Characterising the structural integrity of mechanical formed low carbon steel
- Authors: Victor, Ngea Njoume
- Date: 2012
- Subjects: Carbon steel , Structural analysis (Engineering) , Steel, Structural
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9627 , http://hdl.handle.net/10948/d1012089 , Carbon steel , Structural analysis (Engineering) , Steel, Structural
- Description: The contribution of the clamping force in the technique used in this study to stretch-bend low carbon steel samples was investigated to support the subsequent changes in the microstructure and properties of the formed material with regard to parent material. Although plastic deformation by cold working is known to induce texture or preferred orientation to the grains of a formed material while decreasing its ductility and increasing the strength, as well as inducing residual stress, it is not known how the different directions (rolling, transverse and oblique/45°) of the sheet steel will respond to this stretch bending technique. The first part of the research work involved a thorough literature review on sheet metal forming processes and their effect on the formed material with interest on the above mentioned directions of the sheet. It became clear from the literature overview that cold working of a material will induce strain-hardening which varies with the magnitude of cold work, resulting in changes in the strength and ductility of the material. Besides, when plastic deformation is not uniform (e.g., tensile and compressive) throughout the entire cross section of the formed part, residual stresses remain in the material with the grains been elongated along the direction of the maximum strain. The main parameters that were considered and controlled in this study are as follows: strain experienced / stress induced into the form sample, the sample direction, the stroke length and the clamping torque, the generated radius of curvature. The chapters that follow the literature review, deal with the set-up of the different equipment used in this study, the specimen preparation as well as the recording, the calculation and interpretation of the results. It was found that the stress magnitude that generated the different radii of curvature (120 mm, 150 mm and 185 mm) was between 1 percent & 13 percent higher than the parent material’s yield strength with the lower stress been associated to the smaller radius of curvature and the higher stress to the higher radius. The stress induced into the sample during forming was not only proportional to the stroke length but also to the distance between the punch’s tip and the sample and the sample to the die’s nadir. The clamping torque adopted was restricted to the manual capacity of the operator who used a preset torque wrench to fasten the plate sample into the jig. Plate samples of low carbon steel were cut to angles of 0°, 45°, and 90° to the rolling direction of the sheet material and stretch-bent on a single-action mechanical press to 120 mm, 150 mm, and 185 mm radii of curvature. The preliminary results indicate that stretch-bent samples had increased hardness to the parent plate, in particular below the surface layers up to around 1.1 mm depth. Since there is a well established relationship between hardness, yield and tensile strengths for steel, the yield and tensile strengths of the formed material were estimated using the Nobre et al [34] incremental relation, which relates the linearity between relative increments of hardness and yield strength. Changes were not noticeable at the microstructural level of the formed samples. Meanwhile, samples from which higher plastic deformation stress values were calculated were not those absorbing higher impact energy when Charpy specimen cut from plate and stretch-bent samples were tested. The maximum relieved residual stress in the parent material was predominantly compressive and represents in magnitude approximately 12 percent (average for the three directions) of its original yield strength. In the stretch-bent samples, the relieved residual stress was compressive in the outer curved section with a magnitude about 50 percent of the parent material yield strength and tensile in the inner curved section with a magnitude approximately 25 percent of the parent material yield strength.
- Full Text:
- Date Issued: 2012
- Authors: Victor, Ngea Njoume
- Date: 2012
- Subjects: Carbon steel , Structural analysis (Engineering) , Steel, Structural
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9627 , http://hdl.handle.net/10948/d1012089 , Carbon steel , Structural analysis (Engineering) , Steel, Structural
- Description: The contribution of the clamping force in the technique used in this study to stretch-bend low carbon steel samples was investigated to support the subsequent changes in the microstructure and properties of the formed material with regard to parent material. Although plastic deformation by cold working is known to induce texture or preferred orientation to the grains of a formed material while decreasing its ductility and increasing the strength, as well as inducing residual stress, it is not known how the different directions (rolling, transverse and oblique/45°) of the sheet steel will respond to this stretch bending technique. The first part of the research work involved a thorough literature review on sheet metal forming processes and their effect on the formed material with interest on the above mentioned directions of the sheet. It became clear from the literature overview that cold working of a material will induce strain-hardening which varies with the magnitude of cold work, resulting in changes in the strength and ductility of the material. Besides, when plastic deformation is not uniform (e.g., tensile and compressive) throughout the entire cross section of the formed part, residual stresses remain in the material with the grains been elongated along the direction of the maximum strain. The main parameters that were considered and controlled in this study are as follows: strain experienced / stress induced into the form sample, the sample direction, the stroke length and the clamping torque, the generated radius of curvature. The chapters that follow the literature review, deal with the set-up of the different equipment used in this study, the specimen preparation as well as the recording, the calculation and interpretation of the results. It was found that the stress magnitude that generated the different radii of curvature (120 mm, 150 mm and 185 mm) was between 1 percent & 13 percent higher than the parent material’s yield strength with the lower stress been associated to the smaller radius of curvature and the higher stress to the higher radius. The stress induced into the sample during forming was not only proportional to the stroke length but also to the distance between the punch’s tip and the sample and the sample to the die’s nadir. The clamping torque adopted was restricted to the manual capacity of the operator who used a preset torque wrench to fasten the plate sample into the jig. Plate samples of low carbon steel were cut to angles of 0°, 45°, and 90° to the rolling direction of the sheet material and stretch-bent on a single-action mechanical press to 120 mm, 150 mm, and 185 mm radii of curvature. The preliminary results indicate that stretch-bent samples had increased hardness to the parent plate, in particular below the surface layers up to around 1.1 mm depth. Since there is a well established relationship between hardness, yield and tensile strengths for steel, the yield and tensile strengths of the formed material were estimated using the Nobre et al [34] incremental relation, which relates the linearity between relative increments of hardness and yield strength. Changes were not noticeable at the microstructural level of the formed samples. Meanwhile, samples from which higher plastic deformation stress values were calculated were not those absorbing higher impact energy when Charpy specimen cut from plate and stretch-bent samples were tested. The maximum relieved residual stress in the parent material was predominantly compressive and represents in magnitude approximately 12 percent (average for the three directions) of its original yield strength. In the stretch-bent samples, the relieved residual stress was compressive in the outer curved section with a magnitude about 50 percent of the parent material yield strength and tensile in the inner curved section with a magnitude approximately 25 percent of the parent material yield strength.
- Full Text:
- Date Issued: 2012
Defect in the South African construction industry
- Authors: Le Roux, Martyn
- Date: 2012
- Subjects: Construction industry -- South Africa , Buildings -- Defects -- South Africa , Quality assurance -- Standards -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9711 , http://hdl.handle.net/10948/d1020320
- Description: Lack of quality in the South African construction industry is causing various problems for different stakeholders. The causes of this lack in quality are due to various different attributes. Corruption has become one of the leading causes with regards to lack of quality. Quality assurance can mitigate or eliminate defects through the implementation of a quality management system. Defects manifest primarily through cracking, dampness, detachment, and water leaks. Defects are categorized as structural, subsidence, acoustic and thermal. In terms of time, defects are either patent or latent, and can be discovered through observation, inspection and various tests. The causes of defects are ultimately due to error or omission, either during design or during the construction phases. Defects may also result due to procurement related factors, such as appointment of incompetent contractors. The result of defects is customer dissatisfaction, rework and disputes. Non-conformance to requirements results in rework and this in turn contributes to time and cost overruns. The aim of this research was to investigate the greatest cause that leads to defects in houses; the most common type of defect; and why projects fail in term of project management terms (due to defects). Results of quantitative research amongst professionals within the construction industry in the Western and Eastern Cape of South Africa as well as literature that has been reviewed form the basis of this study. Architectural practices, consulting engineering practices, and general building contractors were selected on a random sample basis, and surveyed using an online questionnaire. The study revealed that inadequate artisan skills is the biggest cause leading to defects in houses, and that cracks are the most frequent type of defect occurring. Projects fail in project management terms because of defects as the construction time of the projects are increased. The study revealed that construction related causes of defects dominate over design related causes. This study should be of value to both construction industry professionals as well as their clients.
- Full Text:
- Date Issued: 2012
- Authors: Le Roux, Martyn
- Date: 2012
- Subjects: Construction industry -- South Africa , Buildings -- Defects -- South Africa , Quality assurance -- Standards -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9711 , http://hdl.handle.net/10948/d1020320
- Description: Lack of quality in the South African construction industry is causing various problems for different stakeholders. The causes of this lack in quality are due to various different attributes. Corruption has become one of the leading causes with regards to lack of quality. Quality assurance can mitigate or eliminate defects through the implementation of a quality management system. Defects manifest primarily through cracking, dampness, detachment, and water leaks. Defects are categorized as structural, subsidence, acoustic and thermal. In terms of time, defects are either patent or latent, and can be discovered through observation, inspection and various tests. The causes of defects are ultimately due to error or omission, either during design or during the construction phases. Defects may also result due to procurement related factors, such as appointment of incompetent contractors. The result of defects is customer dissatisfaction, rework and disputes. Non-conformance to requirements results in rework and this in turn contributes to time and cost overruns. The aim of this research was to investigate the greatest cause that leads to defects in houses; the most common type of defect; and why projects fail in term of project management terms (due to defects). Results of quantitative research amongst professionals within the construction industry in the Western and Eastern Cape of South Africa as well as literature that has been reviewed form the basis of this study. Architectural practices, consulting engineering practices, and general building contractors were selected on a random sample basis, and surveyed using an online questionnaire. The study revealed that inadequate artisan skills is the biggest cause leading to defects in houses, and that cracks are the most frequent type of defect occurring. Projects fail in project management terms because of defects as the construction time of the projects are increased. The study revealed that construction related causes of defects dominate over design related causes. This study should be of value to both construction industry professionals as well as their clients.
