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The effect of different management practices on the feed intake and growth rate of ostrich chicks

  • Authors: Kruger, Anna Christina Magdalena
  • Date: 2008
  • Subjects: Ostriches -- South Africa -- Growth
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:10589 , http://hdl.handle.net/10948/834 , Ostriches -- South Africa -- Growth
  • Description: Different management techniques were studied, at the Kromme Rhee Experimental Farm near Stellenbosch, in order to stimulate feed intake of ostrich chicks and to determine the effect on their growth rate. A first experiment was conducted to determine the effect of different dietary flavourants on the feed intake of ostrich chicks. Ostrich chicks (1-28 days of age), with no previous exposure to flavourants showed a strong preference for salty feed. Another experiment determined the effect of different colourants on the feed intake of ostrich chicks. Exposure of chicks to feed coloured artificially in different colours (green, red, blue and yellow) had no impact on the feed intake of ostrich chicks (1-28 days of age). Throughout the study the dry matter intake was the highest for the control diet, indicating that the provision of coloured feed to ostriches, as practised in this study, will not stimulate feed intake. The effect of feed processing and restriction of water availability for ostrich chicks was also examined. Extrusion reduced microbial counts in feed by 99.7 percent. Feed intake as well as average daily gain of chicks were lowered by both the pelleting and the extrusion process practised in this study. Processing did not have a positive influence on the production of ostrich chicks 6-15 weeks of age. Dry matter intake for chicks subjected to water restriction were the same as for birds receiving water ad libitum. Similarly growth rate as well as feed conversion ratio was not effected by restriction of water, as practised in this study. Another technique studied was to determine the effect of 24h artificial light on feed intake, growth and the behaviour of ostrich chicks (1-28 days of age). A Timeactivity budget revealed that chicks subjected to 24 hours of light spent more time eating (14.7 percent) than those subjected to normal day and night cycles (11.4 percent). In spite of this, no significant difference in feed intake, growth rate and feed conversion ratio was observed for ostrich chicks subjected to different light regimes. The effect of different dietary salt levels on the production of ostrich chicks (8-12 weeks of age) was also determined. The performance of chicks was the best on a diet with a salt inclusion of 1.4 percent.
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  • Date Issued: 2008

The impact of cultural context on web design for e-Government in South Africa

  • Authors: Yeratziotis, Alexandros
  • Date: 2008
  • Subjects: Internet in public administration -- South Africa , Web sites -- Design , Culture
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9741 , http://hdl.handle.net/10948/2116 , Internet in public administration -- South Africa , Web sites -- Design , Culture
  • Description: The role and power of ICT today, particularly the Internet, cannot be underestimated. The Internet has a great impact on the business environment, where a large majority of companies and organisations have made substantial investments in an online presence in the form of websites, as well as the IT infrastructure needed to improve business processes. In terms of websites, research has shown that it is critical to identify the target market of the site and the actual users, and to construct the site according to their specific needs and preferences. This is to a large extent the focus of the field of Human Computer Interaction. It therefore makes perfect sense that many software products and websites fail to meet the users‟ needs, as they are designed mainly by Western designers for Eastern and African users. In essence, the failure is due to the fact that the design does not accommodate the cultural behaviours, understandings and preferences of the intended users, thus making it difficult for them to use and adopt them. This has been confirmed by many researchers who have studied various culture dimensions and their relation to Web design. As mentioned, the role of the Internet in terms of its effect in the business world is becoming increasingly important. However, the Internet could prove to play an influential role in the public sector as well and could therefore be used as a critical tool by government in the form of e-Government. Many countries are adopting e-Government initiatives in an attempt to improve their relations within government itself and with their citizens and businesses. This would help them to render better service delivery and at the same time empower the citizens to also participate in the governance of the country itself. The concept for this dissertation was formulated in terms of three key ingredients: e-Government, culture dimensions and Web design. The purpose of this dissertation is to examine the way a specific culture dimension, referred to as the cultural-context dimension, which focuses on the communication process, can impact in Web design. Once this is achieved, it will be possible to determine how this can positively affect the design of the South African e-Government website so that the overall usability of the site may be improved. The improvements will be justified because the site would then match the cultural behaviours, perceptions and Web design preferences of South African users. In short, the goal of this III dissertation is to provide guidelines and recommendations that will improve the South African e-Government website (www.gov.za) by examining anthropologist Edward Hall‟s cultural-context dimension and its role in the Web design process.
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  • Date Issued: 2008

The perceptions of Chinese tourists of the Western Cape Region travel destination

