The heterogeneous deployment of small cells (e.g., femtocells) in the coverage area of the traditional macrocells is a cost-efficient solution to provide network capacity, indoor coverage and green communications towards sustainable environments in the future fifth generation (5G) wireless networks. However, the unplanned and ultra-dense deployment of femtocells with their uncoordinated operations will result in technical challenges such as severe interference, a significant increase in total energy consumption, unfairness in radio resource sharing and inadequate quality of service provisioning. Therefore, there is a need to develop efficient radio resource management algorithms that will address the above-mentioned technical challenges. The aim of this thesis is to develop and evaluate new efficient radio resource management algorithms that will be implemented in cognitive radio enabled femtocells to guarantee the economical sustainability of broadband wireless communications and users' quality of service in terms of throughput and fairness. Cognitive Radio (CR) technology with the Dynamic Spectrum Access (DSA) and stochastic process are the key technologies utilized in this research to increase the spectrum efficiency and energy efficiency at limited interference. This thesis essentially investigates three research issues relating to the efficient radio resource management: Firstly, a self-organizing radio resource management algorithm for radio resource allocation and interference management is proposed. The algorithm considers the effect of imperfect spectrum sensing in detecting the available transmission opportunities to maximize the throughput of femtocell users while keeping interference below pre-determined thresholds and ensuring fairness in radio resource sharing among users. Secondly, the effect of maximizing the energy efficiency and the spectrum efficiency individually on radio resource management is investigated. Then, an energy-efficient radio resource management algorithm and a spectrum-efficient radio resource management algorithm are proposed for green communication, to improve the probabilities of spectrum access and further increase the network capacity for sustainable environments. Also, a joint maximization of the energy efficiency and spectrum efficiency of the overall networks is considered since joint optimization of energy efficiency and spectrum efficiency is one of the goals of 5G wireless networks. Unfortunately, maximizing the energy efficiency results in low performance of the spectrum efficiency and vice versa. Therefore, there is an investigation on how to balance the trade-off that arises when maximizing both the energy efficiency and the spectrum efficiency simultaneously. Hence, a joint energy efficiency and spectrum efficiency trade-off algorithm is proposed for radio resource allocation in ultra-dense heterogeneous networks based on orthogonal frequency division multiple access. Lastly, a joint radio resource allocation with adaptive modulation and coding scheme is proposed to minimize the total transmit power across femtocells by considering the location and the service requirements of each user in the network. The performance of the proposed algorithms is evaluated by simulation and numerical analysis to demonstrate the impact of ultra-dense deployment of femtocells on the macrocell networks. The results show that the proposed algorithms offer improved performance in terms of throughput, fairness, power control, spectrum efficiency and energy efficiency. Also, the proposed algorithms display excellent performance in dynamic wireless environments.

Includes abstract. / Includes bibliographical references. / Growing consumer awareness of animal welfare has co-evolved with increases in intensive farming, particularly of battery chickens. This rise in consumer awareness recently saw bans on battery farming in parts of Europe. This thesis addresses the difficulties that would follow any similar attempt to curtail battery farming in South Africa. It examines the literature on animal rights and the welfare issues generated by intensive animal farming, particularly of battery chickens. Thereafter it summarises the findings of surveys into local consumer preferences and retail strategies regarding chicken products.

Includes bibliographical references (leaves 71-77). / The South African Government's anti-poverty strategy has been largely dominated by unconditional cash transfers. A growing body of literature examines the impacts of these transfers on a range of socio-economic outcomes; however there is little discussion of why such impacts are important. Without an explicit conceptual framework within which to examine these effects, evaluating their likely long term poverty impacts remains problematic. The focus of this research is to distil the current thinking on poverty and social protection to establish an appropriate theoretical framework within which to appraise anti-poverty measures. 'An Assets-Augmented' Capabilities Framework is proposed with a focus on asset-building as the primary means of poverty reduction. Focusing on the Child Support Grant (CSG), empirical analysis is then applied to examine whether the underlying causes of poverty are being addressed. Using the National Income Dynamics Study (NIDS) Wave 1 Dataset, the effects of the CSG on households' expenditure patterns are examined to assess the extent to which CSG-recipients invest in asset-building. A propensity score matching method is employed to construct an appropriate counterfactual. Households receiving the CSG are not found to exhibit significantly different expenditure patterns compared to a control group and cannot therefore be argued to invest differently in assets. This key finding provides evidence that the CSG primarily addresses the symptoms of poverty and cannot be expected to generate sustainable poverty reduction. A linking approach is thus proposed to combine the cash transfer element of the grant with more explicitly promotional measures in order to seek greater asset effects. A key recommendation is to ensure that the CSG acts as a gateway to other complementary services and benefits in order to increase the value of the grant with relatively little additional effort or cost.

