The influence of controlled fire on the mobilization of Potentially Toxic Elements (PTE) in a mined landscape : Implications for land management and environmental health
- Authors: Abraham, Joji
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Controlled fires conducted in fire prone areas are an efficient and economic option to reduce the frequency and intensity of wild fires that result in damage to human property, infrastructure and ecosystems. However, in a similar way to wild fires, controlled fires affect many of the physical and bio-geochemical properties of the forest soil, and may remobilize Potentially Toxic Elements (PTE) from vegetation and soil organic matter. The objective of this study is to investigate the mobilization of PTEs in a mined landscape after a controlled fire and to describe their temporal variations in concentrations. Soil samples were collected two days before and two days after the controlled fire, at the end of each season, and after a major rainfall in September 2016, from a legacy mine site in Maldon, Central Victoria, Australia, and analysed for PTE concentrations. The results revealed PTE mobility after the controlled fire, and most of the PTEs (As, Cd, Cu, Mn, and Zn) evidenced an increase in concentration (1.2, 1.5, 1.1, 2.9, and 1.7 times respectively) and other PTEs (Hg, Cr and Pb) shown a decrease (1.4, 1.1 and 1.1 times respectively) immediately after the fire. The increase in PTE concentration immediately after the fire is postulated to be associated with the addition of PTE enriched ash to the soil and the reduction is due to the volatilization of elements during fire. The PTEs, which increased their concentrations immediately after the fire show a temporal decrease in concentration in the post-fire soil environment due to the removal of ash and surface soil by rainfall runoff, leaching and wind activity. However, Hg shows an increase in concentration after the major rainfall event. Although, median concentrations of As, Hg, Pb, Cu and Zn exceeded the Australian and Victorian top soil averages, only As and Hg are considered to be a risk to human and aquatic ecosystems health due to their elevated concentration and toxicity. Climate change and the resulting projection for increased forest fire frequency illustrates a growing concern given the expected concomitant increase in PTE mobilization. Preparing appropriate land and water management strategies, and addressing environmental health practice and policy, specifically at the legacy mining areas require a review. This study highlights the significant risk these sites pose.
- Description: Doctor of Philosophy
- Authors: Abraham, Joji
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Controlled fires conducted in fire prone areas are an efficient and economic option to reduce the frequency and intensity of wild fires that result in damage to human property, infrastructure and ecosystems. However, in a similar way to wild fires, controlled fires affect many of the physical and bio-geochemical properties of the forest soil, and may remobilize Potentially Toxic Elements (PTE) from vegetation and soil organic matter. The objective of this study is to investigate the mobilization of PTEs in a mined landscape after a controlled fire and to describe their temporal variations in concentrations. Soil samples were collected two days before and two days after the controlled fire, at the end of each season, and after a major rainfall in September 2016, from a legacy mine site in Maldon, Central Victoria, Australia, and analysed for PTE concentrations. The results revealed PTE mobility after the controlled fire, and most of the PTEs (As, Cd, Cu, Mn, and Zn) evidenced an increase in concentration (1.2, 1.5, 1.1, 2.9, and 1.7 times respectively) and other PTEs (Hg, Cr and Pb) shown a decrease (1.4, 1.1 and 1.1 times respectively) immediately after the fire. The increase in PTE concentration immediately after the fire is postulated to be associated with the addition of PTE enriched ash to the soil and the reduction is due to the volatilization of elements during fire. The PTEs, which increased their concentrations immediately after the fire show a temporal decrease in concentration in the post-fire soil environment due to the removal of ash and surface soil by rainfall runoff, leaching and wind activity. However, Hg shows an increase in concentration after the major rainfall event. Although, median concentrations of As, Hg, Pb, Cu and Zn exceeded the Australian and Victorian top soil averages, only As and Hg are considered to be a risk to human and aquatic ecosystems health due to their elevated concentration and toxicity. Climate change and the resulting projection for increased forest fire frequency illustrates a growing concern given the expected concomitant increase in PTE mobilization. Preparing appropriate land and water management strategies, and addressing environmental health practice and policy, specifically at the legacy mining areas require a review. This study highlights the significant risk these sites pose.
- Description: Doctor of Philosophy
Causes, magnitude and implications of Griefing in Massively Multiplayer Online Role-Playing Games
- Authors: Achterbosch, Leigh
- Date: 2015
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis presents findings from research into the global phenomenon known as griefing that occurs in Massively Multiplayer Online Role-Playing Games (MMORPGs). Griefing, in its simplest terms, refers to the act of one player intentionally disrupting another player’s game experience for personal pleasure and potential gain. For too long it has been unknown how pervasive griefing is, how frequently griefing occurs and, in particular, the impact on players that are subjected to griefing. There has also been limited research regarding what causes a player to perform griefing. This thesis addresses these concerns by answering the research question “What are the causes and implications of griefing in Massively Multiplayer Online Role-Playing Games, and what magnitude of griefing exists in this genre?” Mixed method research was employed using the “Sequential Explanatory Strategy”, in which a quantitative phase was followed by a qualitative phase to strengthen the findings. The quantitative phase consisted of a survey that attracted 1188 participants of a representative player population. The qualitative phase consisted of interviews with 15 participants to give more personalised data. The data was analysed from the perspectives of different demographics and different associations to griefing. The thesis contributed original findings regarding the causes, magnitude and implications of griefing in MMORPGs. Some of the main findings were: • Factors that motivated a player to cause grief; • how griefers selected their targets based on particular demographics or avatar characteristics; • the pervasiveness, frequency and impact of different types of griefing; • the amount of griefing that can be tolerated; • how players reacted to griefing; • the impact to the well-being of the players after a griefing incident. The thesis concluded with advice to MMORPG developers regarding the most pervasive, frequent and impactful types of griefing, and how game design may increase or decrease the amount and intensity of griefing.
- Description: Doctor of Philosophy
- Authors: Achterbosch, Leigh
- Date: 2015
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis presents findings from research into the global phenomenon known as griefing that occurs in Massively Multiplayer Online Role-Playing Games (MMORPGs). Griefing, in its simplest terms, refers to the act of one player intentionally disrupting another player’s game experience for personal pleasure and potential gain. For too long it has been unknown how pervasive griefing is, how frequently griefing occurs and, in particular, the impact on players that are subjected to griefing. There has also been limited research regarding what causes a player to perform griefing. This thesis addresses these concerns by answering the research question “What are the causes and implications of griefing in Massively Multiplayer Online Role-Playing Games, and what magnitude of griefing exists in this genre?” Mixed method research was employed using the “Sequential Explanatory Strategy”, in which a quantitative phase was followed by a qualitative phase to strengthen the findings. The quantitative phase consisted of a survey that attracted 1188 participants of a representative player population. The qualitative phase consisted of interviews with 15 participants to give more personalised data. The data was analysed from the perspectives of different demographics and different associations to griefing. The thesis contributed original findings regarding the causes, magnitude and implications of griefing in MMORPGs. Some of the main findings were: • Factors that motivated a player to cause grief; • how griefers selected their targets based on particular demographics or avatar characteristics; • the pervasiveness, frequency and impact of different types of griefing; • the amount of griefing that can be tolerated; • how players reacted to griefing; • the impact to the well-being of the players after a griefing incident. The thesis concluded with advice to MMORPG developers regarding the most pervasive, frequent and impactful types of griefing, and how game design may increase or decrease the amount and intensity of griefing.
- Description: Doctor of Philosophy
Shared value priorities in groups : The impact of the Bahá’i Faith on Values
- Authors: Afshar, Faezeh
- Date: 2012
- Type: Text , Thesis , PhD
- Full Text:
- Description: Values such as honesty, meaning in life, pleasure, justice and freedom are guiding principles in motivating the selection and evaluation of individual behaviour and goals. They are also important for understanding cultural norms, attitudes and practices. In previous studies individuals and groups have often been found to be willing to subordinate their values toward goals and behaviours that are aligned with their own group; their ‘in-group’. Studies of values within a group have not reported evidence for the subordination of their values toward universal goals and behaviours; their ‘out-groups’. This research is the first to examine widely the values held by adherents of the Bahá’i Faith; a world-wide religious community that envisions a united global society. The main aim of this thesis is to discover and explain the system of value priorities held by Bahá’is. Data was obtained from an online survey of over one thousand responses to the cross-culturally validated ‘Schwartz Value Survey’. Data relating to the degree of commitment to religion referred to as religiosity, was also collected in addition to demographic information.
- Description: Doctor of Philosophy
- Authors: Afshar, Faezeh
- Date: 2012
- Type: Text , Thesis , PhD
- Full Text:
- Description: Values such as honesty, meaning in life, pleasure, justice and freedom are guiding principles in motivating the selection and evaluation of individual behaviour and goals. They are also important for understanding cultural norms, attitudes and practices. In previous studies individuals and groups have often been found to be willing to subordinate their values toward goals and behaviours that are aligned with their own group; their ‘in-group’. Studies of values within a group have not reported evidence for the subordination of their values toward universal goals and behaviours; their ‘out-groups’. This research is the first to examine widely the values held by adherents of the Bahá’i Faith; a world-wide religious community that envisions a united global society. The main aim of this thesis is to discover and explain the system of value priorities held by Bahá’is. Data was obtained from an online survey of over one thousand responses to the cross-culturally validated ‘Schwartz Value Survey’. Data relating to the degree of commitment to religion referred to as religiosity, was also collected in addition to demographic information.
