HIV/AIDS is already the leading cause of death worldwide (Unicef et al., 2004:10) with more than 5 million people out of a total of 46 million South Africans that were HIV positive in 2004, giving a total population prevalence rate of 11 per cent (Dorrington et al., 2004:1). Many people infected do not have access to even the basic drugs needed to treat HIV-related infections and other conditions (Wikipedia, 2004:3). The relative high price of many of the antiretroviral (ARV) drugs and diagnostics on the other hand are one of the main barriers to their availability in developing countries (Unicef et al., 2004:77). ARV drugs registered in South Africa include the Nucleoside/Nucleotide Reverse Transcriptase Inhibitors (NRTIs), Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) and Protease Inhibitors (PIs) (MCC, 2004:1). The objective of this study was to review, analyse and interpret the prescribing patterns of antiviral drugs, with special reference to antiretroviral drugs, in the private health care sector in South Africa by using a medicine claims database. A quantitative, retrospective drug utilisation review was performed. The data ranging from 1 January 2001 to 31 December 2001, 1 January 2002 to 31 December 2002, and 1 January 2004 to 31 December 2004 were used, dividing each year into three four-month periods, namely January to April, May to August, and September to December. It was found that 0.38 per cent (n=1 475 380) for 2001, 0.72 per cent (n=2 076 236) for 2002, and 1.68 per cent (n=2 595 254) for 2004 of all studied prescriptions for the research periods 2001, 2002, and 2004 respectively, contained ARV drugs. ARV drugs constituted 0.33 per cent (n=2 951 326) for 2001, 0.87 per cent (n=4 042 145) for 2002, and 1.92 per cent (n=5 305 882) for 2004 of the total number of medicine items prescribed for the study years 2001, 2002 and 2004 respectively. The total cost of ARV drugs amounted to R4 990 784.29, thus constituting 1.31 per cent of the total cost (R379 708 489) of all medicine items on the database for 2001, increased to R18 235 075.75, thus constituting 3.03 per cent of the total cost (R601 350 325) of all medicine items on the database for 2002, and increased to R34 714 483.64, thus constituting 5.25 per cent of the total cost (R661 223 146) of all medicine items on the database for 2004. It was found that 35.31 per cent (n=5 599) for 2001, 52.68 per cent (n=15 004) for 2002, and 74.27 per cent (n=43 482) for 2004 of all studied antiviral prescriptions for the research periods 2001, 2002, and 2004 respectively, contained ARV drugs. ARV drugs constituted 46.25 per cent (n=21 183) for 2001, 70.20 per cent (n=50 246) for 2002, and 85.87 per cent (n=118 718) for 2004 of the total number of antiviral medicine items prescribed for the study years 2001, 2002 and 2004 respectively. The total cost of ARV medicine items, represented 67.33 per cent (n=R4 990 784.29) during 2001, 84.72 per cent (n=R18 235 075.75) during 2002, and 91.20 per cent (n=R34 714 483.64) during 2004 of the total cost of all antiviral medicine items claimed through the database (n=R7412577.73 for 2001, n=R21523365.56 for 2002, and n=R38 064 347.38 for 2004). The average cost per ARV medicine items for 2004 increased from R317.93i190.80 for the period January to April to R369.2W219.50 for the period May to August, and decreased to R324.79±212.48 for the period September to December and resulted in a cost saving of R41 044.35 for the period May to August versus September to December for the ARV medicine items. The implementation of the pricing regulations could thus be a possible reason for this cost saving, due to fact that the single exit price only came into effect from May 2004. The weighted average number of ARV medicine items per prescription was 1.75*0.31 for 2001, increased to 2.35±0.03 to 2002 and remained stable on 2.35±0.02 for 2004. It was found that majority of prescriptions contained more combination ARV medicine items than single ARV medicine items, ranging from 6 834 (69.76 per cent; n=9 796) prescriptions containing combination ARV medicine items in 2001 and 32 941 (93.39 per cent; n=35 271) prescriptions containing combination ARV medicine items in 2002 to 98 805 (96.93 per cent; n=101 938) prescriptions containing combination ARV medicine items in 2004. Lastly, it was perceived that didanosine was the active ingredient with the largest prevalence for all three four-month periods of 2001 and also for the periods January to April and May to August of 2002, whilst efavirenz represented the active ingredient with the largest prevalence for the period September to December of 2002, and also for all three four-month periods of 2004. Didanosine represented the active ingredient with the highest total cost for the period January to April of 2001, whilst the combination of lamivudine/zidovudine represented the active ingredient with the highest total cost for the periods May to August and September to December of 2001, and also for all three-four month periods of 2002 and 2004. Nelfinavir has the highest average cost for period January to April of 2001, ritonavir for period May to August of 2001, and saquinavir mesylate for period September to December of 2001. Nelfinavir has the highest average cost for all three-four month periods of 2002, while didanosine has the highest average cost for all three four-month periods of 2004. / Thesis (M.Pharm. (Pharmacy Practice))--North-West University, Potchefstroom Campus, 2006

