Synthesis and pharmacological evaluation of chlorin derivatives for photodynamic therapy of cholangiocarcinoma
- Gao, Ying-Hua, Li, Man-Yi, Saijad, Faiza, Wang, Jin-Hai, Meharban, Faiza, Gadoora, Malaz A, Yan, Yi-Jia, Nyokong, Tebello, Chen, Zhi-Long
- Authors: Gao, Ying-Hua , Li, Man-Yi , Saijad, Faiza , Wang, Jin-Hai , Meharban, Faiza , Gadoora, Malaz A , Yan, Yi-Jia , Nyokong, Tebello , Chen, Zhi-Long
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190873 , vital:45036 , xlink:href="https://doi.org/10.1016/j.ejmech.2020.112049"
- Description: Photodynamic therapy (PDT) has been developed as a promising therapeutic method in cancer treatment. The discovery of effective photosensitizer, which is the key factor of PDT, is highly desired. This paper reports the synthesis of novel chlorin derivatives, 5,10,15,20-tetraphenyl-[2:3]-[(methoxycarbonyl, carboxy)methano] chlorin I and 5,10,15,20-tetraphenyl-[2:3]- {[methoxycarbonyl, (2-hydroxyethyl)amide]methano}chlorin II. Their structures were characterized with UV–vis, 1HNMR, 13CNMR and HRMS spectroscopies. Photophysical and photochemical experiments results showed that compound I and II had an absorption maximum around 650 nm, with molar extinction coefficients of 1 × 104 M−1 cm−1. They had strong fluorescence emission in 650–660 nm upon excitation with 419–422 nm light. ESR showed that singlet oxygen was produced upon irradiation of compounds with 650 nm light in the presence of molecular oxygen. The photo-bleaching test indicated that the structure of compounds was stable. These new compounds exhibit excellent anti-tumor effects and lower toxicity compared to m-THPC in vitro and in vivo. Compound I and II had high tumor selectivity, which could induced tumor cells shrinkage and necrosis under 650 nm laser irradiation. Flow cytometry revealed that the compounds might mediate PDT effect at late apoptotic phase. These results make these compound I and II promising candidates for future study in photo-diagnosis and photodynamic therapy of cholangiocarcinoma.
- Full Text:
- Date Issued: 2020
- Authors: Gao, Ying-Hua , Li, Man-Yi , Saijad, Faiza , Wang, Jin-Hai , Meharban, Faiza , Gadoora, Malaz A , Yan, Yi-Jia , Nyokong, Tebello , Chen, Zhi-Long
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190873 , vital:45036 , xlink:href="https://doi.org/10.1016/j.ejmech.2020.112049"
- Description: Photodynamic therapy (PDT) has been developed as a promising therapeutic method in cancer treatment. The discovery of effective photosensitizer, which is the key factor of PDT, is highly desired. This paper reports the synthesis of novel chlorin derivatives, 5,10,15,20-tetraphenyl-[2:3]-[(methoxycarbonyl, carboxy)methano] chlorin I and 5,10,15,20-tetraphenyl-[2:3]- {[methoxycarbonyl, (2-hydroxyethyl)amide]methano}chlorin II. Their structures were characterized with UV–vis, 1HNMR, 13CNMR and HRMS spectroscopies. Photophysical and photochemical experiments results showed that compound I and II had an absorption maximum around 650 nm, with molar extinction coefficients of 1 × 104 M−1 cm−1. They had strong fluorescence emission in 650–660 nm upon excitation with 419–422 nm light. ESR showed that singlet oxygen was produced upon irradiation of compounds with 650 nm light in the presence of molecular oxygen. The photo-bleaching test indicated that the structure of compounds was stable. These new compounds exhibit excellent anti-tumor effects and lower toxicity compared to m-THPC in vitro and in vivo. Compound I and II had high tumor selectivity, which could induced tumor cells shrinkage and necrosis under 650 nm laser irradiation. Flow cytometry revealed that the compounds might mediate PDT effect at late apoptotic phase. These results make these compound I and II promising candidates for future study in photo-diagnosis and photodynamic therapy of cholangiocarcinoma.
- Full Text:
- Date Issued: 2020
Best simultaneous approximation in normed linear spaces
- Authors: Johnson, Solomon Nathan
- Date: 2018
- Subjects: Normed linear spaces , Approximation theory , Mathematical analysis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/58985 , vital:27400
- Description: In this thesis we consider the problem of simultaneously approximating elements of a set B C X by a single element of a set K C X. This type of a problem arises when the element to be approximated is not known precisely but is known to belong to a set.Thus, best simultaneous approximation is a natural generalization of best approximation which has been studied extensively. The theory of best simultaneous approximation has been studied by many authors, see for example [4], [8], [25], [28], [26] and [12] to name but a few.
- Full Text:
- Date Issued: 2018
- Authors: Johnson, Solomon Nathan
- Date: 2018
- Subjects: Normed linear spaces , Approximation theory , Mathematical analysis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/58985 , vital:27400
- Description: In this thesis we consider the problem of simultaneously approximating elements of a set B C X by a single element of a set K C X. This type of a problem arises when the element to be approximated is not known precisely but is known to belong to a set.Thus, best simultaneous approximation is a natural generalization of best approximation which has been studied extensively. The theory of best simultaneous approximation has been studied by many authors, see for example [4], [8], [25], [28], [26] and [12] to name but a few.
- Full Text:
- Date Issued: 2018
An exposition of Hilbert C-modules
- Authors: Sokopo, Bulelani Joab
- Date: 2015
- Subjects: Mathematics Algebra , Functions, Continuous Mathematical analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/50008 , vital:41974
- Description: In trying to prove that derivations of type I AW -algebras are inner, I. Kaplansky introduced and developed the basics of the concept of Hilbert C- modules. He sought to generalize the idea of a Hilbert space by replacing the field C of all complex numbers with a general (commutative and unital) C-algebra. Twenty years later, the concept was broadened and expanded to non-commutative C-algebras by W. L. Paschke and M. A. Rieffel in their papers on inner product modules over B-algebras and induced representations of C-algebras, respectively. Since then, the theory of Hilbert C-modules has grown rapidly. It was used by G. G. Kasparov as the framework for his bivariant K-theory. More recently, Hilbert C-modules have formed the technical basis for the C*-algebraic approach to quantum group theory. The aim of this dissertation is to provide as detailed an account as possible of the theory of Hilbert C-modules, as given in a book of E. C. Lance, up to and including the KSGNS construction. The KSGNS construction, named after Kasparov, Stinespring, Gelfand, Naimark and Segal, is a generalization to Hilbert C-modules of the familiar GNS construction for C-algebras. The result by Kaplansky that all derivations of a type I AW-algebra are inner is given as an application in the final chapter of the dissertation.