- Description: Doctor of Philosophy
A computer-mediated framework to facilitate group consensus based on a shared understanding ConSULT
- Authors: Afshar, Faezeh
- Date: 2004
- Type: Text , Thesis , Masters , PhD
- Full Text: false
- Description: "Group decision-making usually involves a process of discussion and evaluation of alternatives. Important aspects of a group decision support system are: freedom to participate; the ability to explicitly present points of view; the ability to augment or oppose views by supporting evidence and reasoning; and the ability to use and consider other additional views .... The overall aim of this work is to develop an approach that can alleviate some of the problems associated with group commuication and consensus decision-making by effectively supporting group discussions towards consensus. Towards achieving this goal we have developed an approach called ConSULT (Consensus based on a Shared Understanding of a Leading Topic) as a computer-mediated framework to allow argumentation, collection and evaluation of discussion and group decision-making. This approach employs existing theories and techniques in computer-mediated communication, argumentation, Delphi and voting." -- Abstract.
- Description: Master of Information Technology
- Description: "Group decision-making usually involves a process of discussion and evaluation of alternatives. Important aspects of a group decision support system are: freedom to participate; the ability to explicitly present points of view; the ability to augment or oppose views by supporting evidence and reasoning; and the ability to use and consider other additional views .... The overall aim of this work is to develop an approach that can alleviate some of the problems associated with group commuication and consensus decision-making by effectively supporting group discussions towards consensus. Towards achieveing this goal we have developed an approach called ConSULT (Consensus based on a Shared Understanding of a Leading Topic) as a computer-mediated framework to allow argumentation, collection and evaluation of discussion and group decision-making. This approach employs existing theories and techniques in computer-mediated communication, argumentation, Delphi and voting." -- Abstract.
- Authors: Afshar, Faezeh
- Date: 2004
- Type: Text , Thesis , Masters , PhD
- Full Text: false
- Description: "Group decision-making usually involves a process of discussion and evaluation of alternatives. Important aspects of a group decision support system are: freedom to participate; the ability to explicitly present points of view; the ability to augment or oppose views by supporting evidence and reasoning; and the ability to use and consider other additional views .... The overall aim of this work is to develop an approach that can alleviate some of the problems associated with group commuication and consensus decision-making by effectively supporting group discussions towards consensus. Towards achieving this goal we have developed an approach called ConSULT (Consensus based on a Shared Understanding of a Leading Topic) as a computer-mediated framework to allow argumentation, collection and evaluation of discussion and group decision-making. This approach employs existing theories and techniques in computer-mediated communication, argumentation, Delphi and voting." -- Abstract.
- Description: Master of Information Technology
- Description: "Group decision-making usually involves a process of discussion and evaluation of alternatives. Important aspects of a group decision support system are: freedom to participate; the ability to explicitly present points of view; the ability to augment or oppose views by supporting evidence and reasoning; and the ability to use and consider other additional views .... The overall aim of this work is to develop an approach that can alleviate some of the problems associated with group commuication and consensus decision-making by effectively supporting group discussions towards consensus. Towards achieveing this goal we have developed an approach called ConSULT (Consensus based on a Shared Understanding of a Leading Topic) as a computer-mediated framework to allow argumentation, collection and evaluation of discussion and group decision-making. This approach employs existing theories and techniques in computer-mediated communication, argumentation, Delphi and voting." -- Abstract.
The role of immune cells in ovarian cancer
- Authors: Ahmady, Farah
- Date: 2022
- Type: Text , Thesis , PhD
- Full Text:
- Description: Ovarian cancer remains the leading cause of gynaecological disease related death in women worldwide. Patients given standard treatment have low survival rates and immunotherapy remains unsuccessful. This is largely due to the suppressive tumour microenvironment (TME) and the interaction of the different cells being poorly understood. This has sparked interest in understanding the functions of immune cells and their contribution to the TME. In chapter 3, B and T cells were characterised in samples collected from chemo-naïve highgrade serous ovarian cancer (HGSOC) patients and compared to benign and healthy controls. B cells were able to express the T cell exhaustion marker T cell immunoglobulin and mucin domain-3 (TIM-3) on their surface. Blood derived B cells of benign patients expressed less TIM-3 compared to high-grade and healthy donors. Alterations in TIM-3 expression on B cells suggests that the TME may not be causing B cells to harbour an exhaustion phenotype. The frequency of circulating mucosal-associated invariant T cells (MAIT cells) was reduced in benign and high-grade patients compared to healthy donors. Blood derived MAIT cells of healthy donors stimulated with 5-OP-RU antigen and cultured with ovarian cancer cell line supernatants had a reduced capacity of producing tumour necrosis factor (TNF)-a compared to control. The reduced frequency of MAIT cells at the premalignant state of the disease indicates that malignancy of the disease is not necessarily the contributing factor in the reduction observed. As TNF-a is a key anti-tumour cytokine expressed by MAIT cells, the impaired production may indicate defects in their function. Low dose-dense (LDD) chemotherapy has recently shown promise as depicted in a clinical study by Kannourakis et al. where LDD treated HGSOC patients had longer survival than those treated with maximum tolerated dose (MTD). It is postulated that this may be due to aspects of the immune system, however the effects of LDD chemotherapy on immune cells remains unknown. In chpter 4, circulating B and T cells of LDD treated patients were characterised and compared to untreated controls. The key finding of this study was the immunostimulatory attributes of LDD regimen in a range of B and T cell populations via their increased expression of TNF-a compared to untreated controls and healthy donors. The frequency of MAIT cells, however, was reduced in LDD treated patients, suggesting that these cells may not contribute to the immunostimulatory aspects, and that this regimen may impact their frequency by creating an environment which may not be compatible for MAIT cell survival. In chapter 5, expression of immuno-oncology protein markers in benign and high-grade primary and metastasised tumours were determined for alterations in hot and cold tumour regions using Digital Spatial Profiling (DSP). An increased expression of immune cell, costimulatory and inhibitory markers were apparent in high-grade tumours compared to benign. The stimulator of interferon genes (STING) marker was studied further, and its expression was also higher in high-grade tumours compared to benign, with cisplatin further enhancing its expression in ovarian cancer cell lines. There were alterations in the expression of some downstream molecules, however interferon (IFN)-b, the key cytokine produced in the activated STING pathway, was virtually non-existent. This suggests a defect in the pathway which if restored, may contribute to some of the known anti-tumour functions of the pathway. The results from these studies provide an understanding of differences in the immune profile of non-malignant and malignant ovarian cancer. These findings work together to improve our understanding of the unique TME with the aim to identify potential immune therapeutic targets for future study.
- Description: Doctor of Philosophy
- Authors: Ahmady, Farah
- Date: 2022
- Type: Text , Thesis , PhD
- Full Text:
- Description: Ovarian cancer remains the leading cause of gynaecological disease related death in women worldwide. Patients given standard treatment have low survival rates and immunotherapy remains unsuccessful. This is largely due to the suppressive tumour microenvironment (TME) and the interaction of the different cells being poorly understood. This has sparked interest in understanding the functions of immune cells and their contribution to the TME. In chapter 3, B and T cells were characterised in samples collected from chemo-naïve highgrade serous ovarian cancer (HGSOC) patients and compared to benign and healthy controls. B cells were able to express the T cell exhaustion marker T cell immunoglobulin and mucin domain-3 (TIM-3) on their surface. Blood derived B cells of benign patients expressed less TIM-3 compared to high-grade and healthy donors. Alterations in TIM-3 expression on B cells suggests that the TME may not be causing B cells to harbour an exhaustion phenotype. The frequency of circulating mucosal-associated invariant T cells (MAIT cells) was reduced in benign and high-grade patients compared to healthy donors. Blood derived MAIT cells of healthy donors stimulated with 5-OP-RU antigen and cultured with ovarian cancer cell line supernatants had a reduced capacity of producing tumour necrosis factor (TNF)-a compared to control. The reduced frequency of MAIT cells at the premalignant state of the disease indicates that malignancy of the disease is not necessarily the contributing factor in the reduction observed. As TNF-a is a key anti-tumour cytokine expressed by MAIT cells, the impaired production may indicate defects in their function. Low dose-dense (LDD) chemotherapy has recently shown promise as depicted in a clinical study by Kannourakis et al. where LDD treated HGSOC patients had longer survival than those treated with maximum tolerated dose (MTD). It is postulated that this may be due to aspects of the immune system, however the effects of LDD chemotherapy on immune cells remains unknown. In chpter 4, circulating B and T cells of LDD treated patients were characterised and compared to untreated controls. The key finding of this study was the immunostimulatory attributes of LDD regimen in a range of B and T cell populations via their increased expression of TNF-a compared to untreated controls and healthy donors. The frequency of MAIT cells, however, was reduced in LDD treated patients, suggesting that these cells may not contribute to the immunostimulatory aspects, and that this regimen may impact their frequency by creating an environment which may not be compatible for MAIT cell survival. In chapter 5, expression of immuno-oncology protein markers in benign and high-grade primary and metastasised tumours were determined for alterations in hot and cold tumour regions using Digital Spatial Profiling (DSP). An increased expression of immune cell, costimulatory and inhibitory markers were apparent in high-grade tumours compared to benign. The stimulator of interferon genes (STING) marker was studied further, and its expression was also higher in high-grade tumours compared to benign, with cisplatin further enhancing its expression in ovarian cancer cell lines. There were alterations in the expression of some downstream molecules, however interferon (IFN)-b, the key cytokine produced in the activated STING pathway, was virtually non-existent. This suggests a defect in the pathway which if restored, may contribute to some of the known anti-tumour functions of the pathway. The results from these studies provide an understanding of differences in the immune profile of non-malignant and malignant ovarian cancer. These findings work together to improve our understanding of the unique TME with the aim to identify potential immune therapeutic targets for future study.
