A social-ecological investigation into urban domestic gardens and avifauna in medium-sized towns of the Eastern Cape, South Africa
- Authors: Tricam, Shayla
- Date: 2020
- Subjects: Urban ecology (Biology) -- South Africa , Biotic communites -- South Africa , Gardens -- South Africa -- Managemenet , Birds – Ecology – South Africa , Gardening to attract birds -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/145314 , vital:38427
- Description: Urban domestic gardens are an often overlooked component of urban green infrastructure, despite their potential to contribute to the preservation of urban biodiversity. As opposed to public greenspaces, private gardens are individually owned and managed, thus act as social-ecological systems, where the cumulative actions of urban residents can scale up to influence ecological patterns and processes on a larger scale. The diversity of fauna and flora within urban gardens provide a range of ecosystem goods and services, as well as less tangible benefits in the form of recreation, education and culture. However, little is known about the contribution of urban domestic gardens to urban biodiversity and its potential conservation value in South Africa. This study investigated urban domestic gardens along a socio-economic gradient in two medium-sized towns, Grahamstown and Port Alfred in the Eastern Cape, South Africa. This study found distinct differences among urban resident garden management practices as well as the avifauna which were seen within the gardens across the socio-economic gradient. The Garden Management Intensity index was higher within affluent households compared to other socio-economic levels, with subsequent management scores not differing statistically along the gradient. While there was variation within garden management practices, as well as the number of residents who participated in supplementary bird feeding, little variation was seen in the activities which were enjoyed by the residents, indicating numerous benefits the garden environment provides for all urban residents. The bird community composition along the socio-economic gradient displayed patterns directly reflecting the “luxury effect”, where households with a higher socio-economic status had harbour gardens with greater levels of biodiversity. This study showed that affluent gardens displayed far greater diversity, richness and abundance of urban birds. Multivariate analyses confirmed the patterns by highlighting a distinct bird community in the affluent zone, compared to other two socio-economic zones, which housed a second bird community. Furthermore, the main driver of the bird community composition was dominated by vegetation complexity, most notably tree cover within the gardens. Therefore, this study highlighted that patterns of ecological inequality are highly evident in medium-sized towns in South Africa, where older, affluent suburbs households display greater diversity and abundance of birdlife, compared to subsequent socio-economic zones within the study. Prioritisation with regards to the benefits a garden environment brings to urban residents in terms of a connection to nature, access to urban greenery, and relationship to urban wildlife is vital and should be promoted and planned for across all socio-economic zones.
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- Date Issued: 2020
Assessing community structure and trophic interrelationships in three differently impacted headwater streams in the AmatholeWinterberg freshwater ecoregion, South Africa
- Authors: Matomela, Nonjabulo Happy
- Date: 2020
- Subjects: Stream ecology -- South Africa -- Eastern Cape , Freshwater animals -- Ecology -- South Africa -- Eastern Cape , Kat River (South Africa) -- , Lushington River (South Africa) , Elands River (South Africa) , Eyre River (South Africa) , Food chains (Ecology) -- South Africa -- Eastern Cape , Water quality -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/147653 , vital:38658
- Description: Afromontane regions represent some of the highly threatened ecosystems on the planet as they harbour endemic and often relic freshwater fauna. These ecologically sensitive ecosystems have been altered by multiple impacts, including invasion by non-native fishes, replacement of diverse indigenous vegetation with monoculture plantations, agricultural and mining activities, hydrological modifications, and degradation of instream habitats, with potential detrimental effects on aquatic community structures and food web dynamics. The aim of the present study was to compare spatio-temporal patterns of macroinvertebrate and fish communities as well as food web dynamics in three differently impacted headwater tributaries of the Kat River in the Amathole-Winterberg freshwater ecoregion in the Eastern Cape Province of South Africa. The upper Kat River catchment was the ideal model for purposes of the present study as it contains streams with varying degrees of human impact. The streams considered in the present study were (i) the Eyre River which was considered to closely represent near-natural conditions as it is the least impacted stream in this