Network-layer reservation TDM for ad-hoc 802.11 networks
- Authors: Duff, Kevin Craig
- Date: 2008
- Subjects: Computer networks -- Access control , Computers -- Access control , Computer networks -- Management , Time division multiple access , Ad hoc networks (Computer networks)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4574 , http://hdl.handle.net/10962/d1002773 , Computer networks -- Access control , Computers -- Access control , Computer networks -- Management , Time division multiple access , Ad hoc networks (Computer networks)
- Description: Ad-Hoc mesh networks offer great promise. Low-cost ad-hoc mesh networks can be built using popular IEEE 802.11 equipment, but such networks are unable to guarantee each node a fair share of bandwidth. Furthermore, hidden node problems cause collisions which can cripple the throughput of a network. This research proposes a novel mechanism which is able to overcome hidden node problems and provide fair bandwidth sharing among nodes on ad-hoc 802.11 networks, and can be implemented on existing network devices. The scheme uses TDM (time division multiplexing) with slot reservation. A distributed beacon packet latency measurement mechanism is used to achieve node synchronisation. The distributed nature of the mechanism makes it applicable to ad-hoc 802.11 networks, which can either grow or fragment dynamically.
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- Date Issued: 2008
Journalists' appropriation of ICTs in news-gathering and processing: a case study of Grocott's Mail
- Authors: Dugo, Habtamu Tesfaye
- Date: 2008
- Subjects: Grocott's Mail (Grahamstown, South Africa) Journalism -- South Africa -- Grahamstown Journalists -- South Africa -- Grahamstown Electronic news gathering -- South Africa -- Grahamstown Journalism -- Data processing -- South Africa -- Grahamstown Information technology -- South Africa -- Grahamstown Reporters and reporting -- South Africa -- Grahamstown Communication and technology -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3427 , http://hdl.handle.net/10962/d1002881
- Description: This study set out to investigate Grocott’s Mail journalists’ appropriation of information and communication technologies in news-gathering and processing using the social shaping of technology as a theoretical lens. It mainly focuses on digital ICTs that journalists use in news-gathering and processing including the Internet, electronic mail, and mobile telephony. Grocott’s Mail is a small-scale newspaper based in Grahamstown, South Africa. Using qualitative research method and the case study as its sub-method, the research reveals that Grocott’s Mail journalists’ appropriation of ICTs involves various opportunities and challenges in news-gathering and processing. In terms of the state of the existing technological infrastructure, the study reveals that since it embraced the digital ICTs in 2003, Grocott’s Mail boasts an adequate ICT infrastructure for a small-scale African newspaper with 30 PCs and one laptop, and professional software for 28 permanent employees. On the other hand, the research reveals serious constraints with the existing ICTs: a huge need for staff training and capacity building to fully utilise the ICTs, and the need to look for ways of raising funds to either upgrade or replace the existing ICTs. Grocott’s Mail journalists use the Internet to do background research on news stories, to verify the accuracy of information, and to check competition across other media. These are the merits of the Internet in news-gathering and processing. On the other hand, there are specific unintended consequences of the Internet such as wasting the company’s working time, and its use leading to lazy/press release journalism. Informants unanimously indicate that the main problems of the Internet are heavy dependence on other online news-sources and wasting time on online entertainment. In terms of using email in news-gathering, the research finds email technology as having advantages such as being a tool of flexibility and speed, a tool for email interviews, and as a technology that promotes participatory journalism. On the other hand, challenges related to email include its limitations because of what interviewees view as its supplementary and small-scale use because of its low contextual richness as opposed to face to face interviews. In terms of cellular telephony, the study finds that regardless of the ubiquity of cell phones and cell phone networks, they have not yet been deployed in news-gathering and processing due to various constraints. These are cell phones not being a big factor in reporting, lack of a proper funding and refunding scheme, prevalence of negative attitudes towards cell phones, and lack of a business model. Thus, cellular phones seem to have little or no relevance in news-gathering and processing at Grocott’s Mail presently.