- Description: Doctor of Philosophy
Hyperbolic smoothing in nonsmooth optimization and applications
- Authors: Al Nuaimat, Alia
- Date: 2014
- Type: Text , Thesis , PhD
- Full Text:
- Description: Nonsmooth nonconvex optimization problems arise in many applications including economics, business and data mining. In these applications objective functions are not necessarily differentiable or convex. Many algorithms have been proposed over the past three decades to solve such problems. In spite of the significant growth in this field, the development of efficient algorithms for solving this kind of problem is still a challenging task. The subgradient method is one of the simplest methods developed for solving these problems. Its convergence was proved only for convex objective functions. This method does not involve any subproblems, neither for finding search directions nor for computation of step lengths, which are fixed ahead of time. Bundle methods and their various modifications are among the most efficient methods for solving nonsmooth optimization problems. These methods involve a quadratic programming subproblem to find search directions. The size of the subproblem may increase significantly with the number of variables, which makes the bundle-type methods unsuitable for large scale nonsmooth optimization problems. The implementation of bundle-type methods, which require the use of the quadratic programming solvers, is not as easy as the implementation of the subgradient methods. Therefore it is beneficial to develop algorithms for nonsmooth nonconvex optimization which are easy to implement and more efficient than the subgradient methods. In this thesis, we develop two new algorithms for solving nonsmooth nonconvex optimization problems based on the use of the hyperbolic smoothing technique and apply them to solve the pumping cost minimization problem in water distribution. Both algorithms use smoothing techniques. The first algorithm is designed for solving finite minimax problems. In order to apply the hyperbolic smoothing we reformulate the objective function in the minimax problem and study the relationship between the original minimax and reformulated problems. We also study the main properties of the hyperbolic smoothing function. Based on these results an algorithm for solving the finite minimax problem is proposed and this algorithm is implemented in GAMS. We present preliminary results of numerical experiments with well-known nonsmooth optimization test problems. We also compare the proposed algorithm with the algorithm that uses the exponential smoothing function as well as with the algorithm based on nonlinear programming reformulation of the finite minimax problem. The second nonsmooth optimization algorithm we developed was used to demonstrate how smooth optimization methods can be applied to solve general nonsmooth (nonconvex) optimization problems. In order to do so we compute subgradients from some neighborhood of the current point and define a system of linear inequalities using these subgradients. Search directions are computed by solving this system. This system is solved by reducing it to the minimization of the convex piecewise linear function over the unit ball. Then the hyperbolic smoothing function is applied to approximate this minimization problem by a sequence of smooth problems which are solved by smooth optimization methods. Such an approach allows one to apply powerful smooth optimization algorithms for solving nonsmooth optimization problems and extend smoothing techniques for solving general nonsmooth nonconvex optimization problems. The convergence of the algorithm based on this approach is studied. The proposed algorithm was implemented in Fortran 95. Preliminary results of numerical experiments are reported and the proposed algorithm is compared with an other five nonsmooth optimization algorithms. We also implement the algorithm in GAMS and compare it with GAMS solvers using results of numerical experiments.
- Description: Doctor of Philosophy
- Authors: Al Nuaimat, Alia
- Date: 2014
- Type: Text , Thesis , PhD
- Full Text:
- Description: Nonsmooth nonconvex optimization problems arise in many applications including economics, business and data mining. In these applications objective functions are not necessarily differentiable or convex. Many algorithms have been proposed over the past three decades to solve such problems. In spite of the significant growth in this field, the development of efficient algorithms for solving this kind of problem is still a challenging task. The subgradient method is one of the simplest methods developed for solving these problems. Its convergence was proved only for convex objective functions. This method does not involve any subproblems, neither for finding search directions nor for computation of step lengths, which are fixed ahead of time. Bundle methods and their various modifications are among the most efficient methods for solving nonsmooth optimization problems. These methods involve a quadratic programming subproblem to find search directions. The size of the subproblem may increase significantly with the number of variables, which makes the bundle-type methods unsuitable for large scale nonsmooth optimization problems. The implementation of bundle-type methods, which require the use of the quadratic programming solvers, is not as easy as the implementation of the subgradient methods. Therefore it is beneficial to develop algorithms for nonsmooth nonconvex optimization which are easy to implement and more efficient than the subgradient methods. In this thesis, we develop two new algorithms for solving nonsmooth nonconvex optimization problems based on the use of the hyperbolic smoothing technique and apply them to solve the pumping cost minimization problem in water distribution. Both algorithms use smoothing techniques. The first algorithm is designed for solving finite minimax problems. In order to apply the hyperbolic smoothing we reformulate the objective function in the minimax problem and study the relationship between the original minimax and reformulated problems. We also study the main properties of the hyperbolic smoothing function. Based on these results an algorithm for solving the finite minimax problem is proposed and this algorithm is implemented in GAMS. We present preliminary results of numerical experiments with well-known nonsmooth optimization test problems. We also compare the proposed algorithm with the algorithm that uses the exponential smoothing function as well as with the algorithm based on nonlinear programming reformulation of the finite minimax problem. The second nonsmooth optimization algorithm we developed was used to demonstrate how smooth optimization methods can be applied to solve general nonsmooth (nonconvex) optimization problems. In order to do so we compute subgradients from some neighborhood of the current point and define a system of linear inequalities using these subgradients. Search directions are computed by solving this system. This system is solved by reducing it to the minimization of the convex piecewise linear function over the unit ball. Then the hyperbolic smoothing function is applied to approximate this minimization problem by a sequence of smooth problems which are solved by smooth optimization methods. Such an approach allows one to apply powerful smooth optimization algorithms for solving nonsmooth optimization problems and extend smoothing techniques for solving general nonsmooth nonconvex optimization problems. The convergence of the algorithm based on this approach is studied. The proposed algorithm was implemented in Fortran 95. Preliminary results of numerical experiments are reported and the proposed algorithm is compared with an other five nonsmooth optimization algorithms. We also implement the algorithm in GAMS and compare it with GAMS solvers using results of numerical experiments.
- Description: Doctor of Philosophy
Forensic identification and detection of hidden and obfuscated malware
- Authors: Alazab, Mamoun
- Date: 2012
- Type: Text , Thesis , PhD
- Full Text:
- Description: The revolution in online criminal activities and malicious software (malware) has posed a serious challenge in malware forensics. Malicious attacks have become more organized and purposefully directed. With cybercrimes escalating to great heights in quantity as well as in sophistication and stealth, the main challenge is to detect hidden and obfuscated malware. Malware authors use a variety of obfuscation methods and specialized stealth techniques of information hiding to embed malicious code, to infect systems and to thwart any attempt to detect them, specifically with the use of commercially available anti-malware engines. This has led to the situation of zero-day attacks, where malware inflict systems even with existing security measures. The aim of this thesis is to address this situation by proposing a variety of novel digital forensic and data mining techniques to automatically detect hidden and obfuscated malware. Anti-malware engines use signature matching to detect malware where signatures are generated by human experts by disassembling the file and selecting pieces of unique code. Such signature based detection works effectively with known malware but performs poorly with hidden or unknown malware. Code obfuscation techniques, such as packers, polymorphism and metamorphism, are able to fool current detection techniques by modifying the parent code to produce offspring copies resulting in malware that has the same functionality, but with a different structure. These evasion techniques exploit the drawbacks of traditional malware detection methods, which take current malware structure and create a signature for detecting this malware in the future. However, obfuscation techniques aim to reduce vulnerability to any kind of static analysis to the determent of any reverse engineering process. Furthermore, malware can be hidden in file system slack space, inherent in NTFS file system based partitions, resulting in malware detection that even more difficult.
- Description: Doctor of Philosophy
- Authors: Alazab, Mamoun
- Date: 2012
- Type: Text , Thesis , PhD
- Full Text:
- Description: The revolution in online criminal activities and malicious software (malware) has posed a serious challenge in malware forensics. Malicious attacks have become more organized and purposefully directed. With cybercrimes escalating to great heights in quantity as well as in sophistication and stealth, the main challenge is to detect hidden and obfuscated malware. Malware authors use a variety of obfuscation methods and specialized stealth techniques of information hiding to embed malicious code, to infect systems and to thwart any attempt to detect them, specifically with the use of commercially available anti-malware engines. This has led to the situation of zero-day attacks, where malware inflict systems even with existing security measures. The aim of this thesis is to address this situation by proposing a variety of novel digital forensic and data mining techniques to automatically detect hidden and obfuscated malware. Anti-malware engines use signature matching to detect malware where signatures are generated by human experts by disassembling the file and selecting pieces of unique code. Such signature based detection works effectively with known malware but performs poorly with hidden or unknown malware. Code obfuscation techniques, such as packers, polymorphism and metamorphism, are able to fool current detection techniques by modifying the parent code to produce offspring copies resulting in malware that has the same functionality, but with a different structure. These evasion techniques exploit the drawbacks of traditional malware detection methods, which take current malware structure and create a signature for detecting this malware in the future. However, obfuscation techniques aim to reduce vulnerability to any kind of static analysis to the determent of any reverse engineering process. Furthermore, malware can be hidden in file system slack space, inherent in NTFS file system based partitions, resulting in malware detection that even more difficult.