catchment, with the riparian zone dominated by relatively intact and diverse native woody vegetation, (ii) the Elands River whose catchment has been altered by agricultural activities, and (iii) the Lushington River, whose riparian zone has been heavily invaded by black wattle. The three headwater streams were generally distinguished based on the physical-chemical variables. The Elands River was characterised by high conductivity and total dissolved solids (TDS). In addition, the Elands River was more alkaline and relatively warmer than the other two rivers. This suggested the negative influence of agriculture activities on the water quality in the Elands River. In general, the Lushington and Eyre rivers had comparable physical and chemical variables. However, the Lushington River was generally characterised by low streamflow, likely as a consequent of black wattle which is known for altering hydrological regimes of streams .The Eyre River and Lushington River were comparable in terms of macroinvertebrate richness and diversity, whereas the Elands River was characterised by low macroinvertebrate diversity and richness. Redundancy analysis indicated that the macroinvertebrate communities were mostly influenced by seasonality, with land-use accounting for a small but significant difference in community composition. In comparison, the generalised linear mixed-effects models (GLMMs) showed that chubbyhead barb abundance was significantly influenced by land-use patterns. Evaluation of food web dynamics using stable isotope analysis revealed that the food web structure in the three rivers differed substantially as a result of land-use. Specifically, the Eyre River was characterised by less variation in stable isotope values of basal food sources and consequently, the consumer groups had a narrow isotopic breadth. In contrast, the Elands River was characterised by a wide variation in basal food sources and therefore, a wider isotopic breadth for consumers. The Lushington River was spatially variable in terms of basal sources and isotopic breadth for consumers. The study concluded that food webs and trophic interrelationships were a more informative indicator of land-use than community structure was in evaluating the impact of land-use patterns on aquatic communities. In addition, future studies should seek to investigate food webs interrelationships in addition to community structure to infer a more conclusive river assessment.
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- Date Issued: 2020
Now that we have the land: analysing the experiences of land reform beneficiaries in the Makana Municipal District of the Eastern Cape, South Africa
- Authors: Msuthu, Simela Thuleka
- Date: 2020
- Subjects: Land reform , Sustainable development , Land reform -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land settlement -- Government policy -- South Africa -- Eastern Cape , Restitution -- South Africa -- Eastern Cape , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/167551 , vital:41491
- Description: The “land question” in South Africa goes back more than a century to the 1913 Natives Land Act which facilitated the dispossession of African people from fertile land to arid homelands and congested townships. This mass dispossession of Africans from their land was accompanied by an array of legislation aimed at restricting their upward mobility, thus laying the foundations of structural inequality in South Africa. The advent of democracy in 1994 brought about a number of legislative reforms aimed at addressing the injustices that were imposed by the colonial and apartheid governments on the African people. At the forefront of these legislative efforts was the restoration of land to the original inhabitants of the country. Research indicates that, since 1994, the South African government has issued out land to different individuals and communities around the country in an attempt to address structural unemployment and poverty that plague the country. Using the Sustainable Livelihoods Theoretical framework, this study sought to examine the experiences of land reform beneficiaries in the Makana Municipal district of the Eastern Cape, in order to determine the extent to which the transfer of land to landless people has met the governments’ agenda to alleviate poverty and unemployment in the rural regions of South Africa. The findings in this study show that, successful land reform in South Africa is hindered mostly by two factors. Firstly, the inability of land beneficiaries to access quality education, skills training, finances and formal agricultural value chains. Secondly, land beneficiaries are further placed at a disadvantage by the poor quality of public services in their local municipalities and inconsistent post-settlement support from the state. The conclusion made in this study, is that the government has to be cognizant of the aforementioned structural barriers, when designing and rolling out land reform projects throughout the country. Failure to address these glaring structural barriers, will result in the creation of a peasant class of people living on underutilized land.