- Full Text:
- Date Issued: 2015
- Authors: Sokopo, Bulelani Joab
- Date: 2015
- Subjects: Mathematics Algebra , Functions, Continuous Mathematical analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/50008 , vital:41974
- Description: In trying to prove that derivations of type I AW -algebras are inner, I. Kaplansky introduced and developed the basics of the concept of Hilbert C- modules. He sought to generalize the idea of a Hilbert space by replacing the field C of all complex numbers with a general (commutative and unital) C-algebra. Twenty years later, the concept was broadened and expanded to non-commutative C-algebras by W. L. Paschke and M. A. Rieffel in their papers on inner product modules over B-algebras and induced representations of C-algebras, respectively. Since then, the theory of Hilbert C-modules has grown rapidly. It was used by G. G. Kasparov as the framework for his bivariant K-theory. More recently, Hilbert C-modules have formed the technical basis for the C*-algebraic approach to quantum group theory. The aim of this dissertation is to provide as detailed an account as possible of the theory of Hilbert C-modules, as given in a book of E. C. Lance, up to and including the KSGNS construction. The KSGNS construction, named after Kasparov, Stinespring, Gelfand, Naimark and Segal, is a generalization to Hilbert C-modules of the familiar GNS construction for C-algebras. The result by Kaplansky that all derivations of a type I AW-algebra are inner is given as an application in the final chapter of the dissertation.
- Full Text:
- Date Issued: 2015
A modelling approach to the analysis of complex survey data
- Authors: Dlangamandla, Olwethu
- Date: 2021-10-29
- Subjects: Sampling (Statistics) , Linear models (Statistics) , Multilevel models (Statistics) , Logistic regression analysis , Complex survey data
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192955 , vital:45284
- Description: Surveys are an essential tool for collecting data and most surveys use complex sampling designs to collect the data. Complex sampling designs are used mainly to enhance representativeness in the sample by accounting for the underlying structure of the population. This often results in data that are non-independent and clustered. Ignoring complex design features such as clustering, stratification, multistage and unequal probability sampling may result in inaccurate and incorrect inference. An overview of, and difference between, design-based and model-based approaches to inference for complex survey data has been discussed. This study adopts a model-based approach. The objective of this study is to discuss and describe the modelling approach in analysing complex survey data. This is specifically done by introducing the principle inference methods under which data from complex surveys may be analysed. In particular, discussions on the theory and methods of model fitting for the analysis of complex survey data are presented. We begin by discussing unique features of complex survey data and explore appropriate methods of analysis that account for the complexity inherent in the survey data. We also explore the widely applied logistic regression modelling of binary data in a complex sample survey context. In particular, four forms of logistic regression models are fitted. These models are generalized linear models, multilevel models, mixed effects models and generalized linear mixed models. Simulated complex survey data are used to illustrate the methods and models. Various R packages are used for the analysis. The results presented and discussed in this thesis indicate that a logistic mixed model with first and second level predictors has a better fit compared to a logistic mixed model with first level predictors. In addition, a logistic multilevel model with first and second level predictors and nested random effects provides a better fit to the data compared to other logistic multilevel fitted models. Similar results were obtained from fitting a generalized logistic mixed model with first and second level predictor variables and a generalized linear mixed model with first and second level predictors and nested random effects. , Thesis (MSC) -- Faculty of Science, Statistics, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Dlangamandla, Olwethu
- Date: 2021-10-29
- Subjects: Sampling (Statistics) , Linear models (Statistics) , Multilevel models (Statistics) , Logistic regression analysis , Complex survey data
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192955 , vital:45284
- Description: Surveys are an essential tool for collecting data and most surveys use complex sampling designs to collect the data. Complex sampling designs are used mainly to enhance representativeness in the sample by accounting for the underlying structure of the population. This often results in data that are non-independent and clustered. Ignoring complex design features such as clustering, stratification, multistage and unequal probability sampling may result in inaccurate and incorrect inference. An overview of, and difference between, design-based and model-based approaches to inference for complex survey data has been discussed. This study adopts a model-based approach. The objective of this study is to discuss and describe the modelling approach in analysing complex survey data. This is specifically done by introducing the principle inference methods under which data from complex surveys may be analysed. In particular, discussions on the theory and methods of model fitting for the analysis of complex survey data are presented. We begin by discussing unique features of complex survey data and explore appropriate methods of analysis that account for the complexity inherent in the survey data. We also explore the widely applied logistic regression modelling of binary data in a complex sample survey context. In particular, four forms of logistic regression models are fitted. These models are generalized linear models, multilevel models, mixed effects models and generalized linear mixed models. Simulated complex survey data are used to illustrate the methods and models. Various R packages are used for the analysis. The results presented and discussed in this thesis indicate that a logistic mixed model with first and second level predictors has a better fit compared to a logistic mixed model with first level predictors. In addition, a logistic multilevel model with first and second level predictors and nested random effects provides a better fit to the data compared to other logistic multilevel fitted models. Similar results were obtained from fitting a generalized logistic mixed model with first and second level predictor variables and a generalized linear mixed model with first and second level predictors and nested random effects. , Thesis (MSC) -- Faculty of Science, Statistics, 2021
- Full Text:
- Date Issued: 2021-10-29
The economics of converting a sheep farm into a springbuck (Antidorcas marsupialis) ranch in Graaff-Reinet: a simulation analysis
- Authors: Dlamini, Thula Sizwe
- Date: 2012
- Subjects: Livestock projects -- South Africa -- Eastern Cape Livestock productivity -- South Africa -- Eastern Cape Livestock -- Economic aspects -- South Africa -- Eastern Cape Sheep -- Breeding -- South Africa -- Eastern Cape Springbok -- Breeding -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1003 , http://hdl.handle.net/10962/d1002738
- Description: In Graaff-Reinet, domestic livestock farming and springbuck ranching are similar in that they both rely on the rangeland for their sustainability. However, as a consequence of repeated monotonous domestic livestock farming, resulting in compromised biological productivity and diversity, the rangelands have disintegrated. This, unfortunately, has placed the future sustainability of these rangelands and the livelihoods of the local people in an indeterminate state. In recent years, there has been an increasing interest in springbuck ranching for meat production as an alternative to domestic livestock farming in the area following (a) fears of worsening environmental challenges; (b) declining profitability in commercial domestic livestock farming and; (c) growing calls for the sustainable use of these rangelands for the benefit of future generations. The springbuck has emerged as a credible alternative to utilising the rangelands - as opposed to sheep - because of its promise to addressing the above challenges. This is in an attempt to tap into the multitude of benefits that the springbuck possesses (by virtue of being part of the natural capital of the area) that have a potential towards restoring ecological integrity by extenuating some of the detrimental effects of sheep farming on the rangelands and presenting opportunities for diversifying incomes. Yet, despite the general increase in interest, a resistance towards the uptake of springbuck ranching for meat production exists. The main contention is that springbuck meat production cannot out-perform the economic returns of wool sheep farming. This study attempts to address these concerns by investigating the profitability and economic sustainability of converting a sheep farm into a springbuck ranch in Graaff-Reinet. The study uses stochastic simulation to estimate the probability distribution of some key output variables, namely: net cash income, ending cash balance, real net worth and the net present value (NPV) in evaluating the profitability of converting a 5 000ha sheep-dominated farm into a springbuck-dominated ranch under three alternative scenarios. The use of stochastic simulation allows for the incorporation of downside risk associated with the production and marketing of wool, mutton and springbuck meat. The study uses stochastic prices and yields to calculate net returns variability. Incorporating scenario analysis helped to evaluate how alternative wool sheep-dominated and springbuck-dominated combinations would perform based on the probable outcomes of different assumptions in the various scenarios. By applying stochastic efficiency with respect to a function (SERF) criterion to the simulated NPVs, this study compares the profitability of alternative scenarios based on various risk aversion coefficients. The study finds that converting a 5 000ha wool sheep dominated farm into a springbuck dominated ranch could potentially be a more profitable investment than wool sheep farming over a 15 year planning horizon, in Graaff-Reinet. The SERF results indicate that for all scenarios tested, the best strategy of converting a wool sheep dominated farm into a springbuck ranch would be one which comprise a combination of 70% springbuck, 20% mutton and 10% wool production as the likely profitable enterprise mix. Using economic sustainability analysis, the study reveals that because of low costs in springbuck ranching, springbuck meat production enterprises are most likely to be more financially sustainable than wool sheep-dominated enterprises. This suggests that rangeland owners may be better off converting their wool sheep-dominated farms into springbuck-dominated ranches. Thus, as the call for more environmentally benign rangeland utilising economic-ecological systems intensifies, rangeland owners in the Eastern Cape Karoo have a practicable option. At the very least, there exists an option to broaden their incomes whilst promoting ecological restoration with springbuck meat production.