This dissertation studies poverty and the economics of child-headed and grandmother-headed households in Sebokeng. The study takes interest in five main areas, namely, poverty, unemployment, child and grandmother-headed households, the state of poverty and unemployment in Sebokeng as well as the living conditions of child and grandmother-headed households in Sebokeng. The approach in this dissertation was to define and measure poverty and unemployment and to determine the poor population of Sebokeng. This was done by making use of household level indicators. Poverty was measured by employing the following indicators: the Household Subsistence level (HSL) as poverty line, the head count index, the poverty gap and the dependency ratio. A comparison was done between Sebokeng and Bophelong. Sebokeng has a higher level of poverty (85%) than that of Bophelong (67%) while the unemployment rates (27%) is lower than that of Bophelong (31%). Most indicators (level of education, income, expenditure) prove that Bophelong is better off compared to Sebokeng. This dissertation takes further interest in comparing child and grandmother-headed households to “normal” households in Sebokeng. The study found that the main source of income for child-headed households is foster and child support grants (54%) while pension grants serve as the main source of income for both grandmother-headed households and “normal” households (65%).The study therefore proves that child-headed households are worse off financially and otherwise in comparison to grandmother-headed and “normal” households. If more social worker assistance was available to these orphans in the form of assistance with the application for identity documents and birth certificates at the Department of Home Affairs, these orphans would not be as worse-off as was found in this study. The dissertation concludes that the depth of poverty in child-headed households is thus greater than that of grandmother-headed and “normal” households, and it recommends that government should take further steps to reduce the unemployment rate by paying attention to the preferred skills of the population of Poverty and the economics of child and grandmother-headed households in Sebokeng. Sebokeng by offering training to enhance those skills. Food gardening projects should be organised so that the poor can sustain themselves and earn an income in the process. The dissertation also recommends that government should take more interest in improving the lives of these orphans by encouraging them to go to school and in obtaining identity documents. This can be possible through the assistance of social workers as these two elements can open many doors to a better life for these orphans. / Thesis (M.Com. (Economics))--North-West University, Vaal Triangle Campus, 2011

This dissertation studies poverty and the economics of child-headed and grandmother-headed households in Sebokeng. The study takes interest in five main areas, namely, poverty, unemployment, child and grandmother-headed households, the state of poverty and unemployment in Sebokeng as well as the living conditions of child and grandmother-headed households in Sebokeng. The approach in this dissertation was to define and measure poverty and unemployment and to determine the poor population of Sebokeng. This was done by making use of household level indicators. Poverty was measured by employing the following indicators: the Household Subsistence level (HSL) as poverty line, the head count index, the poverty gap and the dependency ratio. A comparison was done between Sebokeng and Bophelong. Sebokeng has a higher level of poverty (85%) than that of Bophelong (67%) while the unemployment rates (27%) is lower than that of Bophelong (31%). Most indicators (level of education, income, expenditure) prove that Bophelong is better off compared to Sebokeng. This dissertation takes further interest in comparing child and grandmother-headed households to “normal” households in Sebokeng. The study found that the main source of income for child-headed households is foster and child support grants (54%) while pension grants serve as the main source of income for both grandmother-headed households and “normal” households (65%).The study therefore proves that child-headed households are worse off financially and otherwise in comparison to grandmother-headed and “normal” households. If more social worker assistance was available to these orphans in the form of assistance with the application for identity documents and birth certificates at the Department of Home Affairs, these orphans would not be as worse-off as was found in this study. The dissertation concludes that the depth of poverty in child-headed households is thus greater than that of grandmother-headed and “normal” households, and it recommends that government should take further steps to reduce the unemployment rate by paying attention to the preferred skills of the population of Poverty and the economics of child and grandmother-headed households in Sebokeng. Sebokeng by offering training to enhance those skills. Food gardening projects should be organised so that the poor can sustain themselves and earn an income in the process. The dissertation also recommends that government should take more interest in improving the lives of these orphans by encouraging them to go to school and in obtaining identity documents. This can be possible through the assistance of social workers as these two elements can open many doors to a better life for these orphans. / Thesis (M.Com. (Economics))--North-West University, Vaal Triangle Campus, 2011

