Several measurements may be used as error signals to determine how to appropriately control a sound field. These include pressure, particle velocity, energy density and intensity. In this thesis, numerical models are used to show which signals perform best in is free-field active noise control (ANC) using error sensors located in the near field of the sound sources. The second is equalization in a free field and a semi-free field. Minimized energy density total power output (MEDToPO) plots are developed; these indicate the maximum achievable attenuation for a chosen error sensor as a function of location. A global listening area equalization coefficient (GLAEC) is found to evaluate the performance of the equalization methods. It is calculated by finding the average of the spectral standard deviation of several frequency response measurements in a specified listening area. For free-field ANC employing error sensors located in the near field, pressure-based measurements perform the best. For free-field equalization over an extended listening region, total energy density performs best. Equalization of an extended listening region is more successful over a limited low-frequency bandwidth.

A control metric, the weighted sum of spatial gradients (WSSG), has been developed for use in active structural acoustic control (ASAC). Previous development of WSSG [1] showed that it was an effective control metric on simply supported plates, while being simpler to measure than other control metrics, such as volume velocity. The purpose of the current work is to demonstrate that the previous research can be generalized to plates with a wider variety of boundary conditions and on less ideal plates. Two classes of plates have been considered: clamped flat plates, and ribbed plates. On clamped flat plates an analytical model has been developed for use in WSSG that assumes the mode shapes are the product of clamped-clamped beam mode shapes. The boundary condition specific weights for use in WSSG have been derived from this formulation and provide a relatively uniform measurement field, as in the case of the simply supported plate. Using this control metric, control of radiated sound power has been simulated. The results show that WSSG provides comparable control to volume velocity on the clamped plate. Results also show, through random placement of the sensors on the plate, that similar control can be achieved regardless of sensor location. This demonstrates that WSSG is an effective control metric on a variety of boundary conditions. Ribbed plates were considered because of their wide use in aircraft and ships. In this case, a finite-element model of the plate has been used to obtain the displacement field on the plate under a variety of boundary conditions. Due to the discretized model involved, a numerical, as opposed to analytical, formulation for WSSG has been developed. Simulations using this model show that ASAC can be performed effectively on ribbed plates. In particular WSSG was found to perform comparable to or better than volume velocity on all boundary conditions examined. The sensor insensitivity property was found to hold within each section (divided by the ribs) of the plate, a slightly modified form of the flat plate insensitivity property where the plates have been shown to be relatively insensitive to sensor location over the entire surface of the plate. Improved control at natural frequencies can be achieved by applying a second control force. This confirms that ASAC is a viable option for the control of radiated sound power on non-ideal physical systems similar to ribbed plates.

This work investigates the application of active noise control (ANC) to speech. ANC has had success reducing tonal noise. In this work, that success was extended to noise that is not completely tonal but has some tonal elements such as speech. Limitations such as causality were established on the active control of human speech. An optimal configuration for control actuators was developed for a sphere using a genetic algorithm. The optimal error sensor location was found from exploring the nulls associated with the magnitude of the radiated pressure with reference to the primary pressure field. Both numerically predicted and experimentally validated results for the attenuation of single frequency tones were shown. The differences between the numerically predicted results for attenuation with a sphere present in the pressure field and monopoles in the free-field are also discussed.The attenuation from ANC of both monotone and natural speech is shown and a discussion about the effect of causality on the results is given. The sentence “Joe took father’s shoe bench out” was used for both monotone and natural speech. Over this entire monotone speech sentence, the average attenuation was 8.6 dB with a peak attenuation of 10.6 dB for the syllable “Joe”. Natural speech attenuation was 1.1 dB for the sentence average with a peak attenuation on the syllable “bench” of 2.4 dB. In addition to the lower attenuation values for natural speech, the pressure level for the word “took” was increased by 2.3 dB. Also, the harmonic at 420 Hz in the word “father’s” of monotone speech was reduced globally up to 20 dB. Based on the results of the attenuation of monotone and natural speech, it was concluded that a reasonable amount of attenuation could be achieved on natural speech if its correlation could approach that of monotone speech.

Thesis (M. A. (Communication Studies)) -- University of Limpopo, 2022 / The purpose of this study was to investigate the approach to land and unemployment as main electoral themes during 2019 elections in South Africa by the ANC and EFF. A qualitative, exploratory research was conducted to determine how these issues were articulated and approached using emotional and cognitive messages in the production of political content. This was to determine the implications of their use regarding issues of emphasis and ownership by political parties on the decision of constituencies. The hubs of data collection for this study were political street posters and Facebook advertisements. This study paid particular focus on the manners in which both parties framed the subjects of land and unemployment. Thus, thematic content analysis was used to determine the themes that emerged from the Facebook advertisements while semiotic analysis was applied on the data that emanated from street posters. The selection of the posters and Facebook political advertisements was guided by the issues the researcher intended to study which reflected on the ANC and EFF political advertisements. A total of 8 posters (N=8) were selected and analysed (4 for each party) and a total of 10 Facebook advertisements (5 for each party) were used for the generation of data in this study. A semi-structured interview was also conducted. The findings revealed that there are connections among political issues, images of politicians and the decision of voters. People vote based on these connections. The study therefore recommends that areas of content production need to be improved in the production of political advertisements, and that scholars need to improve the existing literature on political communication to educate the public (voters) about the persuasive strategies of the political parties

