"Effulgent in the firmament" the politics of representation and the politics of reception in South Africa's 'poetry of commitment', 1968-1983
- Authors: Mde, Vukani
- Date: 2002
- Subjects: South African literature -- Black authors -- History and criticism , Politics and literature -- South Africa -- History -- 20th century , Literature and state -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10987 , http://hdl.handle.net/10948/288 , South African literature -- Black authors -- History and criticism , Politics and literature -- South Africa -- History -- 20th century , Literature and state -- South Africa
- Description: This dissertation re-examines an era in the production and reception of English language poetry in South Africa by black writers. Intellectually the 1970's was the Black Consciousness phase of South African history and very few aspects of life in the country were untouched by the intellectual movement led by Steve Biko and other young black student leaders. The aesthetic and literary output of the time, like all other facets of South African life, exhibited the influence and pressures brought to bear by Black Consciousness. Moreover, the Black Consciousness poets introduced the most vibrant and innovative phase for English language poetry produced in South Africa. It is my contention, however, that such vibrancy and innovation has consistently been compromised by unsympathetic, often hostile, and almost-always ill-informed criticism. The dissertation offers a critique of the academic and journalistic practice of criticism in South Africa. I argue that critical practice in South Africa has been engaged throughout the twentieth century in the discursive enforcement of ‘discipline’. In his Discipline and Punish (1977) the French post-structuralist philosopher Michel Foucault demonstrated how power is wielded against oppressed/suppressed groups through self regulated proscriptions, and argued that power is a discursive rather than a corporeal phenomenon. My dissertation follows Foucault in reading the critical reception of Black Consciousness poetry as the practice of disciplinary power. The dissertation also engages critically with the poetry of Oswald Mtshali, Mongane Serote and Sipho Sepamla, and argues that their work is the inscription of black subjectivity into the literary and cultural mainstream. It situates their work within wider 6 societal debates and definitions of ‘blackness’. In this regard use is made again of Michel Foucault’s insights and methodology of discourse analysis as shown in The Archaeology of Knowledge (1972). I argue that Oswald Mtshali’s work is a failed attempt at a dissection of apartheid and colonialism from a broadly Christian and humanist perspective. In my reading of Mongane Serote I explore the relationship between women’s bodies and the practice of representation. It is my contention that Serote is most concerned with claims of belonging, and this is shown through his extensive use of the trope of ‘Mother’. My discussion of the poetry of Sipho Sepamla focuses on language and (self- )representation, particularly the use of practices of naming in constructing subjectivity. My contention is that Sepamla ultimately abandons attempts at representation in favour of oppositional self-construction in language. In the concluding chapter I defend the thesis that the politics of discipline have prevented the broad critical establishment from gaining access to these discursive constructions of blackness in the committed poetry of South Africa.
- Full Text:
- Date Issued: 2002
- Authors: Mde, Vukani
- Date: 2002
- Subjects: South African literature -- Black authors -- History and criticism , Politics and literature -- South Africa -- History -- 20th century , Literature and state -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10987 , http://hdl.handle.net/10948/288 , South African literature -- Black authors -- History and criticism , Politics and literature -- South Africa -- History -- 20th century , Literature and state -- South Africa
- Description: This dissertation re-examines an era in the production and reception of English language poetry in South Africa by black writers. Intellectually the 1970's was the Black Consciousness phase of South African history and very few aspects of life in the country were untouched by the intellectual movement led by Steve Biko and other young black student leaders. The aesthetic and literary output of the time, like all other facets of South African life, exhibited the influence and pressures brought to bear by Black Consciousness. Moreover, the Black Consciousness poets introduced the most vibrant and innovative phase for English language poetry produced in South Africa. It is my contention, however, that such vibrancy and innovation has consistently been compromised by unsympathetic, often hostile, and almost-always ill-informed criticism. The dissertation offers a critique of the academic and journalistic practice of criticism in South Africa. I argue that critical practice in South Africa has been engaged throughout the twentieth century in the discursive enforcement of ‘discipline’. In his Discipline and Punish (1977) the French post-structuralist philosopher Michel Foucault demonstrated how power is wielded against oppressed/suppressed groups through self regulated proscriptions, and argued that power is a discursive rather than a corporeal phenomenon. My dissertation follows Foucault in reading the critical reception of Black Consciousness poetry as the practice of disciplinary power. The dissertation also engages critically with the poetry of Oswald Mtshali, Mongane Serote and Sipho Sepamla, and argues that their work is the inscription of black subjectivity into the literary and cultural mainstream. It situates their work within wider 6 societal debates and definitions of ‘blackness’. In this regard use is made again of Michel Foucault’s insights and methodology of discourse analysis as shown in The Archaeology of Knowledge (1972). I argue that Oswald Mtshali’s work is a failed attempt at a dissection of apartheid and colonialism from a broadly Christian and humanist perspective. In my reading of Mongane Serote I explore the relationship between women’s bodies and the practice of representation. It is my contention that Serote is most concerned with claims of belonging, and this is shown through his extensive use of the trope of ‘Mother’. My discussion of the poetry of Sipho Sepamla focuses on language and (self- )representation, particularly the use of practices of naming in constructing subjectivity. My contention is that Sepamla ultimately abandons attempts at representation in favour of oppositional self-construction in language. In the concluding chapter I defend the thesis that the politics of discipline have prevented the broad critical establishment from gaining access to these discursive constructions of blackness in the committed poetry of South Africa.
- Full Text:
- Date Issued: 2002
"Speak American"! or language, power and education in Dearborn, Michigan: a case study of Arabic heritage learners and their community
- Authors: Ayouby, Kenneth Kahtan
- Date: 2004
- Subjects: Arabic language -- Study and teaching (Higher) -- Michigan -- Dearborn , Education and language -- Michigan -- Dearborn
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:11015 , http://hdl.handle.net/10948/369 , Arabic language -- Study and teaching (Higher) -- Michigan -- Dearborn , Education and language -- Michigan -- Dearborn
- Description: This study examines the history and development of the “Arabic as a foreign language” (AFL) programme in Dearborn Public Schools (in Michigan, the United States) in its socio-cultural and political context. More specifically, this study examines the significance of Arabic to the Arab immigrant and ethnic community in Dearborn in particular, but with reference to meanings generated and associated to Arabic by non- Arabs in the same locale. Although this study addresses questions similar to research conducted on Arab Americans in light of anthropological and sociological theoretical constructs, it is, however, unique in examining education and Arabic pedagogy in Dearborn from an Arab American studies and an educational multi-cultural perspective, predicated on/and drawing from Edward Said’s critique of Orientalism, Paulo Freire’s ideas about education, and Henry Giroux’s concern with critical pedagogy. In the American mindscape, the "East" has been the theatre of the exotic, the setting of the Other from colonial times to the present. The Arab and Muslim East have been constructed to represent an opposite of American culture, values and life. Through the agency of conflation, Arab (and Muslim) Americans are accordingly lumped together with people from abroad, making for their status as permanent outsiders. Thus, if the American Self represents an ideal, the inhabitants of this oppositional world of Arabs and Islam (an Anti-world) represent an Anti-self. A source of fear and object of hate and prejudice, this Anti-self is the object of derision and anything connected with it (e.g. language, customs, religion, etc.) becomes suspect and is devalued by association. This document has two objectives: First, to present an historical account of this context, and, secondly, to shed light on how and why things that are associated with Arab Americans in Dearborn are devalued. This is achieved by addressing the developments of meanings (of actions and symbols) in their American context, and how they have shaped (and still shape) the local culture's depiction of and understanding of Arab (and Muslim) Americans. Therefore, Arab American issues of language, culture and societal interactions should be understood as constituting a stream of American life, which represent a dimension of the total American experience, past and present, that is best understood through the paradigm of American studies. Viewing this experience as a cultural whole rather than as a series of unrelated fragments (e.g. immigration waves and settlement patterns, religious and state affiliations, assimilation and preservation debates), Arab American culture and issues begin to shine through as an organic and holistic experience whose characteristics are shared with other groups, suggesting research on this community is equally generalisable to others. ii As an academic work, this document promotes an understanding of the Arab American experience from an interdisciplinary point of view through focusing on the phenomenon of language in the community with emphasis placed on the AFL experience at school. Therefore, it is a broadly-framed outlook that permits, in an introductory way, a view of the richness of the Arab American experience, particularly in Dearborn, Michigan, as part of the American experience. Data were collected using two surveys, one for AFL students at a high school, and another was administered to adults in the community—in Dearborn. In addition, an action-research-based effort, individual personal interviews and focus groups were conducted with stakeholders in the community: parents/community members, teachers/school personnel and students, utilising personal involvement in understanding and analysing the data. Also, the study referred to archival and documentary evidence available in the school system. Four hypotheses regarding importance/significance and utility of Arabic were offered and tested by means of qualitative, interpretive analysis. Findings included: (1) Arab Americans valued Arabic as an emblem of their community in Dearborn, suggesting its employment as an indicator of political empowerment. (2) Conversely, in the non-Arab community Arabic was observed as a mark of the Other, and an artefact of ethnic retrenchment and rejection of assimilation. (3) Interestingly, however, development of English language competence emerged as a major concern in the community, outweighing Arabic language preservation. (4) While, language maintenance efforts in the community were observed as minimal, especially at the organisational level, and support for such programmes was marginal to nil. (5) Additionally, Arabic, while not the object of a desire to master as a medium of communication, was observed to signify a special symbol of heritage for Arab American youth in the Dearborn community, who may have rejected their parents’ ideas about learning Arabic, but had developed their own. (6) What is more, Arab American youth were observed developing a viable hybridised identity, whose mainstay is being “Arabic”, despite the dominance of English and Euro-Anglo cultural norms. (7) At the institutional level, Arabic was observed devalued in the school setting due to its association with Arabs, Islam, Arab Americans, and immigration. (8) Moreover, relations between Arab Americans and non-Arab Americans in the school system seems to have been equally impacted by this process of devaluation, furthering the cause of stigmatisation, prejudice and racism.
- Full Text:
- Date Issued: 2004
- Authors: Ayouby, Kenneth Kahtan
- Date: 2004
- Subjects: Arabic language -- Study and teaching (Higher) -- Michigan -- Dearborn , Education and language -- Michigan -- Dearborn
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:11015 , http://hdl.handle.net/10948/369 , Arabic language -- Study and teaching (Higher) -- Michigan -- Dearborn , Education and language -- Michigan -- Dearborn
- Description: This study examines the history and development of the “Arabic as a foreign language” (AFL) programme in Dearborn Public Schools (in Michigan, the United States) in its socio-cultural and political context. More specifically, this study examines the significance of Arabic to the Arab immigrant and ethnic community in Dearborn in particular, but with reference to meanings generated and associated to Arabic by non- Arabs in the same locale. Although this study addresses questions similar to research conducted on Arab Americans in light of anthropological and sociological theoretical constructs, it is, however, unique in examining education and Arabic pedagogy in Dearborn from an Arab American studies and an educational multi-cultural perspective, predicated on/and drawing from Edward Said’s critique of Orientalism, Paulo Freire’s ideas about education, and Henry Giroux’s concern with critical pedagogy. In the American mindscape, the "East" has been the theatre of the exotic, the setting of the Other from colonial times to the present. The Arab and Muslim East have been constructed to represent an opposite of American culture, values and life. Through the agency of conflation, Arab (and Muslim) Americans are accordingly lumped together with people from abroad, making for their status as permanent outsiders. Thus, if the American Self represents an ideal, the inhabitants of this oppositional world of Arabs and Islam (an Anti-world) represent an Anti-self. A source of fear and object of hate and prejudice, this Anti-self is the object of derision and anything connected with it (e.g. language, customs, religion, etc.) becomes suspect and is devalued by association. This document has two objectives: First, to present an historical account of this context, and, secondly, to shed light on how and why things that are associated with Arab Americans in Dearborn are devalued. This is achieved by addressing the developments of meanings (of actions and symbols) in their American context, and how they have shaped (and still shape) the local culture's depiction of and understanding of Arab (and Muslim) Americans. Therefore, Arab American issues of language, culture and societal interactions should be understood as constituting a stream of American life, which represent a dimension of the total American experience, past and present, that is best understood through the paradigm of American studies. Viewing this experience as a cultural whole rather than as a series of unrelated fragments (e.g. immigration waves and settlement patterns, religious and state affiliations, assimilation and preservation debates), Arab American culture and issues begin to shine through as an organic and holistic experience whose characteristics are shared with other groups, suggesting research on this community is equally generalisable to others. ii As an academic work, this document promotes an understanding of the Arab American experience from an interdisciplinary point of view through focusing on the phenomenon of language in the community with emphasis placed on the AFL experience at school. Therefore, it is a broadly-framed outlook that permits, in an introductory way, a view of the richness of the Arab American experience, particularly in Dearborn, Michigan, as part of the American experience. Data were collected using two surveys, one for AFL students at a high school, and another was administered to adults in the community—in Dearborn. In addition, an action-research-based effort, individual personal interviews and focus groups were conducted with stakeholders in the community: parents/community members, teachers/school personnel and students, utilising personal involvement in understanding and analysing the data. Also, the study referred to archival and documentary evidence available in the school system. Four hypotheses regarding importance/significance and utility of Arabic were offered and tested by means of qualitative, interpretive analysis. Findings included: (1) Arab Americans valued Arabic as an emblem of their community in Dearborn, suggesting its employment as an indicator of political empowerment. (2) Conversely, in the non-Arab community Arabic was observed as a mark of the Other, and an artefact of ethnic retrenchment and rejection of assimilation. (3) Interestingly, however, development of English language competence emerged as a major concern in the community, outweighing Arabic language preservation. (4) While, language maintenance efforts in the community were observed as minimal, especially at the organisational level, and support for such programmes was marginal to nil. (5) Additionally, Arabic, while not the object of a desire to master as a medium of communication, was observed to signify a special symbol of heritage for Arab American youth in the Dearborn community, who may have rejected their parents’ ideas about learning Arabic, but had developed their own. (6) What is more, Arab American youth were observed developing a viable hybridised identity, whose mainstay is being “Arabic”, despite the dominance of English and Euro-Anglo cultural norms. (7) At the institutional level, Arabic was observed devalued in the school setting due to its association with Arabs, Islam, Arab Americans, and immigration. (8) Moreover, relations between Arab Americans and non-Arab Americans in the school system seems to have been equally impacted by this process of devaluation, furthering the cause of stigmatisation, prejudice and racism.