  • Authors: Hu, Jiang
  • Date: 2008
  • Subjects: Chinese -- Travel -- South Africa -- Western Cape -- Attitudes , Tourism -- South Africa -- Marketing , Tourism -- South Africa
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9365 , http://hdl.handle.net/10948/967 , Chinese -- Travel -- South Africa -- Western Cape -- Attitudes , Tourism -- South Africa -- Marketing , Tourism -- South Africa
  • Description: As a result of significantly improving relationship between South Africa and China, Chinese tourists traveling to South Africa have become a more noticeable group of travelers. More and more Chinese tourists choose South Africa as a tourism destination; especially Cape Town in the Western Cape region for a variety purposes such as relaxation, business and/or shopping. This research investigates the perceptions and motivation of Chinese tourists coming to the Western Cape region of South Africa. The proposed strategy of promoting the Western Cape region as a travel destination can be made based on the perceptions and motivation of Chinese tourists to the Western Cape. The study focuses on clearly understanding the perception of Chinese tourists by studying tourist behaviour and consumer motivation. The process of decision making and factors impacting on decision making are addressed in the research. A survey questionnaire was administered to Chinese tourists visiting South Africa. The primary data received by questionnaire was analyzed to show what actually Chinese tourists consider Western Cape as a travel destination. The Statistical Package of Social Science (SPSS) was utilized for analysis of data collected by the questionnaire. These general groups of data are discussed in the research. There are personal information, the motivation for travelling, and perceptions of respondents in the Western Cape region in South Africa.
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  • Date Issued: 2008

Towards a user centric model for identity and access management within the online environment

  • Authors: Deas, Matthew Burns
  • Date: 2008
  • Subjects: Computers -- Access control , Computer networks -- Security measures
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9780 , http://hdl.handle.net/10948/775 , Computers -- Access control , Computer networks -- Security measures
  • Description: Today, one is expected to remember multiple user names and passwords for different domains when one wants to access on the Internet. Identity management seeks to solve this problem through creating a digital identity that is exchangeable across organisational boundaries. Through the setup of collaboration agreements between multiple domains, users can easily switch across domains without being required to sign in again. However, use of this technology comes with risks of user identity and personal information being compromised. Criminals make use of spoofed websites and social engineering techniques to gain illegal access to user information. Due to this, the need for users to be protected from online threats has increased. Two processes are required to protect the user login information at the time of sign-on. Firstly, user’s information must be protected at the time of sign-on, and secondly, a simple method for the identification of the website is required by the user. This treatise looks at the process for identifying and verifying user information, and how the user can verify the system at sign-in. Three models for identity management are analysed, namely the Microsoft .NET Passport, Liberty Alliance Federated Identity for Single Sign-on and the Mozilla TrustBar for system authentication.
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  • Date Issued: 2008

A code of practice for practitioners in private healthcare: a privacy perspective

  • Authors: Harvey, Brett D
  • Date: 2007
  • Subjects: Information storage and retrieval systems -- Medical care , Medical records -- Data processing , Privacy, Right of Comparative studies
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9735 , http://hdl.handle.net/10948/521 , Information storage and retrieval systems -- Medical care , Medical records -- Data processing , Privacy, Right of Comparative studies
  • Description: Whereas there are various initiatives to standardize the storage, processing and use of electronic patient information in the South African health sector, the sector is fragmented through the adoption of various approaches on national, provincial and district levels. Divergent IT systems are used in the public and private health sectors (“Recommendations of the Committee on …” 2003). Furthermore, general practitioners in some parts of the country still use paper as a primary means of documentation and storage. Nonetheless, the use of computerized systems is increasing, even in the most remote rural areas. This leads to the exposure of patient information to various threats that are perpetuated through the use of information technology. Irrespective of the level of technology adoption by practitioners in private healthcare practice, the security and privacy of patient information remains of critical importance. The disclosure of patient information whether intentional or not, can have dire consequences for a patient. In general, the requirements pertaining to the privacy of patient information are controlled and enforced through the adoption of legislation by the governing body of a country. Compared with developed nations, South Africa has limited legislation to help enforce privacy in the health sector. Conversely, Australia, New Zealand and Canada have some of the most advanced legislative frameworks when it comes to the privacy of patient information. In this dissertation, the Australian, New Zealand, Canadian and South African health sectors and the legislation they have in place to ensure the privacy of health information, will be investigated. Additionally, codes of practice and guidelines on privacy of patient information for GPs, in the afore-mentioned countries, will be investigated to form an idea as to what is needed in creating and formulating a new code of practice for the South African GP, as well as a pragmatic tool (checklist) to check adherence to privacy requirements.
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  • Date Issued: 2007

A comparative analysis of the environmental impact of selected low-income housing developments in the Eastern Cape Province