- Description: Doctor of Philosophy
Canonical dual finite element method for solving nonconvex mechanics and topology optimization
- Authors: Ali, Elaf
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Canonical duality theory (CDT) is a newly developed, potentially powerful methodological theory which can transfer general multi-scale nonconvex/discrete problems in Rn to a unified convex dual problem in continuous space Rm with m n and without a duality gap. The associated triality theory provides extremality criteria for both global and local optimal solutions, which can be used to develop powerful algorithms for solving general nonconvex variational problems. This thesis, first, presents a detailed study of large deformation problems in 2-D structural system. Based on the canonical duality theory, a canonical dual finite element method is applied to find a global minimization to the general nonconvex optimization problem using a new primal-dual semi-definite programming algorithm. Applications are illustrated by numerical examples with different structural designs and different external loads. Next, a new methodology and algorithm for solving post buckling problems of a large deformed elastic beam is investigated. The total potential energy of this beam is a nonconvex functional, which can be used to model both pre- and post-buckling phenomena. By using the canonical dual finite element method, a new primal-dual semi-definite programming algorithm is presented, which can be used to obtain all possible post-buckled solutions. In order to verify the triality theory, mixed meshes of different dual stress interpolation are applied to obtain the closed dimensions between discretized displacement and discretized stress. Applications are illustrated by several numerical examples with different boundary conditions. We find that the global minimum solution of the nonconvex potential leads to the unbuckled state, and both of these two solutions are numerically stable. However, the local minimum solution leads to an unstable buckled state, which is very sensitive to the external load, thickness of the beam, numerical precision, and the size of finite elements. Finally, a mathematically rigorous and computationally powerful method for solving 3-D topology optimization problems is demonstrated. This method is based on CDT developed by Gao in nonconvex mechanics and global optimization. It shows that the so-called NP-hard Knapsack problem in topology optimization can be solved deterministically in polynomial-time via a canonical penalty-duality (CPD) method to obtain precise global optimal 0-1 density distribution at each volume evolution. The relation between this CPD method and Gao's pure complementary energy principle is revealed for the first time. A CPD algorithm is proposed for 3-D topology optimization of linear elastic structures. Its novelty is demonstrated by benchmark problems. Results show that without using any artificial technique, the CPD method can provide mechanically sound optimal design, also it is much more powerful than the well-known BESO and SIMP methods. Finally, computational complexity and conceptual/mathematical mistakes in topology optimization modeling and popular methods are explicitly addressed.
- Description: Doctor of Philosophy
- Description: Canonical duality theory (CDT) is a newly developed, potentially powerful method- ological theory which can transfer general multi-scale nonconvex/discrete problems in Rn to a unified convex dual problem in continuous space Rm with m
- Authors: Ali, Elaf
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Canonical duality theory (CDT) is a newly developed, potentially powerful methodological theory which can transfer general multi-scale nonconvex/discrete problems in Rn to a unified convex dual problem in continuous space Rm with m n and without a duality gap. The associated triality theory provides extremality criteria for both global and local optimal solutions, which can be used to develop powerful algorithms for solving general nonconvex variational problems. This thesis, first, presents a detailed study of large deformation problems in 2-D structural system. Based on the canonical duality theory, a canonical dual finite element method is applied to find a global minimization to the general nonconvex optimization problem using a new primal-dual semi-definite programming algorithm. Applications are illustrated by numerical examples with different structural designs and different external loads. Next, a new methodology and algorithm for solving post buckling problems of a large deformed elastic beam is investigated. The total potential energy of this beam is a nonconvex functional, which can be used to model both pre- and post-buckling phenomena. By using the canonical dual finite element method, a new primal-dual semi-definite programming algorithm is presented, which can be used to obtain all possible post-buckled solutions. In order to verify the triality theory, mixed meshes of different dual stress interpolation are applied to obtain the closed dimensions between discretized displacement and discretized stress. Applications are illustrated by several numerical examples with different boundary conditions. We find that the global minimum solution of the nonconvex potential leads to the unbuckled state, and both of these two solutions are numerically stable. However, the local minimum solution leads to an unstable buckled state, which is very sensitive to the external load, thickness of the beam, numerical precision, and the size of finite elements. Finally, a mathematically rigorous and computationally powerful method for solving 3-D topology optimization problems is demonstrated. This method is based on CDT developed by Gao in nonconvex mechanics and global optimization. It shows that the so-called NP-hard Knapsack problem in topology optimization can be solved deterministically in polynomial-time via a canonical penalty-duality (CPD) method to obtain precise global optimal 0-1 density distribution at each volume evolution. The relation between this CPD method and Gao's pure complementary energy principle is revealed for the first time. A CPD algorithm is proposed for 3-D topology optimization of linear elastic structures. Its novelty is demonstrated by benchmark problems. Results show that without using any artificial technique, the CPD method can provide mechanically sound optimal design, also it is much more powerful than the well-known BESO and SIMP methods. Finally, computational complexity and conceptual/mathematical mistakes in topology optimization modeling and popular methods are explicitly addressed.
- Description: Doctor of Philosophy
- Description: Canonical duality theory (CDT) is a newly developed, potentially powerful method- ological theory which can transfer general multi-scale nonconvex/discrete problems in Rn to a unified convex dual problem in continuous space Rm with m
Cardiovascular data analytics for real time patient monitoring
- Authors: Allami, Ragheed
- Date: 2017
- Type: Text , Thesis , PhD
- Full Text:
- Description: Improvements in wearable sensor devices make it possible to constantly monitor physiological parameters such as electrocardiograph (ECG) signals for long periods. Remote patient monitoring with wearable sensors has an important role to play in health care, particularly given the prevalence of chronic conditions such as cardiovascular disease (CVD)—one of the prominent causes of morbidity and mortality worldwide. Approximately 4.2 million Australians suffer from long-term CVD with approximately one death every 12 minutes. The assessment of ECG features, especially heart rate variability (HRV), represents a non-invasive technique which provides an indication of the autonomic nervous system (ANS) function. Conditions such as sudden cardiac death, hypertension, heart failure, myocardial infarction, ischaemia, and coronary heart disease can be detected from HRV analysis. In addition, the analysis of ECG features can also be used to diagnose many types of life-threatening arrhythmias, including ventricular fibrillation and ventricular tachycardia. Non-cardiac conditions, such as diabetes, obesity, metabolic syndrome, insulin resistance, irritable bowel syndrome, dyspepsia, anorexia nervosa, anxiety, and major depressive disorder have also been shown to be associated with HRV. The analysis of ECG features from real time ECG signals generated from wearable sensors provides distinctive challenges. The sensors that receive and process the signals have limited power, storage and processing capacity. Consequently, algorithms that process ECG signals need to be lightweight, use minimal storage resources and accurately detect abnormalities so that alarms can be raised. The existing literature details only a few algorithms which operate within the constraints of wearable sensor networks. This research presents four novel techniques that enable ECG signals to be processed within the limitations of resource constraints on devices to detect some key abnormalities in heart function. - The first technique is a novel real-time ECG data reduction algorithm, which detects and transmits only those key points that are critical for the generation of ECG features for diagnoses. - The second technique accurately predicts the five-minute HRV measure using only three minutes of data with an algorithm that executes in real-time using minimal computational resources. - The third technique introduces a real-time ECG feature recognition system that can be applied to diagnose life threatening conditions such as premature ventricular contractions (PVCs). - The fourth technique advances a classification algorithm to enhance the performance of automated ECG classification to determine arrhythmic heart beats based on noisy ECG signals. The four novel techniques are evaluated in comparison with benchmark algorithms for each task on the standard MIT-BIH Arrhythmia Database and with data generated from patients in a major hospital using Shimmer3 wearable ECG sensors. The four techniques are integrated to demonstrate that remote patient monitoring of ECG using HRV and ECG features is feasible in real time using minimal computational resources. The evaluation show that the ECG reduction algorithm is significantly better than existing algorithms that can be applied within sensor nodes, such as time-domain methods, transformation methods and compressed sensing methods. Furthermore, the proposed ECG reduction is found to be computationally less complex for resource constrained sensors and achieves higher compression ratios than existing algorithms. The prediction of a common HRV measure, the five-minute standard deviation of inter-beat variations (SDNN) and the accurate detection of PVC beats was achieved using a Count Data Model, combined with a Poisson-generated function from three-minute ECG recordings. This was achieved with minimal computational resources and was well suited to remote patient monitoring with wearable sensors. The PVC beats detection was implemented using the same count data model together with knowledge-based rules derived from clinical knowledge. A real-time cardiac patient monitoring system was implemented using an ECG sensor and smartphone to detect PVC beats within a few seconds using artificial neural networks (ANN), and it was proven to provide highly accurate results. The automated detection and classification were implemented using a new wrapper-based hybrid approach that utilized t-distributed stochastic neighbour embedding (t-SNE) in combination with self-organizing maps (SOM) to improve classification performance. The t-SNE-SOM hybrid resulted in improved sensitivity, specificity and accuracy compared to most common hybrid methods in the presence of noise. It also provided a better, more accurate identification for the presence of many types of arrhythmias from the ECG recordings, leading to a more timely diagnosis and treatment outcome.