- Full Text:
- Date Issued: 2004
A comparative normative survey of the isokinetic neck strength of senior elite South African rugby players and schoolboy rugby forwards
- Authors: Olivier, Pierre Emile
- Date: 2003
- Subjects: Rugby football -- South Africa -- Physiological aspects , Neck -- Muscles , Muscle strength , Rugby football players -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11026 , http://hdl.handle.net/10948/308 , Rugby football -- South Africa -- Physiological aspects , Neck -- Muscles , Muscle strength , Rugby football players -- South Africa
- Description: The aim of this study was to generate useful isokinetic normative data for various cervical musculature strength, range of motion and ratio variables based on different positional categories in a sample of senior elite South African rugby players. Normative data was generated for the following variables: peak torque, power generated at 0.2 of a second, active and passive range of motion, the ratio of peak torque flexion to peak torque extension (PTF/PTE), the ratio of peak torque lateral flexion left to peak torque lateral flexion right (PTL/PTR), the ratios of peak torque to body weight (PT/BW) and the ratios of peak torque to lean body mass (PT/LBM). Furthermore, the data gathered from the senior elite players was compared to similar data obtained from a sample of schoolboy rugby forwards to detect statistically significant differences (p < .05). A normative survey design was used in which 189 subjects from eight provincial unions participated in a one off evaluation session. The evaluation session comprised of various anthropometrical measurements and an isokinetic cervical musculature assessment. The normative data, displayed in Stanine tables, was generated for four positional categories: the front row (# 1-3), the second row (# 4-5), the back row (# 6-8) and the backline (# 9 -15). The second row positional category performed the best on the peak flexion torque variable (44.04 Nm). The front row positional category achieved the largest average peak extension torque (65.6 Nm). The second row positional category achieved the largest average peak lateral flexion right torque (69.42 Nm). A similar result was observed with the measurement of peak lateral flexion left torque, with the second row positional category achieving the largest average peak lateral flexion left torque (66.31 Nm). The backline positional category achieved the lowest averages on all the abovementioned peak torque variables. The front row positional category performed the best on the flexion power generated at 0.2 of a second variable (160.92 W). The front row positional category again achieved the largest extension power generated at 0.2 of a second average (237.02 W). The second row positional category achieved the largest lateral flexion right power generated at 0.2 of a second average (269.81 W). Similar results were observed with the measurement of lateral flexion left power generated at 0.2 of a second. The second row positional category achieved the largest lateral flexion left power generated at 0.2 of a second average (259.62 W). Again the backline players achieved the smallest power generated at 0.2 of a second averages for all the above-mentioned power variables. The measurement of passive (PROMFE) and active (AROMFE) range of motion for flexion to extension revealed that the second row had the largest average PROMFE (125.44°). The measurement of AROMFE revealed a similar result. The second row again had the largest average AROMFE (108.45°). The measurement of passive (PROMLF) and active (PROMFE) range of motion for lateral flexion left to right revealed smaller and different results to those found for PROMFE and AROMFE. For the variable of PROMLF the backline players had the largest average PROMLF (119.44°). Conversely, the second row had the largest average AROMLF (106.96°). The calculation of the various ratios revealed great variation between the positional categories. This can be attributed to the functional requirements the players have to adhere to, to be successful in their position. Various other statistical calculations were performed to draw the average force distance graphs for the positional categories for the peak torque variables. Furthermore the force distance graphs were assessed to determine the players’ ability to maintain 80% of peak torque. All the senior elite positional categories proved to be significantly (p < .05) older and heavier than the schoolboy forwards. The senior elite forward positional categories were also significantly (p < .05) taller than the schoolboy forward. There however proved to be no significant difference (p > .05) in stature between the backline and schoolboy forwards. All the positional categories proved to have significantly thicker (p < .05) necks, but significantly shorter (p < .05) cervical spines than the schoolboy forwards. The forward positional categories demonstrated to be significantly stronger (p < .05), on all peak torque measures, than the schoolboy forwards. The same was observed between the backline and schoolboy forwards, however no statistically significant difference (p > .05) was observed between the respective sample groups for the measure of peak lateral flexion left torque. For all the measures of power generated at 0.2 of a second, the senior forward positional categories proved to be significantly more powerful (p < .05) than the schoolboy forwards. The senior backline, although significantly more powerful (p < .05) in the flexion movement pattern, proved to be significantly less powerful (p < .05) than the schoolboy forwards in the lateral flexion right movement pattern. No statistically significant differences (p < .05) were found to exist between the senior backline and schoolboy forwards for the extension and lateral flexion left power generated at 0.2 of a second variables. All positional categories proved to have significantly smaller (p < .05) active and passive ranges of motion compared to the schoolboy forwards. Conversely, the senior elite players had significantly larger (p < .05) ratios (PTF/PTE, PTL/PTR, PT/BW and PT/LBM) than the schoolboy forwards. Literature has identified schoolboy rugby as having a much higher incidence of cervical spinal injuries than senior rugby. It can thus be inferred from the above information that the variables of peak torque and power generated at 0.2 of a second play a important role in safeguarding a player from injury on the field of play. Furthermore, calculated ratios show that senior players, especially the forwards, have undergone adaptive changes in cervical musculature strength to meet the requirements of the position they play in, thereby safeguarding themselves from cervical spinal injury. Proper cervical musculature conditioning has been cited in the literature as being an effective but neglected method of preventing cervical spinal injuries. The generation of normative data, concerning cervical musculature performance, can thus be used to prevent the occurrence of cervical injuries and re-injury of the cervical spine by providing a standard of musculature strength for safe participation in rugby, and possibly other collision type sports, and a quantified guide for successful patient rehabilitation respectively.
- Full Text:
- Date Issued: 2003
- Authors: Olivier, Pierre Emile
- Date: 2003
- Subjects: Rugby football -- South Africa -- Physiological aspects , Neck -- Muscles , Muscle strength , Rugby football players -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11026 , http://hdl.handle.net/10948/308 , Rugby football -- South Africa -- Physiological aspects , Neck -- Muscles , Muscle strength , Rugby football players -- South Africa
- Description: The aim of this study was to generate useful isokinetic normative data for various cervical musculature strength, range of motion and ratio variables based on different positional categories in a sample of senior elite South African rugby players. Normative data was generated for the following variables: peak torque, power generated at 0.2 of a second, active and passive range of motion, the ratio of peak torque flexion to peak torque extension (PTF/PTE), the ratio of peak torque lateral flexion left to peak torque lateral flexion right (PTL/PTR), the ratios of peak torque to body weight (PT/BW) and the ratios of peak torque to lean body mass (PT/LBM). Furthermore, the data gathered from the senior elite players was compared to similar data obtained from a sample of schoolboy rugby forwards to detect statistically significant differences (p < .05). A normative survey design was used in which 189 subjects from eight provincial unions participated in a one off evaluation session. The evaluation session comprised of various anthropometrical measurements and an isokinetic cervical musculature assessment. The normative data, displayed in Stanine tables, was generated for four positional categories: the front row (# 1-3), the second row (# 4-5), the back row (# 6-8) and the backline (# 9 -15). The second row positional category performed the best on the peak flexion torque variable (44.04 Nm). The front row positional category achieved the largest average peak extension torque (65.6 Nm). The second row positional category achieved the largest average peak lateral flexion right torque (69.42 Nm). A similar result was observed with the measurement of peak lateral flexion left torque, with the second row positional category achieving the largest average peak lateral flexion left torque (66.31 Nm). The backline positional category achieved the lowest averages on all the abovementioned peak torque variables. The front row positional category performed the best on the flexion power generated at 0.2 of a second variable (160.92 W). The front row positional category again achieved the largest extension power generated at 0.2 of a second average (237.02 W). The second row positional category achieved the largest lateral flexion right power generated at 0.2 of a second average (269.81 W). Similar results were observed with the measurement of lateral flexion left power generated at 0.2 of a second. The second row positional category achieved the largest lateral flexion left power generated at 0.2 of a second average (259.62 W). Again the backline players achieved the smallest power generated at 0.2 of a second averages for all the above-mentioned power variables. The measurement of passive (PROMFE) and active (AROMFE) range of motion for flexion to extension revealed that the second row had the largest average PROMFE (125.44°). The measurement of AROMFE revealed a similar result. The second row again had the largest average AROMFE (108.45°). The measurement of passive (PROMLF) and active (PROMFE) range of motion for lateral flexion left to right revealed smaller and different results to those found for PROMFE and AROMFE. For the variable of PROMLF the backline players had the largest average PROMLF (119.44°). Conversely, the second row had the largest average AROMLF (106.96°). The calculation of the various ratios revealed great variation between the positional categories. This can be attributed to the functional requirements the players have to adhere to, to be successful in their position. Various other statistical calculations were performed to draw the average force distance graphs for the positional categories for the peak torque variables. Furthermore the force distance graphs were assessed to determine the players’ ability to maintain 80% of peak torque. All the senior elite positional categories proved to be significantly (p < .05) older and heavier than the schoolboy forwards. The senior elite forward positional categories were also significantly (p < .05) taller than the schoolboy forward. There however proved to be no significant difference (p > .05) in stature between the backline and schoolboy forwards. All the positional categories proved to have significantly thicker (p < .05) necks, but significantly shorter (p < .05) cervical spines than the schoolboy forwards. The forward positional categories demonstrated to be significantly stronger (p < .05), on all peak torque measures, than the schoolboy forwards. The same was observed between the backline and schoolboy forwards, however no statistically significant difference (p > .05) was observed between the respective sample groups for the measure of peak lateral flexion left torque. For all the measures of power generated at 0.2 of a second, the senior forward positional categories proved to be significantly more powerful (p < .05) than the schoolboy forwards. The senior backline, although significantly more powerful (p < .05) in the flexion movement pattern, proved to be significantly less powerful (p < .05) than the schoolboy forwards in the lateral flexion right movement pattern. No statistically significant differences (p < .05) were found to exist between the senior backline and schoolboy forwards for the extension and lateral flexion left power generated at 0.2 of a second variables. All positional categories proved to have significantly smaller (p < .05) active and passive ranges of motion compared to the schoolboy forwards. Conversely, the senior elite players had significantly larger (p < .05) ratios (PTF/PTE, PTL/PTR, PT/BW and PT/LBM) than the schoolboy forwards. Literature has identified schoolboy rugby as having a much higher incidence of cervical spinal injuries than senior rugby. It can thus be inferred from the above information that the variables of peak torque and power generated at 0.2 of a second play a important role in safeguarding a player from injury on the field of play. Furthermore, calculated ratios show that senior players, especially the forwards, have undergone adaptive changes in cervical musculature strength to meet the requirements of the position they play in, thereby safeguarding themselves from cervical spinal injury. Proper cervical musculature conditioning has been cited in the literature as being an effective but neglected method of preventing cervical spinal injuries. The generation of normative data, concerning cervical musculature performance, can thus be used to prevent the occurrence of cervical injuries and re-injury of the cervical spine by providing a standard of musculature strength for safe participation in rugby, and possibly other collision type sports, and a quantified guide for successful patient rehabilitation respectively.
- Full Text:
- Date Issued: 2003
A comparative study of employment discrimination in South Africa and Canada
- Authors: Dlamini, David Vusi
- Date: 2004
- Subjects: Discrimination in employment -- Law and Legislation -- South Africa , Discrimination in employment -- Law and legislation -- Canada
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11039 , http://hdl.handle.net/10948/330 , Discrimination in employment -- Law and Legislation -- South Africa , Discrimination in employment -- Law and legislation -- Canada
- Description: South Africa and Canada have emerged from a history fraught of inequalities, which were characterised by segregationist practices. Such inequalities have served as an epitome of discrimination taking place in the society and the workplace in both countries. Both South Africa and Canada had their discrimination affecting black peoples (Africans, Indians and Coloureds) and Aboriginal peoples (Indians, Inuits or Métis) respectively, women and people with disabilities. In both countries discrimination has polarised society. It is against this backdrop that both countries have attempted to eliminate unfair discrimination through the promulgation of relevant legislation that seeks to, inter alia, provide the regulatory framework in respect of employment discrimination. With the foregoing in mind, the purpose of this work is the provision of a selection of comparable aspects of employment discrimination in Canada and South Africa. This selection comprises discrimination on the basis of race, gender, sex, pregnancy, age and HIV/AIDS. The study uses, as its departure point, both countries’ constitutional framework to elicit the extent to which protection against unfair discrimination is extended to the workforce. Apart from looking at the constitutional provisions towards the elimination of unfair discrimination, reference is made to specific employment statutory provisions in order to provide a comprehensive and explicit picture of how workplace discrimination in both countries is regulated. The study focuses on substantive law from both countries about the above -mentioned aspects of discrimination. This is informed by the very nature and scope of the study because any concentration on procedural and evidentiary aspects of discrimination could lead to failure to achieve the objectives of the study. It also looks at specific Canadian and South African case law, judgments of the courts and jurisprudence in the field of employment discrimination in order that the reader is presented with a clearer picture of recent developments in addressing workplace inequalities.