- Full Text:
- Date Issued: 2012
Development of a navigation system for an autonomous guided vehicle using android technology
- Authors: Snyman, Christo Johannes
- Date: 2012
- Subjects: Mechatronics , Engeering
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9654 , http://hdl.handle.net/10948/d1020025
- Full Text:
- Date Issued: 2012
- Authors: Snyman, Christo Johannes
- Date: 2012
- Subjects: Mechatronics , Engeering
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9654 , http://hdl.handle.net/10948/d1020025
- Full Text:
- Date Issued: 2012
Electronic communication continuity planning from the perspective of an individual
- Authors: Fouché, Jacques
- Date: 2012
- Subjects: Electronic systems , Internet
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9802 , http://hdl.handle.net/10948/d1012270 , Electronic systems , Internet
- Description: It is beyond doubt that technology has changed the way people in modern society live their daily lives. While a modern society eagerly adopts new technology, the loss of the services provided by these technologies is hardly ever considered. Therefore, this research project will evaluate the importance of communication technology and how critical it is for an individual. Furthermore, this research will provide a framework to improve the availability of current communication technologies from the perspective of the individual.
- Full Text:
- Date Issued: 2012
- Authors: Fouché, Jacques
- Date: 2012
- Subjects: Electronic systems , Internet
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9802 , http://hdl.handle.net/10948/d1012270 , Electronic systems , Internet
- Description: It is beyond doubt that technology has changed the way people in modern society live their daily lives. While a modern society eagerly adopts new technology, the loss of the services provided by these technologies is hardly ever considered. Therefore, this research project will evaluate the importance of communication technology and how critical it is for an individual. Furthermore, this research will provide a framework to improve the availability of current communication technologies from the perspective of the individual.
- Full Text:
- Date Issued: 2012
Exploiting the adaptability of recent information and communication technology to improve the site management process
- Ozumba, Aghaegbuna Obinna Uche
- Authors: Ozumba, Aghaegbuna Obinna Uche
- Date: 2012
- Subjects: Construction industry -- Information technology , Construction industry -- Materials management , Information technology -- Management.
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9705 , http://hdl.handle.net/10948/d1019811
- Description: Construction is a big role player in every economy, and the Site Management Process (SMP) occupies a strategic position in the construction process. Despite existence of appreciable research, technology diffusion in the construction industry is slow. Information and Communication Technology (ICT) implementation processes and products have not adequately and beneficially exploited ICT for improvement of the SMP. This is especially true in developing countries. Without increase in utilisation of ICT, potential benefits for the SMP remain untapped. The aim of the thesis was to ascertain the levels of utilisation of recent ICT developments for the SMP, and thereby gauge the benefits or lack thereof. The theoretical concept of the research is based on the technology transfer sub-concept of adaptation. A fundamentally positivistic view, with principles of objectivist approach was used for the enquiry. The approach included an extensive literature review, and a multi-stage investigation strategy, set in South Africa. Theory reviewed was in the main disciplines of construction science and technology, computer science and technology, and management science. Investigations involved case studies of construction sites, a global ICT survey, a national practitioner survey, and analysis of ICT products. Findings from literature assert the appreciable potential utility in recent ICT, thereby substantiating the adaptability of recent ICT. In addition ICT adoption in the SMP is inadequate and inexpedient, falling short of potential benefits for construction, both generally and in the local context. Furthermore there are challenges to ICT adoption, which could vary according to context. Field research results also point to underutilisation of innovations located in recent ICT. The main challenges in this regard include inadequate knowledge of potential utility of recent ICT, and lack of relevant support and effective approaches to technology integration, in the SMP. Moreover exploitation of the adaptability of recent ICT in the local SMP does not go beyond basic adoption. As such most diffusion occurs only for items requiring an adaptation of usage context or area of application. The results strongly indicate minimal innovativeness in this regard. Frameworks for possible adaptations of existing technologies were also derived, while propositions are made for approaches to improve the utility of recent ICT in the SMP. Through a customised approach, the thesis establishes foundational understanding towards a generic framework for adapting potential utility in ICT to uses in construction, especially in the SMP. Thus the research contributes strategic information to the fledgling CICT body of knowledge, especially in the local context.
- Full Text:
- Date Issued: 2012
- Authors: Ozumba, Aghaegbuna Obinna Uche
- Date: 2012
- Subjects: Construction industry -- Information technology , Construction industry -- Materials management , Information technology -- Management.
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9705 , http://hdl.handle.net/10948/d1019811
- Description: Construction is a big role player in every economy, and the Site Management Process (SMP) occupies a strategic position in the construction process. Despite existence of appreciable research, technology diffusion in the construction industry is slow. Information and Communication Technology (ICT) implementation processes and products have not adequately and beneficially exploited ICT for improvement of the SMP. This is especially true in developing countries. Without increase in utilisation of ICT, potential benefits for the SMP remain untapped. The aim of the thesis was to ascertain the levels of utilisation of recent ICT developments for the SMP, and thereby gauge the benefits or lack thereof. The theoretical concept of the research is based on the technology transfer sub-concept of adaptation. A fundamentally positivistic view, with principles of objectivist approach was used for the enquiry. The approach included an extensive literature review, and a multi-stage investigation strategy, set in South Africa. Theory reviewed was in the main disciplines of construction science and technology, computer science and technology, and management science. Investigations involved case studies of construction sites, a global ICT survey, a national practitioner survey, and analysis of ICT products. Findings from literature assert the appreciable potential utility in recent ICT, thereby substantiating the adaptability of recent ICT. In addition ICT adoption in the SMP is inadequate and inexpedient, falling short of potential benefits for construction, both generally and in the local context. Furthermore there are challenges to ICT adoption, which could vary according to context. Field research results also point to underutilisation of innovations located in recent ICT. The main challenges in this regard include inadequate knowledge of potential utility of recent ICT, and lack of relevant support and effective approaches to technology integration, in the SMP. Moreover exploitation of the adaptability of recent ICT in the local SMP does not go beyond basic adoption. As such most diffusion occurs only for items requiring an adaptation of usage context or area of application. The results strongly indicate minimal innovativeness in this regard. Frameworks for possible adaptations of existing technologies were also derived, while propositions are made for approaches to improve the utility of recent ICT in the SMP. Through a customised approach, the thesis establishes foundational understanding towards a generic framework for adapting potential utility in ICT to uses in construction, especially in the SMP. Thus the research contributes strategic information to the fledgling CICT body of knowledge, especially in the local context.
- Full Text:
- Date Issued: 2012
Factors affecting the adoption and meaningful use of electronic medical records in general practices
- Authors: Masiza, Melissa
- Date: 2012
- Subjects: Medical records -- Data processing , Medical records
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9814 , http://hdl.handle.net/10948/d1018561
- Description: Patients typically enter the healthcare systems at the primary care level from where they are further referred to specialists or hospitals as necessary. In the private healthcare system, primary care is provided by a general practitioner (GP). A GP will refer a patient to a specialist for treatment when necessary, while the GP remains the main healthcare provider. The provision of care is, thus, fragmented which results in continuity of care becoming a challenge. Furthermore, the majority of healthcare providers continue to use paper-based systems to capture and store patient medical data. However, capturing and storing patient medical data via electronic methods, such as Electronic Medical Records (EMRs), has been found to improve continuity of care. Despite this benefit, research reveals that smaller practices are slow to adopt electronic methods of record keeping. Hence this explorative research attempts to identify factors that affect the lack of adoption and meaningful use of EMRs in general practices. Four general practices are surveyed through patient and staff questionnaires, as well as GP interviews. Socio-Technical Systems (STS) theory is used as a theoretical lens to formulate the resulting factors. The findings of the research indicate specific factors that relate to either the social, environmental or technical sub-systems of the socio-technical system, or an overlap between these sub-systems. It is significant to note that within these sub-systems, the social sub-system plays a key role. This is due to various reasons revealed by this research. Furthermore, multiple perceptions emerged from the GP and patient participants during the analysis of the findings. These perceptions may have an influence on the adoption and potential meaningful use of an EMR in a general practice. Additionally, the socio-technical factors identified from this research highlight the challenges related to encouraging the adoption and meaningful use of EMRs. These challenges are introduced by the complexities represented by these factors. Nevertheless, addressing the factors will contribute towards improving the rate of adoption and meaningful use of EMRs in small practices.
- Full Text:
- Date Issued: 2012
Factors affecting the adoption and meaningful use of electronic medical records in general practices
- Authors: Masiza, Melissa
- Date: 2012
- Subjects: Medical records -- Data processing , Medical records
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9814 , http://hdl.handle.net/10948/d1018561
- Description: Patients typically enter the healthcare systems at the primary care level from where they are further referred to specialists or hospitals as necessary. In the private healthcare system, primary care is provided by a general practitioner (GP). A GP will refer a patient to a specialist for treatment when necessary, while the GP remains the main healthcare provider. The provision of care is, thus, fragmented which results in continuity of care becoming a challenge. Furthermore, the majority of healthcare providers continue to use paper-based systems to capture and store patient medical data. However, capturing and storing patient medical data via electronic methods, such as Electronic Medical Records (EMRs), has been found to improve continuity of care. Despite this benefit, research reveals that smaller practices are slow to adopt electronic methods of record keeping. Hence this explorative research attempts to identify factors that affect the lack of adoption and meaningful use of EMRs in general practices. Four general practices are surveyed through patient and staff questionnaires, as well as GP interviews. Socio-Technical Systems (STS) theory is used as a theoretical lens to formulate the resulting factors. The findings of the research indicate specific factors that relate to either the social, environmental or technical sub-systems of the socio-technical system, or an overlap between these sub-systems. It is significant to note that within these sub-systems, the social sub-system plays a key role. This is due to various reasons revealed by this research. Furthermore, multiple perceptions emerged from the GP and patient participants during the analysis of the findings. These perceptions may have an influence on the adoption and potential meaningful use of an EMR in a general practice. Additionally, the socio-technical factors identified from this research highlight the challenges related to encouraging the adoption and meaningful use of EMRs. These challenges are introduced by the complexities represented by these factors. Nevertheless, addressing the factors will contribute towards improving the rate of adoption and meaningful use of EMRs in small practices.