På bullriga arbetsplatser använder personal ofta hörselskydd med inbyggda högtalare för att lyssna på exempelvis musik i underhållningssyfte. Om användaren lyssnar på höga ljudnivåer under långa perioder kan bullerskador uppstå i dennes öron. Enligt lagstiftning måste nivån därför begränsas i förebyggande syfte. Bullernivån är ett genomsnitt av de ljudnivåer användaren exponerats för under en arbetsdag. Användaren måste vila öronen om gränsvärdet för bullernivån nås.Om man utnyttjar att det är ett genomsnitt kan användaren tillåtas lyssna på en hög ljudnivå under en begränsad tid för att sedan sänka den. Det går att bevara både säkerheten och lyssningsupplevelsen om en sänkning införs långsamt. Detta arbete beskriver hur en algoritm till en digital signalprocessor kan konstrueras för att reglera ljudnivån.Målsättningen var att algoritmen skulle skydda användarens hörsel utan att försämra lyssningsupplevelsen, och utan att förbruka mer energi än nödvändigt. I algoritmen ingick en prediktor som predikterar mängden buller användaren riskerar att utsättas för, om denne fortsätter lyssna på samma nivå.Långsamma sänkningar av ljudnivån kan då utföras i tid innan gränsvärdet nås. Det visade sig att algoritmen endast behövde ett fåtal samplingar per sekund för att skatta och reglera ljudnivån tillräckligt precist, vilket reducerade energiförbrukningen.Resultatet visar möjligheten att kombinera målen för säkerhet, lyssningsupplevelse och energieffektivitet i hörselskydd. Algoritmen implementerades inte på ett skarpt system.Den hade enbart tillgång till ljudsignalen användaren ämnade lyssna på i underhållningssyfte. / In noisy workplaces the staff are often using hearing protectors with built-in speakers for entertainment purposes. Prolonged exposure to loud sound levels can cause damage to the user’s ears. The legislation requires therefore a limiting mechanism for the speakers. The noise level is defined as the average of the sound levels the user has been exposed to during a working day. If the noise threshold is reached the user has to rest his ears. This definition can be exploited to allow the user to listen to a loud sound level for a limited time and then lowering it. If the sound level is lowered slowly, it is possible to preserve both safety and listening experience. This work describes how an algorithm can be designed for a digital signal processor with the purpose of controlling the sound level. The aim was to protect the user's hearing without spoiling the listening experience, and without consuming more power than necessary. The algorithm design included a predictor that predicts the amount of noise the user risk being subjected to, if he continues to listen at the same level. Slow reduction of the sound level can then be carried out in time before the noise threshold is reached. It turned out that the algorithm only needed a few samples per second to estimate and control the sound level sufficiently precisely, this reduced the power consumption. The results show that it is possible to combine the objectives for safety, listening experience and power consumption in hearing protectors. The algorithm was not implemented in a real system. The algorithm had only access to the audio signal which the user intended to listen to for entertainment purposes.

Orthogonal Frequency Division Multiplexing (OFDM) and Single Carrier Block Transmissions (SCBT) are located at the two opposite edges of block transmission concept. In this thesis a system which lies between OFDM and SCBT is proposed. The new system, namely Block Transmissions on Orthogonal Carriers (BTOC), can be considered as a hybrid form of OFDM and SCBT. BTOC system is investigated under the redundant filterbank precoders and equalizers framework. Peak to average power ratio (PAPR) of BTOC is formulated and compared with the PAPRs of OFDM and SCBT. Effect of frequency offset for BTOC is investigated and comparison between OFDM, SCBT, and BTOC is presented. Simulation results of Zero Padded OFDM (ZP-OFDM), SCBT, and BTOC are included.

Distortion-based crest factor reduction (CFR) algorithms were studied in orthogonal frequency division multiplexing (OFDM) and multiple-input multiple-output (MIMO) OFDM systems to reduce the nonlinear distortion and improve the power efficiency of the transmitter front-end. First, definitions of peak-to-average-power ratio (PAR) were clarified based on the power efficiency improvement consideration in the MIMO-OFDM systems. Next, error vector magnitude (EVM) was used as the in-band performance-evaluating metric. Statistical analysis of EVM was performed to provide concrete thresholds for the amount of allowable distortions from each source to meet EVM requirements in the standard. Furthermore, an effective CFR technique, constrained clipping, was proposed to drastically reduce the PAR while satisfying any given in-band EVM and out-of-band spectral mask constraints. Constrained clipping has low computational complexity and can be easily extended to the multiple-user OFDM environment. Finally, signal-to-noise-and-distortion ratio (SNDR) analysis for transceiver nonlinearities in the additive white Gaussian noise channel was investigated. An analytical solution was presented for maximizing the transceiver SNDR for any given set of nonlinear transmitter polynomial coefficients. Additionally, mutually inverse pair of transceiver nonlinearities was shown to be SNDR-optimal only in the noise-free case.

