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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Correlating laboratory and pilot scale reflux classification of fine coal / Izak Gerhardus Theron Smith

Smith, Izak Gerhardus Theron January 2015 (has links)
The search for efficient and economical ways to beneficiate fine coal remains an active research area. Recent developments have shown that the reflux classifier can successfully be used on Australian coals, and based on that, a number of pilot plant investigations have been done in South Africa. While pilot scale units are usually used to test the applicability of a new technology on specific coals, a need exists to gather more fundamental data at a laboratory scale in order to save manpower, costs and time. This study has aimed at introducing a way to pre-test material prior to pilot plant trials in the design chain. The study shows that a laboratory water only reflux classifier can be used as a density fractionator, which accurately produces washability data for coal – this was also investigated by Callen et al. (2008). There is also a linear correlation between density cut-point and fluid velocity within the plates. Only when looking at the model proposed in Walton (2011:68), does it become clear that the relationship is indeed slightly curved. Many investigations from laboratory and pilot tests accept the linear relationship, and describe it as slightly curved due to the settling being in the intermediate settling regime (Iveson et al., 2014; Galvin & Lui, 2011). The separation procedures that produce two products – an overflow and underflow – compare well with fractionation results produced. Thus, fractionation results can generate washability data and predict batch separation operations. The laboratory reflux classifier setup is also dependent on particle size, where individual size ranges achieve e.p.m. values of 0.012 and 0.030, while the combined separation efficiency is 0.039. It was, however, found that the respective laboratory scale reflux classifier that was designed and built was not suitable for continuous operation. The vertical fluidisation section was not high enough to enable a steady fluidised bed. This was necessary for density separation within the bed and to produce a significant pressure differential. It is also recommended to obtain a PID controller. / MIng (Chemical Engineering), North-West University, Potchefstroom Campus, 2015
2

Correlating laboratory and pilot scale reflux classification of fine coal / Izak Gerhardus Theron Smith

Smith, Izak Gerhardus Theron January 2015 (has links)
The search for efficient and economical ways to beneficiate fine coal remains an active research area. Recent developments have shown that the reflux classifier can successfully be used on Australian coals, and based on that, a number of pilot plant investigations have been done in South Africa. While pilot scale units are usually used to test the applicability of a new technology on specific coals, a need exists to gather more fundamental data at a laboratory scale in order to save manpower, costs and time. This study has aimed at introducing a way to pre-test material prior to pilot plant trials in the design chain. The study shows that a laboratory water only reflux classifier can be used as a density fractionator, which accurately produces washability data for coal – this was also investigated by Callen et al. (2008). There is also a linear correlation between density cut-point and fluid velocity within the plates. Only when looking at the model proposed in Walton (2011:68), does it become clear that the relationship is indeed slightly curved. Many investigations from laboratory and pilot tests accept the linear relationship, and describe it as slightly curved due to the settling being in the intermediate settling regime (Iveson et al., 2014; Galvin & Lui, 2011). The separation procedures that produce two products – an overflow and underflow – compare well with fractionation results produced. Thus, fractionation results can generate washability data and predict batch separation operations. The laboratory reflux classifier setup is also dependent on particle size, where individual size ranges achieve e.p.m. values of 0.012 and 0.030, while the combined separation efficiency is 0.039. It was, however, found that the respective laboratory scale reflux classifier that was designed and built was not suitable for continuous operation. The vertical fluidisation section was not high enough to enable a steady fluidised bed. This was necessary for density separation within the bed and to produce a significant pressure differential. It is also recommended to obtain a PID controller. / MIng (Chemical Engineering), North-West University, Potchefstroom Campus, 2015
3

Current practices and guidelines for classifying credit risk boundary events : a South African approach / Steenkamp J.