- Description: Doctor of Philosophy
- Authors: Allami, Ragheed
- Date: 2017
- Type: Text , Thesis , PhD
- Full Text:
- Description: Improvements in wearable sensor devices make it possible to constantly monitor physiological parameters such as electrocardiograph (ECG) signals for long periods. Remote patient monitoring with wearable sensors has an important role to play in health care, particularly given the prevalence of chronic conditions such as cardiovascular disease (CVD)—one of the prominent causes of morbidity and mortality worldwide. Approximately 4.2 million Australians suffer from long-term CVD with approximately one death every 12 minutes. The assessment of ECG features, especially heart rate variability (HRV), represents a non-invasive technique which provides an indication of the autonomic nervous system (ANS) function. Conditions such as sudden cardiac death, hypertension, heart failure, myocardial infarction, ischaemia, and coronary heart disease can be detected from HRV analysis. In addition, the analysis of ECG features can also be used to diagnose many types of life-threatening arrhythmias, including ventricular fibrillation and ventricular tachycardia. Non-cardiac conditions, such as diabetes, obesity, metabolic syndrome, insulin resistance, irritable bowel syndrome, dyspepsia, anorexia nervosa, anxiety, and major depressive disorder have also been shown to be associated with HRV. The analysis of ECG features from real time ECG signals generated from wearable sensors provides distinctive challenges. The sensors that receive and process the signals have limited power, storage and processing capacity. Consequently, algorithms that process ECG signals need to be lightweight, use minimal storage resources and accurately detect abnormalities so that alarms can be raised. The existing literature details only a few algorithms which operate within the constraints of wearable sensor networks. This research presents four novel techniques that enable ECG signals to be processed within the limitations of resource constraints on devices to detect some key abnormalities in heart function. - The first technique is a novel real-time ECG data reduction algorithm, which detects and transmits only those key points that are critical for the generation of ECG features for diagnoses. - The second technique accurately predicts the five-minute HRV measure using only three minutes of data with an algorithm that executes in real-time using minimal computational resources. - The third technique introduces a real-time ECG feature recognition system that can be applied to diagnose life threatening conditions such as premature ventricular contractions (PVCs). - The fourth technique advances a classification algorithm to enhance the performance of automated ECG classification to determine arrhythmic heart beats based on noisy ECG signals. The four novel techniques are evaluated in comparison with benchmark algorithms for each task on the standard MIT-BIH Arrhythmia Database and with data generated from patients in a major hospital using Shimmer3 wearable ECG sensors. The four techniques are integrated to demonstrate that remote patient monitoring of ECG using HRV and ECG features is feasible in real time using minimal computational resources. The evaluation show that the ECG reduction algorithm is significantly better than existing algorithms that can be applied within sensor nodes, such as time-domain methods, transformation methods and compressed sensing methods. Furthermore, the proposed ECG reduction is found to be computationally less complex for resource constrained sensors and achieves higher compression ratios than existing algorithms. The prediction of a common HRV measure, the five-minute standard deviation of inter-beat variations (SDNN) and the accurate detection of PVC beats was achieved using a Count Data Model, combined with a Poisson-generated function from three-minute ECG recordings. This was achieved with minimal computational resources and was well suited to remote patient monitoring with wearable sensors. The PVC beats detection was implemented using the same count data model together with knowledge-based rules derived from clinical knowledge. A real-time cardiac patient monitoring system was implemented using an ECG sensor and smartphone to detect PVC beats within a few seconds using artificial neural networks (ANN), and it was proven to provide highly accurate results. The automated detection and classification were implemented using a new wrapper-based hybrid approach that utilized t-distributed stochastic neighbour embedding (t-SNE) in combination with self-organizing maps (SOM) to improve classification performance. The t-SNE-SOM hybrid resulted in improved sensitivity, specificity and accuracy compared to most common hybrid methods in the presence of noise. It also provided a better, more accurate identification for the presence of many types of arrhythmias from the ECG recordings, leading to a more timely diagnosis and treatment outcome.
- Description: Doctor of Philosophy
Australian nursing students’ perceptions of being a nurse : a mixed methods study
- Authors: Allen, Louise
- Date: 2023
- Type: Text , Thesis , PhD
- Full Text:
- Description: Background Nursing students often enter nursing programs with idealistic, altruistic perceptions of what it means to be a nurse. Over time, however, many discover that these perceptions are naïve and unrealistic. Nursing is a demanding profession that requires knowledge, skill and emotional resilience in often demanding and challenging situations that can influence emotional intelligence. Therefore, an early and realistic understanding of professional requirements may reduce transition shock and attrition rates. Aim The aim of this thesis is to explore Bachelor of Nursing (BN) students’ perceptions of being a nurse in Australia. Methods This study used an explanatory sequential mixed methods design. The 34-item Perceptions of a Registered Nurse (PRN) survey tool was developed using a Nominal Group Technique and validated with a sample of 797 participants across three universities and states. Descriptive and inferential statistical analysis was incorporated as applicable. In addition, online semi-structured interviews with 23 nursing students (n = 23) explored their perceptions of a nurse in detail, with a thematic analysis of outcomes. Results Demographic variables influenced perceptions. There were significant differences in item-by-item perceptions related to ‘primary language spoken at home’ (13/34 items; p < .04), ‘university of study’ (10/34 items; p
- Description: Doctor of Philosophy
- Authors: Allen, Louise
- Date: 2023
- Type: Text , Thesis , PhD
- Full Text:
- Description: Background Nursing students often enter nursing programs with idealistic, altruistic perceptions of what it means to be a nurse. Over time, however, many discover that these perceptions are naïve and unrealistic. Nursing is a demanding profession that requires knowledge, skill and emotional resilience in often demanding and challenging situations that can influence emotional intelligence. Therefore, an early and realistic understanding of professional requirements may reduce transition shock and attrition rates. Aim The aim of this thesis is to explore Bachelor of Nursing (BN) students’ perceptions of being a nurse in Australia. Methods This study used an explanatory sequential mixed methods design. The 34-item Perceptions of a Registered Nurse (PRN) survey tool was developed using a Nominal Group Technique and validated with a sample of 797 participants across three universities and states. Descriptive and inferential statistical analysis was incorporated as applicable. In addition, online semi-structured interviews with 23 nursing students (n = 23) explored their perceptions of a nurse in detail, with a thematic analysis of outcomes. Results Demographic variables influenced perceptions. There were significant differences in item-by-item perceptions related to ‘primary language spoken at home’ (13/34 items; p < .04), ‘university of study’ (10/34 items; p
- Description: Doctor of Philosophy
The competing discourses of workplace health
- Authors: Allender, Steven
- Date: 2001
- Type: Text , Thesis , PhD
- Full Text:
- Description: "This study provides a postcritical analysis of the discourses on workplace health, using data gathered with information technology company Labyrinth Computing."
- Description: Doctor of Philosophy
- Authors: Allender, Steven
- Date: 2001
- Type: Text , Thesis , PhD
- Full Text:
- Description: "This study provides a postcritical analysis of the discourses on workplace health, using data gathered with information technology company Labyrinth Computing."
- Description: Doctor of Philosophy
An analysis of autonomic nervous system fuctioning in panic disorder and its relation to negative affect / Marles E. Alvarenga
- Authors: Alvarenga, Marlies
- Date: 2002
- Type: Text , Thesis , PhD
- Full Text:
- Description: "The present studies investigated the issue of potential explanatory mechanisms for the observed association between panic disorder (PD) and the development of cardiovascular disease (CVD). Specifically, this research aimed to elucidate more clearly the contribution of psychological variables. physical processes and social relations to the onset of cardiopathology."
- Description: Doctor of Clinical Psychology
- Authors: Alvarenga, Marlies
- Date: 2002
- Type: Text , Thesis , PhD
- Full Text:
- Description: "The present studies investigated the issue of potential explanatory mechanisms for the observed association between panic disorder (PD) and the development of cardiovascular disease (CVD). Specifically, this research aimed to elucidate more clearly the contribution of psychological variables. physical processes and social relations to the onset of cardiopathology."
- Description: Doctor of Clinical Psychology
Managing risk and enhancing corporate sustainability in the Australian extractive sector : An exploratory study of leading mining and oil & gas firms in Australia
- Authors: Andeobu, Lynda
- Date: 2016
- Type: Text , Thesis , PhD
- Full Text:
- Description: Risk is an unavoidable issue in most activities of life, including business. Risk-management is increasingly a hot-button issue for stakeholders and the general public. As such, it is of rising importance in the high-risk extractive industries of mining and oil & gas. Specifically, risk-management can help firms reduce business failure-rates and enhance corporate sustainability. However, the integration of risk-management and corporate sustainability within planning, financing, and operations remains a key challenge for the sector. This research seeks to fill this gap by investigating and evaluating the current use of risk-management by extractive-sector firms to add value to stakeholders. Given that risk- management and its impact on corporate sustainability is enormous, this study will provide useful insights into the risk-management practices undertaken by extractive-sector firms in Australia and how cost-effective risk-management practices contribute to the overall enhancement of financial performance, stakeholder value and corporate sustainability of those firms. This study, after drawing data from Australia’s top 10 mining/metals firms and top 10 energy/utilities firms, uses: i) Questionnaires to give a background/context for the study, and ii) Interviews to further probe issues raised and gain a deeper understanding. The analysis in this study found that risk-management practices are: i) Perceived by management practices to contribute significantly to financial performance, stakeholder value and corporate sustainability of their firms ii) Very similar across mining firms and those in oil & gas, and iii) Too limited in application in the extractive-sector and should be extended beyond traditional hazards. Overall, it was found that risk-management systems appear to be comparable across Australia’s large mining firms and oil & gas firms. However, at a detailed level, these basic systems and structures of risk-management are adjusted and adapted to meet specific needs, corporate strategies, organisational objectives and environmental pressures. NOTE: At the request of the author, Chapters 2-12 and Appendix 7 have been removed.