- Full Text:
- Date Issued: 2004
- Authors: Dlamini, David Vusi
- Date: 2004
- Subjects: Discrimination in employment -- Law and Legislation -- South Africa , Discrimination in employment -- Law and legislation -- Canada
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11039 , http://hdl.handle.net/10948/330 , Discrimination in employment -- Law and Legislation -- South Africa , Discrimination in employment -- Law and legislation -- Canada
- Description: South Africa and Canada have emerged from a history fraught of inequalities, which were characterised by segregationist practices. Such inequalities have served as an epitome of discrimination taking place in the society and the workplace in both countries. Both South Africa and Canada had their discrimination affecting black peoples (Africans, Indians and Coloureds) and Aboriginal peoples (Indians, Inuits or Métis) respectively, women and people with disabilities. In both countries discrimination has polarised society. It is against this backdrop that both countries have attempted to eliminate unfair discrimination through the promulgation of relevant legislation that seeks to, inter alia, provide the regulatory framework in respect of employment discrimination. With the foregoing in mind, the purpose of this work is the provision of a selection of comparable aspects of employment discrimination in Canada and South Africa. This selection comprises discrimination on the basis of race, gender, sex, pregnancy, age and HIV/AIDS. The study uses, as its departure point, both countries’ constitutional framework to elicit the extent to which protection against unfair discrimination is extended to the workforce. Apart from looking at the constitutional provisions towards the elimination of unfair discrimination, reference is made to specific employment statutory provisions in order to provide a comprehensive and explicit picture of how workplace discrimination in both countries is regulated. The study focuses on substantive law from both countries about the above -mentioned aspects of discrimination. This is informed by the very nature and scope of the study because any concentration on procedural and evidentiary aspects of discrimination could lead to failure to achieve the objectives of the study. It also looks at specific Canadian and South African case law, judgments of the courts and jurisprudence in the field of employment discrimination in order that the reader is presented with a clearer picture of recent developments in addressing workplace inequalities.
- Full Text:
- Date Issued: 2004
A comparison of programming notations for a tertiary level introductory programming course
- Authors: Cilliers, Charmain Barbara
- Date: 2004
- Subjects: Computer programming -- Study and teaching (Higher) -- South Africa , Computer programmers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11093 , http://hdl.handle.net/10948/d1019679
- Description: Increasing pressure from national government to improve throughput at South African tertiary education institutions presents challenges to educators of introductory programming courses. In response, educators must adopt effective methods and strategies that encourage novice programmers to be successful in such courses. An approach that seeks to increase and maintain satisfactory throughput is the modification of the teaching model in these courses by adjusting presentation techniques. This thesis investigates the effect of integrating an experimental iconic programming notation and associated development environment with existing conventional textual technological support in the teaching model of a tertiary level introductory programming course. The investigation compares the performance achievement of novice programmers using only conventional textual technological support with that of novice programmers using the integrated iconic and conventional textual technological support. In preparation for the investigation, interpretation of existing knowledge on the behaviour of novice programmers while learning to program results in a novel framework of eight novice programmer requirements for technological support in an introductory programming course. This framework is applied in the examination of existing categories of technological support as well as in the design of new technological support for novice programmers learning to program. It thus provides information for the selection of existing and the design of new introductory programming technological support. The findings of the investigation suggest strong evidence that performance achievement of novice programmers in a tertiary level introductory programming course improves significantly with the inclusion of iconic technological support in the teaching model. The benefits are particularly evident in the portion of the novice programmer population who have been identified as being at risk of being successful in the course. Novice programmers identified as being at risk perform substantially better when using iconic technological support concurrently with conventional textual technological support than their equals who use only the latter form. Considerably more at risk novice programmers using the integrated form of technological support are in fact successful in the introductory programming course when compared with their counterparts who use conventional textual technological support only. The contributions of this thesis address deficiencies existing in current documented research. These contributions are primarily apparent in a number of distinct areas, namely: • formalisation of a novel framework of novice programmer requirements for technological support in an introductory programming course; • application of the framework as a formal evaluation technique; • application of the framework in the design of a visual iconic programming notation and development environment; • enhancement of existing empirical evidence and experimental research methodology typically applied to studies in programming; as well as • a proposal for a modified introductory programming course teaching model. The thesis has effectively applied substantial existing research on the cognitive model of the novice programmer as well as that on experimental technological support. The increase of throughput to a recommended rate of 75 percent in the tertiary level introductory programming course at the University of Port Elizabeth is attributed solely to the incorporation of iconic technological support in the teaching model of the course.
- Full Text:
- Date Issued: 2004
- Authors: Cilliers, Charmain Barbara
- Date: 2004
- Subjects: Computer programming -- Study and teaching (Higher) -- South Africa , Computer programmers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11093 , http://hdl.handle.net/10948/d1019679
- Description: Increasing pressure from national government to improve throughput at South African tertiary education institutions presents challenges to educators of introductory programming courses. In response, educators must adopt effective methods and strategies that encourage novice programmers to be successful in such courses. An approach that seeks to increase and maintain satisfactory throughput is the modification of the teaching model in these courses by adjusting presentation techniques. This thesis investigates the effect of integrating an experimental iconic programming notation and associated development environment with existing conventional textual technological support in the teaching model of a tertiary level introductory programming course. The investigation compares the performance achievement of novice programmers using only conventional textual technological support with that of novice programmers using the integrated iconic and conventional textual technological support. In preparation for the investigation, interpretation of existing knowledge on the behaviour of novice programmers while learning to program results in a novel framework of eight novice programmer requirements for technological support in an introductory programming course. This framework is applied in the examination of existing categories of technological support as well as in the design of new technological support for novice programmers learning to program. It thus provides information for the selection of existing and the design of new introductory programming technological support. The findings of the investigation suggest strong evidence that performance achievement of novice programmers in a tertiary level introductory programming course improves significantly with the inclusion of iconic technological support in the teaching model. The benefits are particularly evident in the portion of the novice programmer population who have been identified as being at risk of being successful in the course. Novice programmers identified as being at risk perform substantially better when using iconic technological support concurrently with conventional textual technological support than their equals who use only the latter form. Considerably more at risk novice programmers using the integrated form of technological support are in fact successful in the introductory programming course when compared with their counterparts who use conventional textual technological support only. The contributions of this thesis address deficiencies existing in current documented research. These contributions are primarily apparent in a number of distinct areas, namely: • formalisation of a novel framework of novice programmer requirements for technological support in an introductory programming course; • application of the framework as a formal evaluation technique; • application of the framework in the design of a visual iconic programming notation and development environment; • enhancement of existing empirical evidence and experimental research methodology typically applied to studies in programming; as well as • a proposal for a modified introductory programming course teaching model. The thesis has effectively applied substantial existing research on the cognitive model of the novice programmer as well as that on experimental technological support. The increase of throughput to a recommended rate of 75 percent in the tertiary level introductory programming course at the University of Port Elizabeth is attributed solely to the incorporation of iconic technological support in the teaching model of the course.
- Full Text:
- Date Issued: 2004
A critical analysis of the influence of the "Prevention of the illegal eviction from and unlawful occupation of Land Act 19 of 1998" on investment in residential income-producing property
- Authors: Botha, Brink
- Date: 2004
- Subjects: Rental housing -- Law and legislation -- South Africa , Eviction -- Law and legislation -- South Africa , Occupancy (Law) -- South Africa , Real estate investment -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11005 , http://hdl.handle.net/10948/321 , Rental housing -- Law and legislation -- South Africa , Eviction -- Law and legislation -- South Africa , Occupancy (Law) -- South Africa , Real estate investment -- Law and legislation -- South Africa
- Description: This research will focus on the influence of legislation (as indicated in this research) on the investment decision in residential income-producing property. Assumptions, as recorded in the hypothesis of this study, indicate that the legislation had a changing influence on the investment decision in residential income-producing property in comparison to the time period prior to the promulgation of the legislation. The research methodology will be based on a comparative analysis of the current legislation and the proposed Draft Amendment Bill. This analysis will be tested by means of a case study analysis incorporating a phenomenological study based on written data. The problems, sub-problems and hypothesis will be addressed and tested in this research in conjunction with the prescribed research methodology. This research is concluded by means of a synopsis and recommendations.
- Full Text:
- Date Issued: 2004
- Authors: Botha, Brink
- Date: 2004
- Subjects: Rental housing -- Law and legislation -- South Africa , Eviction -- Law and legislation -- South Africa , Occupancy (Law) -- South Africa , Real estate investment -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11005 , http://hdl.handle.net/10948/321 , Rental housing -- Law and legislation -- South Africa , Eviction -- Law and legislation -- South Africa , Occupancy (Law) -- South Africa , Real estate investment -- Law and legislation -- South Africa
- Description: This research will focus on the influence of legislation (as indicated in this research) on the investment decision in residential income-producing property. Assumptions, as recorded in the hypothesis of this study, indicate that the legislation had a changing influence on the investment decision in residential income-producing property in comparison to the time period prior to the promulgation of the legislation. The research methodology will be based on a comparative analysis of the current legislation and the proposed Draft Amendment Bill. This analysis will be tested by means of a case study analysis incorporating a phenomenological study based on written data. The problems, sub-problems and hypothesis will be addressed and tested in this research in conjunction with the prescribed research methodology. This research is concluded by means of a synopsis and recommendations.
- Full Text:
- Date Issued: 2004
A logos of difference: the Kantian roots of Derrida's deconstructive thinking
- Authors: Hurst, Andrea Margaret
- Date: 1999
- Subjects: Derrida, Jacques -- Philosophy , Deconstruction , Philosophy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11003 , http://hdl.handle.net/10948/d1015554
- Description: This study concerns a contemporary articulation of the age-old limit/possibility (truth/scepticism) contest in Western metaphysics. Traditional `either/or' logic advises that scepticism is a necessary consequence of the assailability of truth; hence the concerted effort in the history of philosophy to preserve the possibility of truth against any flicker of uncertainty. Here, it is argued that contemporary thinking sees the possibility of `absolute' truth lose its ground. However, a concomitant shift to a `logos of difference' averts the consequence of scepticism. Thus, the justification for this study could be articulated in terms of the imperative, if a cardinal moment in contemporary thought is to be sustained, to understand this shift in logos, work through its implications and learn to live with its effects. In this respect, an attempt is made throughout to situate and interpret Derrida's `deconstructive thinking' as exemplar. Derrida's thinking finds roots (not without signs of insurrection) in Kant's `Copernican revolution,' construed as the first shift towards the contemporary logos in question. Here, Kant refuted the postulate of an independent `world' by demonstrating that `reality' was the result of a cognitive order imposed on what `exists' by the rational subject. Knowledge, therefore, depended not on matching statements with pre-existing `things,' but on knowing the `rules' that determined how an object had to be if it was to be known at all. Kant maintained that certain, objective knowledge was possible, due to the completeness and universality of the forms of intuition and the categories of the understanding. Kant's `Copernican revolution' provided the opening for a second shift inaugurated by the so- called `linguistic turn.' Here, thinkers contested what Kant took for granted; namely that `constitutive interpretations' (cognitions/concepts) formed a `reality' independently of language. The basic premise underpinning the `linguistic turn,' therefore, is that language (signification) and `reality' are inseparable. Henceforth, the possibility of final, enduring `constitutive interpretations' whose `truth,' in principle, is discoverable, depends on whether or not the language which mediates human rationality can form a complete and universal system. This question resurrects the very limit/possibility debate (in the form of a structuralism/postmodernism stand-off) that Kant thought he had resolved in mediating between rationalist and empiricist extremes. In contemporary terms, philosophers who, bound by either/or logic, wish to avoid the sceptical trap of `anything goes' postmodernism, must assume that language (signification) can form a complete and universal system. However, in his deconstructive readings of Husserl, Saussure and `structuralism,' Derrida demonstrates the untenability of this assumption. At the same time, he shows that the sceptical `alternative' may be avoided by recognising the limitations of `either/or' logic. Again, Derrida's thinking may be traced to Kant's; this time to his analysis of the `first antinomy.' In accordance with Kant's analysis here of what is ultimately the logic of `complex systems' (Cilliers), Derrida offers a `logos of difference,' which skirts the strictures of structuralism while avoiding the trap of postmodern scepticism by accommodating both moments of limit and possibility in an indissoluble interplay.
- Full Text:
- Date Issued: 1999
- Authors: Hurst, Andrea Margaret
- Date: 1999
- Subjects: Derrida, Jacques -- Philosophy , Deconstruction , Philosophy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11003 , http://hdl.handle.net/10948/d1015554
- Description: This study concerns a contemporary articulation of the age-old limit/possibility (truth/scepticism) contest in Western metaphysics. Traditional `either/or' logic advises that scepticism is a necessary consequence of the assailability of truth; hence the concerted effort in the history of philosophy to preserve the possibility of truth against any flicker of uncertainty. Here, it is argued that contemporary thinking sees the possibility of `absolute' truth lose its ground. However, a concomitant shift to a `logos of difference' averts the consequence of scepticism. Thus, the justification for this study could be articulated in terms of the imperative, if a cardinal moment in contemporary thought is to be sustained, to understand this shift in logos, work through its implications and learn to live with its effects. In this respect, an attempt is made throughout to situate and interpret Derrida's `deconstructive thinking' as exemplar. Derrida's thinking finds roots (not without signs of insurrection) in Kant's `Copernican revolution,' construed as the first shift towards the contemporary logos in question. Here, Kant refuted the postulate of an independent `world' by demonstrating that `reality' was the result of a cognitive order imposed on what `exists' by the rational subject. Knowledge, therefore, depended not on matching statements with pre-existing `things,' but on knowing the `rules' that determined how an object had to be if it was to be known at all. Kant maintained that certain, objective knowledge was possible, due to the completeness and universality of the forms of intuition and the categories of the understanding. Kant's `Copernican revolution' provided the opening for a second shift inaugurated by the so- called `linguistic turn.' Here, thinkers contested what Kant took for granted; namely that `constitutive interpretations' (cognitions/concepts) formed a `reality' independently of language. The basic premise underpinning the `linguistic turn,' therefore, is that language (signification) and `reality' are inseparable. Henceforth, the possibility of final, enduring `constitutive interpretations' whose `truth,' in principle, is discoverable, depends on whether or not the language which mediates human rationality can form a complete and universal system. This question resurrects the very limit/possibility debate (in the form of a structuralism/postmodernism stand-off) that Kant thought he had resolved in mediating between rationalist and empiricist extremes. In contemporary terms, philosophers who, bound by either/or logic, wish to avoid the sceptical trap of `anything goes' postmodernism, must assume that language (signification) can form a complete and universal system. However, in his deconstructive readings of Husserl, Saussure and `structuralism,' Derrida demonstrates the untenability of this assumption. At the same time, he shows that the sceptical `alternative' may be avoided by recognising the limitations of `either/or' logic. Again, Derrida's thinking may be traced to Kant's; this time to his analysis of the `first antinomy.' In accordance with Kant's analysis here of what is ultimately the logic of `complex systems' (Cilliers), Derrida offers a `logos of difference,' which skirts the strictures of structuralism while avoiding the trap of postmodern scepticism by accommodating both moments of limit and possibility in an indissoluble interplay.