- Full Text:
- Date Issued: 2012
Factors affecting the use of mobile devices for remote data collection in home community based care
- Authors: Shozi, Nobubele Angel
- Date: 2012
- Subjects: Home care services -- Technological innovations , Medical technology , Home care services -- Organisation and administration
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9806 , http://hdl.handle.net/10948/d1012621 , Home care services -- Technological innovations , Medical technology , Home care services -- Organisation and administration
- Description: The health care systems of developing countries, which are already weak, have to carry an additional strain brought on by the burden of infectious diseases. This added strain means that the health care provided is not of the highest quality. The use of home community based care (HCBC) was introduced as an attempt to provide basic health care services to people through the services of community health care workers (CHCW). With the development of HCBC in developing countries and the CHCW playing a vital role in ensuring that the lives of people living with diseases are improved, the need for information and communication technology (ICT) solutions is increased. The information that is collected by the CHCW is paper-based and it cannot be analysed and used efficiently and effectively. This study embraces the adoption of a socio-technical perspective when an ICT solution is introduced in an environment. A socio-technical perspective focuses on three dimensions: the user, the environment and the technology used. These three need to be in coherence to ensure that the technology is used effectively by the user within the environment. Therefore the objective of this study is to identify a list of socio-technical factors that affect CHCWs when they are using mobile phones for data collection purposes in home community based care. In order to achieve this it was necessary to understand how the socio-technical subsystems of the HCBC environment are constituted. The study followed a qualitative approach, including interviews and observations, to collect the data which will best enable the researcher to understand the home community based care environment, its people and the use of the technology to collect data in this environment, in particular mobile phones. A qualitative content analysis approach was followed to analyse the data and constitute a list of factors affecting the use of mobile devices for remote data collection in home community based care. It is hoped that this research will assist to inform the design of appropriate mobile health applications to both ease the burden of CHCWs (i.e. it should be faster and easier to use than paper) and improve the healthcare service provided through enabling access to patient records to all partners in the care continuum.
- Full Text:
- Date Issued: 2012
- Authors: Shozi, Nobubele Angel
- Date: 2012
- Subjects: Home care services -- Technological innovations , Medical technology , Home care services -- Organisation and administration
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9806 , http://hdl.handle.net/10948/d1012621 , Home care services -- Technological innovations , Medical technology , Home care services -- Organisation and administration
- Description: The health care systems of developing countries, which are already weak, have to carry an additional strain brought on by the burden of infectious diseases. This added strain means that the health care provided is not of the highest quality. The use of home community based care (HCBC) was introduced as an attempt to provide basic health care services to people through the services of community health care workers (CHCW). With the development of HCBC in developing countries and the CHCW playing a vital role in ensuring that the lives of people living with diseases are improved, the need for information and communication technology (ICT) solutions is increased. The information that is collected by the CHCW is paper-based and it cannot be analysed and used efficiently and effectively. This study embraces the adoption of a socio-technical perspective when an ICT solution is introduced in an environment. A socio-technical perspective focuses on three dimensions: the user, the environment and the technology used. These three need to be in coherence to ensure that the technology is used effectively by the user within the environment. Therefore the objective of this study is to identify a list of socio-technical factors that affect CHCWs when they are using mobile phones for data collection purposes in home community based care. In order to achieve this it was necessary to understand how the socio-technical subsystems of the HCBC environment are constituted. The study followed a qualitative approach, including interviews and observations, to collect the data which will best enable the researcher to understand the home community based care environment, its people and the use of the technology to collect data in this environment, in particular mobile phones. A qualitative content analysis approach was followed to analyse the data and constitute a list of factors affecting the use of mobile devices for remote data collection in home community based care. It is hoped that this research will assist to inform the design of appropriate mobile health applications to both ease the burden of CHCWs (i.e. it should be faster and easier to use than paper) and improve the healthcare service provided through enabling access to patient records to all partners in the care continuum.
- Full Text:
- Date Issued: 2012
Genetic algorithm for Artificial Neural Network training for the purpose of Automated Part Recognition
- Authors: Buys, Stefan
- Date: 2012
- Subjects: Genetic algorithms , Software architecture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9648 , http://hdl.handle.net/10948/d1008356 , Genetic algorithms , Software architecture
- Description: Object or part recognition is of major interest in industrial environments. Current methods implement expensive camera based solutions. There is a need for a cost effective alternative to be developed. One of the proposed methods is to overcome the hardware, camera, problem by implementing a software solution. Artificial Neural Networks (ANN) are to be used as the underlying intelligent software as they have high tolerance for noise and have the ability to generalize. A colleague has implemented a basic ANN based system comprising of an ANN and three cost effective laser distance sensors. However, the system is only able to identify 3 different parts and needed hard coding changes made by trial and error. This is not practical for industrial use in a production environment where there are a large quantity of different parts to be identified that change relatively regularly. The ability to easily train more parts is required. Difficulties associated with traditional mathematically guided training methods are discussed, which leads to the development of a Genetic Algorithm (GA) based evolutionary training method that overcomes these difficulties and makes accurate part recognition possible. An ANN hybridised with GA training is introduced and a general solution encoding scheme which is used to encode the required ANN connection weights. Experimental tests were performed in order to determine the ideal GA performance and control parameters as studies have indicated that different GA control parameters can lead to large differences in training accuracy. After performing these tests, the training accuracy was analyzed by investigation into GA performance as well as hardware based part recognition performance. This analysis identified the ideal GA control parameters when training an ANN for the purpose of part recognition and showed that the ANN generally trained well and could generalize well on data not presented to it during training.
- Full Text:
- Date Issued: 2012
- Authors: Buys, Stefan
- Date: 2012
- Subjects: Genetic algorithms , Software architecture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9648 , http://hdl.handle.net/10948/d1008356 , Genetic algorithms , Software architecture
- Description: Object or part recognition is of major interest in industrial environments. Current methods implement expensive camera based solutions. There is a need for a cost effective alternative to be developed. One of the proposed methods is to overcome the hardware, camera, problem by implementing a software solution. Artificial Neural Networks (ANN) are to be used as the underlying intelligent software as they have high tolerance for noise and have the ability to generalize. A colleague has implemented a basic ANN based system comprising of an ANN and three cost effective laser distance sensors. However, the system is only able to identify 3 different parts and needed hard coding changes made by trial and error. This is not practical for industrial use in a production environment where there are a large quantity of different parts to be identified that change relatively regularly. The ability to easily train more parts is required. Difficulties associated with traditional mathematically guided training methods are discussed, which leads to the development of a Genetic Algorithm (GA) based evolutionary training method that overcomes these difficulties and makes accurate part recognition possible. An ANN hybridised with GA training is introduced and a general solution encoding scheme which is used to encode the required ANN connection weights. Experimental tests were performed in order to determine the ideal GA performance and control parameters as studies have indicated that different GA control parameters can lead to large differences in training accuracy. After performing these tests, the training accuracy was analyzed by investigation into GA performance as well as hardware based part recognition performance. This analysis identified the ideal GA control parameters when training an ANN for the purpose of part recognition and showed that the ANN generally trained well and could generalize well on data not presented to it during training.
- Full Text:
- Date Issued: 2012
Guidelines for the adaptation of the TETRA educational programme at Nelson Mandela Metropolitan University to address human behavioural issues
- Authors: Fouche Nico Pieter
- Date: 2012
- Subjects: Nelson Mandela Metropolitan University -- Communication systems , Human behavior
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9801 , http://hdl.handle.net/10948/d1012248 , Nelson Mandela Metropolitan University -- Communication systems , Human behavior
- Description: Information is a vitally important asset to organizations and the information should be protected to sustain the value it provides to the organization. Information is transferred via different mediums in these organizations. An example would be Terrestrial Trunked Radio or TETRA, which is utilized within organizations to provide a technically very secure form of digital radio communication. TETRA is a communications technology that is currently being successfully used throughout the world for secure, reliable and robust critical communication. TETRA is used by Public Safety and Security (PSS) and transportation sectors, amongst others. PSS includes police officers, fire marshals and emergency medical units who require protected and accurate information that could influence decisions that could make difference between life and death. The TETRA educational programme offered by the TETRA Academy at the Nelson Mandela Metropolitan University (NMMU), educates TETRA users in various aspects of the TETRA standard. TETRA is viewed as a technically very secure communication standard, as it utilizes security features such as mutual authentication, air interface encryption, end-to-end encryption, jamming detection and ambience listening, amongst other security techniques to ensure that the information traversing through the network is kept secure. The TETRA educational programme material includes many physical and technical controls to assist TETRA users in protecting information. However, to what extent does the TETRA educational programme address operational controls? Operational controls address what is often referred to as the weakest link in information security – human behavioural issues. Humans can be exploited through human manipulation attacks, which include social engineering and bribery. Therefore, this study argues towards adapting the TETRA educational programme offered at the NMMU to address these human behavioural issues.