  • Authors: Kumm, Simon
  • Date: 2007
  • Subjects: Low-income housing -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Housing policy -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:8152 , http://hdl.handle.net/10948/539 , Low-income housing -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Housing policy -- South Africa -- Eastern Cape
  • Description: South Africa has a shortage of affordable housing for its poor. In order to overcome the shortage, a large number of houses need to be built. The bulk building of these houses has an effect on the environment and it is important to note whether or not this impact will be a lasting positive one or not. Governmental policies have recognised the need to create positive, sustainable settlement environments. The degree to which settlements are sustainable and reflect a positive environment is, however, a point of concern. This dissertation analyses and compares four low-income housing developments in the Eastern Cape in order to make proposals on how future low-income developments can impact more positively on their settlement environments, reduce their impact on non-renewable resources and better implement the ideals of the Development Facilitation Act. This was done in order to meet the expectations put in place by Government policies and to correct the historical shortcomings of South Africa’s low-income settlement provision. The method used was to determine, through literature study, a set of factors that most prominently impacted on low-income settlement environments. These were then compiled into a model, which was then used to analyse and compare existing settlements. This elicited a set of conclusions based on the findings and provided strategies for future settlements to follow to meet the research’s stated ideals. The literature study revealed a myriad of important principles that fell into six main categories that impacted on settlement environments. Furthermore, it was discovered that each of these principles should be assessed in the context of their human and natural environments as well as their effect at the scale of the unit, the settlement and the city. The analysis and comparison of the settlements revealed that all six of the model’s categories performed poorly in at least two of the four settlements analysed, a strong indication that the implementation of the model’s principles was not being successfully achieved in low-income settlements. It further revealed specific areas requiring attention in future developments. The analysis also revealed positive areas of implementation from each settlement that can be used in future settlements to meet the stated ideals of creating a positive impact on their settlement environments, reducing their impact on non-renewable resources and better implementing the ideals of the Development Facilitation Act. The study recommends that future settlements avoid the negative practices identified in these settlements and implement the positive strategies proposed for the benefit of future settlement environments.
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  • Date Issued: 2007

A comparison between the game and hunting industries in KwaZulu-Natal and the Eastern Cape

  • Authors: Kobus, Louann
  • Date: 2007
  • Subjects: Big game hunting -- South Africa -- KwaZulu-Natal , Big game hunting -- South Africa -- Eastern Cape , Hunting -- South Africa -- KwaZulu-Natal , Hunting -- South Africa -- Eastern Cape , Game farms -- South Africa -- KwaZulu-Natal , Game farms -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:10590 , http://hdl.handle.net/10948/534 , http://hdl.handle.net/10948/d1011724 , Big game hunting -- South Africa -- KwaZulu-Natal , Big game hunting -- South Africa -- Eastern Cape , Hunting -- South Africa -- KwaZulu-Natal , Hunting -- South Africa -- Eastern Cape , Game farms -- South Africa -- KwaZulu-Natal , Game farms -- South Africa -- Eastern Cape
  • Description: The objectives of this research, were to investigate the characteristics and develop a profile of the game and hunting industries of KwaZulu-Natal, and to undertake a comparison between the game and hunting industries in KwaZulu-Natal and the Eastern Cape. The comparative part of this study was completed using results obtained from a study done in 2002 in the Eastern Cape (van Niekerk, 2002). The main farming activities in KwaZulu-Natal are large livestock production and sugar cane production. In recent years, private landowners in KwaZulu-Natal have undergone a transition from livestock production to game ranching due to the problems faced and the cost implications of the HIV epidemic, stock theft, difficulties faced with changes in the labour laws and the increasing number of land claims against farmers. Although the game and hunting industries are relatively young industries in KwaZulu-Natal they contribute significantly to the economy of the province. Not only is greater conservation of the biodiversity more effective in game ranching but it is also proving to yield great economic returns. The increase in game ranching in recent years is namely due to the monetary value placed on wildlife, the increased value in ecotourism and its value as an earner of foreign exchange, less dependency on unskilled labour than that of livestock farming and lower rates of animal loss through theft compared to that of livestock farming. In KwaZulu-Natal game numbers indicate that impala have the greatest population amongst the respondents, followed by nyala, blesbok, common reedbuck, kudu and blue wildebeest, whilst other game species occur in smaller numbers. Respondents in KwaZulu-Natal indicate that nyala is the largest economic earner for them followed by buffalo, whereas in the Eastern Cape (2002), kudu and springbok provide the greatest income for the province. In KwaZulu-Natal income generated from hunting is second to that of live game sales compared to the Eastern Cape (2002) where hunting is the most important form of game utilisation in terms of income generated. At the time of this study, respondents in KwaZulu-Natal reported an income of R 15 382 397 generated from live sales and R 13 561 459 from hunting. These respondents also indicated that the total value of game utilised annually was in excess of R 30 million. Although game utilisation is occurring on a sustainable basis, there is room for greater utilisation of some game species which, if undertaken correctly, can increase the revenue for the province significantly and also contribute positively to further sustainability of the game populations. KwaZulu-Natal’s competitive advantage is derived from the fact that there is an abundance of game on the ranches, quality trophy animals are available, the number of game species available for hunting and quality of service rendered to hunters by the professional hunters and ranch owners. This study has clearly shown that there is a need for further investigation into the game and hunting industries in KwaZulu-Natal.
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  • Date Issued: 2007

