Implementation of local agenda 21's education, awareness and training component: a case study of Gaborone
- Authors: Mogotsi, Barulaganye Jones
- Date: 2006
- Subjects: Environmental education -- Botswana -- Gabarone -- Case studies Environmental education -- Activity programs Environmental health -- Botswana -- Gabarone -- Case studies Sustainable development -- Botswana Environmental policy -- International cooperation Environmental protection -- Botswana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1565 , http://hdl.handle.net/10962/d1003447
- Description: ‘What is required is the ‘politics of the rhizome’ in which everyone, every community, every nation and every major region comes to terms with the uniqueness of their situation and acts accordingly – and realises that it is only by vast numbers of people, of groups and organizations acting in accordance with possibilities of their situations, that the environmental crisis will be solved.’ (Gare, 1995:161). The study investigates the implementation of Local Agenda 21’s education, awareness and training component by the Gaborone City Council Environmental Health Department (GCCEHD) to address environmental challenges facing the city of Gaborone, the capital city of Botswana. The research was conducted as a qualitative case study that made use of semi-structured interviews, focus group interviews and document analysis as instruments of data generation. Samples of respondents were selected from the Gaborone City Council (GCCEHD) employees in management positions, workers, and elected political councillors. The study is contextualised through establishing environmental issues in the Gaborone City Council, identifying strategies to address environmental issues and the review of the Waste Management Plan 2003-2009, which the department uses as a guiding document for waste management. The study establishes that the council employees are mostly concerned with issues of waste management and need commitment from all Local Government sectors of the work force. The study established the importance of education, awareness and training as a response to environmental issues facing Gaborone. The study also establishes the need for social education in terms of public education, awareness and training needed for the public to adequately respond to environmental challenges in their context. Models and relevant policy and guiding documents such as the Vision for Greater Gaborone, DPSEEA Model and Botswana Environmental Planning Principles were identified and recommended for the department to consider. The awareness and training activities should be developed and involve the community in environmental management. This should enable the council to create opportunities for income generation, at the same time changing community negative attitudes towards the environment and improving service delivery by the department.
- Full Text:
- Authors: Mogotsi, Barulaganye Jones
- Date: 2006
- Subjects: Environmental education -- Botswana -- Gabarone -- Case studies Environmental education -- Activity programs Environmental health -- Botswana -- Gabarone -- Case studies Sustainable development -- Botswana Environmental policy -- International cooperation Environmental protection -- Botswana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1565 , http://hdl.handle.net/10962/d1003447
- Description: ‘What is required is the ‘politics of the rhizome’ in which everyone, every community, every nation and every major region comes to terms with the uniqueness of their situation and acts accordingly – and realises that it is only by vast numbers of people, of groups and organizations acting in accordance with possibilities of their situations, that the environmental crisis will be solved.’ (Gare, 1995:161). The study investigates the implementation of Local Agenda 21’s education, awareness and training component by the Gaborone City Council Environmental Health Department (GCCEHD) to address environmental challenges facing the city of Gaborone, the capital city of Botswana. The research was conducted as a qualitative case study that made use of semi-structured interviews, focus group interviews and document analysis as instruments of data generation. Samples of respondents were selected from the Gaborone City Council (GCCEHD) employees in management positions, workers, and elected political councillors. The study is contextualised through establishing environmental issues in the Gaborone City Council, identifying strategies to address environmental issues and the review of the Waste Management Plan 2003-2009, which the department uses as a guiding document for waste management. The study establishes that the council employees are mostly concerned with issues of waste management and need commitment from all Local Government sectors of the work force. The study established the importance of education, awareness and training as a response to environmental issues facing Gaborone. The study also establishes the need for social education in terms of public education, awareness and training needed for the public to adequately respond to environmental challenges in their context. Models and relevant policy and guiding documents such as the Vision for Greater Gaborone, DPSEEA Model and Botswana Environmental Planning Principles were identified and recommended for the department to consider. The awareness and training activities should be developed and involve the community in environmental management. This should enable the council to create opportunities for income generation, at the same time changing community negative attitudes towards the environment and improving service delivery by the department.
- Full Text:
Implementing performance management at local government level in South Africa : a case study on the impact of organisational culture
- Authors: Williams, Quinton Walter
- Date: 2006
- Subjects: Buffalo City (South Africa) Local government -- South Africa Municipal government -- South Africa Performance -- Management -- South Africa Corporate culture -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:749 , http://hdl.handle.net/10962/d1003870
- Description: Local Government in South Africa has undergone much transformation since 2000. Although much of the change has been to correct imbalances, inequities and disparities within our local communities as a result of Apartheid, change has also been motivated by National Government’s realisation that, as with governments throughout the world, there is a need to modernise all spheres of Government. Part of this transformation process at a local government level in South Africa has been to ensure that municipalities become more responsive to the communities’ needs. The guiding principles for this transformation are contained in the White Paper on the Transformation of the Public Service (1995) and the Batho Pele White Paper (1997). This has informed the Municipal Systems Act: Act 32 of 2000 of which Chapter 6 determines that municipalities will have a performance management system to promote a culture of performance management amongst the political structures, political office bearers, councillors and administration. The performance management system must ensure that the municipality administers its affairs in an economical, effective, efficient and accountable manner. A literature review contained in this research, indicates that internationally, implementing performance management systems at a local government level is impact upon by a number of factors such as the organizational culture of an institution. This research, which has been grounded within a constructivist paradigm, describes the impact organizational culture has had on the implementation process of the performance management system at Buffalo City Municipality. Interviews were conducted amongst the Section 57 employees (i.e. the Directors) and those employees directly responsible for implementing performance management. The four Directors, two General Managers and the portfolio councilor were interviewed. Semi-structured interviews were conducted with the interviewees and this culminated in a total of 10 hours of interviewing. The protocols were analyzed using the guidelines suggested by Boyatzis (1998) and the findings are detailed in two chapters. The findings of the research were that the implementation of the performance management system at Buffalo City Municipality has been impacted on by the dichotomy between the political and administrative leadership, resulting in non-implementation of council resolutions, the lack of an organizational strategy, poor institutional arrangements and inadequate resource allocation, are reported. However, the most important finding was the impact that a culture of fear has had on the implementation process. This culture of fear and its impact on the implementation of performance management system is described as the most pervasive and insidious of all the findings to have negatively impacted on the implementation process. This research ends with recommendations for further research and it is argued that each organization has its own unique organizational culture. The conclusion is that no single typology, as contained in the literature, which can account for the specific impact organizational culture will have on the implementation process of a performance management system at local government level in South Africa. Consequently, implementers of performance management systems must assess the unique characteristics of each organization’s culture prior to implementation, in order to evaluate its impact that the organizational culture can have on the process.
- Full Text:
- Authors: Williams, Quinton Walter
- Date: 2006
- Subjects: Buffalo City (South Africa) Local government -- South Africa Municipal government -- South Africa Performance -- Management -- South Africa Corporate culture -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:749 , http://hdl.handle.net/10962/d1003870
- Description: Local Government in South Africa has undergone much transformation since 2000. Although much of the change has been to correct imbalances, inequities and disparities within our local communities as a result of Apartheid, change has also been motivated by National Government’s realisation that, as with governments throughout the world, there is a need to modernise all spheres of Government. Part of this transformation process at a local government level in South Africa has been to ensure that municipalities become more responsive to the communities’ needs. The guiding principles for this transformation are contained in the White Paper on the Transformation of the Public Service (1995) and the Batho Pele White Paper (1997). This has informed the Municipal Systems Act: Act 32 of 2000 of which Chapter 6 determines that municipalities will have a performance management system to promote a culture of performance management amongst the political structures, political office bearers, councillors and administration. The performance management system must ensure that the municipality administers its affairs in an economical, effective, efficient and accountable manner. A literature review contained in this research, indicates that internationally, implementing performance management systems at a local government level is impact upon by a number of factors such as the organizational culture of an institution. This research, which has been grounded within a constructivist paradigm, describes the impact organizational culture has had on the implementation process of the performance management system at Buffalo City Municipality. Interviews were conducted amongst the Section 57 employees (i.e. the Directors) and those employees directly responsible for implementing performance management. The four Directors, two General Managers and the portfolio councilor were interviewed. Semi-structured interviews were conducted with the interviewees and this culminated in a total of 10 hours of interviewing. The protocols were analyzed using the guidelines suggested by Boyatzis (1998) and the findings are detailed in two chapters. The findings of the research were that the implementation of the performance management system at Buffalo City Municipality has been impacted on by the dichotomy between the political and administrative leadership, resulting in non-implementation of council resolutions, the lack of an organizational strategy, poor institutional arrangements and inadequate resource allocation, are reported. However, the most important finding was the impact that a culture of fear has had on the implementation process. This culture of fear and its impact on the implementation of performance management system is described as the most pervasive and insidious of all the findings to have negatively impacted on the implementation process. This research ends with recommendations for further research and it is argued that each organization has its own unique organizational culture. The conclusion is that no single typology, as contained in the literature, which can account for the specific impact organizational culture will have on the implementation process of a performance management system at local government level in South Africa. Consequently, implementers of performance management systems must assess the unique characteristics of each organization’s culture prior to implementation, in order to evaluate its impact that the organizational culture can have on the process.
