated, using Cox's proportional hazards models. The predictive ability of the multivariable models was evaluated using the concordance (c) index.RESULTS:For stage II cancer patients, estimated recurrence-free survival rates at one, three, five, and seven years following surgery were 98%, 92%, 90%, and 89%. Only T stage was significantly associated with recurrence. Estimated recurrence-free survival rates for stage III patients at one, three, five, and seven years following surgery were 94%, 78%, 70%, and 66%. Higher recurrence rates were seen in patients who didn't receive chemotherapy (p=0.023), with a higher number of positive nodes (p<0.001). The c-index for the stage II model was 0.55 and 0.68 for stage III.CONCLUSIONS:Current clinic-pathologic information is inadequate for prediction of colon cancer recurrence after resection for stage II and IIII patients. Identification and clinical use of molecular markers to identify the earlier stage II and III colon cancer patients at elevated risk of recurrence are needed to improve prognostication of early stage colon cancers.