In this thesis two different problems in distributed sensor networks are considered. Part I involves optimal quantiser design for decentralised estimation of a two-state hidden Markov model with dual sensors. The notion of optimality for quantiser design is based on minimising the probability of error in estimating the hidden Markov state. Equations for the filter error are derived for the continuous (unquantised) sensor outputs (signals), which are used to benchmark the performance of the quantisers. Minimising the probability of filter error to obtain the quantiser breakpoints is a difficult problem therefore an alternative method is employed. The quantiser breakpoints are obtained by maximising the mutual information between the quantised signals and the hidden Markov state. This method is known to work well for the single sensor case. Cases with independent and correlated noise across the signals are considered. The method is then applied to Markov processes with Gaussian signal noise, and further investigated through simulation studies. Simulations involving both independent and correlated noise across the sensors are performed and a number of interesting new theoretical results are obtained, particularly in the case of correlated noise. In Part II, the focus shifts to the detection of faults in helicopter transmission systems. The aim of the investigation is to determine whether the acoustic signature can be used for fault detection and diagnosis. To investigate this, statistical change detection algorithms are applied to acoustic vibration data obtained from the main rotor gearbox of a Bell 206 helicopter, which is run at high load under test conditions.

The performance and safety assessment of geo-structures is strongly affected by uncertainty; that is, both due a subjective lack of knowledge as well as objectively present and irreducible unknowns. Due to uncertainty in the non-linear variation of the matric suction induced effective stress as a function of the transient soil-atmosphere boundary conditions, the unsaturated state of the subsoil is generally not accounted for in a deterministic slope stability assessment. Probability theory, accounting for uncertainties quantitatively rather than using "cautious estimates" on loads and resistances, may aid to partly bridge the gap between unsaturated soil mechanics and engineering practice. This research investigates the effect of uncertainty in soil property values on the stability of unsaturated soil slopes. Two 2D Finite Element (FE) programs have been developed and implemented into a parallelised Reliability-Based Design (RBD) framework, which allows for the assessment of the failure probability, failure consequence and parameter sensitivity, rather than a deterministic factor of safety. Utilising the Random Finite Element Method (RFEM), within a Monte Carlo framework, multivariate cross-correlated random property fields have been mapped onto the FE mesh to assess the effect of isotropic and anisotropic moderate heterogeneity on the transient slope response, and thus performance. The framework has been applied to a generic slope subjected to different rainfall scenarios. The performance was found to be sensitive to the uncertainty in the effective shear strength parameters, as well as the parameters governing the unsaturated soil behaviour. The failure probability was found to increase most during prolonged rainfall events with a low precipitation rate. Nevertheless, accounting for the unsaturated state resulted in a higher slope reliability than when not considering suction effects. In a heterogeneous deposit failure is attracted to local zones of low shear strength, which, for an unsaturated soil, are a function of both the spatial variability of soil property values, as well as of the soil-water dynamics, leading to a significant increase in the failure probability near the end of the main rainfall event.

abstract: The focus of the study was to identify secondary school students' difficulties with aspects of linearity and linear functions, and to assess their teachers' understanding of the nature of the difficulties experienced by their students. A cross-sectional study with 1561 Grades 8-10 students enrolled in mathematics courses from Pre-Algebra to Algebra II, and their 26 mathematics teachers was employed. All participants completed the Mini-Diagnostic Test (MDT) on aspects of linearity and linear functions, ranked the MDT problems by perceived difficulty, and commented on the nature of the difficulties. Interviews were conducted with 40 students and 20 teachers. A cluster analysis revealed the existence of two groups of students, Group 0 enrolled in courses below or at their grade level, and Group 1 enrolled in courses above their grade level. A factor analysis confirmed the importance of slope and the Cartesian connection for student understanding of linearity and linear functions. There was little variation in student performance on the MDT across grades. Student performance on the MDT increased with more advanced courses, mainly due to Group 1 student performance. The most difficult problems were those requiring identification of slope from the graph of a line. That difficulty persisted across grades, mathematics courses, and performance groups (Group 0, and 1). A comparison of student ranking of MDT problems by difficulty and their performance on the MDT, showed that students correctly identified the problems with the highest MDT mean scores as being least difficult for them. Only Group 1 students could identify some of the problems with lower MDT mean scores as being difficult. Teachers did not identify MDT problems that posed the greatest difficulty for their students. Student interviews confirmed difficulties with slope and the Cartesian connection. Teachers' descriptions of problem difficulty identified factors such as lack of familiarity with problem content or context, problem format and length. Teachers did not identify student difficulties with slope in a geometric context. / Dissertation/Thesis / Ph.D. Curriculum and Instruction 2011