- Full Text:
Implementing the GrabCut segmentation technique as a plugin for the GIMP
- Marsh, Matthew, Bangay, Shaun D, Lobb, Adele
- Authors: Marsh, Matthew , Bangay, Shaun D , Lobb, Adele
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433207 , vital:72951 , https://doi.org/10.1145/1108590.1108618
- Description: Image segmentation requires a segmentation tool that is fast and easy to use. The GIMP has built in segmentation tools, but under some circumstances these tools perform badly. "GrabCut" is an innovative segmentation technique that uses both region and boundary information in order to perform segmentation. Several variations on the "GrabCut" algorithm have been implemented as a plugin for the GIMP. The results obtained using "GrabCut" are comparable, and often better than the results of all the other built in segmentation tools.
- Full Text:
- Authors: Marsh, Matthew , Bangay, Shaun D , Lobb, Adele
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433207 , vital:72951 , https://doi.org/10.1145/1108590.1108618
- Description: Image segmentation requires a segmentation tool that is fast and easy to use. The GIMP has built in segmentation tools, but under some circumstances these tools perform badly. "GrabCut" is an innovative segmentation technique that uses both region and boundary information in order to perform segmentation. Several variations on the "GrabCut" algorithm have been implemented as a plugin for the GIMP. The results obtained using "GrabCut" are comparable, and often better than the results of all the other built in segmentation tools.
- Full Text:
Improving the bioremediation of phenolic wastewaters by Trametes versicolor
- Ryan, D, Leukes, Winston D, Burton, Stephanie G
- Authors: Ryan, D , Leukes, Winston D , Burton, Stephanie G
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6467 , http://hdl.handle.net/10962/d1005796 , http://dx.doi.org/10.1016/j.biortech.2006.02.001
- Description: The successful bioremediation of a phenolic wastewater by Trametes versicolor was found to be dependent on a range of factors including: fungal growth, culture age and activity and enzyme (laccase) production. These aspects were enhanced by the optimisation of the growth medium used and time of addition of the pollutant to the fungal cultures. Different media containing ‘high’ (20 g/L), ‘low’ (2 g/L) and ‘sufficient’ (10 g/L) concentrations of carbon and nitrogen sources were investigated. The medium containing both glucose and peptone at 10 g/L resulted in the highest Growth Related Productivity (the product of specific yield and μ) of laccase (1.46 Units of laccase activity)/gram biomass/day and was used in all further experiments. The use of the guaiacol as an inducer further increased laccase activity 780% without inhibiting growth; similarly the phenolic effluent studied boosted activity almost 5 times. The timing of the addition of the phenolic effluent was found to have important consequences in its removal and at least 8 days of prior growth was required. Under these conditions, 0.125 g phenol/g biomass and 0.231 g o-cresol/g biomass were removed from solution per day.
- Full Text:
- Authors: Ryan, D , Leukes, Winston D , Burton, Stephanie G
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6467 , http://hdl.handle.net/10962/d1005796 , http://dx.doi.org/10.1016/j.biortech.2006.02.001
- Description: The successful bioremediation of a phenolic wastewater by Trametes versicolor was found to be dependent on a range of factors including: fungal growth, culture age and activity and enzyme (laccase) production. These aspects were enhanced by the optimisation of the growth medium used and time of addition of the pollutant to the fungal cultures. Different media containing ‘high’ (20 g/L), ‘low’ (2 g/L) and ‘sufficient’ (10 g/L) concentrations of carbon and nitrogen sources were investigated. The medium containing both glucose and peptone at 10 g/L resulted in the highest Growth Related Productivity (the product of specific yield and μ) of laccase (1.46 Units of laccase activity)/gram biomass/day and was used in all further experiments. The use of the guaiacol as an inducer further increased laccase activity 780% without inhibiting growth; similarly the phenolic effluent studied boosted activity almost 5 times. The timing of the addition of the phenolic effluent was found to have important consequences in its removal and at least 8 days of prior growth was required. Under these conditions, 0.125 g phenol/g biomass and 0.231 g o-cresol/g biomass were removed from solution per day.
- Full Text:
In search of optimal stocking regimes in semi-arid grazing lands : one size does not fit all
- Campbell, Bruce M, Gordon, Iain J, Luckert, Martin K, Petheram, Lisa, Vetter, Susan M
- Authors: Campbell, Bruce M , Gordon, Iain J , Luckert, Martin K , Petheram, Lisa , Vetter, Susan M
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6507 , http://hdl.handle.net/10962/d1005934
- Description: We discuss the search for optimal stocking regimes in semi-arid grazing lands. We argue that ‘one size does not fit all’ and that different stocking regimes are appropriate under different conditions. This paper is an attempt to move beyond polarization of the current debate towards a more integrative and flexible approach to grazing management. We propose five different conditions as major influences on grazing regimes: environmental variability and predictability; degradation and thresholds; property right regimes; discount rates; and market stability and prices. We suggest a lack of connection between the micro-economics literature and natural science and social-anthropological literature. It is timely to achieve greater integration around some key questions and hypotheses, and recognize that policy prescriptions at national or even regional levels are likely to have limited value due to context specificity.
- Full Text:
- Authors: Campbell, Bruce M , Gordon, Iain J , Luckert, Martin K , Petheram, Lisa , Vetter, Susan M
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6507 , http://hdl.handle.net/10962/d1005934
- Description: We discuss the search for optimal stocking regimes in semi-arid grazing lands. We argue that ‘one size does not fit all’ and that different stocking regimes are appropriate under different conditions. This paper is an attempt to move beyond polarization of the current debate towards a more integrative and flexible approach to grazing management. We propose five different conditions as major influences on grazing regimes: environmental variability and predictability; degradation and thresholds; property right regimes; discount rates; and market stability and prices. We suggest a lack of connection between the micro-economics literature and natural science and social-anthropological literature. It is timely to achieve greater integration around some key questions and hypotheses, and recognize that policy prescriptions at national or even regional levels are likely to have limited value due to context specificity.
- Full Text:
Incorporating fishermen’s local knowledge and behavior into geographical information systems (GIS) for designing marine protected areas in Oceania
- Shankar, Aswani, Lauer, Matthew
- Authors: Shankar, Aswani , Lauer, Matthew
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439109 , vital:73545 , xlink:href="https://doi.org/10.17730/humo.65.1.4y2q0vhe4l30n0uj"
- Description: Drawing on our experience in establishing marine protected areas (MPAs) in the Roviana and Vonavona Lagoons, New Georgia, Solomon Islands, this paper shows how a geographical information system (GIS) database can be used to incorporate sociospatial information, such as indigenous knowledge and artisanal fishing data, along with biophysical and other information to assist in MPA design. We argue that converting peoples’ knowledge and socioecological behavior into geo-spatial data allows researchers to formulate hypotheses regarding human responses to inter- and intra-habitat variability, along with other marine ecological processes, and help in the designing and implementation of resource management strategies in a cost-effective and participatory way, bridging the gap between indigenous and Western cognitions of seascapes. More generally, we show the significance of combining spatial tools, anthropological fieldwork, and social and natural science methods for studying artisanal fisheries with the goal of aiding the design of marine protected areas.