- Full Text:
- Date Issued: 2012
- Authors: Fouche Nico Pieter
- Date: 2012
- Subjects: Nelson Mandela Metropolitan University -- Communication systems , Human behavior
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9801 , http://hdl.handle.net/10948/d1012248 , Nelson Mandela Metropolitan University -- Communication systems , Human behavior
- Description: Information is a vitally important asset to organizations and the information should be protected to sustain the value it provides to the organization. Information is transferred via different mediums in these organizations. An example would be Terrestrial Trunked Radio or TETRA, which is utilized within organizations to provide a technically very secure form of digital radio communication. TETRA is a communications technology that is currently being successfully used throughout the world for secure, reliable and robust critical communication. TETRA is used by Public Safety and Security (PSS) and transportation sectors, amongst others. PSS includes police officers, fire marshals and emergency medical units who require protected and accurate information that could influence decisions that could make difference between life and death. The TETRA educational programme offered by the TETRA Academy at the Nelson Mandela Metropolitan University (NMMU), educates TETRA users in various aspects of the TETRA standard. TETRA is viewed as a technically very secure communication standard, as it utilizes security features such as mutual authentication, air interface encryption, end-to-end encryption, jamming detection and ambience listening, amongst other security techniques to ensure that the information traversing through the network is kept secure. The TETRA educational programme material includes many physical and technical controls to assist TETRA users in protecting information. However, to what extent does the TETRA educational programme address operational controls? Operational controls address what is often referred to as the weakest link in information security – human behavioural issues. Humans can be exploited through human manipulation attacks, which include social engineering and bribery. Therefore, this study argues towards adapting the TETRA educational programme offered at the NMMU to address these human behavioural issues.
- Full Text:
- Date Issued: 2012
Guidelines for the design of a mobile phone application for deaf people
- Authors: Yeratziotis, George
- Date: 2012
- Subjects: Mobile communication systems -- Design and construction , Deaf -- Means of communication
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9750 , http://hdl.handle.net/10948/d1007925 , Mobile communication systems -- Design and construction , Deaf -- Means of communication
- Description: Deaf people in South Africa are no longer a minority group and their needs regarding communication and interaction must therefore be taken into consideration. This demographic does not communicate and interact in the same way as hearing people, which means that any existing usability or accessibility guidelines do not apply. As a result, Deaf people do not have access to information in the same way that a hearing person does. Providing proper access to Information and Communications Technology services, which meet their particular needs, will help the hearing impaired to better integrate into society. The importance of demolishing the communication barrier between the hearing and the hearing impaired is very important. Many people assume that sign language is somehow based on oral language. However, this is not the case. Sign languages are natural visual-spatial languages, and form a contrast with spoken languages which are auditory-vocal based. Acknowledging this fact in 2008, the South African Sign Language Policy Implementation Conference together with several governmental bodies suggested that South African Sign Language should become recognized as the 12th official language of South Africa. Due to the fact that cell phone technology continues to evolve, it will remain a tool of communication upon which Deaf people heavily rely on. The cell phone fulfils a basic need for everyone, but especially for the Deaf demographic as they rely on the short message system to communicate. Deaf people are currently faced with a lack of appropriate mobile phone applications, which would allow them to communicate with hearing as well as deaf people. The primary objective of this research was therefore to make mobile technology equally accessible meaning usable to members of the Deaf demographic. The focus of the research was to investigate the communication barrier and a range of variables that can influence the deaf user’s experience. Topics such as user interface design, usability and interaction were investigated. The outcome of this research was to propose a set of guidelines that, when applied to the design of a website or to phone application accessibility, would ensure communication and interaction from a deaf user. The proposed set of guidelines was then applied to the design of the high fidelity prototype of a mobile phone application. The specific application is a messaging phone application that allows deaf users to communicate with other deaf and hearing users via short message system. A mobile phone application that allows Deaf people to send and receive messages based on the sign language alphabet. The application was named Signchat. Purpose of this was to visibly display how the guidelines were implemented in Signchat. While Signchat’s main purpose is to accommodate the needs of Deaf people, it is also a learning tool and an application that bridges the gap by allowing deaf and hearing users to communicate.
- Full Text:
- Date Issued: 2012
- Authors: Yeratziotis, George
- Date: 2012
- Subjects: Mobile communication systems -- Design and construction , Deaf -- Means of communication
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9750 , http://hdl.handle.net/10948/d1007925 , Mobile communication systems -- Design and construction , Deaf -- Means of communication
- Description: Deaf people in South Africa are no longer a minority group and their needs regarding communication and interaction must therefore be taken into consideration. This demographic does not communicate and interact in the same way as hearing people, which means that any existing usability or accessibility guidelines do not apply. As a result, Deaf people do not have access to information in the same way that a hearing person does. Providing proper access to Information and Communications Technology services, which meet their particular needs, will help the hearing impaired to better integrate into society. The importance of demolishing the communication barrier between the hearing and the hearing impaired is very important. Many people assume that sign language is somehow based on oral language. However, this is not the case. Sign languages are natural visual-spatial languages, and form a contrast with spoken languages which are auditory-vocal based. Acknowledging this fact in 2008, the South African Sign Language Policy Implementation Conference together with several governmental bodies suggested that South African Sign Language should become recognized as the 12th official language of South Africa. Due to the fact that cell phone technology continues to evolve, it will remain a tool of communication upon which Deaf people heavily rely on. The cell phone fulfils a basic need for everyone, but especially for the Deaf demographic as they rely on the short message system to communicate. Deaf people are currently faced with a lack of appropriate mobile phone applications, which would allow them to communicate with hearing as well as deaf people. The primary objective of this research was therefore to make mobile technology equally accessible meaning usable to members of the Deaf demographic. The focus of the research was to investigate the communication barrier and a range of variables that can influence the deaf user’s experience. Topics such as user interface design, usability and interaction were investigated. The outcome of this research was to propose a set of guidelines that, when applied to the design of a website or to phone application accessibility, would ensure communication and interaction from a deaf user. The proposed set of guidelines was then applied to the design of the high fidelity prototype of a mobile phone application. The specific application is a messaging phone application that allows deaf users to communicate with other deaf and hearing users via short message system. A mobile phone application that allows Deaf people to send and receive messages based on the sign language alphabet. The application was named Signchat. Purpose of this was to visibly display how the guidelines were implemented in Signchat. While Signchat’s main purpose is to accommodate the needs of Deaf people, it is also a learning tool and an application that bridges the gap by allowing deaf and hearing users to communicate.
- Full Text:
- Date Issued: 2012
Guidelines to establish an e-safety awareness in South Africa
- Authors: De Lange, Mariska
- Date: 2012
- Subjects: Internet and children--Safety measures , Internet in education , Online etiquette
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9747 , http://hdl.handle.net/10948/d1007863 , Internet and children--Safety measures , Internet in education , Online etiquette
- Description: Information and Communication Technology (ICT) has become an integral part of almost every individual’s life. Although ICT, particularly the Internet, might offer numerous opportunities, individuals should also be aware of the associated risks. Especially with the younger generations who can be seen as being the most vulnerable to online dangers as they are becoming more involved in online activities. Children are utilizing new technologies from an early age and should know how to keep themselves and others safe whilst accessing the Internet. However, most of them do not have the required knowledge and expertise to protect themselves. This is because, under most circumstances, the parents do not understand their children’s online behaviours and activities and are, therefore, unable to teach their children how to utilize it safe and responsibly. A school can be seen as the perfect place to teach children safe online behaviours. However, there is currently a definite lack of e-Safety in South African schools, because no e-Safety policies are in place and there is little or nothing in curricula with regards to e-Safety. This can lead to additional concerns. The primary objective of this research study is, therefore, to develop, motivate and verify a framework that might contribute towards the development of an e-Safety culture. This e-Safety culture should allow individuals to adapt their behavior towards the secure utilization of ICT. However, for the purpose of this research study, the focus will primarily be on learners from primary and secondary schools.
- Full Text:
- Date Issued: 2012
- Authors: De Lange, Mariska
- Date: 2012
- Subjects: Internet and children--Safety measures , Internet in education , Online etiquette
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9747 , http://hdl.handle.net/10948/d1007863 , Internet and children--Safety measures , Internet in education , Online etiquette
- Description: Information and Communication Technology (ICT) has become an integral part of almost every individual’s life. Although ICT, particularly the Internet, might offer numerous opportunities, individuals should also be aware of the associated risks. Especially with the younger generations who can be seen as being the most vulnerable to online dangers as they are becoming more involved in online activities. Children are utilizing new technologies from an early age and should know how to keep themselves and others safe whilst accessing the Internet. However, most of them do not have the required knowledge and expertise to protect themselves. This is because, under most circumstances, the parents do not understand their children’s online behaviours and activities and are, therefore, unable to teach their children how to utilize it safe and responsibly. A school can be seen as the perfect place to teach children safe online behaviours. However, there is currently a definite lack of e-Safety in South African schools, because no e-Safety policies are in place and there is little or nothing in curricula with regards to e-Safety. This can lead to additional concerns. The primary objective of this research study is, therefore, to develop, motivate and verify a framework that might contribute towards the development of an e-Safety culture. This e-Safety culture should allow individuals to adapt their behavior towards the secure utilization of ICT. However, for the purpose of this research study, the focus will primarily be on learners from primary and secondary schools.