Steenkamp, Jolene January 2011 (has links)
The financial crisis turmoil has exposed notable weakness in the risk management processes of the financial services industry. It has also led to a critical look at the scope of the various risk types as well as the classification of loss events. More importantly, the effects that incorrect risk classification might have on capital requirements are now also examined and taken into account. Boundary events between credit risk and operational risk continue to be a significant source of concern for regulators and the industry in general. The Basel Committee on Banking Supervision (BCBS) requires that boundary events should be treated as credit risk for the purposes of calculating minimum regulatory capital under the Basel II Framework. Such losses will, therefore, not be subject to any operational risk capital charges. However, for the purposes of internal operational risk management, banks are required to identify all material operational risk losses. Boundary events should be flagged separately within a bank’s internal operational risk database. The Basel II Framework does not provide any further guidelines as to what constitutes boundary events and, therefore, consistent guiding principles that banks can follow for accurately classifying and subsequently flagging such events do not exist. The potential exists that actual boundary events might be classified as purely credit risk, and correctly be included in the credit risk capital charge, but not be flagged separately within the bank’s internal operational risk database. Alternatively, boundary events might be classified as operational risk and, therefore, be subject to the operational risk capital charge, instead of the credit risk capital charge. The former instance might give rise to an operational risk manager not being completely informed of the operational risks that the business is facing. The emphasis should always be on the management of risks and for this reason it is important that a financial institution indicates and flags all boundary events in their operational risk systems. To remedy this lack of guidance on the boundary event issue, guidelines are provided that banks can utilise within their risk classification processes. The approach utilised is to consider mechanisms and tools for classification, guidance from the Operational Risk Data Exchange (ORX) and the BCBS, as well as the International Accounting Standards Board (IASB). By compiling and submitting questionnaires to five South African banks, an investigation is conducted in order to obtain a view of the current mechanisms, tools and approaches that South African Advanced Measurement Approach (AMA) banks currently utilise within their classification processes. The effectiveness of boundary event classification is assessed by analysing the percentage of losses classified as boundary. In addition, the degree of uniformity or disparity in the classification of typical boundary event scenarios is considered. This analysis is performed by providing respondents with a total of 16 typical boundary event risk descriptions, and requesting the respondents to classify each of the losses in the scenarios as credit risk, operational risk or boundary event type. / Thesis (M.Com. (Risk management))--North-West University, Potchefstroom Campus, 2012.
4

Current practices and guidelines for classifying credit risk boundary events : a South African approach / Steenkamp J.

Steenkamp, Jolene January 2011 (has links)
The financial crisis turmoil has exposed notable weakness in the risk management processes of the financial services industry. It has also led to a critical look at the scope of the various risk types as well as the classification of loss events. More importantly, the effects that incorrect risk classification might have on capital requirements are now also examined and taken into account. Boundary events between credit risk and operational risk continue to be a significant source of concern for regulators and the industry in general. The Basel Committee on Banking Supervision (BCBS) requires that boundary events should be treated as credit risk for the purposes of calculating minimum regulatory capital under the Basel II Framework. Such losses will, therefore, not be subject to any operational risk capital charges. However, for the purposes of internal operational risk management, banks are required to identify all material operational risk losses. Boundary events should be flagged separately within a bank’s internal operational risk database. The Basel II Framework does not provide any further guidelines as to what constitutes boundary events and, therefore, consistent guiding principles that banks can follow for accurately classifying and subsequently flagging such events do not exist. The potential exists that actual boundary events might be classified as purely credit risk, and correctly be included in the credit risk capital charge, but not be flagged separately within the bank’s internal operational risk database. Alternatively, boundary events might be classified as operational risk and, therefore, be subject to the operational risk capital charge, instead of the credit risk capital charge. The former instance might give rise to an operational risk manager not being completely informed of the operational risks that the business is facing. The emphasis should always be on the management of risks and for this reason it is important that a financial institution indicates and flags all boundary events in their operational risk systems. To remedy this lack of guidance on the boundary event issue, guidelines are provided that banks can utilise within their risk classification processes. The approach utilised is to consider mechanisms and tools for classification, guidance from the Operational Risk Data Exchange (ORX) and the BCBS, as well as the International Accounting Standards Board (IASB). By compiling and submitting questionnaires to five South African banks, an investigation is conducted in order to obtain a view of the current mechanisms, tools and approaches that South African Advanced Measurement Approach (AMA) banks currently utilise within their classification processes. The effectiveness of boundary event classification is assessed by analysing the percentage of losses classified as boundary. In addition, the degree of uniformity or disparity in the classification of typical boundary event scenarios is considered. This analysis is performed by providing respondents with a total of 16 typical boundary event risk descriptions, and requesting the respondents to classify each of the losses in the scenarios as credit risk, operational risk or boundary event type. / Thesis (M.Com. (Risk management))--North-West University, Potchefstroom Campus, 2012.
5