- Description: Doctor of Philosophy
- Authors: Andeobu, Lynda
- Date: 2016
- Type: Text , Thesis , PhD
- Full Text:
- Description: Risk is an unavoidable issue in most activities of life, including business. Risk-management is increasingly a hot-button issue for stakeholders and the general public. As such, it is of rising importance in the high-risk extractive industries of mining and oil & gas. Specifically, risk-management can help firms reduce business failure-rates and enhance corporate sustainability. However, the integration of risk-management and corporate sustainability within planning, financing, and operations remains a key challenge for the sector. This research seeks to fill this gap by investigating and evaluating the current use of risk-management by extractive-sector firms to add value to stakeholders. Given that risk- management and its impact on corporate sustainability is enormous, this study will provide useful insights into the risk-management practices undertaken by extractive-sector firms in Australia and how cost-effective risk-management practices contribute to the overall enhancement of financial performance, stakeholder value and corporate sustainability of those firms. This study, after drawing data from Australia’s top 10 mining/metals firms and top 10 energy/utilities firms, uses: i) Questionnaires to give a background/context for the study, and ii) Interviews to further probe issues raised and gain a deeper understanding. The analysis in this study found that risk-management practices are: i) Perceived by management practices to contribute significantly to financial performance, stakeholder value and corporate sustainability of their firms ii) Very similar across mining firms and those in oil & gas, and iii) Too limited in application in the extractive-sector and should be extended beyond traditional hazards. Overall, it was found that risk-management systems appear to be comparable across Australia’s large mining firms and oil & gas firms. However, at a detailed level, these basic systems and structures of risk-management are adjusted and adapted to meet specific needs, corporate strategies, organisational objectives and environmental pressures. NOTE: At the request of the author, Chapters 2-12 and Appendix 7 have been removed.
- Description: Doctor of Philosophy
An evaluation of low and high intensity digital mental health treatment models for anxiety and depression : an adaptive treatment randomized clinical trial
- Authors: Andrews, Brooke
- Date: 2023
- Type: Text , Thesis , PhD
- Full Text:
- Description: Doctor of Philsophy
- Authors: Andrews, Brooke
- Date: 2023
- Type: Text , Thesis , PhD
- Full Text:
- Description: Doctor of Philsophy
Program behaviour modelling with flexible logical entity abstraction
- Authors: Andrews, David
- Date: 2006
- Type: Text , Thesis , PhD
- Full Text:
- Description: "This study extends the use of abstration in program behaviour modelling, and provides a flexible abstraction technique that allows modelling in terms of the logical abstract concepts with which a program operates. This technique is called a Logical Entity Abstracted Program Behaviour Modelling (LEAPBM)."--leaf [ii]
- Description: Doctor of Philosophy
- Authors: Andrews, David
- Date: 2006
- Type: Text , Thesis , PhD
- Full Text:
- Description: "This study extends the use of abstration in program behaviour modelling, and provides a flexible abstraction technique that allows modelling in terms of the logical abstract concepts with which a program operates. This technique is called a Logical Entity Abstracted Program Behaviour Modelling (LEAPBM)."--leaf [ii]
- Description: Doctor of Philosophy
A longitudinal study of trauma, social and personality factors as predictors of post-traumatic stress symptom severity in student paramedics
- Authors: Armstrong, Kim Maree
- Date: 2008
- Type: Text , Thesis , PhD
- Full Text:
- Description: Previous research suggests student paramedics are among the professionals at highest risk of post-traumatic stress disorder (PTSD). However, little research has been conducted examining duty-related post-traumatic stress symptoms (PTSS) and clinical levels of PTSD in this poplulation. The current study of 36 student paramedics undertaking university or job-based training is the first longitudinal investigation of PTSS and PTSD in this group.
- Description: Professional Doctorate of Psychology (Clinical)
- Authors: Armstrong, Kim Maree
- Date: 2008
- Type: Text , Thesis , PhD
- Full Text:
- Description: Previous research suggests student paramedics are among the professionals at highest risk of post-traumatic stress disorder (PTSD). However, little research has been conducted examining duty-related post-traumatic stress symptoms (PTSS) and clinical levels of PTSD in this poplulation. The current study of 36 student paramedics undertaking university or job-based training is the first longitudinal investigation of PTSS and PTSD in this group.
- Description: Professional Doctorate of Psychology (Clinical)
Algae-based models to configure consumptive flows for ecological benefit in the highly regulated MacKenzie River, south-east Australia
- Authors: Atazadeh, Ehsan
- Date: 2017
- Type: Text , Thesis , PhD
- Full Text:
- Description: Many river ecosystems, especially those in arid and semi-arid, are experiencing severe stress due to the increasing demands on the ecosystem services they provide, coupled with anthropogenic catchment impacts and factors associated with climate change and weather extremes. The flow regime of the Mackenzie River was substantially modified since the construction of a water supply reservoir on its upper reach in 1887. Water is now regulated at several locations downstream of the reservoir, creating a substantially modified flow regime, impacting key environmental values of the river. The river receives an environmental flow allocation and the river channel is used to transfer water dedicated for consumptive use. Water Quality and algal monitoring formed the basis of models that were developed evaluate the ecological condition of this working river under base flow and before, during and after freshes that deliver water to users. Samples of diatoms, soft algae and measurements of water quality were analysed at ten sampling sites for three years (between February 2012 and November 2014) along the MacKenzie River in different seasons and under different flow regimes to understand the spatial and temporal variation in the relationship between algal communities and water quality, and so stream condition. Baseline information on algal communities and water quality was collected during base flow conditions, while experiments on the effect of water releases on algal communities were based on flow regime variations (manipulated flow regimes), specifically on the algae community structure, water quality and ecosystem function. These comprised cease to flow (0 ML/day), low flows (10-15 ML/day), freshes (35-40 ML/day) and high flow (55ML/day) conditions. Physical and chemical characteristics of water, including pH, temperature, turbidity, electrical conductivity, dissolved oxygen, total nitrogen, phosphorus and cations and anions were measured. Biological properties of the algal periphyton communities, including dry mass, ash-free dry mass, chlorophyll-a concentration and species composition, were also measured. Furthermore, the DSIAR (Diatom Species Index for Australian Rivers) score was calculated to classify the condition of the waterway. The results showed the algal species composition changed under different flow regimes along the river. The sensitivity of diatoms to changes in water quality and flow rates deemed them useful indicators of river condition. The results indicated that flows tended to improve DSIAR scores and diatoms versus green algae and cyanobacteria biomass measures in the mid and lower reaches. The biological properties of the algal periphyton communities, and the species composition, varied between sites under different flow regimes. The accumulation of dry mass (not ash-free) decreased downstream during freshes, however the accumulation of AFDM (ash-free dry mass) gradually increased downstream. The results showed that the concentration of chlorophyll-a decreased downstream under water release events. The Pearson’s correlation matrix revealed flow regimes had a significant influence on the water chemistry characteristics and biological properties. The principal component analysis (PCA) illustrated that upstream species of algae were associated with low pH and temperature and higher DO. In contrast downstream species were associated with higher turbidity, TSS, conductivity, TN, and TDS. The correspondence analysis (CA) and detrended correspondence analysis (DCA) showed a split between algal assemblages during water release events in comparison with before and after water release. The canonical correspondence analysis (CCA) identified five significant environmental variables including pH, TSS, Turbidity, TN and TP explaining algal assemblage and structure along the river. The collected data were used to develop ecological response models based on algae communities living under different flow regimes in the MacKenzie River. The algae-based models across a hydraulic gradient may be useful in water management efforts to find sustainable solutions in the river by balancing environmental and human values. The empirical data and models showed the lower reaches of the river to be in poor condition under low flows, but this condition improved under flows of 35 ML/day, as indicated by the reduction in green algae and cyanobacteria and improvement in DSIAR scores. The results are presented to tailor discharge and duration of the river flows by amalgamation of consumptive and environmental flows to improve the condition of the stream thereby supplementing the flows dedicated to environmental outcomes. Ultimately the findings can be used by management to configure consumptive flows to enhance the for ecological condition of the MacKenzie River.