- Full Text:
- Date Issued: 2012
- Authors: Dlamini, Thula Sizwe
- Date: 2012
- Subjects: Livestock projects -- South Africa -- Eastern Cape Livestock productivity -- South Africa -- Eastern Cape Livestock -- Economic aspects -- South Africa -- Eastern Cape Sheep -- Breeding -- South Africa -- Eastern Cape Springbok -- Breeding -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1003 , http://hdl.handle.net/10962/d1002738
- Description: In Graaff-Reinet, domestic livestock farming and springbuck ranching are similar in that they both rely on the rangeland for their sustainability. However, as a consequence of repeated monotonous domestic livestock farming, resulting in compromised biological productivity and diversity, the rangelands have disintegrated. This, unfortunately, has placed the future sustainability of these rangelands and the livelihoods of the local people in an indeterminate state. In recent years, there has been an increasing interest in springbuck ranching for meat production as an alternative to domestic livestock farming in the area following (a) fears of worsening environmental challenges; (b) declining profitability in commercial domestic livestock farming and; (c) growing calls for the sustainable use of these rangelands for the benefit of future generations. The springbuck has emerged as a credible alternative to utilising the rangelands - as opposed to sheep - because of its promise to addressing the above challenges. This is in an attempt to tap into the multitude of benefits that the springbuck possesses (by virtue of being part of the natural capital of the area) that have a potential towards restoring ecological integrity by extenuating some of the detrimental effects of sheep farming on the rangelands and presenting opportunities for diversifying incomes. Yet, despite the general increase in interest, a resistance towards the uptake of springbuck ranching for meat production exists. The main contention is that springbuck meat production cannot out-perform the economic returns of wool sheep farming. This study attempts to address these concerns by investigating the profitability and economic sustainability of converting a sheep farm into a springbuck ranch in Graaff-Reinet. The study uses stochastic simulation to estimate the probability distribution of some key output variables, namely: net cash income, ending cash balance, real net worth and the net present value (NPV) in evaluating the profitability of converting a 5 000ha sheep-dominated farm into a springbuck-dominated ranch under three alternative scenarios. The use of stochastic simulation allows for the incorporation of downside risk associated with the production and marketing of wool, mutton and springbuck meat. The study uses stochastic prices and yields to calculate net returns variability. Incorporating scenario analysis helped to evaluate how alternative wool sheep-dominated and springbuck-dominated combinations would perform based on the probable outcomes of different assumptions in the various scenarios. By applying stochastic efficiency with respect to a function (SERF) criterion to the simulated NPVs, this study compares the profitability of alternative scenarios based on various risk aversion coefficients. The study finds that converting a 5 000ha wool sheep dominated farm into a springbuck dominated ranch could potentially be a more profitable investment than wool sheep farming over a 15 year planning horizon, in Graaff-Reinet. The SERF results indicate that for all scenarios tested, the best strategy of converting a wool sheep dominated farm into a springbuck ranch would be one which comprise a combination of 70% springbuck, 20% mutton and 10% wool production as the likely profitable enterprise mix. Using economic sustainability analysis, the study reveals that because of low costs in springbuck ranching, springbuck meat production enterprises are most likely to be more financially sustainable than wool sheep-dominated enterprises. This suggests that rangeland owners may be better off converting their wool sheep-dominated farms into springbuck-dominated ranches. Thus, as the call for more environmentally benign rangeland utilising economic-ecological systems intensifies, rangeland owners in the Eastern Cape Karoo have a practicable option. At the very least, there exists an option to broaden their incomes whilst promoting ecological restoration with springbuck meat production.
- Full Text:
- Date Issued: 2012
Prediction of protein secondary structure using binary classificationtrees, naive Bayes classifiers and the Logistic Regression Classifier
- Eldud Omer, Ahmed Abdelkarim
- Authors: Eldud Omer, Ahmed Abdelkarim
- Date: 2016
- Subjects: Bayesian statistical decision theory , Logistic regression analysis , Biostatistics , Proteins -- Structure
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5581 , http://hdl.handle.net/10962/d1019985
- Description: The secondary structure of proteins is predicted using various binary classifiers. The data are adopted from the RS126 database. The original data consists of protein primary and secondary structure sequences. The original data is encoded using alphabetic letters. These data are encoded into unary vectors comprising ones and zeros only. Different binary classifiers, namely the naive Bayes, logistic regression and classification trees using hold-out and 5-fold cross validation are trained using the encoded data. For each of the classifiers three classification tasks are considered, namely helix against not helix (H/∼H), sheet against not sheet (S/∼S) and coil against not coil (C/∼C). The performance of these binary classifiers are compared using the overall accuracy in predicting the protein secondary structure for various window sizes. Our result indicate that hold-out cross validation achieved higher accuracy than 5-fold cross validation. The Naive Bayes classifier, using 5-fold cross validation achieved, the lowest accuracy for predicting helix against not helix. The classification tree classifiers, using 5-fold cross validation, achieved the lowest accuracies for both coil against not coil and sheet against not sheet classifications. The logistic regression classier accuracy is dependent on the window size; there is a positive relationship between the accuracy and window size. The logistic regression classier approach achieved the highest accuracy when compared to the classification tree and Naive Bayes classifiers for each classification task; predicting helix against not helix with accuracy 77.74 percent, for sheet against not sheet with accuracy 81.22 percent and for coil against not coil with accuracy 73.39 percent. It is noted that it is easier to compare classifiers if the classification process could be completely facilitated in R. Alternatively, it would be easier to assess these logistic regression classifiers if SPSS had a function to determine the accuracy of the logistic regression classifier.