A COP optimized control system for a CO₂ based automotive A/C-system

  • Authors: Rapp, Tobias
  • Date: 2007
  • Subjects: Automobiles -- Air conditioning , Motor vehicles -- Automatic control
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9624 , http://hdl.handle.net/10948/773 , Automobiles -- Air conditioning , Motor vehicles -- Automatic control
  • Description: In the last few years carbon dioxide received increasing attention as a possible replacement for fluorocarbon-based refrigerants used within present automotive A/C system technology. R-134a is harmless to the ozone layer but the greenhouse effect is more than 1300 times higher than that of an equivalent amount of CO2. Alternative refrigerants are natural gasses such as propane and butane, however these gasses are considered explosive. With many objections raised it appears if CO2 will be the future refrigrant for automotive use. One concern with R-744 is its high operating pressure and suction/discharge pressure difference when compared to common refrigeration processes. A major problem with the CO2 cycle is the loss of effciency at high ambient temperatures. With a COP optimized control system for the expansion value based on pressure, temperature and mass flow of the refrigerant, an effective A/C system for CO2 could be deleloped. This resrach offers basic knowledge of refrigerant cycles and gives an overall view of the refrigerant change-over problem. With the results obtained from the experimental work a better understanding of the CO2 cycle and a better understanding towards effective A/C systems have been realized.
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  • Date Issued: 2007

A critical review of the IFIP TC11 Security Conference Series

  • Authors: Gaadingwe, Tshepo Gaadingwe
  • Date: 2007
  • Subjects: Database security , Data protection , Computers -- Access control
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9795 , http://hdl.handle.net/10948/507 , Database security , Data protection , Computers -- Access control
  • Description: Over the past few decades the field of computing has grown and evolved. In this time, information security research has experienced the same type of growth. The increase in importance and interest in information security research is reflected by the sheer number of research efforts being produced by different type of organizations around the world. One such organization is the International Federation for Information Processing (IFIP), more specifically the IFIP Technical Committee 11 (IFIP TC11). The IFIP TC11 community has had a rich history in producing high quality information security specific articles for over 20 years now. Therefore, IFIP TC11 found it necessary to reflect on this history, mainly to try and discover where it came from and where it may be going. Its 20th anniversary of its main conference presented an opportunity to begin such a study of its history. The core belief driving the study being that the future can only be realized and appreciated if the past is well understood. The main area of interest was to find out topics which may have had prevalence in the past or could be considered as "hot" topics. To achieve this, the author developed a systematic process for the study. The underpinning element being the creation of a classification scheme which was used to aid the analysis of the IFIP TC11 20 year's worth of articles. Major themes were identified and trends in the series highlighted. Further discussion and reflection on these trends were given. It was found that, not surprisingly, the series covered a wide variety of topics in the 20 years. However, it was discovered that there has been a notable move towards technically focused papers. Furthermore, topics such as business continuity had just about disappeared in the series while topics which are related to networking and cryptography continue to gain more prevalence.
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  • Date Issued: 2007

A framework for secure mobile computing in healthcare

  • Authors: Thomas, Godwin Dogara Ayenajeh
  • Date: 2007
  • Subjects: Mobile computing
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9789 , http://hdl.handle.net/10948/618 , Mobile computing
  • Description: Mobile computing is rapidly becoming part of healthcare’s electronic landscape, helping to provide better quality of care and reduced cost. While the technology provides numerous advantages to the healthcare industry, it is not without risk. The size and portable nature of mobile computing devices present a highly vulnerable environment, which threaten the privacy and security of health information. Since these devices continually access possibly sensitive healthcare information, it is imperative that these devices are considered for security in order to meet regulatory compliance. In fact, the increase in government and industry regulation to ensure the privacy and security of health information, makes mobile security no longer just desirable, but mandatory. In addition, as healthcare becomes more aware of the need to reinforce patient confidence to gain competitive advantage, it makes mobile security desirable. Several guidelines regarding security best practices exist. Healthcare institutions are thus faced with matching the guidelines offered by best practices, with the legal and regulatory requirements. While this is a valuable question in general, this research focuses on the aspect of considering this question when considering the introduction of mobile computing into the healthcare environment. As a result, this research proposes a framework that will aid IT administrators in healthcare to ensure that privacy and security of health information is extended to mobile devices. The research uses a comparison between the best practices in ISO 17799:2005 and the regulatory requirements stipulated in HIPAA to provide a baseline for the mobile computing security model. The comparison ensures that the model meets healthcare specific industry requirement and international information security standard. In addition, the framework engages the Information Security Management System (ISMS) model based on the ISO 27000 standard. The framework, furthermore, points to existing technical security measurers associated with mobile computing. It is believed that the framework can assist in achieving mobile computing security that is compliant with the requirements in the healthcare industry.
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  • Date Issued: 2007

A general genetic algorithm for one and two dimensional cutting and packing problems