Submitted in fulfilment of the academic requirements for the degree of Master of Science in School of Molecular and Cell biology University of the Witwatersrand Johannesburg, South Africa / Esterases are hydrolytic enzymes that have many industrial applications. They are used in food, pharmaceutical, pulp and paper, cosmetics, biofuels and many other industries. This gives research of these enzymes major importance. Esterase genes received from CSIR Biosciences were cloned in E. coli DH5α cells. The plasmids carrying these genes were pET20b(+) for genes named Est1, Est2, Est3, Est4, Est5, Est6, Est7, Est8, Est9, Est10, Est12, Est13, Est14 and pET28a(+) for Est11. These plasmids were extracted from the cloning host and transformed into the expression host which was E. coli BL21. The cells were then induced for expression and the presence of the protein bands representing the products of expression were confirmed by running the crude enzyme extract on SDS-Page. The enzyme extracts were tested for activity using pNp-acetate. All 14 esterases were active and they were characterised in terms of pH optima, temperature optima and kinetics. The enzymes showed a pH range of 6.0 to 9.0 and temperature range of 30°C to 50°C. The enzymes were investigated for substrate specificity and they showed a greater preference for short acyl chain substrates over long acyl chain substrates. Further testing was done for activity of the enzymes using α-naphthylbutyrate and naphthol AS-D chloroacetate alongside lipases. A total of 87 enzymes were tested using these colorimetric assays and 36 of the enzymes were found to be active including all 14 esterases. These 36 enzymes were tested for use in enzymatic resolution of three different chemical compounds available as racemic mixtures. No success was observed for two of the compounds but one of them showed some enantioselectivity. This research will be furthered on at large scale to allow continued synthesis of potential HIV-1 protease inhibitors.

Abstract Not Provided / Thesis / Master of Arts (MA)

yes / Guest Editorial of Special Issue (featuring eight original papers, comprising 133 pages in total). Whilst satellite systems continue to be at the forefront of broadcast communication service provision, they have an increasingly important role to play in the provision of global Internet services. There has been a strong trend towards convergence of communication services in recent times, with the Internet providing the ideal platform on which to base such convergence. Even traditional circuit-switched applications (such as voice and video streaming) have been shown to work effectively over the Internet. Although the Internet is prevalent in the developed world, satellites are vital to extending this into more remote and sparsely populated regions of the world. It is therefore important that satellite technology is advanced to provide seamless interoperability with the Internet and adequate Quality of Service (QoS) support. The purpose of this special issue is to present research devoted to furthering satellite technology and networking to support the provision of both current and future applications.

Abstract Not Provided / Thesis / Master of Science (MSc)

A formula for the average fade time of the intensity of a spherical optical wave travelling through atmospheric turbulence is developed. The model employed involves isotropic, homogeneous statistics using a lognormal distribution for the channel. The analysis is based on the fact that the logarithm of the irradiance is normally distributed and uses the work of S. O. Rice who developed such an expression for a zero mean, Gaussian process. The analysis employs the covariance function and the Taylor frozen turbulence hypothesis which results in an expression for the autocorrelation function.

Yes / The effective deployment of FMEAs within complex automotive applications faces a number of challenges, including the complexity of the system being analysed, the need to develop a series of coherently linked FMEAs at different levels within the systems hierarchy and across intrinsically interlinked engineering disciplines, and the need for coherent linkage between critical design characteristics cascaded through the systems levels with their counterparts in manufacturing. The approach presented in this paper to address these challenges is based on a structured Failure Mode Avoidance (FMA) framework which promotes the development of FMEAs within an integrated Systems Engineering approach. The effectiveness of the framework is illustrated through a case study, centred on the development of a diesel exhaust aftertreatment system. This case study demonstrates that the structured FMA framework for function analysis supports an effective decomposition of complex interdisciplinary systems facilitating the DFMEA deployment through a series of containable, structured DFMEAs developed at successive system levels, with clear vertical integration of functional requirements and critical parameters cascade. The paper also discusses the way in which the approach supports deployment across engineering disciplines and domains, ensuring the integrity of information flow between the design and manufacturing activities.

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