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- Date Issued: 2008
A critical evaluation of section 332 of the Criminal Procedure Act 51 OF 1977
- Authors: Dunywa, Mziwonke Samson
- Date: 2008
- Subjects: Criminal procedure -- South Africa -- Evaluation , South Africa. Criminal Procedure Act, 1977
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10197 , http://hdl.handle.net/10948/748 , Criminal procedure -- South Africa -- Evaluation , South Africa. Criminal Procedure Act, 1977
- Description: The general principle in criminal law is that a person is liable when committing a criminal offence. This may include an offence a person has facilitated or procured. Vicarious liability, a principle borrowed from civil law, is an exception to the general rule in that it allows for a person to be held liable for the criminal acts of another. Legal persons have no physical existence and do not have hands and brains like natural persons. A legal person acts through its directors, employees, members or representatives. The corporation, being distinct and separate from its agents, is held liable for the acts or omissions of its representatives. This liability exists even though the corporate body never acted. International recognition of corporate criminal liability can be based on vicarious liability, identification or aggregation. All these forms of liability are derived from the human actus and mens rea. The identification theory provides for the liability of the corporate body, when someone who is identified with it, acted during the course of his employment when committing the offence. Those acts are treated as the acts of the corporate body. The identification theory is normally applied where mens rea is a requirement of the offence. The Aggregation theory provides for criminal liability of the corporation based on the conduct of a group of members of the company taken collectively. This theory is applied effectively where it is difficult to prove that a single person within the company is responsible for the commission of the offence. In South Africa corporate criminal liability developed from vicarious liability. It is regulated by section 332(1) of the Criminal Procedure Act 51 of 1977. This liability is based on the special relationship between the director or servant and the corporate body. Corporations act through its agents. The agent can be a director, servant or a third person instructed by either of them. In terms of section 332(1) it is possible that the corporate body can be held liable even where the agent acted beyond the scope of his employment. The latter can be argued is an extension of vicarious liability. Vicarious liability, can be argued, is too broad, because the intention of the agent is imputed to the corporate body, without the enquiry of fault by the corporate body. This offends the general principles of substantive criminal law. Generally, liability in criminal law accrues to someone who committed the offence with the required state of mind. The constitutionality of section 332(1) Act 51 of 1977 is questioned. The question is asked whether it is desirable to punish a legal person for the behaviour of its representatives or employees. Criminal law purports to control the behaviour of individuals to be in line with the interest and values of society. There is doubt whether the same goal can be achieved with the prosecution of corporate bodies. Prosecution of corporate bodies results in stigma to the corporation, which results in suffering a loss of reputation. Some authors argue that civil remedies can control the activities of corporate bodies more effectively. This argument, however, fails to address the issue that criminal law concerns the harm inflicted by human beings, hence the need to regulate human conduct. Corporate criminal liability attempts to address the harm inflicted by corporate bodies. It regulates pollution, health, safety and business. This liability is firmly established around the world but requires further development and modern refinement in South Africa. , Abstract
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- Date Issued: 2008
Energy transfer in zinc porphyrin–phthalocyanine heterotrimer and heterononamer studied by fluorescence resonance energy transfer (FRET)
- Authors: Durmus, Mahmut , Chen, Jiyao Y , Zhao, Zhixin X , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268599 , vital:54213 , xlink:href="https://doi.org/10.1016/j.saa.2007.07.010"
- Description: Two or eight zinc triphenyl porphyrins were conjugated with Zn-phthalocyanine or H2-phthalocyanine to form ZnPc–(ZnTPP)2, ZnPc–(ZnTPP)8, H2Pc–(ZnTPP)2 and H2Pc–(ZnTPP)8. Energy transfers from the porphyrin moiety to phthalocyanine part were quantitatively studied with the modality of fluorescence resonance energy transfer (FRET). By measuring the fluorescence increment from the phthalocyanine moiety and the decrease from porphyrin part under selective excitation at the B band of the porphyrin part in those conjugated compounds and their equimolar mixture of compositions, energy transfer efficiencies were estimated to be 90% for H2Pc–(ZnTPP)8 and ZnPc–(ZnTPP)8, and 60%, 30% for ZnPc–(ZnTPP)2 and H2Pc–(ZnTPP)2, respectively.
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- Date Issued: 2008
Photophysicochemical and Fluorescence quenching studies of benzyloxyphenoxy substituted zinc phthalocyanines
- Authors: Durmuş, Mahmut , Nyokong, Tebello
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6570 , http://hdl.handle.net/10962/d1004133
- Description: Photochemical and photophysical measurements were conducted on peripheral and non-peripheral tetrakis- and octakis(4-benzyloxyphenoxy)-substituted zinc phthalocyanines (1, 2 and 3). General trends are described for photodegradation, and fluorescence quantum yields, triplet lifetimes and triplet quantum yields as well as singlet oxygen quantum yields of these compounds in dimethylsulphoxide (DMSO) and toluene. The fluorescence of the complexes is quenched by benzoquinone (BQ), and fluorescence quenching properties are investigated in DMSO and toluene. The effects of the solvents on the photophysical and photochemical parameters of the zinc(II) phthalocyanines (1, 2 and 3) are also reported. Photophysical and photochemical properties of phthalocyanine complexes are very useful for PDT applications.
