Graph matching with subdivision surfaces for texture synthesis on surfaces
- Bangay, Shaun D, Morkel, Chantelle
- Authors: Bangay, Shaun D , Morkel, Chantelle
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433351 , vital:72964 , https://doi.org/10.1145/1108590.1108601
- Description: Existing texture synthesis-from example strategies for polygon meshes typically make use of three components: a multi-resolution mesh hierarchy that allows the overall nature of the pattern to be reproduced before filling in detail; a matching strategy that extends the synthesized texture using the best fit from a texture sample; and a transfer mechanism that copies the selected portion of the texture sample to the target surface. We introduce novel alternatives for each of these components. Use of √2-subdivision surfaces provides the mesh hierarchy and allows fine control over the surface complexity. Adaptive subdivision is used to create an even vertex distribution over the surface. Use of the graph defined by a surface region for matching, rather than a regular texture neighbourhood, provides for flexible control over the scale of the texture and allows simultaneous matching against multiple levels of an image pyramid created from the texture sample. We use graph cuts for texture transfer, adapting this scheme to the context of surface synthesis. The resulting surface textures are realistic, tolerant of local mesh detail and are comparable to results produced by texture neighbourhood sampling approaches.
- Full Text:
- Authors: Bangay, Shaun D , Morkel, Chantelle
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433351 , vital:72964 , https://doi.org/10.1145/1108590.1108601
- Description: Existing texture synthesis-from example strategies for polygon meshes typically make use of three components: a multi-resolution mesh hierarchy that allows the overall nature of the pattern to be reproduced before filling in detail; a matching strategy that extends the synthesized texture using the best fit from a texture sample; and a transfer mechanism that copies the selected portion of the texture sample to the target surface. We introduce novel alternatives for each of these components. Use of √2-subdivision surfaces provides the mesh hierarchy and allows fine control over the surface complexity. Adaptive subdivision is used to create an even vertex distribution over the surface. Use of the graph defined by a surface region for matching, rather than a regular texture neighbourhood, provides for flexible control over the scale of the texture and allows simultaneous matching against multiple levels of an image pyramid created from the texture sample. We use graph cuts for texture transfer, adapting this scheme to the context of surface synthesis. The resulting surface textures are realistic, tolerant of local mesh detail and are comparable to results produced by texture neighbourhood sampling approaches.
- Full Text:
Hierarchical rule generalisation for speaker identification in fiction books
- Glass, Kevin R, Bangay, Shaun D
- Authors: Glass, Kevin R , Bangay, Shaun D
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433174 , vital:72949 , https://doi.org/10.1145/1216262.1216266
- Description: This paper presents a hierarchical pattern matching and generalisation technique which is applied to the problem of locating the correct speaker of quoted speech found in fiction books. Patterns from a training set are generalised to create a small number of rules, which can be used to identify items of interest within the text. The pattern matching technique is applied to finding the Speech-Verb, Actor and Speaker of quotes found in fiction books. The technique performs well over the training data, resulting in rule-sets many times smaller than the training set, but providing very high accuracy. While the rule-set generalised from one book is less effective when applied to different books than an approach based on hand coded heuristics, performance is comparable when testing on data closely related to the training set.
- Full Text:
- Authors: Glass, Kevin R , Bangay, Shaun D
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433174 , vital:72949 , https://doi.org/10.1145/1216262.1216266
- Description: This paper presents a hierarchical pattern matching and generalisation technique which is applied to the problem of locating the correct speaker of quoted speech found in fiction books. Patterns from a training set are generalised to create a small number of rules, which can be used to identify items of interest within the text. The pattern matching technique is applied to finding the Speech-Verb, Actor and Speaker of quotes found in fiction books. The technique performs well over the training data, resulting in rule-sets many times smaller than the training set, but providing very high accuracy. While the rule-set generalised from one book is less effective when applied to different books than an approach based on hand coded heuristics, performance is comparable when testing on data closely related to the training set.