Profiling sectoral risks of foreign direct investment in Africa

Coetzee, Zahné January 2012 (has links)
Attracting foreign direct investment (FDI) is of utmost importance for African countries in order to create employment opportunities, reduce poverty and to ensure sustainable economic growth. Despite Africa’s exceptional FDI performance during the past decade, the majority of FDI inflows have been directed to a few selected countries. As investors face many risks when investing in developing countries it is argued that risk perception plays a vital role in the FDI inflows into Africa. This thesis focuses on the relationship between risk and FDI. A structural equation model is used to analyse this relationship with a dataset of ten risk categories and FDI data from 42 African countries. The importance of SEM for this study lies in the capability of modelling data from multiple groups. Hence, the four sectors used comprise metals, automotive, communications and the real estate sector. Overall results indicate that government effectiveness and legal and regulatory risks produce the biggest concern for investors. The conclusion is that there are different risk patterns regarding FDI in Africa. The empirical results further imply that if African countries wish to attract the levels of FDI required to stimulate economic growth, policies are needed to reduce risks in order to create a favourable investment climate for investors. / Thesis (MCom (International Trade))--North-West University, Potchefstroom Campus, 2013.
6

Profiling sectoral risks of foreign direct investment in Africa

Coetzee, Zahné January 2012 (has links)
Attracting foreign direct investment (FDI) is of utmost importance for African countries in order to create employment opportunities, reduce poverty and to ensure sustainable economic growth. Despite Africa’s exceptional FDI performance during the past decade, the majority of FDI inflows have been directed to a few selected countries. As investors face many risks when investing in developing countries it is argued that risk perception plays a vital role in the FDI inflows into Africa. This thesis focuses on the relationship between risk and FDI. A structural equation model is used to analyse this relationship with a dataset of ten risk categories and FDI data from 42 African countries. The importance of SEM for this study lies in the capability of modelling data from multiple groups. Hence, the four sectors used comprise metals, automotive, communications and the real estate sector. Overall results indicate that government effectiveness and legal and regulatory risks produce the biggest concern for investors. The conclusion is that there are different risk patterns regarding FDI in Africa. The empirical results further imply that if African countries wish to attract the levels of FDI required to stimulate economic growth, policies are needed to reduce risks in order to create a favourable investment climate for investors. / Thesis (MCom (International Trade))--North-West University, Potchefstroom Campus, 2013.
7

The file fragment classification problem : a combined neural network and linear programming discriminant model approach / Erich Feodor Wilgenbus

Wilgenbus, Erich Feodor January 2013 (has links)
The increased use of digital media to store legal, as well as illegal data, has created the need for specialized tools that can monitor, control and even recover this data. An important task in computer forensics and security is to identify the true le type to which a computer le or computer le fragment belongs. File type identi cation is traditionally done by means of metadata, such as le extensions and le header and footer signatures. As a result, traditional metadata-based le object type identi cation techniques work well in cases where the required metadata is available and unaltered. However, traditional approaches are not reliable when the integrity of metadata is not guaranteed or metadata is unavailable. As an alternative, any pattern in the content of a le object can be used to determine the associated le type. This is called content-based le object type identi cation. Supervised learning techniques can be used to infer a le object type classi er by exploiting some unique pattern that underlies a le type's common le structure. This study builds on existing literature regarding the use of supervised learning techniques for content-based le object type identi cation, and explores the combined use of multilayer perceptron neural network classi ers and linear programming-based discriminant classi ers as a solution to the multiple class le fragment type identi cation problem. The purpose of this study was to investigate and compare the use of a single multilayer perceptron neural network classi er, a single linear programming-based discriminant classi- er and a combined ensemble of these classi ers in the eld of le type identi cation. The ability of each individual classi er and the ensemble of these classi ers to accurately predict the le type to which a le fragment belongs were tested empirically. The study found that both a multilayer perceptron neural network and a linear programming- based discriminant classi er (used in a round robin) seemed to perform well in solving the multiple class le fragment type identi cation problem. The results of combining multilayer perceptron neural network classi ers and linear programming-based discriminant classi ers in an ensemble were not better than those of the single optimized classi ers. / MSc (Computer Science), North-West University, Potchefstroom Campus, 2013
8

