A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. May 27, 2016. / Heat transfer in a wall with temperature dependent thermal conductivity and internal heat generation is considered. We rst focus on the steady state models followed by the transient heat transfer models. It turns out that the models considered are non-linear. We deliberately omit the group-classi cation of the arbitrary functions appearing in the models, but rather select forms of physical importance. In one case, thermal conductivity and internal heat generation are both given by the exponential function and in the other case they are given by the power law. We employ the classical Lie point symmetry analysis to determine the exact solutions, while also determining the optimal system for each case. The exact solutions for the transient models are di cult to construct. However, we rst use the obtained exact solution for the steady state case as a benchmark for the 1D Di erential Transform Method (DTM). Since con dence in DTM is established, we construct steady state approximate series solutions. We apply the 2D DTM to the transient problem. Lastly we determine the conservation laws using the direct method and the associated Lie point symmetries for the transient problem / MT2016

Background Gert Sibande District has the highest HIV prevalence among women attending public antenatal health clinics. Multiple sexual partnerships (MSP) enhance heterosexual HIV transmission, which is the main form of transmission in South Africa. There is need, therefore, to identify important factors associated with MSP for the development of strategic intervention policies and programmes. Objectives To determine the prevalence and associated factors of multiple sexual partnerships (MSP) in men and women in Gert Sibande District (GSD) in 2010. Methods This is a secondary data analysis of data collected through a cross-sectional multi-stage study using cluster probability sampling technique in GSD in 2010. The study collected data on 750 adult men and women aged 16 to 55 years through an interviewer-administered standardised questionnaire. Simple descriptive statistics and chi square analysis were used to determine the prevalence and patterns of the MSP in the study population. Multiple logistic regression models were built to determine factors that were independently associated with MSP. Results The analysis included 592 sexually active respondents: 200 men and 392 women. A fifth of the respondents had had their first sexual encounter before the age of 16 years. Condom use was higher among men than women. Condom use was lowest with most recent partners (56.6%) than in second (74.6%) and third sexual partners (78.6%). Alcohol use was high, with more men (72.0%) than women (33.2%) having ever consumed alcohol (p<0.001) and among these alcohol users, more men (44.5%) than women (8.7%) were involved in risky drinking. The overall reported MSP prevalence was 22.0%, 95% CI: 19 - 25%. Men (44.0%, 95% CI: 37 - 51%) reported significantly higher levels of MSP than women (10.7%, 95% CI: 8 - 12%). Levels of MSP decreased with age and were highest among young adults, men (20 to 24 years) and women (15 to 19 years), those who were never married, and among men in the intermediate socio-economic group. There were significant associations between MSP and underlying socio-demographic factors (age, socio-economic status and marital status), and with intermediate sexual behavioural factors (age at first sex, condom use at last sex), sex under the influence of alcohol and transactional sex in the past 12 months). Among men, young age (AOR 3.0, 95% CI: 1.0 - 9.3) socio-economic status (AOR 3.1, 95% CI: 1.7 - 5.6) predicted having MSP. The strongest positive correlation of MSP among men occurred with the sexual behavioural factors, particularly age at first sex (AOR 9.7, 95% CI: 2.3 - 41.4) and having sex under the influence of alcohol (AOR 4.5, 95% CI: 1.9 - 9.7). There was a 4.5 times likelihood of MSP with transactional sex in the past 12 months. Among women, being never married (AOR 10.9, 95% CI: 1.3 – 90.3), condom use at last sex (AOR 2.4, 95% CI: 1.1 – 5.6), transactional sex in the past 12 months (AOR 12.0, 95% CI: 3.9 – 37.1) and having sex under the influence of alcohol (AOR 9.3, 95% CI: 4.4 – 19.6) were significantly associated with increased odds of MSP. Conclusion The findings of this study showed a high prevalence of MSP compared to the reported prevalence of MSP in the South African national and sub-national surveys (SABSSM, NCS and DHS). The prevalence was ever higher across some sub-groups of the population. The findings highlight the need for interventions that will address socio-economic factors influence MSP in GSD, especially among young adults and unmarried adults of GSD. Among this largely black population, the occurrence of several sexual risk factors, including early age at first sex, transactional sex, and high alcohol use, indicate the need for group-specific interventions. This study also provides a basis for future research to allow for the comparison of changes in MSP levels among adults of GSD and for prevention interventions targeting partner reduction.