- Full Text:
Household fuelwood use in small electrified towns of the Makana District, Eastern Cape, South Africa
- Shackleton, Charlie M, Gambiza, James, Jones, R
- Authors: Shackleton, Charlie M , Gambiza, James , Jones, R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182362 , vital:43823 , xlink:href="https://doi.org/10.17159/2413-3051/2007/v18i4a3394"
- Description: Access to secure energy supplies is a key foundation for sustainable development. Consequently local planning and development initiatives must be based on a sound knowledge of the energy use patterns and preferences of local users. This paper reports on such for three small urban settlements in the Eastern Cape Province, with a particular focus on fuelwood use. Despite widespread electrification over a decade ago, and perceptions that the ease of fuelwood collection was declining, most households continued to use fuelwood for cooking and space heating, whereas electricity was favoured for lighting. The most common reason for this was because fuelwood was cheap (or free) compared to electricity. Annual demand was approximately 1 450 kg per household per year. Households that collected their own supplies of fuelwood were significantly poorer than those that either bought their stocks, or those that did not use fuelwood at all. Indigenous species were favoured over exotic species, although fuelwood vendors traded mostly in exotic species, particularly Eucalyptus and wattle. The greater reliance of poorer and unelectrified households on fuelwood requires that local authorities consider this in energy planning, otherwise the poor will be neglected in policies such as the Free Basic Electricity.
- Full Text:
Household fuelwood use in small electrified towns of the Makana District, Eastern Cape, South Africa
- Authors: Shackleton, Charlie M , Gambiza, James , Jones, R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182362 , vital:43823 , xlink:href="https://doi.org/10.17159/2413-3051/2007/v18i4a3394"
- Description: Access to secure energy supplies is a key foundation for sustainable development. Consequently local planning and development initiatives must be based on a sound knowledge of the energy use patterns and preferences of local users. This paper reports on such for three small urban settlements in the Eastern Cape Province, with a particular focus on fuelwood use. Despite widespread electrification over a decade ago, and perceptions that the ease of fuelwood collection was declining, most households continued to use fuelwood for cooking and space heating, whereas electricity was favoured for lighting. The most common reason for this was because fuelwood was cheap (or free) compared to electricity. Annual demand was approximately 1 450 kg per household per year. Households that collected their own supplies of fuelwood were significantly poorer than those that either bought their stocks, or those that did not use fuelwood at all. Indigenous species were favoured over exotic species, although fuelwood vendors traded mostly in exotic species, particularly Eucalyptus and wattle. The greater reliance of poorer and unelectrified households on fuelwood requires that local authorities consider this in energy planning, otherwise the poor will be neglected in policies such as the Free Basic Electricity.
- Full Text:
Household wealth status and natural resource use in the Kat River valley, South Africa
- Shackleton, Charlie M, Shackleton, Sheona E
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181301 , vital:43717 , xlink:href="https://doi.org/10.1016/j.ecolecon.2005.04.011"
- Description: Much work has demonstrated the significant role and value of non-timber forest products (NTFPs) in the livelihoods of rural people in southern Africa and elsewhere. The findings provide a mean or composite picture, averaged across the sample households within each community. Yet, within any given community, there is significant socio-economic differentiation. It is important to acknowledge such differentiation when considering policy and management interventions to support rural livelihoods and promote sustainable resource use. This paper reports on a study in South Africa, the objective of which was to explore wealth-related differences and similarities in the use and value of NTFPs. Data on NTFP consumption, purchase, and sale were collected from households in three rural villages. Households were divided into three wealth classes and patterns of NTFPs use between the classes examined. There was no difference in the proportions of households in each wealth class using NTFPs, nor the total number of NTFPs used per household. Yet, there was some supporting evidence that poorer households derive greater benefits from NTFPs than do wealthy or intermediate households. One clear difference was that, with increasing wealth, households purchased significantly more NTFPs, and a greater proportion of wealthy households did so. Conversely, a greater proportion of poor households were involved in the sale of one or more NTFPs, and they sold a greater number per household, compared to wealthy and intermediate households. Detailed examination of use and value of four NTFPs (fuelwood, wild fruits, edible herbs, and grass hand brushes) revealed that in all instances, the poorest households used more of the resource per capita than the other wealth classes. This was not the case for comparisons based on the total household as the unit of analysis. Gross annual direct-use value did not differ between the wealth classes for any of the four NTFPs examined, at the household level. But on a per capita basis, a significantly higher gross annual direct-use value was evident within poorer households for fuelwood and edible herbs. The significance of these differences is discussed.