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- Date Issued: 2008
Adoption of business information systems in an automotive manufacturing environment: a case study
- Authors: Dyer, Shirley
- Date: 2008
- Subjects: Management information systems , Technology -- Information services , Information resources management , Business -- Data processing
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9772 , http://hdl.handle.net/10948/892 , Management information systems , Technology -- Information services , Information resources management , Business -- Data processing
- Description: Dorbyl Automotive Technologies (DAT) is a manufacturing company that supplies parts and components to the local and international motor vehicle market. The automotive components’ market is very competitive and customers require more from the industry to stay competitive. Customers require full integration throughout the supply chain. DAT and its Information Systems Department have ensured that the necessary business information systems are available to assist the company in staying competitive. One problem, though, is that the users of these systems are not using and adopting the technologies available. This research examines the reasons for this by making use of a technology acceptance model called the UNIFIED THEORY OF ACCEPTANCE AND USE OF TECHNOLOGY (UTAUT), which is an integrated model based on eight different available acceptance models. The aim is to understand which factors influence the use of systems. The research also proposes a way forward by suggesting a model to assist DAT in new system implementations as well as correcting the current situation. The only way DAT will stay competitive is by ensuring that the company becomes lean. Customers demand this as more and more are moving to just-in-time delivery. This implies that the suppliers must react to changes real-time. The use of business information systems will become the main focus area to react to changes quickly and correctly. Effective and accurate systems depend on users making good use of these systems. Remaining competitive will depend on how effectively Information and Communication Technologies (ICT) are used.
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- Date Issued: 2008
Community participation and project sustainability in rural Zimbabwe: the case of Sangwe communal lands
- Authors: Dzinavatonga, Naison
- Date: 2008
- Subjects: Rural development -- Zimbabwe -- Case studies , Local government -- Zimbabwe -- Case studies , Municipal services -- Zimbabwe -- Case studies , Community development -- Zimbabwe
- Language: English
- Type: Thesis , Masters , M Soc Sc (Dev)
- Identifier: vital:11408 , http://hdl.handle.net/10353/130 , Rural development -- Zimbabwe -- Case studies , Local government -- Zimbabwe -- Case studies , Municipal services -- Zimbabwe -- Case studies , Community development -- Zimbabwe
- Description: Development thinkers and practitioners have been pondering over community participation for the last decades. Some even called the 1980s a decade of participation in development discourse while others also view the current decade of social movements, Non-Governmental Organizations, and Community-Based Organizations as a manifestation of organized community participation. The Sangwe Communal Lands is one such area that researchers in the last decades have been pondering over the role of community participation in project sustainability. Likewise this study evaluates the effectiveness of community participation in Sangwe where it has been hypothesized that the current participation discourse has not lived up to its billing of ensuring sustainable projects. The research therefore explores some of the politics surrounding community participation in Sangwe and Zimbabwe at large. From one angle to the other, the research overviews some of the different theoretical orientations, goals, processes and practices that are commonly used but not always recognized to constitute genuine community participation. The research is intended to clarify some of the differences that emerge when projects are designed, and to stimulate discussion about community participation more generally. This study shows that the local communities who in this case are the reason for being of NGOs and their programmes are quite critical in development projects undertaken in their own areas. This to a larger extent determines the success of development initiatives at all levels. Such a scenario calls for a proper sustainable and pro-rural community legal and policy framework as a pre-requisite for sustainable projects. The study further highlights the need for development workers and agents to change their attitude towards communities and their indigenous knowledge systems. They need to co-opt community indigenous knowledge as a system that has a unique contribution to sustainable development. Above all, attitude change is the pillar for the New World System and 21st century development paradigm that respects local values, concerns, culture, and aspirations and that these should be taken on board in the management of development programmes.
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- Date Issued: 2008
Handling multiple levels of data and multiple research questions in an embedded case study : methodological challenges
- Authors: Edwards, David J A
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6247 , http://hdl.handle.net/10962/d1007865
- Description: Hougaard et al. report an embedded case study in which nine socially phobic clients were treated as part of a therapy program, which incorporated individual and group therapy and which was largely delivered by trainee clinicians. An important focus of the report is on the effectiveness of their treatment model. This commentary draws attention to the size and complexity of the available data, and it suggests ways in which the use of a more explicitly interpretative methodology can draw out additional dimensions of the data and allow a more systematic contribution to be made to the development of clinical theory.