- Full Text:
- Authors: Shankar, Aswani , Lauer, Matthew
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439109 , vital:73545 , xlink:href="https://doi.org/10.17730/humo.65.1.4y2q0vhe4l30n0uj"
- Description: Drawing on our experience in establishing marine protected areas (MPAs) in the Roviana and Vonavona Lagoons, New Georgia, Solomon Islands, this paper shows how a geographical information system (GIS) database can be used to incorporate sociospatial information, such as indigenous knowledge and artisanal fishing data, along with biophysical and other information to assist in MPA design. We argue that converting peoples’ knowledge and socioecological behavior into geo-spatial data allows researchers to formulate hypotheses regarding human responses to inter- and intra-habitat variability, along with other marine ecological processes, and help in the designing and implementation of resource management strategies in a cost-effective and participatory way, bridging the gap between indigenous and Western cognitions of seascapes. More generally, we show the significance of combining spatial tools, anthropological fieldwork, and social and natural science methods for studying artisanal fisheries with the goal of aiding the design of marine protected areas.
- Full Text:
Increasing convergence between the recognition of an intangible asset for financial accounting purposes and strategic management accounting and project management techniques
- Seyfert, W, Rosenberg, David, Stack, Elizabeth M
- Authors: Seyfert, W , Rosenberg, David , Stack, Elizabeth M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: Article
- Identifier: vital:6074 , http://hdl.handle.net/10962/d1003824 , http://dx.doi.org/10.1108/10222529200600012
- Description: New management techniques such as 'just-in-time', 'lean manufacturing' and 'Six Sigma' allow management accountants to shift their focus from the management and control of production processes to the management of strategic issues. This paradigm shift resulted from shorter product life cycles, due to technological advances and a more competitive business environment. Recent revisions to the International Accounting Standards which are particularly supportive of life cycle costing and project management are likely to increase the focus on strategic management accounting further. This article describes developments in management accounting and the recent convergence of financial reporting in terms of International Accounting Standards with strategic management accounting and project management techniques. Strategic management accounting (particularly life cycle costing) involves applying project management techniques and using the calculus of investment to manage the project as a whole. This contrasts with managing only costs and revenues during the manufacturing phase of a project. The article demonstrates that project management techniques and the calculus of investment provide the information needed to account for the value of a project in terms of IAS 38: Intangible Assets. This will ultimately give rise to both improved decision-making and more relevant financial reporting.
- Full Text:
- Authors: Seyfert, W , Rosenberg, David , Stack, Elizabeth M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: Article
- Identifier: vital:6074 , http://hdl.handle.net/10962/d1003824 , http://dx.doi.org/10.1108/10222529200600012
- Description: New management techniques such as 'just-in-time', 'lean manufacturing' and 'Six Sigma' allow management accountants to shift their focus from the management and control of production processes to the management of strategic issues. This paradigm shift resulted from shorter product life cycles, due to technological advances and a more competitive business environment. Recent revisions to the International Accounting Standards which are particularly supportive of life cycle costing and project management are likely to increase the focus on strategic management accounting further. This article describes developments in management accounting and the recent convergence of financial reporting in terms of International Accounting Standards with strategic management accounting and project management techniques. Strategic management accounting (particularly life cycle costing) involves applying project management techniques and using the calculus of investment to manage the project as a whole. This contrasts with managing only costs and revenues during the manufacturing phase of a project. The article demonstrates that project management techniques and the calculus of investment provide the information needed to account for the value of a project in terms of IAS 38: Intangible Assets. This will ultimately give rise to both improved decision-making and more relevant financial reporting.
- Full Text:
Indigenous languages and the media in South Africa:
- Authors: Kaschula, Russell H
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175137 , vital:42546 , https://hdl.handle.net/10520/EJC15168
- Description: This article explores the status of South Africa’s indigenous languages and how they are being used in the media. More specifically, the performance of these languages in the print media, the broadcasting media and the Internet, is outlined. This is done against the backdrop of the South African Constitution, Section 6, which entrenches eleven official languages. Contrary to the Constitution’s provisions, it is found that the indigenous languages are achieving varying levels of success within the media. The reasons for this are outlined. Finally, the effects of globalisation on the indigenous languages within the media are assessed.
- Full Text:
- Authors: Kaschula, Russell H
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175137 , vital:42546 , https://hdl.handle.net/10520/EJC15168
- Description: This article explores the status of South Africa’s indigenous languages and how they are being used in the media. More specifically, the performance of these languages in the print media, the broadcasting media and the Internet, is outlined. This is done against the backdrop of the South African Constitution, Section 6, which entrenches eleven official languages. Contrary to the Constitution’s provisions, it is found that the indigenous languages are achieving varying levels of success within the media. The reasons for this are outlined. Finally, the effects of globalisation on the indigenous languages within the media are assessed.
- Full Text:
Inetvis, a visual tool for network telescope traffic analysis
- van Riel, Jean-Pierre, Irwin, Barry V W
- Authors: van Riel, Jean-Pierre , Irwin, Barry V W
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430176 , vital:72671 , https://doi.org/10.1145/1108590.1108604
- Description: This article illustrates the merits of visual analysis as it presents prelimi-nary findings using InetVis - an animated 3-D scatter plot visualization of network events. The concepts and features of InetVis are evaluated with reference to related work in the field. Tested against a network scanning tool, anticipated visual signs of port scanning and network mapping serve as a proof of concept. This research also unveils sub-stantial amounts of suspicious activity present in Internet traffic during August 2005, as captured by a class C network telescope. InetVis is found to have promising scalability whilst offering salient depictions of intrusive network activity.
- Full Text:
- Authors: van Riel, Jean-Pierre , Irwin, Barry V W
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430176 , vital:72671 , https://doi.org/10.1145/1108590.1108604
- Description: This article illustrates the merits of visual analysis as it presents prelimi-nary findings using InetVis - an animated 3-D scatter plot visualization of network events. The concepts and features of InetVis are evaluated with reference to related work in the field. Tested against a network scanning tool, anticipated visual signs of port scanning and network mapping serve as a proof of concept. This research also unveils sub-stantial amounts of suspicious activity present in Internet traffic during August 2005, as captured by a class C network telescope. InetVis is found to have promising scalability whilst offering salient depictions of intrusive network activity.
- Full Text:
Integrating Secure RTP into the Open Source VoIP PBX Asterisk
- Clayton, Bradley, Irwin, Barry V W, Terzoli, Alfredo
- Authors: Clayton, Bradley , Irwin, Barry V W , Terzoli, Alfredo
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428735 , vital:72532 , https://d1wqtxts1xzle7.cloudfront.net/84872934/66_Paper-libre.pdf?1650920302=response-content-disposi-tion=inline%3B+filename%3DIntegrating_Secure_RTP_into_the_Open_Sou.pdfExpires=1714744382Signature=PijjCGW0qcvkqRe-2R55HocKLvz9Ljw8jmhQvRQEi9YqJl7eWSiYnvs9CogY4u4bmDTYTLpvkA-nlfbiszg-s7Cq2nbLn3PUdfJ5cA11ujboi~i7oSoem7smuN1YCVZlg7FnZRd6mOXdTry9UAh8TlWyndF6pY1RXtc7bgb5cWeK4ggJ7~bM0HUXEbUKKa-abCZnGNrAZ59JIdL6CNx1Sht3o5mZTcyRL3PNVSOz17lldXi4FsAOEUwsVV-uv04hzp6pe6Qv5WbAP6tqk7deyoLUwk58A9F-PaJlOLy2gDAVLnbKT8RrxYg8tqv8SuBhPWb32CefBxv486N3F6izZw__Key-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: Implementations of Voice over Internet Protocol (VoIP) have focused, up to now, mainly on the need to transport data in real-time, often at the expense of security. The neglect of secure VoIP is often intentional, as developers are striving to minimise overheads and delays. The Secure Real-Time Protocol (SRTP) has the potential to secure real-time streams without exacting too high a performance price. SRTP is the addition of security to the audio/video profile used in the Real-Time Transport Protocol (RTP). SRTP adds confidentiality, integrity and op-tionaly authenticity to RTP media streams. This paper focuses on the integration of SRTP into Asterisk, an open-source VoIP PBX. SRTP support has recently been added to Asterisk by Mikael Magnusson. This paper analyses Magnusson’s implementation, contrasting it to a proof-of-concept implementation developed independently at Rhodes University. The interoperability of SRTP implementations cannot be taken for granted, given the relatively recent standardization of the pro-tocol, and so Magnusson’s implementation is tested against another SRTP implementation. Finally, the paper highlights a major shortcoming in Magnusson’s implementation, namely that the exchange of encryp-tion keys is done in the clear. It concludes by proposing possible solu-tions, such as TLS, IPSec and MIkey.