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- Date Issued: 2020
An analysis of the use of DNS for malicious payload distribution
- Authors: Dube, Ishmael
- Date: 2019
- Subjects: Internet domain names , Computer networks -- Security measures , Computer security , Computer network protocols , Data protection
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97531 , vital:31447
- Description: The Domain Name System (DNS) protocol is a fundamental part of Internet activities that can be abused by cybercriminals to conduct malicious activities. Previous research has shown that cybercriminals use different methods, including the DNS protocol, to distribute malicious content, remain hidden and avoid detection from various technologies that are put in place to detect anomalies. This allows botnets and certain malware families to establish covert communication channels that can be used to send or receive data and also distribute malicious payloads using the DNS queries and responses. Cybercriminals use the DNS to breach highly protected networks, distribute malicious content, and exfiltrate sensitive information without being detected by security controls put in place by embedding certain strings in DNS packets. This research undertaking broadens this research field and fills in the existing research gap by extending the analysis of DNS being used as a payload distribution channel to detection of domains that are used to distribute different malicious payloads. This research undertaking analysed the use of the DNS in detecting domains and channels that are used for distributing malicious payloads. Passive DNS data which replicate DNS queries on name servers to detect anomalies in DNS queries was evaluated and analysed in order to detect malicious payloads. The research characterises the malicious payload distribution channels by analysing passive DNS traffic and modelling the DNS query and response patterns. The research found that it is possible to detect malicious payload distribution channels through the analysis of DNS TXT resource records.
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- Date Issued: 2019
Deconstructing “the South African jazz feel”: roots, rhythms and features of South African jazz
- Authors: Thorpe, Christopher John
- Date: 2019
- Subjects: Jazz -- History and criticism , Jazz -- African influences , Jazz -- Africa --History and criticism , Jazz -- South Africa --History and criticism
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: http://hdl.handle.net/10962/76649 , vital:30612
- Description: South African jazz has established itself as a distinct and influential genre in modern popular music that merges musical elements from traditional South African musics with influences from U.S.-American jazz. Formed during a time of extreme social inequality in a divided country, South African jazz became the soundtrack of the struggle against social injustice and racial oppression, and was brought to international attention by artists such as Hugh Masekela, Miriam Makeba, and Abdullah Ibrahim who gave poignant musical expression to the hardships of the time. South African jazz is celebrated for its unique sound, original catalogue and all-important “feel”. To many listeners, performers and musicologists, it is this concept of feel that makes South African jazz so distinctive and inimitable. To date, however, much of the scholarly and popular literature on South African jazz has centred on the historical, social and political aspects of the music, with less attention given to close musical-textual analysis. A few studies have considered the melodic and harmonic language of iconic saxophonists and bass players but there are – to date – no close studies of rhythm and feel in South African jazz. Beginning to address this gap in the literature, this study uncovers some of the elements that constitute the South African jazz feel through close rhythmic and more general musical analyses of a selection of South African jazz recordings.