- Full Text:
- Date Issued: 2012
Increasing the gap tolerance in friction stir welded joints of AA6082-T6
- Authors: Oyedemi, Kayode
- Date: 2012
- Subjects: Friction stir welding , Aluminum alloys -- Welding , Welding
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9628 , http://hdl.handle.net/10948/d1012325 , Friction stir welding , Aluminum alloys -- Welding , Welding
- Description: This research project was conducted to increase weld gap tolerance in Friction Stir Welding (FSW) of 8 mm thick aluminum alloy 6082 – T6. Investigation was done on I-STIR PDS platform and a Johnford milling machine. The research project involved tool-pin design with varying re-entrant features and varying parameters as a method of weld gap closing to produce successful welds. Direction of spindle rotation and dwell time were established as part of a preliminary study. Clockwise spindle rotation with 20 seconds dwell time allows sufficient plasticity and improved material flow which assisted in achieving welds with prior 30 percent weld gap of the plate thickness. Final welds were made using three rotational speeds and feed rates with sufficient plunging to prevent root defects. Analysis of the results were detailed which include vickers microhardness test, tensile test and metallographic observation to access the suitability of the weld structure. From the set of tool-pins designed, the flare tool-pin gave a well-defined weld nugget with improved stirring at the weld root. Also, with a concave shoulder, right hand threaded tool-pin and counterclockwise flutes undergoing a clockwise spindle rotation, plasticized material flow was upward which was beneficial in reducing the amount of plate thinning. The right hand thread counter clockwise flute with a flute machined in the foot exhibited superior tensile strength for welds containing 30 percent weld gap.
- Full Text:
- Date Issued: 2012
- Authors: Oyedemi, Kayode
- Date: 2012
- Subjects: Friction stir welding , Aluminum alloys -- Welding , Welding
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9628 , http://hdl.handle.net/10948/d1012325 , Friction stir welding , Aluminum alloys -- Welding , Welding
- Description: This research project was conducted to increase weld gap tolerance in Friction Stir Welding (FSW) of 8 mm thick aluminum alloy 6082 – T6. Investigation was done on I-STIR PDS platform and a Johnford milling machine. The research project involved tool-pin design with varying re-entrant features and varying parameters as a method of weld gap closing to produce successful welds. Direction of spindle rotation and dwell time were established as part of a preliminary study. Clockwise spindle rotation with 20 seconds dwell time allows sufficient plasticity and improved material flow which assisted in achieving welds with prior 30 percent weld gap of the plate thickness. Final welds were made using three rotational speeds and feed rates with sufficient plunging to prevent root defects. Analysis of the results were detailed which include vickers microhardness test, tensile test and metallographic observation to access the suitability of the weld structure. From the set of tool-pins designed, the flare tool-pin gave a well-defined weld nugget with improved stirring at the weld root. Also, with a concave shoulder, right hand threaded tool-pin and counterclockwise flutes undergoing a clockwise spindle rotation, plasticized material flow was upward which was beneficial in reducing the amount of plate thinning. The right hand thread counter clockwise flute with a flute machined in the foot exhibited superior tensile strength for welds containing 30 percent weld gap.
- Full Text:
- Date Issued: 2012
Managing an information security policy architecture : a technical documentation perspective
- Maninjwa, Prosecutor Mvikeli
- Authors: Maninjwa, Prosecutor Mvikeli
- Date: 2012
- Subjects: Computer security -- Management , Computer architecture , Data protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9825 , http://hdl.handle.net/10948/d1020757
- Description: Information and the related assets form critical business assets for most organizations. Organizations depend on their information assets to survive and to remain competitive. However, the organization’s information assets are faced with a number of internal and external threats, aimed at compromising the confidentiality, integrity and/or availability (CIA) of information assets. These threats can be of physical, technical, or operational nature. For an organization to successfully conduct its business operations, information assets should always be protected from these threats. The process of protecting information and its related assets, ensuring the CIA thereof, is referred to as information security. To be effective, information security should be viewed as critical to the overall success of the organization, and therefore be included as one of the organization’s Corporate Governance sub-functions, referred to as Information Security Governance. Information Security Governance is the strategic system for directing and controlling the organization’s information security initiatives. Directing is the process whereby management issues directives, giving a strategic direction for information security within an organization. Controlling is the process of ensuring that management directives are being adhered to within an organization. To be effective, Information Security Governance directing and controlling depend on the organization’s Information Security Policy Architecture. An Information Security Policy Architecture is a hierarchical representation of the various information security policies and related documentation that an organization has used. When directing, management directives should be issued in the form of an Information Security Policy Architecture, and controlling should ensure adherence to the Information Security Policy Architecture. However, this study noted that in both literature and organizational practices, Information Security Policy Architectures are not comprehensively addressed and adequately managed. Therefore, this study argues towards a more comprehensive Information Security Policy Architecture, and the proper management thereof.
- Full Text:
- Date Issued: 2012
- Authors: Maninjwa, Prosecutor Mvikeli
- Date: 2012
- Subjects: Computer security -- Management , Computer architecture , Data protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9825 , http://hdl.handle.net/10948/d1020757
- Description: Information and the related assets form critical business assets for most organizations. Organizations depend on their information assets to survive and to remain competitive. However, the organization’s information assets are faced with a number of internal and external threats, aimed at compromising the confidentiality, integrity and/or availability (CIA) of information assets. These threats can be of physical, technical, or operational nature. For an organization to successfully conduct its business operations, information assets should always be protected from these threats. The process of protecting information and its related assets, ensuring the CIA thereof, is referred to as information security. To be effective, information security should be viewed as critical to the overall success of the organization, and therefore be included as one of the organization’s Corporate Governance sub-functions, referred to as Information Security Governance. Information Security Governance is the strategic system for directing and controlling the organization’s information security initiatives. Directing is the process whereby management issues directives, giving a strategic direction for information security within an organization. Controlling is the process of ensuring that management directives are being adhered to within an organization. To be effective, Information Security Governance directing and controlling depend on the organization’s Information Security Policy Architecture. An Information Security Policy Architecture is a hierarchical representation of the various information security policies and related documentation that an organization has used. When directing, management directives should be issued in the form of an Information Security Policy Architecture, and controlling should ensure adherence to the Information Security Policy Architecture. However, this study noted that in both literature and organizational practices, Information Security Policy Architectures are not comprehensively addressed and adequately managed. Therefore, this study argues towards a more comprehensive Information Security Policy Architecture, and the proper management thereof.
- Full Text:
- Date Issued: 2012
Measuring the competitiveness of small, medium and micro enterprice contractors through the use of the register of contractors
- Gasa, Zanele Bridgette Nompumelelo
- Authors: Gasa, Zanele Bridgette Nompumelelo
- Date: 2012
- Subjects: Construction industry -- South Africa , Construction contracts -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9699 , http://hdl.handle.net/10948/d1014325
- Description: This research focuses on and summarises the methodology followed to demonstrate that the South African construction industry can use the Construction Registers Service, in particular the Register of Contractors, as a tool to measure the competitiveness of Small, Micro and Medium Enterprises (SMMEs). The Register of Contractors (RoC) was developed by the Construction Industry Development Board (cidb) in terms of the Construction Industry Development Board (cidb) Act 38 of 2000. As a tool, it was designed to offer a basis for sustainable constructor development, growth, improved delivery, performance and sustainable empowerment. It was also developed to be used by the construction industry to, inter alia, and provide statistical data which would enable the construction industry to better understand the contracting capacity in South Africa. Beyond providing the statistical data, the register of contractors was meant to be enhanced with functionalities that would measure the growth and performance of contractors as they apply business practices that improve their value offering to the construction industry as a whole. This research looks at how this tool can be used by the construction industry to measure the competitiveness of the contractors within the selected grades, with the intent of demonstrating the overall value of the RoC as a tool. The research undertaken looks at how the use of the RoC can measure the competitiveness of a targeted group of small contractors. The research limits itself to the entry levels of contractors registered with the cidb between grades 2 and 5 with a view to establish a benchmark for contractor competitiveness within those bands. The research further proves the correlation between contractor capability and the ‘ability’ to be competitive in growing their value proposition and businesses. The unit of study for the purposes of this research is at firm level drawing from a reflection on who is an active participant in the South African construction industry particularly as it pertains to the smaller contractors within the targeted group elucidated above. The focus of the research is on the efficacy of the RoC as a tool that identifies the areas needing targeted development to support SMMEs and the subsequent demonstration of improved business processes within that sector. The qualitative research methodology was followed through this study as its nature was such that there was no requirement to rely only entirely on statistics or numbers due to the articulated problem there needed to be a qualitative enquiry into