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- Date Issued: 2008
The solvent-free approach versus the use of ionic liquids in the synthesis of ferrocenes
- Authors: Elago, Elago R T
- Date: 2008
- Subjects: Ferrocene , Inorganic compounds -- Synthesis , Ionic solutions , Solvents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10396 , http://hdl.handle.net/10948/853 , Ferrocene , Inorganic compounds -- Synthesis , Ionic solutions , Solvents
- Description: The philosophy of green chemistry has seen much development in the past decade. The use of environmentally benign solvents is amongst the areas of green chemistry that have received the most attention. In this context, imidazolium ionic liquids have been widely reported to offer high product yields, fast reaction rates, excellent selectivity and generally mild working conditions, when used as reaction media. In addition, concerns about costs of solvents and the long-term environmental impact that can potentially result when solvents are discarded after their use have led to focused investigations into solvent-free procedures, as reported in recent literature. We have set out to explore the extent to which these advantages could be realized within our research. Non-volatile, non-flammable imidazolium ionic liquids [bmim][I], [bmim][BF4] and [bmim][PF6] were used as green solvents in ferrocene chemistry. Ferrocenoate esters were synthesised efficiently by the respective DCC/DMAP-promoted reactions of ferrocenecarboxylic acid and substituted benzoic acids or, alternatively, the DMAP-promoted reactions of ferrocenoyl fluoride with a range of substituted phenols in [bmim][BF4] and [bmim][PF6]. High yields and short reaction times were achieved. In addition, the ionic liquid was reused several times without a reduction in product yields. Under solvent-free conditions, DCC/DMAP-promoted reactions provided high yields within 3 min of reaction. The possible rearrangement of one of the intermediates in these reactions was modelled theoretically using density function theory (DFT) at the B3LYP/6-31G* level of approximation. Catalyst-free esterification was achieved by the application of microwave radiation to the reaction of ferrocenoyl fluoride and a range of substituted phenols. All the reactions were complete after 1 min of irradiation and products were isolated in high yield. DPAT, HfCl4, Sc(OTf)3 and Al(OTf)3 were screened as catalysts for esterification in [bmim][BF4] and under solvent-free conditions at various temperatures. All attempts at esterification of ferrocenecarboxylic acid with alcohols and phenols were unsuccessful. The Suzuki cross-coupling reaction was carried out in [bmim][BF4]. The isolated yields are, however, poor and suffer from poor reproducibility with different batches of [bmim][BF4] used.
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- Date Issued: 2008
Environmental health work methods and procedures for the surveillance and control of avian influenza in the Eastern Cape Province, South Africa
- Authors: Elie, Sammy Abraham
- Date: 2008
- Subjects: Avian influenza -- Eastern Cape -- South Africa -- Prevention , Environmental health -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9834 , http://hdl.handle.net/10948/947 , http://hdl.handle.net/10948/d1009648 , Avian influenza -- Eastern Cape -- South Africa -- Prevention , Environmental health -- South Africa -- Eastern Cape
- Description: Avian influenza is an infectious disease of birds caused by the Type A strain of the influenza virus. The disease, which was first identified in Italy more than 100 years ago, occurs worldwide (World Health Organization, 2006a). The current outbreak of the highly pathogenic avian influenza A (H5N1), which began in Southeast Asia in mid-2003, is the largest and most severe on record. Never before in the recorded history of this disease have so many countries been simultaneously affected. Since the last pandemic in 1968-1969, the risk of an influenza pandemic has not been considered greater than at the present time. The importance of intervention strategies had become increasingly evident throughout the world. The World Health Organization provides a generic outline for preparedness plans to assist countries in their preparations to respond to a possible avian influenza pandemic. These guidelines may be modified as the epidemiology of avian influenza evolves. The South African National Department of Health has developed national guidelines in the form of an avian influenza preparedness plan. These draft guidelines do not provide detailed Environmental Health work methods and - procedures for the effective surveillance and control of the disease. The general purpose of this study is to develop a standardised set of Environmental Health work methods and - procedures, which will contribute to the effective surveillance and control of avian influenza in the Eastern Cape province – South Africa. Within the context of the purpose of this study, a qualitative, explorative, descriptive, inductive and deductive research design will be used. The methods of data collection will be documentary research, telephonic as well as in-depth personal interviews. In this study, documentary research will be the primary method of data collection. With a qualitative approach, the researcher will be the human instrument for data analysis. The process of qualitative data analysis will be based on data reduction and interpretation; and will be conducted as an activity simultaneously with data collection, data interpretation and narrative reporting writing.
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- Date Issued: 2008
Juvenile population dynamics of Oreochromis mossambicus in an intermittently open estuary at the limit of its natural distribution
- Authors: Ellender, Bruce R , Weyl, Olaf L F , Shanyengange, M K , Cowley, Paul D
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446893 , vital:74568 , https://doi.org/10.1080/15627020.2008.11657245
- Description: Juvenile Oreochromis mossambicus in the 25 ha, temperate, intermittently open, East Kleinemonde Estuary in the Eastern Cape, South Africa (33°32’S, 27°03’E), showed a seasonal shift in distribution, occupying all areas of the estuary in summer and, subsequently, being limited to the upper reaches in winter. The young of the year in the littoral zone were rapidly depleted and resultant estimates of the instantaneous rate of total mortality (Z) ranged from 5.4/yr to 6.9/yr. High annual rates of juvenile mortality and small adult populations imply that stock recovery after a reduction in adult population numbers, through activities such as fishing, may be slow. This work adds to the knowledge base of O. mossambicus ecology and population dynamics in temperate estuaries at the limit of its natural distribution.