- Description: Doctor of Philosophy
- Authors: Atazadeh, Ehsan
- Date: 2017
- Type: Text , Thesis , PhD
- Full Text:
- Description: Many river ecosystems, especially those in arid and semi-arid, are experiencing severe stress due to the increasing demands on the ecosystem services they provide, coupled with anthropogenic catchment impacts and factors associated with climate change and weather extremes. The flow regime of the Mackenzie River was substantially modified since the construction of a water supply reservoir on its upper reach in 1887. Water is now regulated at several locations downstream of the reservoir, creating a substantially modified flow regime, impacting key environmental values of the river. The river receives an environmental flow allocation and the river channel is used to transfer water dedicated for consumptive use. Water Quality and algal monitoring formed the basis of models that were developed evaluate the ecological condition of this working river under base flow and before, during and after freshes that deliver water to users. Samples of diatoms, soft algae and measurements of water quality were analysed at ten sampling sites for three years (between February 2012 and November 2014) along the MacKenzie River in different seasons and under different flow regimes to understand the spatial and temporal variation in the relationship between algal communities and water quality, and so stream condition. Baseline information on algal communities and water quality was collected during base flow conditions, while experiments on the effect of water releases on algal communities were based on flow regime variations (manipulated flow regimes), specifically on the algae community structure, water quality and ecosystem function. These comprised cease to flow (0 ML/day), low flows (10-15 ML/day), freshes (35-40 ML/day) and high flow (55ML/day) conditions. Physical and chemical characteristics of water, including pH, temperature, turbidity, electrical conductivity, dissolved oxygen, total nitrogen, phosphorus and cations and anions were measured. Biological properties of the algal periphyton communities, including dry mass, ash-free dry mass, chlorophyll-a concentration and species composition, were also measured. Furthermore, the DSIAR (Diatom Species Index for Australian Rivers) score was calculated to classify the condition of the waterway. The results showed the algal species composition changed under different flow regimes along the river. The sensitivity of diatoms to changes in water quality and flow rates deemed them useful indicators of river condition. The results indicated that flows tended to improve DSIAR scores and diatoms versus green algae and cyanobacteria biomass measures in the mid and lower reaches. The biological properties of the algal periphyton communities, and the species composition, varied between sites under different flow regimes. The accumulation of dry mass (not ash-free) decreased downstream during freshes, however the accumulation of AFDM (ash-free dry mass) gradually increased downstream. The results showed that the concentration of chlorophyll-a decreased downstream under water release events. The Pearson’s correlation matrix revealed flow regimes had a significant influence on the water chemistry characteristics and biological properties. The principal component analysis (PCA) illustrated that upstream species of algae were associated with low pH and temperature and higher DO. In contrast downstream species were associated with higher turbidity, TSS, conductivity, TN, and TDS. The correspondence analysis (CA) and detrended correspondence analysis (DCA) showed a split between algal assemblages during water release events in comparison with before and after water release. The canonical correspondence analysis (CCA) identified five significant environmental variables including pH, TSS, Turbidity, TN and TP explaining algal assemblage and structure along the river. The collected data were used to develop ecological response models based on algae communities living under different flow regimes in the MacKenzie River. The algae-based models across a hydraulic gradient may be useful in water management efforts to find sustainable solutions in the river by balancing environmental and human values. The empirical data and models showed the lower reaches of the river to be in poor condition under low flows, but this condition improved under flows of 35 ML/day, as indicated by the reduction in green algae and cyanobacteria and improvement in DSIAR scores. The results are presented to tailor discharge and duration of the river flows by amalgamation of consumptive and environmental flows to improve the condition of the stream thereby supplementing the flows dedicated to environmental outcomes. Ultimately the findings can be used by management to configure consumptive flows to enhance the for ecological condition of the MacKenzie River.
- Description: Doctor of Philosophy
The literacy practices of Kunibídji children : Text, technology and transformation
- Authors: Auld, Glenn
- Date: 2005
- Type: Text , Thesis , PhD
- Full Text:
- Description: Members of the Kunibídji community are the traditional owners of the lands and seas around Maningrida, a remote community in Arnhem Land in Northern Australia. Kunibídji children speak Ndjébbana as their first language and learn to speak English as a third or fourth language at school. Underpinning this study is a belief that the children have the right to speak their own language and access texts in their own language at home. [...] This study investigated the literacy practices that approximately fifty Kunibídji children enacted in the literacy events with the Ndjébbana talking books. [...] This study found that Kunibídji children had a desire to access the Ndjébbana talking books, a will to participate in the literacy events and the capacity to be critical about these literacy events at home.
- Description: Doctor of Philosophy
- Authors: Auld, Glenn
- Date: 2005
- Type: Text , Thesis , PhD
- Full Text:
- Description: Members of the Kunibídji community are the traditional owners of the lands and seas around Maningrida, a remote community in Arnhem Land in Northern Australia. Kunibídji children speak Ndjébbana as their first language and learn to speak English as a third or fourth language at school. Underpinning this study is a belief that the children have the right to speak their own language and access texts in their own language at home. [...] This study investigated the literacy practices that approximately fifty Kunibídji children enacted in the literacy events with the Ndjébbana talking books. [...] This study found that Kunibídji children had a desire to access the Ndjébbana talking books, a will to participate in the literacy events and the capacity to be critical about these literacy events at home.
- Description: Doctor of Philosophy
Access and engagement of First Nations women in maternal and child health services
- Authors: Austin, Catherine
- Date: 2023
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis explores and describes the engagement of First Nations women, with children from birth to five years of age, with Maternal and Child Health (MCH) services in Victoria, Australia. Identification of the factors that facilitate, support or hinder these women’s engagement with MCH services could strengthen the model of care to effectively engage First Nations women with these services. Access in the early years of a child’s life to integrated, effective, community-based services is a well-established predictor of a child’s successful transition to school and their lifelong education and employment outcomes. Such access is crucial in a child’s first 2,000 days (the period from conception to the child’s fifth year), which forms the foundation for a child’s lifetime development and health. Prior evaluative studies have shown that participation in MCH services in Victoria improves the health outcomes for children and families, particularly First Nations families. However, First Nations women and their children in Victoria show poorer health outcomes and lower participation in MCH services compared to non-Indigenous persons; this suggests a need to improve the current Victorian MCH service model. This thesis contributes recommendations for such improvements. The literature review (Chapter 2) identified the absence of a synthesis of qualitative studies of models of care to help guide MCH practice and innovation for all families, especially those at risk of child abuse and neglect. To address this gap, a three-phase qualitative study was conducted in the Glenelg Shire, Victoria, Australia, using narrative inquiry integrated with the Indigenous philosophy ‘Dadirri’. ‘Dadirri’, which emphasises deep and respectful listening, guided the development of the research design; this methodology assisted in understanding Indigenous culture and its sensitivities, building trust with the First Nations peoples involved in the studies, developing open-ended and conversational dialogue, and building respectful relationships. This method enabled First Nations women’s voices to be heard and the collection of rich data based on participants’ perspectives of and experiences with MCH services in Victoria. Study One (Chapter 4) recruited First Nations women residing in the Glenelg Shire, with at least one child aged birth to five years, to explore their perceptions and experiences of MCH services and barriers to accessing and engaging with MCH services. Study Two (Chapter 5) compared Study One data with accounts from MCH nurses working in Glenelg Shire. Study Three (Chapter 6) reviewed a piloting of the Early Assessment Referral Links (EARL) concept (developed by the researcher) that aims to improve First Nations women and their children’s access to and engagement with MCH services. EARL involved the core principles of narrative inquiry integrated with ‘Dadirri’. Study One and Two found that enabling factors for access and engagement include interventions that are culturally sensitive and effective; recognise the social determinates of health (SDOH) and social and emotional wellbeing; are timely, appropriate, culturally strong, flexible, holistic and community-based; support continuity of care and communication; and encourage early identification of risk, particularly of family violence (FV), and further assessment, intervention, referral and support in the child’s first 2,000 days. Barriers to access and engagement include an ineffective service model built on mistrust, poor communication due to cultural differences between client and provider (particularly around identification and disclosure of woman’s risk of FV), lack of continuity of care between services, limited flexibility of service delivery to suit individual needs, and a service model that does not recognise the importance of the SDOH and social and emotional wellbeing. Study Three results showed that participation of First Nations families in MCH services was consistently above the state average during the pilot period, and several First Nations families were referred to EARL stakeholders and other health professionals during the pilot. Further, there were increases in First Nations children being breastfed, fully immunised and attending Early Start Kindergarten, and identification of First Nations children at risk of abuse or neglect improved (with a significant increase in referrals for FV and child protection and significant decrease in episodes of out-of-home care). This thesis’s findings can support policy development. This research shows that timely, effective, holistic engagement with First Nations women in their child’s first 2,000 days, that respects their culture and facilitates genuine partnerships built on co-design and shared decision-making with the Indigenous community, needs to be an essential part of the MCH service model. Additionally, this thesis recommends adopting a strengths-based approach that respects First Nations peoples’ child-rearing practices and culture, and providing necessary training to MCH nurses who work with First Nations families. Keywords: child family health, continuity of care, First Nations women
- Description: Doctor of Philosophy
- Authors: Austin, Catherine
- Date: 2023