Profiling the determinants of Indian foreign direct investment in Africa / Susanna Elizabeth Cloete

Cloete, Susanna Elizabeth January 2013 (has links)
India is fast becoming one of the largest economies worldwide, with expectations of becoming the second largest economy by 2050. The growth this country is demonstrating is accompanied by integration with other economies with active engagement in trade and investment in the world economy. Analysts and researchers strive to understand the possible effects of the rise of India on the global economy. The influence of India’s rise on Africa is an arguable topic. The Indo-Africa relationship has a strong political and socio-economic history. This relationship has undergone some changes since 1990 when India started a new approach that included internationalisation. In the modern economy the trade and investment from India to Africa have illustrated fast growth rates. It is claimed that India’s main interest in Africa is to gain access to Africa’s abundant resources with the intention of supporting its economic growth. This creates some concern on the nature of India’s involvement in Africa; whether or not it will increase the development and whether it will put pressure on Africa’s control of its resources. This study focuses on understanding the extent of Indian FDI in Africa and the factors that determine this involvement. Africa is known as the poorest continent worldwide; hence the development should be managed and controlled in order to sustain the growth. The flows of FDI to this continent can provide some advantages that include growth and development, while FDI can also prompt some disadvantages such as resource extraction. Profiling the determinants of Indian FDI in Africa provides an understanding of the influence India may have on Africa. Profiling the determinants of Indian FDI in Africa is done by means of a literature study that identifies the determinants that are applicable to African FDI. These determinants include natural resources, market size, political instability, macro-economic instability, weak policies, inflation, good governance, investment, GDP, growth, openness and oil production. Following the literature study an analysis is done on the trend of FDI worldwide and especially between India and Africa. The overall amount of FDI flows illustrates large increases globally and developed regions account for the majority of FDI flows. The trends of flows illustrate some changes that highlight the prominent role developing countries are starting to play. Africa is classified as a developing region that accounts for a fairly small amount of the total flows to the developing regions. It is noted that Africa’s share is steadily increasing and is expected to keep on rising. Indian FDI to Africa has demonstrated some staggering increases, while India claims to further increase its involvement. India’s FDI mainly flows to the resource sectors such as oil, coal and gas. India also states to expand its FDI involvement into African sectors such as the infrastructure, information technology, computer software, services and telecommunication. Identifying the specific determinants of Indian FDI in Africa is established by estimating models using the Structural Equation Method (SEMs). A combination of a factor analysis and regression analysis is estimated. The specific determinants that influence Indian FDI in Africa include government effectiveness, control of corruption, crude oil price, school enrolment and exports. The level or value of the investments is influenced by the government effectiveness and rule of law. This study concludes that India’s involvement in Africa is increasing. India demonstrates high levels of interest in Africa’s resources, but this is prone to expand across different sectors. / MCom (International Trade), North-West University, Potchefstroom Campus, 2013
9

The file fragment classification problem : a combined neural network and linear programming discriminant model approach / Erich Feodor Wilgenbus

