A multiscale remote sensing assessment of subtropical indigenous forests along the wild coast, South Africa
- Authors: Blessing, Sithole Vhusomuzi
- Date: 2015
- Subjects: Forests and forestry -- South Africa -- Remote sensing , Forest conservation , Remote sensing , Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10677 , http://hdl.handle.net/10948/d1021169
- Description: The subtropical forests located along South Africa’s Wild Coast region, declared as one of the biodiversity hotspots, provide benefits to the local and national economy. However, there is evidence of increased pressure exerted on the forests by growing population and reduced income from activities not related to forest products. The ability of remote sensing to quantify subtropical forest changes over time, perform species discrimination (using field spectroscopy) and integrating field spectral and multispectral data were all assessed in this study. Investigations were conducted at pixel, leaf and sub-pixel levels. Both per-pixel and sub-pixel classification methods were used for improved forest characterisation. Using SPOT 6 imagery for 2013, the study determined the best classification algorithm for mapping sub-tropical forest and other land cover types to be the maximum likelihood classifier. Maximum likelihood outperformed minimum distance, spectral angle mapper and spectral information divergence algorithms, based on overall accuracy and Kappa coefficient values. Forest change analysis was made based on spectral measurements made at top of the atmosphere (TOC) level. When applied to the 2005 and 2009 SPOT 5 images, subtropical forest changes between 2005-2009 and 2009-2013 were quantified. A temporal analysis of forest cover trends in the periods 2005-2009 and 2009-2013 identified a decreasing trend of -3648.42 and -946.98 ha respectively, which translated to 7.81 percent and 2.20 percent decrease. Although there is evidence of a trend towards decreased rates of forest loss, more conservation efforts are required to protect the Wild Coast ecosystem. Using field spectral measurements data, the hierarchical method (comprising One-way ANOVA with Bonferroni correction, Classification and Regression Trees (CART) and Jeffries Matusita method) successfully selected optimal wavelengths for species discrimination at leaf level. Only 17 out of 2150 wavelengths were identified, thereby reducing the complexities related to data dimensionality. The optimal 17 wavelength bands were noted in the visible (438, 442, 512 and 695 nm), near infrared (724, 729, 750, 758, 856, 936, 1179, 1507 and 1673 nm) and mid-infrared (2220, 2465, 2469 and 2482 nm) portions of the electromagnetic spectrum. The Jeffries-Matusita (JM) distance method confirmed the separability of the selected wavelength bands. Using these 17 wavelengths, linear discriminant analysis (LDA) classified subtropical species at leaf level more accurately than partial least squares discriminant analysis (PLSDA) and random forest (RF). In addition, the study integrated field-collected canopy spectral and multispectral data to discriminate proportions of semi-deciduous and evergreen subtropical forests at sub-pixel level. By using the 2013 land cover (using MLC) to mask non-forested portions before sub-pixel classification (using MTMF), the proportional maps were a product of two classifiers. The proportional maps show higher proportions of evergreen forests along the coast while semi-deciduous subtropical forest species were mainly on inland parts of the Wild Coast. These maps had high accuracy, thereby proving the ability of an integration of field spectral and multispectral data in mapping semi-deciduous and evergreen forest species. Overall, the study has demonstrated the importance of the MLC and LDA and served to integrate field spectral and multispectral data in subtropical forest characterisation at both leaf and top-of-atmosphere levels. The success of both the MLC and LDA further highlighted how essential parametric classifiers are in remote sensing forestry applications. Main subtropical characteristics highlighted in this study were species discrimination at leaf level, quantifying forest change at pixel level and discriminating semi-deciduous and evergreen forests at sub-pixel level.