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- Date Issued: 2008
An investigation into electronic-source plagiarism in a first-year essay assignment
- Authors: Ellery, Karen
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70114 , vital:29621 , https://doi.org/10.1080/02602930701772788
- Description: Since the emergence of the electronic era, plagiarism has become an increasingly prevalent problem at tertiary institutions. This study investigated the role electronic sources of information played in influencing plagiarism in an essay assignment in a first-year geography module at the University of KwaZulu-Natal in South Africa. Despite explicit instruction in tutorials on academic writing, referencing and plagiarism, a quarter of students still plagiarised in their essay, with the majority having done so off the Internet. A survey questionnaire and interviews revealed that not only did the school writing experience prepare students poorly for academic writing discourses, but also highlighted that student ignorance with regard to acknowledgement of electronic sources, a pervasive perception of difference between electronic and print sources, as well as the availability of the copy-and-paste facility which reinforces the product view of writing, all contributed towards electronic-source plagiarism. Active instructional engagement with electronic-source material, and open dialogue on ownership of knowledge as well as on moral and ethical issues with students, are recommended as strategies to overcome such plagiarism.
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- Date Issued: 2008
WET-Origins: controls on the distribution and dynamics of wetlands in South Africa
- Authors: Ellery, William F N , Grenfell, Michael C , Grenfell, Suzanne E , Kotze, Donovan C , McCarthy, Terence S , Tooth, Stephen , Grundling, Piet-Louis , Beckedahl, Heinz , Le Maitre, David C , Ramsay, Lisa F
- Date: 2008
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/176598 , vital:40091 , ISBN 978-77005-633-6 , https://www.wrc.org.za/mdocs-posts/wetland-management-series-wet-origins-controls-on-the-distribution-and-dynamics-of-wetlands-in-south-africa/
- Description: The need for wetland rehabilitation in South Africa is compelling: loss and degradation of wetlands have been great and national policy and legislation provide clear direction and support for rehabilitation. However, rehabilitating wetlands is often complex because wetlands and their links with people are complex (e.g. through the ways that people use wetlands and the different benefits that people receive from the ecosystem services that wetlands supply).
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- Date Issued: 2008
Risk assessment and the effects of overhead work - an automotive industry example
- Authors: Elliott, Andrew Brent
- Date: 2008
- Subjects: Human engineering -- South Africa , Industrial safety -- South Africa , Automobile industry workers -- South Africa -- Health risk assessment , Automobile industry and trade -- South Africa -- Safety measures , Musculoskeletal system -- Wounds and injuries -- Prevention , Lifting and carrying -- Safety measures , Work measurement , Posture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5132 , http://hdl.handle.net/10962/d1005211 , Human engineering -- South Africa , Industrial safety -- South Africa , Automobile industry workers -- South Africa -- Health risk assessment , Automobile industry and trade -- South Africa -- Safety measures , Musculoskeletal system -- Wounds and injuries -- Prevention , Lifting and carrying -- Safety measures , Work measurement , Posture
- Description: The focus of this investigation was an analysis of the work demands being placed on South African automotive industry workers as there is a recognised problem with regard to the prevalence of musculoskeletal disorders (MSDs). Preliminary work was conducted to highlight the dominant risks and areas which elicited higher numbers of MSDs within the chosen automotive plant. An area of concern was highlighted through medical record analysis and the use of risk assessment tools, thereby prioritising the need for ergonomic intervention. In particular, the effects of varying restricted and overhead work heights on the biomechanical, physiological and psychophysical responses of an individual were investigated. Twenty-eight subjects were required to complete sixteen conditions. The conditions consisted of the adoption of restricted and upright overhead static postures, with half requiring the holding of four kilograms of weight in the hands and the remaining eight conditions having no weight. Testing was carried out using an electromyography unit, ergospirometer and a perceptual Body Discomfort Map and Scale. This involved a habituation and testing session. The results of the testing revealed the biomechanical and physiological responses were dependant on the change in height. Body discomfort was also shown to be variable over the changing height conditions. This indicates that there is a significant effect of height on an individual’s responses during overhead work. The extreme restricted (-200mm and -100mm) and upright (+300mm and +400mm) overhead conditions within this study were limiting, as they elicited the highest muscle activation, physiological responses and body discomfort ratings. Positions that are preferable to adopt, which were identified from the results in this study, indicate conditions closer to head height (0mm and +100mm) were favourable. The results therefore illustrate how awkward working postures during work are likely to elicit higher demands from an individual, which could lead to an increased risk for the development of a musculoskeletal disorder. The added factor of weight elicited significant results over all variables, excluding a respiratory The focus of this investigation was an analysis of the work demands being placed on South African automotive industry workers as there is a recognised problem with regard to the prevalence of musculoskeletal disorders (MSDs). Preliminary work was conducted to highlight the dominant risks and areas which elicited higher numbers of MSDs within the chosen automotive plant. An area of concern was highlighted through medical record analysis and the use of risk assessment tools, thereby prioritising the need for ergonomic intervention. In particular, the effects of varying restricted and overhead work heights on the biomechanical, physiological and psychophysical responses of an individual were investigated. Twenty-eight subjects were required to complete sixteen conditions. The conditions consisted of the adoption of restricted and upright overhead static postures, with half requiring the holding of four kilograms of weight in the hands and the remaining eight conditions having no weight. Testing was carried out using an electromyography unit, ergospirometer and a perceptual Body Discomfort Map and Scale. This involved a habituation and testing session. The results of the testing revealed the biomechanical and physiological responses were dependant on the change in height. Body discomfort was also shown to be variable over the changing height conditions. This indicates that there is a significant effect of height on an individual’s responses during overhead work. The extreme restricted (-200mm and -100mm) and upright (+300mm and +400mm) overhead conditions within this study were limiting, as they elicited the highest muscle activation, physiological responses and body discomfort ratings. Positions that are preferable to adopt, which were identified from the results in this study, indicate conditions closer to head height (0mm and +100mm) were favourable. The results therefore illustrate how awkward working postures during work are likely to elicit higher demands from an individual, which could lead to an increased risk for the development of a musculoskeletal disorder. The added factor of weight elicited significant results over all variables, excluding a respiratory individual.
