Magister Commercii - MCom / In Rwanda, there is a serious concern that the human resource capacities to formulate and implement policies and programmes and deliver quality services to meet the Government's development priorities are not only limited but are eroding as well, despite efforts to the contrary. The purpose of this study is to examine the challenges of Human Resource capacity building and retention in the Rwandan Public Sector. Specific objectives are (i) to identify the civil servants' perceived reasons that make them quit the public sector after acquiring the desired skills by their working institutions; (ii) to identify the civil servants' perceptions on the measures to improve capacity retention in Rwandan public sector; (iii) to review the capacity building and retention challenges facing the Rwandan public sector; (iv) to contextualize problems of capacity building and capacity retention within the broader literature; and (v) to make recommendations regarding the specific strategies the Rwandan Public Sector should adopt to retain civil servants. The study was carried out in Western Cape Province, at the Universities of University of the Western Cape (UWC), Cape Peninsula University of Technology (CPUT), University of Cape Town (UCT) and University of Stellenbosch (US). The eligible study participants were postgraduate Rwandan students pursuing masters and doctoral studies in various fields. A descriptive quantitative study design was used to collect data on the participants' perceived reasons as to why, after training, civil servants are likely to quit the public sector, together with the measures participants feel the Rwanda Public sector could put in place to retain the employees after training, as well as the human resource challenges facing Rwandan public sector. All 40 Rwandan postgraduate students pursuing masters and doctoral studies at the selected universities (based on Rwandan Embassy Records for 2010) were the sample for this study, and there was a 100% response rate. A structured self-administered, close-ended and pre-coded questionnaire was used to collect data. Data was analysed using the SPSS software programeme, and descriptive statistics were used to describe various variables to answer the research questions. With regard to research ethics permission was granted by the Higher Degrees Committee of UWC and ethical clearance was obtained from the Research Grants and Study Leave Committee at UWC. Permission to conduct the study among Rwandanmasters and doctoral students on capacity building programmes supported by the Government of Rwanda was granted by the Rwandan Embassy. The purpose of the study was explained to the participants using the participants' information sheet. Signed informed consent both written and verbal was obtained from each individual participant. Participation was voluntary, anonymity of participants was assured, participants information was kept confidential and voluntary withdraw from the study at any time was guaranteed to participants. The findings demonstrate that 45% of the respondents do not intend to continue working in the Public Sector after training due to both financial considerations and workplace working conditions.The findings also indicate that 55% of the respondents intend to work in the public sector after training. The research recommends, amongst other things, that a larger survey be conducted among Rwandan students on study abroad programmes to ascertain if the reasons for quitting and perceived measures to remain in the public sector after training hold for all the civil servants on capacity building programmes.

Le régime de l’auto-entrepreneur connaît depuis sa création un succès considérable en termes d’adhésions. Mais son principe phare de simplification en fait sa propre faiblesse. D’un régime social et fiscal incitatif constituant une alternative au chômage, l’auto-entrepreneuriat suscite aussi la tentation de l’abus. A l’examen attentif de ses motivations et de la réalisation économique de son projet-entrepreneurial, la réalité de l’auto-entrepreneur émerge. A l’image d’entrepreneur autonome libre de ses choix se superposent les nécessités d’un travailleur, employeur de lui-même et de nul autre, employé de lui-même à défaut de l’être par un autre. Après avoir analysé les séductions et les travers du régime, l’étude propose de sécuriser l’auto-entrepreneuriat en explorant les potentialités du droit du travail à l’accueillir. L’observation des dispositifs similaires des voisins européens dresse une perspective plausible d’émergence d’un droit de l’auto-entrepreneuriat dès lors qu’il n’attente pas à celui des autres acteurs économiques, en premier lieu celui des salariés. / Self-employment scheme have been considerably successful since their introduction. However, its flagship principle of simplification is also its main weakness. While self-employment schemes provide social and fiscal alternatives to unemployment, they can also be easily abused. The reality of self-employment emerges from an assessment of a project’s motivating factors and of its economic implementation. The image of an autonomous entrepreneur with freedom of choices becomes superimposed with the needs of a worker, employing himself and nobody else, employed by himself and not by someone else. After having analyzed the appeals and faults of self-employment scheme, this study proposes more secure self-employment principles by exploring the potential of its inclusion in labour law. An observation of similar mechanisms in neighboring European countries suggests a plausible perspective for the emergence of stronger self-employment right, as long as this does not violate the rights of other economic actors, primarily that of salaried employees.The image of an autonomous entrepreneur with freedom of choices becomes superimposed with the needs of a worker, employing himself and nobody else, employed by himself and not by someone else.