Digital treinsmission of information is finding an ever-increasing number of applications in the leind-mobile radio service. There is a possibility that in the long term, due to the increasing demand for mobile radio channels, their bandwidths will be reduced to 5kHz. A digital minimum shift keying (MSK) modulation scheme is proposed in this work for narrow band digital mobile radio transmission. The design and implementation of an MSK modulator and coherent and noncoherent demodulators are given. Their structure is highly flexible and can accommodate a wide range of medium digital transmission rates. The demodulators were tested for the transmission of 2.4kbit/sec in simulated typical land-mobile radio transmission conditions. The results of these tests favoured the use of the noncoherent demodulator for this type of application. Achieving spectrum efficiency in this proposed scheme relies on postmodulation filtering of the MSK signal. A polar loop VHF transmitter was tested for high efficiency linear power amplification of the MSK signal. It proved its validity for this type of application. A digital clock recovery circuit suitable for use in mobile radio conditions has also been built and tested. The principles of the circuit operation and its implementation are discussed.

by Poon Yim-chu Daisy. / Bibliography: leaves 128-148 / Thesis (M.Phil.) -- Chinese University of Hong Kong, 1983

by Chun-tat See. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1991. / Includes bibliographical references. / ACKNOWLEDGEMENTS --- p.i / ABSTRACT --- p.ii / NOTATIONS --- p.iv / TABLE OF CONTENTS --- p.vi / Chapter 1. --- INTRODUCTION --- p.1-1 / Chapter 1.1 --- Introduction --- p.1-1 / Chapter 1.2 --- A Basic Transform Coding System --- p.1-2 / Chapter 1.3 --- Thesis Organization --- p.1-5 / Chapter 2. --- DYADIC MATRICES AND THEIR APPLICATION --- p.2-1 / Chapter 2.1 --- Introduction --- p.2-1 / Chapter 2.2 --- Theory of Dyadic Matrix --- p.2-2 / Chapter 2.2.1 --- Basic Definitions --- p.2-3 / Chapter 2.2.2 --- Maximum Size of Dyadic Matrix --- p.2-8 / Chapter 2.3 --- Application of Dyadic Matrix in Generating Orthogonal Transforms --- p.2-13 / Chapter 2.3.1 --- Transform Performance Criteria --- p.2-14 / Chapter 2.3.2 --- "[T1] = [P]Diag([DM2(4)],[A(4)])[Q]" --- p.2-19 / Chapter 2.3.3 --- "[T2] = [P]Diag([DM2(4)],[DM2(4)])[Q]" --- p.2-21 / Chapter 2.4 --- Discussion and Conclusion --- p.2-26 / Chapter 3. --- LOW SEQUENCY COEFFICIENT TRUNCATION (LSCT) CODING SCHEME --- p.3-1 / Chapter 3.1 --- Introduction --- p.3-1 / Chapter 3.2 --- DC Coefficient Estimation Schemes --- p.3-2 / Chapter 3.2.1 --- Element Estimation --- p.3-2 / Chapter 3.2.2 --- Row Estimation --- p.3-4 / Chapter 3.2.3 --- Plane Estimation --- p.3-7 / Chapter 3.3 --- LSCT Coding Scheme 1 and Results --- p.3-11 / Chapter 3.4 --- LSCT Coding Scheme 2 and Results --- p.3-17 / Chapter 3.5 --- Discussions and Conclusions --- p.3-21 / Chapter 4. --- VARIABLE BLOCK SIZE (VBS) CODING SCHEME --- p.4-1 / Chapter 4.1 --- Introduction --- p.4-1 / Chapter 4.2 --- Chen's VBS Coding Scheme and Its Limitation --- p.4-3 / Chapter 4.3 --- VBS Coding Scheme With Block Size Determined Using Edge Discriminator --- p.4-6 / Chapter 4.4 --- Simulation Results --- p.4-8 / Chapter 4.5 --- Discussions and Conclusions --- p.4-12 / Chapter 5. --- ENHANCEMENT OF JPEG INTERNATIONAL STANDARD --- p.5-1 / Chapter 5.1 --- Introduction --- p.5-1 / Chapter 5.2 --- The Basic JPEG International Standard --- p.5-2 / Chapter 5.2.1 --- Level Shift and Discrete Cosine Transform --- p.5-4 / Chapter 5.2.2 --- Uniform Quantization --- p.5-5 / Chapter 5.2.3 --- Coefficient Coding --- p.5-7 / Chapter 5.3 --- Efficient DC Coefficients Encoding --- p.5-8 / Chapter 5.3.1 --- The Minimum Edge Difference (MED) Predictor --- p.5-8 / Chapter 5.3.2 --- Simulation Results --- p.5-9 / Chapter 5.3.3 --- Pixel Domain Predictors --- p.5-13 / Chapter 5.3.4 --- Discussion and Conclusion --- p.5-15 / Chapter 5.4 --- JPEG Scheme Using Variable Block Size Technique --- p.5-15 / Chapter 5.4.1 --- Scheme 1 --- p.5-16 / Chapter 5.4.2 --- Scheme 2 --- p.5-25 / Chapter 5.4.3 --- Scheme 3 --- p.5-27 / Chapter 5.4.4 --- Scheme 4 --- p.5-29 / Chapter 5.4.5 --- Scheme 5 --- p.5-32 / Chapter 5.4.6 --- Discussions and Conclusions --- p.5-32 / Chapter 5.5 --- Conclusions --- p.5-33 / Chapter 6. --- CONCLUSIONS --- p.6-1 / Chapter 6.1 --- Summary of Research Work --- p.6-1 / Chapter 6.2 --- Contributions of Work --- p.6-2 / Chapter 6.3 --- Suggestions for Further Research --- p.6-3 / Chapter 7. --- REFERENCES --- p.7-1 / RESULTS

