Unitarity constraints on the ratio of shear viscosity to entropy density in higher derivative gravity
- Authors: Brustein, R , Medved, A J M
- Date: 2011
- Language: English
- Type: text , Article
- Identifier: vital:6815 , http://hdl.handle.net/10962/d1004325
- Description: We discuss corrections to the ratio of shear viscosity to entropy density η/s in higher-derivative gravity theories. Generically, these theories contain ghost modes with Planck-scale masses. Motivated by general considerations about unitarity, we propose new boundary conditions for the equations of motion of the graviton perturbations that force the amplitude of the ghosts modes to vanish. We analyze explicitly four-derivative perturbative corrections to Einstein gravity which generically lead to four-derivative equations of motion, compare our choice of boundary conditions to previous proposals and show that, with our new prescription, the ratio η/s remains at the Einstein-gravity value of 1/4π to leading order in the corrections. It is argued that, when the new boundary conditions are imposed on six and higher-derivative equations of motion, η/s can only increase from the Einstein-gravity value. We also recall some general arguments that support the validity of our results to all orders in the strength of the corrections to Einstein gravity. We then discuss the particular case of Gauss-Bonnet gravity, for which the equations of motion are only of two-derivative order and the value of η/s can decrease below 1/4π when treated in a nonperturbative way. Our findings provide further evidence for the validity of the KSS bound for theories that can be viewed as perturbative corrections to Einstein gravity.
- Full Text:
- Date Issued: 2011
- Authors: Brustein, R , Medved, A J M
- Date: 2011
- Language: English
- Type: text , Article
- Identifier: vital:6815 , http://hdl.handle.net/10962/d1004325
- Description: We discuss corrections to the ratio of shear viscosity to entropy density η/s in higher-derivative gravity theories. Generically, these theories contain ghost modes with Planck-scale masses. Motivated by general considerations about unitarity, we propose new boundary conditions for the equations of motion of the graviton perturbations that force the amplitude of the ghosts modes to vanish. We analyze explicitly four-derivative perturbative corrections to Einstein gravity which generically lead to four-derivative equations of motion, compare our choice of boundary conditions to previous proposals and show that, with our new prescription, the ratio η/s remains at the Einstein-gravity value of 1/4π to leading order in the corrections. It is argued that, when the new boundary conditions are imposed on six and higher-derivative equations of motion, η/s can only increase from the Einstein-gravity value. We also recall some general arguments that support the validity of our results to all orders in the strength of the corrections to Einstein gravity. We then discuss the particular case of Gauss-Bonnet gravity, for which the equations of motion are only of two-derivative order and the value of η/s can decrease below 1/4π when treated in a nonperturbative way. Our findings provide further evidence for the validity of the KSS bound for theories that can be viewed as perturbative corrections to Einstein gravity.
- Full Text:
- Date Issued: 2011
United Nations mediation in Africa: a case study of the Bakassi conflict intervention, 2002-2006
- Authors: Kenmoe Nougue, Plamielle
- Date: 2011
- Subjects: United Nations -- Africa , Intervention (International law) -- Case studies , United Nations -- Peacekeeping forces -- Africa -- History , Conflict management -- Africa -- Case studies , Bakasi Peninsula (Cameroon) -- Politics and government -- Case studies
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8186 , http://hdl.handle.net/10948/1431 , United Nations -- Africa , Intervention (International law) -- Case studies , United Nations -- Peacekeeping forces -- Africa -- History , Conflict management -- Africa -- Case studies , Bakasi Peninsula (Cameroon) -- Politics and government -- Case studies
- Description: Just as conflict is part of everyday life, mediation can and is practiced everyday and everywhere. It is a way of reaching decisions in a cooperative, non-hierarchical way, allowing for clear and open communication processes. Conflicts can be resolved in a formal manner through courts, arbitration, ombudspeople, diplomacy and mediation, or an informal manner through friends, colleagues, religious and community leaders, and dialogue. The way in which people resolve their disputes has an impact on how societies and institutions are governed. The war in Bakassi has taken its toll on the people of that area for several years now and has witnessed people from Bakassi facing some of the worst effects of armed conflict known to man. This study investigated the use of international mediation in the management of intractable conflict with a specific case study on the Bakassi peninsula conflict between Cameroon and Nigeria. It focused on the mediation process as a conflict management technique in relation to the international relations theories which has been used as a basis for conflict resolution practices. The researcher conducted a document review, content analysis on selected documents and this was supported by strategic interviews. The findings as well as the researcher‘s recommendations are discussed in the study in order to assist the future work of conflict management specialists and other stakeholders who have devoted their efforts to the recovery of areas emerging from conflict.
- Full Text:
- Date Issued: 2011
- Authors: Kenmoe Nougue, Plamielle
- Date: 2011
- Subjects: United Nations -- Africa , Intervention (International law) -- Case studies , United Nations -- Peacekeeping forces -- Africa -- History , Conflict management -- Africa -- Case studies , Bakasi Peninsula (Cameroon) -- Politics and government -- Case studies
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8186 , http://hdl.handle.net/10948/1431 , United Nations -- Africa , Intervention (International law) -- Case studies , United Nations -- Peacekeeping forces -- Africa -- History , Conflict management -- Africa -- Case studies , Bakasi Peninsula (Cameroon) -- Politics and government -- Case studies
- Description: Just as conflict is part of everyday life, mediation can and is practiced everyday and everywhere. It is a way of reaching decisions in a cooperative, non-hierarchical way, allowing for clear and open communication processes. Conflicts can be resolved in a formal manner through courts, arbitration, ombudspeople, diplomacy and mediation, or an informal manner through friends, colleagues, religious and community leaders, and dialogue. The way in which people resolve their disputes has an impact on how societies and institutions are governed. The war in Bakassi has taken its toll on the people of that area for several years now and has witnessed people from Bakassi facing some of the worst effects of armed conflict known to man. This study investigated the use of international mediation in the management of intractable conflict with a specific case study on the Bakassi peninsula conflict between Cameroon and Nigeria. It focused on the mediation process as a conflict management technique in relation to the international relations theories which has been used as a basis for conflict resolution practices. The researcher conducted a document review, content analysis on selected documents and this was supported by strategic interviews. The findings as well as the researcher‘s recommendations are discussed in the study in order to assist the future work of conflict management specialists and other stakeholders who have devoted their efforts to the recovery of areas emerging from conflict.
- Full Text:
- Date Issued: 2011
Universal approximation properties of feedforward artificial neural networks.
- Authors: Redpath, Stuart Frederick
- Date: 2011
- Subjects: Neural networks (Computer science) , Artificial intelligence -- Biological applications , Functional analysis , Weierstrass-Stone Theorem , Banach-Hahn theorem
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5430 , http://hdl.handle.net/10962/d1015869
- Description: In this thesis we summarise several results in the literature which show the approximation capabilities of multilayer feedforward artificial neural networks. We show that multilayer feedforward artificial neural networks are capable of approximating continuous and measurable functions from Rn to R to any degree of accuracy under certain conditions. In particular making use of the Stone-Weierstrass and Hahn-Banach theorems, we show that a multilayer feedforward artificial neural network can approximate any continuous function to any degree of accuracy, by using either an arbitrary squashing function or any continuous sigmoidal function for activation. Making use of the Stone-Weirstrass Theorem again, we extend these approximation capabilities of multilayer feedforward artificial neural networks to the space of measurable functions under any probability measure.
- Full Text:
- Date Issued: 2011
- Authors: Redpath, Stuart Frederick
- Date: 2011
- Subjects: Neural networks (Computer science) , Artificial intelligence -- Biological applications , Functional analysis , Weierstrass-Stone Theorem , Banach-Hahn theorem
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5430 , http://hdl.handle.net/10962/d1015869
- Description: In this thesis we summarise several results in the literature which show the approximation capabilities of multilayer feedforward artificial neural networks. We show that multilayer feedforward artificial neural networks are capable of approximating continuous and measurable functions from Rn to R to any degree of accuracy under certain conditions. In particular making use of the Stone-Weierstrass and Hahn-Banach theorems, we show that a multilayer feedforward artificial neural network can approximate any continuous function to any degree of accuracy, by using either an arbitrary squashing function or any continuous sigmoidal function for activation. Making use of the Stone-Weirstrass Theorem again, we extend these approximation capabilities of multilayer feedforward artificial neural networks to the space of measurable functions under any probability measure.
