Extending the NFComms: framework for bulk data transfers
- Nottingham, Alastair, Irwin, Barry V W
- Authors: Nottingham, Alastair , Irwin, Barry V W
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430164 , vital:72670 , https://doi.org/10.1145/1632149.1632170
- Description: Packet analysis is an important aspect of network security, which typi-cally relies on a flexible packet filtering system to extrapolate important packet information from each processed packet. Packet analysis is a computationally intensive, highly parallelisable task, and as such, clas-sification of large packet sets, such as those collected by a network tel-escope, can require significant processing time. We wish to improve upon this, through parallel classification on a GPU. In this paper, we first consider the OpenCL architecture and its applicability to packet analy-sis. We then introduce a number of packet demultiplexing and routing algorithms, and finally present a discussion on how some of these techniques may be leveraged within a GPGPU context to improve packet classification speeds.
- Full Text:
- Date Issued: 2009
- Authors: Nottingham, Alastair , Irwin, Barry V W
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430164 , vital:72670 , https://doi.org/10.1145/1632149.1632170
- Description: Packet analysis is an important aspect of network security, which typi-cally relies on a flexible packet filtering system to extrapolate important packet information from each processed packet. Packet analysis is a computationally intensive, highly parallelisable task, and as such, clas-sification of large packet sets, such as those collected by a network tel-escope, can require significant processing time. We wish to improve upon this, through parallel classification on a GPU. In this paper, we first consider the OpenCL architecture and its applicability to packet analy-sis. We then introduce a number of packet demultiplexing and routing algorithms, and finally present a discussion on how some of these techniques may be leveraged within a GPGPU context to improve packet classification speeds.
- Full Text:
- Date Issued: 2009
Management, Processing and Analysis of Cryptographic Network Protocols
- Cowie, Bradley, Irwin, Barry V W, Barnett, Richard J
- Authors: Cowie, Bradley , Irwin, Barry V W , Barnett, Richard J
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428687 , vital:72529 , https://d1wqtxts1xzle7.cloudfront.net/30968790/ISSA2009Proceedings-libre.pdf?1393060231=andresponse-content-disposi-tion=inline%3B+filename%3DAN_ANALYSIS_OF_AUTHENTICATION_FOR_PASSIV.pdfandExpires=1714732172andSignature=Ei8RhR2pCSUNGCNE40DugEyFamcyTxPuuRq9gslD~WGlNqPEgG3FL7VFRQCKXhZBWyAfGRjMtBmNDJ7Sjsgex12WxW9Fj8XdpB7Bfz23FuLc-t2YRM-2joKOHJQLxWJlfZiOzxDvVGZeM3zCHj~f3NUeY1~n6PtVtLzNdL8glIg5dzDTTIE6ms2YlxmnO6JvlzQwOWdHaUbHsZzMGOV19UPtBk-UJzHSq3NRyPe4-XNZQLNK-mEEcMGsLk6nkyXIsW2QJ7gtKW1nNkr6EMkAGSOnDai~pSqzb2imspMnlPRigAPPISrNHO79rP51H9bu1WvbRZv1KVkGvM~sRmfl28A__andKey-Pair-Id=APKAJLOHF5GGSLRBV4ZA#page=499
- Description: The use of cryptographic protocols as a means to provide security to web servers and services at the transport layer, by providing both en-cryption and authentication to data transfer, has become increasingly popular. However, we note that it is rather difficult to perform legitimate analysis, intrusion detection and debugging on cryptographic protocols, as the data that passes through is encrypted. In this paper we assume that we have legitimate access to the data and that we have the private key used in transactions and thus we will be able decrypt the data. The objective is to produce a suitable application framework that allows for easy recovery and secure storage of cryptographic keys; including ap-propriate tools to decapsulate traffic and to decrypt live packet streams or precaptured traffic contained in PCAP files. The resultant processing will then be able to provide a clear-text stream which can be used for further analysis.
- Full Text:
- Date Issued: 2009
- Authors: Cowie, Bradley , Irwin, Barry V W , Barnett, Richard J
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428687 , vital:72529 , https://d1wqtxts1xzle7.cloudfront.net/30968790/ISSA2009Proceedings-libre.pdf?1393060231=andresponse-content-disposi-tion=inline%3B+filename%3DAN_ANALYSIS_OF_AUTHENTICATION_FOR_PASSIV.pdfandExpires=1714732172andSignature=Ei8RhR2pCSUNGCNE40DugEyFamcyTxPuuRq9gslD~WGlNqPEgG3FL7VFRQCKXhZBWyAfGRjMtBmNDJ7Sjsgex12WxW9Fj8XdpB7Bfz23FuLc-t2YRM-2joKOHJQLxWJlfZiOzxDvVGZeM3zCHj~f3NUeY1~n6PtVtLzNdL8glIg5dzDTTIE6ms2YlxmnO6JvlzQwOWdHaUbHsZzMGOV19UPtBk-UJzHSq3NRyPe4-XNZQLNK-mEEcMGsLk6nkyXIsW2QJ7gtKW1nNkr6EMkAGSOnDai~pSqzb2imspMnlPRigAPPISrNHO79rP51H9bu1WvbRZv1KVkGvM~sRmfl28A__andKey-Pair-Id=APKAJLOHF5GGSLRBV4ZA#page=499
- Description: The use of cryptographic protocols as a means to provide security to web servers and services at the transport layer, by providing both en-cryption and authentication to data transfer, has become increasingly popular. However, we note that it is rather difficult to perform legitimate analysis, intrusion detection and debugging on cryptographic protocols, as the data that passes through is encrypted. In this paper we assume that we have legitimate access to the data and that we have the private key used in transactions and thus we will be able decrypt the data. The objective is to produce a suitable application framework that allows for easy recovery and secure storage of cryptographic keys; including ap-propriate tools to decapsulate traffic and to decrypt live packet streams or precaptured traffic contained in PCAP files. The resultant processing will then be able to provide a clear-text stream which can be used for further analysis.