Nos últimos anos, com a aceleração da globalização, tem-se intensificado a atividade de análise e avaliação de investimentos. Dentre as diversas técnicas de mensuração de valor e risco, mereceu especial destaque as ferramentas de avaliação de empresas, em razão da significativa profusão de negociações de e entre empresas, que inclui grande número de fusões aquisições e parcerias. Em diferentes segmentos empresas privadas de capital fechado, passam a ser alvo de grandes companhias ou vislumbram vir a ser, o que traz a necessidade ao empresariado de saber qual o valor do seu negócio, qual o valor mínimo aceitável em uma negociação, seja de venda ou de compra de investimentos. Estas necessidades justificam a busca de ferramenta de valoração. Diante disto, este trabalho visa identificar, e discutir os principais aspectos relacionados à valoração de empresas. No levantamento bibliográfico foram identificados os principais modelos de valoração onde foram criticados, apontando limitações ou desvantagens; procurou-se identificar, dentre eles, o que se adaptaria para avaliar uma empresa de capital fechado dada a limitação de informações possíveis de serem levantadas na empresa, que fosse mais referendado pelos estudiosos e o mais utilizado neste momento. Optou-se então pelos modelos de Fluxo de Caixa Descontado (FCD) e Valor Econômico, comparando-os ao Valor Patrimonial Contábil. apresentando-se à empresa e acionistas um preço de referência para que possam iniciar negociações de compra ou venda de parte ou todo do negócio. No segmento supermercadista, nos últimos anos, houve grandes negociações, passando para um nível de concentração das 5 maiores redes de 61% do mercado nacional. No estudo de caso, realizado em uma empresa do ramo de supermercados, foi feito o levantamento dos dados históricos dos últimos 5 anos, e feitas as projeções para os próximos seis exercícios, sendo calculados ou estimados, também: o beta do setor, o ROIC, o WACC, o CAPM, o Capital Operacional Investido, o Spread e a composição do capital atual. Após aplicação das premissas e cálculo do período de projeção, foi calculado o valor da perpetuidade, adicionando-o aos dois modelos de avaliação, e com isso chegou-se a um mesmo valor de valoração da empresa, que confirmaram as afirmações encontradas na bibliografia. Após comparou-se o resultado da avaliação pelo FCD e pelo Valor Econômico com o valor Patrimonial Contábil sem ajustes, apresentando assim para a empresa uma ferramenta para avaliações ou projeções de cenários e a discrepância entre os valores contábeis e econômicos da empresa. / In the last years, due to the acceleration on globalization, the activity of analysis and evaluation of investments has been intensified. Among several techniques of measurement of value and risk, the tools for firm evaluation has got special notice for the reason that it has been a meaningful profusion and partnerships. In different segments, private owned companies become or are willing to become the target of big companies and so the entrepreneurs have the necessity to know the minimum value of their businesses in transactions of buying or selling investments. That necessity justifies the search for business valuation resources. Thus, this paper aims at identify and discuss the main aspects related to business valuation. In the bibliographic search the main models of business valuation resources were identified and passed judgment on their limitations or disadvantages. An attempt on identifying one among those resources which would adapt for evaluating a privately owned company and which would be referenced by scholars and most used at the moment was made. The difficulty found was due to limitation of possible information gathering from firms. The chosen alternative was the Discounted Cash Flow models – DCF – and Economic Value in comparison to Accounting Patrimonial Value to show the company and shareholders a referential price to start transactions of buying and selling of part or the whole business. In the supermarket segment, in the last years, there were huge negotiations ending up in a concentration of five big chains which represent 61% of Brazilian market. A case study carried in a supermarket gathered historical data from the last 5 years and from those, projections for the next 6 ones were made calculating the sector beta, ROIC, WACC, CAPM and the Operational Capital invested, Spread e the composition of updated capital. After applying the predictions and calculating the projection period, perpetual value was calculated by adding that to two models of appraisal and then getting to the same value of assessment which confirm the statements in the review of bibliography. Afterwards the result of the assessment was compared to DCF and to Economic Value with Accounting Patrimonial Value without adjustments featuring an evaluating or projecting scenarios and the discrepancy between accounting values and economic values within firms.