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- Date Issued: 2008
Conceptualisations of 'the community' and 'community knowledge' among community radio volunteers in Katutura, Namibia
- Authors: Ellis, Hugh
- Date: 2008
- Subjects: Katutura Community Radio Community radio -- Namibia Radio broadcasting -- Namibia Radio stations -- Namibia Radio journalism -- Namibia Volunteers -- Namibia Radio in community development -- Namibia Mass media -- Social aspects -- Namibia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3428 , http://hdl.handle.net/10962/d1002882
- Description: Community radio typically relies on volunteers to produce and present stations’ programming. Volunteers are generally drawn from stations’ target communities and are seen as “representatives” of those communities. It is with such volunteers and their role as representatives of stations’ target communities that this study is concerned. It poses the question: “what are the central concepts that typically inform volunteers’ knowledge of their target community, and how do these concepts impact on their perception of how they have gained this knowledge, and how they justify their role as representatives of this community?” The dissertation teases out the implications of these conceptualisations for a volunteer team’s ability to contribute to the establishment of a media environment that operates as a Habermasian ‘critical public sphere’. It argues that this can only be achieved if volunteers have detailed and in-depth knowledge of their target community. In order to acquire this knowledge, volunteers should make use of systematic ways of learning about the community, rather than relying solely on knowledge obtained by living there. In a case study of Katutura Community Radio (KCR), one of the bestknown community radio stations in Namibia, the study identifies key differences in the way in which different groups of volunteers conceptualise “the community”. The study focuses, in particular, on such difference as it applies to those who are volunteers in their personal capacity and those who represent non-governmental and community-based organisations at the station. It is argued that two strategies would lead to significant improvement in such a station’s ability to serve as a public sphere. Firstly, the station would benefit from an approach in which different sections of the volunteer team share knowledge of the target community with each other. Secondly, volunteers should undertake further systematic research into their target community. It is also argued that in order to facilitate such processes, radio stations such as KCR should recognise the inevitability of differences between different versions of “community knowledge”.
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- Date Issued: 2008
A framework for managing timetable data quality within the NMMU
- Authors: Els, Dierdre Jean
- Date: 2008
- Subjects: Computer algorithms Timetables , Management information systems , Management -- Data processing , Information storage and retrieval systems -- Management , Information management
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9769 , http://hdl.handle.net/10948/948 , Computer algorithms Timetables , Management information systems , Management -- Data processing , Information storage and retrieval systems -- Management , Information management
- Description: This dissertation investigates the influencing factors on timetable quality, not only from a data quality perspective, but also from an information quality perspective which takes into account the quality of the business processes involved in creating the timetable. The Nelson Mandela Metropolitan University was used as a case study for assessing the quality of the timetable process, the quality of the source data, and the quality of the final timetable produced. A framework for managing the data quality during the timetabling process is proposed. The framework is based on reviews done on data quality management best practices and data quality aspects. Chapter 1 introduces the current Nelson Mandela Metropolitan University timetable, and motivates why data quality management is essential to its success. The scope and research objectives are presented for this dissertation. Chapter 2 covers a literature study on business process and data quality management best practices. The common thread through all the management methodologies investigated, was top management involvement and commitment to continuously improving the quality of data. Chapter 3 discusses various characteristics of data quality. Quality is determined to be whether the end result meets the quality requirements for which it was intended. Hence each system could have quality aspects that are unique to it. Chapter 4 explains various research designs and which were followed for this dissertation. The combination of literature studies, a questionnaire and a case study were used. Chapter 5 is a case study of the data quality and timetabling processes used at the Nelson Mandela Metropolitan University and is based on the research design described in chapter 4. The current business processes followed in setting up the current timetable are presented, as well as the proposed timetabling process that should produce a better quality timetable for the Nelson Mandela Metropolitan 4 University. The data quality aspects most pertinent to the Nelson Mandela Metropolitan University are determined, being timeliness, accountability, integrity and consistency, as well as the most probable causes for bad timetable quality, like uniform technology, processes, ownership and using a common terminology. Chapter 6 presents a framework for managing timetable data quality at the Nelson Mandela Metropolitan University using an Information Product Map approach that will ensure a better quality timetable. Future research is also proposed. It is evident from this dissertation that data quality of source data as well as the quality of the business process involved is essential for producing a timetable that satisfies the requirements for which it was intended. The management framework proposed for the Nelson Mandela Metropolitan University timetabling process can potentially be used at other institutions as well.