- Full Text:
- Date Issued: 2009
NGOs and rural movements in contemporary South Africa
- Authors: Helliker, Kirk D
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71252 , vital:29823 , https://doi.org/10.1080/02533952.2013.806415
- Description: This article provides a critical examination of relationships between non-governmental organisations (NGOs) and rural movements in post-apartheid South Africa, particularly with regard to the possible subordination of movements to NGOs. In discussing NGOs as a particular organisational form, and in reviewing some arguments pertaining to NGOs and rural movements globally, I explore whether NGOs in South Africa have a progressive role to play in agrarian transformation.
- Full Text:
- Date Issued: 2009
- Authors: Helliker, Kirk D
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71252 , vital:29823 , https://doi.org/10.1080/02533952.2013.806415
- Description: This article provides a critical examination of relationships between non-governmental organisations (NGOs) and rural movements in post-apartheid South Africa, particularly with regard to the possible subordination of movements to NGOs. In discussing NGOs as a particular organisational form, and in reviewing some arguments pertaining to NGOs and rural movements globally, I explore whether NGOs in South Africa have a progressive role to play in agrarian transformation.
- Full Text:
- Date Issued: 2009
Quantity and significance of wild meat off-take by a rural community in the Eastern Cape, South Africa
- Kaschula, Sarah A H, Shackleton, Charlie M
- Authors: Kaschula, Sarah A H , Shackleton, Charlie M
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6638 , http://hdl.handle.net/10962/d1006864
- Description: When compared to tropical forest zones in west and central Africa, off-take of wild meat from savannah and grassland biomes by local rural communities has not been well assessed. This case study of wild meat collection activities within a rural community in the Mount Frere region of the Eastern Cape (South Africa) uses last-catch records derived from 50 wild meat gatherers to calculate average off-take of taxa, species and fresh mass of wild meat per collection event. When per-event off take is overlaid onto household hunting frequency data, annual off-take would be 268.6 kg km−2 yr−1 or 3 kg person−1 yr−1 presuming constant off-take over an annual period. Monetary value of off-take would be South African R 307 (US$ 39) per household annually. For some species, off-take weight per km2 shows similar values to data from tropical forest zones, but high human population densities tend to dilute off-takes to less nutritionally significant amounts at the per person scale. However, unlike many tropical zones, none of the species harvested can be considered high-priority conservation species. Even densely populated and heavily harvested communal lands appear to offer high wild meat off-takes from low conservation priority species.
- Full Text:
- Date Issued: 2009
- Authors: Kaschula, Sarah A H , Shackleton, Charlie M
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6638 , http://hdl.handle.net/10962/d1006864
- Description: When compared to tropical forest zones in west and central Africa, off-take of wild meat from savannah and grassland biomes by local rural communities has not been well assessed. This case study of wild meat collection activities within a rural community in the Mount Frere region of the Eastern Cape (South Africa) uses last-catch records derived from 50 wild meat gatherers to calculate average off-take of taxa, species and fresh mass of wild meat per collection event. When per-event off take is overlaid onto household hunting frequency data, annual off-take would be 268.6 kg km−2 yr−1 or 3 kg person−1 yr−1 presuming constant off-take over an annual period. Monetary value of off-take would be South African R 307 (US$ 39) per household annually. For some species, off-take weight per km2 shows similar values to data from tropical forest zones, but high human population densities tend to dilute off-takes to less nutritionally significant amounts at the per person scale. However, unlike many tropical zones, none of the species harvested can be considered high-priority conservation species. Even densely populated and heavily harvested communal lands appear to offer high wild meat off-takes from low conservation priority species.
- Full Text:
- Date Issued: 2009
Rhodes University Library Annual Report 2009: Library Director’s Review
- Authors: Thomas, G M E
- Date: 2009
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/59941 , vital:27713
- Description: [From the Introduction] As you read through this annual overview of the work carried out by the staff of the Rhodes University Library Services Division, I am sure you will be impressed by their achievements during a year marked by major building construction and a demanding institutional review of our services and staffing structures.
- Full Text:
- Date Issued: 2009
- Authors: Thomas, G M E
- Date: 2009
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/59941 , vital:27713
- Description: [From the Introduction] As you read through this annual overview of the work carried out by the staff of the Rhodes University Library Services Division, I am sure you will be impressed by their achievements during a year marked by major building construction and a demanding institutional review of our services and staffing structures.
- Full Text:
- Date Issued: 2009
South African music libraries : collegial, institutional and geographic isolation, an examination
- Authors: Still-Drewett, F
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6984 , http://hdl.handle.net/10962/d1006723
- Description: Music libraries are relatively recent additions to South African library collections and attempts at forming a music library association have been thwarted through a number of financial and historical societal limitations. Consequently, many South African music librarians feel isolated from the field. This paper examines the effects of this isolation and the benefits that closer association for the librarian could bring. Future outlooks for music libraries in South Africa are discussed and suggestions made for a more positive future. Les bibliothèques de musique sont des additions relativement récentes aux collections des bibliothèques en Afrique du sud. Les tentatives de création d'une aßociation de bibliothécaires de musique ont été contrariées pour des raisons financières, historiques et sociales. Par conséquent, beaucoup de bibliothécaires de musique se sentent isolés du milieu. Cet article examine les effets de cette isolation et les bénéfices que pourrait apporter une aßociation qui rapproche les bibliothécaires. Il aborde des discußions sur des perspectives futures et émet des suggestion afin d'appréhender un avenir plus positif. Musikbibliotheken sind eine relativ neue Erscheinung im Bibliothekswesen Südafrikas. Die Gründung einer musikbibliothekarischen Vereinigung ist aus finanziellen und anderen Gründen heraus immer wieder gescheitert. Daher fühlen sich viele südafrikanische Musikbibliothekare beruflich isoliert. Der Artikel untersucht die Auswirkungen dieser Isolation und die Vorteile, die ein engerer Zusammenschluß den Bibliothekaren bringen könnte. Er wagt einen Ausblick in und macht Vorschläge für die Zukunft südafrikanischer Musikbibliotheken.