  • Authors: Mancapa, Vusisizwe
  • Date: 2007
  • Subjects: Packaging -- Data processing , Genetic algorithms , Cutting stock problem , Packing for shipment , Manufacturing processes -- Planning
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9602 , http://hdl.handle.net/10948/555 , http://hdl.handle.net/10948/d1011727 , Packaging -- Data processing , Genetic algorithms , Cutting stock problem , Packing for shipment , Manufacturing processes -- Planning
  • Description: Cutting and packing problems are combinatorial optimisation problems. The major interest in these problems is their practical significance, in manufacturing and other business sectors. In most manufacturing situations a raw material usually in some standard size has to be divided or be cut into smaller items to complete the production of some product. Since the cost of this raw material usually forms a significant portion of the input costs, it is therefore desirable that this resource be used efficiently. A hybrid general genetic algorithm is presented in this work to solve one and two dimensional problems of this nature. The novelties with this algorithm are: A novel placement heuristic hybridised with a Genetic Algorithm is introduced and a general solution encoding scheme which is used to encode one dimensional and two dimensional problems is also introduced.
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  • Date Issued: 2007

A methodology for measuring and monitoring IT risk

  • Authors: Tansley, Natalie Vanessa
  • Date: 2007
  • Subjects: Electronic data processing departments -- Security measures , Business -- Data processing -- Security measures , Information resources management , Information technology -- Security measures
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9781 , http://hdl.handle.net/10948/772 , Electronic data processing departments -- Security measures , Business -- Data processing -- Security measures , Information resources management , Information technology -- Security measures
  • Description: The primary objective of the research is to develop a methodology for monitoring and measuring IT risks, strictly focusing on internal controls. The research delivers a methodology whereby an organization can measure its system of internal controls, providing assurance that the risks are at an acceptable level. To achieve the primary objective a number of secondary objectives were addressed: What are the drivers forcing organizations to better corporate governance in managing risk? What is IT risk management, specifically focusing on operational risk. What is internal control and specifically focusing on COSO’s internal control process. Investigation of measurement methods, such as, Balance Scorecards, Critical Success Factors, Maturity Models, Key Performance Indicators and Key Goal Indicators. Investigation of various frameworks such as CobiT, COSO and ISO 17799, ITIL and BS 7799 as to how they manage IT risk relating to internal control.
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  • Date Issued: 2007

A model for integrating information security into the software development life cycle

  • Authors: Futcher, Lynn Ann
  • Date: 2007
  • Subjects: Computer security , Software maintenance
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9737 , http://hdl.handle.net/10948/506 , Computer security , Software maintenance
  • Description: It is within highly integrated technology environments that information security is becoming a focal point for designing, developing and deploying software applications. Ensuring a high level of trust in the security and quality of these applications is crucial to their ultimate success. Therefore, information security has become a core requirement for software applications, driven by the need to protect critical assets and the need to build and preserve widespread trust in computing. However, a common weakness that is inherent in the traditional software development methodologies is the lack of attention given to the security aspects of software development. Most of these methodologies do not explicitly include a standardised method for incorporating information security into their life cycles. Meaningful security can be achieved when information security issues are considered as part of a routine development process, and security safeguards are integrated into the software application throughout its life cycle. This, in turn, will lead to users being more confident to use software applications, and to entrust today's computer systems with their personal information. To build better or more secure software, an improved software development process is required. Security of a software application must be based on the risk associated with the application. In order to understand this risk, the relevant information assets need to be identified together with their threats and vulnerabilities. Therefore, security considerations provide input into every phase of the Software Development Life Cycle (SDLC), from requirements gathering to design, implementation, testing and deployment. This research project presents a Secure Software Development Model (SecSDM) for incorporating information security into all phases of the SDLC, from requirements gathering to systems maintenance. The SecSDM is based on many of the recommendations provided by relevant international standards and best practices, for example, the ISO 7498-2 (1989) standard which addresses the underlying security services and mechanisms that form an integral part of the model.
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  • Date Issued: 2007

An analysis of the influence of phosphorus poisoning on the exhaust emission after treatement systems of light-duty diesel vehicles