- Full Text:
- Date Issued: 2008
Cranial ontogeny of the sole, dagetichthys marginatus (soleidae), with considerations on the feeding ability of larvae and early juveniles
- Authors: Ende, Stephan Siegfried Werner
- Date: 2008
- Subjects: Soleidae , Fishes -- Larvae -- Food , Flatfishes -- Nutrition , Artemia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5250 , http://hdl.handle.net/10962/d1005093 , Soleidae , Fishes -- Larvae -- Food , Flatfishes -- Nutrition , Artemia
- Description: The overall aim of this study was to gain a better understanding of the feeding mechanisms of the larvae and early juveniles of the sole, Dagetichthys marginatus (Soleidae), with which to assess the suitability of current feeding protocols and to facilitate the development of an appropriate pelleted feed. This was achieved by examining the ontogeny of the cranium of laboratory reared sole, with particular emphasis on those elements associated with feeding and by comparing the cranium of juvenile fish with that of adult fish. At 4 dah (days after hatch) Dagetichthys marginatus larvae develop the first rudimentary branchial arches that facilitates the capture and ingestion of food items. Subsequent development of cranial structures, such as the oral jaws, suspensorium, neurocranium, hyoid and branchial arches and the opercular apparatus enables the larvae, at 16 dah, to switch from ram feeding to suction feeding on live prey. The use of live Artemia nauplii from 4 to 16 dah is therefore appropriate. The first morphological asymmetries developed at 16 dah in the dentaries and at 22 dah the maxillae and the premaxillae began to show asymmetries. Teeth were present only on the blind side of the oral jaw elements and during this period (16 to 22 dah) the existing elements began to ossify. From 16 to 35 dah the standard feeding protocol consists of a combination of pelagic (Artemia metanauplii) and benthic prey (dead, frozen Artemia nauplii) and from 25 dah onwards a sinking pellet is provided. The time (dah) at which frozen Artemia and sinking pellets were provided, appropriately corresponded to the initiation of benthic feeding behaviour. However at this stage the use of pelagic Artemia metanauplii is inappropriate and unnecessary. At 31 dah the cranial morphology resembled that of adult fish. Adult D. marginatus display extreme asymmetries among the elements of the oral jaws, the suspensorium and certain elements of the neurocranium. Elements on the blind side are larger and more robust than those on the ocular side and are adapted for feeding, while those on the ocular side appear to have a respiratory function. From 31 dah the cranial elements are identical to those of adult fish, suggesting that no further feeding behavioural changes occurred and that a sinking pellet, of which the nutrient composition meets the requirements of the fish, would be appropriate for ongrowing.
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- Date Issued: 2008
Investigating the potential for the application of lean manufacturing in the can coating plant at Duco Coatings
- Authors: Erasmus, Deidre Felicia
- Date: 2008
- Subjects: Manufacturing processes -- South Africa , Waste minimization -- South Africa , Production management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8579 , http://hdl.handle.net/10948/949 , Manufacturing processes -- South Africa , Waste minimization -- South Africa , Production management -- South Africa
- Description: Companies are constantly expected to be more competitive while working in an environment in which time and cost are limited, thereby preventing such companies from taking the time required to be responsive. It is, therefore, important that companies understand that conventional knowledge and methods will not serve unless there is a concerted focus on improvement of organisational performance toward fulfilling increased expectations, not just maintaining that which is comfortable. A more sustainable approach may be the introduction of lean manufacturing techniques. The lean manufacturing process is one that continuously strives to eliminate waste, thereby increasing the percentage of time that may be devoted to value-adding activities. Lean manufacturing principles were applied in the Can Coating Plant of Duco Speciality Coatings. This study was intended to identify waste in the current production process in the Can Coating Plant and then to use lean tools and principles to eliminate such waste. Implementation of these lean tools proved to result in a leaner and more value-adding process. The new process rendered a positive result on Duco Coating’s costs, quality and product performance. Recommendations on further improvements were also offered.