- Full Text:
- Date Issued: 2011
Uphononongo lokuchubeka kwezimo zabalinganiswa kwiincwadi ezichongiweyo zedrama zesiXhosa
- Authors: Mvanyashe, Andiswa
- Date: 2011
- Subjects: Xhosa drama , Characters and characteristics in literature
- Language: Xhosa
- Type: Thesis , Masters , MA
- Identifier: vital:8450 , http://hdl.handle.net/10948/1409 , Xhosa drama , Characters and characteristics in literature
- Description: Le ngxoxo iza kuthetha ngengcingane yokuchubeka. Phantsi kwengcingane yokuchubeka kuza kuthi kuxoxwe ngezi zinto ziladelayo: ukuchubeka lungileyo kunye nokuchubeka gwenxa, ubuso (imvakalelo), izaci zokuchubeka, ukuchubeka nesini kunye nokuchubeka namandla okanye igunya. Ezi zihloko zingaphantsi ziza kubonakaliswa phantsi kwecandelo lesibini ukuya kwelesine ze isahluko sesihlanu ibe sesokukuqukumbela. Ukuchubeka kufumaneka phantsi kwezifundo zesoshiyolingwistiki. Ingxoxo iza kuthi iqale icacise ngesoshiyolingwistiki. Ukuchubeka kuphuhla kakuhle xa isithethi sisebenzisa amagama entetho-ntshukumo anje ngokuncoma, ukuhlekisa, ukuxolisa njalo-njalo. Ingxoxo iza kuthi inabe nzulu ngengcingane yentetho-ntshukumo. Iza kuphinda ingene nzulu icacisa igama elinentshukumo ngalinye. Le ngxoxo ithi ijonge kwaye iphendule umbuzo othi ingaba ngoobani abachubekileyo kukho amadoda nabantu ababhinqileyo. Lo mbuzo uthi ukhokhelele ingxoxo ekuxoxeni ngesini. Ingcingane yesini iza kuthi isetyenziswe ekuphenduleni lo mbuzo kwaye iza kucaciswa nzulu. Kuyabonakala okokuba apha ekuchubekeni bakhona abantu abachubeka ngenxa yezizathu ezithile. Izizathu ezifana nokuthobela amagunya, ukoyika lo mntu athetha naye, ukuhlonipha njalo-njalo.
- Full Text:
- Date Issued: 2011
- Authors: Mvanyashe, Andiswa
- Date: 2011
- Subjects: Xhosa drama , Characters and characteristics in literature
- Language: Xhosa
- Type: Thesis , Masters , MA
- Identifier: vital:8450 , http://hdl.handle.net/10948/1409 , Xhosa drama , Characters and characteristics in literature
- Description: Le ngxoxo iza kuthetha ngengcingane yokuchubeka. Phantsi kwengcingane yokuchubeka kuza kuthi kuxoxwe ngezi zinto ziladelayo: ukuchubeka lungileyo kunye nokuchubeka gwenxa, ubuso (imvakalelo), izaci zokuchubeka, ukuchubeka nesini kunye nokuchubeka namandla okanye igunya. Ezi zihloko zingaphantsi ziza kubonakaliswa phantsi kwecandelo lesibini ukuya kwelesine ze isahluko sesihlanu ibe sesokukuqukumbela. Ukuchubeka kufumaneka phantsi kwezifundo zesoshiyolingwistiki. Ingxoxo iza kuthi iqale icacise ngesoshiyolingwistiki. Ukuchubeka kuphuhla kakuhle xa isithethi sisebenzisa amagama entetho-ntshukumo anje ngokuncoma, ukuhlekisa, ukuxolisa njalo-njalo. Ingxoxo iza kuthi inabe nzulu ngengcingane yentetho-ntshukumo. Iza kuphinda ingene nzulu icacisa igama elinentshukumo ngalinye. Le ngxoxo ithi ijonge kwaye iphendule umbuzo othi ingaba ngoobani abachubekileyo kukho amadoda nabantu ababhinqileyo. Lo mbuzo uthi ukhokhelele ingxoxo ekuxoxeni ngesini. Ingcingane yesini iza kuthi isetyenziswe ekuphenduleni lo mbuzo kwaye iza kucaciswa nzulu. Kuyabonakala okokuba apha ekuchubekeni bakhona abantu abachubeka ngenxa yezizathu ezithile. Izizathu ezifana nokuthobela amagunya, ukoyika lo mntu athetha naye, ukuhlonipha njalo-njalo.
- Full Text:
- Date Issued: 2011
Uphononongo nzulu lokusetyenziswa kolwimi olucengayo ngabalinganiswa kwincwadi ka Z.S. Qangule ethi, "Amaza" neka A.M. Mmango ethi, "Udike noCikizwa"
- Authors: Notshe, Lwandlekazi
- Date: 2011
- Subjects: Xhosa drama , Figures of speech , Persuasion (Psychology) in literature
- Language: Xhosa
- Type: Thesis , Masters , MA
- Identifier: vital:8476 , http://hdl.handle.net/10948/d1012684 , Xhosa drama , Figures of speech , Persuasion (Psychology) in literature
- Description: Olu phando luza kuphendla ubugcisa bokusetyenziswa kwezicengo ekutshintsheni izimvo, iinkolo nokuziphatha kwabantu. Kuza kugxilwa kakhulu kwiinjongo noxinzelelo lwazo kuba zingunozala wezicengo. Kuza kugocwagocwa ‘Amaza’ kaQangule kwakunye no ‘UDike noCikizwa’ kaMmango. Apha kwezi ncwadi kuza kuhlutywa ukuba ulwimi olucengayo luyasetyenziswa ngabantu abantetho isisiXhosa, nokuba imingangatho eyinqobo (values), inkcubeko, nengqeqesho (socialization) zidlala indima enkulu kulwimi olucengayo. Isahluko sokuqala salo msebenzi siza kunika amagqabantshintshi ngolu phando. Esi sahluko siqulathe: Intshayelelo; Iingxaki zophando; Iinjongo zophando; Ukubaluleka kolu phando; Okusele kubhaliwe ngezicengo; Ingcaciso magama. Isahluko sesibini siqulathe iingcingane zolwimi olucengayo, abasunguli bazo, nemisebenzi yabo. Isahluko sesithathu siqwalasele ukusetyenziswa kwezicengo kwiincwadi ezichongiweyo. Isahluko sesine sijonge ubugcisa bokusetyenziswa kolwimi olucengayo kwizihlobo nakwiintsapho. Kwalapha, kujongwe nokusetyenziswa kolwimi oluchubekileyo ngamadoda nabafazi, igunya, umyalezo ocalanye kwakunye nokunikezela. Isahluko sesihlanu nesisesokugqibela – sishwankathela iziphumo zophando kukwanikwa neengcebiso.
- Full Text:
- Date Issued: 2011
- Authors: Notshe, Lwandlekazi
- Date: 2011
- Subjects: Xhosa drama , Figures of speech , Persuasion (Psychology) in literature
- Language: Xhosa
- Type: Thesis , Masters , MA
- Identifier: vital:8476 , http://hdl.handle.net/10948/d1012684 , Xhosa drama , Figures of speech , Persuasion (Psychology) in literature
- Description: Olu phando luza kuphendla ubugcisa bokusetyenziswa kwezicengo ekutshintsheni izimvo, iinkolo nokuziphatha kwabantu. Kuza kugxilwa kakhulu kwiinjongo noxinzelelo lwazo kuba zingunozala wezicengo. Kuza kugocwagocwa ‘Amaza’ kaQangule kwakunye no ‘UDike noCikizwa’ kaMmango. Apha kwezi ncwadi kuza kuhlutywa ukuba ulwimi olucengayo luyasetyenziswa ngabantu abantetho isisiXhosa, nokuba imingangatho eyinqobo (values), inkcubeko, nengqeqesho (socialization) zidlala indima enkulu kulwimi olucengayo. Isahluko sokuqala salo msebenzi siza kunika amagqabantshintshi ngolu phando. Esi sahluko siqulathe: Intshayelelo; Iingxaki zophando; Iinjongo zophando; Ukubaluleka kolu phando; Okusele kubhaliwe ngezicengo; Ingcaciso magama. Isahluko sesibini siqulathe iingcingane zolwimi olucengayo, abasunguli bazo, nemisebenzi yabo. Isahluko sesithathu siqwalasele ukusetyenziswa kwezicengo kwiincwadi ezichongiweyo. Isahluko sesine sijonge ubugcisa bokusetyenziswa kolwimi olucengayo kwizihlobo nakwiintsapho. Kwalapha, kujongwe nokusetyenziswa kolwimi oluchubekileyo ngamadoda nabafazi, igunya, umyalezo ocalanye kwakunye nokunikezela. Isahluko sesihlanu nesisesokugqibela – sishwankathela iziphumo zophando kukwanikwa neengcebiso.