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- Date Issued: 2019
The design of a passenger transport interchange terminal in East London, South Africa
- Authors: Mbulawa, Mpumzi
- Date: 2018
- Subjects: Transportation buildings -- South Africa -- East London -- Designs and plans , Terminals (Transportation) -- South Africa -- East London -- Designs and plans Commuting -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/18255 , vital:28610
- Description: The purpose of this document is to look into the concept of Transport Orientated Development through the design of a Passenger Transit Intermodal in East London in the Eastern Cape, South Africa. This concept of urban design and development is one which the focus of mixed use development is centered on maximizing access to public transportation. This paper also looks into the discourse around public transportation as an important tool in the integration of cities in post-apartheid South Africa. The aim of this paper is to engage with the architectural challenges of designing an intermodal transportation hub. This paper also aims and engaging the issue of public transportation in a democratic South Africa and its integration in all its forms, which previously may have served only particular demographics of the country i.e. the mini-bus taxi as a solution to the problem of transportation in the townships and its infiltration into the city environment. Through literature, scientific and peer reviewed journals, desktop research, photographs, informal interviews such as analysis, precedence and other qualitative studies, it will be demonstrated, through interpretation of the that there is a need for the integration of public transportation and this can be best achieved through the design of an intermodal passenger transport facility. The finding of this paper is that there is a need to integrate the public transportation sectors in South Africa. The taxi industry, for example, has developed independently of the other means of public transportation i.e. the train and bus systems; and has led to a public transport system that often duplicates or triplicates its functions. In conclusion, public transportation, i.e. trains, buses and minibus axis provide an essential service to the public, especially low income groups as they service a greater portion of this population, offering several benefits such as accessibility ,cost, reduced travel time, etc. Through the design of a transit intermodal, the integration of all forms of public transportation will be shown as being an essential cornerstone to the development of more integrated South African cities in a democratic dispensation.
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- Date Issued: 2018
An investigation into the causes of disparities in literacy readiness of learners: perceptions of pre-primary teachers
- Authors: Haingura, Hildefonsia
- Date: 2017
- Subjects: Early childhood education -- South Africa , Language arts (Early childhood) -- South Africa , Literacy -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/7854 , vital:21311
- Description: This study investigated pre-primary teachers’ perceptions of the causes of disparities in the literacy readiness of pre-primary learners. The aim was to understand the reasons that teachers ascribe to differences in literacy readiness; ways in which teachers’ understanding of the causes may relate to their practices and to learners’ literacy readiness levels. The study drew from Bernstein’s pedagogic discourse as the theoretical framing and analytical tool for engaging with the data. The participants in the study were three pre-primary teachers practising in a variety of schooling contexts. In a quest for a deeper understanding of the causes, data for the study was generated using multiple sources. Structured interviews were employed to get the teachers perceptions, while classroom observations were aimed at discovering ways in which the teachers’ points of view related to their practices in the actual classroom. An analysis of documentary evidence was carried out to understand ways in which teachers’ practices adhered to the curriculum intentions, as well as ways in which their plans and curriculum documents supported the development of the emerging literacy skills of the learners. Findings of this study indicated that teachers attributed disparities in the literacy readiness of learners to factors external to the classroom and it was found that their pedagogic practices, as a result of these perceptions, were not supportive to the development of literacy skills that are pivotal for transitioning to Grade 1. The study has implications for curriculum reform, sensitization of stakeholders and teacher training in order to ensure a solid and promising academic foundation, and consequently, a successful academic future for all pre-primary learners.
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- Date Issued: 2017
The medical profession and the universalisation of South African Health Care: analysing the response of Eastern Cape general practitioners to the National Health Insurance proposals
- Authors: Hannah, Bridget
- Date: 2017
- Subjects: Health insurance -- South Africa , Health insurance -- Government policy -- South Africa , Medical care, Cost of -- South Africa , National health insurance -- South Africa , Medical policy -- South Africa , Physicians -- South Africa -- Attitudes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/6075 , vital:21029
- Description: In 2011, the Green Paper on National Health Insurance (NHI) in South Africa was released, committing the South African government to a 14-year plan to radically transform the currently inequitable health system towards providing comprehensive quality health care free at point of access to all citizens. The pursuit of universal health coverage (UHC) in South Africa forms part of a global aspiration to achieve more equitable healthcare delivery. One of the critical issues emerging from the Green Paper was how the NHI would be staffed. The NHI is unlikely to be adequately staffed without GPs but evidence suggests that private sector doctors have always been resistant to nationalisation or socialisation as a threat to their occupational power and professional status. The core work of this thesis is a study undertaken of 78 doctors in the Eastern Cape, focusing on private sector general practitioners (GPs), as the largest constituency of medical professionals in the country. The interview schedule was designed to gauge doctors' responses to the NHI, encourage discussion on their reactions to the reforms, and its implications in their view for private medical practice. The responses of the doctors are analysed through application of two theoretical themes, namely: (i) actor-centred policy creation, discussed through application of Walt and Gilson's (1994) shared focus on content, context, process and actors in the policy process, and (ii) the debate on medical professionalism, espoused by Freidson (1973, 1994) and argued against by Haug and Sussman (1969), and McKinlay (1972, 1993). Thus, if the process of policy making must take into account key actors in order to deliver a successful policy transition, what are the implications if these actors are actively excluded, or do not willingly cooperate? Does this indicate anything telling about the private sector's role to play in the pursuit of universal healthcare?