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- Date Issued: 2008
An evaluation of the questions posed to child witnesses in court to determine whether they are developmentally appropriate
- Authors: Erasmus, Ronell
- Date: 2008
- Subjects: Child witnesses -- South Africa , Law -- Language
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10267 , http://hdl.handle.net/10948/747 , Child witnesses -- South Africa , Law -- Language
- Description: Children are often required to testify viva voce in criminal trials. The question arises whether children understand what is communicated to them during their testimony in court. In the courtroom, the witness serves as a source of information. In child abuse cases in particular, the meaningful participation of the child in court proceedings is crucial due to the fact that the child is often the key witness, or the only witness, for the prosecution. The proper evaluation of the child’s evidence, however, requires that all role-players involved in the judicial process have a sound knowledge of those aspects which deal with child psychology, especially the cognitive and language abilities of children who testify. The procedure that is followed in court is not understood by the ordinary lay person, even less by children, and the language used is formalistic and very specialized. Legal language in general often contains cognitively and linguistically inappropriate questions which prevent children from relating their stories. Furthermore their responses do not sufficiently reflect their knowledge and experience of the incident of alleged sexual assault. Court language creates serious problems for children and accordingly prevents them from being effective witnesses and taking part in the judicial process in a meaningful way. The researcher, in her capacity as a Regional Court Magistrate, realized that children have limited understanding of the criminal trial process and often become secondary victims as a result of a system that does not acknowledge their cognitive and linguistic developmental levels. The purpose of this research was therefore to test the validity of the following hypotheses: • During the examination of children in a criminal trial developmentally and linguistically inappropriate questions are posed to them; and This results in ineffective communication. Eight court transcripts of criminal cases heard in the regional courts of the Eastern Cape and Mpumalanga by different presiding officers were chosen at random. These transcripts were analyzed and evaluated in order to determine whether questions posed to children when they testify are cognitively and linguistically appropriate. Each question in each of the eight transcripts was numbered and analyzed. The findings of the analysis were categorized in terms of whether they were cognitively and linguistically inappropriate questions. It was clear that the majority of questions put to the child witnesses were cognitively and linguistically inappropriate. It is evident from the evaluation that the manner in which the children’s evidence in court was presented and the way in which they were questioned created a communication barrier which placed a distorted version of events before the court. It is therefore recommended that full account be taken of the cognitive and language capabilities of each particular child in order to elicit reliable information during the child’s testimony. It is of the utmost importance that questioning be conducted in such a fashion so as to ensure that the child witness understands not only the content of the questions, but also what answers or responses are expected from them. At present, acknowledgement of linguistic and cognitive developmental appropriateness, concern and comprehension for the psychology of the child witness are ignored at best, and totally exploited at worst. This lack of knowledge about child development impacts adversely upon the child’s credibility in court. To elevate and enhance the credibility of children, it is of the utmost importance for society in general and court role-players in particular to appreciate the various stages and faces of child development. The main recommendation is that court role-players should make a paradigm shift and children, including victims of sexual assault, should be given the opportunity to tell their own stories in their own language supported by other methods of communication. In evaluating any possible changes, it is necessary to adopt and develop a holistic and multi-disciplinary approach based on scientific principles. A specialized system is required to deal with children in the criminal justice system and innovative methods to achieve this are necessary. There is a strong need to change or adjust the present manner in which the criminal justice system accommodates child witnesses. Such a change or adjustment will be in the best interests of children as envisaged in section 28 of the Constitution of the Republic of South Africa Act.
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- Date Issued: 2008
Constructing confidence intervals for polarization mode dispersion
- Authors: Erlank, Warrick
- Date: 2008
- Subjects: Fiber optics , Polarization (Light)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10571 , http://hdl.handle.net/10948/951 , Fiber optics , Polarization (Light)
- Description: Polarization mode dispersion (PMD) causes significant impairment in high bit-rate optical telecommunications systems. Knowledge of a fibre’s PMD mean value, and the relevant confidence interval, is essential for determining a fibre’s maximum allowable bit-rate. Various methods of confidence interval construction for time series data were tested in this dissertation using simulation. These included the autocovariance-matrix methods as suggested by Box and Jenkins, as well as the more practical and simpler batch means methods. Some of these methods were shown to be significantly better than the standard method of calculating confidence intervals for non time series data. The best of the tested methods were used on actual PMD data. The effect of using polarization scramblers was also tested.
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- Date Issued: 2008