- Full Text:
- Date Issued: 2011
Use and users of municipal commonage around three small towns in the Eastern Cape, South Africa
- Davenport, Nicholas A, Shackleton, Charlie M, Gambiza, James
- Authors: Davenport, Nicholas A , Shackleton, Charlie M , Gambiza, James
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181116 , vital:43700 , xlink:href="https://doi.org/10.1016/j.jenvman.2010.11.003"
- Description: Municipal commonages surround many small towns throughout South Africa, and are an integral component of the national land reform programme. But little is known about their extent, use or value, and most appear to have limited or no management or investment. This paper reports on a survey of randomly selected households in three small towns in the Eastern Cape to ascertain the extent and purpose of use of municipal commonages. Between 27% and 70% of urban households used commonage depending on site. Key resources used were fuelwood, medicinal plants, and grazing of livestock. Typically, commonage using households were poorer and less educated than other urban residents, although the profile of users is unique for each town. Given the extensive use of commonage resources, and their contribution to the livelihoods of the poor, local municipalities need to develop and implement sound management strategies that account for all users of commonages, rather than the oft encountered focus on livestock owners and production.
- Full Text:
- Date Issued: 2011
- Authors: Davenport, Nicholas A , Shackleton, Charlie M , Gambiza, James
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181116 , vital:43700 , xlink:href="https://doi.org/10.1016/j.jenvman.2010.11.003"
- Description: Municipal commonages surround many small towns throughout South Africa, and are an integral component of the national land reform programme. But little is known about their extent, use or value, and most appear to have limited or no management or investment. This paper reports on a survey of randomly selected households in three small towns in the Eastern Cape to ascertain the extent and purpose of use of municipal commonages. Between 27% and 70% of urban households used commonage depending on site. Key resources used were fuelwood, medicinal plants, and grazing of livestock. Typically, commonage using households were poorer and less educated than other urban residents, although the profile of users is unique for each town. Given the extensive use of commonage resources, and their contribution to the livelihoods of the poor, local municipalities need to develop and implement sound management strategies that account for all users of commonages, rather than the oft encountered focus on livestock owners and production.
- Full Text:
- Date Issued: 2011
User satisfaction in academic libraries: a case study at Walter Sisulu University, Ibika Campus
- Authors: Cingo, Sindiswa
- Date: 2011
- Subjects: User satisfaction -- Academic libraries
- Language: English
- Type: Thesis , Masters , M Bibl
- Identifier: vital:18419 , http://hdl.handle.net/11260/d1006642
- Description: User satisfaction and library use are multidimensional concepts. The scope of every library as a service institution is to provide satisfaction to its users and to strive continuously for their betterment. The aim of this study is, therefore, to determine the satisfaction of users with library services at the circulation desk at Walter Sisulu University (WSU), Ibika Campus. The specific objectives of the study are as follows: To determine the levels of satisfaction of users, especially at the circulation desk; to determine the reasons for any dissatisfaction expressed by the users; to determine the use of databases by the users, and to determine how the Ibika Campus library is rated in general. In this study, a survey was used to determine the levels of satisfaction of users with library services. Questionnaires were distributed to hundred and twenty users, and ninety users responded to these. From the findings, it was clear that most of the respondents were in general satisfied with the library services at WSU, Ibika Campus. Dissatisfaction was expressed by approximately twenty percent of the respondents, because of various reasons which include library opening hours, noise level, temperature, photocopying facilities, the accuracy of the searches, including the use of OPAC. There were also some suggestions from the respondents that entail more staffing, training, expansion of the library building, twenty-four hour reading room facilities and more cubicles for senior students and staff. The expansion of the library building may reduce the noise level because there will be more space, and that will limit group discussions inside the library. Group discussions will be done outside the library in the suggested twenty-four hours reading room. In one of the recommendations, it is suggested that library management should provide ongoing training for all library staff. This will result in enhancement of services. The training will assist the circulation staff to possess excellent interpersonal skills together with a strong service orientation. Lastly, further research needs to be done on library satisfaction in terms of the problems that have been identified, for example, extension of the library building.
- Full Text:
- Date Issued: 2011
- Authors: Cingo, Sindiswa
- Date: 2011
- Subjects: User satisfaction -- Academic libraries
- Language: English
- Type: Thesis , Masters , M Bibl
- Identifier: vital:18419 , http://hdl.handle.net/11260/d1006642
- Description: User satisfaction and library use are multidimensional concepts. The scope of every library as a service institution is to provide satisfaction to its users and to strive continuously for their betterment. The aim of this study is, therefore, to determine the satisfaction of users with library services at the circulation desk at Walter Sisulu University (WSU), Ibika Campus. The specific objectives of the study are as follows: To determine the levels of satisfaction of users, especially at the circulation desk; to determine the reasons for any dissatisfaction expressed by the users; to determine the use of databases by the users, and to determine how the Ibika Campus library is rated in general. In this study, a survey was used to determine the levels of satisfaction of users with library services. Questionnaires were distributed to hundred and twenty users, and ninety users responded to these. From the findings, it was clear that most of the respondents were in general satisfied with the library services at WSU, Ibika Campus. Dissatisfaction was expressed by approximately twenty percent of the respondents, because of various reasons which include library opening hours, noise level, temperature, photocopying facilities, the accuracy of the searches, including the use of OPAC. There were also some suggestions from the respondents that entail more staffing, training, expansion of the library building, twenty-four hour reading room facilities and more cubicles for senior students and staff. The expansion of the library building may reduce the noise level because there will be more space, and that will limit group discussions inside the library. Group discussions will be done outside the library in the suggested twenty-four hours reading room. In one of the recommendations, it is suggested that library management should provide ongoing training for all library staff. This will result in enhancement of services. The training will assist the circulation staff to possess excellent interpersonal skills together with a strong service orientation. Lastly, further research needs to be done on library satisfaction in terms of the problems that have been identified, for example, extension of the library building.
- Full Text:
- Date Issued: 2011
User-interface evaluation metrics for a typical M-Learning application
- Authors: Kantore, Adelin
- Date: 2011
- Subjects: User interfaces (Computer systems) , Mobile communication systems
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9749 , http://hdl.handle.net/10948/1452 , User interfaces (Computer systems) , Mobile communication systems
- Description: Usability is seen as an important aspect for the quality of an M-learning application. Yet very little research has been conducted in this area – particularly in South Africa. Even though the trials of M-learning projects have been witnessed in the country during the last five years, very little is known about the systems that were implemented as regards their usability. Additionally, metrics and measures used in evaluating usability have not been reported. A need exists for relevant metrics to M-learning usability. The primary objective of this work was to propose metrics and measures – for the purpose of evaluating the User-Interfacedesign usability of M-learning application. The research included a literature review of M-learning, as well as the development of metrics and measures based on the Goal Question Metric (GQM) Model. This model has helped provide a reference model and measurements for evaluating the User-InterfaceUsability. A case study was used as a research strategy. An application called Kontax was selected for evaluation by users and expert reviewers. Data-collection methods consisted of User Testing and Heuristics evaluations. Data-gathering instruments included the use of surveys and user- satisfaction questionnaires based on the proposed metrics, task scenarios and expert-reviewed questionnaires based on the proposed metrics; all these instruments were developed. It was found that, although the users thought the system was very interesting, and they wished to hear more about it in the future, the system nevertheless had usability flaws which made it difficult to use. All the users failed to register so that they could use the system; additionally, the system-error messages did not help the users recognize, and recover from an error – leaving the user to simply log out. Help was not adequate, thus making it difficult for first-time users to know what to do when they needed support. The system was also said to have a lot of information presented on its home page, which caused the user to be disoriented. The Kontax application has usability flaws which should be III attended to, in order to improve its usability. The proposed metrics proved to be very useful in evaluating the usability of the tool.