- Full Text:
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181301 , vital:43717 , xlink:href="https://doi.org/10.1016/j.ecolecon.2005.04.011"
- Description: Much work has demonstrated the significant role and value of non-timber forest products (NTFPs) in the livelihoods of rural people in southern Africa and elsewhere. The findings provide a mean or composite picture, averaged across the sample households within each community. Yet, within any given community, there is significant socio-economic differentiation. It is important to acknowledge such differentiation when considering policy and management interventions to support rural livelihoods and promote sustainable resource use. This paper reports on a study in South Africa, the objective of which was to explore wealth-related differences and similarities in the use and value of NTFPs. Data on NTFP consumption, purchase, and sale were collected from households in three rural villages. Households were divided into three wealth classes and patterns of NTFPs use between the classes examined. There was no difference in the proportions of households in each wealth class using NTFPs, nor the total number of NTFPs used per household. Yet, there was some supporting evidence that poorer households derive greater benefits from NTFPs than do wealthy or intermediate households. One clear difference was that, with increasing wealth, households purchased significantly more NTFPs, and a greater proportion of wealthy households did so. Conversely, a greater proportion of poor households were involved in the sale of one or more NTFPs, and they sold a greater number per household, compared to wealthy and intermediate households. Detailed examination of use and value of four NTFPs (fuelwood, wild fruits, edible herbs, and grass hand brushes) revealed that in all instances, the poorest households used more of the resource per capita than the other wealth classes. This was not the case for comparisons based on the total household as the unit of analysis. Gross annual direct-use value did not differ between the wealth classes for any of the four NTFPs examined, at the household level. But on a per capita basis, a significantly higher gross annual direct-use value was evident within poorer households for fuelwood and edible herbs. The significance of these differences is discussed.
- Full Text:
Identifying and Investigating Intrusive Scanning Patterns by Visualizing Network Telescope Traffic in a 3-D Scatter-plot
- van Riel, Jean-Pierre, Irwin, Barry V W
- Authors: van Riel, Jean-Pierre , Irwin, Barry V W
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428719 , vital:72531 , https://citeseerx.ist.psu.edu/document?repid=rep1type=pdfanddoi=aeb0738f0e53a8c9f407fee7e55c852643f2644c
- Description: Detecting and investigating intrusive Internet activity is an ever-present challenge for network administrators and security researchers. Network monitoring can generate large, unmanageable amounts of log data, which further complicates distinguishing between illegitimate and legiti-mate traffic. Considering the above issue, this article has two aims. First, it describes an investigative methodology for network monitoring and traffic review; and second, it discusses results from applying this meth-od. The method entails a combination of network telescope traffic cap-ture and visualisation. Observing traffic from the perspective of a dedi-cated sensor network reduces the volume of data and alleviates the concern of confusing malicious traffic with legitimate traffic. Compliment-ing this, visual analysis facilitates the rapid review and correlation of events, thereby utilizing human intelligence in the identification of scan-ning patterns. To demonstrate the proposed method, several months of network telescope traffic is captured and analysed with a tailor made 3D scatter-plot visualisation. As the results show, the visualisation saliently conveys anomalous patterns, and further analysis reveals that these patterns are indicative of covert network probing activity. By incorporat-ing visual analysis with traditional approaches, such as textual log re-view and the use of an intrusion detection system, this research contrib-utes improved insight into network scanning incidents.
- Full Text:
- Authors: van Riel, Jean-Pierre , Irwin, Barry V W
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428719 , vital:72531 , https://citeseerx.ist.psu.edu/document?repid=rep1type=pdfanddoi=aeb0738f0e53a8c9f407fee7e55c852643f2644c
- Description: Detecting and investigating intrusive Internet activity is an ever-present challenge for network administrators and security researchers. Network monitoring can generate large, unmanageable amounts of log data, which further complicates distinguishing between illegitimate and legiti-mate traffic. Considering the above issue, this article has two aims. First, it describes an investigative methodology for network monitoring and traffic review; and second, it discusses results from applying this meth-od. The method entails a combination of network telescope traffic cap-ture and visualisation. Observing traffic from the perspective of a dedi-cated sensor network reduces the volume of data and alleviates the concern of confusing malicious traffic with legitimate traffic. Compliment-ing this, visual analysis facilitates the rapid review and correlation of events, thereby utilizing human intelligence in the identification of scan-ning patterns. To demonstrate the proposed method, several months of network telescope traffic is captured and analysed with a tailor made 3D scatter-plot visualisation. As the results show, the visualisation saliently conveys anomalous patterns, and further analysis reveals that these patterns are indicative of covert network probing activity. By incorporat-ing visual analysis with traditional approaches, such as textual log re-view and the use of an intrusion detection system, this research contrib-utes improved insight into network scanning incidents.