Wilgenbus, Erich Feodor January 2013 (has links)
The increased use of digital media to store legal, as well as illegal data, has created the need for specialized tools that can monitor, control and even recover this data. An important task in computer forensics and security is to identify the true le type to which a computer le or computer le fragment belongs. File type identi cation is traditionally done by means of metadata, such as le extensions and le header and footer signatures. As a result, traditional metadata-based le object type identi cation techniques work well in cases where the required metadata is available and unaltered. However, traditional approaches are not reliable when the integrity of metadata is not guaranteed or metadata is unavailable. As an alternative, any pattern in the content of a le object can be used to determine the associated le type. This is called content-based le object type identi cation. Supervised learning techniques can be used to infer a le object type classi er by exploiting some unique pattern that underlies a le type's common le structure. This study builds on existing literature regarding the use of supervised learning techniques for content-based le object type identi cation, and explores the combined use of multilayer perceptron neural network classi ers and linear programming-based discriminant classi ers as a solution to the multiple class le fragment type identi cation problem. The purpose of this study was to investigate and compare the use of a single multilayer perceptron neural network classi er, a single linear programming-based discriminant classi- er and a combined ensemble of these classi ers in the eld of le type identi cation. The ability of each individual classi er and the ensemble of these classi ers to accurately predict the le type to which a le fragment belongs were tested empirically. The study found that both a multilayer perceptron neural network and a linear programming- based discriminant classi er (used in a round robin) seemed to perform well in solving the multiple class le fragment type identi cation problem. The results of combining multilayer perceptron neural network classi ers and linear programming-based discriminant classi ers in an ensemble were not better than those of the single optimized classi ers. / MSc (Computer Science), North-West University, Potchefstroom Campus, 2013
10

Profiling the determinants of Indian foreign direct investment in Africa / Susanna Elizabeth Cloete

Cloete, Susanna Elizabeth January 2013 (has links)
India is fast becoming one of the largest economies worldwide, with expectations of becoming the second largest economy by 2050. The growth this country is demonstrating is accompanied by integration with other economies with active engagement in trade and investment in the world economy. Analysts and researchers strive to understand the possible effects of the rise of India on the global economy. The influence of India’s rise on Africa is an arguable topic. The Indo-Africa relationship has a strong political and socio-economic history. This relationship has undergone some changes since 1990 when India started a new approach that included internationalisation. In the modern economy the trade and investment from India to Africa have illustrated fast growth rates. It is claimed that India’s main interest in Africa is to gain access to Africa’s abundant resources with the intention of supporting its economic growth. This creates some concern on the nature of India’s involvement in Africa; whether or not it will increase the development and whether it will put pressure on Africa’s control of its resources. This study focuses on understanding the extent of Indian FDI in Africa and the factors that determine this involvement. Africa is known as the poorest continent worldwide; hence the development should be managed and controlled in order to sustain the growth. The flows of FDI to this continent can provide some advantages that include growth and development, while FDI can also prompt some disadvantages such as resource extraction. Profiling the determinants of Indian FDI in Africa provides an understanding of the influence India may have on Africa. Profiling the determinants of Indian FDI in Africa is done by means of a literature study that identifies the determinants that are applicable to African FDI. These determinants include natural resources, market size, political instability, macro-economic instability, weak policies, inflation, good governance, investment, GDP, growth, openness and oil production. Following the literature study an analysis is done on the trend of FDI worldwide and especially between India and Africa. The overall amount of FDI flows illustrates large increases globally and developed regions account for the majority of FDI flows. The trends of flows illustrate some changes that highlight the prominent role developing countries are starting to play. Africa is classified as a developing region that accounts for a fairly small amount of the total flows to the developing regions. It is noted that Africa’s share is steadily increasing and is expected to keep on rising. Indian FDI to Africa has demonstrated some staggering increases, while India claims to further increase its involvement. India’s FDI mainly flows to the resource sectors such as oil, coal and gas. India also states to expand its FDI involvement into African sectors such as the infrastructure, information technology, computer software, services and telecommunication. Identifying the specific determinants of Indian FDI in Africa is established by estimating models using the Structural Equation Method (SEMs). A combination of a factor analysis and regression analysis is estimated. The specific determinants that influence Indian FDI in Africa include government effectiveness, control of corruption, crude oil price, school enrolment and exports. The level or value of the investments is influenced by the government effectiveness and rule of law. This study concludes that India’s involvement in Africa is increasing. India demonstrates high levels of interest in Africa’s resources, but this is prone to expand across different sectors. / MCom (International Trade), North-West University, Potchefstroom Campus, 2013

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