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- Date Issued: 2017
Land reform in South Africa: effects on land prices and productivity
- Authors: Van Rooyen, Jonathan
- Date: 2009
- Subjects: Right of property -- South Africa , Land reform -- South Africa , Agriculture and state -- South Africa , Agricultural prices -- South Africa , Land tenure -- Government policy -- South Africa , Land reform -- Economic aspects -- South Africa , Real property -- Prices -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:987 , http://hdl.handle.net/10962/d1002721
- Description: South Africa’s land redistribution policy (1994-2008) has been widely publicised, and has come under scrutiny of late from the public, private and government spheres, highlighting a need for research in this area. The research examines progress in South Africa’s land redistribution programme in two of KwaZulu-Natal’s district municipalities, Uthungulu and iLembe. Specifically the research investigates whether the government has paid above market prices when purchasing sugarcane farmland for redistribution in these districts. Moreover, it is illustrated how productivity on redistributed farms has been affected with the changes in ownership. To investigate the research questions, reviews of theories pertaining to property rights, land reform and market structures were conducted. Moreover, two cases studies were conducted in the districts of Uthungulu and iLembe, with assistance from the Department of Land Affairs, Inkezo Land Company and the South African Cane Growers Association. The case study data indicate that above ordinary market prices have been paid (2004-2006) by the government for sugarcane farmland in the districts concerned, and further that productivity has been negatively impacted ‘during’ and ‘post‘ transfer, in the majority of cases.
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- Date Issued: 2009
Metalorganic vapour phase epitaxial growth and characterisation of Sb-based semiconductors
- Authors: Vankova, Viera
- Date: 2005
- Subjects: Compound semiconductors , Epitaxy , Organometallic compounds , Metal organic chemical vapor deposition
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10548 , http://hdl.handle.net/10948/d1019678
- Description: This study focuses on the growth and characterization of epitaxial InAs and InAs1-xSbx. Layers are grown on InAs, GaAs and GaSb substrates by metalorganic vapour phase epitaxy, using trimethylindium, trimethylantimony and arsine as precursors. The growth parameters (V/III ratio, Sb vapour phase compositions) are varied in the temperature range from 500 ºC to 700 ºC, in order to study the influence of these parameters on the structural, optical and electrical properties of the materials. The layers were assessed by X-ray diffraction, electron and optical microscopy, photoluminescence and Hall measurements. Furthermore, the influence of hydrogenation and annealing on the electrical and optical properties of GaSb was investigated. It is shown that the growth temperature and the V/III ratio play a vital role in the resulting surface morphology of homoepitaxial and heteroepitaxial InAs layers. Growth at low temperatures is found to promote three-dimensional growth in both cases, with improvements in the surface morphologies observed for higher growth temperatures. All the investigated epilayers are n-type. It is shown that the electrical properties of heteroepitaxial InAs epilayers are complicated by a competition between bulk conduction and conduction due to a surface accumulation and an interface layer. The low temperature photoluminescence spectra of homoepitaxial InAs are dominated by two transitions. These are identified as band-to-band/excitonic and donor-acceptor recombination. The incorporation efficiency of antimony (Sb) into InAs1-xSbx is dependent on the growth temperature and the V/III ratio. Under the growth conditions used in this study, the incorporation efficiency of Sb is controlled by the thermal stability of the two constituent binaries (i.e. InAs and InSb). Changes in the low temperature photoluminescence spectra are detected with increasing x. From temperature and laser power dependent measurements, the highest energy line is attributed to band-to-band/excitonic recombination, while the peak appearing approximately 15 meV below this line is assigned to donor-acceptor recombination. The origin of an additional “moving” peak observed for higher Sb mole fraction x is tentatively attributed to quasi-donor-acceptor-recombination, arising from increased impurity/defect concentrations and a higher compensation ratio in the material. However, the unusual behaviour of this peak may also be ascribed to the presence of some degree of ordering in InAsSb. The exposure of a semiconductor to a hydrogen plasma usually leads to the passivation of shallow and deep centres, thereby removing their electrical and optical activity. In this study, the passivation and thermal stability of the native acceptor in p-type GaSb is also investigated. It is shown that this acceptor can be passivated, where after improvements in the electrical and optical properties of GaSb are observed. Upon annealing the passivated samples above 300 °C, the acceptor is reactivated.