- Full Text:
Identifying needs and opportunities for local government environmental education and training in South Africa
- Olvitt, Lausanne L, Hamaamba, Tyson
- Authors: Olvitt, Lausanne L , Hamaamba, Tyson
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370991 , vital:66400 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122739"
- Description: Effective environmental management and public engagement with environmental concerns are needed for the attainment of sustainable development goals and socio-ecological balance in local government contexts. This vision is clearly articulated in international environmental policy frameworks and in South Africa’s national and regional legislation. However, policy and legislation fall short of identifying the range of a priori competences required by local government officials and environmental managers before well intended policy can be translated into effective practice. This paper reports on recent research into identifying the underlying competences required for better environmental management and the establishment of education and training processes for local government managers. The research draws on the notion of ‘applied competence’ put forward by South Africa’s National Qualifications Framework, and argues that greater attention needs to be paid to competence-based capacity building processes within local government departments if environmental sustainability and development goals are to be met. The paper draws on the researchers’ experiences of formulating a national level generic competence framework for environmental management, and conducting an education and training needs analysis for the Makana Municipality in the Eastern Cape province of South Africa. Early findings suggest that a broad range of competences all have a role in ensuring the capacity and effectiveness of local governments to better manage their local environment. The paper argues that these are significant for the development of environmental education and training programmes in local government contexts.
- Full Text:
- Authors: Olvitt, Lausanne L , Hamaamba, Tyson
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370991 , vital:66400 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122739"
- Description: Effective environmental management and public engagement with environmental concerns are needed for the attainment of sustainable development goals and socio-ecological balance in local government contexts. This vision is clearly articulated in international environmental policy frameworks and in South Africa’s national and regional legislation. However, policy and legislation fall short of identifying the range of a priori competences required by local government officials and environmental managers before well intended policy can be translated into effective practice. This paper reports on recent research into identifying the underlying competences required for better environmental management and the establishment of education and training processes for local government managers. The research draws on the notion of ‘applied competence’ put forward by South Africa’s National Qualifications Framework, and argues that greater attention needs to be paid to competence-based capacity building processes within local government departments if environmental sustainability and development goals are to be met. The paper draws on the researchers’ experiences of formulating a national level generic competence framework for environmental management, and conducting an education and training needs analysis for the Makana Municipality in the Eastern Cape province of South Africa. Early findings suggest that a broad range of competences all have a role in ensuring the capacity and effectiveness of local governments to better manage their local environment. The paper argues that these are significant for the development of environmental education and training programmes in local government contexts.
- 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:
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:
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:
Izaci namaqhalo esiXhosa: Xhosa idioms and proverbs referring to plants
- Cocks, Michelle L, Dold, Anthony P
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141326 , vital:37962 , https://hdl.handle.net/10520/EJC112940
- Description: Converging with the ecological extinction crisis, the planet has been experiencing a severe erosion of the diversity of human cultures and languages, reducing the pool of knowledge, behaviors and values from which individual communities and humanity at large can draw to respond to social and environmental stresses.
- Full Text:
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141326 , vital:37962 , https://hdl.handle.net/10520/EJC112940
- Description: Converging with the ecological extinction crisis, the planet has been experiencing a severe erosion of the diversity of human cultures and languages, reducing the pool of knowledge, behaviors and values from which individual communities and humanity at large can draw to respond to social and environmental stresses.