data needed which would adequately land to a significant synthesis on the responses and arrive at suitable solutions to the identified problem. The qualitative research methodology followed by this study was used to gain insight into the construction SMMEs’ attitudes towards the sector within which they trade, their behaviours, their value systems [to the extent where this was possible], their concerns, their motivations and aspirations. All of these, the study concluded that they inform the business decisions which the SMMEs make. How structured information was collected and analysed provided a synthesis of themes and aided in extracting meaning. The main findings of the research were that there is no shared understanding within the local construction industry of what contractor competitiveness is and to what extent it would benefit both the industry and the SMME sector. As a result of this competitiveness could not be measured and there was no clarity as to what tools of measure could be used to forecast the capabilities of the industry. This research was focused on exploring how the RoC can be used to measure improved capability and competitiveness on the part of SMME contractors. The implications of these findings are that there would now be improved and measurable competitiveness allowing the contractors to bid for work both within their provincial regions but also outside of their geographical location and to measure their growth as they achieve higher grading statuses within the register of contractors (RoC). The efficacy of contractor development programmes would also improve as they go beyond enhancing contractor capacity but also include competence improvements, training for business acumen, improved capability and innovation. The conclusion is that South Africa’s construction industry could achieve sustainable development and growth as a result of SMME contractors whose competitiveness would have been measured through the use of the RoC tool. The main recommendation is that there be a clear understanding of competitiveness and what its benefits to the South African construction industry are whilst at the same time the RoC is acknowledged as the tool embedded with functionalities able to measure this competitiveness amongst graded contractors. The RoC would allow construction clients to not only measure contractor competitiveness but also that they may have an improved ability to measure the direct impacts of contractor development interventions. , Lolucubungulo lugxile ekubhekeni izimo ezinqala ngaphakathi komkhakha wezokwakha. Lubuka igalelo losonkontilaka abasebancane kulomkhakha ekuzithuthukiseni kanti futhi nemizamo eyenziwe uHulumeni endimeni edlalwe uhlu olushicilwelwe iBhodi yomkhakha wezokwakha (i-cidb). Umbhali walolucubungulo ukholelwa ekutheni loluhlu lungasetshenziswa hhayi kuphela ekuthuthikiseni ononkontilaka kodwa futhi ekwenzeni ukuthi bakhule kulo lona loluhlu baze bakwazi ukuthola amathuba angcono emisebenzi. Uhlu ekukhulunywa ngalo lapha lwashicilelwa i-cidb ngomgomo womthetho kaHulumeni we-Act 38 of 2000. Luyithuluzi elenzelwe ukuba likhulise umkhakha wezokwakha, lithuthukise osomabhizinisi abasebancane, likhuthaze imigomo efanelekile ekwakheni (improved delivery). Enye injongo yokushicilela lelithuluzi kwakuwukwenzela ukuthi kwaziwe inani labo osonkontilaka, ubulili babo nokuthi bagxile-phi ngokwezindawo zokusebenza. Konke loku kwakufanele ukuze uHulumeni kanye nabanye abaqashi bazi ukuthi uma kusikelwana ngemisebenzi bangaki na ononkontilaka abazokwazi ukufeza izidingo zemiphakathi esiphila kuyo? Lolucubungulo luzobheka ithuluzi elasungulwa umkhakha wokwakha ekutheni lingakwazi na ukudlondlobalisa osonkontilaka abasafufusa phakathi kwalemikhakha (grades) ababekwe kuyo? Kuzobhekwa futhi ubugugu balo lona lelithuluzi. Akuzoqxilwa kubo bonke osonkontilaka, kodwa kulabo abasabancane ngokwamabhizinisi abo ababekwe emazingeni kusukela ku-2 kuya ku-5 ngokoshicilelo le-cidb. Kuzobhekwa amakhono abo labosonkontilaka, kubhekwe futhi izinkomba ezingabadlondlobalisa ngokwamabhizinisi. Okunye okuhloswe yilolucubungulo ukubheka ukuthi umkhakha wezokwakha uyakwazi na ukukhiqiza amathuba anele isikhathi eside kwenzelwa osonkotilaka belu nokuthi uyakwazi na ukuqhubeka wakhe amathuba azokhuthaza ukukhula kwabo. Ekugcineni okufanele kufezwe yilolucubungulo wukuthi uhlu olushicilelwe losonkontilaka lungasiza ekukhuthazeni udlondlobalo losonkontilaka abancane.
- Full Text:
- Date Issued: 2012
- Authors: Gasa, Zanele Bridgette Nompumelelo
- Date: 2012
- Subjects: Construction industry -- South Africa , Construction contracts -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9699 , http://hdl.handle.net/10948/d1014325
- Description: This research focuses on and summarises the methodology followed to demonstrate that the South African construction industry can use the Construction Registers Service, in particular the Register of Contractors, as a tool to measure the competitiveness of Small, Micro and Medium Enterprises (SMMEs). The Register of Contractors (RoC) was developed by the Construction Industry Development Board (cidb) in terms of the Construction Industry Development Board (cidb) Act 38 of 2000. As a tool, it was designed to offer a basis for sustainable constructor development, growth, improved delivery, performance and sustainable empowerment. It was also developed to be used by the construction industry to, inter alia, and provide statistical data which would enable the construction industry to better understand the contracting capacity in South Africa. Beyond providing the statistical data, the register of contractors was meant to be enhanced with functionalities that would measure the growth and performance of contractors as they apply business practices that improve their value offering to the construction industry as a whole. This research looks at how this tool can be used by the construction industry to measure the competitiveness of the contractors within the selected grades, with the intent of demonstrating the overall value of the RoC as a tool. The research undertaken looks at how the use of the RoC can measure the competitiveness of a targeted group of small contractors. The research limits itself to the entry levels of contractors registered with the cidb between grades 2 and 5 with a view to establish a benchmark for contractor competitiveness within those bands. The research further proves the correlation between contractor capability and the ‘ability’ to be competitive in growing their value proposition and businesses. The unit of study for the purposes of this research is at firm level drawing from a reflection on who is an active participant in the South African construction industry particularly as it pertains to the smaller contractors within the targeted group elucidated above. The focus of the research is on the efficacy of the RoC as a tool that identifies the areas needing targeted development to support SMMEs and the subsequent demonstration of improved business processes within that sector. The qualitative research methodology was followed through this study as its nature was such that there was no requirement to rely only entirely on statistics or numbers due to the articulated problem there needed to be a qualitative enquiry into data needed which would adequately land to a significant synthesis on the responses and arrive at suitable solutions to the identified problem. The qualitative research methodology followed by this study was used to gain insight into the construction SMMEs’ attitudes towards the sector within which they trade, their behaviours, their value systems [to the extent where this was possible], their concerns, their motivations and aspirations. All of these, the study concluded that they inform the business decisions which the SMMEs make. How structured information was collected and analysed provided a synthesis of themes and aided in extracting meaning. The main findings of the research were that there is no shared understanding within the local construction industry of what contractor competitiveness is and to what extent it would benefit both the industry and the SMME sector. As a result of this competitiveness could not be measured and there was no clarity as to what tools of measure could be used to forecast the capabilities of the industry. This research was focused on exploring how the RoC can be used to measure improved capability and competitiveness on the part of SMME contractors. The implications of these findings are that there would now be improved and measurable competitiveness allowing the contractors to bid for work both within their provincial regions but also outside of their geographical location and to measure their growth as they achieve higher grading statuses within the register of contractors (RoC). The efficacy of contractor development programmes would also improve as they go beyond enhancing contractor capacity but also include competence improvements, training for business acumen, improved capability and innovation. The conclusion is that South Africa’s construction industry could achieve sustainable development and growth as a result of SMME contractors whose competitiveness would have been measured through the use of the RoC tool. The main recommendation is that there be a clear understanding of competitiveness and what its benefits to the South African construction industry are whilst at the same time the RoC is acknowledged as the tool embedded with functionalities able to measure this competitiveness amongst graded contractors. The RoC would allow construction clients to not only measure contractor competitiveness but also that they may have an improved ability to measure the direct impacts of contractor development interventions. , Lolucubungulo lugxile ekubhekeni izimo ezinqala ngaphakathi komkhakha wezokwakha. Lubuka igalelo losonkontilaka abasebancane kulomkhakha ekuzithuthukiseni kanti futhi nemizamo eyenziwe uHulumeni endimeni edlalwe uhlu olushicilwelwe iBhodi yomkhakha wezokwakha (i-cidb). Umbhali walolucubungulo ukholelwa ekutheni loluhlu lungasetshenziswa hhayi kuphela ekuthuthikiseni ononkontilaka kodwa futhi ekwenzeni ukuthi bakhule kulo lona loluhlu baze bakwazi ukuthola amathuba angcono emisebenzi. Uhlu ekukhulunywa ngalo lapha lwashicilelwa i-cidb ngomgomo womthetho kaHulumeni we-Act 38 of 2000. Luyithuluzi elenzelwe ukuba likhulise umkhakha wezokwakha, lithuthukise osomabhizinisi abasebancane, likhuthaze imigomo efanelekile ekwakheni (improved delivery). Enye injongo yokushicilela lelithuluzi kwakuwukwenzela ukuthi kwaziwe inani labo osonkontilaka, ubulili babo nokuthi bagxile-phi ngokwezindawo zokusebenza. Konke loku kwakufanele ukuze uHulumeni kanye nabanye abaqashi bazi ukuthi uma kusikelwana ngemisebenzi bangaki na ononkontilaka abazokwazi ukufeza izidingo zemiphakathi esiphila kuyo? Lolucubungulo luzobheka ithuluzi elasungulwa umkhakha wokwakha ekutheni lingakwazi na ukudlondlobalisa osonkontilaka abasafufusa phakathi kwalemikhakha (grades) ababekwe kuyo? Kuzobhekwa futhi ubugugu balo lona lelithuluzi. Akuzoqxilwa kubo bonke osonkontilaka, kodwa kulabo abasabancane ngokwamabhizinisi abo ababekwe emazingeni kusukela ku-2 kuya ku-5 ngokoshicilelo le-cidb. Kuzobhekwa amakhono abo labosonkontilaka, kubhekwe futhi izinkomba ezingabadlondlobalisa ngokwamabhizinisi. Okunye okuhloswe yilolucubungulo ukubheka ukuthi umkhakha wezokwakha uyakwazi na ukukhiqiza amathuba anele isikhathi eside kwenzelwa osonkotilaka belu nokuthi uyakwazi na ukuqhubeka wakhe amathuba azokhuthaza ukukhula kwabo. Ekugcineni okufanele kufezwe yilolucubungulo wukuthi uhlu olushicilelwe losonkontilaka lungasiza ekukhuthazeni udlondlobalo losonkontilaka abancane.