This study sought to determine if ANC and PMTCT services are utilized within the first trimester of pregnancy by the women in East Ekurhuleni sub-district. Quantitative descriptive research was conducted on 390 eligible pregnant women and data collection was done using structured questionnaires. The results indicated that women start ANC late despite their knowledge of first trimester as the best time to start ANC. Actions that would motivate them to start ANC early were explored and barriers were identified. / Health Studies / MA (Public Health)

The study was conducted to describe how socio-economic characteristics (SEC) of women affect their utilization of maternal healthcare services in Abuja Municipal Areas Council (AMAC) in Abuja Nigeria. A non-experimental, facility-based cross-sectional survey was done. Data was collected using structured interviewer administered questionnaire in 5 district hospitals in AMAC. Sample size of 384 was calculated a priori based on the assumption that 50% of the target population utilized maternal healthcare services during their last pregnancy. Equal allocation of samples per facility was done. The ANC register was used as the sampling frame and proportionate allocation of samples per clinic days was undertaken in each facility. Data analysis included descriptive statistics, cross tabulations and measures of inequality. Logistic regression analysis was used to test the hypothesized relationship between socioeconomic characteristics (predictors) and maternal healthcare service utilization. Other than birth order that showed consistent effect, the results of this study indicated that the predictive effect (predisposing and enabling factors) of the SEC of women included in this study (age, education, birth order, location of residence, income group and coverage by health insurance) on maternal healthcare service utilization were not consistent when considered independently (bivariate analysis) as opposed to when considered together through logistic regression. In addition, the study revealed that there was inequality in the utilization of maternal healthcare services (ante-natal care - ANC, delivery care and post natal care - PNC, and contraceptive services) among women with different SEC, and the payment system for maternal healthcare services was regressive. Addressing these predictors in the natural co-existing state (as indicated by the logistic regression) is essential for equitable access and utilization of healthcare during pregnancy, delivery and the postnatal period, and for contraceptive services in AMAC, Abuja Nigeria. Targeted policy measures and programme actions guided by these findings are recommended to optimise returns on investment towards achieving national and global goals on maternal health in Nigeria / Health Studies / D. Litt. et Phil. (Health Studies)

Thesis MA (Political Science. International Studies))--Stellenbosch University, 2008. / Liberation movements came into being across the entire African continent as a political response to colonisation. However, Africa has in this field, as in so many others, been largely understudied, in comparison to revolutionary movements in South America and South East Asia. While many case studies on specific liberation movements exist, very few are comparative in nature. This study will do precisely that using the framework of Thomas H. Greene. The resistance movements in South Africa and Zimbabwe, then Rhodesia, consisted of several organisations, but the ones that emerged as the most powerful and significant in the two countries were the ANC and ZANU respectively. Although their situations were similar in many ways, there were other factors that necessarily led to two very different liberation struggles. This study looks closer at these factors, why they were so, and what this meant for the two movements. It focuses on the different characteristics of the movements, dividing these into leadership, support base, ideology, organisation, strategies and external support. All revolutionary movements rely on these factors to varying degrees, depending on the conditions they are operating under. The ANC and ZANU both had to fight under very difficult and different circumstances, with oppressive minority regimes severely restricting their actions. This meant that the non-violent protests that initially were a great influence for the leadership of both movements – especially with the successes of Mahatma Gandhi in South Africa and India, inevitably had to give way to the more effective strategies of sabotage and armed struggle. Like other African resistance movements, nationalism was used as the main mobilising tool within the populations. In South Africa the struggle against apartheid was more complex and multidimensional than in Zimbabwe. Ultimately successful in their efforts, the ANC and ZANU both became the political parties that assumed power after liberation. This study does not extend to post-liberation problems.

The study was conducted to describe how socio-economic characteristics (SEC) of women affect their utilization of maternal healthcare services in Abuja Municipal Areas Council (AMAC) in Abuja Nigeria. A non-experimental, facility-based cross-sectional survey was done. Data was collected using structured interviewer administered questionnaire in 5 district hospitals in AMAC. Sample size of 384 was calculated a priori based on the assumption that 50% of the target population utilized maternal healthcare services during their last pregnancy. Equal allocation of samples per facility was done. The ANC register was used as the sampling frame and proportionate allocation of samples per clinic days was undertaken in each facility. Data analysis included descriptive statistics, cross tabulations and measures of inequality. Logistic regression analysis was used to test the hypothesized relationship between socioeconomic characteristics (predictors) and maternal healthcare service utilization. Other than birth order that showed consistent effect, the results of this study indicated that the predictive effect (predisposing and enabling factors) of the SEC of women included in this study (age, education, birth order, location of residence, income group and coverage by health insurance) on maternal healthcare service utilization were not consistent when considered independently (bivariate analysis) as opposed to when considered together through logistic regression. In addition, the study revealed that there was inequality in the utilization of maternal healthcare services (ante-natal care - ANC, delivery care and post natal care - PNC, and contraceptive services) among women with different SEC, and the payment system for maternal healthcare services was regressive. Addressing these predictors in the natural co-existing state (as indicated by the logistic regression) is essential for equitable access and utilization of healthcare during pregnancy, delivery and the postnatal period, and for contraceptive services in AMAC, Abuja Nigeria. Targeted policy measures and programme actions guided by these findings are recommended to optimise returns on investment towards achieving national and global goals on maternal health in Nigeria / Health Studies / D. Litt. et Phil. (Health Studies)