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JM Coetzee's Disgrace and the Task of the Imagination:
- Authors: Marais, Mike
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144126 , vital:38313 , DOI: 10.2979/JML.2006.29.2.75
- Description: In an early review of Disgrace, Jane Taylor first relates this novel's treatment of violence in post-apartheid South Africa to the European Enlightenment's legacy of the autonomy of the human subject (25), in terms of which each individual is conceived of as a living consciousness separated totally from every other consciousness, and then discusses J.M. Coetzee's postulation of the sympathetic imagination as a potential corrective to the violence attendant on monadic individuality. Taylor makes the telling point that, in the eighteenth century, the notions of sensibility, sympathy, and compassion, which the novel repeatedly invokes, were self-consciously developed as an ethical response to the instrumentalist logic of autonomous individuality and, in this regard, she cites Adam Smith's observation in The Theory of Moral Sentiments that "By the imagination we place ourselves in his situation, we conceive ourselves enduring all the same torments, we enter as it were into his body, and become in some measure the same person with him, and thence form some idea of his sensation" (qtd. in Taylor 25).
- Full Text:
- Authors: Marais, Mike
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144126 , vital:38313 , DOI: 10.2979/JML.2006.29.2.75
- Description: In an early review of Disgrace, Jane Taylor first relates this novel's treatment of violence in post-apartheid South Africa to the European Enlightenment's legacy of the autonomy of the human subject (25), in terms of which each individual is conceived of as a living consciousness separated totally from every other consciousness, and then discusses J.M. Coetzee's postulation of the sympathetic imagination as a potential corrective to the violence attendant on monadic individuality. Taylor makes the telling point that, in the eighteenth century, the notions of sensibility, sympathy, and compassion, which the novel repeatedly invokes, were self-consciously developed as an ethical response to the instrumentalist logic of autonomous individuality and, in this regard, she cites Adam Smith's observation in The Theory of Moral Sentiments that "By the imagination we place ourselves in his situation, we conceive ourselves enduring all the same torments, we enter as it were into his body, and become in some measure the same person with him, and thence form some idea of his sensation" (qtd. in Taylor 25).
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Joking around in Zimbabwe, undoing and redoing participation
- Authors: Price, Leigh
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373715 , vital:66716 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122750"
- Description: In Zimbabwe, I teach a participatory course on environmental education to trainers. The course is an adaptation of a course designed by Rhodes University, South Africa. It gives participants a background in educational theories and has a strong theoretical component built around a focus on practice. During the time that the course was being delivered to non-industry participants, the theoretical component of the course was whole-heartedly embraced. We assumed that calling the course ‘participatory’ presupposed the need for this theory because within the theory were the tools for emancipation. And participation, we believed, had an emancipatory mandate. However, when we decided to redevelop the course for industry, we were uncomfortably surprised by the request from a majority of industry participants to reduce the theory and concentrate solely on skills-based training. This paper documents how this discomfort resulted in my adjusting my view of participation.
- Full Text:
- Authors: Price, Leigh
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373715 , vital:66716 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122750"
- Description: In Zimbabwe, I teach a participatory course on environmental education to trainers. The course is an adaptation of a course designed by Rhodes University, South Africa. It gives participants a background in educational theories and has a strong theoretical component built around a focus on practice. During the time that the course was being delivered to non-industry participants, the theoretical component of the course was whole-heartedly embraced. We assumed that calling the course ‘participatory’ presupposed the need for this theory because within the theory were the tools for emancipation. And participation, we believed, had an emancipatory mandate. However, when we decided to redevelop the course for industry, we were uncomfortably surprised by the request from a majority of industry participants to reduce the theory and concentrate solely on skills-based training. This paper documents how this discomfort resulted in my adjusting my view of participation.
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Labouring to love: romantic love and power in the construction of middle-class femininity
- Vincent, Louise, McEwen, Caryn
- Authors: Vincent, Louise , McEwen, Caryn
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141783 , vital:38004 , DOI: 10.1177/097152150501300102
- Description: South Africa is 10 years into its new democratic order. An aspect of the country's political transformation has been an official political commitment to gender trans-formation. While great strides have been made towards greater gender equality at the institutional and legal level of society, the present article suggests that highly unequal power relations between men and women continue to be perpetuated in unexpected ways among those whom we would most expect to be capable of resistance. This paper is about how subtle yet deeply embedded ideologies and practices within heterosexual relationships serve to keep highly educated, apparently empowered and liberated women ‘in their place’, ensuring that they do not fulfil their potential. Traditionally women were socialised into assuming their positions in the home as caregivers and unpaid household labourers. The hope of feminism was that education, economic empowerment and an ideology of ‘can do’ independence would liberate women. However, for many women, it is in the most intimate aspects of their lives—in their sexual relationships with men—that this hope continues to be thwarted.