- Full Text:
- Date Issued: 2012
Optimised small scale reative compensation for Eskom's Albany-Wesley 66/22Kv transmission system
- Authors: Ndimurwimo, Alexis
- Date: 2012
- Subjects: Capacitors , Electric capacity , Power transmission , Voltage regulators
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9597 , http://hdl.handle.net/10948/d1008156 , Capacitors , Electric capacity , Power transmission , Voltage regulators
- Description: Reactive power compensation, as generated by capacitors, has been used to mitigate the constraints of power transmission and improve the power transfer of the transmission system of the South African power utility, Eskom‟s 66/22kV Albany-Wesley transmission system. An investigation was carried out on a number of current compensation schemes, and their operations, by means of load flow analysis. Different capacitor qualities and technologies were applied to alter the transmission line characteristics that resulted in acceptable voltage regulation. This resulted in easing the load on the lines and transformers and hence reducing line losses. For long transmission lines, utilities need voltage support, as provided for by different voltage compensators, to keep the terminal voltage within standard voltage regulation, and meet the designed power demand. The approach to large and small scale compensation was tested and the outcomes revealed distinct patterns that were used to confirm the hypothesis and improve the transfer of power. The templating temperature and thermal perspective as used by Eskom on line design was discussed and used to design a new transmission line. Load flow solutions were also used to plan and design the optimised transmission system as well as to determine the specification and location of the compensating capacitor banks. Capacitor banks, as a source of reactive power, were used to model the compensation in this research. Electrical protection and faults associated with the capacitors banks were discussed, as prevention to total blackout or load shedding on the transmission line in case of established contingency. Long term investment plans, to meet future electricity demands, require substantial investment hence a financial survey was carried out. Finally this dissertation selects a viable solution to meet the electrical power demands and then recommends a way forward for the Eskom‟s 66/22kV Albany-Wesley line.
- Full Text:
- Date Issued: 2012
- Authors: Ndimurwimo, Alexis
- Date: 2012
- Subjects: Capacitors , Electric capacity , Power transmission , Voltage regulators
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9597 , http://hdl.handle.net/10948/d1008156 , Capacitors , Electric capacity , Power transmission , Voltage regulators
- Description: Reactive power compensation, as generated by capacitors, has been used to mitigate the constraints of power transmission and improve the power transfer of the transmission system of the South African power utility, Eskom‟s 66/22kV Albany-Wesley transmission system. An investigation was carried out on a number of current compensation schemes, and their operations, by means of load flow analysis. Different capacitor qualities and technologies were applied to alter the transmission line characteristics that resulted in acceptable voltage regulation. This resulted in easing the load on the lines and transformers and hence reducing line losses. For long transmission lines, utilities need voltage support, as provided for by different voltage compensators, to keep the terminal voltage within standard voltage regulation, and meet the designed power demand. The approach to large and small scale compensation was tested and the outcomes revealed distinct patterns that were used to confirm the hypothesis and improve the transfer of power. The templating temperature and thermal perspective as used by Eskom on line design was discussed and used to design a new transmission line. Load flow solutions were also used to plan and design the optimised transmission system as well as to determine the specification and location of the compensating capacitor banks. Capacitor banks, as a source of reactive power, were used to model the compensation in this research. Electrical protection and faults associated with the capacitors banks were discussed, as prevention to total blackout or load shedding on the transmission line in case of established contingency. Long term investment plans, to meet future electricity demands, require substantial investment hence a financial survey was carried out. Finally this dissertation selects a viable solution to meet the electrical power demands and then recommends a way forward for the Eskom‟s 66/22kV Albany-Wesley line.
- Full Text:
- Date Issued: 2012
Post occupancy evaluation of an office building : the case of country club estate, Johannesburg
- Matshili, Humbulani Emmanuel
- Authors: Matshili, Humbulani Emmanuel
- Date: 2012
- Subjects: Architectural design -- Evaluation , Offices -- Design , Office buildings -- South Africa -- Johannesburg -- Evaluation , Real property -- South Africa -- Johannesburg
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9703 , http://hdl.handle.net/10948/d1018554
- Description: Most organisations nowadays want to build offices that are cost effective, but at the same time they forget to consider the impact of IEQ on the occupants’ wellbeing and performance. These offices are equipped with air-conditioners, which may impact negatively on performances if not monitored, controlled and maintained. An occupant’s performance may be accelerated or reduced, based on the effectiveness of IEQ in the office buildings. It is imperative that the employer or management create a work environment that is conducive to the occupants’ needs, so that the occupants may be able to improve their work performance that often yields increased productivity. The main aim of the study was to investigate the efficiency of a building’s Indoor Environmental Quality (IEQ) and how it affects workers with regard to productivity. The objectives of the study were: to determine the level of satisfaction of the occupants in terms of the IEQ, evaluate the effects that the current IEQ of the building has on the productivity of the occupants, and proffer solutions to identified problems so that the building performance can be improved, and similar future buildings can be improved upon in terms of IEQ. Post Occupancy Evaluation (POE) was utilised to conduct the evaluation. This will help stakeholders and managements to ensure that past mistakes committed are not repeated in the future buildings. POE analyses IEQ related to Indoor Air Quality (IEQ), thermal comfort, occupant’s satisfaction and occupant performance and productivity. There is a correlation between different indoor parameters of the occupants’ satisfaction, health and productivity at the workplace. For these correlations to complement each other successfully, IEQ factors must be conducive to human wellbeing. Workplace environments are perceived as unsafe and unhygienic. This situation is caused by poor planning of workstations, low indoor air quality, inappropriate lighting in the office, lack of ventilation and insufficient safety measures. In particular, findings of this study demonstrate the low level of occupants’ satisfaction with regard to office buildings in the Country Club Estate, Johannesburg. The results from this study show that POE is perceived to be completely new to occupants of the Country Club Estate. Management or stakeholders have a huge task ahead to address the benefits of implementing POE and to face the consequences if POE is not implemented.
- Full Text:
- Date Issued: 2012
- Authors: Matshili, Humbulani Emmanuel
- Date: 2012
- Subjects: Architectural design -- Evaluation , Offices -- Design , Office buildings -- South Africa -- Johannesburg -- Evaluation , Real property -- South Africa -- Johannesburg
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9703 , http://hdl.handle.net/10948/d1018554
- Description: Most organisations nowadays want to build offices that are cost effective, but at the same time they forget to consider the impact of IEQ on the occupants’ wellbeing and performance. These offices are equipped with air-conditioners, which may impact negatively on performances if not monitored, controlled and maintained. An occupant’s performance may be accelerated or reduced, based on the effectiveness of IEQ in the office buildings. It is imperative that the employer or management create a work environment that is conducive to the occupants’ needs, so that the occupants may be able to improve their work performance that often yields increased productivity. The main aim of the study was to investigate the efficiency of a building’s Indoor Environmental Quality (IEQ) and how it affects workers with regard to productivity. The objectives of the study were: to determine the level of satisfaction of the occupants in terms of the IEQ, evaluate the effects that the current IEQ of the building has on the productivity of the occupants, and proffer solutions to identified problems so that the building performance can be improved, and similar future buildings can be improved upon in terms of IEQ. Post Occupancy Evaluation (POE) was utilised to conduct the evaluation. This will help stakeholders and managements to ensure that past mistakes committed are not repeated in the future buildings. POE analyses IEQ related to Indoor Air Quality (IEQ), thermal comfort, occupant’s satisfaction and occupant performance and productivity. There is a correlation between different indoor parameters of the occupants’ satisfaction, health and productivity at the workplace. For these correlations to complement each other successfully, IEQ factors must be conducive to human wellbeing. Workplace environments are perceived as unsafe and unhygienic. This situation is caused by poor planning of workstations, low indoor air quality, inappropriate lighting in the office, lack of ventilation and insufficient safety measures. In particular, findings of this study demonstrate the low level of occupants’ satisfaction with regard to office buildings in the Country Club Estate, Johannesburg. The results from this study show that POE is perceived to be completely new to occupants of the Country Club Estate. Management or stakeholders have a huge task ahead to address the benefits of implementing POE and to face the consequences if POE is not implemented.
- Full Text:
- Date Issued: 2012
Shape memory Alloy Actuator for cross-feed in turning operation
- Authors: Otieno, Timothy
- Date: 2012
- Subjects: Shape memory alloys -- Mechanical properties , Shape memory alloys , Intermetallic compounds , Materials -- Mechanical properties
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9650 , http://hdl.handle.net/10948/d1012590 , Shape memory alloys -- Mechanical properties , Shape memory alloys , Intermetallic compounds , Materials -- Mechanical properties
- Description: A shape memory alloy (SMA) is an intermetallic compound able to recover, in a continuous and reversible way, a predetermined shape during a thermal cycle while generating mechanical work. In this thesis, its use in developing an actuator for a machining process is investigated. The actuator is to drive the tool cross feed into an aluminium workpiece in a finishing lathe operation. The actuator structure was designed with an output shaft to transfer the movement and force of the SMA wire outside the device. The actuator was fabricated and the experimental setup was assembled which also included a power supply control circuit, displacement sensor, temperature sensor and current sensor for feedback, and data collection and monitoring within software. PID control was implemented within the software that regulated the power supplied to the SMA, thereby providing the position control. This study covers the mechatronics system design and development of the actuator, the experiments carried out to determine performance and the results. Open loop tests were conducted to determine the maximum stroke, the effect of cooling and response to radial forces. These tests revealed the expected non-linearity of the SMA. The actuator achieved the rated maximum stroke of 3-4 percent. The forced cooling test showed a general improvement of approximately 65 percent with fans. The radial force tests showed the value of the maximum stroke remained unaffected by force. The results from the closed loop tests responses with a tuned PID controller produced a stable system for various displacement setpoints. The actuator had a feed rate of 0.25 mm/s and an accuracy of 0.0153mm, which was within the acceptable accuracy for turning operations. The system was deemed accurate for a conventional lathe machine cross feed.