- Full Text:
- Date Issued: 2011
- Authors: Kantore, Adelin
- Date: 2011
- Subjects: User interfaces (Computer systems) , Mobile communication systems
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9749 , http://hdl.handle.net/10948/1452 , User interfaces (Computer systems) , Mobile communication systems
- Description: Usability is seen as an important aspect for the quality of an M-learning application. Yet very little research has been conducted in this area – particularly in South Africa. Even though the trials of M-learning projects have been witnessed in the country during the last five years, very little is known about the systems that were implemented as regards their usability. Additionally, metrics and measures used in evaluating usability have not been reported. A need exists for relevant metrics to M-learning usability. The primary objective of this work was to propose metrics and measures – for the purpose of evaluating the User-Interfacedesign usability of M-learning application. The research included a literature review of M-learning, as well as the development of metrics and measures based on the Goal Question Metric (GQM) Model. This model has helped provide a reference model and measurements for evaluating the User-InterfaceUsability. A case study was used as a research strategy. An application called Kontax was selected for evaluation by users and expert reviewers. Data-collection methods consisted of User Testing and Heuristics evaluations. Data-gathering instruments included the use of surveys and user- satisfaction questionnaires based on the proposed metrics, task scenarios and expert-reviewed questionnaires based on the proposed metrics; all these instruments were developed. It was found that, although the users thought the system was very interesting, and they wished to hear more about it in the future, the system nevertheless had usability flaws which made it difficult to use. All the users failed to register so that they could use the system; additionally, the system-error messages did not help the users recognize, and recover from an error – leaving the user to simply log out. Help was not adequate, thus making it difficult for first-time users to know what to do when they needed support. The system was also said to have a lot of information presented on its home page, which caused the user to be disoriented. The Kontax application has usability flaws which should be III attended to, in order to improve its usability. The proposed metrics proved to be very useful in evaluating the usability of the tool.
- Full Text:
- Date Issued: 2011
Using information visualization techniques to support web service discovery
- Authors: Beets, Simone
- Date: 2011
- Subjects: Information visualization , Web services , Information visualization -- Computer programs
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10457 , http://hdl.handle.net/10948/1659 , Information visualization , Web services , Information visualization -- Computer programs
- Description: The increasing number of web services published over the Web highlights the need for an effective method for users to find appropriate web services. Existing web service discovery methods do not effectively aid a user in finding suitable web services. The current methods provide textual lists of web services that the user is required to explore and manually evaluate. Thus, these methods lead to time-consuming and ineffective web service discovery. The aim of this research was to investigate using information visualization (IV) techniques to effectively support web service discovery. The node-and-link network IV technique was selected as the most appropriate IV technique to visualize web service collections. A prototype, called SerViz, was developed as a tool for interactive visualization of web service collections incorporating the node-and-link IV technique and an alphabetical list-based technique. SerViz used the Programmable Web web service collection as the sample web service collection. A usability evaluation was conducted to compare these techniques. Ninety percent of participants preferred the network IV technique for visualizing web service collections. The network IV technique was also faster for browsing. Several usability problems were identified with the network IV technique. This motivated a need for implementing an alternative IV technique in SerViz. The node-and-link tree IV technique was selected as it was more structured than the network IV technique. A usability evaluation was conducted to compare the network and tree IV techniques. Participants slightly preferred the tree IV technique as the technique to visualize web service collections. The tree IV technique was faster for browsing the web service collection while the network IV technique was faster for searching and filtering. This research has determined that IV techniques can be used to effectively support web service discovery. Future work will involve using IV techniques to support collaborative web service discovery. Keywords: Web Service Discovery, Information Visualization, Web Service Collections, Information Visualization Techniques.
- Full Text:
- Date Issued: 2011
- Authors: Beets, Simone
- Date: 2011
- Subjects: Information visualization , Web services , Information visualization -- Computer programs
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10457 , http://hdl.handle.net/10948/1659 , Information visualization , Web services , Information visualization -- Computer programs
- Description: The increasing number of web services published over the Web highlights the need for an effective method for users to find appropriate web services. Existing web service discovery methods do not effectively aid a user in finding suitable web services. The current methods provide textual lists of web services that the user is required to explore and manually evaluate. Thus, these methods lead to time-consuming and ineffective web service discovery. The aim of this research was to investigate using information visualization (IV) techniques to effectively support web service discovery. The node-and-link network IV technique was selected as the most appropriate IV technique to visualize web service collections. A prototype, called SerViz, was developed as a tool for interactive visualization of web service collections incorporating the node-and-link IV technique and an alphabetical list-based technique. SerViz used the Programmable Web web service collection as the sample web service collection. A usability evaluation was conducted to compare these techniques. Ninety percent of participants preferred the network IV technique for visualizing web service collections. The network IV technique was also faster for browsing. Several usability problems were identified with the network IV technique. This motivated a need for implementing an alternative IV technique in SerViz. The node-and-link tree IV technique was selected as it was more structured than the network IV technique. A usability evaluation was conducted to compare the network and tree IV techniques. Participants slightly preferred the tree IV technique as the technique to visualize web service collections. The tree IV technique was faster for browsing the web service collection while the network IV technique was faster for searching and filtering. This research has determined that IV techniques can be used to effectively support web service discovery. Future work will involve using IV techniques to support collaborative web service discovery. Keywords: Web Service Discovery, Information Visualization, Web Service Collections, Information Visualization Techniques.
- Full Text:
- Date Issued: 2011
Using molecules and morphology to infer the phylogenetic relationships and evolutionary history of the Dirini (Nymphalidae: Satyrinae), a tribe of butterflies endemic to Southern Africa
- Price, Benjamin W, Villet, Martin H, Walton, Shaun M, Barker, Nigel P
- Authors: Price, Benjamin W , Villet, Martin H , Walton, Shaun M , Barker, Nigel P
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442397 , vital:73981 , https://doi.org/10.1111/j.1365-3113.2010.00560.x
- Description: The first empirically supported phylogenetic hypothesis of relationships for the southern African endemic butterfly tribe Dirini is presented. Data derived from the morphology and ecology of the adults and immature stages (33 characters), and portions of the mitochondrial gene cytochrome oxidase I (COI) and the nuclear genes elongation factor 1α (EF1α) and wingless (WG) (totalling 1734 bp) were used to infer the relationships of the in‐group genera. An expanded molecular dataset using four genera from the Nymphalini and Satyrini to root the tree, and three genera from the Melanitini to test the monophyly of the tribe, was analysed using parsimony and Bayesian methods. Estimates of divergence times were calculated using two fossil calibrations under a relaxed molecular clock model. The monophyly of the tribe and each in‐group genus were strongly supported. Key findings are the sister‐taxon relationship of Aeropetes and Tarsocera, the apparent simultaneous or nearly simultaneous radiation of four lineages, the polyphyly of the species within Torynesis, and the apparent trans‐Atlantic dispersal of the ancestors of Manataria about 40 Ma. Estimates of divergence times indicate that the tribe has undergone two major radiations since its origin: the first when they left forest habitats in the mid–late Oligocene, shortly after the radiation of the grasses (Poaceae), and the second in the early‐middle Pliocene, coinciding with the aridification of southern Africa and the spread of conditions that favoured C4 grasses over the C3 grasses that dirine larvae prefer to eat. The high species diversity within the tribe appears to be partly a taxonomic artefact that may have resulted from the misinterpretation of climate-related phenotypic variation within extant species. Relocation and breeding experiments should test this hypothesis.
