A new perceptual dissimilarity measure for image retrieval and clustering
- Authors: Shojanazeri, Hamid
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Image retrieval and clustering are two important tools for analysing and organising images. Dissimilarity measure is central to both image retrieval and clustering. The performance of image retrieval and clustering algorithms depends on the effectiveness of the dissimilarity measure. ‘Minkowski’ distance, or more specifically, ‘Euclidean’ distance, is the most widely used dissimilarity measure in image retrieval and clustering. Euclidean distance depends only on the geometric position of two data instances in the feature space and completely ignores the data distribution. However, data distribution has an effect on human perception. The argument that two data instances in a dense area are more perceptually dissimilar than the same two instances in a sparser area, is proposed by psychologists. Based on this idea, a dissimilarity measure called, ‘mp’, has been proposed to address Euclidean distance’s limitation of ignoring the data distribution. Here, mp relies on data distribution to calculate the dissimilarity between two instances. As prescribed in mp, higher data mass between two data instances implies higher dissimilarity, and vice versa. mp relies only on data distribution and completely ignores the geometric distance in its calculations. In the aggregation of dissimilarities between two instances over all the dimensions in feature space, both Euclidean distance and mp give same priority to all the dimensions. This may result in a situation that the final dissimilarity between two data instances is determined by a few dimensions of feature vectors with relatively much higher values. As a result, the dissimilarity derived may not align well with human perception. The need to address the limitations of Minkowski distance measures, along with the importance of a dissimilarity measure that considers both geometric distance and the perceptual effect of data distribution in measuring dissimilarity between images motivated this thesis. It studies the performance of mp for image retrieval. It investigates a new dissimilarity measure that combines both Euclidean distance and data distribution. In addition to these, it studies the performance of such a dissimilarity measure for image retrieval and clustering. Our performance study of mp for image retrieval shows that relying only on data distribution to measure the dissimilarity results in some situations, where the mp’s measurement is contrary to human perception. This thesis introduces a new dissimilarity measure called, perceptual dissimilarity measure (PDM). PDM considers the perceptual effect of data distribution in combination with Euclidean distance. PDM has two variants, PDM1 and PDM2. PDM1 focuses on improving mp by weighting it using Euclidean distance in situations where mp may not retrieve accurate results. PDM2 considers the effect of data distribution on the perceived dissimilarity measured by Euclidean distance. PDM2 proposes a weighting system for Euclidean distance using a logarithmic transform of data mass. The proposed PDM variants have been used as alternatives to Euclidean distance and mp to improve the accuracy in image retrieval. Our results show that PDM2 has consistently performed the best, compared to Euclidean distance, mp and PDM1. PDM1’s performance was not consistent, although it has performed better than mp in all the experiments, but it could not outperform Euclidean distance in some cases. Following the promising results of PDM2 in image retrieval, we have studied its performance for image clustering. k-means is the most widely used clustering algorithm in scientific and industrial applications. k-medoids is the closest clustering algorithm to k-means. Unlike k-means which works only with Euclidean distance, k-medoids gives the option to choose the arbitrary dissimilarity measure. We have used Euclidean distance, mp and PDM2 as the dissimilarity measure in k-medoids and compared the results with k-means. Our clustering results show that PDM2 has perfromed overally the best. This confirms our retrieval results and identifies PDM2 as a suitable dissimilarity measure for image retrieval and clustering.
- Description: Doctor of Philosophy
- Authors: Shojanazeri, Hamid
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Image retrieval and clustering are two important tools for analysing and organising images. Dissimilarity measure is central to both image retrieval and clustering. The performance of image retrieval and clustering algorithms depends on the effectiveness of the dissimilarity measure. ‘Minkowski’ distance, or more specifically, ‘Euclidean’ distance, is the most widely used dissimilarity measure in image retrieval and clustering. Euclidean distance depends only on the geometric position of two data instances in the feature space and completely ignores the data distribution. However, data distribution has an effect on human perception. The argument that two data instances in a dense area are more perceptually dissimilar than the same two instances in a sparser area, is proposed by psychologists. Based on this idea, a dissimilarity measure called, ‘mp’, has been proposed to address Euclidean distance’s limitation of ignoring the data distribution. Here, mp relies on data distribution to calculate the dissimilarity between two instances. As prescribed in mp, higher data mass between two data instances implies higher dissimilarity, and vice versa. mp relies only on data distribution and completely ignores the geometric distance in its calculations. In the aggregation of dissimilarities between two instances over all the dimensions in feature space, both Euclidean distance and mp give same priority to all the dimensions. This may result in a situation that the final dissimilarity between two data instances is determined by a few dimensions of feature vectors with relatively much higher values. As a result, the dissimilarity derived may not align well with human perception. The need to address the limitations of Minkowski distance measures, along with the importance of a dissimilarity measure that considers both geometric distance and the perceptual effect of data distribution in measuring dissimilarity between images motivated this thesis. It studies the performance of mp for image retrieval. It investigates a new dissimilarity measure that combines both Euclidean distance and data distribution. In addition to these, it studies the performance of such a dissimilarity measure for image retrieval and clustering. Our performance study of mp for image retrieval shows that relying only on data distribution to measure the dissimilarity results in some situations, where the mp’s measurement is contrary to human perception. This thesis introduces a new dissimilarity measure called, perceptual dissimilarity measure (PDM). PDM considers the perceptual effect of data distribution in combination with Euclidean distance. PDM has two variants, PDM1 and PDM2. PDM1 focuses on improving mp by weighting it using Euclidean distance in situations where mp may not retrieve accurate results. PDM2 considers the effect of data distribution on the perceived dissimilarity measured by Euclidean distance. PDM2 proposes a weighting system for Euclidean distance using a logarithmic transform of data mass. The proposed PDM variants have been used as alternatives to Euclidean distance and mp to improve the accuracy in image retrieval. Our results show that PDM2 has consistently performed the best, compared to Euclidean distance, mp and PDM1. PDM1’s performance was not consistent, although it has performed better than mp in all the experiments, but it could not outperform Euclidean distance in some cases. Following the promising results of PDM2 in image retrieval, we have studied its performance for image clustering. k-means is the most widely used clustering algorithm in scientific and industrial applications. k-medoids is the closest clustering algorithm to k-means. Unlike k-means which works only with Euclidean distance, k-medoids gives the option to choose the arbitrary dissimilarity measure. We have used Euclidean distance, mp and PDM2 as the dissimilarity measure in k-medoids and compared the results with k-means. Our clustering results show that PDM2 has perfromed overally the best. This confirms our retrieval results and identifies PDM2 as a suitable dissimilarity measure for image retrieval and clustering.