- Full Text:
- Authors: Clayton, Bradley , Irwin, Barry V W , Terzoli, Alfredo
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428735 , vital:72532 , https://d1wqtxts1xzle7.cloudfront.net/84872934/66_Paper-libre.pdf?1650920302=response-content-disposi-tion=inline%3B+filename%3DIntegrating_Secure_RTP_into_the_Open_Sou.pdfExpires=1714744382Signature=PijjCGW0qcvkqRe-2R55HocKLvz9Ljw8jmhQvRQEi9YqJl7eWSiYnvs9CogY4u4bmDTYTLpvkA-nlfbiszg-s7Cq2nbLn3PUdfJ5cA11ujboi~i7oSoem7smuN1YCVZlg7FnZRd6mOXdTry9UAh8TlWyndF6pY1RXtc7bgb5cWeK4ggJ7~bM0HUXEbUKKa-abCZnGNrAZ59JIdL6CNx1Sht3o5mZTcyRL3PNVSOz17lldXi4FsAOEUwsVV-uv04hzp6pe6Qv5WbAP6tqk7deyoLUwk58A9F-PaJlOLy2gDAVLnbKT8RrxYg8tqv8SuBhPWb32CefBxv486N3F6izZw__Key-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: Implementations of Voice over Internet Protocol (VoIP) have focused, up to now, mainly on the need to transport data in real-time, often at the expense of security. The neglect of secure VoIP is often intentional, as developers are striving to minimise overheads and delays. The Secure Real-Time Protocol (SRTP) has the potential to secure real-time streams without exacting too high a performance price. SRTP is the addition of security to the audio/video profile used in the Real-Time Transport Protocol (RTP). SRTP adds confidentiality, integrity and op-tionaly authenticity to RTP media streams. This paper focuses on the integration of SRTP into Asterisk, an open-source VoIP PBX. SRTP support has recently been added to Asterisk by Mikael Magnusson. This paper analyses Magnusson’s implementation, contrasting it to a proof-of-concept implementation developed independently at Rhodes University. The interoperability of SRTP implementations cannot be taken for granted, given the relatively recent standardization of the pro-tocol, and so Magnusson’s implementation is tested against another SRTP implementation. Finally, the paper highlights a major shortcoming in Magnusson’s implementation, namely that the exchange of encryp-tion keys is done in the clear. It concludes by proposing possible solu-tions, such as TLS, IPSec and MIkey.
- Full Text:
Intellectual achievement in pursuit of true belief
- Authors: Shapiro, Lucy Deborah
- Date: 2006 , 2013-06-14
- Subjects: Delusions , Knowledge, Theory of , Epistemics , Truth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2735 , http://hdl.handle.net/10962/d1005955 , Delusions , Knowledge, Theory of , Epistemics , Truth
- Description: The practice of inquiry, in which we seek and pursue true beliefs by forming justified beliefs, is important to us. This thesis will address two questions concerning the significance of this practice. These are the question of what explains our preference for this particular belief-forming practice, and whether this value can be explained by the value of true belief alone. To answer these questions I will examme a variety of our intuitive commitments to particular values, assuming their general accuracy. I will use an inference from the goal of a practice to the value of a practice, an inference based on the assumption that when we pursue something it is valuable. I will discuss our intuitive commitments to the value of justification. I will also rely on the implications of the presence of pride and admiration in relation to the outcome of an inquiry (especially in situations where a belief is difficult to form). By using this methodology, I will argue for three sources of value that explain the unique significance of the value of inquiry. The first is the value of its unique role in our being able to form reliably true beliefs. Second, I will argue for Wayne D. Riggs' account of epistemic credit; Riggs defends the value of our being responsible for true beliefs, they are our achievements. Third, I will argue for an additional the value of delivering a skilful epistemic performance, another kind of achievement. I will show that although the value of true belief plays a role in explaining some of the values, the third value for inquiry is independent of the value of true belief. This means that there are intellectual rewards, which can be gained from this practice, that extend beyond the value of true belief. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: Shapiro, Lucy Deborah
- Date: 2006 , 2013-06-14
- Subjects: Delusions , Knowledge, Theory of , Epistemics , Truth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2735 , http://hdl.handle.net/10962/d1005955 , Delusions , Knowledge, Theory of , Epistemics , Truth
- Description: The practice of inquiry, in which we seek and pursue true beliefs by forming justified beliefs, is important to us. This thesis will address two questions concerning the significance of this practice. These are the question of what explains our preference for this particular belief-forming practice, and whether this value can be explained by the value of true belief alone. To answer these questions I will examme a variety of our intuitive commitments to particular values, assuming their general accuracy. I will use an inference from the goal of a practice to the value of a practice, an inference based on the assumption that when we pursue something it is valuable. I will discuss our intuitive commitments to the value of justification. I will also rely on the implications of the presence of pride and admiration in relation to the outcome of an inquiry (especially in situations where a belief is difficult to form). By using this methodology, I will argue for three sources of value that explain the unique significance of the value of inquiry. The first is the value of its unique role in our being able to form reliably true beliefs. Second, I will argue for Wayne D. Riggs' account of epistemic credit; Riggs defends the value of our being responsible for true beliefs, they are our achievements. Third, I will argue for an additional the value of delivering a skilful epistemic performance, another kind of achievement. I will show that although the value of true belief plays a role in explaining some of the values, the third value for inquiry is independent of the value of true belief. This means that there are intellectual rewards, which can be gained from this practice, that extend beyond the value of true belief. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
Interactions of fishes with particular reference to coelacanths in the canyons at Sodwana Bay and the St Lucia Marine Protected Area of South Africa
- Heemstra, Phillip C, Frickle, H, Hissmann, K
- Authors: Heemstra, Phillip C , Frickle, H , Hissmann, K
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7130 , http://hdl.handle.net/10962/d1011771
- Description: The deep demersal fish fauna at depths of 100–400min canyons off the St Lucia Marine Protected Area along the north coast of KwaZulu-Natal is compared with similar fish communities at the Comoro Islands and in the Indo-Pacific region. Fifty-four fish species were seen or photographed from the submersible Jago or by the discovery team of scuba divers in the coelacanth, Latimeria chalumnae, habitat of the canyons off Sodwana Bay. An additional 94 fish species known from depths of 100–200 m along the coast of northern KwaZulu-Natal are likely to occur in the canyon habitat. The fish fauna of the Sodwana canyons shares at least 18 species with the deep demersal fish community off tropical coral reefs of the Indo-Pacific region. Thirty-seven of the Sodwana canyon fishes are also known from the coelacanth habitat in the Comoros.
- Full Text:
- Authors: Heemstra, Phillip C , Frickle, H , Hissmann, K
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7130 , http://hdl.handle.net/10962/d1011771
- Description: The deep demersal fish fauna at depths of 100–400min canyons off the St Lucia Marine Protected Area along the north coast of KwaZulu-Natal is compared with similar fish communities at the Comoro Islands and in the Indo-Pacific region. Fifty-four fish species were seen or photographed from the submersible Jago or by the discovery team of scuba divers in the coelacanth, Latimeria chalumnae, habitat of the canyons off Sodwana Bay. An additional 94 fish species known from depths of 100–200 m along the coast of northern KwaZulu-Natal are likely to occur in the canyon habitat. The fish fauna of the Sodwana canyons shares at least 18 species with the deep demersal fish community off tropical coral reefs of the Indo-Pacific region. Thirty-seven of the Sodwana canyon fishes are also known from the coelacanth habitat in the Comoros.