- Full Text:
- Date Issued: 2012
- Authors: Otieno, Timothy
- Date: 2012
- Subjects: Shape memory alloys -- Mechanical properties , Shape memory alloys , Intermetallic compounds , Materials -- Mechanical properties
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9650 , http://hdl.handle.net/10948/d1012590 , Shape memory alloys -- Mechanical properties , Shape memory alloys , Intermetallic compounds , Materials -- Mechanical properties
- Description: A shape memory alloy (SMA) is an intermetallic compound able to recover, in a continuous and reversible way, a predetermined shape during a thermal cycle while generating mechanical work. In this thesis, its use in developing an actuator for a machining process is investigated. The actuator is to drive the tool cross feed into an aluminium workpiece in a finishing lathe operation. The actuator structure was designed with an output shaft to transfer the movement and force of the SMA wire outside the device. The actuator was fabricated and the experimental setup was assembled which also included a power supply control circuit, displacement sensor, temperature sensor and current sensor for feedback, and data collection and monitoring within software. PID control was implemented within the software that regulated the power supplied to the SMA, thereby providing the position control. This study covers the mechatronics system design and development of the actuator, the experiments carried out to determine performance and the results. Open loop tests were conducted to determine the maximum stroke, the effect of cooling and response to radial forces. These tests revealed the expected non-linearity of the SMA. The actuator achieved the rated maximum stroke of 3-4 percent. The forced cooling test showed a general improvement of approximately 65 percent with fans. The radial force tests showed the value of the maximum stroke remained unaffected by force. The results from the closed loop tests responses with a tuned PID controller produced a stable system for various displacement setpoints. The actuator had a feed rate of 0.25 mm/s and an accuracy of 0.0153mm, which was within the acceptable accuracy for turning operations. The system was deemed accurate for a conventional lathe machine cross feed.
- Full Text:
- Date Issued: 2012
Strategies for sustainable housing co-operatives in South Africa
- Authors: Jimoh, Richard Ajayi
- Date: 2012
- Subjects: Housing, Cooperative -- South Africa , Housing -- South Africa , Sustainable development -- South Africa , Housing -- Finance-- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9690 , http://hdl.handle.net/10948/d1009500 , Housing, Cooperative -- South Africa , Housing -- South Africa , Sustainable development -- South Africa , Housing -- Finance-- South Africa
- Description: An increasing number of people are in need of housing that would improve long-term tenure for them. Private ownership is a well-known incentive for peoples’ participation in housing programmes. The current difficulties in obtaining credit for housing, following the global economic crisis, show that private individual home-ownership is not effective enough in addressing the housing needs of the low and middle income groups. As a result of this, the need to find an option that will solve the housing needs of the people became intense. However, the implementation of the co-operative housing delivery option in South Africa has not been successfully implemented as a result of the actions or the inactions of the role players. The study sought answer to the causes of the inability to successfully implement the co-operative housing approach through the use of ‘triad model’ that has to do with the ideology of co-operatives, the praxis and the organisational structures of the various housing co-operatives. The study was domiciled in a pragmatic paradigm, using the mixed methods research approach by conducting a three-stage research whereby convergent parallel design was adopted as the methodology. Questionnaires were administered to the chairpersons of the housing co-operatives identified in this stage one of the study. Stage two consisted of conducting interviews with chairpersons of six housing co-operatives using the purposive non-probability sampling method. The final stage was the survey among the members of the housing co-operatives interviewed. It was discovered, inter alia, that the membership of housing co-operatives was not voluntary; policy and legislative documents on social housing were biased against the co-operative housing approach; limited understanding of the co-operative approach exists among officials of government responsible for the implementations and a lack of training to members of the housing co-operatives by agencies of government responsible for propagating the approach was evident. Based on the findings, framework for sustainable housing co-operatives in South Africa was proposed from the strategies identified. The strategies identified were classified into the following factors: Policy and legislation; support services; education, training and information; and governance.
- Full Text:
- Date Issued: 2012
- Authors: Jimoh, Richard Ajayi
- Date: 2012
- Subjects: Housing, Cooperative -- South Africa , Housing -- South Africa , Sustainable development -- South Africa , Housing -- Finance-- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9690 , http://hdl.handle.net/10948/d1009500 , Housing, Cooperative -- South Africa , Housing -- South Africa , Sustainable development -- South Africa , Housing -- Finance-- South Africa
- Description: An increasing number of people are in need of housing that would improve long-term tenure for them. Private ownership is a well-known incentive for peoples’ participation in housing programmes. The current difficulties in obtaining credit for housing, following the global economic crisis, show that private individual home-ownership is not effective enough in addressing the housing needs of the low and middle income groups. As a result of this, the need to find an option that will solve the housing needs of the people became intense. However, the implementation of the co-operative housing delivery option in South Africa has not been successfully implemented as a result of the actions or the inactions of the role players. The study sought answer to the causes of the inability to successfully implement the co-operative housing approach through the use of ‘triad model’ that has to do with the ideology of co-operatives, the praxis and the organisational structures of the various housing co-operatives. The study was domiciled in a pragmatic paradigm, using the mixed methods research approach by conducting a three-stage research whereby convergent parallel design was adopted as the methodology. Questionnaires were administered to the chairpersons of the housing co-operatives identified in this stage one of the study. Stage two consisted of conducting interviews with chairpersons of six housing co-operatives using the purposive non-probability sampling method. The final stage was the survey among the members of the housing co-operatives interviewed. It was discovered, inter alia, that the membership of housing co-operatives was not voluntary; policy and legislative documents on social housing were biased against the co-operative housing approach; limited understanding of the co-operative approach exists among officials of government responsible for the implementations and a lack of training to members of the housing co-operatives by agencies of government responsible for propagating the approach was evident. Based on the findings, framework for sustainable housing co-operatives in South Africa was proposed from the strategies identified. The strategies identified were classified into the following factors: Policy and legislation; support services; education, training and information; and governance.
- Full Text:
- Date Issued: 2012
The development of a programmable engine management system for a formula student race vehicle
- Authors: Parmar, Hiten
- Date: 2012
- Subjects: Automobiles -- Motors -- Computer control systems , Automotive computers
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9601 , http://hdl.handle.net/10948/d1010957 , Automobiles -- Motors -- Computer control systems , Automotive computers
- Full Text:
- Date Issued: 2012
- Authors: Parmar, Hiten
- Date: 2012
- Subjects: Automobiles -- Motors -- Computer control systems , Automotive computers
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9601 , http://hdl.handle.net/10948/d1010957 , Automobiles -- Motors -- Computer control systems , Automotive computers
- Full Text:
- Date Issued: 2012
The development of an optimised rotor software design tool to improve performance of small horizontal axis wind turbines
- Authors: Newey, Kerryn Brett
- Date: 2012
- Subjects: Wind turbines -- Design , Wind power , Turbines -- Design
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9620 , http://hdl.handle.net/10948/d1009431 , Wind turbines -- Design , Wind power , Turbines -- Design
- Description: Horizontal axis wind turbines are by far the most common and well understood forms of wind turbine. Typically a large amount of research and development has been invested in the technology of large scale wind turbines. Unfortunately, development of small machines (rotor diameter smaller than 10 metres) has not been as forthcoming. The advantages of small turbines are that they are accessible to the individual consumer and they are a very attractive project for the home builder. The disadvantage of small turbines is that due to the negative influence of economies of scale, they tend to be costly in relation to their power output and suffer from a long-term return on investment. Furthermore, trends in the wind industry have shown that smaller machines tend to be relatively simple devices that have been developed with very little research and development. As a result, small turbines can be inefficient, unreliable and expensive to maintain. In many cases rotor design is less than optimal, with very little blade refinement. This is especially critical for small rotors due to low Reynolds Number operation. Further exacerbating the problem is that the rotors are typically not well matched to the generator. In many cases the machines are not suited to the wind speed range in which they are designed to operate, reducing the financial viability due to poor performance. It is envisaged that by applying optimising techniques and automating some of the design complexities into a software design tool, more cost-effective and viable machines can be developed that will deliver improved performance and therefore become more financially viable.
- Full Text:
- Date Issued: 2012
- Authors: Newey, Kerryn Brett
- Date: 2012
- Subjects: Wind turbines -- Design , Wind power , Turbines -- Design
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9620 , http://hdl.handle.net/10948/d1009431 , Wind turbines -- Design , Wind power , Turbines -- Design
- Description: Horizontal axis wind turbines are by far the most common and well understood forms of wind turbine. Typically a large amount of research and development has been invested in the technology of large scale wind turbines. Unfortunately, development of small machines (rotor diameter smaller than 10 metres) has not been as forthcoming. The advantages of small turbines are that they are accessible to the individual consumer and they are a very attractive project for the home builder. The disadvantage of small turbines is that due to the negative influence of economies of scale, they tend to be costly in relation to their power output and suffer from a long-term return on investment. Furthermore, trends in the wind industry have shown that smaller machines tend to be relatively simple devices that have been developed with very little research and development. As a result, small turbines can be inefficient, unreliable and expensive to maintain. In many cases rotor design is less than optimal, with very little blade refinement. This is especially critical for small rotors due to low Reynolds Number operation. Further exacerbating the problem is that the rotors are typically not well matched to the generator. In many cases the machines are not suited to the wind speed range in which they are designed to operate, reducing the financial viability due to poor performance. It is envisaged that by applying optimising techniques and automating some of the design complexities into a software design tool, more cost-effective and viable machines can be developed that will deliver improved performance and therefore become more financially viable.
- Full Text:
- Date Issued: 2012