- Full Text:
- Authors: Vincent, Louise , McEwen, Caryn
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141783 , vital:38004 , DOI: 10.1177/097152150501300102
- Description: South Africa is 10 years into its new democratic order. An aspect of the country's political transformation has been an official political commitment to gender trans-formation. While great strides have been made towards greater gender equality at the institutional and legal level of society, the present article suggests that highly unequal power relations between men and women continue to be perpetuated in unexpected ways among those whom we would most expect to be capable of resistance. This paper is about how subtle yet deeply embedded ideologies and practices within heterosexual relationships serve to keep highly educated, apparently empowered and liberated women ‘in their place’, ensuring that they do not fulfil their potential. Traditionally women were socialised into assuming their positions in the home as caregivers and unpaid household labourers. The hope of feminism was that education, economic empowerment and an ideology of ‘can do’ independence would liberate women. However, for many women, it is in the most intimate aspects of their lives—in their sexual relationships with men—that this hope continues to be thwarted.
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Learning about participation in integrated water resources management: A South African review
- Burt, Jane, du Toit, Derick, Neves, David, Pollard, Sharon
- Authors: Burt, Jane , du Toit, Derick , Neves, David , Pollard, Sharon
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433025 , vital:72924 , xlink:href="https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT293-06.pdf"
- Description: The National Water Act (1998) opens the way for ordinary people to take part in water resource management (WRM). This is a significant move towards a more social orientation and away from an approach that focused almost exclusively on the technical aspects of WRM. This set of two books asks what a social orientation means in practice. Since the National Water Act became law in 1998, how have WRM practitioners involved people in the process of managing water? What have we learnt so far? And how can we use these lessons to move forward? The content of the books is based on research that looked in some depth at national and local participatory practice in South Africa, and also broadly at international trends. The research was conducted by three WRM practitioners and two researchers in the field of participatory approaches.
- Full Text:
- Authors: Burt, Jane , du Toit, Derick , Neves, David , Pollard, Sharon
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433025 , vital:72924 , xlink:href="https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT293-06.pdf"
- Description: The National Water Act (1998) opens the way for ordinary people to take part in water resource management (WRM). This is a significant move towards a more social orientation and away from an approach that focused almost exclusively on the technical aspects of WRM. This set of two books asks what a social orientation means in practice. Since the National Water Act became law in 1998, how have WRM practitioners involved people in the process of managing water? What have we learnt so far? And how can we use these lessons to move forward? The content of the books is based on research that looked in some depth at national and local participatory practice in South Africa, and also broadly at international trends. The research was conducted by three WRM practitioners and two researchers in the field of participatory approaches.
- Full Text:
Managing South Africa's trawl bycatch
- Walmsley, Sarah A, Leslie, Rob W, Sauer, Warwick H H
- Authors: Walmsley, Sarah A , Leslie, Rob W , Sauer, Warwick H H
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124954 , vital:35713 , https://doi.10.1093/icesjms/fsl022
- Description: Over the past few decades, it has become widely recognized that the management strategies of world fisheries must ensure sustainability of bycatch as well as of target species. South Africa implemented a pilot observer programme from 1995 to 2000 to collect data on the levels and patterns of bycatch and discards in the demersal trawl fishery. Here, the results of that programme are used in conjunction with information on bycatch value and compliance to assess the issues and problems regarding bycatch and discarding in the fishery. In general, bycatch components can be placed into one of three categories (discarded bycatch, retained bycatch, and processing waste), each of which present different management problems and require different management approaches. The results were used to formulate a bycatch management plan for the demersal trawl fishery in South Africa. Given the need to continue monitoring bycatch, the performance of the pilot observer programme is reviewed, and the levels of sampling effort required for a national programme are discussed.