  • Authors: Toral del Rio, Maria Isabel
  • Date: 2007
  • Subjects: Diesel motor -- Alternative fuels , Automobiles -- Pollution control devices , Automobiles -- Motors -- Exhaust gas , Motor fuels
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:10405 , http://hdl.handle.net/10948/697 , Diesel motor -- Alternative fuels , Automobiles -- Pollution control devices , Automobiles -- Motors -- Exhaust gas , Motor fuels
  • Description: Climate change has become a discussion topic of exponentially increasing urgency and importance amoung world leaders of all disciplines. These changes are brought about by the emission of so-called Greenhouse gases from various human activities. The primary cause of CO2 emissions is the burning of the Earth’s supply of nonrenewable natural fossil fuels like coal, oil and natural gas. The world first agreed on the prevention of “dangerous” climatic changes at the Earth Summit in 1992. The Kyoto Protocol of 1997 was the first step toward protection of the atmosphere and prescribes restrictions on emission pollutants. Since then the vehicle gas emissions are being controlled by means of different gas emissions norms, like the European Union Norm in Europe. The automotive manufacturers and suppliers are collectively working on reducing overall vehicle emissions. They are focusing on several different emission limiting possibilities, for example improved engine design, special fuel development and exhaust gas treatment systems. The exhaust gas treatment process requires continuous controlling and management of the exhaust gas emissions while driving a vehicle. Certain factors such as high emission temperatures have a negative influence on the life span of these systems. Their functionality and durability is also known to be reduced by the presence of chemical poisoning species like sulphur, phosphorus, zinc and calcium. The chemical poisoning species are produced during combustion of fuel and engine oil. They are therefore contained in the exhaust emissions and can poison the catalyst when passing over it. Phosphorous poisoning is particularly problematic and should be reduced considerably. This study involves the investigation of the phosphorous poisoning process and aims to provide clarity regarding the influences of different fuel and oil compositions on the severity of the process. Engine oil and biodiesel are two major sources of phosphorous poisoning. The phosphorus contained in biodiesel fuel is a natural component and can be minimized during the refining procedure. In contrast to others studies, the biodiesel fuel used during this project was SME (Soya Methyl Ester) with a 20% biodiesel content. This choice of fuel was made because of the increasingly important role that this type of biodiesel is playing in the European market and the future tendency to increase the percentage of biodiesel in the mixture with standard diesel fuel. The phosphorus contained in engine oil is a necessary additive to retain the antioxidant and anti-wear properties of the oil. This study examined the poisoning influences from the most commonly used phosphorus containing oil additive, Zinc Dithiophosphates (ZDDP), as well as a Zn-free, phosphorus containing anti-wear oil additive. This formulation provides information about the phosphorus poisoning process as caused by the engine oil in the absence of Zn in the oil additives. The results show how the phosphorus content in biodiesel fuel affects the functionality of the exhaust gas treatment systems and the importance of reducing the permitted content of phosphorus contained in the fuel. Reducing the phosphorus content in the fuel will conserve the functionality of the exhaust gas treatment systems during their operational life and thereby protect the environmental from emission pollutants. It also provides insight into the differences in the poisoning processes when the phosphorus deposited on the catalyst comes from biodiesel fuel and when it comes from the engine oil. Finally the results also illustrate the influence of different phosphorous forms contained in engine oil additives on the catalyst poisoning process. This information could be used for the development of new oil additive formulations.
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  • Date Issued: 2007

An appraisal of secure, wireless grid-enabled data warehousing

  • Authors: Seelo, Gaolathe
  • Date: 2007
  • Subjects: Data warehousing , Computer security
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9790 , http://hdl.handle.net/10948/602 , http://hdl.handle.net/10948/d1011700 , Data warehousing , Computer security
  • Description: In most research, appropriate collections of data play a significant role in aiding decision-making processes. This is more critical if the data is being accessed across organisational barriers. Further, for the data to be mined and analysed efficiently, to aid decision-making processes, it must be harnessed in a suitably-structured fashion. There is, for example, a need to perform diverse data analyses and interpretation of structured (non-personal) HIV/AIDS patient-data from various quarters in South Africa. Although this data does exist, to some extent, it is autonomously owned and stored in disparate data storages, and not readily available to all interested parties. In order to put this data to meaningful use, it is imperative to integrate and store this data in a manner in which it can be better utilized by all those involved in the ontological field. This implies integration of (and hence, interoperability), and appropriate accessibility to, the information systems of the autonomous organizations providing data and data-processing. This is a typical problem-scenario for a Virtual Inter-Organisational Information System (VIOIS), proposed in this study. The VIOIS envisaged is a hypothetical, secure, Wireless Grid-enabled Data Warehouse (WGDW) that enables IOIS interaction, such as the storage and processing of HIV/AIDS patient-data to be utilized for HIV/AIDS-specific research. The proposed WDGW offers a methodical approach for arriving at such a collaborative (HIV/AIDS research) integrated system. The proposed WDGW is virtual community that consists mainly of data-providers, service-providers and information-consumers. The WGDW-basis resulted from systematic literaturesurvey that covered a variety of technologies and standards that support datastorage, data-management, computation and connectivity between virtual community members in Grid computing contexts. A Grid computing paradigm is proposed for data-storage, data management and computation in the WGDW. Informational or analytical processing will be enabled through data warehousing while connectivity will be attained wirelessly (for addressing the paucity of connectivity infrastructure in rural parts of developing countries, like South Africa).
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  • Date Issued: 2007

An investigation into factors that influence the results of Accounting (Education) 1 at the Technikon Free State