- Full Text:
- Date Issued: 2011
- Authors: Price, Benjamin W , Villet, Martin H , Walton, Shaun M , Barker, Nigel P
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442397 , vital:73981 , https://doi.org/10.1111/j.1365-3113.2010.00560.x
- Description: The first empirically supported phylogenetic hypothesis of relationships for the southern African endemic butterfly tribe Dirini is presented. Data derived from the morphology and ecology of the adults and immature stages (33 characters), and portions of the mitochondrial gene cytochrome oxidase I (COI) and the nuclear genes elongation factor 1α (EF1α) and wingless (WG) (totalling 1734 bp) were used to infer the relationships of the in‐group genera. An expanded molecular dataset using four genera from the Nymphalini and Satyrini to root the tree, and three genera from the Melanitini to test the monophyly of the tribe, was analysed using parsimony and Bayesian methods. Estimates of divergence times were calculated using two fossil calibrations under a relaxed molecular clock model. The monophyly of the tribe and each in‐group genus were strongly supported. Key findings are the sister‐taxon relationship of Aeropetes and Tarsocera, the apparent simultaneous or nearly simultaneous radiation of four lineages, the polyphyly of the species within Torynesis, and the apparent trans‐Atlantic dispersal of the ancestors of Manataria about 40 Ma. Estimates of divergence times indicate that the tribe has undergone two major radiations since its origin: the first when they left forest habitats in the mid–late Oligocene, shortly after the radiation of the grasses (Poaceae), and the second in the early‐middle Pliocene, coinciding with the aridification of southern Africa and the spread of conditions that favoured C4 grasses over the C3 grasses that dirine larvae prefer to eat. The high species diversity within the tribe appears to be partly a taxonomic artefact that may have resulted from the misinterpretation of climate-related phenotypic variation within extant species. Relocation and breeding experiments should test this hypothesis.
- Full Text:
- Date Issued: 2011
Using multi-touch interaction techniques to support Collaborative Information Retrieval
- Authors: Sams, Ivan
- Date: 2011
- Subjects: Human-computer interaction , Teams in the workplace -- Data processing , Groupware (Computer software) , Interactive computer systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10491 , http://hdl.handle.net/10948/d1020156
- Description: Collaborative Information Retrieval (CIR) is a branch of Computer Supported Cooperative Work (CSCW). CIR is the process by which people search for and retrieve information, working together and using documents as data sources. Currently, computer support for CIR is limited to single user systems. Collaboration takes place either with users working at different times or in different locations. Multi-touch interaction has recently seen a rise in prominence owing to a reduction in the cost of the technology and increased frequency of use. Multi-touch surface computing allows multiple users to interact at once around a shared display. The aim of this research was to investigate how multi-touch interaction techniques could be used to support CIR effectively in a co-located environment. An application architecture for CIR systems that incorporates multi-touch interaction techniques was proposed. A prototype, called Co-IMBRA, was developed based on this architecture that used multi-touch interaction techniques to support CIR. This prototype allows multiple users to retrieve information, using the Internet as a shared information space. Documents are represented as visual objects that can be manipulated on the multi-touch surface, as well as rated, annotated and added to folders. A user study was undertaken to evaluate Co-IMBRA and determine whether the multi-touch interaction techniques effectively supported CIR. Fifteen teams of two users each participated in the user study. High task completion rates and low task times showed that the system was effective and efficient. High levels of user satisfaction were reported in the post-test questionnaires. Participants rated the system as highly useful and several commented that it promoted collaboration and that they enjoyed the test. The successful implementation of Co-IMBRA provides evidence that multi-touch interaction techniques can effectively support CIR. The results of the user evaluation also enabled recommendations for future research to be made.
- Full Text:
- Date Issued: 2011
- Authors: Sams, Ivan
- Date: 2011
- Subjects: Human-computer interaction , Teams in the workplace -- Data processing , Groupware (Computer software) , Interactive computer systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10491 , http://hdl.handle.net/10948/d1020156
- Description: Collaborative Information Retrieval (CIR) is a branch of Computer Supported Cooperative Work (CSCW). CIR is the process by which people search for and retrieve information, working together and using documents as data sources. Currently, computer support for CIR is limited to single user systems. Collaboration takes place either with users working at different times or in different locations. Multi-touch interaction has recently seen a rise in prominence owing to a reduction in the cost of the technology and increased frequency of use. Multi-touch surface computing allows multiple users to interact at once around a shared display. The aim of this research was to investigate how multi-touch interaction techniques could be used to support CIR effectively in a co-located environment. An application architecture for CIR systems that incorporates multi-touch interaction techniques was proposed. A prototype, called Co-IMBRA, was developed based on this architecture that used multi-touch interaction techniques to support CIR. This prototype allows multiple users to retrieve information, using the Internet as a shared information space. Documents are represented as visual objects that can be manipulated on the multi-touch surface, as well as rated, annotated and added to folders. A user study was undertaken to evaluate Co-IMBRA and determine whether the multi-touch interaction techniques effectively supported CIR. Fifteen teams of two users each participated in the user study. High task completion rates and low task times showed that the system was effective and efficient. High levels of user satisfaction were reported in the post-test questionnaires. Participants rated the system as highly useful and several commented that it promoted collaboration and that they enjoyed the test. The successful implementation of Co-IMBRA provides evidence that multi-touch interaction techniques can effectively support CIR. The results of the user evaluation also enabled recommendations for future research to be made.
- Full Text:
- Date Issued: 2011
Using social marketing to bridge the gap between systematic conservation planning and implementation at the local government level
- Authors: Wilhelm-Rechmann, Angelika
- Date: 2011
- Subjects: Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10603 , http://hdl.handle.net/10948/1550 , Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Description: The study presented here describes an attempt to bridge the gap between systematic conservation assessment and decision-making for land-use planning in the Eastern Cape province, South Africa. The aim was to investigate how to effectively convince officials concerned with land use planning processes in the local municipal sphere to include conservation priorities meaningfully in their processes. The approach used to reach this aim was social marketing, the use of marketing technologies and concepts to effect behavior changes to further societal good. So far social marketing is not commonly used in the conservation domain; I therefore aimed also at proving the usefulness of this approach for conservation. Following the introduction which provides background to the project and a more detailed summary, Chapter 2 provides a detailed and comprehensive review of the considerations and concepts regarding the use of social marketing in a context geared at protecting nature. The research on the primary target group for this study, officials concerned with land use planning processes in the local municipal sphere is described in Chapter 3. The main outcomes were that land use planners perceive few needs with regards to implementing the incorporation of biodiversity conservation issues in the land use planning process, and that the deficiencies in the land use planning process per se, as well as the lack of recognition in the political sphere (the domain of elected councilors), represent the core barriers to adopting the conservation priorities. I conclude that to effect behavior change towards adoption of conservation priorities the land use planning processes need to be supported and the political sphere need to be included in the behavior change process. 6 Chapter 4 therefore focuses on the new target group that emerged as essential in the previous chapter, locally elected councilors. I found that councilors do actually consider land use planning procedures as being important, but also as being dysfunctional. Councilors do value their natural environment for themselves as well as for its tourism value, but most councilors had little understanding of what the term “biodiversity” means and did not connect the term “sustainability” with the natural environment. It became also evident, that councilors do not see conservation in a predominantly positive manner. Chapter 5 therefore yields insight on councilor’s perception that environmental protection and development are mutually exclusive, and the negative frames attached to the conservation endeavor as being socially unjust, disrespectful and utopian. In Chapter 6 I investigated the usefulness of a tractable and well established measure of environmental attitudes or beliefs. I assessed my target audience’s responses to the New Ecological Paradigm scale and the Inclusion of Nature in Self scale. I conclude in Chapter 7 with an account of the difficulties I encountered during the project, an assessment of my project from a social marketing perspective, components of my project that did not yield the results expected, and a proposal for future research.
- Full Text:
- Date Issued: 2011
- Authors: Wilhelm-Rechmann, Angelika
- Date: 2011
- Subjects: Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10603 , http://hdl.handle.net/10948/1550 , Nature conservation -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Description: The study presented here describes an attempt to bridge the gap between systematic conservation assessment and decision-making for land-use planning in the Eastern Cape province, South Africa. The aim was to investigate how to effectively convince officials concerned with land use planning processes in the local municipal sphere to include conservation priorities meaningfully in their processes. The approach used to reach this aim was social marketing, the use of marketing technologies and concepts to effect behavior changes to further societal good. So far social marketing is not commonly used in the conservation domain; I therefore aimed also at proving the usefulness of this approach for conservation. Following the introduction which provides background to the project and a more detailed summary, Chapter 2 provides a detailed and comprehensive review of the considerations and concepts regarding the use of social marketing in a context geared at protecting nature. The research on the primary target group for this study, officials concerned with land use planning processes in the local municipal sphere is described in Chapter 3. The main outcomes were that land use planners perceive few needs with regards to implementing the incorporation of biodiversity conservation issues in the land use planning process, and that the deficiencies in the land use planning process per se, as well as the lack of recognition in the political sphere (the domain of elected councilors), represent the core barriers to adopting the conservation priorities. I conclude that to effect behavior change towards adoption of conservation priorities the land use planning processes need to be supported and the political sphere need to be included in the behavior change process. 6 Chapter 4 therefore focuses on the new target group that emerged as essential in the previous chapter, locally elected councilors. I found that councilors do actually consider land use planning procedures as being important, but also as being dysfunctional. Councilors do value their natural environment for themselves as well as for its tourism value, but most councilors had little understanding of what the term “biodiversity” means and did not connect the term “sustainability” with the natural environment. It became also evident, that councilors do not see conservation in a predominantly positive manner. Chapter 5 therefore yields insight on councilor’s perception that environmental protection and development are mutually exclusive, and the negative frames attached to the conservation endeavor as being socially unjust, disrespectful and utopian. In Chapter 6 I investigated the usefulness of a tractable and well established measure of environmental attitudes or beliefs. I assessed my target audience’s responses to the New Ecological Paradigm scale and the Inclusion of Nature in Self scale. I conclude in Chapter 7 with an account of the difficulties I encountered during the project, an assessment of my project from a social marketing perspective, components of my project that did not yield the results expected, and a proposal for future research.