- Full Text:
- Date Issued: 2016
- Authors: Eldud Omer, Ahmed Abdelkarim
- Date: 2016
- Subjects: Bayesian statistical decision theory , Logistic regression analysis , Biostatistics , Proteins -- Structure
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5581 , http://hdl.handle.net/10962/d1019985
- Description: The secondary structure of proteins is predicted using various binary classifiers. The data are adopted from the RS126 database. The original data consists of protein primary and secondary structure sequences. The original data is encoded using alphabetic letters. These data are encoded into unary vectors comprising ones and zeros only. Different binary classifiers, namely the naive Bayes, logistic regression and classification trees using hold-out and 5-fold cross validation are trained using the encoded data. For each of the classifiers three classification tasks are considered, namely helix against not helix (H/∼H), sheet against not sheet (S/∼S) and coil against not coil (C/∼C). The performance of these binary classifiers are compared using the overall accuracy in predicting the protein secondary structure for various window sizes. Our result indicate that hold-out cross validation achieved higher accuracy than 5-fold cross validation. The Naive Bayes classifier, using 5-fold cross validation achieved, the lowest accuracy for predicting helix against not helix. The classification tree classifiers, using 5-fold cross validation, achieved the lowest accuracies for both coil against not coil and sheet against not sheet classifications. The logistic regression classier accuracy is dependent on the window size; there is a positive relationship between the accuracy and window size. The logistic regression classier approach achieved the highest accuracy when compared to the classification tree and Naive Bayes classifiers for each classification task; predicting helix against not helix with accuracy 77.74 percent, for sheet against not sheet with accuracy 81.22 percent and for coil against not coil with accuracy 73.39 percent. It is noted that it is easier to compare classifiers if the classification process could be completely facilitated in R. Alternatively, it would be easier to assess these logistic regression classifiers if SPSS had a function to determine the accuracy of the logistic regression classifier.
- Full Text:
- Date Issued: 2016
Statistical and Mathematical Learning: an application to fraud detection and prevention
- Authors: Hamlomo, Sisipho
- Date: 2022-04-06
- Subjects: Credit card fraud , Bootstrap (Statistics) , Support vector machines , Neural networks (Computer science) , Decision trees , Machine learning , Cross-validation , Imbalanced data
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/233795 , vital:50128
- Description: Credit card fraud is an ever-growing problem. There has been a rapid increase in the rate of fraudulent activities in recent years resulting in a considerable loss to several organizations, companies, and government agencies. Many researchers have focused on detecting fraudulent behaviours early using advanced machine learning techniques. However, credit card fraud detection is not a straightforward task since fraudulent behaviours usually differ for each attempt and the dataset is highly imbalanced, that is, the frequency of non-fraudulent cases outnumbers the frequency of fraudulent cases. In the case of the European credit card dataset, we have a ratio of approximately one fraudulent case to five hundred and seventy-eight non-fraudulent cases. Different methods were implemented to overcome this problem, namely random undersampling, one-sided sampling, SMOTE combined with Tomek links and parameter tuning. Predictive classifiers, namely logistic regression, decision trees, k-nearest neighbour, support vector machine and multilayer perceptrons, are applied to predict if a transaction is fraudulent or non-fraudulent. The model's performance is evaluated based on recall, precision, F1-score, the area under receiver operating characteristics curve, geometric mean and Matthew correlation coefficient. The results showed that the logistic regression classifier performed better than other classifiers except when the dataset was oversampled. , Thesis (MSc) -- Faculty of Science, Statistics, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Hamlomo, Sisipho
- Date: 2022-04-06
- Subjects: Credit card fraud , Bootstrap (Statistics) , Support vector machines , Neural networks (Computer science) , Decision trees , Machine learning , Cross-validation , Imbalanced data
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/233795 , vital:50128
- Description: Credit card fraud is an ever-growing problem. There has been a rapid increase in the rate of fraudulent activities in recent years resulting in a considerable loss to several organizations, companies, and government agencies. Many researchers have focused on detecting fraudulent behaviours early using advanced machine learning techniques. However, credit card fraud detection is not a straightforward task since fraudulent behaviours usually differ for each attempt and the dataset is highly imbalanced, that is, the frequency of non-fraudulent cases outnumbers the frequency of fraudulent cases. In the case of the European credit card dataset, we have a ratio of approximately one fraudulent case to five hundred and seventy-eight non-fraudulent cases. Different methods were implemented to overcome this problem, namely random undersampling, one-sided sampling, SMOTE combined with Tomek links and parameter tuning. Predictive classifiers, namely logistic regression, decision trees, k-nearest neighbour, support vector machine and multilayer perceptrons, are applied to predict if a transaction is fraudulent or non-fraudulent. The model's performance is evaluated based on recall, precision, F1-score, the area under receiver operating characteristics curve, geometric mean and Matthew correlation coefficient. The results showed that the logistic regression classifier performed better than other classifiers except when the dataset was oversampled. , Thesis (MSc) -- Faculty of Science, Statistics, 2022
- Full Text:
- Date Issued: 2022-04-06
Novel cationic-chalcone phthalocyanines for photodynamic therapy eradication of S. aureus and E. coli bacterial biofilms and MCF-7 breast cancer
- Openda, Yolande Ikala, Babu, Balaji, Nyokong, Tebello
- Authors: Openda, Yolande Ikala , Babu, Balaji , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300129 , vital:57895 , xlink:href="https://doi.org/10.1016/j.pdpdt.2022.102863"
- Description: New tetrasubstituted zinc (II) and indium (III) phthalocyanines bearing dimethylamino chalcone group (complexes 3 and 4) as well as their quaternized analogs (3a and 4a) have been assessed for their photodynamic therapy (PDT) of cancer as well as photodynamic antimicrobial chemotherapy activities against biofilms and planktonic cultures of pathogenic bacteria of Staphylococcus aureus and Escherichia coli. Compared to the non-quaternized phthalocyanines 3 and 4, the cationic phthalocyanines 3a and 4a exhibit a higher photodynamic inactivation against the planktonic cells with log reduction values above 9 at a concentration of 1.25 µM. This was attributed to the positive charge which enhances cellular uptake. More interestingly, 3a and 4a show a higher photodynamic inactivation (less than 3% of S. aureus survived) on their biofilm counterparts thanks to their stronger affinity to these cells. 3a and 4a Pcs also exhibited interesting PDT activity against MCF-7 cancer cells giving IC50 values of 17.9 and 7.4 μM, respectively following 15 min irradiation. The obtained results in this work show that the positively charged phthalocyanines 3a and 4a are potential antibacterial photosensitizers that show some selectivity toward the Gram-positive and Gram-negative bacteria as well as MCF-7 breasts cancer cells.