by Francis Fuk-sing Wu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1991. / Bibliography: leaves [90]-[94] / LIST OF FIGURES --- p.vii / LIST OF TABLES --- p.ix / NOTATIONS --- p.x / Chapter 1 --- INTRODUCTION / Chapter 1.1 --- Introduction --- p.1-1 / Chapter 1.2 --- Properties of Orthonormal Transforms --- p.1-4 / Chapter 1.3 --- Some Considerations of a Transform System --- p.1-5 / Chapter 1.4 --- Motivation of Work --- p.1-7 / Chapter 1.5 --- Organization of the Thesis --- p.1-9 / Chapter 2 --- COVARIANCE ESTIMATION SCHEMES AND PERFORMANCE COMPARISON OF THE KLT'S / Chapter 2.1 --- Introduction --- p.2-1 / Chapter 2.2 --- Statistics of an Image --- p.2-1 / Chapter 2.3 --- Mathematical Covariance Functions --- p.2-3 / Chapter 2.3.1 --- One-Dimensional : First-Order Markov Model --- p.2-3 / Chapter 2.3.2 --- Two-Dimensional : Separable and Non-Separable Isotropic Models --- p.2-3 / Chapter 2.4 --- Goviance Estimation Schemes --- p.2-5 / Chapter 2.4.1 --- Scheme 1 --- p.2-5 / Chapter 2.4.2 --- Scheme 2 --- p.2-7 / Chapter 2.4.3 --- Scheme 3 --- p.2-8 / Chapter 2.5 --- KLT's of Different Random Processes --- p.2-11 / Chapter 2.6 --- Transform Comparison Based on Real Images --- p.2-14 / Chapter 2.7 --- Concluding Remarks --- p.2-18 / Chapter 3 --- DC TRANSFORMED ENERGY PACKING ABILITY OF KLT AND DCT / Chapter 3.1 --- Introduction --- p.3-1 / Chapter 3.2 --- Analysis of DC Transformed Energy Using Mathematical Covariance Models --- p.3-1 / Chapter 3.2.1 --- First-Order Markov Process --- p.3-1 / Chapter 3.2.2 --- Separable Model --- p.3 -3 / Chapter 3.2.3 --- Non-Separable Isotropic Model --- p.3-4 / Chapter 3.2.4 --- Results --- p.3-5 / Chapter 3.3 --- Chen and Smith Method and Experimental Results --- p.3-7 / Chapter 3.4 --- Concluding Remarks --- p.3-15 / Chapter 4 --- COMPATIBILITY OF THE DCT AND ICT / Chapter 4.1 --- Introduction --- p.4-1 / Chapter 4.2 --- The Discrete Cosine Transform (DCT) --- p.4 -2 / Chapter 4.3 --- The Family of Interger Cosine Transforms (ICT) --- p.4 -3 / Chapter 4.4 --- Analysis of Error Due to Different Forward and Inverse Transforms --- p.4 -8 / Chapter 4.4.1 --- First-Order Markov Process --- p.4-8 / Chapter 4.4.2 --- Separable Model --- p.4-10 / Chapter 4.4.3 --- Non-Separable Isotropic Model --- p.4-12 / Chapter 4.5 --- Results --- p.4-14 / Chapter 4.6 --- Concluding Remarks --- p.4 -18 / Chapter 5 --- ERROR BEHAVIOUR OF THE DCT AND THE ICT / Chapter 5.1 --- Introduction --- p.5 -1 / Chapter 5.2 --- Problem Identification --- p.5 -1 / Chapter 5.2.1 --- Error Distribution and Energy Due to Rounding Operation --- p.5-2 / Chapter 5.2.2 --- Error Distribution and Energy Due to Linear Transformation --- p.5-3 / Chapter 5.2.3 --- Estimation of Residual Error Energy --- p.5-6 / Chapter 5.3 --- Error Energy in the One-Dimensional Order-8 DCT System --- p.5-8 / Chapter 5.4 --- Error Energy in the One-Dimensional Order-8 ICT(4) System --- p.5-11 / Chapter 5.5 --- Error Energy in the Two-Dimensional Order-8 DCT System --- p.5-13 / Chapter 5.6 --- Error Energy in the Two-Dimensional Order-8 ICT(4) System --- p.5-16 / Chapter 5.7 --- Error Energy in Other Transform Systems --- p.5-19 / Chapter 5.7.1 --- Error Energy in the Two-Dimensional Order-16 DCT System --- p.5-20 / Chapter 5.7.2 --- Error Energy in the One-Dimensional Order-16 ICT(7) System --- p.5-21 / Chapter 5.7.3 --- Error Energy in the Two-Dimensional Order-16 ICT(7) System --- p.5 -21 / Chapter 5.8 --- Results --- p.5 -22 / Chapter 5.9 --- Concluding Remarks --- p.5 -24 / Chapter 6 --- CONCLUSIONS --- p.6-1 / Chapter 6.1 --- Summary of Work --- p.6-1 / Chapter 6.2 --- Contribution of the Work --- p.6-2 / Chapter 6.3 --- Recommendation for Further Work --- p.6-3 / Chapter 7 --- REFERENCES --- p.7 -1 / Chapter 8 --- APPENDIX / Chapter A.1 --- Separability of KLTs --- p.A -1 / Chapter A.2 --- Derivation of DCT and KLT DC Transformed Energy --- p.A -2 / First-Order Maikov Process --- p.A -2 / Separable Model --- p.A -3 / Non-Separable Isotropic Model --- p.A -4 / RESULTS