This thesis has proposed two types of real time System Integrity Protection Schemes(SIPS) using Emergency Single Machine Equivalent (E-SIME) and Model PredictiveControl (MPC) approaches respectively. They are aiming to resolve the transientstability problems in power systems. Synchronous measurements, fast communicationnetwork and FACTS are deployed in the two SIPSs. The Thyristor Controlled SeriesCompensation (TCSC) is applied as the control action in both SIPSs.In the E-SIME based SIPS, the SIME approach is used to evaluate the transient stabilityof the system and then a decision is made about the control actions needed to stabilizethe system. During emergency conditions, a fast response time is very important andthis requires a security guideline to be used in the decision making process. Theguideline is developed by analyzing offline multiple fault scenarios using an automaticlearning approach. This ensures appropriate control actions can be performed withoutcompromising the response time required on a real system.The MPC based SIPS optimizes the control action at every discrete time instant byselecting the control action that leads to the minimized cost function value. Automaticlearning (AL) is utilized to predict power system dynamics by assuming each controlaction has been taken. Furthermore, a feature selection technique, that chooses themost relevant variables, is used to improve the performance of the AL prediction. Themodel predictive control (MPC) technique is performed every discrete time interval, sothe optimal control action is always selected.Two types of SIPS are tested and verified in the benchmark systems. Simulation resultsshow they can effectively protect the system from loss of synchronism in the aftermathof a large disturbance. This thesis also compares the two SIPSs and concludes thebenefits and shortcomings of each approach.

The content of this thesis is the design of a condensing steam turbine with an output of 80 MWe to a waste incinerator with impulse blading. In this work are elaborated proposals and calculations of balancing schemes, which are used in the next part of the work as a foundation for calculation of the blades part of the turbine. The blades part is designed for two operations - for full condensing operation and for full demand operation. The turbine should contain one process offtake and three unregulated offtakes. Besides that, the thesis solves basic strength control. The thesis is finished with a technical drawing of the longitudinal cut of the turbine.

The classical SIR and SIS epidemiological models are extended by considering the number of adequate contacts per infective in unit time as a function of the total population in such a way that this number grows less rapidly as the total population increases. A diffusion term is added to the SIS model and this leads to a reaction–diffusion equation, which governs the spatial spread of the disease. With the parameter R0 representing the basic reproduction number, it is shown that R0 = 1 is a forward bifurcation for the SIR and SIS models, with the disease–free equilibrium being globally asymptotic stable when R0 is less than 1. In the case when R0 is greater than 1, for both models, the endemic equilibrium is locally asymptotically stable and traveling wave solutions are found for the SIS diffusion model. Nonstandard finite difference (NSFD) schemes that replicate the dynamics of the continuous SIR and SIS models are presented. In particular, for the SIS model, a nonstandard version of the Runge-Kutta method having high order of convergence is investigated. Numerical experiments that support the theory are provided. On the other hand the SIS model is extended to a Volterra integral equation, for which the existence of multiple endemic equilibria is proved. This fact is confirmed by numerical simulations. / Dissertation (MSc)--University of Pretoria, 2012. / Mathematics and Applied Mathematics / unrestricted

Magister Commercii - MCom / This minithesis aims to determine whether South Africa's microfinance institutions are operating efficiently and whether efficiency can be enhanced. Using the United Nations model and framework for efficiency, it examines the key principles of operational efficiency in the South African microfinance context. The paper begins with an overview of the literature relating to the principles of efficiency as underscored in the United Nations model.

We introduce an adaptive pacing scheme to overcome the drawbacks of TCP in wireless mesh networks with Internet connectivity. The pacing scheme is implemented at the wireless TCP sender as well as at the mesh gateway, and reacts according to the direction of TCP flows running across the wireless network and the Internet. TCP packets are transmitted rate-based within the TCP congestion window according to the current out-of-interference delay and the coefficient of variation of recently measured round-trip times. Opposed to the majority of previous work which builds on simulations, we implement a Linux prototype of our approach and evaluate its feasibility in a real 20-node mesh testbed. In an experimental performance study, we compare the goodput and fairness of our approach against the widely deployed TCP NewReno. Experiments show that our approach, which we denote as Mesh Adaptive Pacing (MAP), can achieve up to 150% more goodput than TCP NewReno and significantly improves fairness between competing flows. MAP is incrementally deployable since it is TCP-compatible, does not require cross-layer information from intermediate nodes along the path, and requires no modifications in the wired domain.