- Full Text:
Intersubjectivity and the schizophrenic experience: a hermeneutic phenomoneological exploration of being-in-relation
- Bradfield, Bruce Christopher
- Authors: Bradfield, Bruce Christopher
- Date: 2006
- Subjects: Schizophrenia , Intersubjectivity
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2940 , http://hdl.handle.net/10962/d1002449 , Schizophrenia , Intersubjectivity
- Description: This research project has its origin and motivation in work done by Lysaker, Johannesen and Lysaker (2005), which explored the experience of being as a person with schizophrenia in relation to other individuals. The researchers examined the nature of the schizophrenic experience from within the framework of the dialogical model of self, and presented schizophrenic intersubjectivity as a potentially horrifying and disintegrating experience. Lysaker et al (2005) discuss the notion that the individual self unfolds as a composite structure of multiple selves, existing in dialogical interaction with one another. Their research aimed to show that the individual with schizophrenia experiences difficulty tolerating this dialogue on an intrapsychic level. Because interpersonal exchange requires that individuals adopt a variety of self-other modes of relatedness, suggest Lysaker et al, interpersonal engagement for the person with schizophrenia is disclosed as profoundly threatening (ibid.) Moving from the above-mentioned research, this project aims through a hermeneutic phenomenological process to clarify and narrate the subtleties of the intersubjective experience, as that experience is disclosed in the lived world of a person with schizophrenia. How does such an individual experience self in relation to other? How does such an individual negotiate their sense of self in terms of their dialogicality? The phenomenological hermeneutic method, as shaped by such theorists as Gadamer (1976), Heidegger (1962) and Buber (1970), will emerge as the interpretive platform upon which these questions are approached.
- Full Text:
- Authors: Bradfield, Bruce Christopher
- Date: 2006
- Subjects: Schizophrenia , Intersubjectivity
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2940 , http://hdl.handle.net/10962/d1002449 , Schizophrenia , Intersubjectivity
- Description: This research project has its origin and motivation in work done by Lysaker, Johannesen and Lysaker (2005), which explored the experience of being as a person with schizophrenia in relation to other individuals. The researchers examined the nature of the schizophrenic experience from within the framework of the dialogical model of self, and presented schizophrenic intersubjectivity as a potentially horrifying and disintegrating experience. Lysaker et al (2005) discuss the notion that the individual self unfolds as a composite structure of multiple selves, existing in dialogical interaction with one another. Their research aimed to show that the individual with schizophrenia experiences difficulty tolerating this dialogue on an intrapsychic level. Because interpersonal exchange requires that individuals adopt a variety of self-other modes of relatedness, suggest Lysaker et al, interpersonal engagement for the person with schizophrenia is disclosed as profoundly threatening (ibid.) Moving from the above-mentioned research, this project aims through a hermeneutic phenomenological process to clarify and narrate the subtleties of the intersubjective experience, as that experience is disclosed in the lived world of a person with schizophrenia. How does such an individual experience self in relation to other? How does such an individual negotiate their sense of self in terms of their dialogicality? The phenomenological hermeneutic method, as shaped by such theorists as Gadamer (1976), Heidegger (1962) and Buber (1970), will emerge as the interpretive platform upon which these questions are approached.
- Full Text:
Investigating a rural community's use of communication technology: a study of Nakaseke Community Multi-media centre in Uganda
- Authors: Tumusiime, James
- Date: 2006
- Subjects: Information technology -- Uganda , Media programs (Education) -- Uganda , Communication in rural development -- Uganda , Communication -- Technological innovations -- Developing countries , Telecommuting centres -- Uganda
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3489 , http://hdl.handle.net/10962/d1002944 , Information technology -- Uganda , Media programs (Education) -- Uganda , Communication in rural development -- Uganda , Communication -- Technological innovations -- Developing countries , Telecommuting centres -- Uganda
- Description: An assumption that Information and Communication Technologies (ICTs) and economic development have an automatic linkage has gained wide acceptance over the last decade. As a result, developing countries are under pressure to apply this prescription as a solution to poverty. With the help of development partners in the developed world and the United Nations, developing countries have embraced this call to increase access to ICTs to bridge the ever-widening gap between the ‘information rich’ and ‘information poor’ (Castells, 2001). One of the strategies has been the establishment of telecentres where the least privileged people might access ICTs for their own development needs. However, this strategy has tended to overlook contextual factors and circumstances in developing countries. ICTs are thus being introduced in an environment of mass poverty, illiteracy and poor infrastructure, exacerbating existing inequalities in some cases. Much attention has been focussed on initiatives aimed at expanding the ICT infrastructure for wider population access without addressing what the users actually do with such access. This study aims to make a contribution in that direction. The study focuses on Nakaseke Community Multi-media Centre(CMC), the first telecentre introduced in Uganda in 1997. Using a combination of quantitative and qualitative research techniques, the study sets out to develop deeper insights into how the Nakaseke community uses, engages with and relates with communication technologies installed at the telecentre. It probes whether these practices advance the dominant view that ICTs are a panacea for rural development. The findings indicate that while access to communication technology has expanded, albeit at a slow pace, the benefits might take very long to have a significant effect as many targeted users do not make use of the facilities because they lack the human skills and financial resources to exploit the technologies. Other problems such as poor electricity supply and sustainability also actively militate against the potential of the project to deliver. Besides, people tend to appropriate technology in ways different from those intended by its promoters. As Burton (2002) explains through the concept of ‘affordances’ and ‘culture’, some users perceive technologies essentially as something that bestows the status of being modern or sophisticated on their community, rather than as a development tool. In conclusion, it is argued that if used for development, ICTs can indeed make a difference in the lives of rural people. However, besides investing in technology, there is need to invest more in empowering the people themselves with skills, particularly literacy, to enable them use ICTs productively.
- Full Text:
- Authors: Tumusiime, James
- Date: 2006
- Subjects: Information technology -- Uganda , Media programs (Education) -- Uganda , Communication in rural development -- Uganda , Communication -- Technological innovations -- Developing countries , Telecommuting centres -- Uganda
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3489 , http://hdl.handle.net/10962/d1002944 , Information technology -- Uganda , Media programs (Education) -- Uganda , Communication in rural development -- Uganda , Communication -- Technological innovations -- Developing countries , Telecommuting centres -- Uganda
- Description: An assumption that Information and Communication Technologies (ICTs) and economic development have an automatic linkage has gained wide acceptance over the last decade. As a result, developing countries are under pressure to apply this prescription as a solution to poverty. With the help of development partners in the developed world and the United Nations, developing countries have embraced this call to increase access to ICTs to bridge the ever-widening gap between the ‘information rich’ and ‘information poor’ (Castells, 2001). One of the strategies has been the establishment of telecentres where the least privileged people might access ICTs for their own development needs. However, this strategy has tended to overlook contextual factors and circumstances in developing countries. ICTs are thus being introduced in an environment of mass poverty, illiteracy and poor infrastructure, exacerbating existing inequalities in some cases. Much attention has been focussed on initiatives aimed at expanding the ICT infrastructure for wider population access without addressing what the users actually do with such access. This study aims to make a contribution in that direction. The study focuses on Nakaseke Community Multi-media Centre(CMC), the first telecentre introduced in Uganda in 1997. Using a combination of quantitative and qualitative research techniques, the study sets out to develop deeper insights into how the Nakaseke community uses, engages with and relates with communication technologies installed at the telecentre. It probes whether these practices advance the dominant view that ICTs are a panacea for rural development. The findings indicate that while access to communication technology has expanded, albeit at a slow pace, the benefits might take very long to have a significant effect as many targeted users do not make use of the facilities because they lack the human skills and financial resources to exploit the technologies. Other problems such as poor electricity supply and sustainability also actively militate against the potential of the project to deliver. Besides, people tend to appropriate technology in ways different from those intended by its promoters. As Burton (2002) explains through the concept of ‘affordances’ and ‘culture’, some users perceive technologies essentially as something that bestows the status of being modern or sophisticated on their community, rather than as a development tool. In conclusion, it is argued that if used for development, ICTs can indeed make a difference in the lives of rural people. However, besides investing in technology, there is need to invest more in empowering the people themselves with skills, particularly literacy, to enable them use ICTs productively.