- Full Text:
- Date Issued: 2015
- Authors: Blessing, Sithole Vhusomuzi
- Date: 2015
- Subjects: Forests and forestry -- South Africa -- Remote sensing , Forest conservation , Remote sensing , Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10677 , http://hdl.handle.net/10948/d1021169
- Description: The subtropical forests located along South Africa’s Wild Coast region, declared as one of the biodiversity hotspots, provide benefits to the local and national economy. However, there is evidence of increased pressure exerted on the forests by growing population and reduced income from activities not related to forest products. The ability of remote sensing to quantify subtropical forest changes over time, perform species discrimination (using field spectroscopy) and integrating field spectral and multispectral data were all assessed in this study. Investigations were conducted at pixel, leaf and sub-pixel levels. Both per-pixel and sub-pixel classification methods were used for improved forest characterisation. Using SPOT 6 imagery for 2013, the study determined the best classification algorithm for mapping sub-tropical forest and other land cover types to be the maximum likelihood classifier. Maximum likelihood outperformed minimum distance, spectral angle mapper and spectral information divergence algorithms, based on overall accuracy and Kappa coefficient values. Forest change analysis was made based on spectral measurements made at top of the atmosphere (TOC) level. When applied to the 2005 and 2009 SPOT 5 images, subtropical forest changes between 2005-2009 and 2009-2013 were quantified. A temporal analysis of forest cover trends in the periods 2005-2009 and 2009-2013 identified a decreasing trend of -3648.42 and -946.98 ha respectively, which translated to 7.81 percent and 2.20 percent decrease. Although there is evidence of a trend towards decreased rates of forest loss, more conservation efforts are required to protect the Wild Coast ecosystem. Using field spectral measurements data, the hierarchical method (comprising One-way ANOVA with Bonferroni correction, Classification and Regression Trees (CART) and Jeffries Matusita method) successfully selected optimal wavelengths for species discrimination at leaf level. Only 17 out of 2150 wavelengths were identified, thereby reducing the complexities related to data dimensionality. The optimal 17 wavelength bands were noted in the visible (438, 442, 512 and 695 nm), near infrared (724, 729, 750, 758, 856, 936, 1179, 1507 and 1673 nm) and mid-infrared (2220, 2465, 2469 and 2482 nm) portions of the electromagnetic spectrum. The Jeffries-Matusita (JM) distance method confirmed the separability of the selected wavelength bands. Using these 17 wavelengths, linear discriminant analysis (LDA) classified subtropical species at leaf level more accurately than partial least squares discriminant analysis (PLSDA) and random forest (RF). In addition, the study integrated field-collected canopy spectral and multispectral data to discriminate proportions of semi-deciduous and evergreen subtropical forests at sub-pixel level. By using the 2013 land cover (using MLC) to mask non-forested portions before sub-pixel classification (using MTMF), the proportional maps were a product of two classifiers. The proportional maps show higher proportions of evergreen forests along the coast while semi-deciduous subtropical forest species were mainly on inland parts of the Wild Coast. These maps had high accuracy, thereby proving the ability of an integration of field spectral and multispectral data in mapping semi-deciduous and evergreen forest species. Overall, the study has demonstrated the importance of the MLC and LDA and served to integrate field spectral and multispectral data in subtropical forest characterisation at both leaf and top-of-atmosphere levels. The success of both the MLC and LDA further highlighted how essential parametric classifiers are in remote sensing forestry applications. Main subtropical characteristics highlighted in this study were species discrimination at leaf level, quantifying forest change at pixel level and discriminating semi-deciduous and evergreen forests at sub-pixel level.