Hung, Kwok-Wah. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1991. / Bibliography: leaves 109-111. / ACKNOWLEDGEMENTS / ABSTRACT / Chapter CHAPTER 1 --- Overview of Packet Radio Networks --- p.1 / Chapter 1.1 --- Introduction --- p.2 / Chapter 1.2 --- Network Structure --- p.3 / Chapter 1.3 --- Channel Access Protocol --- p.3 / Chapter 1.4 --- Spatial Reuse --- p.5 / Chapter 1.5 --- Spread Spectrum --- p.6 / Chapter 1.6 --- Thesis Introduction --- p.8 / Chapter CHAPTER 2 --- Design Algorithms for Networks with Directional Antennas --- p.12 / Chapter 2.1 --- Introduction --- p.13 / Chapter 2.2 --- Problems in The MTCD/MDA Protocol --- p.14 / Chapter 2.3 --- The Simple Tone Sense (STS) Protocol --- p.15 / Chapter 2.4 --- The Variable Power Tone Sense (YPTS) Protocol --- p.18 / Chapter 2.5 --- Network Design Algorithms --- p.19 / Chapter 2.6 --- Network Design Example --- p.25 / Chapter 2.7 --- Simulation Results --- p.28 / Chapter 2.8 --- Chapter Summary --- p.31 / Chapter CHAPTER 3 --- The Coded Tone Sense Protocol --- p.44 / Chapter 3.1 --- Introduction … --- p.45 / Chapter 3.2 --- System Model and Code Assignment Algorithm --- p.46 / Chapter 3.3 --- Protocol Description --- p.48 / Chapter 3.4 --- Simulation Results --- p.49 / Chapter 3.5 --- Chapter Summary --- p.51 / Chapter CHAPTER 4 --- An Efficient Spreading Code Assignment Algorithm --- p.54 / Chapter 4.1 --- Introduction … --- p.55 / Chapter 4.2 --- Code Assignment and Graph Coloring --- p.55 / Chapter 4.3 --- Algorithm Description --- p.57 / Chapter 4.4 --- Results and Discussion --- p.59 / Chapter 4.5 --- Chapter Summary --- p.60 / Chapter CHAPTER 5 --- Fair and Efficient Transmission Scheduling --- p.64 / Chapter 5.1 --- Introduction --- p.65 / Chapter 5.2 --- The Scheduling Problem --- p.67 / Chapter 5.3 --- The Scheduling Algorithm --- p.68 / Chapter 5.4 --- Performance Analysis --- p.70 / Chapter 5.5 --- Results and Discussion --- p.72 / Chapter 5.6 --- Chapter Summary --- p.74 / Chapter CHAPTER 6 --- Staggered Multicast Protocol with Collision-Free Acknowledgement --- p.79 / Chapter 6.1 --- Introduction --- p.80 / Chapter 6.2 --- System Model --- p.83 / Chapter 6.3 --- Protocol Description --- p.84 / Chapter 6.4 --- Staggered Relay Broadcasting --- p.90 / Chapter 6.5 --- Simulation Results --- p.91 / Chapter 6.6 --- Chapter Summary --- p.92 / Chapter CHAPTER 7 --- Conclusion --- p.104 / Chapter 7.1 --- Summary --- p.105 / Chapter 7.2 --- Topics for Future Research --- p.107 / REFERENCES --- p.109

by Lo Kwok Tung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1989. / Bibliography: leaves [71-74]

by Pui-chiu Yip. / Thesis (M.Ph.)--Chinese University of Hong Kong, 1988. / Bibliography: leaves 92-94.

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