- Full Text:
- Date Issued: 1999
A preliminary investigation into the patterns of performance on a computerized adaptive test battery implications for admissions and placement
- Authors: Vorster, Marlene
- Date: 2002
- Subjects: Universities and colleges -- Admission , Advanced placement programs (Education) , Computer adaptive testing , Universities and colleges -- Entrance requirements
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11030 , http://hdl.handle.net/10948/285 , Universities and colleges -- Admission , Advanced placement programs (Education) , Computer adaptive testing , Universities and colleges -- Entrance requirements
- Description: The fallibility of human judgment in the making of decisions requires the use of tests to enhance decision-making processes. Although testing is surrounded with issues of bias and fairness, it remains the best means of facilitating decisions over more subjective alternatives. As a country in transition, all facets of South African society are being transformed. The changes taking place within the tertiary education system to redress the legacy of Apartheid, coincide with an international trend of transforming higher education. One important area that is being transformed relates to university entrance requirements and admissions procedures. In South Africa, these were traditionally based on matriculation performance, which has been found to be a more variable predictor of academic success for historically disadvantaged students. Alternative or revised admissions procedures have been implemented at universities throughout the country, in conjunction with academic development programmes. However, it is argued in this dissertation that a paradigm shift is necessary to conceptualise admissions and placement assessment in a developmentally oriented way. Furthermore, it is motivated that it is important to keep abreast of advances in theory, such as item response theory (IRT) and technology, such as computerized adaptive testing (CAT), in test development to enhance the effectiveness of selecting and placing learners in tertiary programmes. This study focuses on investigating the use of the Accuplacer Computerized Placement Tests (CPTs), an adaptive test battery that was developed in the USA, to facilitate unbiased and fair admissions, placement and development decisions in the transforming South African context. The battery has been implemented at a university in the Eastern Cape and its usefulness was investigated for 193 participants, divided into two groups of degree programmes, depending on whether or not admission to the degree required mathematics as a matriculation subject. Mathematics based degree programme learners (n = 125) wrote three and non-mathematics based degree programme learners (n = 68) wrote two tests of the Accuplacer test battery. Correlations were computed between the Accuplacer scores and matriculation performance, and between the Accuplacer scores, matriculation performance and academic results. All yielded significant positive relationships excepting for the one subtest of the Accuplacer with academic performance for the non-mathematics based degree group. Multiple correlations for both groups indicated that the Accuplacer scores and matriculation results contribute unique information about academic performance. Cluster analysis for both groups yielded three underlying patterns of performance in the data sets. An attempt was made to validate the cluster groups internally through a MANOVA and single-factor ANOVAs. It was found that Accuplacer subtests and matriculation results do discriminate to an extent among clusters of learners in both groups of degree programmes investigated. Clusters were described in terms of demographic information and it was determined that the factors of culture and home language and how they relate to cluster group membership need further investigation. The main suggestion flowing from these findings is that an attempt be made to confirm the results with a larger sample size and for different cultural and language groups.
- Full Text:
- Date Issued: 2002
- Authors: Vorster, Marlene
- Date: 2002
- Subjects: Universities and colleges -- Admission , Advanced placement programs (Education) , Computer adaptive testing , Universities and colleges -- Entrance requirements
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11030 , http://hdl.handle.net/10948/285 , Universities and colleges -- Admission , Advanced placement programs (Education) , Computer adaptive testing , Universities and colleges -- Entrance requirements
- Description: The fallibility of human judgment in the making of decisions requires the use of tests to enhance decision-making processes. Although testing is surrounded with issues of bias and fairness, it remains the best means of facilitating decisions over more subjective alternatives. As a country in transition, all facets of South African society are being transformed. The changes taking place within the tertiary education system to redress the legacy of Apartheid, coincide with an international trend of transforming higher education. One important area that is being transformed relates to university entrance requirements and admissions procedures. In South Africa, these were traditionally based on matriculation performance, which has been found to be a more variable predictor of academic success for historically disadvantaged students. Alternative or revised admissions procedures have been implemented at universities throughout the country, in conjunction with academic development programmes. However, it is argued in this dissertation that a paradigm shift is necessary to conceptualise admissions and placement assessment in a developmentally oriented way. Furthermore, it is motivated that it is important to keep abreast of advances in theory, such as item response theory (IRT) and technology, such as computerized adaptive testing (CAT), in test development to enhance the effectiveness of selecting and placing learners in tertiary programmes. This study focuses on investigating the use of the Accuplacer Computerized Placement Tests (CPTs), an adaptive test battery that was developed in the USA, to facilitate unbiased and fair admissions, placement and development decisions in the transforming South African context. The battery has been implemented at a university in the Eastern Cape and its usefulness was investigated for 193 participants, divided into two groups of degree programmes, depending on whether or not admission to the degree required mathematics as a matriculation subject. Mathematics based degree programme learners (n = 125) wrote three and non-mathematics based degree programme learners (n = 68) wrote two tests of the Accuplacer test battery. Correlations were computed between the Accuplacer scores and matriculation performance, and between the Accuplacer scores, matriculation performance and academic results. All yielded significant positive relationships excepting for the one subtest of the Accuplacer with academic performance for the non-mathematics based degree group. Multiple correlations for both groups indicated that the Accuplacer scores and matriculation results contribute unique information about academic performance. Cluster analysis for both groups yielded three underlying patterns of performance in the data sets. An attempt was made to validate the cluster groups internally through a MANOVA and single-factor ANOVAs. It was found that Accuplacer subtests and matriculation results do discriminate to an extent among clusters of learners in both groups of degree programmes investigated. Clusters were described in terms of demographic information and it was determined that the factors of culture and home language and how they relate to cluster group membership need further investigation. The main suggestion flowing from these findings is that an attempt be made to confirm the results with a larger sample size and for different cultural and language groups.
- Full Text:
- Date Issued: 2002
A revision of a section of the hearing and speech scale of the Griffiths Scales of Mental Development
- Authors: Kotras, Nicole
- Date: 2004
- Subjects: Griffiths scales of mental development , Psychological tests for children
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11022 , http://hdl.handle.net/10948/350 , Griffiths scales of mental development , Psychological tests for children
- Description: Since the introduction of the Griffiths Scales of Mental Development (Griffiths Scales) in the United Kingdom (1950) and South Africa (1977) they have become widely used and researched, both at a national and international level. Studies completed in South Africa have demonstrated the invaluable role the Griffiths Scales have fulfilled in the assessment of South African children of all cultural and socio-economic groups. However, research has indicated a need for the revision of the scales specifically relating to social and cultural factors that influence performance. The aim of this study was two-fold , namely: (i) to revise the 20 small pictures and the large picture of the Hearing and Speech Scale of the Griffiths Scales, making them more culturally relevant for the children of our contemporary world, and especially in South Africa; and (ii) to describe the performance of South African children, between 60 and 83 months of age, utilizing the revised pictures. For the qualitative component of the study a questionnaire pertaining to the small and large “Experimental pictures” was completed by the participants. The participants consisted of the executive committee members of the ARICD in the United Kingdom. Additionally 17 “expert “ Griffith's users and “lay-experts” working in early childhood development throughout South Africa, were included. Their responses were content analyzed and incorporated into the Experimental pictures. This resulted in the development of the Revised Griffiths pictures. The quantitative component of the study utilized two sample pools. Sample 1 (n=204) and Sample 2 (n=180) were comprised of pre-school children aged between 60 and 83 months. Sample 1 was utilized for the 20 small revised pictures and the large revised SA picture, while sample 2 was utilized for the 20 small revised pictures and the large revised United Kingdom/ European/Australian picture. Furthermore, both samples, consisted of children from all cultural, socio-economic, language, and gender groups. x The major findings of the present study were as follows: 1. Referring to sample 1, only the White and Indian pre-schoolers correctly identified a mean number of small pictures above that which was proposed by Griffiths (1960). The Coloured pre-schoolers almost identified Griffiths (1960) proposed number. 2. Referring to sample 2, all excepting the Black pre-schoolers correctly identified Griffiths’ (1960) proposed mean of small pictures. 3. All children from sample 1 and sample 2 were able to identify more stimuli from the large revised pictures, than was proposed by Griffiths (1960). 4. All four cultural groups from samples 1 and 2, elicited a mean number of descriptive words below Griffiths’ (1960) proposed criteria. 5. White pre-schoolers from sample 1 elicited a mean number of descriptive sentences above Griffiths’ (1960) proposed criteria. 6. White and Coloured pre-schoolers from sample 2 elicited a mean number of descriptive sentences above Griffiths’ (1960) proposed criteria. 7. All four cultural groups from sample 1 and sample 2, elicited a mean number of personal or possessive pronouns below Griffith's (1960) proposed criteria. 8. A general trend noted for the four cultural groups of both samples, was that the percentage of children who passed successive age-appropriate items, did not decrease stepwise as would be expected from the placement of items in order of difficulty. In view of the latter finding, it is recommended that for South African children the placement of the items for the small and large pictures of the Hearing and Speech Scale should be revised in terms of their order of difficulty. It is furthermore recommended that separate norms for South African children be established for the Hearing and Speech Scale
- Full Text:
- Authors: Kotras, Nicole
- Date: 2004
- Subjects: Griffiths scales of mental development , Psychological tests for children
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11022 , http://hdl.handle.net/10948/350 , Griffiths scales of mental development , Psychological tests for children
- Description: Since the introduction of the Griffiths Scales of Mental Development (Griffiths Scales) in the United Kingdom (1950) and South Africa (1977) they have become widely used and researched, both at a national and international level. Studies completed in South Africa have demonstrated the invaluable role the Griffiths Scales have fulfilled in the assessment of South African children of all cultural and socio-economic groups. However, research has indicated a need for the revision of the scales specifically relating to social and cultural factors that influence performance. The aim of this study was two-fold , namely: (i) to revise the 20 small pictures and the large picture of the Hearing and Speech Scale of the Griffiths Scales, making them more culturally relevant for the children of our contemporary world, and especially in South Africa; and (ii) to describe the performance of South African children, between 60 and 83 months of age, utilizing the revised pictures. For the qualitative component of the study a questionnaire pertaining to the small and large “Experimental pictures” was completed by the participants. The participants consisted of the executive committee members of the ARICD in the United Kingdom. Additionally 17 “expert “ Griffith's users and “lay-experts” working in early childhood development throughout South Africa, were included. Their responses were content analyzed and incorporated into the Experimental pictures. This resulted in the development of the Revised Griffiths pictures. The quantitative component of the study utilized two sample pools. Sample 1 (n=204) and Sample 2 (n=180) were comprised of pre-school children aged between 60 and 83 months. Sample 1 was utilized for the 20 small revised pictures and the large revised SA picture, while sample 2 was utilized for the 20 small revised pictures and the large revised United Kingdom/ European/Australian picture. Furthermore, both samples, consisted of children from all cultural, socio-economic, language, and gender groups. x The major findings of the present study were as follows: 1. Referring to sample 1, only the White and Indian pre-schoolers correctly identified a mean number of small pictures above that which was proposed by Griffiths (1960). The Coloured pre-schoolers almost identified Griffiths (1960) proposed number. 2. Referring to sample 2, all excepting the Black pre-schoolers correctly identified Griffiths’ (1960) proposed mean of small pictures. 3. All children from sample 1 and sample 2 were able to identify more stimuli from the large revised pictures, than was proposed by Griffiths (1960). 4. All four cultural groups from samples 1 and 2, elicited a mean number of descriptive words below Griffiths’ (1960) proposed criteria. 5. White pre-schoolers from sample 1 elicited a mean number of descriptive sentences above Griffiths’ (1960) proposed criteria. 6. White and Coloured pre-schoolers from sample 2 elicited a mean number of descriptive sentences above Griffiths’ (1960) proposed criteria. 7. All four cultural groups from sample 1 and sample 2, elicited a mean number of personal or possessive pronouns below Griffith's (1960) proposed criteria. 8. A general trend noted for the four cultural groups of both samples, was that the percentage of children who passed successive age-appropriate items, did not decrease stepwise as would be expected from the placement of items in order of difficulty. In view of the latter finding, it is recommended that for South African children the placement of the items for the small and large pictures of the Hearing and Speech Scale should be revised in terms of their order of difficulty. It is furthermore recommended that separate norms for South African children be established for the Hearing and Speech Scale
- Full Text:
A study of the airflow on the windward slope of a transverse dune in the Alexandria coastal dunefield
- Authors: Burkinshaw, Jennifer Ruth
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52734 , vital:43883