- Full Text:
Investigating the effects of the proliferation of commercial broadcasting on public service broadcasting: the case of Rivers State of Nigeria Broadcasting Corporation
- Authors: Da-Wariboko, Biobele
- Date: 2006
- Subjects: Nigerian Broadcasting Corporation , Broadcasting -- Social aspects -- Nigeria , Mass media -- Social aspects -- Nigeria , Radio Broadcasting -- Social aspects -- Nigeria , Radio in community development , Radio stations -- Nigeria , Radio broadcasting -- Rivers State (Nigeria) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3423 , http://hdl.handle.net/10962/d1002876 , Nigerian Broadcasting Corporation , Broadcasting -- Social aspects -- Nigeria , Mass media -- Social aspects -- Nigeria , Radio Broadcasting -- Social aspects -- Nigeria , Radio in community development , Radio stations -- Nigeria , Radio broadcasting -- Rivers State (Nigeria) -- History
- Description: 1992 marked a turning point in Nigeria’s broadcasting history as the country formally deregulated her broadcast space. However, it was not until March 2002 that the first commercial radio station was established in Rivers State, a broadcast environment hitherto monopolised by Radio Rivers. The coming of the first independent radio station in Rivers State in March 2002 was followed by the establishment of two other stations in October 2003 and November 2003 respectively. As important as these events in broadcasting in Rivers State are, however, media scholars have argued that in most societies where such change has taken place, public service broadcasters have tampered with their values of being an open space where individuals and groups can come together to be educated, informed, and entertained. This study investigates the extent to which the proliferation of commercial broadcasting outlets has affected Radio Rivers’ public service programming and scheduling. Using a combination of qualitative and quantitative research methods, through in-depth interviews and analysis of the mandate and programme schedules, the study established that while Radio Rivers still maintains some public service values, its current programming policy is driven by the need to compete with the commercial broadcasters. This is evidenced in the decrease in the programme space allocated to current affairs and educational programmes on the schedule, (the genre of public service broadcasting), and the increase in attention to advertisements and entertainment programmes, (the genre of commercial broadcasting). The study also confirms the adverse effects of dwindling financial resources as forcing public service radios to compromise on their public service values, as majority of programmes on Radio Rivers current programme schedules are now geared towards attracting advertisers rather than serving the public good and interests. However, the study proved that it is not in all cases that the entry of commercial broadcasters into Rivers State broadcast space has undermined Radio Rivers public service values. Indeed, in leading to the expansion of interactive, news, and the diversification of entertainment programmes spaces on Radio Rivers’ programming schedules, the proliferation of commercial broadcasters has yielded some positive effects on Radio Rivers public service values and contribution to the public sphere. The study further highlights the need for some policy reforms at Radio Rivers, such as the introduction of licence fees, increased government funding and loosening government’s current control over the station. In addition, there is the need for the edict establishing the station to be amended to reflect the current trends in broadcasting in Rivers State, and above all to reposition Radio Rivers to sustain public good and public interests in its programming.
- Full Text:
- Authors: Da-Wariboko, Biobele
- Date: 2006
- Subjects: Nigerian Broadcasting Corporation , Broadcasting -- Social aspects -- Nigeria , Mass media -- Social aspects -- Nigeria , Radio Broadcasting -- Social aspects -- Nigeria , Radio in community development , Radio stations -- Nigeria , Radio broadcasting -- Rivers State (Nigeria) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3423 , http://hdl.handle.net/10962/d1002876 , Nigerian Broadcasting Corporation , Broadcasting -- Social aspects -- Nigeria , Mass media -- Social aspects -- Nigeria , Radio Broadcasting -- Social aspects -- Nigeria , Radio in community development , Radio stations -- Nigeria , Radio broadcasting -- Rivers State (Nigeria) -- History
- Description: 1992 marked a turning point in Nigeria’s broadcasting history as the country formally deregulated her broadcast space. However, it was not until March 2002 that the first commercial radio station was established in Rivers State, a broadcast environment hitherto monopolised by Radio Rivers. The coming of the first independent radio station in Rivers State in March 2002 was followed by the establishment of two other stations in October 2003 and November 2003 respectively. As important as these events in broadcasting in Rivers State are, however, media scholars have argued that in most societies where such change has taken place, public service broadcasters have tampered with their values of being an open space where individuals and groups can come together to be educated, informed, and entertained. This study investigates the extent to which the proliferation of commercial broadcasting outlets has affected Radio Rivers’ public service programming and scheduling. Using a combination of qualitative and quantitative research methods, through in-depth interviews and analysis of the mandate and programme schedules, the study established that while Radio Rivers still maintains some public service values, its current programming policy is driven by the need to compete with the commercial broadcasters. This is evidenced in the decrease in the programme space allocated to current affairs and educational programmes on the schedule, (the genre of public service broadcasting), and the increase in attention to advertisements and entertainment programmes, (the genre of commercial broadcasting). The study also confirms the adverse effects of dwindling financial resources as forcing public service radios to compromise on their public service values, as majority of programmes on Radio Rivers current programme schedules are now geared towards attracting advertisers rather than serving the public good and interests. However, the study proved that it is not in all cases that the entry of commercial broadcasters into Rivers State broadcast space has undermined Radio Rivers public service values. Indeed, in leading to the expansion of interactive, news, and the diversification of entertainment programmes spaces on Radio Rivers’ programming schedules, the proliferation of commercial broadcasters has yielded some positive effects on Radio Rivers public service values and contribution to the public sphere. The study further highlights the need for some policy reforms at Radio Rivers, such as the introduction of licence fees, increased government funding and loosening government’s current control over the station. In addition, there is the need for the edict establishing the station to be amended to reflect the current trends in broadcasting in Rivers State, and above all to reposition Radio Rivers to sustain public good and public interests in its programming.
- Full Text:
Investigating the viability of a framework for small scale, easily deployable and extensible hotspot management systems
- Authors: Thinyane, Mamello P
- Date: 2006
- Subjects: Local area networks (Computer networks) , Computer networks -- Management , Computer network architectures , Computer network protocols , Wireless communication systems , XML (Document markup language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4638 , http://hdl.handle.net/10962/d1006553
- Description: The proliferation of PALs (Public Access Locations) is fuelling the development of new standards, protocols, services, and applications for WLANs (Wireless Local Area Networks). PALs are set up at public locations to meet continually changing, multiservice, multi-protocol user requirements. This research investigates the essential infrastructural requirements that will enable further proliferation of PALs, and consequently facilitate ubiquitous computing. Based on these requirements, an extensible architectural framework for PAL management systems that inherently facilitates the provisioning of multiple services and multiple protocols on PALs is derived. The ensuing framework, which is called Xobogel, is based on the microkernel architectural pattern, and the IPDR (Internet Protocol Data Record) specification. Xobogel takes into consideration and supports the implementation of diverse business models for PALs, in respect of distinct environmental factors. It also facilitates next-generation network service usage accounting through a simple, flexible, and extensible XML based usage record. The framework is subsequently validated for service element extensibility and simplicity through the design, implementation, and experimental deployment of SEHS (Small Extensible Hotspot System), a system based on the framework. The robustness and scalability of the framework is observed to be sufficient for SMME deployment, withstanding the stress testing experiments performed on SEHS. The range of service element and charging modules implemented confirm an acceptable level of flexibility and extensibility within the framework.
- Full Text:
- Authors: Thinyane, Mamello P
- Date: 2006
- Subjects: Local area networks (Computer networks) , Computer networks -- Management , Computer network architectures , Computer network protocols , Wireless communication systems , XML (Document markup language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4638 , http://hdl.handle.net/10962/d1006553
- Description: The proliferation of PALs (Public Access Locations) is fuelling the development of new standards, protocols, services, and applications for WLANs (Wireless Local Area Networks). PALs are set up at public locations to meet continually changing, multiservice, multi-protocol user requirements. This research investigates the essential infrastructural requirements that will enable further proliferation of PALs, and consequently facilitate ubiquitous computing. Based on these requirements, an extensible architectural framework for PAL management systems that inherently facilitates the provisioning of multiple services and multiple protocols on PALs is derived. The ensuing framework, which is called Xobogel, is based on the microkernel architectural pattern, and the IPDR (Internet Protocol Data Record) specification. Xobogel takes into consideration and supports the implementation of diverse business models for PALs, in respect of distinct environmental factors. It also facilitates next-generation network service usage accounting through a simple, flexible, and extensible XML based usage record. The framework is subsequently validated for service element extensibility and simplicity through the design, implementation, and experimental deployment of SEHS (Small Extensible Hotspot System), a system based on the framework. The robustness and scalability of the framework is observed to be sufficient for SMME deployment, withstanding the stress testing experiments performed on SEHS. The range of service element and charging modules implemented confirm an acceptable level of flexibility and extensibility within the framework.