- Full Text:
- Date Issued: 2022
- Authors: Openda, Yolande Ikala , Babu, Balaji , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300129 , vital:57895 , xlink:href="https://doi.org/10.1016/j.pdpdt.2022.102863"
- Description: New tetrasubstituted zinc (II) and indium (III) phthalocyanines bearing dimethylamino chalcone group (complexes 3 and 4) as well as their quaternized analogs (3a and 4a) have been assessed for their photodynamic therapy (PDT) of cancer as well as photodynamic antimicrobial chemotherapy activities against biofilms and planktonic cultures of pathogenic bacteria of Staphylococcus aureus and Escherichia coli. Compared to the non-quaternized phthalocyanines 3 and 4, the cationic phthalocyanines 3a and 4a exhibit a higher photodynamic inactivation against the planktonic cells with log reduction values above 9 at a concentration of 1.25 µM. This was attributed to the positive charge which enhances cellular uptake. More interestingly, 3a and 4a show a higher photodynamic inactivation (less than 3% of S. aureus survived) on their biofilm counterparts thanks to their stronger affinity to these cells. 3a and 4a Pcs also exhibited interesting PDT activity against MCF-7 cancer cells giving IC50 values of 17.9 and 7.4 μM, respectively following 15 min irradiation. The obtained results in this work show that the positively charged phthalocyanines 3a and 4a are potential antibacterial photosensitizers that show some selectivity toward the Gram-positive and Gram-negative bacteria as well as MCF-7 breasts cancer cells.
- Full Text:
- Date Issued: 2022
The energy transition patterns of low-income households in South Africa: an evaluation of energy programme and policy
- Israel-Akinbo, Sylvia O, Snowball, Jeanette D, Fraser, Gavin C G
- Authors: Israel-Akinbo, Sylvia O , Snowball, Jeanette D , Fraser, Gavin C G
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69397 , vital:29518 , https://doi.org/10.17159/2413-3051/2018/v29i3a3310
- Description: The transition to modern energy carriers like electricity is an important way to achieve to eradicate energy poverty. This study investigated energy transition patterns and trends in low-income South African households. The marginal effects of the different determinants on the probability of choosing a specific energy carrier were computed and the influence of some endogenous characteristics in transitioning to modern energy carriers was explored. It was found that energy ladder behaviour exists for cooking while energy stacking was most likely for space heating and the pattern for lighting tended towards energy stacking. Dwelling type, household size and geographical location were among the key determinants of the energy transition pattern. Policies to reduce energy poverty need a multi-pronged approach and not only a focus on electricity access.
- Full Text:
- Date Issued: 2018
- Authors: Israel-Akinbo, Sylvia O , Snowball, Jeanette D , Fraser, Gavin C G
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69397 , vital:29518 , https://doi.org/10.17159/2413-3051/2018/v29i3a3310
- Description: The transition to modern energy carriers like electricity is an important way to achieve to eradicate energy poverty. This study investigated energy transition patterns and trends in low-income South African households. The marginal effects of the different determinants on the probability of choosing a specific energy carrier were computed and the influence of some endogenous characteristics in transitioning to modern energy carriers was explored. It was found that energy ladder behaviour exists for cooking while energy stacking was most likely for space heating and the pattern for lighting tended towards energy stacking. Dwelling type, household size and geographical location were among the key determinants of the energy transition pattern. Policies to reduce energy poverty need a multi-pronged approach and not only a focus on electricity access.
- Full Text:
- Date Issued: 2018
Total Music Meeting '80
- Unknown
- Authors: Unknown
- Subjects: McGregor, Chris -- 1936-1990 , Blue Notes (Musical group : South Africa) , Pukwana, Dudu , Moholo, Louis T.--1940- , Dyani, Johnny Mbizo
- Language: German
- Type: Text
- Identifier: vital:13792 , http://hdl.handle.net/10962/d1012825
- Description: Original program for the Berlin's music festival "Total Music Meeting '80", in Germany.
- Full Text:
- Authors: Unknown
- Subjects: McGregor, Chris -- 1936-1990 , Blue Notes (Musical group : South Africa) , Pukwana, Dudu , Moholo, Louis T.--1940- , Dyani, Johnny Mbizo
- Language: German
- Type: Text
- Identifier: vital:13792 , http://hdl.handle.net/10962/d1012825
- Description: Original program for the Berlin's music festival "Total Music Meeting '80", in Germany.
- Full Text:
Newsletter of the Self-Employed Womens Union - No.22
- SEWU
- Authors: SEWU
- Date: 1997
- Subjects: SEWU
- Language: Afrikaans, Xhosa
- Type: text
- Identifier: http://hdl.handle.net/10962/155100 , vital:39855
- Description: Die Derde Jaarlikse Konferensie van SEWU sal vanaf 22 -24 Julie plaasvind. Dit is die eerste nasionale konferensie vandat SEWU buite die grense van KwaZulu- Natal begin organiseer het. Afgevaardigdes van die Wes-Kaap sal ook by hierdie Konferensie wees. SEWU lede sal afgevaardigdes uit hulle eie geledere kies om hulle by hierdie Konferensie te verteenwoordig. Daar is ongeveer 48 SEWU takke waarvan 15 in die KwaZulu-Natal se landelike gebiede is. Een afgevaardigde word vanuit elke 20 opbetaalde lede in ’n tak verkies. Ons verwag tussen 100 en 150 afgevaardigdes.
- Full Text:
- Date Issued: 1997
- Authors: SEWU
- Date: 1997
- Subjects: SEWU
- Language: Afrikaans, Xhosa
- Type: text
- Identifier: http://hdl.handle.net/10962/155100 , vital:39855
- Description: Die Derde Jaarlikse Konferensie van SEWU sal vanaf 22 -24 Julie plaasvind. Dit is die eerste nasionale konferensie vandat SEWU buite die grense van KwaZulu- Natal begin organiseer het. Afgevaardigdes van die Wes-Kaap sal ook by hierdie Konferensie wees. SEWU lede sal afgevaardigdes uit hulle eie geledere kies om hulle by hierdie Konferensie te verteenwoordig. Daar is ongeveer 48 SEWU takke waarvan 15 in die KwaZulu-Natal se landelike gebiede is. Een afgevaardigde word vanuit elke 20 opbetaalde lede in ’n tak verkies. Ons verwag tussen 100 en 150 afgevaardigdes.