- Description: Our understanding of the evolution of dune morphology has been hampered by a lack of empirical observations of airflow behaviour over dune forms. Sand dunes intrude into the atmospheric boundary layer and convergence of streamlines results in an acceleration of airflow up the windward slopes of dunes. This study examines the airflow structure and corresponding bedform development on the windward slope of a 7 m high transverse dune on the edge of the Alexandria coastal dunefield, Algoa Bay, South Africa. The Alexandria dunefield is subjected to a trimodal wind regime, consisting of the dominant south-westerly which blows all year round, summer easterlies and winter northwesterlies. The morphology of the study dune, Dune13, is controlled by the easterlies and north-westerlies, and reverses seasonally with respect to these two winds. Seven section lines 30 m apart and normal to the dune crest were surveyed regularly over the period of a year to monitor the reversal process. Three detailed topographic surveys were also done during this period. Airflow behaviour was monitored during the year. Wind speed profiles on the windward slope of the dune were measured using 4 to 5 vertical arrays of anemometers positioned from the base of the dune to the crest on a 1 selected section line. Usually 4 to 5 anemometers were deployed in each vertical array, from a height of 6 to 10 cm above the surface, up to a height of 150 cm above the surface. Initially 8 microanemometers were available; ultimately 28 anemometers were run simultaneously. An independent weather station at an elevation of 6 m recorded the unaccelerated flow. Local gradient measurements and erosion and deposition rates were recorded along selected section lines. Strong summer easterly winds (14 m/sec at 1.4 m above the dune crest) were measured on a dune slope in the process of being transformed from a slipface to a stoss slope. The following winter, light north-westerly winds (typically B m/sec at 1.6 m above the dune crest) were measured on the new windward slope already reversed by the prevailing winter wind. Airflow data confirm the compression of airflow against the windward slope resulting in a non-logarithmic wind speed profile. Compression results in an increased shear velocity within 30 cm of the dune surface, and the dune slope is eroded. Higher up in the wind speed profile, shear velocity decreases to 0.1 m/sec. It is not known at what height the wind speed profile recovers from the intrusion of the dune into the boundary layer. High values of shear velocity (1.6 m/sec) above the rounded crestal area of the dune record the recovery of the wind speed profile from flow divergence, which is a response to the rapid reduction of dune gradient and is accompanied by deposition of sand in this region. 2 The erosion pin data act as a simple and sensitive test for changes in gradient, reflecting the dune's response to changes in the airflow regime. The shape of the dune plays a major role in determining the extent of the compression and the distribution of shear velocity up the slope. Increased shear velocity is experienced on that part of the slope which is nonaerodynamic with respect to the prevailing wind. Under unidirectional conditions, feedback between flow and form results ultimately in a slope with a curvature such that shear velocity increases systematically upslope. The survey data and erosion pin data record the reversal process as the dune achieves a new steady state during each wind season. The existence of a non-logarithmic wind speed profile makes it difficult to know what relevant measure of shear velocity is to be used in sand transport equations. Future work should include wind speed measurements within 10 cm of the surface. An ideal study modelling aeolian bedform development would utilise wind tunnel measurements, combined with field measurements such as obtained in this study, for comparison with numerical modelling. The study needs to be extended to 3-dimensional airflow measurements. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Burkinshaw, Jennifer Ruth
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52734 , vital:43883
- Description: Our understanding of the evolution of dune morphology has been hampered by a lack of empirical observations of airflow behaviour over dune forms. Sand dunes intrude into the atmospheric boundary layer and convergence of streamlines results in an acceleration of airflow up the windward slopes of dunes. This study examines the airflow structure and corresponding bedform development on the windward slope of a 7 m high transverse dune on the edge of the Alexandria coastal dunefield, Algoa Bay, South Africa. The Alexandria dunefield is subjected to a trimodal wind regime, consisting of the dominant south-westerly which blows all year round, summer easterlies and winter northwesterlies. The morphology of the study dune, Dune13, is controlled by the easterlies and north-westerlies, and reverses seasonally with respect to these two winds. Seven section lines 30 m apart and normal to the dune crest were surveyed regularly over the period of a year to monitor the reversal process. Three detailed topographic surveys were also done during this period. Airflow behaviour was monitored during the year. Wind speed profiles on the windward slope of the dune were measured using 4 to 5 vertical arrays of anemometers positioned from the base of the dune to the crest on a 1 selected section line. Usually 4 to 5 anemometers were deployed in each vertical array, from a height of 6 to 10 cm above the surface, up to a height of 150 cm above the surface. Initially 8 microanemometers were available; ultimately 28 anemometers were run simultaneously. An independent weather station at an elevation of 6 m recorded the unaccelerated flow. Local gradient measurements and erosion and deposition rates were recorded along selected section lines. Strong summer easterly winds (14 m/sec at 1.4 m above the dune crest) were measured on a dune slope in the process of being transformed from a slipface to a stoss slope. The following winter, light north-westerly winds (typically B m/sec at 1.6 m above the dune crest) were measured on the new windward slope already reversed by the prevailing winter wind. Airflow data confirm the compression of airflow against the windward slope resulting in a non-logarithmic wind speed profile. Compression results in an increased shear velocity within 30 cm of the dune surface, and the dune slope is eroded. Higher up in the wind speed profile, shear velocity decreases to 0.1 m/sec. It is not known at what height the wind speed profile recovers from the intrusion of the dune into the boundary layer. High values of shear velocity (1.6 m/sec) above the rounded crestal area of the dune record the recovery of the wind speed profile from flow divergence, which is a response to the rapid reduction of dune gradient and is accompanied by deposition of sand in this region. 2 The erosion pin data act as a simple and sensitive test for changes in gradient, reflecting the dune's response to changes in the airflow regime. The shape of the dune plays a major role in determining the extent of the compression and the distribution of shear velocity up the slope. Increased shear velocity is experienced on that part of the slope which is nonaerodynamic with respect to the prevailing wind. Under unidirectional conditions, feedback between flow and form results ultimately in a slope with a curvature such that shear velocity increases systematically upslope. The survey data and erosion pin data record the reversal process as the dune achieves a new steady state during each wind season. The existence of a non-logarithmic wind speed profile makes it difficult to know what relevant measure of shear velocity is to be used in sand transport equations. Future work should include wind speed measurements within 10 cm of the surface. An ideal study modelling aeolian bedform development would utilise wind tunnel measurements, combined with field measurements such as obtained in this study, for comparison with numerical modelling. The study needs to be extended to 3-dimensional airflow measurements. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text:
- Date Issued: 2021-04
A study of the structural geology of the Witteberg Group and lowermost Karoo Supergroup, Darlington Dam, Jansenville District, Eastern Cape
- Goossens, Angelique Emily Maria
- Authors: Goossens, Angelique Emily Maria
- Date: 2003
- Subjects: Folds (Geology) -- South Africa -- Eastern Cape , Faults (Geology) -- South Africa -- Eastern Cape , Geology, Structural -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11071 , http://hdl.handle.net/10948/291 , Folds (Geology) -- South Africa -- Eastern Cape , Faults (Geology) -- South Africa -- Eastern Cape , Geology, Structural -- South Africa -- Eastern Cape
- Description: A number of outcrops of the Witteberg Group and lowermost Karoo Supergroup rocks were studied in the area south of the Darlington Dam, Jansenville District, with the aim of documenting structural characteristics of the area. All lithologies are folded with fold styles varying from gentle to near isoclinal (based on interlimb angle). Fold axes are either sub-horizontal or plunging at gentle to moderate angles whereas axial planes dip gently to vertically (predominantly steep to sub-vertical). Folds verge predominantly towards the north but where southward verging they are associated with faulting or strongly folded areas. Folds plunge gently to the east-southeast and west-northwest. The area consists of a large anticlinorium with both first and second order folds occurring. Eastwest striking faults occur in the study area and are classified as normal, reverse and thrust faults. A study of the joint sets shows that there are four dominant joint directions, namely 18o, 33o, 97o and 107o (in order from least to most important). An interpretation of the tectonic history is presented in which the relationships between faults and folds show that faults formed during and after folding. Folding, and reverse and thrust faulting, occurred during the compressional events that formed the Cape Fold Belt, whereas the normal faults formed during the relaxation of these compressional forces or during the break-up of Gondwana.
- Full Text:
- Date Issued: 2003
- Authors: Goossens, Angelique Emily Maria
- Date: 2003
- Subjects: Folds (Geology) -- South Africa -- Eastern Cape , Faults (Geology) -- South Africa -- Eastern Cape , Geology, Structural -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11071 , http://hdl.handle.net/10948/291 , Folds (Geology) -- South Africa -- Eastern Cape , Faults (Geology) -- South Africa -- Eastern Cape , Geology, Structural -- South Africa -- Eastern Cape
- Description: A number of outcrops of the Witteberg Group and lowermost Karoo Supergroup rocks were studied in the area south of the Darlington Dam, Jansenville District, with the aim of documenting structural characteristics of the area. All lithologies are folded with fold styles varying from gentle to near isoclinal (based on interlimb angle). Fold axes are either sub-horizontal or plunging at gentle to moderate angles whereas axial planes dip gently to vertically (predominantly steep to sub-vertical). Folds verge predominantly towards the north but where southward verging they are associated with faulting or strongly folded areas. Folds plunge gently to the east-southeast and west-northwest. The area consists of a large anticlinorium with both first and second order folds occurring. Eastwest striking faults occur in the study area and are classified as normal, reverse and thrust faults. A study of the joint sets shows that there are four dominant joint directions, namely 18o, 33o, 97o and 107o (in order from least to most important). An interpretation of the tectonic history is presented in which the relationships between faults and folds show that faults formed during and after folding. Folding, and reverse and thrust faulting, occurred during the compressional events that formed the Cape Fold Belt, whereas the normal faults formed during the relaxation of these compressional forces or during the break-up of Gondwana.
- Full Text:
- Date Issued: 2003
Affirmative action in terms of the Empolyment Equity Act
- Authors: Mgcodo, Yolanda Thandile
- Date: 2004
- Subjects: Affirmative action programs -- Law and legislation -- South Africa , Discrimination in employment -- Law and legislation -- South Africa , South Africa. Employment Equity Act -- 1998
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11048 , http://hdl.handle.net/10948/356 , Affirmative action programs -- Law and legislation -- South Africa , Discrimination in employment -- Law and legislation -- South Africa , South Africa. Employment Equity Act -- 1998
- Description: The term affirmative action originated in the United States some 30 years ago to describe a process of liberating minority groups. The objective of affirmative action within an organisational context, is to democratise the workplace by enabling members of previously disadvantaged groups to progress higher up the ranks of the corporate world. The affirmative action drive only took off in South Africa when it became part of the democratisation process and the focus was directed towards liberating the historically disadvantaged black majority. Prior to 1994, the reasons for implementing affirmative action programmes were largely political because of the race-based discrimination. Historically disadvantaged people were a minority in senior positions, the reason being that although the blacks were given a chance to compete with their white counterparts, due to their poor education standards and lack of experience only a few was appointed. The Employment Equity Act 55 of 1998 aims to correct the demographic imbalances in the nation’s workforce by compelling employers to remove barriers to advancement of blacks, coloureds, Indians, women and disabled, and actively to advance them in all categories of employment by affirmative action. The Employment Equity Act consists of two main sections. The first replaces and refines the prohibition on unfair discrimination in item 2(1)(a) of Schedule 7 of the Labour Relations Act. The second aspect deals with imposing a duty to the employers to adopt affirmative action programmes. The Employment Equity Act places a positive obligation on all employers “to promote equal opportunity in the workplace by eliminating unfair discrimination in any employment policy or practice”. Where unfair discrimination is alleged, the onus of proving that discrimination is fair, or practice is not discriminatory at all, rests upon the employer. Disputes about unfair discrimination must be referred to the CCMA, and if not settled by conciliation, to the Labour Court, which has the power to order compensation or the payment iv of damages, or to direct the employer to take steps to prevent the same unfair discrimination or similar practice occurring in the future in respect of other employees. The second section of the Employment Equity Act deals with the imposition of the duty to designated employers to adopt affirmative action programmes. All employers with more than 50 employees, or which have annual turnovers equal to or above the annual turnovers for small businesses of their class, municipalities, organs of state, and those designated as such by collective agreement, must implement affirmative action measures for people from designated groups. This entails consulting with employers, conducting an analysis of employment policies, practices, procedures and the working environment to identify barriers, drawing up employment equity plans and reporting thereafter to the Director-General of the Department of Labour on progress made in implementing the plan. Any employee may bring alleged contraventions of the Act to the attention of the employer, another employee, or any trade union, workplace forum, labour inspector or the Director- General of the Employment Equity Commission. Labour inspectors appointed under the Basic Conditions of Employment Act may enter and inspect employer’s properties and documents, and are responsible for ensuring that the employer has consulted with employees as required, conducted the pre-equity plan analysis prepared its plan and is implementing it, submitted and published its reports, set up the necessary managerial infrastructure, and informed its employees of progress. Should employers be found not to have complied with these requirements, labour inspectors must request a written undertaking that they will do so. If an employer fails to give such an undertaking, the labour inspector can issue a compliance order setting out inter alia what steps the employer must take and when, and the maximum fine, if any, that can be imposed if the employer fails to comply. If the employer does not pay attention to the compliance order within the prescribed period, the Director-General may apply to have it made an order of the Labour Court. The Director-General may also conduct independent ad hoc reviews of selected designated employers. Failure by an employer to comply with the provision of the Act lead to the employer being liable for the contravention of the Act.