- Full Text:
- Date Issued: 2009
- Authors: Still-Drewett, F
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6984 , http://hdl.handle.net/10962/d1006723
- Description: Music libraries are relatively recent additions to South African library collections and attempts at forming a music library association have been thwarted through a number of financial and historical societal limitations. Consequently, many South African music librarians feel isolated from the field. This paper examines the effects of this isolation and the benefits that closer association for the librarian could bring. Future outlooks for music libraries in South Africa are discussed and suggestions made for a more positive future. Les bibliothèques de musique sont des additions relativement récentes aux collections des bibliothèques en Afrique du sud. Les tentatives de création d'une aßociation de bibliothécaires de musique ont été contrariées pour des raisons financières, historiques et sociales. Par conséquent, beaucoup de bibliothécaires de musique se sentent isolés du milieu. Cet article examine les effets de cette isolation et les bénéfices que pourrait apporter une aßociation qui rapproche les bibliothécaires. Il aborde des discußions sur des perspectives futures et émet des suggestion afin d'appréhender un avenir plus positif. Musikbibliotheken sind eine relativ neue Erscheinung im Bibliothekswesen Südafrikas. Die Gründung einer musikbibliothekarischen Vereinigung ist aus finanziellen und anderen Gründen heraus immer wieder gescheitert. Daher fühlen sich viele südafrikanische Musikbibliothekare beruflich isoliert. Der Artikel untersucht die Auswirkungen dieser Isolation und die Vorteile, die ein engerer Zusammenschluß den Bibliothekaren bringen könnte. Er wagt einen Ausblick in und macht Vorschläge für die Zukunft südafrikanischer Musikbibliotheken.
- Full Text:
- Date Issued: 2009
A Grid-Based Approach to the Remote Control and Recall of the Properties of IEEE1394 Audio Devices
- Foss, Richard, Foulkes, Phillip
- Authors: Foss, Richard , Foulkes, Phillip
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427212 , vital:72422 , https://www.aes.org/e-lib/browse.cfm?elib=14453
- Description: Typically, the configuration of audio hardware and software is not integrated. This paper discusses a software system that has been developed to remotely control and recall the properties of IEEE1394 (FireWire) audio devices via a series of graphical routing matrices. The software presents sound engineers with a graphical routing matrix that shows, along its axes, the available FireWire audio devices on a FireWire network. Inter device connection management may be performed by selecting the cross points on the grid, and intra device control may be performed via device editors that are displayed via the axes of the matrix. The software application may be hosted by a compatible Digital Audio Workstation (DAW) application to allow for the storing and recalling of the various properties associated with the devices.
- Full Text:
- Date Issued: 2008
- Authors: Foss, Richard , Foulkes, Phillip
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427212 , vital:72422 , https://www.aes.org/e-lib/browse.cfm?elib=14453
- Description: Typically, the configuration of audio hardware and software is not integrated. This paper discusses a software system that has been developed to remotely control and recall the properties of IEEE1394 (FireWire) audio devices via a series of graphical routing matrices. The software presents sound engineers with a graphical routing matrix that shows, along its axes, the available FireWire audio devices on a FireWire network. Inter device connection management may be performed by selecting the cross points on the grid, and intra device control may be performed via device editors that are displayed via the axes of the matrix. The software application may be hosted by a compatible Digital Audio Workstation (DAW) application to allow for the storing and recalling of the various properties associated with the devices.
- Full Text:
- Date Issued: 2008
Application of satellite-derived rainfall estimates to extend water resource simulation modelling in South Africa
- Sawunyama, Tendai, Hughes, Denis A
- Authors: Sawunyama, Tendai , Hughes, Denis A
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:7089 , http://hdl.handle.net/10962/d1012419
- Description: Spatially interpolated rainfall estimates from rain-gauges are widely used as input to hydrological models, but deriving accurate estimates at appropriate space and time scales remain a major problem. In South Africa there has been a gradual decrease in the number of active rain-gauges over time. Satellite-based estimates of spatial rainfall are becoming more readily available and offer a viable substitute. The paper presents the potential of using Climate Prediction Center African daily precipitation climatology (CPCAPC) satellite-based datasets (2001-2006) to drive a Pitman hydrological model which has been calibrated using gauge-based rainfall data (1920-1990). However, if two sources of rainfall data are to be used together, it is necessary to ensure that they are compatible in terms of their statistical properties. A non-linear frequency of exceedance transformation technique was used to correct the satellite data to be more consistent with historical spatial rainfall estimates. The technique generated simulation results for the 2001 to 2006 period that were greatly improved compared to the direct use of the untransformed satellite data. While there remain some further questions about the use of satellite-derived rainfall data in different parts of the country, they do seem to have the potential to contribute to extending water resource modelling into the future.
- Full Text:
- Date Issued: 2008
- Authors: Sawunyama, Tendai , Hughes, Denis A
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:7089 , http://hdl.handle.net/10962/d1012419
- Description: Spatially interpolated rainfall estimates from rain-gauges are widely used as input to hydrological models, but deriving accurate estimates at appropriate space and time scales remain a major problem. In South Africa there has been a gradual decrease in the number of active rain-gauges over time. Satellite-based estimates of spatial rainfall are becoming more readily available and offer a viable substitute. The paper presents the potential of using Climate Prediction Center African daily precipitation climatology (CPCAPC) satellite-based datasets (2001-2006) to drive a Pitman hydrological model which has been calibrated using gauge-based rainfall data (1920-1990). However, if two sources of rainfall data are to be used together, it is necessary to ensure that they are compatible in terms of their statistical properties. A non-linear frequency of exceedance transformation technique was used to correct the satellite data to be more consistent with historical spatial rainfall estimates. The technique generated simulation results for the 2001 to 2006 period that were greatly improved compared to the direct use of the untransformed satellite data. While there remain some further questions about the use of satellite-derived rainfall data in different parts of the country, they do seem to have the potential to contribute to extending water resource modelling into the future.