  • Authors: Selesho, Jacob Mohlouwa
  • Date: 2007
  • Subjects: Education, Higher
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:10785 , http://hdl.handle.net/10948/133 , Education, Higher
  • Description: Introduction : South Africa is currently engaged in wide-ranging consultations to formulate a new policy on education in line with the major structural changes currently taking place at the national level. The process has focused mainly on the previous government’s discriminatory policies, which were a cornerstone of apartheid. This research is not concerned so much with policy restructuring as with current pedagogical problems, which are a direct result of policy. During contact with students in different faculties at Technikon Free State over a period of nearly two to three years, made it clear that students experienced major learning problems especially in their first year. The research by Selaledi (1996: p8) seems to reflect one common origin which could be summed up as under-preparedness which, will leads to a high failure and drop-out rate among students. The higher education system is also beginning to respond to the changed social order as reflected, for example, in the changing demographic profile of students’ enrolment. However, the overall effectiveness and efficiency of the system is in doubt, as evidenced by a range of systematic problems (NPHE, 2001:p7-8). These include the overall quantity and quality of graduate research output. The contribution of the study will address aspects of the high failure rate as it has been outlined as a problem in the national plan for higher education. Large numbers of students who attend tertiary institutions are not able to deliver the academic standard of work expected from them. This often results in high failure in other subjects (Esterhuizen, 1995:p15). Technikon Free State declared certain subjects at risk and Accounting Education was included in the list. The high failure rate at tertiary institutions could be ascribed to the difference between the expectations of the lecturers and those of the students (NPHE, 2001:p7-9). Learners who take Accounting at high school spend five years doing the subject. This should give learners a solid grounding for future advanced studies in Accounting. However, according to Fridman (1987:p7-8) this, is not the case, as high school Accounting does not influence the result of first year Accounting. This study proposes to investigate the factors that influence the results of Accounting Education I at Technikon Free State. The study will also determine whether Grade 12 Accounting plays an important role in Accounting Education I results. The research findings may contribute towards a better understanding of the factors that influence academic performance in this field.
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  • Date Issued: 2007

An investigation into the parameters affecting the stability of Dithane

  • Authors: Williams, Nadia
  • Date: 2007
  • Subjects: Fungicides , Dithane
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:10407 , http://hdl.handle.net/10948/645 , Fungicides , Dithane
  • Description: Plant diseases caused by fungi are the number one cause of crop loss worldwide. The application of a fungicide which is a toxic substance applied either to prevent the growth of, or to kill fungi is one of the methods by which plant diseases are controlled. Ethylenebisdithiocarbamate fungicides are a group of surface acting fungicides which control a broad spectrum of fungi and their associated plant diseases. Mancozeb, also commonly known as Dithane, falls under the polymeric Dithiocarbamate fungicides which have several sites of toxicity to the fungal cell. The use of Mancozeb as a fungicide is increasing worldwide due to the advantages of low acute toxicity, low production and short environmental persistence. However, it has one major disadvantage, namely its lack of oxidative stability under ambient conditions. One of the objectives of this study was to characterize the Dithane samples supplied by Dow AgroSciences in terms of their active ingredient, metal and stabilizer content, and to study the thermal decomposition behaviour of Dithane. An attempt was made to correlate the active ingredient analyses with the TGA and DSC results to establish whether the thermal stability and active ingredient content of Dithane could be simultaneously determined by thermal analysis. This approach offered the attractive advantage of shorter analysis times thus allowing the elimination of the more tedious analytical methods employed by Dow AgroSciences. Furthermore, Fourier Transform infra-red characterization of Dithane samples and metal complexes containing HMT, Mn and/or Zn was carried out in order to identify the presence of functional groups and to gain some insight into the nature of the bonding of HMT, sulfate and water. A study of the nature of the bands in the FTIR spectra of these complexes was able to highlight the nature of the bonding but could not give confirmation of the structures of these complexes. In addition to this, the amount of HMT present in the said complexes was determined by the FTIR using the standard addition method. A final objective of the study was to investigate the reconstitution of Dithane by investigating the influence of the addition order of the various constituents on the stability of the final product. The addition order was found to have a definite influence on the thermal stability of the final product as well as on the percentage of fixed HMT in the product, and the kinetics of the Mn/Zn exchange.
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  • Date Issued: 2007

An investigation of indoor air quality assessment in office buildings

  • Authors: Janse van Rensburg, Francois
  • Date: 2007
  • Subjects: Indoor air pollution , Air quality management , Air quality -- Measurement
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:10824 , http://hdl.handle.net/10948/32 , Indoor air pollution , Air quality management , Air quality -- Measurement
  • Description: Over the last several years studies have shown that the quality of indoor air may be worse than outdoor air. People spend as much as 90% of their time indoors, therefor, the associated health risk due to indoor air pollution may be greater than the risk due to outdoor air pollution. Building designs have altered dramatically over the last two decades resulted in "tighter" buildings that rely on sophisticated mechanical systems to provide for the quantity of air required throughout the building. These changes over the years could result in an increased number of complaints received regarding Sick Building Syndrome symptoms. The World Health Organization (WHO) estimates that up to 30% of office buildings world-wide may have significant problems regarding poor indoor air quality (IAQ). This study involves a literature study of the major indoor air pollutants regarding the source of the pollutant, the associated health effects, the measuring techniques available and the results of previous studies conducted on the specific pollutant. Measurements will be taken in two sealed buildings, one an old and the other a new building to identify the major pollutants. A questionnaire was compiled specifically for building occupants and completed by the occupants of both buildings. From the results obtained a step-by-step method for solving indoor air quality (IAQ) problems was proposed. The method was applied and evaluated in a case study of a problem building where indoor air quality related problems were experienced. The results of the study revealed that the major indoor air pollutants are present in old as well as new buildings. The study also revealed that some office workers might be more susceptible than others to the medical reactions cause to human beings by these pollutants. Some concentrations are higher in new buildings than in old buildings. The responses from the questionnaire was evaluated against the results obtained from the measurement study. The step-by-step method in the case study provided a more systematic approach at solving IAQ problems at buildings. Solving indoor air quality problems is a very practical issue and does not necessarily require an investment of expensive high technology equipment, but might merely require a practical approach. Environmental Health Officers can play a major role in providing expert advice when scrutinizing building plans. Environmental Health Officers should empower themselves with the knowledge to do inspections or investigations in office buildings by using the step-by-step method for investigating indoor air quality problems. By addressing indoor air quality problems in buildings, the workers in healthy buildings can increase their productivity with lasting effects on a company’s bottom line.
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  • Date Issued: 2007