- Full Text:
Ionospheric total electron content variability and its influence in radio astronomy
- Authors: Botai, Ondego Joel
- Date: 2006
- Subjects: Electrons , Global Positioning System , Global Positioning System -- Data processing , Ionosphere , Ionospheric radio wave propagation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5473 , http://hdl.handle.net/10962/d1005258 , Electrons , Global Positioning System , Global Positioning System -- Data processing , Ionosphere , Ionospheric radio wave propagation
- Description: Ionospheric phase delays of radio signals from Global Positioning System (GPS) satellites have been used to compute ionospheric Total Electron Content (TEC). An extended Chapman profle model is used to estimate the electron density profles and TEC. The Chapman profle that can be used to predict TEC over the mid-latitudes only applies during day time. To model night time TEC variability, a polynomial function is fitted to the night time peak electron density profles derived from the online International Reference Ionosphere (IRI) 2001. The observed and predicted TEC and its variability have been used to study ionospheric in°uence on Radio Astronomy in South Africa region. Di®erential phase delays of the radio signals from Radio Astronomy sources have been simulated using TEC. Using the simulated phase delays, the azimuth and declination o®sets of the radio sources have been estimated. Results indicate that, pointing errors of the order of miliarcseconds (mas) are likely if the ionospheric phase delays are not corrected for. These delays are not uniform and vary over a broad spectrum of timescales. This implies that fast frequency (referencing) switching, closure phases and fringe ¯tting schemes for ionospheric correction in astrometry are not the best option as they do not capture the real state of the ionosphere especially if the switching time is greater than the ionospheric TEC variability. However, advantage can be taken of the GPS satellite data available at intervals of a second from the GPS receiver network in South Africa to derive parameters which could be used to correct for the ionospheric delays. Furthermore GPS data can also be used to monitor the occurrence of scintillations, (which might corrupt radio signals) especially for the proposed, Square Kilometer Array (SKA) stations closer to the equatorial belt during magnetic storms and sub-storms. A 10 minute snapshot of GPS data recorded with the Hermanus [34:420 S, 19:220 E ] dual frequency receiver on 2003-04-11 did not show the occurrence of scintillations. This time scale is however too short and cannot be representative. Longer time scales; hours, days, seasons are needed to monitor the occurrence of scintillations.
- Full Text:
- Authors: Botai, Ondego Joel
- Date: 2006
- Subjects: Electrons , Global Positioning System , Global Positioning System -- Data processing , Ionosphere , Ionospheric radio wave propagation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5473 , http://hdl.handle.net/10962/d1005258 , Electrons , Global Positioning System , Global Positioning System -- Data processing , Ionosphere , Ionospheric radio wave propagation
- Description: Ionospheric phase delays of radio signals from Global Positioning System (GPS) satellites have been used to compute ionospheric Total Electron Content (TEC). An extended Chapman profle model is used to estimate the electron density profles and TEC. The Chapman profle that can be used to predict TEC over the mid-latitudes only applies during day time. To model night time TEC variability, a polynomial function is fitted to the night time peak electron density profles derived from the online International Reference Ionosphere (IRI) 2001. The observed and predicted TEC and its variability have been used to study ionospheric in°uence on Radio Astronomy in South Africa region. Di®erential phase delays of the radio signals from Radio Astronomy sources have been simulated using TEC. Using the simulated phase delays, the azimuth and declination o®sets of the radio sources have been estimated. Results indicate that, pointing errors of the order of miliarcseconds (mas) are likely if the ionospheric phase delays are not corrected for. These delays are not uniform and vary over a broad spectrum of timescales. This implies that fast frequency (referencing) switching, closure phases and fringe ¯tting schemes for ionospheric correction in astrometry are not the best option as they do not capture the real state of the ionosphere especially if the switching time is greater than the ionospheric TEC variability. However, advantage can be taken of the GPS satellite data available at intervals of a second from the GPS receiver network in South Africa to derive parameters which could be used to correct for the ionospheric delays. Furthermore GPS data can also be used to monitor the occurrence of scintillations, (which might corrupt radio signals) especially for the proposed, Square Kilometer Array (SKA) stations closer to the equatorial belt during magnetic storms and sub-storms. A 10 minute snapshot of GPS data recorded with the Hermanus [34:420 S, 19:220 E ] dual frequency receiver on 2003-04-11 did not show the occurrence of scintillations. This time scale is however too short and cannot be representative. Longer time scales; hours, days, seasons are needed to monitor the occurrence of scintillations.
- Full Text:
Is economic impact a good way of justifying the inclusion of foreign students at local universities?
- Snowball, Jeanette D, Antrobus, Geoffrey G
- Authors: Snowball, Jeanette D , Antrobus, Geoffrey G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67470 , vital:29098 , http://dx.doi.org/10.4314/sajhe.v20i3.25593
- Description: Pre-print , In the debate surrounding the costs and benefits of having foreign students at South African universities, the financial contributions of foreign students to their host economies is sometimes cited. This article reports the results of a comparison between the economic impact on the Grahamstown economy of the spending of foreign and local students at Rhodes University. It finds that the spending patterns of both types of students are remarkably similar and that the somewhat higher economic impact of foreign students is largely as a result of their propensity to choose the more expensive residence accommodation, rather than as a result of greater average spending generally. We suggest that economic impact studies should be used with caution when making the case for continued public subsidy of goods with significant non-market values and that opportunity costs should also be considered.
- Full Text:
Is economic impact a good way of justifying the inclusion of foreign students at local universities?
- Authors: Snowball, Jeanette D , Antrobus, Geoffrey G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67470 , vital:29098 , http://dx.doi.org/10.4314/sajhe.v20i3.25593
- Description: Pre-print , In the debate surrounding the costs and benefits of having foreign students at South African universities, the financial contributions of foreign students to their host economies is sometimes cited. This article reports the results of a comparison between the economic impact on the Grahamstown economy of the spending of foreign and local students at Rhodes University. It finds that the spending patterns of both types of students are remarkably similar and that the somewhat higher economic impact of foreign students is largely as a result of their propensity to choose the more expensive residence accommodation, rather than as a result of greater average spending generally. We suggest that economic impact studies should be used with caution when making the case for continued public subsidy of goods with significant non-market values and that opportunity costs should also be considered.
- Full Text:
Is land tenure a significant variable for promoting agricultural productivity in rural villages?: the case study of Nonkcampa Village in the Buffalo City Municipality, Province of the Eastern Cape, South Africa
- Authors: Gqokoma, Daniel Atwell
- Date: 2006
- Subjects: Buffalo City (South Africa) , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land reform -- South Africa -- Eastern Cape , Land use -- Government policy -- South Africa -- Eastern Cape , Agriculture -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3313 , http://hdl.handle.net/10962/d1003101 , Buffalo City (South Africa) , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land reform -- South Africa -- Eastern Cape , Land use -- Government policy -- South Africa -- Eastern Cape , Agriculture -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape
- Description: The research explored the causal relationship between the communal land tenure and the stagnant agricultural productivity in rural villages. It is assumed that there is covariance between the communal land tenure and the stagnant agricultural productivity. The communal land tenure deprived the villagers of the land ownership rights to mortgage their landholdings to secure agricultural credit from financial institutions, or to advance them as own contributions to obtain Government-provided grants under the ILRAD. Under such circumstances, the villagers could not raise the level of agricultural productivity. The Permit to Occupy (PTO) certificates, issued to the landholders, provided for usufruct rights only i.e. right to occupy and use an allotment. The related research was conducted at Nonkcampa village. The metatheory, “Positivism” and the quantitative paradigm were applied to collate and analyse the data. The research findings confirmed the correlation between the land tenure and the agricultural productivity, as the respondents claimed not to have had any access to agricultural inputs. Hence, the agricultural productivity on the arable land had stagnated.