- Full Text:
- Date Issued: 2015
The management of the antecedents of absenteeism at a motor manufacturing company
- Authors: Mandleni, Oscar
- Date: 2011
- Subjects: Absenteeism (Labor) , Motor industry , Production management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8755 , http://hdl.handle.net/10948/d1011559 , Absenteeism (Labor) , Motor industry , Production management
- Description: Absenteeism is a complex set of behaviours masquerading as a unitary phenomenon. Absenteeism is a big problem in the motor manufacturing industry, especially, because of the number of processes that are labour intensive. Absenteeism is a multifaceted problem with many antecedents which make it challenging to resolve or contain. Financial impact is one of the consequences of absenteeism on a business, especially when one thinks that the primary objective of a firm in to make money. Absenteeism defeats these objectives through cost incurred for overtime to catch up production losses. Furthermore, in cases where replacement of personnel is necessary, this may include administrative costs related to the time human resource personnel spend looking for replacement employees or the time production management spends re-assigning employees. Absenteeism results in decreased productivity and may affect the quality of the product due to the increased workload and burden put on employees who are at work. Absenteeism is classified into scheduled and unscheduled absenteeism. Although some absenteeism is avoidable, it is important to understand that some absence is unavoidable. This is because people may fall ill, get injured or have unavoidable obligations which may lead to absenteeism. The purpose of this study was to identify the antecedents of absenteeism, with the assumption that once they are identified, they can be controlled, reduced or eliminated and the absenteeism rate thus reduced. The theoretical study focused on defining absenteeism, ascertaining the impact of absenteeism in the workplace, especially in an international organisation in the motor manufacturing industry and discussing the antecedents of absenteeism and strategies that can be used to manage these antecedents. The empirical study consisted of a survey, with a questionnaire as a data collecting tool. The process used to conduct the survey was to distribute the questionnaire among production employees in three operational units; namely Final Assembly, Paint Shop and Body Shop at a motor manufacturing company. Employees were approached, the purpose of the questionnaire explained and they were asked if they would be willing to complete the questionnaire. Employees who agreed to complete the questionnaire were briefed on the contents of the questionnaire and the completion process. The relationship between biographical variables and absenteeism was discussed. For the purpose of this study the following independent variables were discussed: age, marital status, gender, work area, length of service and number of dependents. The empirical study focused on the antecedents of absenteeism, and specifically job, organisational and personal factors, as well supervisors‟ attempts to manage absenteeism. The respondents indicated that they believed absenteeism was a problem in the study and that people stayed away for reasons other than genuine illness. It was recommended that absenteeism figures, such as the overall Gross Absence Rate (GAR) and Absence Frequency Rate for the organisation, and specific work areas and teams, are regularly communicated to employees and displayed prominently to emphasise the importance of attendance. Some suggestions were that: Supervisors should foster a genuinely respectful relationship between themselves and employees which will results in employees feeling obliged to be at work. The company should introduce a day care or crèche at work to allow female employees to bring their kids to work in the event they are unable to be looked after at home. Alcohol and drug abuse should not be seen as an external problem in the organisation but rather as something an organisation should get involved in to assist employee who might have a problem. The first step was to create a channel where employee can feel free to approach the company if they are in need of help. The study demonstrated that it was important to identify antecedents in order to address the real problems related to absenteeism.
- Full Text:
- Date Issued: 2011
- Authors: Mandleni, Oscar
- Date: 2011
- Subjects: Absenteeism (Labor) , Motor industry , Production management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8755 , http://hdl.handle.net/10948/d1011559 , Absenteeism (Labor) , Motor industry , Production management
- Description: Absenteeism is a complex set of behaviours masquerading as a unitary phenomenon. Absenteeism is a big problem in the motor manufacturing industry, especially, because of the number of processes that are labour intensive. Absenteeism is a multifaceted problem with many antecedents which make it challenging to resolve or contain. Financial impact is one of the consequences of absenteeism on a business, especially when one thinks that the primary objective of a firm in to make money. Absenteeism defeats these objectives through cost incurred for overtime to catch up production losses. Furthermore, in cases where replacement of personnel is necessary, this may include administrative costs related to the time human resource personnel spend looking for replacement employees or the time production management spends re-assigning employees. Absenteeism results in decreased productivity and may affect the quality of the product due to the increased workload and burden put on employees who are at work. Absenteeism is classified into scheduled and unscheduled absenteeism. Although some absenteeism is avoidable, it is important to understand that some absence is