- Description: Doctor of Philosophy
Abnormalities in T cell lineages from patients with Langerhans cell histiocytosis
- Authors: Mitchell, Jenée
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Langerhans cell histiocytosis (LCH) is a rare inflammatory disease characterised by lesions containing CD1a+ myeloid lineage ‘LCH’ cells. Other immune cells such as T cells are also present within LCH lesions and the cytokine milieu suggests T cell activation. T cells have an established role in regulating cellular immunity and there is already evidence that multiple T cell lineages are enriched in LCH lesions, implying that they may have a role in LCH pathogenesis. Foxp3+ regulatory T cells (Tregs) and the immune suppressive cytokine, transforming growth factor beta (TGF-
- Description: Doctor of Philosophy
- Authors: Mitchell, Jenée
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Langerhans cell histiocytosis (LCH) is a rare inflammatory disease characterised by lesions containing CD1a+ myeloid lineage ‘LCH’ cells. Other immune cells such as T cells are also present within LCH lesions and the cytokine milieu suggests T cell activation. T cells have an established role in regulating cellular immunity and there is already evidence that multiple T cell lineages are enriched in LCH lesions, implying that they may have a role in LCH pathogenesis. Foxp3+ regulatory T cells (Tregs) and the immune suppressive cytokine, transforming growth factor beta (TGF-
- Description: Doctor of Philosophy
Anti-war, radical youth revolt, Victoria, 1965-1975
- Authors: Butler, Nicholas
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis is a political history of the emergence and evolution of selected radical, left, student and workers movements in Victoria between 1965 and 1975. It examines the development of radical alliances, demonstrations and public actions using documentary materials and oral accounts provided during interviews. It argues that the radical left movement in Victoria began within the Monash University Labor Club, which subsequently generated radical groups outside the university. During this timeframe, both military conscription for the Vietnam War and the war itself became focal points for oppositional political mobilisation in Victoria. In 1967, the Monash Labor Club’s disruptive campaign against university authority was sufficiently popular for the club to turn its attention to disrupting the war effort. Soon, its locus of operations shifted into the general anti-war movement and the Labor Club established new, non-student, and avowedly communist and revolutionary organisations. Roughly termed the “Maoists,” by 1970 these organisations coalesced into the Worker Student Alliance (WSA), which grew rapidly to become a “left-wing” body that challenged the leadership of the established “left” organisations. The cessation of Australia’s involvement in the Vietnam War removed a major cause for radical action and, despite the generation of some important campaigns to replace it, the WSA dissolved itself in 1974.
- Description: Doctor of Philosophy
- Authors: Butler, Nicholas
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis is a political history of the emergence and evolution of selected radical, left, student and workers movements in Victoria between 1965 and 1975. It examines the development of radical alliances, demonstrations and public actions using documentary materials and oral accounts provided during interviews. It argues that the radical left movement in Victoria began within the Monash University Labor Club, which subsequently generated radical groups outside the university. During this timeframe, both military conscription for the Vietnam War and the war itself became focal points for oppositional political mobilisation in Victoria. In 1967, the Monash Labor Club’s disruptive campaign against university authority was sufficiently popular for the club to turn its attention to disrupting the war effort. Soon, its locus of operations shifted into the general anti-war movement and the Labor Club established new, non-student, and avowedly communist and revolutionary organisations. Roughly termed the “Maoists,” by 1970 these organisations coalesced into the Worker Student Alliance (WSA), which grew rapidly to become a “left-wing” body that challenged the leadership of the established “left” organisations. The cessation of Australia’s involvement in the Vietnam War removed a major cause for radical action and, despite the generation of some important campaigns to replace it, the WSA dissolved itself in 1974.
- Description: Doctor of Philosophy
Assessing healthcare providers' performance with and without risk adjustment
- Authors: Morales-Silva, Daniel
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: This study focuses on how healthcare data can be used to draw comparisons between healthcare providers (surgeons or hospitals). Depending on the type of access to datasets, these comparisons can be done with or without risk adjustment. For us, risk adjustment refers to the use of patient-level information to explain variation in healthcare spending, resource utilisation and health outcomes. For unadjusted comparisons, we highlight the diagnostic potential that radar plots offer for reporting on outcome indicators. These outcome indicators were obtained from hospital admissions of patients undergoing certain surgical procedures. We address two drawbacks of radar plots: presence of missing information and order of indicators. By introducing a consolidated view at provider level, we define an uncomplicated ranking of providers which can be used to identify potential low and high performers. For risk adjusted comparisons, we introduce a novel and robust methodology that enables comparisons of healthcare providers across multiple hierarchies, namely, surgeons, teams, departments and hospitals, using a consistent approach. Our methodology puts the patient at the centre of the analysis, and thus, can be used for personalised predictions (e.g. expected length of stay, costs and probability of being transferred to intensive care unit). Our findings suggest that the observed variation in selected outcome indicators, such as length of stay and charges of healthcare providers, cannot be explained by patient characteristics alone. Importantly, we have also observed that the perceived performance, on selected outcome indicators, of providers can change substantially following risk adjustment. Healthcare is unique in that clinical expertise is essential in guiding decision making and in informing all statistical models that seek to describe patient outcomes. For future iterations of our models, we will seek greater clinical input.
- Description: Doctor of Philosophy
- Authors: Morales-Silva, Daniel
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: This study focuses on how healthcare data can be used to draw comparisons between healthcare providers (surgeons or hospitals). Depending on the type of access to datasets, these comparisons can be done with or without risk adjustment. For us, risk adjustment refers to the use of patient-level information to explain variation in healthcare spending, resource utilisation and health outcomes. For unadjusted comparisons, we highlight the diagnostic potential that radar plots offer for reporting on outcome indicators. These outcome indicators were obtained from hospital admissions of patients undergoing certain surgical procedures. We address two drawbacks of radar plots: presence of missing information and order of indicators. By introducing a consolidated view at provider level, we define an uncomplicated ranking of providers which can be used to identify potential low and high performers. For risk adjusted comparisons, we introduce a novel and robust methodology that enables comparisons of healthcare providers across multiple hierarchies, namely, surgeons, teams, departments and hospitals, using a consistent approach. Our methodology puts the patient at the centre of the analysis, and thus, can be used for personalised predictions (e.g. expected length of stay, costs and probability of being transferred to intensive care unit). Our findings suggest that the observed variation in selected outcome indicators, such as length of stay and charges of healthcare providers, cannot be explained by patient characteristics alone. Importantly, we have also observed that the perceived performance, on selected outcome indicators, of providers can change substantially following risk adjustment. Healthcare is unique in that clinical expertise is essential in guiding decision making and in informing all statistical models that seek to describe patient outcomes. For future iterations of our models, we will seek greater clinical input.
- Description: Doctor of Philosophy
Avenue and Arch : Ballarat's commemoration. How are community attitudes to war and peace reflected in the civic management of the Avenue of Honour and the Arch of Victory?
- Authors: Roberts, Philip
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis examines the importance of memory, commemoration, heritage and militarism in relation to Ballarat’s Avenue of Honour and Arch of Victory. Inspired by Ken Inglis and other historians who have analysed war commemoration, the thesis argues that, led by the Lucas clothing company, Ballarat civic leaders and community members commemorated the war service and sacrifice of local soldiers, airmen, sailors and nurses by planting the 22-kilometre Avenue during 1917–19 and by constructing the prominent Arch in 1920. Although Ballarat voted against conscription in 1916 and 1917 and was a ‘divided’ society, the Avenue and Arch were able to unite members of the local community. From the 1920s, through memory and mythology during the civic maintenance of the Avenue and Arch, Australian community attitudes to war and peace were reflected, and a determined effort was made to remember the service and sacrifice of military personnel for all Australian wars. Discussion of the need for peace remained in the background until recent years. Important influences on the civic management were the collective memory of the so-called Lucas Girls, a group of former female employees of the Lucas clothing company, and of the members of the Arch of Victory/Avenue of Honour Committee. Increasingly, the embracing of the Anzac legend and an emphasis on loss and grief was reflected in the civic management. By 2017 the Avenue and Arch were in pristine condition and, through the Garden of the Grieving Mother, had transformed to symbolise the importance of remembering the sacrifices and grief of war and the need for peace. The project was based on documentary research and oral history, using an examination of newspaper and other documentary accounts from 1917–2017, a study of Arch of Victory/Avenue of Honour Committee papers and conservation management plans, research of relevant books and articles, landscape fieldwork and interviews with 26 people.
- Description: Doctor of Philosophy
- Authors: Roberts, Philip
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis examines the importance of memory, commemoration, heritage and militarism in relation to Ballarat’s Avenue of Honour and Arch of Victory. Inspired by Ken Inglis and other historians who have analysed war commemoration, the thesis argues that, led by the Lucas clothing company, Ballarat civic leaders and community members commemorated the war service and sacrifice of local soldiers, airmen, sailors and nurses by planting the 22-kilometre Avenue during 1917–19 and by constructing the prominent Arch in 1920. Although Ballarat voted against conscription in 1916 and 1917 and was a ‘divided’ society, the Avenue and Arch were able to unite members of the local community. From the 1920s, through memory and mythology during the civic maintenance of the Avenue and Arch, Australian community attitudes to war and peace were reflected, and a determined effort was made to remember the service and sacrifice of military personnel for all Australian wars. Discussion of the need for peace remained in the background until recent years. Important influences on the civic management were the collective memory of the so-called Lucas Girls, a group of former female employees of the Lucas clothing company, and of the members of the Arch of Victory/Avenue of Honour Committee. Increasingly, the embracing of the Anzac legend and an emphasis on loss and grief was reflected in the civic management. By 2017 the Avenue and Arch were in pristine condition and, through the Garden of the Grieving Mother, had transformed to symbolise the importance of remembering the sacrifices and grief of war and the need for peace. The project was based on documentary research and oral history, using an examination of newspaper and other documentary accounts from 1917–2017, a study of Arch of Victory/Avenue of Honour Committee papers and conservation management plans, research of relevant books and articles, landscape fieldwork and interviews with 26 people.
- Description: Doctor of Philosophy
Beyond the natural : perceptions of spirituality and spiritual nurturing in volunteer pastoral care workers in christian ministry : implications for training
- Job, Kay
- Authors: Job, Kay
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Practical and evidence-based research is scarce regarding the perceptions of spirituality and spiritual nurturing of volunteer pastoral care workers. This study set out to explore perceptions of spirituality and spiritual nurturing of volunteer pastoral care workers in a Christian ministry. The aim was to identify what influence their spirituality had on ministry, whether there were links between spiritual experiences, spiritual nurturing and spiritual growth and to develop relevant recommendations to improve training and praxis within the field of pastoral care, an area of increasing interest and demand within the Christian tradition. Thirty participants from an interdenominational volunteer ministry in the Christian tradition, Victorious Ministry Through Christ (VMTC), were interviewed and data were analysed using principles of Grounded Theory to inform subjective spiritual experiences and discover themes regarding spiritual awareness, sensitivity, and effective practice. There were strong indications that a totally dependent, reciprocal relationship exists between spirituality and the ability to minister, suggesting a negation of ability could occur by an absence, unawareness of, or disengagement from the existence of a spiritual dimension. The extent to which an individual was able to effectively and sensitively offer pastoral care was dependent on the degree to which properties of Substantive Spirituality were appropriated, demonstrated through strands of spiritual Sensibility, capacity for Reciprocity, and response to Modification, which combined to form Integrative Spiritual Function (ISF). ISF supported mature functioning of the individual personally, was pre-eminent to formation and effective ministry, and integrative for the whole person. ISF also informed the development of SIFTable; an example of an appraisal tool for use in pastoral care contexts to gauge competency. Recommendations regarding thoughtful and appropriate training of volunteer pastoral care personnel may assist in the formative process associated with ministry to ensure a holistic response to pastoral needs of the volunteer, and the recipient of ministry.
- Description: Doctor of Philosophy
- Authors: Job, Kay
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Practical and evidence-based research is scarce regarding the perceptions of spirituality and spiritual nurturing of volunteer pastoral care workers. This study set out to explore perceptions of spirituality and spiritual nurturing of volunteer pastoral care workers in a Christian ministry. The aim was to identify what influence their spirituality had on ministry, whether there were links between spiritual experiences, spiritual nurturing and spiritual growth and to develop relevant recommendations to improve training and praxis within the field of pastoral care, an area of increasing interest and demand within the Christian tradition. Thirty participants from an interdenominational volunteer ministry in the Christian tradition, Victorious Ministry Through Christ (VMTC), were interviewed and data were analysed using principles of Grounded Theory to inform subjective spiritual experiences and discover themes regarding spiritual awareness, sensitivity, and effective practice. There were strong indications that a totally dependent, reciprocal relationship exists between spirituality and the ability to minister, suggesting a negation of ability could occur by an absence, unawareness of, or disengagement from the existence of a spiritual dimension. The extent to which an individual was able to effectively and sensitively offer pastoral care was dependent on the degree to which properties of Substantive Spirituality were appropriated, demonstrated through strands of spiritual Sensibility, capacity for Reciprocity, and response to Modification, which combined to form Integrative Spiritual Function (ISF). ISF supported mature functioning of the individual personally, was pre-eminent to formation and effective ministry, and integrative for the whole person. ISF also informed the development of SIFTable; an example of an appraisal tool for use in pastoral care contexts to gauge competency. Recommendations regarding thoughtful and appropriate training of volunteer pastoral care personnel may assist in the formative process associated with ministry to ensure a holistic response to pastoral needs of the volunteer, and the recipient of ministry.
- Description: Doctor of Philosophy
Beyond the princess, the priestess and the galactic kitchen sink: Reformulation of feminine roles in certain work of Lois McMaster Bujold
- Authors: Herington, Caitlin
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: In this thesis I examine the Science Fiction and Fantasy works of Lois McMaster Bujold in the Vorkosigan Series and Chalion Series, in particular the way she reformulates women’s roles and identities in society through the characters presented in these novels. I use the term Speculative Fiction as an umbrella term that encompasses both Science Fiction and Fantasy as modes of speculation, in that they both rely on extrapolation and estrangement as narrative features. My main proposition is that Bujold is an important transitional figure in speculative fiction between second and third wave feminist thinking. Although her work mimics some distinctive features of speculative fiction that utilise patriarchal structures and traditional gender norms, it is not limited by them. As a result, Bujold conveys a more complex and insightful understanding of gender. The research method of this thesis is the close reading of a range of sample texts from Bujold’s Vorkosigan Series and Chalion Series which feature female protagonists. I seek to explore the discussion of gender relations and reformulation that occurs within them in the context of both speculative and feminist criticism. Bujold’s exploration of the identities and social roles of women in these fictional worlds is complex and challenging, using a range of approaches from simple reversal, to hybridity of gender, to more complex partial positions. This thesis argues that she takes an implicitly feminist approach, focussing on female experiences and examining the modes of social control and exercise of power within patriarchal social structures as they impact on women. Science Fiction and Fantasy often seem to reiterate traditional patriarchal hierarchies. Validating gender norms that conform to social expectations rather than challenging them. Bujold is presented in this thesis as utilising established norms and tropes such that her texts are easily identified as examples of Science Fiction and Fantasy, but in other ways her reformulations present radical challenges to cultural expectations of gender. This thesis reveals that social critique and reformulation of gender roles is possible and powerful in both Science Fiction and Fantasy by examining the work of a significant author whose work has lacked critical attention until recently. Although numerous studies have examined the way gender has been treated in Science Fiction and Fantasy, the unique contribution of this thesis is to examine an author previously under-studied and to consider the patterns of these reformulations as expressed in Bujold’s works.
- Description: Doctor of Philosophy
- Authors: Herington, Caitlin
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: In this thesis I examine the Science Fiction and Fantasy works of Lois McMaster Bujold in the Vorkosigan Series and Chalion Series, in particular the way she reformulates women’s roles and identities in society through the characters presented in these novels. I use the term Speculative Fiction as an umbrella term that encompasses both Science Fiction and Fantasy as modes of speculation, in that they both rely on extrapolation and estrangement as narrative features. My main proposition is that Bujold is an important transitional figure in speculative fiction between second and third wave feminist thinking. Although her work mimics some distinctive features of speculative fiction that utilise patriarchal structures and traditional gender norms, it is not limited by them. As a result, Bujold conveys a more complex and insightful understanding of gender. The research method of this thesis is the close reading of a range of sample texts from Bujold’s Vorkosigan Series and Chalion Series which feature female protagonists. I seek to explore the discussion of gender relations and reformulation that occurs within them in the context of both speculative and feminist criticism. Bujold’s exploration of the identities and social roles of women in these fictional worlds is complex and challenging, using a range of approaches from simple reversal, to hybridity of gender, to more complex partial positions. This thesis argues that she takes an implicitly feminist approach, focussing on female experiences and examining the modes of social control and exercise of power within patriarchal social structures as they impact on women. Science Fiction and Fantasy often seem to reiterate traditional patriarchal hierarchies. Validating gender norms that conform to social expectations rather than challenging them. Bujold is presented in this thesis as utilising established norms and tropes such that her texts are easily identified as examples of Science Fiction and Fantasy, but in other ways her reformulations present radical challenges to cultural expectations of gender. This thesis reveals that social critique and reformulation of gender roles is possible and powerful in both Science Fiction and Fantasy by examining the work of a significant author whose work has lacked critical attention until recently. Although numerous studies have examined the way gender has been treated in Science Fiction and Fantasy, the unique contribution of this thesis is to examine an author previously under-studied and to consider the patterns of these reformulations as expressed in Bujold’s works.
- 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
Characterisation of the deformation behaviour of unbound granular materials using repeated load triaxial testing
- Authors: Zhalehjoo, Negin
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Unbound Granular Materials (UGMs) are used in the base/subbase layers of flexible pavements for the majority of roads around the world. The deterioration of pavements increases with the increase of traffic loadings. To ensure the long-term performance and serviceability of pavement structures through a realistic design, the precise evaluation and comprehensive characterisation of the resilient and permanent deformation behaviour of pavement materials are essential. The present PhD study aims to investigate the characterisation of the resilient and permanent deformation behaviour of four road base UGMs sourced from quarries in Victoria, Australia, using Repeated Load Triaxial (RLT) testing. The triaxial system used in this study is instrumented with four axial deformation measurement transducers to achieve highly precise measurements and to evaluate the effect of instrumentation on the resilient modulus of UGMs. The resilient Poisson’s ratio of the studied UGMs is also determined using a radial Hall-Effect transducer. Moreover, a series of permanent deformation tests is performed to precisely characterise the axial and radial permanent deformation behaviour of UGMs and investigate the factors that may significantly influence the accumulated axial and radial permanent deformations. Finally, three permanent deformation models incorporated with a time-hardening procedure are employed to predict the magnitude of permanent strain for multiple stress levels of the RLT test. The predictions using the employed models are then compared against the measured values to evaluate the suitability of the models and to identify the model that best predicts the strain accumulation behaviour of the tested UGMs. While this study focuses on the resilient and permanent deformation behaviour of four Victorian UGMs under repeated loading, the knowledge generated from this comprehensive investigation will contribute towards the global development of more reliable methods for evaluating the long-term performance of pavement structures and minimising road maintenance and repair costs.
- Description: Doctor of Philosophy
- Authors: Zhalehjoo, Negin
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Unbound Granular Materials (UGMs) are used in the base/subbase layers of flexible pavements for the majority of roads around the world. The deterioration of pavements increases with the increase of traffic loadings. To ensure the long-term performance and serviceability of pavement structures through a realistic design, the precise evaluation and comprehensive characterisation of the resilient and permanent deformation behaviour of pavement materials are essential. The present PhD study aims to investigate the characterisation of the resilient and permanent deformation behaviour of four road base UGMs sourced from quarries in Victoria, Australia, using Repeated Load Triaxial (RLT) testing. The triaxial system used in this study is instrumented with four axial deformation measurement transducers to achieve highly precise measurements and to evaluate the effect of instrumentation on the resilient modulus of UGMs. The resilient Poisson’s ratio of the studied UGMs is also determined using a radial Hall-Effect transducer. Moreover, a series of permanent deformation tests is performed to precisely characterise the axial and radial permanent deformation behaviour of UGMs and investigate the factors that may significantly influence the accumulated axial and radial permanent deformations. Finally, three permanent deformation models incorporated with a time-hardening procedure are employed to predict the magnitude of permanent strain for multiple stress levels of the RLT test. The predictions using the employed models are then compared against the measured values to evaluate the suitability of the models and to identify the model that best predicts the strain accumulation behaviour of the tested UGMs. While this study focuses on the resilient and permanent deformation behaviour of four Victorian UGMs under repeated loading, the knowledge generated from this comprehensive investigation will contribute towards the global development of more reliable methods for evaluating the long-term performance of pavement structures and minimising road maintenance and repair costs.
- Description: Doctor of Philosophy
Cognitive behaviour therapy for insomnia and depression among older adults : A mixed methods randomised controlled clinical trial
- Authors: Sadler, Paul
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Background A strong relationship exists between insomnia and depression, particularly among older adults (aged 65 years and older). Recently experts in the field of behavioural sleep medicine established cognitive behaviour therapy (CBT) was an effective treatment for comorbid insomnia, however, it was unknown whether cognitive behaviour therapy for insomnia (CBT-I) benefitted older adults with co-occurring depression (literature review published in Cognitive Behaviour Therapy). A mixed-methods randomised controlled clinical trial (RCT) was warranted within a community mental health setting to investigate the efficacy of CBT-I for older adults with comorbid insomnia and depression. Furthermore, no study had tested whether an advanced form of CBT-I that included additional positive mood-enhancing strategies produced better outcomes compared to a standard form of CBT-I that only targeted insomnia. It was anticipated that the results from such a trial could influence the evolution of treatment for older adults with these highly prevalent comorbid conditions. Methodology An RCT was conducted between 2014 and 2016 across Victoria, Australia, through Latrobe Regional Hospital‟s and Peninsula Health‟s Community Mental Health Services (protocol published in Trials). Seventy-two older adults with diagnosed comorbid insomnia and depression were randomly assigned to one of three group therapy conditions: cognitive behaviour therapy for insomnia (CBT-I, standard), cognitive behaviour therapy for insomnia plus positive mood strategies (CBT-I+, advanced), psychoeducation control group (PCG, control). The primary outcomes were insomnia severity (Insomnia Severity Index) and depression severity (Geriatric Depression Scale). Primary and secondary measures were collected at pre (week 0), post (week 8), and follow-up (week 20). Participants who completed the experiential conditions were invited to provide feedback in the form of semi- xvii structured focus groups following the final session of treatment. Thirty-one participants from six groups reflected on their experiences of participating in CBT-I and CBT-I+. Results Quantitative analyses demonstrated the experiential CBT conditions both generated significantly greater reductions in insomnia and depression severity compared to PCG from pre to post, which were maintained at follow-up. The standard and advanced conditions showed similar reductions on insomnia and depression severity at post and follow up. These results were also consistent for the secondary measures across conditions. Both active treatments demonstrated large effect sizes, high retention, and strong remission rates for older adults with insomnia and depression (published in journal SLEEP). A qualitative analysis was also conducted to explore the participants‟ experiences of treatment. Interview data from the reflective focus groups was transcribed into 424 sentences and 60 codes were extracted. Thirty-four initial themes emerged, which were finally transformed into 3 themes and 10 subthemes. The three themes were (1) positive experiences, (2) negative experiences, and (3) suggested modifications. The positive subthemes were (1a) therapists, (1b) togetherness, (1c) use of strategies reduced symptoms, and (1d) acceptance. The negative subthemes were (2a) persistent symptoms, (2b) program too condensed, and (2c) attendance obstacles. The suggested modifications were (3a) lengthen program, (3b) multi-dimensional learning, and (3c) multi-modal delivery options (manuscript under review in Aging and Mental Health). Conclusion This is the first RCT to demonstrate that specifically treating comorbid insomnia with CBT has an additional positive effect of improving depression for older adults with multiple comorbidities. Both CBT programs were effective at reducing insomnia and depression severity for older adults with comorbidity. Replication of this study is necessary with a larger sample size to conclusively establish whether the two interventions have different or equivalent effects. It was suggested mental health services that deliver treatment for comorbid insomnia with CBT may improve recovery outcomes for older adults with depression. Future CBT-I programs for older adults may be improved by increasing the length of therapy (e.g., 8 sessions to 12 sessions), adding multi-dimensional learning opportunities (e.g., visual/audio/mentorship), and offering various modes of treatment delivery (e.g., group, individual, internet, telephone).
- Description: Doctor of Philosophy
- Authors: Sadler, Paul
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Background A strong relationship exists between insomnia and depression, particularly among older adults (aged 65 years and older). Recently experts in the field of behavioural sleep medicine established cognitive behaviour therapy (CBT) was an effective treatment for comorbid insomnia, however, it was unknown whether cognitive behaviour therapy for insomnia (CBT-I) benefitted older adults with co-occurring depression (literature review published in Cognitive Behaviour Therapy). A mixed-methods randomised controlled clinical trial (RCT) was warranted within a community mental health setting to investigate the efficacy of CBT-I for older adults with comorbid insomnia and depression. Furthermore, no study had tested whether an advanced form of CBT-I that included additional positive mood-enhancing strategies produced better outcomes compared to a standard form of CBT-I that only targeted insomnia. It was anticipated that the results from such a trial could influence the evolution of treatment for older adults with these highly prevalent comorbid conditions. Methodology An RCT was conducted between 2014 and 2016 across Victoria, Australia, through Latrobe Regional Hospital‟s and Peninsula Health‟s Community Mental Health Services (protocol published in Trials). Seventy-two older adults with diagnosed comorbid insomnia and depression were randomly assigned to one of three group therapy conditions: cognitive behaviour therapy for insomnia (CBT-I, standard), cognitive behaviour therapy for insomnia plus positive mood strategies (CBT-I+, advanced), psychoeducation control group (PCG, control). The primary outcomes were insomnia severity (Insomnia Severity Index) and depression severity (Geriatric Depression Scale). Primary and secondary measures were collected at pre (week 0), post (week 8), and follow-up (week 20). Participants who completed the experiential conditions were invited to provide feedback in the form of semi- xvii structured focus groups following the final session of treatment. Thirty-one participants from six groups reflected on their experiences of participating in CBT-I and CBT-I+. Results Quantitative analyses demonstrated the experiential CBT conditions both generated significantly greater reductions in insomnia and depression severity compared to PCG from pre to post, which were maintained at follow-up. The standard and advanced conditions showed similar reductions on insomnia and depression severity at post and follow up. These results were also consistent for the secondary measures across conditions. Both active treatments demonstrated large effect sizes, high retention, and strong remission rates for older adults with insomnia and depression (published in journal SLEEP). A qualitative analysis was also conducted to explore the participants‟ experiences of treatment. Interview data from the reflective focus groups was transcribed into 424 sentences and 60 codes were extracted. Thirty-four initial themes emerged, which were finally transformed into 3 themes and 10 subthemes. The three themes were (1) positive experiences, (2) negative experiences, and (3) suggested modifications. The positive subthemes were (1a) therapists, (1b) togetherness, (1c) use of strategies reduced symptoms, and (1d) acceptance. The negative subthemes were (2a) persistent symptoms, (2b) program too condensed, and (2c) attendance obstacles. The suggested modifications were (3a) lengthen program, (3b) multi-dimensional learning, and (3c) multi-modal delivery options (manuscript under review in Aging and Mental Health). Conclusion This is the first RCT to demonstrate that specifically treating comorbid insomnia with CBT has an additional positive effect of improving depression for older adults with multiple comorbidities. Both CBT programs were effective at reducing insomnia and depression severity for older adults with comorbidity. Replication of this study is necessary with a larger sample size to conclusively establish whether the two interventions have different or equivalent effects. It was suggested mental health services that deliver treatment for comorbid insomnia with CBT may improve recovery outcomes for older adults with depression. Future CBT-I programs for older adults may be improved by increasing the length of therapy (e.g., 8 sessions to 12 sessions), adding multi-dimensional learning opportunities (e.g., visual/audio/mentorship), and offering various modes of treatment delivery (e.g., group, individual, internet, telephone).
- 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
Effective and efficient kernel-based image representations for classification and retrieval
- Authors: Karmakar, Priyabrata
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Image representation is a challenging task. In particular, in order to obtain better performances in different image processing applications such as video surveillance, autonomous driving, crime scene detection and automatic inspection, effective and efficient image representation is a fundamental need. The performance of these applications usually depends on how accurately images are classified into their corresponding groups or how precisely relevant images are retrieved from a database based on a query. Accuracy in image classification and precision in image retrieval depend on the effectiveness of image representation. Existing image representation methods have some limitations. For example, spatial pyramid matching, which is a popular method incorporating spatial information in image-level representation, has not been fully studied to date. In addition, the strengths of pyramid match kernel and spatial pyramid matching are not combined for better image matching. Kernel descriptors based on gradient, colour and shape overcome the limitations of histogram-based descriptors, but suffer from information loss, noise effects and high computational complexity. Furthermore, the combined performance of kernel descriptors has limitations related to computational complexity, higher dimensionality and lower effectiveness. Moreover, the potential of a global texture descriptor which is based on human visual perception has not been fully explored to date. Therefore, in this research project, kernel-based effective and efficient image representation methods are proposed to address the above limitations. An enhancement is made to spatial pyramid matching in terms of improved rotation invariance. This is done by investigating different partitioning schemes suitable to achieve rotation-invariant image representation and the proposal of a weight function for appropriate level contribution in image matching. In addition, the strengths of pyramid match kernel and spatial pyramid are combined to enhance matching accuracy between images. The existing kernel descriptors are modified and improved to achieve greater effectiveness, minimum noise effects, less dimensionality and lower computational complexity. A novel fusion approach is also proposed to combine the information related to all pixel attributes, before the descriptor extraction stage. Existing kernel descriptors are based only on gradient, colour and shape information. In this research project, a texture-based kernel descriptor is proposed by modifying an existing popular global texture descriptor. Finally, all the contributions are evaluated in an integrated system. The performances of the proposed methods are qualitatively and quantitatively evaluated on two to four different publicly available image databases. The experimental results show that the proposed methods are more effective and efficient in image representation than existing benchmark methods.
- Description: Doctor of Philosophy
- Authors: Karmakar, Priyabrata
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Image representation is a challenging task. In particular, in order to obtain better performances in different image processing applications such as video surveillance, autonomous driving, crime scene detection and automatic inspection, effective and efficient image representation is a fundamental need. The performance of these applications usually depends on how accurately images are classified into their corresponding groups or how precisely relevant images are retrieved from a database based on a query. Accuracy in image classification and precision in image retrieval depend on the effectiveness of image representation. Existing image representation methods have some limitations. For example, spatial pyramid matching, which is a popular method incorporating spatial information in image-level representation, has not been fully studied to date. In addition, the strengths of pyramid match kernel and spatial pyramid matching are not combined for better image matching. Kernel descriptors based on gradient, colour and shape overcome the limitations of histogram-based descriptors, but suffer from information loss, noise effects and high computational complexity. Furthermore, the combined performance of kernel descriptors has limitations related to computational complexity, higher dimensionality and lower effectiveness. Moreover, the potential of a global texture descriptor which is based on human visual perception has not been fully explored to date. Therefore, in this research project, kernel-based effective and efficient image representation methods are proposed to address the above limitations. An enhancement is made to spatial pyramid matching in terms of improved rotation invariance. This is done by investigating different partitioning schemes suitable to achieve rotation-invariant image representation and the proposal of a weight function for appropriate level contribution in image matching. In addition, the strengths of pyramid match kernel and spatial pyramid are combined to enhance matching accuracy between images. The existing kernel descriptors are modified and improved to achieve greater effectiveness, minimum noise effects, less dimensionality and lower computational complexity. A novel fusion approach is also proposed to combine the information related to all pixel attributes, before the descriptor extraction stage. Existing kernel descriptors are based only on gradient, colour and shape information. In this research project, a texture-based kernel descriptor is proposed by modifying an existing popular global texture descriptor. Finally, all the contributions are evaluated in an integrated system. The performances of the proposed methods are qualitatively and quantitatively evaluated on two to four different publicly available image databases. The experimental results show that the proposed methods are more effective and efficient in image representation than existing benchmark methods.
- Description: Doctor of Philosophy
Epidemiology, injury and illness prevention in Olympic combat sports
- Authors: Bromley, Sally
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Background: Olympic combat sports are commonly considered dangerous, however injury rates for these sports are not well understood. Isolated studies in combat sports have investigated injury, however these are mainly during competition, and therefore are unlikely to include significant or persistent injury which prevents athletes competing and participating in data collection. This thesis was undertaken as a series of linked studies, to provide further detail into the types, mechanisms and aetiology of injuries in combat sports. Methods: Study 1 was a systematic review that utilised the PRISMA guidelines to investigate the current evidence. Study 2 was a repeated measures study to examine the reliability of training load measures. Study 3 employed a longitudinal study design to assess the feasibility of injury, illness and training load monitoring. Finally, Study 4 was a cross-sectional cohort study that gathered perspectives of combat sport coaches and managers before and after an injury and illness prevention workshop. Results: Study 1 found one high-quality epidemiological study with low risk of bias in Judo. Variation in injury and illness definitions prevented cross-sport comparisons, however the injury incidence was comparable to other sports. In Study 2, rating of perceived exertion (RPE) was shown to have good stability across sessions (ICC=0.84), and no significant differences were found between coach (observed) and athlete (experienced) RPE (ordered logistic regression coefficient = 0.47 [1.51–0.57 95%CI]). Study 3 found that athlete engagement with the monitoring system was low, with only 13% of athletes entering data across a 12-week period. Irrespective of low engagement, 62 injuries and illnesses were recorded. In Study 4, combat sport coaches and managers were found to be generally well informed of the risk and seriousness of injury and illness, however, illness risk perceptions changed after the workshop (p=0.048). Discussion and Conclusion: Currently, cross-sport comparisons are not possible due to varying data methodology and study quality. Based upon the results presented in this thesis, RPE can be used as a tool to quantify training load in the sport of judo. Longitudinal surveillance of training load, injury and illness in combat sport is not currently feasible within the Australian system, due to low uptake and engagement. However, the collection of data on a large number of injuries and illnesses indicates that athletes are experiencing multiple, repeated health problems. Coaches and managers are well informed about injury and illness risk and seriousness, indicating that injury and illness prevention education alone may not translate to a decrease in injury and illness incidence in combat sport.