- Full Text:
- Date Issued: 2011
Utilizing geocaching to reduce obesity and increase tourism
- Authors: Von Solms, Woudi
- Date: 2011
- Subjects: Sports and tourism , Obesity
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9291 , http://hdl.handle.net/10948/d1011157 , Sports and tourism , Obesity
- Description: Tourism has social and economic benefits. Economic benefits are received through tourists visiting tourist attractions. Social benefits related to benefits tourists receive personally when visiting tourist attractions. The number of individuals that are obese are constantly increasing and leads to hazardous medical conditions. The aim of this research study was to determine the extent to which geocaching can be used to increase tourism and decrease obesity. Geocaching is similar to a treasure hunt where participant use clues and a Global Positioning System device to find a treasure that are called a cache. The cache is filled with trinkets that are exchanged by participants that find the cache. Students of the second avenue campus of the Nelson Mandela Metropolitan University were used as respondents and given information on what geocaching involve. Three geocaches were hidden in The Boardwalk Casino and Entertainment World in Summerstrand, Port Elizabeth. The respondents met at The Boardwalk Casino and Entertainment World where a clue and map was provided. After finding the cache the respondents was asked to complete an anonymous questionnaire. The results were calculated and conclusions and recommendations were made. The primary research process was conducted over too short a period of time to conclude whether it can lead to a reduction in obesity. However geocaching experience by respondents did show that the process of geocaching involves physical exercise, which is needed for losing weight. Research also indicated that respondents would like to geocache with family and friends. Geocaching with family and friends involves support which secondary research have also proven is important to losing weight and decreasing obesity. Respondents indicated that they enjoyed geocaching and would like to geocache in their free time. The indication of enjoying geocaching, participating in geocaching during free time allows travelling for leisure purposes as to geocache travelling is necessary and the majority of geocaches is hidden at tourist attractions. The combination of travelling to tourist attractions, enjoying the experience and partaking in physical exercise with family and friends involve two of the three main aspects seen as helping to reduce obesity: enjoyable physical activity and support from family and friends. The conclusion is therefore that geocaching can be utilised to increase tourism and reduce obesity.
- Full Text:
- Date Issued: 2011
- Authors: Von Solms, Woudi
- Date: 2011
- Subjects: Sports and tourism , Obesity
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9291 , http://hdl.handle.net/10948/d1011157 , Sports and tourism , Obesity
- Description: Tourism has social and economic benefits. Economic benefits are received through tourists visiting tourist attractions. Social benefits related to benefits tourists receive personally when visiting tourist attractions. The number of individuals that are obese are constantly increasing and leads to hazardous medical conditions. The aim of this research study was to determine the extent to which geocaching can be used to increase tourism and decrease obesity. Geocaching is similar to a treasure hunt where participant use clues and a Global Positioning System device to find a treasure that are called a cache. The cache is filled with trinkets that are exchanged by participants that find the cache. Students of the second avenue campus of the Nelson Mandela Metropolitan University were used as respondents and given information on what geocaching involve. Three geocaches were hidden in The Boardwalk Casino and Entertainment World in Summerstrand, Port Elizabeth. The respondents met at The Boardwalk Casino and Entertainment World where a clue and map was provided. After finding the cache the respondents was asked to complete an anonymous questionnaire. The results were calculated and conclusions and recommendations were made. The primary research process was conducted over too short a period of time to conclude whether it can lead to a reduction in obesity. However geocaching experience by respondents did show that the process of geocaching involves physical exercise, which is needed for losing weight. Research also indicated that respondents would like to geocache with family and friends. Geocaching with family and friends involves support which secondary research have also proven is important to losing weight and decreasing obesity. Respondents indicated that they enjoyed geocaching and would like to geocache in their free time. The indication of enjoying geocaching, participating in geocaching during free time allows travelling for leisure purposes as to geocache travelling is necessary and the majority of geocaches is hidden at tourist attractions. The combination of travelling to tourist attractions, enjoying the experience and partaking in physical exercise with family and friends involve two of the three main aspects seen as helping to reduce obesity: enjoyable physical activity and support from family and friends. The conclusion is therefore that geocaching can be utilised to increase tourism and reduce obesity.
- Full Text:
- Date Issued: 2011
Variability of the peak height of the ionospheric F2 layer over South Africa
- Authors: Mbambo, Makhangela Casey
- Date: 2011
- Subjects: Ionosphere -- South Africa , Ionosphere -- Observations , Ionosphere -- Research , Double layers (Astrophysics)
- Language: English
- Type: Thesis , Masters , MSc (Physics)
- Identifier: vital:11594 , http://hdl.handle.net/10353/446 , Ionosphere -- South Africa , Ionosphere -- Observations , Ionosphere -- Research , Double layers (Astrophysics)
- Description: Abstract This thesis will present an investigation into the variability of the maximum height of the ionospheric F2 layer, hmF2, with hour, season and latitude over the South African region. The dependence of hmF2 on solar and magnetic activity is also investigated. Data from three South African stations, namely Madimbo (22.4 S, 26.5 E), Grahamstown (33.3 S, 26.5 E) and Louisvale (28.5 S, 21.2 E) were used in this study. Initial results indicate that hmF2 shows a larger variability around midnight than during daytime for all the seasons. Monthly median values for hmF2 were used in all cases to illustrate the variability, and the International Reference Ionosphere (IRI) model has been used to investigate hmF2 predictability over South Africa. This research represents the initial steps towards a predictive model for the hmF2 parameter, with the long term aim of developing a new global hmF2 predictive model for the IRI. It is believed that this work will contribute signi cantly towards this aim through the understanding of the hmF2 parameter over a region that has not previously been investigated.
- Full Text:
- Date Issued: 2011
- Authors: Mbambo, Makhangela Casey
- Date: 2011
- Subjects: Ionosphere -- South Africa , Ionosphere -- Observations , Ionosphere -- Research , Double layers (Astrophysics)
- Language: English
- Type: Thesis , Masters , MSc (Physics)
- Identifier: vital:11594 , http://hdl.handle.net/10353/446 , Ionosphere -- South Africa , Ionosphere -- Observations , Ionosphere -- Research , Double layers (Astrophysics)
- Description: Abstract This thesis will present an investigation into the variability of the maximum height of the ionospheric F2 layer, hmF2, with hour, season and latitude over the South African region. The dependence of hmF2 on solar and magnetic activity is also investigated. Data from three South African stations, namely Madimbo (22.4 S, 26.5 E), Grahamstown (33.3 S, 26.5 E) and Louisvale (28.5 S, 21.2 E) were used in this study. Initial results indicate that hmF2 shows a larger variability around midnight than during daytime for all the seasons. Monthly median values for hmF2 were used in all cases to illustrate the variability, and the International Reference Ionosphere (IRI) model has been used to investigate hmF2 predictability over South Africa. This research represents the initial steps towards a predictive model for the hmF2 parameter, with the long term aim of developing a new global hmF2 predictive model for the IRI. It is believed that this work will contribute signi cantly towards this aim through the understanding of the hmF2 parameter over a region that has not previously been investigated.