unavoidable. This is because people may fall ill, get injured or have unavoidable obligations which may lead to absenteeism. The purpose of this study was to identify the antecedents of absenteeism, with the assumption that once they are identified, they can be controlled, reduced or eliminated and the absenteeism rate thus reduced. The theoretical study focused on defining absenteeism, ascertaining the impact of absenteeism in the workplace, especially in an international organisation in the motor manufacturing industry and discussing the antecedents of absenteeism and strategies that can be used to manage these antecedents. The empirical study consisted of a survey, with a questionnaire as a data collecting tool. The process used to conduct the survey was to distribute the questionnaire among production employees in three operational units; namely Final Assembly, Paint Shop and Body Shop at a motor manufacturing company. Employees were approached, the purpose of the questionnaire explained and they were asked if they would be willing to complete the questionnaire. Employees who agreed to complete the questionnaire were briefed on the contents of the questionnaire and the completion process. The relationship between biographical variables and absenteeism was discussed. For the purpose of this study the following independent variables were discussed: age, marital status, gender, work area, length of service and number of dependents. The empirical study focused on the antecedents of absenteeism, and specifically job, organisational and personal factors, as well supervisors‟ attempts to manage absenteeism. The respondents indicated that they believed absenteeism was a problem in the study and that people stayed away for reasons other than genuine illness. It was recommended that absenteeism figures, such as the overall Gross Absence Rate (GAR) and Absence Frequency Rate for the organisation, and specific work areas and teams, are regularly communicated to employees and displayed prominently to emphasise the importance of attendance. Some suggestions were that: Supervisors should foster a genuinely respectful relationship between themselves and employees which will results in employees feeling obliged to be at work. The company should introduce a day care or crèche at work to allow female employees to bring their kids to work in the event they are unable to be looked after at home. Alcohol and drug abuse should not be seen as an external problem in the organisation but rather as something an organisation should get involved in to assist employee who might have a problem. The first step was to create a channel where employee can feel free to approach the company if they are in need of help. The study demonstrated that it was important to identify antecedents in order to address the real problems related to absenteeism.
- Full Text:
- Date Issued: 2011
Soul tattoos : an exploration of the therapeutic self - the indelible and the disposable
- Authors: Naidoo, Leanne
- Date: 2005
- Subjects: Tattooing -- Therapeutic use
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9842 , http://hdl.handle.net/10948/373 , Tattooing -- Therapeutic use
- Description: From a social constructionist perspective, the self of the therapist is the only tool that she takes into therapy with her. The study of the therapeutic self therefore becomes important as this impacts on the quality of therapy received by the client. This treatise explores the development of the researcher’s therapeutic self through the storying of significant learning experiences in the course of her training in counselling psychology. An analysis of the narrative reveals the substance of some of the soul tattoos that make up her therapeutic self. The study was undertaken from an action research approach, thus emphasising the investigation of the therapeutic self in the field and feeding this information back into the practice of counselling psychology in the course of the research project. The themes extracted in the analysis reveal the process of action learning and what constituted significant learning experiences for the researcher. The researcher found that certain conditions were required for the formation of soul tattoos and that merely obtaining a masters degree in counselling psychology was not sufficient preparation for the practice of counselling psychology.
- Full Text:
- Date Issued: 2005
- Authors: Naidoo, Leanne
- Date: 2005
- Subjects: Tattooing -- Therapeutic use
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9842 , http://hdl.handle.net/10948/373 , Tattooing -- Therapeutic use
- Description: From a social constructionist perspective, the self of the therapist is the only tool that she takes into therapy with her. The study of the therapeutic self therefore becomes important as this impacts on the quality of therapy received by the client. This treatise explores the development of the researcher’s therapeutic self through the storying of significant learning experiences in the course of her training in counselling psychology. An analysis of the narrative reveals the substance of some of the soul tattoos that make up her therapeutic self. The study was undertaken from an action research approach, thus emphasising the investigation of the therapeutic self in the field and feeding this information back into the practice of counselling psychology in the course of the research project. The themes extracted in the analysis reveal the process of action learning and what constituted significant learning experiences for the researcher. The researcher found that certain conditions were required for the formation of soul tattoos and that merely obtaining a masters degree in counselling psychology was not sufficient preparation for the practice of counselling psychology.
- Full Text:
- Date Issued: 2005
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