- Full Text:
- Date Issued: 2008
Enhancing end-user capabilities in high speed audio networks
- Chigwamba, Nyasha, Foss, Richard
- Authors: Chigwamba, Nyasha , Foss, Richard
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427279 , vital:72427 , https://www.aes.org/e-lib/browse.cfm?elib=14266
- Description: Firewire is a digital network technology that can be used to interconnect professional audio equipment, PCs and electronic devices. The Plural Node Architecture splits connection management of firewire audio devices between two nodes, namely an Enabler and a Transporter. The Audio Engineering Society’s SC-02-12-G Task Group has produced an Open Generic Transporter guideline document which describes a generic interface between the Enabler and Transporter. A client-server implementation above the Plural Node Architecture allows connection management of firewire audio devices via TCP/IP. This paper describes enhancements made to connection management applications as a result of additional capabilities revealed by the Open Generic Transporter document.
- Full Text:
- Date Issued: 2008
- Authors: Chigwamba, Nyasha , Foss, Richard
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427279 , vital:72427 , https://www.aes.org/e-lib/browse.cfm?elib=14266
- Description: Firewire is a digital network technology that can be used to interconnect professional audio equipment, PCs and electronic devices. The Plural Node Architecture splits connection management of firewire audio devices between two nodes, namely an Enabler and a Transporter. The Audio Engineering Society’s SC-02-12-G Task Group has produced an Open Generic Transporter guideline document which describes a generic interface between the Enabler and Transporter. A client-server implementation above the Plural Node Architecture allows connection management of firewire audio devices via TCP/IP. This paper describes enhancements made to connection management applications as a result of additional capabilities revealed by the Open Generic Transporter document.
- Full Text:
- Date Issued: 2008
Should active recruitment of health workers from sub-Saharan Africa be viewed as a crime?
- Mills, E J, Schabas, W A, Volmink, J, Walker, Roderick B, Ford, N, Katabira, E, Anema, A, Joffres, M, Cahn, P, Montaner, J
- Authors: Mills, E J , Schabas, W A , Volmink, J , Walker, Roderick B , Ford, N , Katabira, E , Anema, A , Joffres, M , Cahn, P , Montaner, J
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6392 , http://hdl.handle.net/10962/d1006314
- Description: (Conclusion) When the international community permits for-profit companies to actively entice overworked and often underpaid workers away from the most vulnerable populations, it is contributing to the deterioration of essential health-care delivery. Improvement of the health of the world’s poor is a challenge that the international community is failing to adequately address. Current international treaties and commitments are severely compromised if we are unwilling to adhere to their principles and prevent obvious harms to poor people. Clear, enforced regulation is needed to prevent recruitment companies from enticing health workers away from their local work, and developed countries should adequately compensate less-developed countries for the human resources they have lost and continue to lose.
- Full Text:
- Date Issued: 2008
- Authors: Mills, E J , Schabas, W A , Volmink, J , Walker, Roderick B , Ford, N , Katabira, E , Anema, A , Joffres, M , Cahn, P , Montaner, J
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6392 , http://hdl.handle.net/10962/d1006314
- Description: (Conclusion) When the international community permits for-profit companies to actively entice overworked and often underpaid workers away from the most vulnerable populations, it is contributing to the deterioration of essential health-care delivery. Improvement of the health of the world’s poor is a challenge that the international community is failing to adequately address. Current international treaties and commitments are severely compromised if we are unwilling to adhere to their principles and prevent obvious harms to poor people. Clear, enforced regulation is needed to prevent recruitment companies from enticing health workers away from their local work, and developed countries should adequately compensate less-developed countries for the human resources they have lost and continue to lose.
- Full Text:
- Date Issued: 2008
‘Who? what?’: an uninducted view of towards a new psychology of women from post-Apartheid South Africa
- Authors: Macleod, Catriona I
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6251 , http://hdl.handle.net/10962/d1007869 , http://journals.sagepub.com/doi/abs/10.1177/0959353508092088
- Description: From the text: Towards a New Psychology of Women (TPNW) promises a new psychology of “women”. On the cover of the second edition, the Toronto Globe and Mail is cited as acclaiming the book as “nothing short of revolutionary” as it “set out to recognize, re-define and understand the day-to-day experience of women”. But when we take a closer look at these “women” we discover that they are in fact “white”, (for the most part) middle-class women living in heterosexual relationships in a liberal democracy. This kind of exclusionary inclusion, in which the use of the generic term “woman” disguises the normative assumptions made about the race, class, sexual orientation and location of women, replicates the phallocentrism evidenced in the normalising masculinist terms “mankind” or “Man”. By now, of course, these kinds of critiques of “white” Western feminism by African American writers (e.g. Collins, 1999) postcolonial feminists (e.g. Mohanty, 1991), African feminists (e.g. Ogundipe-Leslie, 1994; Mangena, 2003), and queer theorists (e.g. Jackson, 1999) are well known.