Analysing the effect of FSP on MIG-laser hybrid welded 6082-T6 AA joints

  • Authors: Mjali, Kadephi Vuyolwethu
  • Date: 2007
  • Subjects: Friction stir welding
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9610 , http://hdl.handle.net/10948/563 , Friction stir welding
  • Description: Friction Stir Processing (FSP) of aluminium alloys has been used to modify and improve the microstructure and relevant properties of fusion welded aluminium alloys. The effect of FSP on MIG-Laser Hybrid (MLH) welded aluminium alloy 6082-T6 mechanical and microstructural properties has been studied in this research. The FSP process was used on 6mm thick aluminium alloy plates and a tool was designed specifically for FSP, and the effect of varying speeds was analysed before the final FSP welds were made. The effect of FSP was analysed by optical microscopy, tensile, microhardness and fatigue testing. The aim of the study was to determine whether the FSP process has a beneficial influence on the mechanical properties and metallurgical integrity of MIG-Laser Hybrid welded 6082-T6 aluminium alloy with varying gap tolerances. Three welding processes were compared, namely combined Friction Stir Processing on MIG-Laser hybrid process (FSP-MLH), MLH and Friction Stir Welding (FSW) as part of the analysis. (FSP was carried out on MLH components when it was found that FSP is not an entirely complete welding process but rather a finishing process per se.) The aim of this dissertation is to investigate the effects of the FSP process on the weld quality of MLH welded joints and also to compare this to individual processes like FSW and MLH. This investigation was undertaken in order to gain an understanding of the effect of these processes on fatigue performance and microhardness distribution on aluminium alloy 6082-T6 weld joints.
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  • Date Issued: 2007

Analysis of fuel consumption reduction potential through the use of an electrically driven air conditioning compressor

  • Authors: Marais, Charel
  • Date: 2007
  • Subjects: Automobiles -- Air conditioning , Electric vehicles -- Power supply , Automobiles -- Fuel systems , Electric automobiles
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9623 , http://hdl.handle.net/10948/774 , Automobiles -- Air conditioning , Electric vehicles -- Power supply , Automobiles -- Fuel systems , Electric automobiles
  • Description: The disturbing current situation regarding the world climate has initiated a major wave of urgent developments towards decreasing the overall impact of human activities on the living environment. A major role player in this development is the automobile industry that is inherently connected to pollution of various types, be it air, water or noise pollution. There have been drastic changes not only in the technologies employed in producing vehicles and components, but also in the construction and technologies built into modern automobiles to lessen the overall environmental impact of the industry. Noxious emissions have been decreased, overall efficiencies increased and vehicles are becoming more economical with each new generation. Stricter laws dictate that the level of acceptable vehicle emissions is to be decreased ever further and all manufacturers are developing various possibilities to achieve this. With the emergence of hybrid vehicle technology, there was also a sudden development of different electrical systems that were made viable by the higher onboard voltage systems employed in hybrid vehicles. One of these developments was the electrical air conditioning compressor for use in automobile applications. Although it is designed to operate with a higher voltage than the traditional 12V onboard vehicle systems, it is theoretically possible to incorporate it into a 12V system by making use of a DC-DC converter to step up the supply voltage of the electrical compressor sufficiently to allow for its successful operation. The question therefore arises whether it would be feasible and sensible to employ an electrical air conditioning system in conventional combustion engine vehicles from an overall fuel consumption and vehicle emissions point of view. A modelling approach was taken where an overall vehicle driving simulation was created to represent an average modern production vehicle. The simulation was then extended to include the options of incorporating models for both mechanically and electrically driven air conditioning systems. This provides insight into the influences of the air conditioning system on the vehicle’s overall fuel consumption and an opportunity to compare the influences from the two different systems. This study attempted to provide answers to some of the viability questions regarding the incorporation of electrically driven air conditioning systems into vehicles that use standard 12V onboard voltage systems. It was found that the electrical system has definite potential as a viable replacement option for the conventional system should it be combined with an appropriate alternator and equipped with an efficient control system.
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  • Date Issued: 2007
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