This study aimed to assess the magnitude, trends and determinants of intrapartum stillbirths in the public health facilities in Addis Ababa. A case-control study design was used along with quantitative data collection methods. Obstetric care data on key variables were collected from medical records of 728 cases and 1551 controls in the public health facilities during July 1, 2010 and June 30, 2015. Data were analysed using SPSS version 24 to determine associations and risk factors against intrapartum stillbirth. HMIS data from different sources were further analysed for the same period to determine trends of stillbirth in the public health facilities of Addis Ababa. Findings from this study showed a staggering high prevalence of stillbirth at an average rate of 28 per 1000 births during the period 2010-2015. This figure was comparable with the population level prevalence of prenatal death in Addis Ababa which was 30 per 1000 birth (Central Statistical Agency 2011:115). No statistically significant associations were revealed against the effects of maternal medical conditions including diabetes, hypertension, cardiac and renal diseases and key socio-demographic variables including age, parity and marital status, and intrapartum stillbirth. On the contrary, HIV and syphilis infections, foetal presentations, multiple pregnancy and the frequency of ANC visits during the index pregnancy had statistically significant associations with intrapartum stillbirth. Furthermore, low FHR, non-vertex foetal presentations and ruptured cervical membrane on admission to labour were among risk factors for intrapartum stillbirth. Similarly, women in the stillbirth group received substandard care regarding the timely assessment of foetal decent, cervical dilatation, labour induction, and episiotomy care compared to women in the livebirth group. Obstetrical complications including obstructed labour, eclampsia and preeclampsia were more common among women in the intrapartum stillbirth group indicating that the above variables were key determinant of intrapartum stillbirth. These findings suggest that poor quality of obstetric care during labour and childbirth were the underlying risk factors for intrapartum stillbirth. In conclusion, strategies to overhaul the obstetric care practices in the public health facilities through skills building, accurate use of labour monitoring tools, close supervisions, accurate classification of stillbirth, proper documentation, and ongoing research efforts. / Health Studies / D. Litt. et Phil. (Health Studies)

MPM / Oliver Tambo Institute of Governance and Policy Studies / Among the rights in the Bill of Rights contained in the South African Constitution is the right to access to adequate housing. This right is bound up with other rights in the Constitution, including the right to have their human dignity respected, and the right to water and health care. The right to adequate housing is also comprised in several international human rights declarations, including the Universal Declaration of Human Rights by the United Nations. However, the right to access to adequate housing involves more than just a shelter, but includes a number of other elements such as security of tenure and access to basic services and facilities. Housing must be affordable and accessible. It must be safe and habitable and be socially acceptable. Furthermore, adequate housing is well located with respect to economic and other opportunities. The provision of housing and basic services has been the focus of the ANC-led government since 1994 and a major portion of municipal resources has been dedicated to providing water and sanitation to mainly the poorest families, while over 1,5 million state-subsidized homes have been delivered. While the scale of delivery has been inspiring, has it really impacted on the lives of people in remote communities? A qualitative research design was utilised in this study as it was considered the most appropriate method to gather data and answer the research questions. In this study, data were gathered using unstructured in-depth interviews and focused group discussions. As part of the major findings, this research has revealed that the municipality does not have a housing provision policy though is building RDP houses with the support of a provincial government in line with the Housing Act. Through the provision of these low cost houses, the municipality has overcome many housing delivery challenges and that it has to date worked as a good governance strategy to attract the poor. Research conducted in the Musina Municipality in the Limpopo Province regarding the realization of the right to access adequate housing reveals that the right to adequate housing has, at best, only been partly realized as part of the major findings. In addition to interviews with office bearers and municipal officials, 120 households were interviewed (of which half were from self-built houses and half were residing in ‘RDP’ houses) concerning their understanding and experience of the right to access to adequate housing in the municipality. The study discloses v that the structures do not meet the criteria for adequate housing and the provision of water and sanitation remains a challenge in some rural areas. Access to health and education facilities is poor, due to the low densities and vast distances between settlements. This research recommends a plethora of good initiatives which could be seen as a way forward towards an improved adequate housing delivery mechanism which is also regulated. A need for mixed use integrated housing delivery through formal settlements is recommended in order to maximize the available financial resources and to also strengthen the intergovernmental relations through multi-stakeholder support. / NRF