- Full Text:
- Date Issued: 2011
VC’s tapestry unveiling address
- Authors: Badat, Saleem
- Date: 2011
- Language: English
- Type: text
- Identifier: vital:7589 , http://hdl.handle.net/10962/d1006580
- Description: From introduction: This afternoon we publicly launch an exquisite tapestry commissioned from the Keiskamma Arts Project based in Hamburg on the coast. It is intended to express the social purposes that are the rationale for our existence; the geography and environment of Rhodes University; the economic, political, historical and social forces that have shaped it over 107 years and the complexity, antinomies, paradoxes and ambiguities of Rhodes’ history. It is also intended to express our origins, where we have come from the road we have travelled and where we are today; the continuities and discontinuities that characterise Rhodes; the inexcusable and shameful actions of our past in which we can take no pride, as well as the courageous actions, successes and achievements in which we can take pride, and that we can and must celebrate. The launch of the tapestry is an important moment in our continuing journey as Rhodes University of critical reflection, ‘critical appreciation of where we come from,’ and ‘dialogical and analytic engagement with where we are now’ and where we seek to be in future. I have indicated that the launch of the tapestry is a moment in our continuing journey – a journey of the remaking, renewal, modernisation, transformation and further development of Rhodes University.
- Full Text:
- Date Issued: 2011
- Authors: Badat, Saleem
- Date: 2011
- Language: English
- Type: text
- Identifier: vital:7589 , http://hdl.handle.net/10962/d1006580
- Description: From introduction: This afternoon we publicly launch an exquisite tapestry commissioned from the Keiskamma Arts Project based in Hamburg on the coast. It is intended to express the social purposes that are the rationale for our existence; the geography and environment of Rhodes University; the economic, political, historical and social forces that have shaped it over 107 years and the complexity, antinomies, paradoxes and ambiguities of Rhodes’ history. It is also intended to express our origins, where we have come from the road we have travelled and where we are today; the continuities and discontinuities that characterise Rhodes; the inexcusable and shameful actions of our past in which we can take no pride, as well as the courageous actions, successes and achievements in which we can take pride, and that we can and must celebrate. The launch of the tapestry is an important moment in our continuing journey as Rhodes University of critical reflection, ‘critical appreciation of where we come from,’ and ‘dialogical and analytic engagement with where we are now’ and where we seek to be in future. I have indicated that the launch of the tapestry is a moment in our continuing journey – a journey of the remaking, renewal, modernisation, transformation and further development of Rhodes University.
- Full Text:
- Date Issued: 2011
Vicarious libality for sexual harassment at work
- Authors: Muzuva, Arthurnatious
- Date: 2011
- Subjects: Sexual harassment -- Law and legislation -- South Africa , Sex discrimination in employment -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10233 , http://hdl.handle.net/10948/d1011386 , Sexual harassment -- Law and legislation -- South Africa , Sex discrimination in employment -- Law and legislation -- South Africa
- Description: Sexual harassment has been in existence for a long time in the workplace without any attempt to understand, define and effectively combat this rather undesirable and serious form of misconduct. Until fairly recently, the growing problem of sexual harassment and its damaging effect have been given much attention by legal authorities and society at large. The effect of sexual harassment is that it embarrasses or humiliates the victim. The victim may also suffer from trauma which, in turn, affects his/her performance at work. Numerous definitions have been provided on what constitutes sexual harassment. Sexual harassment takes place when a women‟s sexual role overshadows her work role in the eyes of the male, whether it be a supervisor, co-worker, client or customer. In other words, her gender receives more attention than her work. Sexual harassment is also seen as unwanted conduct of a sexual nature that violates the rights of an employee and constitutes a barrier to equity in the workplace.1 The Bill of Rights in the Constitution2 entrenches the rights of everyone. Worth mentioning are the “right to equality”, “the right to dignity”, “the right to privacy” and “the right to fair labour practices”. Furthermore, section 6(3) of the Employment Equity Act3 states that “harassment is a form of unfair discrimination” which is prohibited in terms of section 6(1) of the same Act. Section 60 of the Employment Equity Act deals with statutory vicarious liability where the employer is held liable for his acts and/or omission to take measures to against sexual harassment or a failure to put a grievance procedure in place. Where such an employer has done what is reasonably necessary to prevent and to address sexual harassment, he/she will escape liability for the misconduct of the employee. This section also provides for mechanisms that an employer may employ to minimise liability where harassment has taken place. In addition to statutory vicarious liability is the common law vicarious liability, where the employer is vicariously liable for the delict of the employee. This form of liability is also referred to as “no-fault liability”. The employer will be held liable where the following requirements for vicarious liability in common law are met: firstly, there must be an “employer-employee relationship”, secondly, a “delict must be committed” and thirdly, the “employee must have been acting in the scope or course of employment when the delict was committed”. Liability can also be directly imputed on the employer. In this instance, it has to be proven that “the employer committed an act or omission; the act or omission was unlawful; the act or omission was culpable, intentional or negligent, and a third party suffered harm; either patrimonial damage or injury to personality; and the act or omission caused that harm”.
- Full Text:
- Date Issued: 2011
- Authors: Muzuva, Arthurnatious
- Date: 2011
- Subjects: Sexual harassment -- Law and legislation -- South Africa , Sex discrimination in employment -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10233 , http://hdl.handle.net/10948/d1011386 , Sexual harassment -- Law and legislation -- South Africa , Sex discrimination in employment -- Law and legislation -- South Africa
- Description: Sexual harassment has been in existence for a long time in the workplace without any attempt to understand, define and effectively combat this rather undesirable and serious form of misconduct. Until fairly recently, the growing problem of sexual harassment and its damaging effect have been given much attention by legal authorities and society at large. The effect of sexual harassment is that it embarrasses or humiliates the victim. The victim may also suffer from trauma which, in turn, affects his/her performance at work. Numerous definitions have been provided on what constitutes sexual harassment. Sexual harassment takes place when a women‟s sexual role overshadows her work role in the eyes of the male, whether it be a supervisor, co-worker, client or customer. In other words, her gender receives more attention than her work. Sexual harassment is also seen as unwanted conduct of a sexual nature that violates the rights of an employee and constitutes a barrier to equity in the workplace.1 The Bill of Rights in the Constitution2 entrenches the rights of everyone. Worth mentioning are the “right to equality”, “the right to dignity”, “the right to privacy” and “the right to fair labour practices”. Furthermore, section 6(3) of the Employment Equity Act3 states that “harassment is a form of unfair discrimination” which is prohibited in terms of section 6(1) of the same Act. Section 60 of the Employment Equity Act deals with statutory vicarious liability where the employer is held liable for his acts and/or omission to take measures to against sexual harassment or a failure to put a grievance procedure in place. Where such an employer has done what is reasonably necessary to prevent and to address sexual harassment, he/she will escape liability for the misconduct of the employee. This section also provides for mechanisms that an employer may employ to minimise liability where harassment has taken place. In addition to statutory vicarious liability is the common law vicarious liability, where the employer is vicariously liable for the delict of the employee. This form of liability is also referred to as “no-fault liability”. The employer will be held liable where the following requirements for vicarious liability in common law are met: firstly, there must be an “employer-employee relationship”, secondly, a “delict must be committed” and thirdly, the “employee must have been acting in the scope or course of employment when the delict was committed”. Liability can also be directly imputed on the employer. In this instance, it has to be proven that “the employer committed an act or omission; the act or omission was unlawful; the act or omission was culpable, intentional or negligent, and a third party suffered harm; either patrimonial damage or injury to personality; and the act or omission caused that harm”.
- Full Text:
- Date Issued: 2011
Vice-Chancellor's welcoming address 2011
- Authors: Badat, Saleem
- Date: 2011
- Language: English
- Type: text
- Identifier: vital:7591 , http://hdl.handle.net/10962/d1006582
- Description: From introduction: The Purposes of a University. So permit me to spend a few minutes on the meaning of a university and the three purposes. Rhodes University exists to serve. The first purpose is to produce knowledge, so that we can advance understanding of our natural and social worlds and enrich our scientific and cultural heritage. This means that we ‘test the inherited knowledge of earlier generations’, we dismantle the mumbo jumbo that masquerades for knowledge, we ‘reinvigorate’ knowledge, and we share our findings with others. As a university, our second purpose is to disseminate knowledge and to develop your minds. Our goal is to ensure that you can think imaginatively, ‘effectively and critically’; that you ‘achieve depth in some field of knowledge’; that you can critique ideas and views and construct alternatives, and that you can communicate cogently, orally and in writing. Our final purpose as a university is to undertake community engagement, whether this is as part of academic courses or your voluntary participation in community projects organized by our Community Engagement Office.