- Full Text:
- Date Issued: 2008
- Authors: Macleod, Catriona I
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6251 , http://hdl.handle.net/10962/d1007869 , http://journals.sagepub.com/doi/abs/10.1177/0959353508092088
- Description: From the text: Towards a New Psychology of Women (TPNW) promises a new psychology of “women”. On the cover of the second edition, the Toronto Globe and Mail is cited as acclaiming the book as “nothing short of revolutionary” as it “set out to recognize, re-define and understand the day-to-day experience of women”. But when we take a closer look at these “women” we discover that they are in fact “white”, (for the most part) middle-class women living in heterosexual relationships in a liberal democracy. This kind of exclusionary inclusion, in which the use of the generic term “woman” disguises the normative assumptions made about the race, class, sexual orientation and location of women, replicates the phallocentrism evidenced in the normalising masculinist terms “mankind” or “Man”. By now, of course, these kinds of critiques of “white” Western feminism by African American writers (e.g. Collins, 1999) postcolonial feminists (e.g. Mohanty, 1991), African feminists (e.g. Ogundipe-Leslie, 1994; Mangena, 2003), and queer theorists (e.g. Jackson, 1999) are well known.
- Full Text:
- Date Issued: 2008
An analysis of the influence of question design on learners' approaches to number pattern generalisation tasks:
- Samson, Duncan, Schäfer, Marc
- Authors: Samson, Duncan , Schäfer, Marc
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141026 , vital:37938 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC20890
- Description: This paper reports on a study of the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil-and-paper exercises based on linear generalisation tasks set in both numeric and two-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was analysed and classified into one of seven categories. In addition, a meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The results of this study strongly support the notion that question design can play a critical role in influencing learners' choice of strategy and level of attainment when solving pattern generalisation tasks. An understanding of the importance of appropriate question design has direct pedagogical application within the context of the mathematics classroom.
- Full Text:
- Date Issued: 2007
- Authors: Samson, Duncan , Schäfer, Marc
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141026 , vital:37938 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC20890
- Description: This paper reports on a study of the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil-and-paper exercises based on linear generalisation tasks set in both numeric and two-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was analysed and classified into one of seven categories. In addition, a meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The results of this study strongly support the notion that question design can play a critical role in influencing learners' choice of strategy and level of attainment when solving pattern generalisation tasks. An understanding of the importance of appropriate question design has direct pedagogical application within the context of the mathematics classroom.
- Full Text:
- Date Issued: 2007
An XML-Based Approach to Audio Connection Management
- Foss, Richard, Klinkradt, Bradley
- Authors: Foss, Richard , Klinkradt, Bradley
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427253 , vital:72425 , https://www.aes.org/e-lib/browse.cfm?elib=14115
- Description: An XML-based approach to firewire audio connection management has been developed that allows for the creation of connection management applications using a range of implementation tools. The XML connection management requests flow between a client and server, where the client and server can reside on the same or separate workstations. The server maintains the state of the firewire audio device configuration as well as information about potential users. XML is also used to control user access and booking of devices.
- Full Text:
- Date Issued: 2007
- Authors: Foss, Richard , Klinkradt, Bradley
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427253 , vital:72425 , https://www.aes.org/e-lib/browse.cfm?elib=14115
- Description: An XML-based approach to firewire audio connection management has been developed that allows for the creation of connection management applications using a range of implementation tools. The XML connection management requests flow between a client and server, where the client and server can reside on the same or separate workstations. The server maintains the state of the firewire audio device configuration as well as information about potential users. XML is also used to control user access and booking of devices.
- Full Text:
- Date Issued: 2007
CONSTRUCTION CONFERENCE “DECENT WORK IN THE CONSTRUCTION SECTOR TOWARDS & BEYOND 2010"
- NUM
- Authors: NUM
- Date: 2007
- Subjects: NUM
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/250673 , vital:52037
- Description: The 2010 World Cup is upon us, an event of great socio economic import to South Africa and indeed the African Continent. Not only is South Africa on the pedestal, but so is the African Continent. It is all systems go, so says major role players involved in delivering the 2010 FIFA World Cup to the World. However, we wonder if the same holds true for labour, that we can say it is all systems go, when, on the eve of the infrastructure roll out, we are grappling with issues of how we can stake a claim on behalf of the millions of construction workers that we represent.
- Full Text:
- Date Issued: 2007
- Authors: NUM
- Date: 2007
- Subjects: NUM
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/250673 , vital:52037
- Description: The 2010 World Cup is upon us, an event of great socio economic import to South Africa and indeed the African Continent. Not only is South Africa on the pedestal, but so is the African Continent. It is all systems go, so says major role players involved in delivering the 2010 FIFA World Cup to the World. However, we wonder if the same holds true for labour, that we can say it is all systems go, when, on the eve of the infrastructure roll out, we are grappling with issues of how we can stake a claim on behalf of the millions of construction workers that we represent.
- Full Text:
- Date Issued: 2007
GPS TEC and ionosonde TEC over Grahamstown, South Africa: first comparisons
- McKinnell, Lee-Anne, Opperman, Ben D L, Cilliers, Pierre J
- Authors: McKinnell, Lee-Anne , Opperman, Ben D L , Cilliers, Pierre J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6800 , http://hdl.handle.net/10962/d1004163
- Description: The Grahamstown, South Africa (33.3°S, 26.5°E) ionospheric field station operates a UMass Lowell digital pulse ionospheric sounder (Digisonde) and an Ashtech geodetic grade dual frequency GPS receiver. The GPS receiver is owned by Chief Directorate Surveys and Mapping (CDSM) in Cape Town, forms part of the national TrigNet network and was installed in February 2005. The sampling rates of the GPS receiver and Digisonde were set to 1 s and 15 min, respectively. Data from four continuous months, March–June 2005 inclusive, were considered in this initial investigation. Data available from the Grahamstown GPS receiver was limited, and, therefore, only these 4 months have been considered. Total Electron Content (TEC) values were determined from GPS measurements obtained from satellites passing near vertical (within an 80° elevation) to the station. TEC values were obtained from ionograms recorded at times within 5 min of the near vertical GPS measurement. The GPS derived TEC values are referred to as GTEC and the ionogram derived TEC values as ITEC. Comparisons of GTEC and ITEC values are presented in this paper. The differential clock biases of the GPS satellites and receivers are taken into account. The plasmaspheric contribution to the TEC can be inferred from the results, and confirm findings obtained by other groups. This paper describes the groundwork for a procedure that will allow the validation of GPS derived ionospheric information with ionosonde data. This work will be of interest to the International Reference Ionosphere (IRI) community since GPS receivers are becoming recognised as another source for ionospheric information.