- Full Text:
- Authors: Walmsley, Sarah A , Leslie, Rob W , Sauer, Warwick H H
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124954 , vital:35713 , https://doi.10.1093/icesjms/fsl022
- Description: Over the past few decades, it has become widely recognized that the management strategies of world fisheries must ensure sustainability of bycatch as well as of target species. South Africa implemented a pilot observer programme from 1995 to 2000 to collect data on the levels and patterns of bycatch and discards in the demersal trawl fishery. Here, the results of that programme are used in conjunction with information on bycatch value and compliance to assess the issues and problems regarding bycatch and discarding in the fishery. In general, bycatch components can be placed into one of three categories (discarded bycatch, retained bycatch, and processing waste), each of which present different management problems and require different management approaches. The results were used to formulate a bycatch management plan for the demersal trawl fishery in South Africa. Given the need to continue monitoring bycatch, the performance of the pilot observer programme is reviewed, and the levels of sampling effort required for a national programme are discussed.
- Full Text:
Methinks he doth protest too much - recovering unjustified payments made under duress and protest
- Authors: Glover, Graham B
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70744 , vital:29724 , https://hdl.handle.net/10520/EJC55014
- Description: The private law doctrine of duress, although mostly discussed in the context of the law of contract in South Africa, is also relevant in the law of unjustified enrichment. Where an unjustified payment or transfer of some kind has been induced by duress, in a situation where there is no contractual relationship between the parties, the aggrieved party will be entitled to reclaim the payment or transfer. The principles of enrichment law will apply in such cases.
- Full Text: false
- Authors: Glover, Graham B
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70744 , vital:29724 , https://hdl.handle.net/10520/EJC55014
- Description: The private law doctrine of duress, although mostly discussed in the context of the law of contract in South Africa, is also relevant in the law of unjustified enrichment. Where an unjustified payment or transfer of some kind has been induced by duress, in a situation where there is no contractual relationship between the parties, the aggrieved party will be entitled to reclaim the payment or transfer. The principles of enrichment law will apply in such cases.
- Full Text: false
Mlanjeni's war charms: Ikhubalo likaMlanjeni
- Cocks, Michelle L, Dold, Anthony P
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141349 , vital:37964 , https://hdl.handle.net/10520/EJC112911
- Description: Most South Africans are familiar with lucky charms such as the four leaved clover of European origin, the Hamsa Hand (Arabic) or Hamesh Hand (Hebrew), the Hindu lucky elephant representing Ganesha, son of Siva, or the African ikhubalo. Amakhubalo refer to charms, often of plant origin, that have magical powers to ward off danger or to bring good luck. Charm plants are used almost everywhere in the Eastern Cape to ensure health, luck and success in sporting events, business, courtship, legal proceedings, safety against accidents and crime and protection against jealousy and sorcery.
- Full Text:
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141349 , vital:37964 , https://hdl.handle.net/10520/EJC112911
- Description: Most South Africans are familiar with lucky charms such as the four leaved clover of European origin, the Hamsa Hand (Arabic) or Hamesh Hand (Hebrew), the Hindu lucky elephant representing Ganesha, son of Siva, or the African ikhubalo. Amakhubalo refer to charms, often of plant origin, that have magical powers to ward off danger or to bring good luck. Charm plants are used almost everywhere in the Eastern Cape to ensure health, luck and success in sporting events, business, courtship, legal proceedings, safety against accidents and crime and protection against jealousy and sorcery.
- Full Text:
Monthly Patch Release Schedules: Do the Benefits Outweigh the Risks?
- White, Dominic, Irwin, Barry V W
- Authors: White, Dominic , Irwin, Barry V W
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428749 , vital:72533 , https://www.academia.edu/29214940/A_Unified_Patch_Management_Architecture
- Description: This paper attempts to address the issue of hardening the internal security of an or-ganisation’s network by easing its patch management. A unified architecture to aid with this process is proposed, with the view towards the implementation of an open source, cross platform tool to solve this problem.
- Full Text:
- Authors: White, Dominic , Irwin, Barry V W
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428749 , vital:72533 , https://www.academia.edu/29214940/A_Unified_Patch_Management_Architecture
- Description: This paper attempts to address the issue of hardening the internal security of an or-ganisation’s network by easing its patch management. A unified architecture to aid with this process is proposed, with the view towards the implementation of an open source, cross platform tool to solve this problem.
- Full Text: