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
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
A study of visitor satisfaction in tourism enterprises
- Authors: Ali, Shameen
- Date: 2012
- Type: Text , Thesis , DBA
- Full Text:
- Description: Satisfying customers is fundamental to the marketing concept and has long been recognised as important, firstly in the economic discipline and subsequently in marketing and in business generally. In a competitive marketplace customer satisfaction is closely linked to the ability of the organisation to deliver quality. Therefore, organisations rely on the feedback received from customers about how satisfied or dissatisfied they are with product and service provision and their perceptions of the value received. The study examines the various product and service attributes that contribute to visitor satisfaction and experience, and evaluates the role of price-value perceptions and behavioural intentions. This examination was undertaken by the study of three tourism enterprises operating in the heritage tourism area. These included Sovereign Hill, which is an historic goldfields township; Brambuk, which is an indigenous cultural centre located in the Grampians in Western Victoria; and Werribee Mansion, which depicts the life of a wealthy farming family in the early periods in Victoria. This study has provided insight into the understanding of visitor satisfaction in tourism enterprises by evaluating the relationship between overall satisfaction and dissatisfaction and how these influence revisit and recommending behaviour, as well as the influence of price-value perceptions on satisfaction, experience and enjoyment. The study shows that price-value dissatisfaction impacts negatively on the willingness of visitors to recommend a tourism venue to others and that price dissatisfaction tends to impact negatively on satisfaction. The results provide some insight into what contributes to tourist satisfaction, enjoyment and experience. The findings are expected to assist strategic and operational managers in their quest for continued quality enhancement and the provision and renewal of tourism products and services. It is expected that the findings will provide some guidance to managers, tourism operators, marketers and researchers alike in developing well informed data and analyses that are the key to strategic and competitive advantage.
- Description: Doctor of Business Adminstration
- Authors: Ali, Shameen
- Date: 2012
- Type: Text , Thesis , DBA
- Full Text:
- Description: Satisfying customers is fundamental to the marketing concept and has long been recognised as important, firstly in the economic discipline and subsequently in marketing and in business generally. In a competitive marketplace customer satisfaction is closely linked to the ability of the organisation to deliver quality. Therefore, organisations rely on the feedback received from customers about how satisfied or dissatisfied they are with product and service provision and their perceptions of the value received. The study examines the various product and service attributes that contribute to visitor satisfaction and experience, and evaluates the role of price-value perceptions and behavioural intentions. This examination was undertaken by the study of three tourism enterprises operating in the heritage tourism area. These included Sovereign Hill, which is an historic goldfields township; Brambuk, which is an indigenous cultural centre located in the Grampians in Western Victoria; and Werribee Mansion, which depicts the life of a wealthy farming family in the early periods in Victoria. This study has provided insight into the understanding of visitor satisfaction in tourism enterprises by evaluating the relationship between overall satisfaction and dissatisfaction and how these influence revisit and recommending behaviour, as well as the influence of price-value perceptions on satisfaction, experience and enjoyment. The study shows that price-value dissatisfaction impacts negatively on the willingness of visitors to recommend a tourism venue to others and that price dissatisfaction tends to impact negatively on satisfaction. The results provide some insight into what contributes to tourist satisfaction, enjoyment and experience. The findings are expected to assist strategic and operational managers in their quest for continued quality enhancement and the provision and renewal of tourism products and services. It is expected that the findings will provide some guidance to managers, tourism operators, marketers and researchers alike in developing well informed data and analyses that are the key to strategic and competitive advantage.
- Description: Doctor of Business Adminstration
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
Susceptibility of rehabilitated mine batter surface to mass movement
- Authors: Allen, Tristan
- Date: 2018
- Type: Text , Thesis , Masters
- Full Text:
- Description: The goal of the research is to quantify coal properties that may affect the processes and controls governing rehabilitated brown coal mine surface mass movements. The research investigates weathering of coal and assesses the difference in strength characteristics between fresh and weathered coal. In addition to quantifying the mechanical properties of coal surfaces in a rehabilitated slope, permeability changes due to weathering of coal are also investigated. Changes in coal strength influence sliding resistance. Changes in coal permeability impact pore pressures above the coal surface, which may also affect sliding resistance on the coal – cover interface. To assess these issues, direct and residual shear tests were used to investigate the changes in shear strength due to weathering at low normal stresses applicable to shallow cover materials. Testing was undertaken with abrasive surfaces to simulate sliding on the contact coal surface beneath cover materials assuming that the cover material is stronger than the coal. The roughness of the abrasive surface proved to be unimportant for large strain shear strength. The shear strength for coal with different weathering and normal effective stresses was examined. Coal cohesion was found to be low, but some rebinding of coal would occur with time. A coal residual friction angle of 39.1 and 37.0 degrees was found for the unsaturated and saturated tested coal respectively. Permeability tests using oxygenated water were undertaken to investigate changes to brown coal permeability as a result of weathering. Even with low levels of oxidation achievable with the permeability test apparatus, coal permeability dropped over time. While the magnitude of the reduction was not large for low oxidation magnitudes, the impact on permeability was demonstrated. A weathering index was developed as part of the study to provide a quantitative basis for assessing the weathered state of coal samples. The index employed changes to Fourier Transform Infrared Spectroscopy (FTIR) spectra to define the state of weathering. To assess the rate and magnitude of weathering of coal through oxidation an autoclave was used to artificially weather brown coal. Fourier Transform Infrared Spectroscopy and Gas Chromatography used to analyse the results. As for the permeability testing the autoclave experiments could not be run for sufficient time to progress to complete weathering by oxidation. Nevertheless the principles of the test and the equipment specifications were developed so that they could be used in future to complete the determination of weathering rates. The research has demonstrated the importance of understanding coal weathering at the upper boundary of a rehabilitated coal surface to the potential for cover mass movements due to sliding at the coal cover interface.
- Description: Masters by Research
- Authors: Allen, Tristan
- Date: 2018
- Type: Text , Thesis , Masters
- Full Text:
- Description: The goal of the research is to quantify coal properties that may affect the processes and controls governing rehabilitated brown coal mine surface mass movements. The research investigates weathering of coal and assesses the difference in strength characteristics between fresh and weathered coal. In addition to quantifying the mechanical properties of coal surfaces in a rehabilitated slope, permeability changes due to weathering of coal are also investigated. Changes in coal strength influence sliding resistance. Changes in coal permeability impact pore pressures above the coal surface, which may also affect sliding resistance on the coal – cover interface. To assess these issues, direct and residual shear tests were used to investigate the changes in shear strength due to weathering at low normal stresses applicable to shallow cover materials. Testing was undertaken with abrasive surfaces to simulate sliding on the contact coal surface beneath cover materials assuming that the cover material is stronger than the coal. The roughness of the abrasive surface proved to be unimportant for large strain shear strength. The shear strength for coal with different weathering and normal effective stresses was examined. Coal cohesion was found to be low, but some rebinding of coal would occur with time. A coal residual friction angle of 39.1 and 37.0 degrees was found for the unsaturated and saturated tested coal respectively. Permeability tests using oxygenated water were undertaken to investigate changes to brown coal permeability as a result of weathering. Even with low levels of oxidation achievable with the permeability test apparatus, coal permeability dropped over time. While the magnitude of the reduction was not large for low oxidation magnitudes, the impact on permeability was demonstrated. A weathering index was developed as part of the study to provide a quantitative basis for assessing the weathered state of coal samples. The index employed changes to Fourier Transform Infrared Spectroscopy (FTIR) spectra to define the state of weathering. To assess the rate and magnitude of weathering of coal through oxidation an autoclave was used to artificially weather brown coal. Fourier Transform Infrared Spectroscopy and Gas Chromatography used to analyse the results. As for the permeability testing the autoclave experiments could not be run for sufficient time to progress to complete weathering by oxidation. Nevertheless the principles of the test and the equipment specifications were developed so that they could be used in future to complete the determination of weathering rates. The research has demonstrated the importance of understanding coal weathering at the upper boundary of a rehabilitated coal surface to the potential for cover mass movements due to sliding at the coal cover interface.
- Description: Masters by Research
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
Decision making processes within educated intercultural marriages in Australia
- Authors: Alnaimi, Suleiman
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: In recent years, the world–wide phenomena of globalization and increasingly flexible social norms have contributed to an increase in intercultural relationships, particularly in multicultural societies. Intercultural relationships have a higher risk of failure and lower marital satisfaction than same-culture marriages. The negotiation of important family decisions are known to lead to marital conflict, however few studies have examined how successful, intercultural couples make important decisions and maintain marital satisfaction. Six intercultural couples who met the criteria were recruited and interviewed (ie.12 individuals).Couples were interviewed longitudinally on how they make important family decisions. The educational levels of participants ranged from college degree to PhD degree. The participants represented diverse cultural backgrounds. The various racial and/or ethnic identifications of the intercultural married couples in this study represented the diversity of the racial and/or ethnic mixes in intercultural marriages within the general population. Prior to completing the conjoint, face to face interviews, each couple completed the Schwartz Value Survey to elicit their individual values. Values are known to motivate and underpin decisions and vary from culture to culture. Interviews revealed that, although cultural differences were clearly evident, these differences did not prevent effective decision making amongst intercultural couples. Instead, couples were successfully turning cultural differences into minor issues or even opportunities. Couples often managed three cultures within the nuclear family as all couples had children being raised in Australia. Couples reported that keys to marital success included developing common values, working towards agreed goals and awareness of their spouse’s culture, support and open communication. Intercultural couples interviewed displayed positive attitudes of commitment to their marriage, each other and family. Couples focused on what was best for the family when making decisions. They held firm beliefs that they were not that different from their partner, despite cultural differences. Themes to emerge from qualitative analysis of the interviews as factors underpinning successful inter-cultural marriages across the participants include shared faith, similar values and the creation of a third culture within an emerging global culture. Cultural differences were not found to be a significant factor when major family decisions were made. This thesis is the first to examine decision making among successful intercultural couples. Qualitative study has investigated couple decision-making from the same cultural background. This current study generates new insights on intercultural couple’s decision making processes, and provides unique perspectives on how successful, well-adjusted and highly educated intercultural couples negotiate important family decisions. The findings of this study have the potential to add to the limited knowledge available on intercultural marriage and cross-cultural adjustment and has implications for counsellors and marriage / family therapists working with cross-cultural couples.
- Description: Doctor of Philosophy
- Authors: Alnaimi, Suleiman
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: In recent years, the world–wide phenomena of globalization and increasingly flexible social norms have contributed to an increase in intercultural relationships, particularly in multicultural societies. Intercultural relationships have a higher risk of failure and lower marital satisfaction than same-culture marriages. The negotiation of important family decisions are known to lead to marital conflict, however few studies have examined how successful, intercultural couples make important decisions and maintain marital satisfaction. Six intercultural couples who met the criteria were recruited and interviewed (ie.12 individuals).Couples were interviewed longitudinally on how they make important family decisions. The educational levels of participants ranged from college degree to PhD degree. The participants represented diverse cultural backgrounds. The various racial and/or ethnic identifications of the intercultural married couples in this study represented the diversity of the racial and/or ethnic mixes in intercultural marriages within the general population. Prior to completing the conjoint, face to face interviews, each couple completed the Schwartz Value Survey to elicit their individual values. Values are known to motivate and underpin decisions and vary from culture to culture. Interviews revealed that, although cultural differences were clearly evident, these differences did not prevent effective decision making amongst intercultural couples. Instead, couples were successfully turning cultural differences into minor issues or even opportunities. Couples often managed three cultures within the nuclear family as all couples had children being raised in Australia. Couples reported that keys to marital success included developing common values, working towards agreed goals and awareness of their spouse’s culture, support and open communication. Intercultural couples interviewed displayed positive attitudes of commitment to their marriage, each other and family. Couples focused on what was best for the family when making decisions. They held firm beliefs that they were not that different from their partner, despite cultural differences. Themes to emerge from qualitative analysis of the interviews as factors underpinning successful inter-cultural marriages across the participants include shared faith, similar values and the creation of a third culture within an emerging global culture. Cultural differences were not found to be a significant factor when major family decisions were made. This thesis is the first to examine decision making among successful intercultural couples. Qualitative study has investigated couple decision-making from the same cultural background. This current study generates new insights on intercultural couple’s decision making processes, and provides unique perspectives on how successful, well-adjusted and highly educated intercultural couples negotiate important family decisions. The findings of this study have the potential to add to the limited knowledge available on intercultural marriage and cross-cultural adjustment and has implications for counsellors and marriage / family therapists working with cross-cultural couples.