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- Date Issued: 2005
The effect of a water-based programme on the motor proficiency of children with developmental coordination disorder (DCD)
- Authors: Joubert, Christine
- Date: 2004
- Subjects: Hydrotherapy for children -- South Africa , Motor ability in children -- South Africa -- Testing , Children with disabilities -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11032 , http://hdl.handle.net/10948/397 , Hydrotherapy for children -- South Africa , Motor ability in children -- South Africa -- Testing , Children with disabilities -- South Africa
- Description: This study determined the effect of a water-based programme on the motor proficiency of children with Development Coordination Disorder (DCD). The water-based programme promoted an alternative environment for DCD children, involving all dimensions of movement. Thirty-one (31) children from Port Elizabeth participated, with an experimental group (n=15) following the eight-week water-based programme, while a control group (n=16) carried on with daily activities. Motor proficiency was measured during three tests, utilizing the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP). Results indicated positive effects of the intervention on all the variables of the BOTMP (p < 0.05). Confirming this, three variables obtained practical significance with Cohen’s d > 0.8, and one with 0.2 < d < 0.8. At the end of the three-month duration of the study, the experimental group indicated better performances at the end of the study than at the start, thereby confirming the positive and lasting effect of the water-based intervention programme. Therefore, the use of a water-based programme in improving motor proficiency is supported. However, implementation of the programme over a longer period is recommended.
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- Date Issued: 2004
The performance of children with autism on the Revised Extended Griffiths Scales of Mental Development
- Authors: Gowar, Rosemary Vera
- Date: 2004
- Subjects: Psychological tests for children -- South Africa , Autism in children -- South Africa , Children -- Intelligence testing -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11016 , http://hdl.handle.net/10948/353 , Psychological tests for children -- South Africa , Autism in children -- South Africa , Children -- Intelligence testing -- South Africa
- Description: Despite a widespread perception that the number of children coming to clinical attention with Autism Spectrum Disorders has greatly increased, limited South African Research has been conducted on children with Autism. Thus a need exists to accumulate knowledge about the cognitive, psychological and personalsocial growth of children diagnosed with Autism. This study is aimed at exploring the performance of children with Autism between the ages of 7 years (from 72 months) and 8 years (to 95.9 months), in South Africa (SA), utilising the Revised Extended Griffiths Scales of Mental Development (GSMD). The sample comprised an experimental group of 30 children with Autism from four schools for Specialised Education for learners with Autism in SA, and a control group comprised of 30 “normal” children, where normalcy can be broadly defined as “an absence of any sensory, physical or mental handicap”. The six areas of general development assessed included Locomotor, Personal- Social, Language, Eye and Hand co-ordination, Performance, and Practical Reasoning. A non-probability, purposive sampling method was applied. The major findings of the present study were as follows: (i) Children with Autism (years 7 & 8) showed a characteristic cognitive profile when tested with the revised Extended Griffiths Scales. Their performance indicates lower performance on Subcales B, C and F than on the other Subscales. (ii) Some children with Autism experienced major fall-outs, whereas others were slightly below average. The general performance of children with Autism was, however, in the range “cognitively impaired”. (iii) There was significant difference between the Autistic sample and the normal sample on the GQ. xiv In view of the findings, it is recommended that the results of the study, which focused on the children’s areas of developmental weakness, be widely disseminated. This could facilitate the development of therapeutic programmes, so as to allow for appropriate stimulation for children with Autism.