- Full Text:
- Date Issued: 2007
- Authors: McKinnell, Lee-Anne , Opperman, Ben D L , Cilliers, Pierre J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6800 , http://hdl.handle.net/10962/d1004163
- Description: The Grahamstown, South Africa (33.3°S, 26.5°E) ionospheric field station operates a UMass Lowell digital pulse ionospheric sounder (Digisonde) and an Ashtech geodetic grade dual frequency GPS receiver. The GPS receiver is owned by Chief Directorate Surveys and Mapping (CDSM) in Cape Town, forms part of the national TrigNet network and was installed in February 2005. The sampling rates of the GPS receiver and Digisonde were set to 1 s and 15 min, respectively. Data from four continuous months, March–June 2005 inclusive, were considered in this initial investigation. Data available from the Grahamstown GPS receiver was limited, and, therefore, only these 4 months have been considered. Total Electron Content (TEC) values were determined from GPS measurements obtained from satellites passing near vertical (within an 80° elevation) to the station. TEC values were obtained from ionograms recorded at times within 5 min of the near vertical GPS measurement. The GPS derived TEC values are referred to as GTEC and the ionogram derived TEC values as ITEC. Comparisons of GTEC and ITEC values are presented in this paper. The differential clock biases of the GPS satellites and receivers are taken into account. The plasmaspheric contribution to the TEC can be inferred from the results, and confirm findings obtained by other groups. This paper describes the groundwork for a procedure that will allow the validation of GPS derived ionospheric information with ionosonde data. This work will be of interest to the International Reference Ionosphere (IRI) community since GPS receivers are becoming recognised as another source for ionospheric information.
- Full Text:
- Date Issued: 2007
The deployment of an e-commerce platform and related projects in a rural area in South Africa
- Dalvit, Lorenzo, Muyingi, H Hyppolite, Terzoli, Alfredo, Thinyane, Mamello
- Authors: Dalvit, Lorenzo , Muyingi, H Hyppolite , Terzoli, Alfredo , Thinyane, Mamello
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428545 , vital:72519 , https://nru.uncst.go.ug/bitstream/handle/123456789/6552/Information%20Communica-tion%20Technologies%20%20page%20410.pdf?sequence=1andisAllowed=y#page=256
- Description: In our paper we describe the development and deployment of an ecommerce platform in Dwesa, a rural area in the former homeland of Transkei in South Africa. The system is designed to promote tourism and advertise local arts, crafts and music, and it entails a number of re-lated projects. Deployment of infrastructure, technical support, promo-tion of the initiative and teaching of computer literacy take place during monthly visits of approximately one week, and involve young research-ers from two universities (one previously disadvantaged; the other his-torically privileged). This ensures a synergy between technical exper-tise and understanding of the local context. Findings so far emphasise the importance of contextualising the intervention to suit local needs and adjust to the local context. The platform is currently being extended to include e-government, e-learning and e-health capabilities. If proven successful, this model can be exported to similar areas in South africa and in the rest of Africa. This could open up potential opportunities for the still unexplored market for ICT in rural Africa.
- Full Text:
- Date Issued: 2007
- Authors: Dalvit, Lorenzo , Muyingi, H Hyppolite , Terzoli, Alfredo , Thinyane, Mamello
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428545 , vital:72519 , https://nru.uncst.go.ug/bitstream/handle/123456789/6552/Information%20Communica-tion%20Technologies%20%20page%20410.pdf?sequence=1andisAllowed=y#page=256
- Description: In our paper we describe the development and deployment of an ecommerce platform in Dwesa, a rural area in the former homeland of Transkei in South Africa. The system is designed to promote tourism and advertise local arts, crafts and music, and it entails a number of re-lated projects. Deployment of infrastructure, technical support, promo-tion of the initiative and teaching of computer literacy take place during monthly visits of approximately one week, and involve young research-ers from two universities (one previously disadvantaged; the other his-torically privileged). This ensures a synergy between technical exper-tise and understanding of the local context. Findings so far emphasise the importance of contextualising the intervention to suit local needs and adjust to the local context. The platform is currently being extended to include e-government, e-learning and e-health capabilities. If proven successful, this model can be exported to similar areas in South africa and in the rest of Africa. This could open up potential opportunities for the still unexplored market for ICT in rural Africa.
- Full Text:
- Date Issued: 2007
Xylem as well as phloem sustains severe damage due to feeding by the Russian wheat aphid
- Saheed, S A, Liu, Lin, Jonsson, L M V, Botha, Christiaan E J
- Authors: Saheed, S A , Liu, Lin , Jonsson, L M V , Botha, Christiaan E J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6541 , http://hdl.handle.net/10962/d1005983
- Description: Investigation of comparative effects of feeding damage by the Russian wheat aphid (RWA, biotype SA1, Diuraphis noxia Mordvilko) on leaf blades of susceptible and resistant wheat cultivars (Triticum aestivum L. var Betta and Betta-Dn1 respectively) were carried out to establish the level of ultrastructural damage caused by this aphid and the possible limitation of damage induced which could be ascribed to the resistance gene Dn1 over the susceptible cultivar. Ultrastructurally, Betta-Dn1 sustained less damage to the vascular tissue as well as to the mesophyll during the experimental period. Both inter- and intracellular probes resulted in considerable saliva deposition as the aphids probed for suitable feeding sites. Salivary tracks were observed between and within mesophyll, bundle sheath cells as well as the vascular tissue, including the xylem. Disruption of organelles and cytoplasm resulted from cell probing and sheath deposition. Cell and organelle damage was more evident in the non-resistant Betta cultivar. The aphids probed for and fed from thin-walled sieve tubes preferentially. Few thick-walled sieve tubes showed evidence of either aphid probing or feeding-related damage. Saliva was deposited when the aphids probed inter- and intracellularly for feeding sites. The aphids appeared preferentially to probe for and feed from thin-walled sieve tubes, as few thick-walled sieve tubes showed evidence of damage. Vessels, apparently probed for water, contained watery saliva that encased the secondary walls and sealed pit membranes between probed vessels and xylem parenchyma. The xylem probed by the RWA was rendered non-functional, probably contributing to symptoms of leaf roll, chlorosis and necrosis, which were observed within two weeks of infestation in the susceptible Betta cultivar. This damage was limited in the resistant Betta-Dn1 cultivar during the same time frame.