- Full Text:
- Date Issued: 2004
- Authors: Mgcodo, Yolanda Thandile
- Date: 2004
- Subjects: Affirmative action programs -- Law and legislation -- South Africa , Discrimination in employment -- Law and legislation -- South Africa , South Africa. Employment Equity Act -- 1998
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11048 , http://hdl.handle.net/10948/356 , Affirmative action programs -- Law and legislation -- South Africa , Discrimination in employment -- Law and legislation -- South Africa , South Africa. Employment Equity Act -- 1998
- Description: The term affirmative action originated in the United States some 30 years ago to describe a process of liberating minority groups. The objective of affirmative action within an organisational context, is to democratise the workplace by enabling members of previously disadvantaged groups to progress higher up the ranks of the corporate world. The affirmative action drive only took off in South Africa when it became part of the democratisation process and the focus was directed towards liberating the historically disadvantaged black majority. Prior to 1994, the reasons for implementing affirmative action programmes were largely political because of the race-based discrimination. Historically disadvantaged people were a minority in senior positions, the reason being that although the blacks were given a chance to compete with their white counterparts, due to their poor education standards and lack of experience only a few was appointed. The Employment Equity Act 55 of 1998 aims to correct the demographic imbalances in the nation’s workforce by compelling employers to remove barriers to advancement of blacks, coloureds, Indians, women and disabled, and actively to advance them in all categories of employment by affirmative action. The Employment Equity Act consists of two main sections. The first replaces and refines the prohibition on unfair discrimination in item 2(1)(a) of Schedule 7 of the Labour Relations Act. The second aspect deals with imposing a duty to the employers to adopt affirmative action programmes. The Employment Equity Act places a positive obligation on all employers “to promote equal opportunity in the workplace by eliminating unfair discrimination in any employment policy or practice”. Where unfair discrimination is alleged, the onus of proving that discrimination is fair, or practice is not discriminatory at all, rests upon the employer. Disputes about unfair discrimination must be referred to the CCMA, and if not settled by conciliation, to the Labour Court, which has the power to order compensation or the payment iv of damages, or to direct the employer to take steps to prevent the same unfair discrimination or similar practice occurring in the future in respect of other employees. The second section of the Employment Equity Act deals with the imposition of the duty to designated employers to adopt affirmative action programmes. All employers with more than 50 employees, or which have annual turnovers equal to or above the annual turnovers for small businesses of their class, municipalities, organs of state, and those designated as such by collective agreement, must implement affirmative action measures for people from designated groups. This entails consulting with employers, conducting an analysis of employment policies, practices, procedures and the working environment to identify barriers, drawing up employment equity plans and reporting thereafter to the Director-General of the Department of Labour on progress made in implementing the plan. Any employee may bring alleged contraventions of the Act to the attention of the employer, another employee, or any trade union, workplace forum, labour inspector or the Director- General of the Employment Equity Commission. Labour inspectors appointed under the Basic Conditions of Employment Act may enter and inspect employer’s properties and documents, and are responsible for ensuring that the employer has consulted with employees as required, conducted the pre-equity plan analysis prepared its plan and is implementing it, submitted and published its reports, set up the necessary managerial infrastructure, and informed its employees of progress. Should employers be found not to have complied with these requirements, labour inspectors must request a written undertaking that they will do so. If an employer fails to give such an undertaking, the labour inspector can issue a compliance order setting out inter alia what steps the employer must take and when, and the maximum fine, if any, that can be imposed if the employer fails to comply. If the employer does not pay attention to the compliance order within the prescribed period, the Director-General may apply to have it made an order of the Labour Court. The Director-General may also conduct independent ad hoc reviews of selected designated employers. Failure by an employer to comply with the provision of the Act lead to the employer being liable for the contravention of the Act.
- Full Text:
- Date Issued: 2004
Algorithms for the solution of the quadratic programming problem
- Authors: Vankova, Martina
- Date: 2004
- Subjects: Quadratic programming , Nonlinear programming , Algorithms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11086 , http://hdl.handle.net/10948/348 , Quadratic programming , Nonlinear programming , Algorithms
- Description: The purpose of this dissertation was to provide a review of the theory of Optimization, in particular quadratic programming, and the algorithms suitable for solving both convex and non-convex quadratic programming problems. Optimization problems arise in a wide variety of fields and many can be effectively modeled with linear equations. However, there are problems for which linear models are not sufficient thus creating a need for non-linear systems. This dissertation includes a literature study of the formal theory necessary for understanding optimization and an investigation of the algorithms available for solving a special class of the non-linear programming problem, namely the quadratic programming problem. It was not the intention of this dissertation to discuss all possible algorithms for solving the quadratic programming problem, therefore certain algorithms for convex and non-convex quadratic programming problems were selected for a detailed discussion in the dissertation. Some of the algorithms were selected arbitrarily, because limited information was available comparing the efficiency of the various algorithms. Algorithms available for solving general non-linear programming problems were also included and briefly discussed as they can be used to solve quadratic programming problems. A number of algorithms were then selected for evaluation, depending on the frequency of use in practice and the availability of software implementing these algorithms. The evaluation included a theoretical and quantitative comparison of the algorithms. The quantitative results were analyzed and discussed and it was shown that the results supported the theoretical comparison. It was also shown that it is difficult to conclude that one algorithm is better than another as the efficiency of an algorithm greatly depends on the size of the problem, the complexity of an algorithm and many other implementation issues. Optimization problems arise continuously in a wide range of fields and thus create the need for effective methods of solving them. This dissertation provides the fundamental theory necessary for the understanding of optimization problems, with particular reference to quadratic programming problems and the algorithms that solve such problems. Keywords: Quadratic Programming, Quadratic Programming Algorithms, Optimization, Non-linear Programming, Convex, Non-convex.
- Full Text:
- Date Issued: 2004
- Authors: Vankova, Martina
- Date: 2004
- Subjects: Quadratic programming , Nonlinear programming , Algorithms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11086 , http://hdl.handle.net/10948/348 , Quadratic programming , Nonlinear programming , Algorithms
- Description: The purpose of this dissertation was to provide a review of the theory of Optimization, in particular quadratic programming, and the algorithms suitable for solving both convex and non-convex quadratic programming problems. Optimization problems arise in a wide variety of fields and many can be effectively modeled with linear equations. However, there are problems for which linear models are not sufficient thus creating a need for non-linear systems. This dissertation includes a literature study of the formal theory necessary for understanding optimization and an investigation of the algorithms available for solving a special class of the non-linear programming problem, namely the quadratic programming problem. It was not the intention of this dissertation to discuss all possible algorithms for solving the quadratic programming problem, therefore certain algorithms for convex and non-convex quadratic programming problems were selected for a detailed discussion in the dissertation. Some of the algorithms were selected arbitrarily, because limited information was available comparing the efficiency of the various algorithms. Algorithms available for solving general non-linear programming problems were also included and briefly discussed as they can be used to solve quadratic programming problems. A number of algorithms were then selected for evaluation, depending on the frequency of use in practice and the availability of software implementing these algorithms. The evaluation included a theoretical and quantitative comparison of the algorithms. The quantitative results were analyzed and discussed and it was shown that the results supported the theoretical comparison. It was also shown that it is difficult to conclude that one algorithm is better than another as the efficiency of an algorithm greatly depends on the size of the problem, the complexity of an algorithm and many other implementation issues. Optimization problems arise continuously in a wide range of fields and thus create the need for effective methods of solving them. This dissertation provides the fundamental theory necessary for the understanding of optimization problems, with particular reference to quadratic programming problems and the algorithms that solve such problems. Keywords: Quadratic Programming, Quadratic Programming Algorithms, Optimization, Non-linear Programming, Convex, Non-convex.
- Full Text:
- Date Issued: 2004
An analysis of group adverse impact in selection strategies of a communications company
- Authors: Bradfield, Claire Caroline
- Date: 2004
- Subjects: Telecommunication -- Employees -- Selection and appointment -- South Africa , Employee selection -- South Africa , Discrimination in employment -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10993 , http://hdl.handle.net/10948/361 , Telecommunication -- Employees -- Selection and appointment -- South Africa , Employee selection -- South Africa , Discrimination in employment -- South Africa
- Description: An overview of the literature indicates that there is a real and pressing need to explore the concept of adverse impact in more detail. The Employment Equity Act of 1998 prioritises the issue of group representivity in staff selection and although there are merits in enforcing an Affirmative Action policy, an objective assessment of the inherent requirements of job applicants is still a constitutional and procedural outcome. There is no simple mechanism that can be used to determine the manifestation of adverse impact. However, evidence thereof can be most useful in securing fairness in selection and employment decisions. There is a distinct need to examine the matter of adverse impact and its implications in the South African context. South Africa is confronted with a labour force that is growing dramatically and changing significantly. The demographic trends in our dynamically changing labour markets are likely to amplify skill and ability differences between the resulting contradictory goals of equal opportunity based on individual merit and equal employment results for subgroups of populations. Three selection strategies of a communications company were used as a basis for the assessment of adverse impact. The total population of the Call Centre selection strategy was 150. Seven instruments and measures were utilised in the study, namely, a job analysis, pre-screening exercise, psychometric ability tests, role-play simulation, structured interview, job compatibility questionnaire and a performance evaluation. The total population of the Operator Services selection strategy was 139. Five psychometric instruments were utilised in the study. The total population of the Female Leadership Development Programme selection strategy was 471. Three psychometric instruments were utilised in the study. The Adverse Impact Model was applied to each of the aforementioned strategies. In terms of the definition, adverse impact exists if the selection ratio associated with a particular passing score on a test for one sub-group of job applicants is less than 4/5th’s or 80% of the selection ration for the largest sub-group of applicants. 13 The results of the study indicate that adverse impact occurred in the following instances. In the Call Centre selection strategy, there was evidence of adverse impact in the racial analysis in the ability testing stage. There was also evidence of adverse impact in the gender analysis during this stage. There was no evidence of adverse impact in either the racial or gender analyses during the interview stage. There was no evidence of adverse impact in the racial analysis during the appointment stage. There was however evidence of adverse impact in the gender analysis during the appointment stage. The Female Leadership Development Programme selection strategy revealed evidence of adverse impact in the racial analysis during the appointment stage. The Operator Services selection strategy revealed an adverse impact in both the racial and gender analyses during the testing stage. The issue of adverse impact is obviously controversial. However, data obtained from this process will provide for informative analysis.
- Full Text:
- Date Issued: 2004
- Authors: Bradfield, Claire Caroline
- Date: 2004
- Subjects: Telecommunication -- Employees -- Selection and appointment -- South Africa , Employee selection -- South Africa , Discrimination in employment -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10993 , http://hdl.handle.net/10948/361 , Telecommunication -- Employees -- Selection and appointment -- South Africa , Employee selection -- South Africa , Discrimination in employment -- South Africa
- Description: An overview of the literature indicates that there is a real and pressing need to explore the concept of adverse impact in more detail. The Employment Equity Act of 1998 prioritises the issue of group representivity in staff selection and although there are merits in enforcing an Affirmative Action policy, an objective assessment of the inherent requirements of job applicants is still a constitutional and procedural outcome. There is no simple mechanism that can be used to determine the manifestation of adverse impact. However, evidence thereof can be most useful in securing fairness in selection and employment decisions. There is a distinct need to examine the matter of adverse impact and its implications in the South African context. South Africa is confronted with a labour force that is growing dramatically and changing significantly. The demographic trends in our dynamically changing labour markets are likely to amplify skill and ability differences between the resulting contradictory goals of equal opportunity based on individual merit and equal employment results for subgroups of populations. Three selection strategies of a communications company were used as a basis for the assessment of adverse impact. The total population of the Call Centre selection strategy was 150. Seven instruments and measures were utilised in the study, namely, a job analysis, pre-screening exercise, psychometric ability tests, role-play simulation, structured interview, job compatibility questionnaire and a performance evaluation. The total population of the Operator Services selection strategy was 139. Five psychometric instruments were utilised in the study. The total population of the Female Leadership Development Programme selection strategy was 471. Three psychometric instruments were utilised in the study. The Adverse Impact Model was applied to each of the aforementioned strategies. In terms of the definition, adverse impact exists if the selection ratio associated with a particular passing score on a test for one sub-group of job applicants is less than 4/5th’s or 80% of the selection ration for the largest sub-group of applicants. 13 The results of the study indicate that adverse impact occurred in the following instances. In the Call Centre selection strategy, there was evidence of adverse impact in the racial analysis in the ability testing stage. There was also evidence of adverse impact in the gender analysis during this stage. There was no evidence of adverse impact in either the racial or gender analyses during the interview stage. There was no evidence of adverse impact in the racial analysis during the appointment stage. There was however evidence of adverse impact in the gender analysis during the appointment stage. The Female Leadership Development Programme selection strategy revealed evidence of adverse impact in the racial analysis during the appointment stage. The Operator Services selection strategy revealed an adverse impact in both the racial and gender analyses during the testing stage. The issue of adverse impact is obviously controversial. However, data obtained from this process will provide for informative analysis.