- Full Text:
- Date Issued: 2011
- Authors: Badat, Saleem
- Date: 2011
- Language: English
- Type: text
- Identifier: vital:7591 , http://hdl.handle.net/10962/d1006582
- Description: From introduction: The Purposes of a University. So permit me to spend a few minutes on the meaning of a university and the three purposes. Rhodes University exists to serve. The first purpose is to produce knowledge, so that we can advance understanding of our natural and social worlds and enrich our scientific and cultural heritage. This means that we ‘test the inherited knowledge of earlier generations’, we dismantle the mumbo jumbo that masquerades for knowledge, we ‘reinvigorate’ knowledge, and we share our findings with others. As a university, our second purpose is to disseminate knowledge and to develop your minds. Our goal is to ensure that you can think imaginatively, ‘effectively and critically’; that you ‘achieve depth in some field of knowledge’; that you can critique ideas and views and construct alternatives, and that you can communicate cogently, orally and in writing. Our final purpose as a university is to undertake community engagement, whether this is as part of academic courses or your voluntary participation in community projects organized by our Community Engagement Office.
- Full Text:
- Date Issued: 2011
Violence, postcolonial fiction, and the limits of sympathy:
- Authors: Marais, Mike
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143993 , vital:38301 , DOI: 10.1353/sdn.2011.0034
- Description: In this article, I consider the implications for fiction of Slavo Zizek’s argument that the violence of individual subjects is informed by ‘symbolic violence’ (1-2), that is, the distortions concomitant on languages’s constitutive, rather than merely referential, relation to the world.
- Full Text:
- Date Issued: 2011
- Authors: Marais, Mike
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143993 , vital:38301 , DOI: 10.1353/sdn.2011.0034
- Description: In this article, I consider the implications for fiction of Slavo Zizek’s argument that the violence of individual subjects is informed by ‘symbolic violence’ (1-2), that is, the distortions concomitant on languages’s constitutive, rather than merely referential, relation to the world.
- Full Text:
- Date Issued: 2011
Vision-guided tracking of complex tree-dimensional seams for robotic gas metal arc welding
- Authors: Hamed, Maien
- Date: 2011
- Subjects: Robot vision , Robotics , Gas metal arc welding
- Language: English
- Type: Thesis , Masters , MEngineering (Mechatronics)
- Identifier: vital:9646 , http://hdl.handle.net/10948/1428 , Robot vision , Robotics , Gas metal arc welding
- Description: Automation of welding systems is often restricted by the requirements of spatial information of the seams to be welded. When this cannot be obtained from the design of the welded parts and maintained using accurate xturing, the use of a seam teaching or tracking system becomes necessary. Optical seam teaching and tracking systems have many advantages compared to systems implemented with other sensor families. Direct vision promises to be a viable strategy for implementing optical seam tracking, which has been mainly done with laser vision. The current work investigated direct vision as a strategy for optical seam teaching and tracking. A robotic vision system has been implemented, consisting of an articulated robot, a hand mounted camera and a control computer. A description of the calibration methods and the seam and feature detection and three-dimensional scene reconstruction is given. The results showed that direct vision is a suitable strategy for seam detection and learning. A discussion of generalizing the method used as an architecture for simultanious system calibration and measurement estimation is provided.
- Full Text:
- Date Issued: 2011
- Authors: Hamed, Maien
- Date: 2011
- Subjects: Robot vision , Robotics , Gas metal arc welding
- Language: English
- Type: Thesis , Masters , MEngineering (Mechatronics)
- Identifier: vital:9646 , http://hdl.handle.net/10948/1428 , Robot vision , Robotics , Gas metal arc welding
- Description: Automation of welding systems is often restricted by the requirements of spatial information of the seams to be welded. When this cannot be obtained from the design of the welded parts and maintained using accurate xturing, the use of a seam teaching or tracking system becomes necessary. Optical seam teaching and tracking systems have many advantages compared to systems implemented with other sensor families. Direct vision promises to be a viable strategy for implementing optical seam tracking, which has been mainly done with laser vision. The current work investigated direct vision as a strategy for optical seam teaching and tracking. A robotic vision system has been implemented, consisting of an articulated robot, a hand mounted camera and a control computer. A description of the calibration methods and the seam and feature detection and three-dimensional scene reconstruction is given. The results showed that direct vision is a suitable strategy for seam detection and learning. A discussion of generalizing the method used as an architecture for simultanious system calibration and measurement estimation is provided.
- Full Text:
- Date Issued: 2011
Vocabulary development in a grade 7 class using dictionary skills: an action research project
- Authors: Wells, Stephanie Alice
- Date: 2011
- Subjects: English language -- Study and teaching (Elementary) -- South Africa -- Eastern Cape Vocabulary -- Study and teaching (Elementary) -- South Africa -- Eastern Cape English language Dictionaries -- Polyglot -- Study and teaching (Elementary) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1822 , http://hdl.handle.net/10962/d1003708
- Description: As I was involved as a voluntary, part-time teacher in a local, semi-rural school in the Eastern Cape, South Africa, I became increasingly aware of the learners' lack of English literacy. I therefore decided to do a practical research on vocabulary development, focusing on dictionary skills. In this thesis I describe how I implemented a vocabulary development programme as an Action Research project. My research group was a grade 7 class of English First Additional Language learners who had minimal exposure to English at school and in their communities. The class was a mixture of Afrikaans and isiXhosa home language speakers and the medium of instruction was Afrikaans. The school served a low-income community and was poorly resourced. As dictionary skills is a requirement of the national curriculum, I used 10 time-tabled lessons over a 5 week period to introduce the learners to dictionaries. My data sources were a journal detailing my reflections on each lesson; a video-recording of the lessons; small group interviews after each lesson which were audio-recorded; tasksheets on the work covered in class and questionnaires asking the learners for written responses to the lessons. The class teacher who filmed the lessons was also asked for feedback during and after the programme. My goals were to assess my teaching approach in these circumstances and to what extent the outcomes were positive for the learners. As I had come from a background of English Home Language teaching in good, well-resourced schools I found I had to question many of my assumptions. Although I was an experienced, qualified and confident teacher, I was continually having to reassess my teaching methods which were being challenged by very different classroom conditions. The outcomes of the research show why I was not able to achieve what I had thought I could in the time given.
- Full Text:
- Date Issued: 2011
- Authors: Wells, Stephanie Alice
- Date: 2011
- Subjects: English language -- Study and teaching (Elementary) -- South Africa -- Eastern Cape Vocabulary -- Study and teaching (Elementary) -- South Africa -- Eastern Cape English language Dictionaries -- Polyglot -- Study and teaching (Elementary) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1822 , http://hdl.handle.net/10962/d1003708
- Description: As I was involved as a voluntary, part-time teacher in a local, semi-rural school in the Eastern Cape, South Africa, I became increasingly aware of the learners' lack of English literacy. I therefore decided to do a practical research on vocabulary development, focusing on dictionary skills. In this thesis I describe how I implemented a vocabulary development programme as an Action Research project. My research group was a grade 7 class of English First Additional Language learners who had minimal exposure to English at school and in their communities. The class was a mixture of Afrikaans and isiXhosa home language speakers and the medium of instruction was Afrikaans. The school served a low-income community and was poorly resourced. As dictionary skills is a requirement of the national curriculum, I used 10 time-tabled lessons over a 5 week period to introduce the learners to dictionaries. My data sources were a journal detailing my reflections on each lesson; a video-recording of the lessons; small group interviews after each lesson which were audio-recorded; tasksheets on the work covered in class and questionnaires asking the learners for written responses to the lessons. The class teacher who filmed the lessons was also asked for feedback during and after the programme. My goals were to assess my teaching approach in these circumstances and to what extent the outcomes were positive for the learners. As I had come from a background of English Home Language teaching in good, well-resourced schools I found I had to question many of my assumptions. Although I was an experienced, qualified and confident teacher, I was continually having to reassess my teaching methods which were being challenged by very different classroom conditions. The outcomes of the research show why I was not able to achieve what I had thought I could in the time given.
- Full Text:
- Date Issued: 2011