- Description: Doctor of Philosophy
- Authors: Bromley, Sally
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Background: Olympic combat sports are commonly considered dangerous, however injury rates for these sports are not well understood. Isolated studies in combat sports have investigated injury, however these are mainly during competition, and therefore are unlikely to include significant or persistent injury which prevents athletes competing and participating in data collection. This thesis was undertaken as a series of linked studies, to provide further detail into the types, mechanisms and aetiology of injuries in combat sports. Methods: Study 1 was a systematic review that utilised the PRISMA guidelines to investigate the current evidence. Study 2 was a repeated measures study to examine the reliability of training load measures. Study 3 employed a longitudinal study design to assess the feasibility of injury, illness and training load monitoring. Finally, Study 4 was a cross-sectional cohort study that gathered perspectives of combat sport coaches and managers before and after an injury and illness prevention workshop. Results: Study 1 found one high-quality epidemiological study with low risk of bias in Judo. Variation in injury and illness definitions prevented cross-sport comparisons, however the injury incidence was comparable to other sports. In Study 2, rating of perceived exertion (RPE) was shown to have good stability across sessions (ICC=0.84), and no significant differences were found between coach (observed) and athlete (experienced) RPE (ordered logistic regression coefficient = 0.47 [1.51–0.57 95%CI]). Study 3 found that athlete engagement with the monitoring system was low, with only 13% of athletes entering data across a 12-week period. Irrespective of low engagement, 62 injuries and illnesses were recorded. In Study 4, combat sport coaches and managers were found to be generally well informed of the risk and seriousness of injury and illness, however, illness risk perceptions changed after the workshop (p=0.048). Discussion and Conclusion: Currently, cross-sport comparisons are not possible due to varying data methodology and study quality. Based upon the results presented in this thesis, RPE can be used as a tool to quantify training load in the sport of judo. Longitudinal surveillance of training load, injury and illness in combat sport is not currently feasible within the Australian system, due to low uptake and engagement. However, the collection of data on a large number of injuries and illnesses indicates that athletes are experiencing multiple, repeated health problems. Coaches and managers are well informed about injury and illness risk and seriousness, indicating that injury and illness prevention education alone may not translate to a decrease in injury and illness incidence in combat sport.
- Description: Doctor of Philosophy
Epigenetic modifications in essential hypertension
- Authors: Wise, Ingrid
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Background: Hypertension (HTN) is a complex, multifactorial, quantitative trait under polygenic control that affects more than one billion people globally. Despite advances in our understanding of the pathophysiology of HTN and the implementation of more effective treatment and prevention strategies, HTN remains one of the world’s great public health problems. The accepted inference from genome-wide association studies (GWAS) is that the genetic code lays the foundation for transcriptomic changes and in turn physiological change. On the other side of the coin, environmental factors (smoking, diet, chemical exposure) can in turn affect DNA itself in genes relevant to blood pressure (BP). Variation in epigenetic forms of modification may thus explain additional phenotypic variation in BP and provide new clues to the physiological processes influencing its regulation. DNA methylation is one of these epigenetic mechanisms responsible for changes to gene expression, activated by interaction with environmental triggers. DNA methylation is a reversible epigenetic modifier of specific dinucleotide sites called CpGs, which consists of a transfer of a methyl group derived from S-adenosyl-L-methionine to position five of a cytosine ring, forming 5mC. Pathophysiologically, the kidney is known as the key organ of BP regulation and one of the most important contributors to HTN. According to the hypothesis put forward by Guyton, over 40 years ago, the control of BP in the steady-state and longer-term is critically dependent on renal mechanisms. In fact, almost all monogenic forms of HTN are driven by rare mutations in genes involved in salt handling in the distal nephron. It is therefore crucial to understand kidney DNA methylation changes that may drive gene expression in kidney and lead to HTN. Hypothesis: The central hypothesis underpinning this PhD thesis is that alterations in kidney specific DNA methylation plays a fundamental role in modulating gene expression changes involved in the regulation of BP and pathophysiology of EH. Aims: This PhD thesis focuses on characterising the role of DNA methylation in the hypertensive kidney using array and RNA-sequencing methods. Three major aims are addressed: • Aim 1: To characterise blood and kidney global DNA methylation dynamics and its functional role in the hypertensive population (Chapter 3). • Aim 2: To determine the role of genome-wide, loci specific DNA methylation in the hypertensive human kidney (Chapter 4). • Aim 3: To understand the relationship between DNA methylation and differential expression of genes associated with BP and HTN in the human kidney (Chapter 5). Results: In Aim 1 global DNA methylation changes were characterised in peripheral blood leukocyte and kidney DNA of the hypertensive (HT) population using he ELISA method. We found no association between HTN diagnosis and global methylation percentage in either peripheral blood leukocytes or kidney DNA. However, a negative correlation was found between global methylation and diastolic blood pressure (DBP), yet this relationship was not evident after adjustment for the effect of antihypertensive medication. Furthermore, we investigated the sensitivity of ELISA-based global methylation detection by calculating the percentage of global methylation in kidney using array based methods; the results were similar, demonstrating no association between HTN diagnosis and median kidney methylation
- Description: Doctor of Philosophy
- Authors: Wise, Ingrid
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Background: Hypertension (HTN) is a complex, multifactorial, quantitative trait under polygenic control that affects more than one billion people globally. Despite advances in our understanding of the pathophysiology of HTN and the implementation of more effective treatment and prevention strategies, HTN remains one of the world’s great public health problems. The accepted inference from genome-wide association studies (GWAS) is that the genetic code lays the foundation for transcriptomic changes and in turn physiological change. On the other side of the coin, environmental factors (smoking, diet, chemical exposure) can in turn affect DNA itself in genes relevant to blood pressure (BP). Variation in epigenetic forms of modification may thus explain additional phenotypic variation in BP and provide new clues to the physiological processes influencing its regulation. DNA methylation is one of these epigenetic mechanisms responsible for changes to gene expression, activated by interaction with environmental triggers. DNA methylation is a reversible epigenetic modifier of specific dinucleotide sites called CpGs, which consists of a transfer of a methyl group derived from S-adenosyl-L-methionine to position five of a cytosine ring, forming 5mC. Pathophysiologically, the kidney is known as the key organ of BP regulation and one of the most important contributors to HTN. According to the hypothesis put forward by Guyton, over 40 years ago, the control of BP in the steady-state and longer-term is critically dependent on renal mechanisms. In fact, almost all monogenic forms of HTN are driven by rare mutations in genes involved in salt handling in the