- Full Text:
- Date Issued: 1997
Newsletter of the Self-Employed Womens Union - No.22
- SEWU
- Authors: SEWU
- Date: 1997
- Subjects: SEWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/155037 , vital:39835
- Description: Die Derde Jaarlikse Konferensie van SEWU sal vanaf 22 -24 Julie plaasvind. Dit is die eerste nasionale konferensie vandat SEWU buite die grense van KwaZulu- Natal begin organiseer het. Afgevaardigdes van die Wes-Kaap sal ook by hierdie Konferensie wees. EWU lede sal afgevaardigdes uit hulle eie geledere kies om hulle by hierdie Konferensie te verteenwoordig. Daar is ongeveer 48 SEWU takke waarvan 15 in die KwaZulu-Natal se landelike gebiede is. Een afgevaardigde word vanuit elke 20 opbetaalde lede in ’n tak verkies. Ons verwag tussen 100 en 150 afgevaardigdes.
- Full Text:
- Date Issued: 1997
- Authors: SEWU
- Date: 1997
- Subjects: SEWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/155037 , vital:39835
- Description: Die Derde Jaarlikse Konferensie van SEWU sal vanaf 22 -24 Julie plaasvind. Dit is die eerste nasionale konferensie vandat SEWU buite die grense van KwaZulu- Natal begin organiseer het. Afgevaardigdes van die Wes-Kaap sal ook by hierdie Konferensie wees. EWU lede sal afgevaardigdes uit hulle eie geledere kies om hulle by hierdie Konferensie te verteenwoordig. Daar is ongeveer 48 SEWU takke waarvan 15 in die KwaZulu-Natal se landelike gebiede is. Een afgevaardigde word vanuit elke 20 opbetaalde lede in ’n tak verkies. Ons verwag tussen 100 en 150 afgevaardigdes.
- Full Text:
- Date Issued: 1997
Generalized linear models, with applications in fisheries research
- Authors: Sidumo, Bonelwa
- Date: 2018
- Subjects: Western mosquitofish , Analysis of variance , Fisheries Catch effort South Africa Sundays River (Eastern Cape) , Linear models (Statistics) , Multilevel models (Statistics) , Experimental design
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/61102 , vital:27975
- Description: Gambusia affinis (G. affinis) is an invasive fish species found in the Sundays River Valley of the Eastern Cape, South Africa, The relative abundance and population dynamics of G. affinis were quantified in five interconnected impoundments within the Sundays River Valley, This study utilised a G. affinis data set to demonstrate various, classical ANOVA models. Generalized linear models were used to standardize catch per unit effort (CPUE) estimates and to determine environmental variables which influenced the CPUE, Based on the generalized linear model results dam age, mean temperature, Oreochromis mossambicus abundance and Glossogobius callidus abundance had a significant effect on the G. affinis CPUE. The Albany Angling Association collected data during fishing tag and release events. These data were utilized to demonstrate repeated measures designs. Mixed-effects models provided a powerful and flexible tool for analyzing clustered data such as repeated measures data and nested data, lienee it has become tremendously popular as a framework for the analysis of bio-behavioral experiments. The results show that the mixed-effects methods proposed in this study are more efficient than those based on generalized linear models. These data were better modeled with mixed-effects models due to their flexibility in handling missing data.
- Full Text:
- Date Issued: 2018
- Authors: Sidumo, Bonelwa
- Date: 2018
- Subjects: Western mosquitofish , Analysis of variance , Fisheries Catch effort South Africa Sundays River (Eastern Cape) , Linear models (Statistics) , Multilevel models (Statistics) , Experimental design
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/61102 , vital:27975
- Description: Gambusia affinis (G. affinis) is an invasive fish species found in the Sundays River Valley of the Eastern Cape, South Africa, The relative abundance and population dynamics of G. affinis were quantified in five interconnected impoundments within the Sundays River Valley, This study utilised a G. affinis data set to demonstrate various, classical ANOVA models. Generalized linear models were used to standardize catch per unit effort (CPUE) estimates and to determine environmental variables which influenced the CPUE, Based on the generalized linear model results dam age, mean temperature, Oreochromis mossambicus abundance and Glossogobius callidus abundance had a significant effect on the G. affinis CPUE. The Albany Angling Association collected data during fishing tag and release events. These data were utilized to demonstrate repeated measures designs. Mixed-effects models provided a powerful and flexible tool for analyzing clustered data such as repeated measures data and nested data, lienee it has become tremendously popular as a framework for the analysis of bio-behavioral experiments. The results show that the mixed-effects methods proposed in this study are more efficient than those based on generalized linear models. These data were better modeled with mixed-effects models due to their flexibility in handling missing data.
- Full Text:
- Date Issued: 2018
The importance of demographic trends in forecasting energy demand for private households in South africa
- Authors: Thubeni,Sinethemba Morine
- Date: 2015
- Subjects: Electric power consumption -- South Africa -- Forecasting Households -- South Africa , Demography -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45322 , vital:38570
- Description: South Africa’s residential energy use is expected to grow at approximately the same rate as the population. Efficient planning for energy demand by energy suppliers is therefore, essential since shortage of energy will negatively affect economic growth.This paper aims to investigate the causal relationship between population and house-hold energy demand on coal, gas, paraffin and wood for private households in South Africa. The adjusted R2, AIC (Akaike information criterion), the BIC (Bayesian information criterion) and standard deviation of residuals were used to investigate which model is the best to predict energy demand in each province using all available information. The results show that population and household energy demand are associated with each other. The findings imply that the causality between population growth and household energy demand is bidirectional in most cases.
- Full Text:
- Date Issued: 2015
- Authors: Thubeni,Sinethemba Morine
- Date: 2015
- Subjects: Electric power consumption -- South Africa -- Forecasting Households -- South Africa , Demography -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45322 , vital:38570
- Description: South Africa’s residential energy use is expected to grow at approximately the same rate as the population. Efficient planning for energy demand by energy suppliers is therefore, essential since shortage of energy will negatively affect economic growth.This paper aims to investigate the causal relationship between population and house-hold energy demand on coal, gas, paraffin and wood for private households in South Africa. The adjusted R2, AIC (Akaike information criterion), the BIC (Bayesian information criterion) and standard deviation of residuals were used to investigate which model is the best to predict energy demand in each province using all available information. The results show that population and household energy demand are associated with each other. The findings imply that the causality between population growth and household energy demand is bidirectional in most cases.