- Full Text:
- Date Issued: 2007
- Authors: Saheed, S A , Liu, Lin , Jonsson, L M V , Botha, Christiaan E J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6541 , http://hdl.handle.net/10962/d1005983
- Description: Investigation of comparative effects of feeding damage by the Russian wheat aphid (RWA, biotype SA1, Diuraphis noxia Mordvilko) on leaf blades of susceptible and resistant wheat cultivars (Triticum aestivum L. var Betta and Betta-Dn1 respectively) were carried out to establish the level of ultrastructural damage caused by this aphid and the possible limitation of damage induced which could be ascribed to the resistance gene Dn1 over the susceptible cultivar. Ultrastructurally, Betta-Dn1 sustained less damage to the vascular tissue as well as to the mesophyll during the experimental period. Both inter- and intracellular probes resulted in considerable saliva deposition as the aphids probed for suitable feeding sites. Salivary tracks were observed between and within mesophyll, bundle sheath cells as well as the vascular tissue, including the xylem. Disruption of organelles and cytoplasm resulted from cell probing and sheath deposition. Cell and organelle damage was more evident in the non-resistant Betta cultivar. The aphids probed for and fed from thin-walled sieve tubes preferentially. Few thick-walled sieve tubes showed evidence of either aphid probing or feeding-related damage. Saliva was deposited when the aphids probed inter- and intracellularly for feeding sites. The aphids appeared preferentially to probe for and feed from thin-walled sieve tubes, as few thick-walled sieve tubes showed evidence of damage. Vessels, apparently probed for water, contained watery saliva that encased the secondary walls and sealed pit membranes between probed vessels and xylem parenchyma. The xylem probed by the RWA was rendered non-functional, probably contributing to symptoms of leaf roll, chlorosis and necrosis, which were observed within two weeks of infestation in the susceptible Betta cultivar. This damage was limited in the resistant Betta-Dn1 cultivar during the same time frame.
- Full Text:
- Date Issued: 2007
Anomalous behaviour of thermoluminescence from quartz: a case of glow peaks from a Nigerian quartz
- Ogundare, F O, Chithambo, Makaiko L, Oniya, E O
- Authors: Ogundare, F O , Chithambo, Makaiko L , Oniya, E O
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6796 , http://hdl.handle.net/10962/d1003922
- Description: Anomalous behaviour displayed by a thermoluminescence (TL) glow peak as radiation dose increases in a Nigerian quartz is presented. The glow curves of the phosphor have four clear glow peaks. The peak temperatures of the first three glow peaks were found to be constant with change in radiation dose at 82, 148 and 200ºC for the sample readout at a heating rate of 1ºCs[superscript (-1)]. The peak temperature of the fourth peak, which is at around 320ºC for a sample irradiated to a dose of 63 Gy and heated at 1ºCs[superscript (-1)], displays anomalous behaviour with increase in dose relative to the first three peaks. The temperature at which this peak occurs increases with dose to about 335ºC for 177 Gy and then decreases thereafter as dose is further increased. The change is explained on the assumption that the peak may be complex consisting of several overlapping first-order glow peaks each with different TL behaviour.
- Full Text:
- Date Issued: 2006
- Authors: Ogundare, F O , Chithambo, Makaiko L , Oniya, E O
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6796 , http://hdl.handle.net/10962/d1003922
- Description: Anomalous behaviour displayed by a thermoluminescence (TL) glow peak as radiation dose increases in a Nigerian quartz is presented. The glow curves of the phosphor have four clear glow peaks. The peak temperatures of the first three glow peaks were found to be constant with change in radiation dose at 82, 148 and 200ºC for the sample readout at a heating rate of 1ºCs[superscript (-1)]. The peak temperature of the fourth peak, which is at around 320ºC for a sample irradiated to a dose of 63 Gy and heated at 1ºCs[superscript (-1)], displays anomalous behaviour with increase in dose relative to the first three peaks. The temperature at which this peak occurs increases with dose to about 335ºC for 177 Gy and then decreases thereafter as dose is further increased. The change is explained on the assumption that the peak may be complex consisting of several overlapping first-order glow peaks each with different TL behaviour.