- Full Text:
- Date Issued: 2004
An appraisal of strike law in South Africa
- Authors: Crompton, Mark Stanley
- Date: 2005
- Subjects: Strikes and lockouts -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11038 , http://hdl.handle.net/10948/379 , Strikes and lockouts -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa
- Description: The recent amendments made to employment laws and in particular the rewriting of the South African Labour Relations Act has brought into focus the diverse and conflicting interests of employers and employees, which is a concern of labour law analysts. This appraisal of South African of strike law examines the statutory and judicially established labour law in regard to the phenomenon of collective industrial action by employees and the regulation of its occurrence. Historical developments in strike law are traced from the early 1900’s. A period of segregated trade unionism, led ultimately to the introduction of a more inclusive system of regulation, which has in turn been modified to bring the law into line with the new constitutional imperatives. Industrial action occurred, often unregulated and regardless of statutory limitations, and in particular that industrial action which related to mass protest action, now recognized as a specific form of strike. The now repealed Labour Relations Act 28 of 1956 is examined with regard to its strike regulating provisions, and identification of what were then new, unrecognized forms of strike action. It has allowed concepts and principles to be developed, under the unfair labour practice jurisdiction of the Industrial Court, much of which has been incorporated in the new Labour Relations Act. The legislation on strike law, which has been developed over the years, has been refined by the constitutional imperatives introduced to the national legal system. The relevant aspects of the new Constitution Act 108 of 1996 and its pervasive effect on strike law are examined. The right to strike in South African labour law, together with the protection of collective bargaining, is now constitutionally entrenched, and the right to strike is now accepted as a necessary adjunct to collective bargaining. It is necessary to give effect to the Constitution in national legislation, and the Labour Relations Act 66 of 1995 endeavours to accomplish this in chapter IV in regard to strike law, which, it could be argued, limits rather than gives expression to the right to strike. iii The Labour Relations Act of 1995 is then discussed with reference to protected and prohibited strikes, and unregulated strike action. It will be evident that the Act has endeavoured to contain unprocedural and productivity draining industrial action, by subjecting rights disputes to arbitration and Labour Court adjudication, subject to certain exceptions. The recourse to lock-out, as the employer’s prerogative and general corollary of strike action, is briefly discussed. The case law relating to strikes is discussed in respect of both the 1956 Act and the new Labour Relations Act of 1995. Among the issues explored are the strike provisions which have been developed in statute and labour related common law, such as the identification of issues in dispute, notice of strike, the issuing of ultimatums, the audi altarem partem rule and the court’s approach to protected and unprotected strikes. The intention is to determine trends resulting from amendments to the law and draw inferences regarding, in particular, the unregulated form of strikes that occur within the scope of the protections offered by the Act. It is the intention to determine whether the desired effect has been achieved by implementing legislative reforms in response to public policy considerations.
- Full Text:
- Date Issued: 2005
- Authors: Crompton, Mark Stanley
- Date: 2005
- Subjects: Strikes and lockouts -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11038 , http://hdl.handle.net/10948/379 , Strikes and lockouts -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa
- Description: The recent amendments made to employment laws and in particular the rewriting of the South African Labour Relations Act has brought into focus the diverse and conflicting interests of employers and employees, which is a concern of labour law analysts. This appraisal of South African of strike law examines the statutory and judicially established labour law in regard to the phenomenon of collective industrial action by employees and the regulation of its occurrence. Historical developments in strike law are traced from the early 1900’s. A period of segregated trade unionism, led ultimately to the introduction of a more inclusive system of regulation, which has in turn been modified to bring the law into line with the new constitutional imperatives. Industrial action occurred, often unregulated and regardless of statutory limitations, and in particular that industrial action which related to mass protest action, now recognized as a specific form of strike. The now repealed Labour Relations Act 28 of 1956 is examined with regard to its strike regulating provisions, and identification of what were then new, unrecognized forms of strike action. It has allowed concepts and principles to be developed, under the unfair labour practice jurisdiction of the Industrial Court, much of which has been incorporated in the new Labour Relations Act. The legislation on strike law, which has been developed over the years, has been refined by the constitutional imperatives introduced to the national legal system. The relevant aspects of the new Constitution Act 108 of 1996 and its pervasive effect on strike law are examined. The right to strike in South African labour law, together with the protection of collective bargaining, is now constitutionally entrenched, and the right to strike is now accepted as a necessary adjunct to collective bargaining. It is necessary to give effect to the Constitution in national legislation, and the Labour Relations Act 66 of 1995 endeavours to accomplish this in chapter IV in regard to strike law, which, it could be argued, limits rather than gives expression to the right to strike. iii The Labour Relations Act of 1995 is then discussed with reference to protected and prohibited strikes, and unregulated strike action. It will be evident that the Act has endeavoured to contain unprocedural and productivity draining industrial action, by subjecting rights disputes to arbitration and Labour Court adjudication, subject to certain exceptions. The recourse to lock-out, as the employer’s prerogative and general corollary of strike action, is briefly discussed. The case law relating to strikes is discussed in respect of both the 1956 Act and the new Labour Relations Act of 1995. Among the issues explored are the strike provisions which have been developed in statute and labour related common law, such as the identification of issues in dispute, notice of strike, the issuing of ultimatums, the audi altarem partem rule and the court’s approach to protected and unprotected strikes. The intention is to determine trends resulting from amendments to the law and draw inferences regarding, in particular, the unregulated form of strikes that occur within the scope of the protections offered by the Act. It is the intention to determine whether the desired effect has been achieved by implementing legislative reforms in response to public policy considerations.
- Full Text:
- Date Issued: 2005
An assessment of bait availability, utilization and management guidelines in Eastern Cape estuaries
- Authors: Jooste, Jakobus Gerrit
- Date: 2003
- Subjects: Upogebia african -- Effects of sediments on -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Fishing baits -- Conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11073 , http://hdl.handle.net/10948/334 , Upogebia african -- Effects of sediments on -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Fishing baits -- Conservation -- South Africa -- Eastern Cape
- Description: Aspects around the management of benthic soft sediment bait organisms, with special focus on the mud prawn (Upogebia africana) of eastern Cape estuaries was investigated. The recreational linefishery of the Gamtoos estuary was described, and compared to previous studies. Target fish species was identified, and a large dependency on bait sourced from estuaries needed for the capture of these species was noted, especially for spotted grunter (Pomadasys commersonnii). A comparison between bait use, success and the natural diet of target fish species was also made. The structure and distribution of sediments in the old channel mud banks was described and compared with historical data. The influence of sediments on mud prawn distribution was investigated, but no significant interactions were found at the study site. The impacts of once-off pumping and digging events, and monthly trampling on the sediments and mud prawn population was studied over a 7-month period. Initial removal rates as well as recovery time varied significantly between the two collection methods, while the largest decline in prawn numbers (to zero) with no recovery visible after seven months was caused by trampling. All disturbances caused some alteration in sediment composition, but not to such an extent that the sediments became unfavorable for mud prawns. Trampling did, however, result in the compaction of sediments to such a degree that prawns could not construct burrows. Issues around current removal quotas of bait species as well as the creation of a small-scale commercial (SSC) bait selling operation at Swartkops estuary were critically evaluated, and suggestions for the future removal rates of mud prawns based on production export calculations were made. The distribution, size, sex ratios and number of gravid females occurring along a tidal gradient as well as along horizontal gradient of the mud bank during growth (January – March) and reproductive (September – October) periods was investigated. Changes in the distribution of females between the two study periods were significant, while the distribution of reproductively active females were closely linked to the low water mark (Lower tidal levels). Females occurring in this zone were also significantly larger than females occurring towards the back of the study site. Some minor changes along the horizontal gradient were also observed. The sediment compos ition of the mud bank was found not to play a role in this distribution, leading to the suggestion that exposure to ebb and flood tide currents could influence female prawn distributions. Management recommendations based on these observations were made.
- Full Text:
- Date Issued: 2003
- Authors: Jooste, Jakobus Gerrit
- Date: 2003
- Subjects: Upogebia african -- Effects of sediments on -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Fishing baits -- Conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11073 , http://hdl.handle.net/10948/334 , Upogebia african -- Effects of sediments on -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Fishing baits -- Conservation -- South Africa -- Eastern Cape
- Description: Aspects around the management of benthic soft sediment bait organisms, with special focus on the mud prawn (Upogebia africana) of eastern Cape estuaries was investigated. The recreational linefishery of the Gamtoos estuary was described, and compared to previous studies. Target fish species was identified, and a large dependency on bait sourced from estuaries needed for the capture of these species was noted, especially for spotted grunter (Pomadasys commersonnii). A comparison between bait use, success and the natural diet of target fish species was also made. The structure and distribution of sediments in the old channel mud banks was described and compared with historical data. The influence of sediments on mud prawn distribution was investigated, but no significant interactions were found at the study site. The impacts of once-off pumping and digging events, and monthly trampling on the sediments and mud prawn population was studied over a 7-month period. Initial removal rates as well as recovery time varied significantly between the two collection methods, while the largest decline in prawn numbers (to zero) with no recovery visible after seven months was caused by trampling. All disturbances caused some alteration in sediment composition, but not to such an extent that the sediments became unfavorable for mud prawns. Trampling did, however, result in the compaction of sediments to such a degree that prawns could not construct burrows. Issues around current removal quotas of bait species as well as the creation of a small-scale commercial (SSC) bait selling operation at Swartkops estuary were critically evaluated, and suggestions for the future removal rates of mud prawns based on production export calculations were made. The distribution, size, sex ratios and number of gravid females occurring along a tidal gradient as well as along horizontal gradient of the mud bank during growth (January – March) and reproductive (September – October) periods was investigated. Changes in the distribution of females between the two study periods were significant, while the distribution of reproductively active females were closely linked to the low water mark (Lower tidal levels). Females occurring in this zone were also significantly larger than females occurring towards the back of the study site. Some minor changes along the horizontal gradient were also observed. The sediment compos ition of the mud bank was found not to play a role in this distribution, leading to the suggestion that exposure to ebb and flood tide currents could influence female prawn distributions. Management recommendations based on these observations were made.
- Full Text:
- Date Issued: 2003
An assessment of selected non-water benefits of the Working for Water Programme in the Eastern and Southern Cape
- Authors: Du Plessis, Lily Lozelle
- Date: 2003
- Subjects: Water resources development -- South Africa -- Eastern Cape -- Cost effectiveness , Water resources development -- South Africa -- Southern Cape -- Cost effectiveness , Water conservation projects -- South Africa -- Eastern Cape -- Cost effectiveness , Water conservation projects -- South Africa -- Southern Cape -- Cost effectiveness , Land use -- Economic aspects -- South Africa -- Eastern Cape , Land use -- Economic aspects -- South Africa -- Southern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10991 , http://hdl.handle.net/10948/340 , Water resources development -- South Africa -- Eastern Cape -- Cost effectiveness , Water resources development -- South Africa -- Southern Cape -- Cost effectiveness , Water conservation projects -- South Africa -- Eastern Cape -- Cost effectiveness , Water conservation projects -- South Africa -- Southern Cape -- Cost effectiveness , Land use -- Economic aspects -- South Africa -- Eastern Cape , Land use -- Economic aspects -- South Africa -- Southern Cape
- Description: 1.1 Background to, and motivation for, the study: The Working for Water programme (WfW) is a public works programme designed to clear South Africa of water-consuming invasive alien tree and plants, and to replace them with low water consuming indigenous species. This would prevent a loss of more than 4000 million cubic metres water per annum from the hydrological cycle (DWAF, 1998). The economic viability of the programme has been established in the Western Cape and Kwazulu-Natal (van Wilgen, Little, Chapman, Görgens, Willems and Marais, 1997; Gilham and Haynes, 2001), but questioned in the Eastern and Southern Cape (Hosking, du Preez, Campbell, Wooldridge and du Plessis, 2002). Hosking et al. (2002) investigated the economic case for the programme by performing a Cost Benefit Analysis (CBA), based on increased water yield and livestock potential, on six selected sites in the Eastern and Southern Cape, viz. Albany, Kat River, Pot River, Tsitsikamma, Kouga and Port Elizabeth Driftsands.
- Full Text:
- Date Issued: 2003
- Authors: Du Plessis, Lily Lozelle
- Date: 2003
- Subjects: Water resources development -- South Africa -- Eastern Cape -- Cost effectiveness , Water resources development -- South Africa -- Southern Cape -- Cost effectiveness , Water conservation projects -- South Africa -- Eastern Cape -- Cost effectiveness , Water conservation projects -- South Africa -- Southern Cape -- Cost effectiveness , Land use -- Economic aspects -- South Africa -- Eastern Cape , Land use -- Economic aspects -- South Africa -- Southern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10991 , http://hdl.handle.net/10948/340 , Water resources development -- South Africa -- Eastern Cape -- Cost effectiveness , Water resources development -- South Africa -- Southern Cape -- Cost effectiveness , Water conservation projects -- South Africa -- Eastern Cape -- Cost effectiveness , Water conservation projects -- South Africa -- Southern Cape -- Cost effectiveness , Land use -- Economic aspects -- South Africa -- Eastern Cape , Land use -- Economic aspects -- South Africa -- Southern Cape
- Description: 1.1 Background to, and motivation for, the study: The Working for Water programme (WfW) is a public works programme designed to clear South Africa of water-consuming invasive alien tree and plants, and to replace them with low water consuming indigenous species. This would prevent a loss of more than 4000 million cubic metres water per annum from the hydrological cycle (DWAF, 1998). The economic viability of the programme has been established in the Western Cape and Kwazulu-Natal (van Wilgen, Little, Chapman, Görgens, Willems and Marais, 1997; Gilham and Haynes, 2001), but questioned in the Eastern and Southern Cape (Hosking, du Preez, Campbell, Wooldridge and du Plessis, 2002). Hosking et al. (2002) investigated the economic case for the programme by performing a Cost Benefit Analysis (CBA), based on increased water yield and livestock potential, on six selected sites in the Eastern and Southern Cape, viz. Albany, Kat River, Pot River, Tsitsikamma, Kouga and Port Elizabeth Driftsands.