- Full Text:
- Date Issued: 2015
Abasebenzi bempahla manyanani
- Authors: Labour History Group
- Date: 1983-08
- Subjects: Uncatalogued
- Language: Xhosa
- Type: text , book
- Identifier: http://hdl.handle.net/10962/299946 , vital:57874
- Description: Abantu abamnyama bahlupheka ngakumbi ngokuye kusanda kobungxowankulu emZantsi Afrika. Abamhlophe abaninzi bazuze kobubungxowa nkulu. Abamhlophe babanolawulo kwinkompani zemiGodi; belawula nefaraa ezinkulu kwanamizi Mvaliso ngo- kunjalo. Abasebenzi abamhlophe emigodini ba- sebenzisa uMona ukuzuza ngokuphindwe kalishumi kunabamnyama.Kodwa ayingabobonke abamhlophe ababanelo- thamsanqa. Abanye abamhlophe babehluphekule. Belahlekana nemihlaba yabo ngokungxothwa ngo- nofama abatyebileyo. Baya ezidolophini apho bahlala ngokuhlwempuzeka okukhulu njengabobonke abamnyama. Uninzi 1walamahlwempu amhlophe yayi- ngamaBulu.Lamahlwempu amaBulu ayengafundanga engenayo na- nqeqesho ngezoshishino bafumana kunzima uku- fumana imisebenzi. Babanokwenza umsebenzi aba- ngawuqeqeshelwanga kodwa abaqeshi babewunika abemnyama bona babehlawula phantsi. uRulumente wancedisana neqaqobana lalamahlwempu amhlophe angena ngqeqesho ngokuwafunela umsebenzi kwa- Loliwe.
- Full Text:
- Date Issued: 1983-08
- Authors: Labour History Group
- Date: 1983-08
- Subjects: Uncatalogued
- Language: Xhosa
- Type: text , book
- Identifier: http://hdl.handle.net/10962/299946 , vital:57874
- Description: Abantu abamnyama bahlupheka ngakumbi ngokuye kusanda kobungxowankulu emZantsi Afrika. Abamhlophe abaninzi bazuze kobubungxowa nkulu. Abamhlophe babanolawulo kwinkompani zemiGodi; belawula nefaraa ezinkulu kwanamizi Mvaliso ngo- kunjalo. Abasebenzi abamhlophe emigodini ba- sebenzisa uMona ukuzuza ngokuphindwe kalishumi kunabamnyama.Kodwa ayingabobonke abamhlophe ababanelo- thamsanqa. Abanye abamhlophe babehluphekule. Belahlekana nemihlaba yabo ngokungxothwa ngo- nofama abatyebileyo. Baya ezidolophini apho bahlala ngokuhlwempuzeka okukhulu njengabobonke abamnyama. Uninzi 1walamahlwempu amhlophe yayi- ngamaBulu.Lamahlwempu amaBulu ayengafundanga engenayo na- nqeqesho ngezoshishino bafumana kunzima uku- fumana imisebenzi. Babanokwenza umsebenzi aba- ngawuqeqeshelwanga kodwa abaqeshi babewunika abemnyama bona babehlawula phantsi. uRulumente wancedisana neqaqobana lalamahlwempu amhlophe angena ngqeqesho ngokuwafunela umsebenzi kwa- Loliwe.
- Full Text:
- Date Issued: 1983-08
The Racists turned their backs
- Authors: John, Hans
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians
- Language: German
- Type: Article
- Identifier: vital:13547 , http://hdl.handle.net/10962/d1006430 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians
- Description: Photocopied article in German about a concert by Chris McGregor and the Brotherhood of Breath at the Hochschule der Künste in Berlin, Germany. There is also a picture of Chris McGregor playing piano on stage.
- Full Text:
- Authors: John, Hans
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians
- Language: German
- Type: Article
- Identifier: vital:13547 , http://hdl.handle.net/10962/d1006430 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians
- Description: Photocopied article in German about a concert by Chris McGregor and the Brotherhood of Breath at the Hochschule der Künste in Berlin, Germany. There is also a picture of Chris McGregor playing piano on stage.
- Full Text:
A statistical model for valuation of residential property in the Nelson Mandela Metropolitan area
- Authors: Van der Byl, Calven
- Date: 2012
- Subjects: Residential real estate -- Port Elizabeth , Housing -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9347 , http://hdl.handle.net/10948/d1020045
- Description: This study applies a process of correlation analysis and hedonic based modelling to investigate the influence of housing attributes and date of sale on transaction prices for residential real estate in the Nelson Mandela Metropole area. Availability of reliable data is a challenge in real estate studies in South Africa. This study integrates several publicly available resources for the purposes of constructing a statistical model. A model is constructed based on a forward variable selection routine using selection criteria. The resulting model shows six highly significant variables that can be used for modelling purposes. The resulting model is used to make comparisons in the value of the geographical location.
- Full Text:
- Date Issued: 2012
- Authors: Van der Byl, Calven
- Date: 2012
- Subjects: Residential real estate -- Port Elizabeth , Housing -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9347 , http://hdl.handle.net/10948/d1020045
- Description: This study applies a process of correlation analysis and hedonic based modelling to investigate the influence of housing attributes and date of sale on transaction prices for residential real estate in the Nelson Mandela Metropole area. Availability of reliable data is a challenge in real estate studies in South Africa. This study integrates several publicly available resources for the purposes of constructing a statistical model. A model is constructed based on a forward variable selection routine using selection criteria. The resulting model shows six highly significant variables that can be used for modelling purposes. The resulting model is used to make comparisons in the value of the geographical location.