- Full Text:
- Date Issued: 2006
ATP-sulphurylase: An enzymatic marker for biological sulphate reduction
- Oyekola, Oluwaseun O, Pletschke, Brett I
- Authors: Oyekola, Oluwaseun O , Pletschke, Brett I
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6461 , http://hdl.handle.net/10962/d1005790 , http://dx.doi.org/10.1016/j.soilbio.2006.05.014
- Description: Adenosine triphosphate-sulphurylase (ATPS) plays a major role in dissimilatory sulphate reduction. In this study, the level of ATPS activity was monitored in a time course study using a biosulphidogenic batch bioreactor system. A coincident decrease in ATPS activity with a decline in sulphate concentration and an increase in sulphide concentration as biosulphidogenesis proceeded was observed. Flask studies further showed sulphate to be stimulatory to ATPS, while sulphide proved to be inhibitory. The effect of ions (Ca^(2+), Cl^(−), Fe^(2+) and Zn^(2+)) on the ATPS activity was also investigated. Most of the ions studied (Ca^(2+), Cl^(−) and Fe^(2+)) were stimulatory at lower concentrations (40–120 mg/l) but proved toxic at higher concentrations (>120 mg/l). In contrast, Zn^(2+) was inhibitory even at low concentrations ( 40 mg/l). ATPS may potentially be used as an enzymatic marker for biological sulphate reduction in sulphate-rich wastewaters and natural environments (anaerobic systems such as soils and sediments found in freshwater and marine systems), providing all residual sulphide and interfering ions are removed using a simple preparative step.
- Full Text:
- Date Issued: 2006
- Authors: Oyekola, Oluwaseun O , Pletschke, Brett I
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6461 , http://hdl.handle.net/10962/d1005790 , http://dx.doi.org/10.1016/j.soilbio.2006.05.014
- Description: Adenosine triphosphate-sulphurylase (ATPS) plays a major role in dissimilatory sulphate reduction. In this study, the level of ATPS activity was monitored in a time course study using a biosulphidogenic batch bioreactor system. A coincident decrease in ATPS activity with a decline in sulphate concentration and an increase in sulphide concentration as biosulphidogenesis proceeded was observed. Flask studies further showed sulphate to be stimulatory to ATPS, while sulphide proved to be inhibitory. The effect of ions (Ca^(2+), Cl^(−), Fe^(2+) and Zn^(2+)) on the ATPS activity was also investigated. Most of the ions studied (Ca^(2+), Cl^(−) and Fe^(2+)) were stimulatory at lower concentrations (40–120 mg/l) but proved toxic at higher concentrations (>120 mg/l). In contrast, Zn^(2+) was inhibitory even at low concentrations ( 40 mg/l). ATPS may potentially be used as an enzymatic marker for biological sulphate reduction in sulphate-rich wastewaters and natural environments (anaerobic systems such as soils and sediments found in freshwater and marine systems), providing all residual sulphide and interfering ions are removed using a simple preparative step.
- Full Text:
- Date Issued: 2006
Effects of temperature and salinity on the standard metabolic rate (SMR) of the caridean shrimp Palaemon peringueyi
- Allan, Elizabeth L, Froneman, Pierre W, Hodgson, Alan N
- Authors: Allan, Elizabeth L , Froneman, Pierre W , Hodgson, Alan N
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6831 , http://hdl.handle.net/10962/d1007567
- Description: The standard metabolic rate (SMR) of the caridean shrimp Palaemon peringueyi to changes in temperature (15–30 °C), salinity (0–45‰) and a combination thereof was investigated. The rate of oxygen consumption of the shrimp was determined using a YSI oxygen meter. At a constant salinity of 35‰ the respiration rate of P. peringueyi increased with an increase in temperature and ranged between 0.260 and 0.982 μl O[subscript 2] mg wwt[superscript −1] h[superscript −1]. The Q[subscript 10] value over the temperature range 15–25 °C was estimated at 3.13. At a constant temperature of 15 °C the respiration rate of P. peringueyi also increased with an increase in salinity and ranged between 0.231 and 0.860 μl O[subscript 2] mg wwt[superscript −1] h[superscript −1]. For combination experiments the absence of any significant difference in the respiration rate of P. peringueyi at the four temperatures over the salinity range 15–35‰ suggests that the shrimp is well adapted to inhabiting environments characterised by variations in salinity and temperature such as those encountered within the middle and lower reaches of permanently open estuaries with substantial freshwater inflow. On the other hand, the total mortality of the shrimp recorded at salinities < 5‰ at all four temperatures suggests that the upper distribution of the shrimp may reflect physiological constraints. Similarly, the increase in the respiration rate of the shrimp at the four temperatures at salinities > 35‰ suggests that the shrimp may experience osmotic stress in freshwater deprived permanently open and intermittently open estuaries where hypersaline conditions may develop.
- Full Text:
- Date Issued: 2006
- Authors: Allan, Elizabeth L , Froneman, Pierre W , Hodgson, Alan N
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6831 , http://hdl.handle.net/10962/d1007567
- Description: The standard metabolic rate (SMR) of the caridean shrimp Palaemon peringueyi to changes in temperature (15–30 °C), salinity (0–45‰) and a combination thereof was investigated. The rate of oxygen consumption of the shrimp was determined using a YSI oxygen meter. At a constant salinity of 35‰ the respiration rate of P. peringueyi increased with an increase in temperature and ranged between 0.260 and 0.982 μl O[subscript 2] mg wwt[superscript −1] h[superscript −1]. The Q[subscript 10] value over the temperature range 15–25 °C was estimated at 3.13. At a constant temperature of 15 °C the respiration rate of P. peringueyi also increased with an increase in salinity and ranged between 0.231 and 0.860 μl O[subscript 2] mg wwt[superscript −1] h[superscript −1]. For combination experiments the absence of any significant difference in the respiration rate of P. peringueyi at the four temperatures over the salinity range 15–35‰ suggests that the shrimp is well adapted to inhabiting environments characterised by variations in salinity and temperature such as those encountered within the middle and lower reaches of permanently open estuaries with substantial freshwater inflow. On the other hand, the total mortality of the shrimp recorded at salinities < 5‰ at all four temperatures suggests that the upper distribution of the shrimp may reflect physiological constraints. Similarly, the increase in the respiration rate of the shrimp at the four temperatures at salinities > 35‰ suggests that the shrimp may experience osmotic stress in freshwater deprived permanently open and intermittently open estuaries where hypersaline conditions may develop.
- Full Text:
- Date Issued: 2006