- Full Text:
- Authors: Gqokoma, Daniel Atwell
- Date: 2006
- Subjects: Buffalo City (South Africa) , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land reform -- South Africa -- Eastern Cape , Land use -- Government policy -- South Africa -- Eastern Cape , Agriculture -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3313 , http://hdl.handle.net/10962/d1003101 , Buffalo City (South Africa) , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land reform -- South Africa -- Eastern Cape , Land use -- Government policy -- South Africa -- Eastern Cape , Agriculture -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape
- Description: The research explored the causal relationship between the communal land tenure and the stagnant agricultural productivity in rural villages. It is assumed that there is covariance between the communal land tenure and the stagnant agricultural productivity. The communal land tenure deprived the villagers of the land ownership rights to mortgage their landholdings to secure agricultural credit from financial institutions, or to advance them as own contributions to obtain Government-provided grants under the ILRAD. Under such circumstances, the villagers could not raise the level of agricultural productivity. The Permit to Occupy (PTO) certificates, issued to the landholders, provided for usufruct rights only i.e. right to occupy and use an allotment. The related research was conducted at Nonkcampa village. The metatheory, “Positivism” and the quantitative paradigm were applied to collate and analyse the data. The research findings confirmed the correlation between the land tenure and the agricultural productivity, as the respondents claimed not to have had any access to agricultural inputs. Hence, the agricultural productivity on the arable land had stagnated.
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Isolation, purification and characterization of a novel glucose oxidase from Penicillium canescens Tt42
- Authors: Simpson, Clinton
- Date: 2006
- Subjects: Penicillium , Glucose , Oxidases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3975 , http://hdl.handle.net/10962/d1004034 , Penicillium , Glucose , Oxidases
- Description: A novel glucose oxidase from Penicillium canescens (Tt42) was isolated, purified and characterised. The P. canescens Tt42 was cultivated using an optimised growth medium from literature, and maximum glucose oxidase activities of 11.5 U/ml and 6.9 U/ml for the intra- and extracellular fractions were obtained. Maximum glucose oxidase production was achieved after 72 hours at 28°C which coincided with glucose depletion. A total of 1104 U (from 60ml) of glucose oxidase was produced with a biomass specific glucose oxidase activity of 1.08 Umg[superscript -1] Four methods of cell disruption were evaluated for release of intracellular glucose oxidase from P. canescens Tt42 cells. These methods were; sonication, French press, Freeze-Thaw and a high pressure cell disrupter (Z-Plus Series) from Constant systems. All the methods were successful in releasing the intracellular glucose oxidase from P. canescens Tt42. The use of the Constant Systems high pressure cell disrupter was preferred, since it was the simplest and most rapid method. Ammonium sulphate precipitation was shown to be effective as an initial purification step for extracellular glucose oxidase from P. canescens Tt42. Comparison of the intra- and extracellular glucose oxidase fractions using isoelectric focusing showed 2 isoenzymes in both fractions. The pI values of the isoenzymes were determined to be 4.30 and 4.67, with the former being dominant. Since both the intra- and extracellular fractions contained the same isoenzymes of glucose oxidase, further purification studies were performed using the extracellular fraction. The glucose oxidase from P. canescens Tt42 was purified using 3 main techniques: ammonium sulphate precipitation (60% - 70% cut), anion exchange chromatography (Super Q 650M) and size exclusion chromatography (Sephadex S200HR). The glucose oxidase was determined to be ±80% pure by size exclusion chromatography. The final purified glucose oxidase was lyophilised, and an overall purification yield of 10.3% was achieved with an 8.6-fold purification. The purified glucose oxidase was confirmed to be catalase free. Glucose oxidase from P. canescens Tt42 was determined to be a dimeric protein (M[subscript r] ±148kDa) likely consisting of 2 equal subunits (M[subscript r] ± 70kDa). The temperature optimum range was shown to be 25-30°C. The optimum pH for the oxidation of β-D-glucose was pH 7. The enzyme was shown to be stable at 25°C for 10 hours, with a half life of approximately 30 minutes at 37°C. The lyophilised enzyme was stable at -20°C for 6 months. The properties of glucose oxidase from Tt42 were comparable to alternative glucose oxidase enzymes from Aspergillus and other Penicillium species. Glucose oxidase from P. canescens Tt42 was shown to have distinct kinetic characteristics. The V[subscript max] and K[subscript m] were shown to be 651 Umg[superscript -1] and 18.4 mM towards β-D-glucose. The catalytic kcat and specificity k[subscript cat]/K[subscript m] constants for glucose oxidase from P. canescens Tt42 were shown to be 791 s[superscript -1] and 40 s[superscript -1]mM[superscript -1] each respectively. The specificity constant (k[subscript cat]/K[subscript m]) of glucose oxidase from P. canescens Tt42 was determined to be 1.3-fold higher than that that of A. niger (Sigma Type VII) and 8.7-fold lower than that of P. amagasakiense (ATCC 28686) from literature.
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- Authors: Simpson, Clinton
- Date: 2006
- Subjects: Penicillium , Glucose , Oxidases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3975 , http://hdl.handle.net/10962/d1004034 , Penicillium , Glucose , Oxidases
- Description: A novel glucose oxidase from Penicillium canescens (Tt42) was isolated, purified and characterised. The P. canescens Tt42 was cultivated using an optimised growth medium from literature, and maximum glucose oxidase activities of 11.5 U/ml and 6.9 U/ml for the intra- and extracellular fractions were obtained. Maximum glucose oxidase production was achieved after 72 hours at 28°C which coincided with glucose depletion. A total of 1104 U (from 60ml) of glucose oxidase was produced with a biomass specific glucose oxidase activity of 1.08 Umg[superscript -1] Four methods of cell disruption were evaluated for release of intracellular glucose oxidase from P. canescens Tt42 cells. These methods were; sonication, French press, Freeze-Thaw and a high pressure cell disrupter (Z-Plus Series) from Constant systems. All the methods were successful in releasing the intracellular glucose oxidase from P. canescens Tt42. The use of the Constant Systems high pressure cell disrupter was preferred, since it was the simplest and most rapid method. Ammonium sulphate precipitation was shown to be effective as an initial purification step for extracellular glucose oxidase from P. canescens Tt42. Comparison of the intra- and extracellular glucose oxidase fractions using isoelectric focusing showed 2 isoenzymes in both fractions. The pI values of the isoenzymes were determined to be 4.30 and 4.67, with the former being dominant. Since both the intra- and extracellular fractions contained the same isoenzymes of glucose oxidase, further purification studies were performed using the extracellular fraction. The glucose oxidase from P. canescens Tt42 was purified using 3 main techniques: ammonium sulphate precipitation (60% - 70% cut), anion exchange chromatography (Super Q 650M) and size exclusion chromatography (Sephadex S200HR). The glucose oxidase was determined to be ±80% pure by size exclusion chromatography. The final purified glucose oxidase was lyophilised, and an overall purification yield of 10.3% was achieved with an 8.6-fold purification. The purified glucose oxidase was confirmed to be catalase free. Glucose oxidase from P. canescens Tt42 was determined to be a dimeric protein (M[subscript r] ±148kDa) likely consisting of 2 equal subunits (M[subscript r] ± 70kDa). The temperature optimum range was shown to be 25-30°C. The optimum pH for the oxidation of β-D-glucose was pH 7. The enzyme was shown to be stable at 25°C for 10 hours, with a half life of approximately 30 minutes at 37°C. The lyophilised enzyme was stable at -20°C for 6 months. The properties of glucose oxidase from Tt42 were comparable to alternative glucose oxidase enzymes from Aspergillus and other Penicillium species. Glucose oxidase from P. canescens Tt42 was shown to have distinct kinetic characteristics. The V[subscript max] and K[subscript m] were shown to be 651 Umg[superscript -1] and 18.4 mM towards β-D-glucose. The catalytic kcat and specificity k[subscript cat]/K[subscript m] constants for glucose oxidase from P. canescens Tt42 were shown to be 791 s[superscript -1] and 40 s[superscript -1]mM[superscript -1] each respectively. The specificity constant (k[subscript cat]/K[subscript m]) of glucose oxidase from P. canescens Tt42 was determined to be 1.3-fold higher than that that of A. niger (Sigma Type VII) and 8.7-fold lower than that of P. amagasakiense (ATCC 28686) from literature.
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