- Full Text:
- Date Issued: 2012
A comparison of two township iimbongi: a literary appreciation
- Authors: Ntabeni, Jennifer Nonkoliso
- Date: 2006
- Subjects: Laudatory poetry, Xhosa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8469 , http://hdl.handle.net/10948/583 , Laudatory poetry, Xhosa
- Description: The performance of Xhosa mbongis (no correct English equivalent is available for the Xhosa bard / praise singer) is an interesting art form presentation by some individuals found in the Xhosa community. What is of interest is the fact that such artists are known to be the voices of their communities, heralding socio-cultural and historical norms and achievements. In the olden days, such figures were commonly found in the royal circles of headmen, chiefs and kings. Nowadays, urbanization has brought them into the township where they are gradually assuming different roles of not only focusing on the royal houses, but also in all community leaders as well as non-leaders of the community. Initially they used to earn their reputation through the kings or councils stages / platforms, but these days they also acquire such reputation through media and in any socio-political gatherings. They used to win awards and presents while nowadays they charge appearance fees. It is being changed into a profession albeit without any sort of academic accreditation. In the Nelson Mandela Metropolitan township, a number of such mbongis have mushroomed much against the likings of some purists cultural practitioners. The purists accuse them of being drunk with greed. Perhaps the accusation is justified and perhaps not. What is most notable is the fact that mbongis recite whenever they are asked to do so, something which is not acceptable to purists who believe that an imbongi is called forth to perform when the spirits instruct him or her to stand up and bonga. Whatever the case may be, many of such mbongis appear mostly in funerals, of known and unknown figures and so to many people, they make mockery of such a solemn talent. It is against this background that the researcher felt the need to look into this literary art-form as being presently performed by a township imbongi. The first chapter will deal with introduction, aim of study and method of research. The second chapter will provide a review of oral poetry and a poet in Xhosa writings, the nature of traditional imbongi his or her role in traditional and modern society. The third chapter will give the analysis of content, form and style of two recited poems by two different imbongis. The fourth chapter will provide a brief conclusion on how we view modern traditional imbongis and oral poetry
- Full Text:
- Date Issued: 2006
- Authors: Ntabeni, Jennifer Nonkoliso
- Date: 2006
- Subjects: Laudatory poetry, Xhosa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8469 , http://hdl.handle.net/10948/583 , Laudatory poetry, Xhosa
- Description: The performance of Xhosa mbongis (no correct English equivalent is available for the Xhosa bard / praise singer) is an interesting art form presentation by some individuals found in the Xhosa community. What is of interest is the fact that such artists are known to be the voices of their communities, heralding socio-cultural and historical norms and achievements. In the olden days, such figures were commonly found in the royal circles of headmen, chiefs and kings. Nowadays, urbanization has brought them into the township where they are gradually assuming different roles of not only focusing on the royal houses, but also in all community leaders as well as non-leaders of the community. Initially they used to earn their reputation through the kings or councils stages / platforms, but these days they also acquire such reputation through media and in any socio-political gatherings. They used to win awards and presents while nowadays they charge appearance fees. It is being changed into a profession albeit without any sort of academic accreditation. In the Nelson Mandela Metropolitan township, a number of such mbongis have mushroomed much against the likings of some purists cultural practitioners. The purists accuse them of being drunk with greed. Perhaps the accusation is justified and perhaps not. What is most notable is the fact that mbongis recite whenever they are asked to do so, something which is not acceptable to purists who believe that an imbongi is called forth to perform when the spirits instruct him or her to stand up and bonga. Whatever the case may be, many of such mbongis appear mostly in funerals, of known and unknown figures and so to many people, they make mockery of such a solemn talent. It is against this background that the researcher felt the need to look into this literary art-form as being presently performed by a township imbongi. The first chapter will deal with introduction, aim of study and method of research. The second chapter will provide a review of oral poetry and a poet in Xhosa writings, the nature of traditional imbongi his or her role in traditional and modern society. The third chapter will give the analysis of content, form and style of two recited poems by two different imbongis. The fourth chapter will provide a brief conclusion on how we view modern traditional imbongis and oral poetry
- Full Text:
- Date Issued: 2006
Default in payment, an application of statistical learning techniques
- Authors: Gcakasi, Lulama
- Date: 2020
- Subjects: Credit -- South Africa -- Risk assessment , Risk management -- Statistical methods -- South Africa , Credit -- Management -- Statistical methods , Commercial statistics
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/141547 , vital:37984
- Description: The ability of financial institutions to detect whether a customer will default on their credit card payment is essential for its profitability. To that effect, financial institutions have credit scoring systems in place to be able to estimate the credit risk associated with a customer. Various classification models are used to develop credit scoring systems such as k-nearest neighbours, logistic regression and classification trees. This study aims to assess the performance of different classification models on the prediction of credit card payment default. Credit data is usually of high dimension and as a result dimension reduction techniques, namely principal component analysis and linear discriminant analysis, are used in this study as a means to improve model performance. Two classification models are used, namely neural networks and support vector machines. Model performance is evaluated using accuracy and area under the curve (AUC). The neuarl network classifier performed better than the support vector machine classifier as it produced higher accuracy rates and AUC values. Dimension reduction techniques were not effective in improving model performance but did result in less computationally expensive models.
- Full Text:
- Date Issued: 2020
- Authors: Gcakasi, Lulama
- Date: 2020
- Subjects: Credit -- South Africa -- Risk assessment , Risk management -- Statistical methods -- South Africa , Credit -- Management -- Statistical methods , Commercial statistics
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/141547 , vital:37984
- Description: The ability of financial institutions to detect whether a customer will default on their credit card payment is essential for its profitability. To that effect, financial institutions have credit scoring systems in place to be able to estimate the credit risk associated with a customer. Various classification models are used to develop credit scoring systems such as k-nearest neighbours, logistic regression and classification trees. This study aims to assess the performance of different classification models on the prediction of credit card payment default. Credit data is usually of high dimension and as a result dimension reduction techniques, namely principal component analysis and linear discriminant analysis, are used in this study as a means to improve model performance. Two classification models are used, namely neural networks and support vector machines. Model performance is evaluated using accuracy and area under the curve (AUC). The neuarl network classifier performed better than the support vector machine classifier as it produced higher accuracy rates and AUC values. Dimension reduction techniques were not effective in improving model performance but did result in less computationally expensive models.
- Full Text:
- Date Issued: 2020
Abasebenzi basedokisini eKapa
- ICU
- Authors: ICU
- Date: 1970
- Subjects: Uncatalogued
- Language: Xhosa
- Type: text
- Identifier: http://hdl.handle.net/10962/134467 , vital:37162
- Description: Kule ncwadana sibalisa imbali ende yezitifido zaseKapa. Sibalisa ngezidube-dube zestifido noququzelo lwazo kwi ICU. Okulandelayo, sijonga ekukhuleni kwamandla ezitifido xa zaziququzelwa kumbutho we Cape Town Stevedoring ne Dock Workers Union. Emva Kwemfazwe Yesibini Yehlabathi sibona ubuthathaka bomanyano lwabasebenzi basedokisini kwiminyaka emininzi. Okokugqibela, sibalisa ibali labasebenzi bestifido, ukuzimanya kwabo nemibutho yabasebenzi nokukhula kwabo kwakhona ngowe 1970. , here put any information that you think is important but there is no field for it, if there isnt remove the field
- Full Text:
- Date Issued: 1970
- Authors: ICU
- Date: 1970
- Subjects: Uncatalogued
- Language: Xhosa
- Type: text
- Identifier: http://hdl.handle.net/10962/134467 , vital:37162
- Description: Kule ncwadana sibalisa imbali ende yezitifido zaseKapa. Sibalisa ngezidube-dube zestifido noququzelo lwazo kwi ICU. Okulandelayo, sijonga ekukhuleni kwamandla ezitifido xa zaziququzelwa kumbutho we Cape Town Stevedoring ne Dock Workers Union. Emva Kwemfazwe Yesibini Yehlabathi sibona ubuthathaka bomanyano lwabasebenzi basedokisini kwiminyaka emininzi. Okokugqibela, sibalisa ibali labasebenzi bestifido, ukuzimanya kwabo nemibutho yabasebenzi nokukhula kwabo kwakhona ngowe 1970. , here put any information that you think is important but there is no field for it, if there isnt remove the field
- Full Text:
- Date Issued: 1970