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis explores and describes the engagement of First Nations women, with children from birth to five years of age, with Maternal and Child Health (MCH) services in Victoria, Australia. Identification of the factors that facilitate, support or hinder these women’s engagement with MCH services could strengthen the model of care to effectively engage First Nations women with these services. Access in the early years of a child’s life to integrated, effective, community-based services is a well-established predictor of a child’s successful transition to school and their lifelong education and employment outcomes. Such access is crucial in a child’s first 2,000 days (the period from conception to the child’s fifth year), which forms the foundation for a child’s lifetime development and health. Prior evaluative studies have shown that participation in MCH services in Victoria improves the health outcomes for children and families, particularly First Nations families. However, First Nations women and their children in Victoria show poorer health outcomes and lower participation in MCH services compared to non-Indigenous persons; this suggests a need to improve the current Victorian MCH service model. This thesis contributes recommendations for such improvements. The literature review (Chapter 2) identified the absence of a synthesis of qualitative studies of models of care to help guide MCH practice and innovation for all families, especially those at risk of child abuse and neglect. To address this gap, a three-phase qualitative study was conducted in the Glenelg Shire, Victoria, Australia, using narrative inquiry integrated with the Indigenous philosophy ‘Dadirri’. ‘Dadirri’, which emphasises deep and respectful listening, guided the development of the research design; this methodology assisted in understanding Indigenous culture and its sensitivities, building trust with the First Nations peoples involved in the studies, developing open-ended and conversational dialogue, and building respectful relationships. This method enabled First Nations women’s voices to be heard and the collection of rich data based on participants’ perspectives of and experiences with MCH services in Victoria. Study One (Chapter 4) recruited First Nations women residing in the Glenelg Shire, with at least one child aged birth to five years, to explore their perceptions and experiences of MCH services and barriers to accessing and engaging with MCH services. Study Two (Chapter 5) compared Study One data with accounts from MCH nurses working in Glenelg Shire. Study Three (Chapter 6) reviewed a piloting of the Early Assessment Referral Links (EARL) concept (developed by the researcher) that aims to improve First Nations women and their children’s access to and engagement with MCH services. EARL involved the core principles of narrative inquiry integrated with ‘Dadirri’. Study One and Two found that enabling factors for access and engagement include interventions that are culturally sensitive and effective; recognise the social determinates of health (SDOH) and social and emotional wellbeing; are timely, appropriate, culturally strong, flexible, holistic and community-based; support continuity of care and communication; and encourage early identification of risk, particularly of family violence (FV), and further assessment, intervention, referral and support in the child’s first 2,000 days. Barriers to access and engagement include an ineffective service model built on mistrust, poor communication due to cultural differences between client and provider (particularly around identification and disclosure of woman’s risk of FV), lack of continuity of care between services, limited flexibility of service delivery to suit individual needs, and a service model that does not recognise the importance of the SDOH and social and emotional wellbeing. Study Three results showed that participation of First Nations families in MCH services was consistently above the state average during the pilot period, and several First Nations families were referred to EARL stakeholders and other health professionals during the pilot. Further, there were increases in First Nations children being breastfed, fully immunised and attending Early Start Kindergarten, and identification of First Nations children at risk of abuse or neglect improved (with a significant increase in referrals for FV and child protection and significant decrease in episodes of out-of-home care). This thesis’s findings can support policy development. This research shows that timely, effective, holistic engagement with First Nations women in their child’s first 2,000 days, that respects their culture and facilitates genuine partnerships built on co-design and shared decision-making with the Indigenous community, needs to be an essential part of the MCH service model. Additionally, this thesis recommends adopting a strengths-based approach that respects First Nations peoples’ child-rearing practices and culture, and providing necessary training to MCH nurses who work with First Nations families. Keywords: child family health, continuity of care, First Nations women
- Description: Doctor of Philosophy
Consultation and organisational maturity in the Victorian construction industry
- Authors: Ayers, Gerard
- Date: 2012
- Type: Text , Thesis , PhD
- Full Text:
- Description: Consultation is generally acknowledged both in Australia and internationally, as being essential if high levels of occupational health and safety (OHS) are to be achieved and maintained. In Victoria, such is the recognition of the important role that consultation plays in OHS, that it is mandated under the Victorian OHS regulatory framework. Indeed, all Australian OHS statutes now make provision, to varying degrees, for consultation to occur when dealing with OHS matters. This is principally conducted through OHS representatives and OHS committees. However, there is a growing body of opinion which raises concerns over whether such legislative provisions that provide for OHS consultation, is sufficiently adequate to ensure that the consultation is both meaningful and effective in terms of OHS outcomes. If this is the case, what might be missing or lacking from the consultation process, especially in hazardous and dangerous industries where OHS success would appear to be imperative? The Victorian construction industry, like the construction industry in general, is acknowledged for its dangerous and hazardous nature. It has a large transitory workforce with little permanent job security and often suffers from a multifarious and disjointed work organisation structure. Such features tend to work against an environment that openly recognises and encourages meaningful and effective consultation. These conditions also tend to confound the development of any kind of social and positive learning and communicative culture within the industry, leading to an underutilization of the knowledge and skill contained within the workforce. As well as failing to bring to fruition the full participation of workers in the management of OHS, the underutilization of knowledge and skill is potentially one of the largest hidden costs that an organisation may incur. The notion of organisational and cultural maturity is acknowledged both internationally and in Australia as a useful concept that can assist organisations in achieving higher standards and levels of OHS. This is especially so in high risk and hazardous industries such as the petrochemical, oil refinery and aviation industries. However, organisational and cultural maturity is arguably a relatively new and under-researched construct in the Victorian building and construction industry, while the concept of consultation within both the industry and the organisational maturity paradigm has not yet been sufficiently explored. The role that moral and ethical principles play in consultation is now beginning to emerge and gain wider recognition within the literature. This research project set out to examine how some of these principles were applied by senior site managers and OHS representatives of five Victorian construction companies during OHS consultation at five different constructions sites, and whether this consultation could be considered to be meaningful and effective. The companies who participated in this project were each allocated a level of organisational maturity, dependent upon how they managed various aspects of their business operations in terms of OHS. Senior managers and OHS representatives were chosen as participants in the research because they are generally acknowledged as the critical vectors in the sharing and transferring of knowledge and skill at the workplace. The data from this research suggest that regardless of the level of organisational maturity each organisation was deemed to have reached, and no matter how the individual participants applied the particular moral and ethical principles used during this research, the OHS consultation that took place on the different construction sites was limited to, and focused primarily on, everyday operational and execution aspects of the job, rather than more strategic and longer term OHS issues. The practical implications of this research are that if OHS consultation between senior managers and OHS representatives can be conducted in such a way as to openly and unambiguously recognise and apply particular moral and ethical principles, and if consultation is allowed to focus on more strategic and longer term OHS and organisational aspects of a construction project, this may yield more benefits, in terms of OHS outcomes, for all industry participants.
- Authors: Ayers, Gerard
- Date: 2012
- Type: Text , Thesis , PhD
- Full Text:
- Description: Consultation is generally acknowledged both in Australia and internationally, as being essential if high levels of occupational health and safety (OHS) are to be achieved and maintained. In Victoria, such is the recognition of the important role that consultation plays in OHS, that it is mandated under the Victorian OHS regulatory framework. Indeed, all Australian OHS statutes now make provision, to varying degrees, for consultation to occur when dealing with OHS matters. This is principally conducted through OHS representatives and OHS committees. However, there is a growing body of opinion which raises concerns over whether such legislative provisions that provide for OHS consultation, is sufficiently adequate to ensure that the consultation is both meaningful and effective in terms of OHS outcomes. If this is the case, what might be missing or lacking from the consultation process, especially in hazardous and dangerous industries where OHS success would appear to be imperative? The Victorian construction industry, like the construction industry in general, is acknowledged for its dangerous and hazardous nature. It has a large transitory workforce with little permanent job security and often suffers from a multifarious and disjointed work organisation structure. Such features tend to work against an environment that openly recognises and encourages meaningful and effective consultation. These conditions also tend to confound the development of any kind of social and positive learning and communicative culture within the industry, leading to an underutilization of the knowledge and skill contained within the workforce. As well as failing to bring to fruition the full participation of workers in the management of OHS, the underutilization of knowledge and skill is potentially one of the largest hidden costs that an organisation may incur. The notion of organisational and cultural maturity is acknowledged both internationally and in Australia as a useful concept that can assist organisations in achieving higher standards and levels of OHS. This is especially so in high risk and hazardous industries such as the petrochemical, oil refinery and aviation industries. However, organisational and cultural maturity is arguably a relatively new and under-researched construct in the Victorian building and construction industry, while the concept of consultation within both the industry and the organisational maturity paradigm has not yet been sufficiently explored. The role that moral and ethical principles play in consultation is now beginning to emerge and gain wider recognition within the literature. This research project set out to examine how some of these principles were applied by senior site managers and OHS representatives of five Victorian construction companies during OHS consultation at five different constructions sites, and whether this consultation could be considered to be meaningful and effective. The companies who participated in this project were each allocated a level of organisational maturity, dependent upon how they managed various aspects of their business operations in terms of OHS. Senior managers and OHS representatives were chosen as participants in the research because they are generally acknowledged as the critical vectors in the sharing and transferring of knowledge and skill at the workplace. The data from this research suggest that regardless of the level of organisational maturity each organisation was deemed to have reached, and no matter how the individual participants applied the particular moral and ethical principles used during this research, the OHS consultation that took place on the different construction sites was limited to, and focused primarily on, everyday operational and execution aspects of the job, rather than more strategic and longer term OHS issues. The practical implications of this research are that if OHS consultation between senior managers and OHS representatives can be conducted in such a way as to openly and unambiguously recognise and apply particular moral and ethical principles, and if consultation is allowed to focus on more strategic and longer term OHS and organisational aspects of a construction project, this may yield more benefits, in terms of OHS outcomes, for all industry participants.