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- Date Issued: 2004
Sensorless speed estimation in three phase induction motors
- Authors: Govindsamy, Matthew
- Date: 2002
- Subjects: Electric motors, induction , Electronic controllers
- Language: English
- Type: Thesis , Masters , MTech (Electrical Engineering)
- Identifier: vital:10810 , http://hdl.handle.net/10948/139 , Electric motors, induction , Electronic controllers
- Description: This thesis proposes a technique to determine and improve the performance of a sensorless speed estimator for an induction motor based on Motor Current Signature Analysis (MCSA). The theoretical concepts underlying the parameter based observer are developed first and then the model of the observer is built using Simulink. The observer is developed based on Model Reference Adaptive System (MRAS). The dynamic performance of the observer and its behavior due to variation of machine parameters is studied. The error in speed estimated using this observer is shown and the ability of MCSA to retune the rotor speed from the stator current spectrum. The spectrum estimation technique has been implemented using a software routine in Matlab. Both the observer and MCSA techniques were implemented practically on an induction motor. The performance of the combined sensorless speed estimation system was tested and verified.
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- Date Issued: 2002
Therapists' constructs of healthy functioning as aspirational goal in transformative psychotherapy
- Authors: Steyn, Reinette
- Date: 2000
- Subjects: Psychotherapy , Mental health -- South Africa , Mental health
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3064 , http://hdl.handle.net/10962/d1002573 , Psychotherapy , Mental health -- South Africa , Mental health
- Description: This dissertation reviews the ways in which psychotherapists working in relatively long-term 'transformational' therapies construct the outcome goals of their interventions. It is generally accepted that a therapist's beliefs about what constitutes mental health will influence the client, and will therefore facilitate a certain outcome accordingly. A problem in a long-term, 'non-directive' therapy is that the eventual outcome is not always visible in the interim development of the client or in the business of individual sessions. Without a clearly defined 'plan' or 'goal' there is a real danger of the intervention having opposite results to what would have been desirable, or no noticeably beneficial results, both of which can be an abuse of the client's investment and trust in the process. The absence of clearly constructed goals makes it difficult to assess efficacy of a therapeutic method used to attain an improved state of mental health that will be lasting, i.e. a positive 'transformation'; it also problematises comparisons across orientations. The identification of explicit goals is of special importance in a developing 'third-world' community like South Africa, where western ('European') concepts of mental health are being offered as an alternative to so-called 'indigenous healing' and where different cultural communities may have different expectations, needs or demands of their members 'in health'. Individual-based therapeutic orientations included in the research were psychoanalysis and psychoanalytic therapies, including object-relational therapies with various emphases and self psychology, as well as transformative types of hypnosis, Gestalt therapy, client-centred therapy and transactional analysis. Twenty of the semi-structured interviews with 52 therapists working in one or more of these areas were selected for construct analysis. Through analysis of the constructs of mental health as aspirational goal that emerged in therapists' talking about their experience of the process and the consequences of therapy observed in their patients, it appeared that there are generalisable constructs across various orientations in the transformative therapies. It is hoped that these constructs may serve as a foundation for further research in the problem areas indicated, but also that therapists working in the field may use this research not only as a basis for self-evaluation, but for adding to the constructs from their own experience, to the further enrichment of the whole field of work.
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- Date Issued: 2000