- 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
The effects of norepinephrine on the proliferation, lipid-uptake and mRNA expression of inflammatory markers in vascular smooth muscle cells
- Authors: Anesi, Jack
- Date: 2020
- Type: Text , Thesis , Master of Applied Science
- Full Text:
- Description: Background: Cardiovascular disease (CVD) is the leading, global cause of death. Elevated levels of norepinephrine (NE) are associated with CVDs such as coronary heart disease with atherosclerosis as the underlying mechanism. Oxidised low-density lipoprotein (OxLDL) has been shown to play an integral role in the formation of atherosclerosis within the vasculature. Previous studies suggest a decrease in NE by renal denervation is associated with enhanced atherosclerosis in mice and NE has anti-inflammatory effects. Therefore, we hypothesised that NE may protect against atherosclerosis. This study aimed to investigate the effects of NE on cellular proliferation, OxLDL uptake and mRNA expression of inflammatory markers in mouse aortic vascular smooth muscle cells (VSMCs), a key cell type involved in atherosclerosis. Methods: Mouse aortic VSMCs were cultured and treated with NE for three consecutive days. Cell proliferation was measured using the trypan blue exclusion and MTS proliferation assays. VSMCs were exposed to fluorescence-labelled OxLDL in the presence or absence of NE for 24 hours. Cellular uptake of fluorescence-labelled OxLDL was visualised by confocal microscopy and analysed for mean fluorescence intensity using ImageJ. To investigate the involvement of NE receptors, the
- Description: Masters
- Authors: Anesi, Jack
- Date: 2020
- Type: Text , Thesis , Master of Applied Science
- Full Text:
- Description: Background: Cardiovascular disease (CVD) is the leading, global cause of death. Elevated levels of norepinephrine (NE) are associated with CVDs such as coronary heart disease with atherosclerosis as the underlying mechanism. Oxidised low-density lipoprotein (OxLDL) has been shown to play an integral role in the formation of atherosclerosis within the vasculature. Previous studies suggest a decrease in NE by renal denervation is associated with enhanced atherosclerosis in mice and NE has anti-inflammatory effects. Therefore, we hypothesised that NE may protect against atherosclerosis. This study aimed to investigate the effects of NE on cellular proliferation, OxLDL uptake and mRNA expression of inflammatory markers in mouse aortic vascular smooth muscle cells (VSMCs), a key cell type involved in atherosclerosis. Methods: Mouse aortic VSMCs were cultured and treated with NE for three consecutive days. Cell proliferation was measured using the trypan blue exclusion and MTS proliferation assays. VSMCs were exposed to fluorescence-labelled OxLDL in the presence or absence of NE for 24 hours. Cellular uptake of fluorescence-labelled OxLDL was visualised by confocal microscopy and analysed for mean fluorescence intensity using ImageJ. To investigate the involvement of NE receptors, the
- Description: Masters
Using digital image analysis for assessing the quality of wheat and barley
- Authors: Armstrong, Bruce
- Date: 2004
- Type: Text , Thesis , Masters
- Full Text:
- Description: This thesis explores the issues involved in developing a relatively low-cost digital imaging analysis (DIA) system fot the quality assessment of wheat and barley using commonly available equipment. It also explores the capability of such a system to provide rapid and accurate assessments.
- Description: Master of Applied Science by research
- Authors: Armstrong, Bruce
- Date: 2004
- Type: Text , Thesis , Masters
- Full Text:
- Description: This thesis explores the issues involved in developing a relatively low-cost digital imaging analysis (DIA) system fot the quality assessment of wheat and barley using commonly available equipment. It also explores the capability of such a system to provide rapid and accurate assessments.
- Description: Master of Applied Science by research
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)