- Full Text:
- Date Issued: 2003
An evaluation of paired comparison models
- Venter, Daniel Jacobus Lodewyk
- Authors: Venter, Daniel Jacobus Lodewyk
- Date: 2004
- Subjects: Paired comparisons (Statistics) , Mathematical statistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11087 , http://hdl.handle.net/10948/364 , Paired comparisons (Statistics) , Mathematical statistics
- Description: Introduction: A typical task in quantitative data analysis is to derive estimates of population parameters based on sample statistics. For manifest variables this is usually a straightforward process utilising suitable measurement instruments and standard statistics such the mean, median and standard deviation. Latent variables on the other hand are typically more elusive, making it difficult to obtain valid and reliable measurements. One of the most widely used methods of estimating the parameter value of a latent variable is to use a summated score derived from a set of individual scores for each of the various attributes of the latent variable. A serious limitation of this method and other similar methods is that the validity and reliability of measurements depend on whether the statements included in the questionnaire cover all characteristics of the variable being measured and also on respondents’ ability to correctly indicate their perceived assessment of the characteristics on the scale provided. Methods without this limitation and that are especially useful where a set of objects/entities must be ranked based on the parameter values of one or more latent variables, are methods of paired comparisons. Although the underlying assumptions and algorithms of these methods often differ dramatically, they all rely on data derived from a series of comparisons, each consisting of a pair of specimens selected from the set of objects/entities being investigated. Typical examples of the comparison process are: subjects (judges) who have to indicate for each pair of objects which of the two they prefer; sport teams that compete against each other in matches that involve two teams at a time. The resultant data of each comparison range from a simple dichotomy to indicate which of the two objects are preferred/better, to an interval or ratio scale score for e d Bradley-Terry models, and were based on statistical theory assuming that the variable(s) being measured is either normally (Thurstone-Mosteller) or exponentially (Bradley-Terry) distributed. For many years researchers had to rely on these PCM’s when analysing paired comparison data without any idea about the implications if the distribution of the data from which their sample were obtained differed from the assumed distribution for the applicable PCM being utilised. To address this problem, PCM’s were subsequently developed to cater for discrete variables and variables with distributions that are neither normal or exponential. A question that remained unanswered is how the performance, as measured by the accuracy of parameter estimates, of PCM's are affected if they are applied to data from a range of discrete and continuous distribution that violates the assumptions on which the applicable paired comparison algorithm is based. This study is an attempt to answer this question by applying the most popular PCM's to a range of randomly derived data sets that spans typical continuous and discrete data distributions. It is hoped that the results of this study will assist researchers when selecting the most appropriate PCM to obtain accurate estimates of the parameters of the variables in their data sets.
- Full Text:
- Date Issued: 2004
- Authors: Venter, Daniel Jacobus Lodewyk
- Date: 2004
- Subjects: Paired comparisons (Statistics) , Mathematical statistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11087 , http://hdl.handle.net/10948/364 , Paired comparisons (Statistics) , Mathematical statistics
- Description: Introduction: A typical task in quantitative data analysis is to derive estimates of population parameters based on sample statistics. For manifest variables this is usually a straightforward process utilising suitable measurement instruments and standard statistics such the mean, median and standard deviation. Latent variables on the other hand are typically more elusive, making it difficult to obtain valid and reliable measurements. One of the most widely used methods of estimating the parameter value of a latent variable is to use a summated score derived from a set of individual scores for each of the various attributes of the latent variable. A serious limitation of this method and other similar methods is that the validity and reliability of measurements depend on whether the statements included in the questionnaire cover all characteristics of the variable being measured and also on respondents’ ability to correctly indicate their perceived assessment of the characteristics on the scale provided. Methods without this limitation and that are especially useful where a set of objects/entities must be ranked based on the parameter values of one or more latent variables, are methods of paired comparisons. Although the underlying assumptions and algorithms of these methods often differ dramatically, they all rely on data derived from a series of comparisons, each consisting of a pair of specimens selected from the set of objects/entities being investigated. Typical examples of the comparison process are: subjects (judges) who have to indicate for each pair of objects which of the two they prefer; sport teams that compete against each other in matches that involve two teams at a time. The resultant data of each comparison range from a simple dichotomy to indicate which of the two objects are preferred/better, to an interval or ratio scale score for e d Bradley-Terry models, and were based on statistical theory assuming that the variable(s) being measured is either normally (Thurstone-Mosteller) or exponentially (Bradley-Terry) distributed. For many years researchers had to rely on these PCM’s when analysing paired comparison data without any idea about the implications if the distribution of the data from which their sample were obtained differed from the assumed distribution for the applicable PCM being utilised. To address this problem, PCM’s were subsequently developed to cater for discrete variables and variables with distributions that are neither normal or exponential. A question that remained unanswered is how the performance, as measured by the accuracy of parameter estimates, of PCM's are affected if they are applied to data from a range of discrete and continuous distribution that violates the assumptions on which the applicable paired comparison algorithm is based. This study is an attempt to answer this question by applying the most popular PCM's to a range of randomly derived data sets that spans typical continuous and discrete data distributions. It is hoped that the results of this study will assist researchers when selecting the most appropriate PCM to obtain accurate estimates of the parameters of the variables in their data sets.
- Full Text:
- Date Issued: 2004
An evaluation of the Xenopus laevis liver slice model to study the toxic effects of microcystin
- Authors: Coates, Nadya
- Date: 2003
- Subjects: Zenopus laevis , Microcystis aeruginosa -- Toxicology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11069 , http://hdl.handle.net/10948/307 , Zenopus laevis , Microcystis aeruginosa -- Toxicology
- Description: Blooms of cyanobacteria have increased in occurrence in the past three decades and have been reported to cause severe problems for animals and humans, leading to death in extreme instances. The majority of poisonings that have taken place have been attributed to a hepatotoxin produced by the species Microcystis aeruginosa, namely microcystin. The appearance of a cyanobacterial bloom does not give any indication as to its toxicity and therefore, it is imperative that simple, yet sensitive, bioassays are developed to overcome this problem. This study was undertaken to evaluate the effects of microcystin-LR on the liver of Xenopus laevis both in vitro and in vivo. This animal provides an opportunity to study the long-term hepatotoxic effects of the toxin compared to in vitro studies performed with mice and rats. The use of the liver slice model system as a potential bioassay to study the effects of microcystin-LR on Xenopus laevis liver was evaluated. Liver slices were cultured in RPMI- 1640 culture medium for periods ranging from 30 hours to 10 days and the liver slices were exposed to toxin concentrations ranging from 1nM to 500nM. The use of frog liver slices to study the longer-term effects of low-dose exposure to microcystin-LR was evaluated by observing the ultrastructural changes within hepatocytes using transmission electron microscopy, the release of the enzymes alanine aminotransferase and lactate dehydrogenase into the surrounding culture medium, as well as using a 3-[4,5-dimethylthiazol-2yl]-2,5- diphenyl tetrazolium bromide assay to determine the viability of the liver slices in culture. The amount of lipid peroxidation in the liver slices after exposure to microcystin-LR was assessed using the Thiobarbituric Acid Test. Results showed the frog liver slice culture system to be an inadequate method to evaluate the hepatotoxic effects of microcystin-LR. An in vivo assessment of the effects of microcystin-LR on Xenopus laevis was carried out using a total of 9 frogs (3 groups of 3 frogs). Frogs received a single intraperitoneal dose of 120mg/kg of microcystin-LR and were sacrificed at 8 and 24 hours post exposure. Microcystin-LR caused no significant change in serum lactate dehydrogenase levels, hepatosomatic index (liver weight as a percentage body weight), glutathione peroxidase activity, glycogen or lipid peroxidation. There was, however, an increase in glutathione sii transferase activity in the liver. The presence of the toxin in the liver was confirmed by immunohistochemistry. This study suggests that Xenopus laevis has, in some way, adapted to detoxifying aquatic toxins in the environment.
- Full Text:
- Date Issued: 2003
- Authors: Coates, Nadya
- Date: 2003
- Subjects: Zenopus laevis , Microcystis aeruginosa -- Toxicology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11069 , http://hdl.handle.net/10948/307 , Zenopus laevis , Microcystis aeruginosa -- Toxicology
- Description: Blooms of cyanobacteria have increased in occurrence in the past three decades and have been reported to cause severe problems for animals and humans, leading to death in extreme instances. The majority of poisonings that have taken place have been attributed to a hepatotoxin produced by the species Microcystis aeruginosa, namely microcystin. The appearance of a cyanobacterial bloom does not give any indication as to its toxicity and therefore, it is imperative that simple, yet sensitive, bioassays are developed to overcome this problem. This study was undertaken to evaluate the effects of microcystin-LR on the liver of Xenopus laevis both in vitro and in vivo. This animal provides an opportunity to study the long-term hepatotoxic effects of the toxin compared to in vitro studies performed with mice and rats. The use of the liver slice model system as a potential bioassay to study the effects of microcystin-LR on Xenopus laevis liver was evaluated. Liver slices were cultured in RPMI- 1640 culture medium for periods ranging from 30 hours to 10 days and the liver slices were exposed to toxin concentrations ranging from 1nM to 500nM. The use of frog liver slices to study the longer-term effects of low-dose exposure to microcystin-LR was evaluated by observing the ultrastructural changes within hepatocytes using transmission electron microscopy, the release of the enzymes alanine aminotransferase and lactate dehydrogenase into the surrounding culture medium, as well as using a 3-[4,5-dimethylthiazol-2yl]-2,5- diphenyl tetrazolium bromide assay to determine the viability of the liver slices in culture. The amount of lipid peroxidation in the liver slices after exposure to microcystin-LR was assessed using the Thiobarbituric Acid Test. Results showed the frog liver slice culture system to be an inadequate method to evaluate the hepatotoxic effects of microcystin-LR. An in vivo assessment of the effects of microcystin-LR on Xenopus laevis was carried out using a total of 9 frogs (3 groups of 3 frogs). Frogs received a single intraperitoneal dose of 120mg/kg of microcystin-LR and were sacrificed at 8 and 24 hours post exposure. Microcystin-LR caused no significant change in serum lactate dehydrogenase levels, hepatosomatic index (liver weight as a percentage body weight), glutathione peroxidase activity, glycogen or lipid peroxidation. There was, however, an increase in glutathione sii transferase activity in the liver. The presence of the toxin in the liver was confirmed by immunohistochemistry. This study suggests that Xenopus laevis has, in some way, adapted to detoxifying aquatic toxins in the environment.
- Full Text:
- Date Issued: 2003
An exploration into the reasons for the resignation of ex-employees from the University of Port Elizabeth against international indicators in employee retention
- Authors: Anderson, Amber Cristal
- Date: 2003
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11000 , http://hdl.handle.net/10948/289
- Description: South African organisations have not been left untouched by the impact of globalisation on their business practices. In a bid to maintain and improve on their competitive advantage, they have had to embark on initiatives to secure a place in the global economy. Entwined herein is the challenge to embrace a whole new definition of equality and develop their human capital as described in various legislative interventions of the South African Government. This study reflects the outcomes of an exploratory study into the reasons for the resignation of ex-employees from the University of Port Elizabeth, against international indicators in employee retention. The research was based on the premise that an effective and efficient transformation strategy should originate from a tangible understanding of all the socio-behavioural and influencing aspects of employee retention. The results suggest the development of an employee-retention strategy which could facilitate the realisation of the Employment Equity Plan. The objectives of the study were: to provide critical insight into why employees are resigning from the University of Port Elizabeth (UPE), to determine the social and developmental expectations of ex-UPE employees while in a transforming organisation, to identify and analyse ex-employees’ perceptions of the implementation of UPE’s Employment Equity Plan, to analyse ex-employees’ perceptions of existing retention practices at UPE, to provide recommendations towards an employee-retention strategy for UPE. The study is exploratory and descriptive in nature, and is quantitatively analysed with limited qualitative inferences. The population consisted of ex-UPE employees who had left the service of the university, from 01 January 2000 to 31 October 2002, by resignation. The period coincided with the implementation phase of the UPE Employment Equity Plan. For the purpose of this study, N=69. Twenty-eight ex-employees were untraceable, therefore n=41. Thirty ex-employees took part in the survey, thus making the sample return 73%. Eight of the respondents were dispersed across three continents other than Africa. The survey instrument, administered as an e-mailed and mailed questionnaire, was selected as the most suitable quantitative research method, because respondents were globally dispersed. Content analysis was selected as the most appropriate technique to produce findings in the qualitative aspect of the research. Where appropriate, descriptive statistics (univariate and bivariate analyses) were applied to describe the variables, the results of which were exhibited as tabular or graphical displays. Inferential statistical analyses (Pearson Chi-square and M-L Chisquare tests) were also conducted.
- Full Text:
- Date Issued: 2003
- Authors: Anderson, Amber Cristal
- Date: 2003
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11000 , http://hdl.handle.net/10948/289
- Description: South African organisations have not been left untouched by the impact of globalisation on their business practices. In a bid to maintain and improve on their competitive advantage, they have had to embark on initiatives to secure a place in the global economy. Entwined herein is the challenge to embrace a whole new definition of equality and develop their human capital as described in various legislative interventions of the South African Government. This study reflects the outcomes of an exploratory study into the reasons for the resignation of ex-employees from the University of Port Elizabeth, against international indicators in employee retention. The research was based on the premise that an effective and efficient transformation strategy should originate from a tangible understanding of all the socio-behavioural and influencing aspects of employee retention. The results suggest the development of an employee-retention strategy which could facilitate the realisation of the Employment Equity Plan. The objectives of the study were: to provide critical insight into why employees are resigning from the University of Port Elizabeth (UPE), to determine the social and developmental expectations of ex-UPE employees while in a transforming organisation, to identify and analyse ex-employees’ perceptions of the implementation of UPE’s Employment Equity Plan, to analyse ex-employees’ perceptions of existing retention practices at UPE, to provide recommendations towards an employee-retention strategy for UPE. The study is exploratory and descriptive in nature, and is quantitatively analysed with limited qualitative inferences. The population consisted of ex-UPE employees who had left the service of the university, from 01 January 2000 to 31 October 2002, by resignation. The period coincided with the implementation phase of the UPE Employment Equity Plan. For the purpose of this study, N=69. Twenty-eight ex-employees were untraceable, therefore n=41. Thirty ex-employees took part in the survey, thus making the sample return 73%. Eight of the respondents were dispersed across three continents other than Africa. The survey instrument, administered as an e-mailed and mailed questionnaire, was selected as the most suitable quantitative research method, because respondents were globally dispersed. Content analysis was selected as the most appropriate technique to produce findings in the qualitative aspect of the research. Where appropriate, descriptive statistics (univariate and bivariate analyses) were applied to describe the variables, the results of which were exhibited as tabular or graphical displays. Inferential statistical analyses (Pearson Chi-square and M-L Chisquare tests) were also conducted.
- Full Text:
- Date Issued: 2003