The fundamental goal of this study was to measure the levels and causes of stress of employees in an organisation undergoing immense change, including a transaction whereby the full administrative and managed healthcare operations are sold to a prominent insurance company (acquisition). This change represents an acquisition of the intellectual capital and systems of a mutual open medical scheme by a major insurance company with a well established brand equity and profile in the South African insurance market. The importance of the study is imperative as it forms an integral part of the management of change programmes. The goal is to execute a paradigm shift in leaving behind old comfort zones and moving towards a competitive workforce in a highly competitive environment with an outcomes based approach to business. The identification of the most important levels and causes of work stress will enable the organization to address factual situations and to build these strategies into its change programmes, whilst not relying on generic, non-focused initiatives with marginal success outcomes. Some organisations are more stressful than others and in order to manage stress and embark on effective strategies to cope with stress, the unique disposition of the organisation and its employees needed to be identified. The data was collected electronically via the organisation’s Intranet by means of the Experience of Work and Life Circumstances Questionnaire (WLQ), compiled by Van Zyl and Van der Walt of the Human Sciences Research Council in 1991. The questionnaire was developed to determine the levels and causes of stress of employees. The WLQ endeavours to establish whether employees experience normal, high or very high levels of stress and also identify those factors which cause these levels of stress. The questionnaire consists of three different parts namely, a demographic questionnaire, experience of work which determine the levels of stress and finally, circumstances and expectations which analyses the causes of stress. It was clear from the study that organisational change, such as is experienced by the employees of this organisation, does lead to increased and higher stress levels. It was further demonstrated from the results that uncertainty and lack of control over their own destiny and immediate circumstances, contributed to an increase in the levels of stress. Copyright 2009, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: V an Zyl, P 2009, The measurements of levels and causes of work stress of employees in a competitive open medical scheme in the privater sector, MCom dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-03152012-170001 / > C12/4/69/gm / Dissertation (MCom)--University of Pretoria, 2009. / Human Resource Management / unrestricted

The rapid development of Machine Learning algorithms and a growing range of its applications, as well as an increasing number of Edge Computing devices, created a need for a new paradigm that would benefit from both fields. Federated Learning, which emerged as an answer to this need, is a technique that also solves privacy-related issues arising when large amounts of information are collected on many individual devices and being used for a Machine Learning model by sending only the local updates and keeping the data. At the same time, Federated Learning heavily relies on the computational and communicational capabilities of the devices that calculate the updates and send them to the main server to be integrated into a global model using one or the other Aggregation Scheme, which is one of the most important aspects of the Federated Learning. Carefully choosing how to aggregate local updates can diminish the impacts present from a huge variety of devices. Therefore, this thesis work presents a thorough investigation of the Aggregation Schemes and analyzes their behaviors in heterogeneous Federated Learning scenarios. It provides an extensive description of the main features of schemes studied, defines the evaluation criteria, presents the resource costs associated with computational and communicational resources of the devices, and shows a fair assessment.

As traditional communication technology we use in our day-to-day life reaches its limitations, the international community searches for new methods to communicate information. One such novel approach is the so-called molecular communication system. During the last few decades, molecular communication systems become more and more popular. The main difference between traditional communication and molecular communication systems is that in the latter, information transfer occurs through chemical means, most often between microorganisms. This process already happens all around us naturally, for example, in the human body. Even though the molecular communication topic is attractive to researchers, and a lot of theoretical results are available - one cannot claim the same about the practical use of molecular communication. As for experimental results, a few studies have been done on the macroscale, but investigations at the micro- and nanoscale ranges are still lacking because they are a challenging task. In this work, a self-contained introduction of the underlying theory of molecular communication is provided, which includes knowledge from different areas such as biology, chemistry, communication theory, and applied mathematics. Two numerical methods are implemented for three well-studied partial differential equations of the MC field where advection, diffusion, and the reaction are taken into account. Numerical results for test cases in one and three dimensions are presented and discussed in detail. Conclusions and essential analytical and numerical future directions are then drawn.