distal nephron. It is therefore crucial to understand kidney DNA methylation changes that may drive gene expression in kidney and lead to HTN. Hypothesis: The central hypothesis underpinning this PhD thesis is that alterations in kidney specific DNA methylation plays a fundamental role in modulating gene expression changes involved in the regulation of BP and pathophysiology of EH. Aims: This PhD thesis focuses on characterising the role of DNA methylation in the hypertensive kidney using array and RNA-sequencing methods. Three major aims are addressed: • Aim 1: To characterise blood and kidney global DNA methylation dynamics and its functional role in the hypertensive population (Chapter 3). • Aim 2: To determine the role of genome-wide, loci specific DNA methylation in the hypertensive human kidney (Chapter 4). • Aim 3: To understand the relationship between DNA methylation and differential expression of genes associated with BP and HTN in the human kidney (Chapter 5). Results: In Aim 1 global DNA methylation changes were characterised in peripheral blood leukocyte and kidney DNA of the hypertensive (HT) population using he ELISA method. We found no association between HTN diagnosis and global methylation percentage in either peripheral blood leukocytes or kidney DNA. However, a negative correlation was found between global methylation and diastolic blood pressure (DBP), yet this relationship was not evident after adjustment for the effect of antihypertensive medication. Furthermore, we investigated the sensitivity of ELISA-based global methylation detection by calculating the percentage of global methylation in kidney using array based methods; the results were similar, demonstrating no association between HTN diagnosis and median kidney methylation
- Description: Doctor of Philosophy
First World War Avenues of Honour : Social history through the landscape
- Authors: Taffe, Michael
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis argues that avenues of honour were the first choice of memorial to the Great War created by Australians. Despite not being the first such avenue, the thesis argues that, by virtue of the massive amount of publicity it brought to focus on this form of memorial, the Ballarat Avenue of Honour was a significant cultural statement by Australians during the Great War. The Ballarat Avenue of Honour was inspirational and pivotal to the establishment of a movement that saw similar memorial avenues planted throughout Australia and also in the U.S.A., U.K., Canada and New Zealand. Using examples from municipal council minutes, correspondence and newspaper reports the spread of this form of memorial is followed from its infancy in South Australia through the Ballarat experience to Britain, North America and New Zealand. Following Australia‘s first plantings in 1915, there was a groundswell from many communities throughout Australia who adopted this form of memorialisation. Australian communities took control of their own need to honour their heroes, their local volunteers, in avenue of honour plantings. Following the example of Ballarat after 1917, this desire to plant memorial avenues became a movement. Examples of the growth of this memorial movement, while government aimed to control spending by curtailing ‗waste‘ on memorials, are outlined and analysed. The thesis also examines the symbolism of avenues against the perceived superior ‗worthiness‘ of later built memorials. By the time the movement declined in Australia, other countries were continued to plant avenues. The diminution, and eventual fall, from memory of many of these heritage landscapes is explored as a part of the politics of identity. In examining the arguments, the links between Ballarat‘s avenue and others throughout Australia, the respective Commonwealth countries as well as the U.S.A. are developed.
- Description: Doctor of Philosophy
- Authors: Taffe, Michael
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis argues that avenues of honour were the first choice of memorial to the Great War created by Australians. Despite not being the first such avenue, the thesis argues that, by virtue of the massive amount of publicity it brought to focus on this form of memorial, the Ballarat Avenue of Honour was a significant cultural statement by Australians during the Great War. The Ballarat Avenue of Honour was inspirational and pivotal to the establishment of a movement that saw similar memorial avenues planted throughout Australia and also in the U.S.A., U.K., Canada and New Zealand. Using examples from municipal council minutes, correspondence and newspaper reports the spread of this form of memorial is followed from its infancy in South Australia through the Ballarat experience to Britain, North America and New Zealand. Following Australia‘s first plantings in 1915, there was a groundswell from many communities throughout Australia who adopted this form of memorialisation. Australian communities took control of their own need to honour their heroes, their local volunteers, in avenue of honour plantings. Following the example of Ballarat after 1917, this desire to plant memorial avenues became a movement. Examples of the growth of this memorial movement, while government aimed to control spending by curtailing ‗waste‘ on memorials, are outlined and analysed. The thesis also examines the symbolism of avenues against the perceived superior ‗worthiness‘ of later built memorials. By the time the movement declined in Australia, other countries were continued to plant avenues. The diminution, and eventual fall, from memory of many of these heritage landscapes is explored as a part of the politics of identity. In examining the arguments, the links between Ballarat‘s avenue and others throughout Australia, the respective Commonwealth countries as well as the U.S.A. are developed.
- Description: Doctor of Philosophy
Gas chromatographic-mass spectrometry analysis of volatile organic compounds from cancer cell cultures - The effect of hypoxia
- Authors: Kalluri, Usha
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Early diagnosis of lung cancer improves patient outcomes which has led to a search for non-invasive diagnostic tests suitable for population screening. Volatile organic compounds (VOCs) in exhaled breath have shown potential, however, confirmation of the metabolic origins and disease specificity of candidate markers is required. Cell culture metabolomics can identify disease biomarkers and their origins. To date VOC profiles from in vitro cultured cancer cells have little similarity to cancer breath VOC profiles. In vivo, cancer cells experience hypoxia whereas in vitro cells are cultured under normoxic conditions. Since hypoxia influences cell metabolism, we hypothesize that cancer cells cultured under hypoxic conditions will have altered cell metabolism and produce VOC profiles more typical of cancer breathe. This study investigates the effect of hypoxia on metabolic reprogramming in A549 lung cancer cells cultured under standard normoxic (atmospheric oxygen) or hypoxic (2% oxygen) conditions. Results from quantitative RT-PCR demonstrated a significant upregulation in hypoxia of the glucose transporter (GLUT1) and the key TCA regulatory gene PDHK1, demonstrating that hypoxia plays a pivotal role in regulating metabolism in A549 cells. A ratio-metric assessment of Lipid Peroxidation (LPO) and the production of reactive oxygen species (ROS) showed an increase in LPO and a slight decrease in the production of ROS in hypoxic cultures, the combined effect of which may serve to equip the cells to adapt to and proliferate under low oxygen. Finally, the comparison of endogenous VOCs produced by A549 cells under hypoxic and normoxic conditions identified twelve VOCs unique to cells grown under hypoxic conditions including n-pentane, a marker of LPO and cancer, and 3-methyl hexane, which has been reported as a biomarker of cancer. This data is consistent with the hypothesis that a hypoxic tumour microenvironment may influence cell metabolism leading to a unique and diagnostic cancer VOC profile.
- Description: Doctor of Philosophy
- Authors: Kalluri, Usha
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Early diagnosis of lung cancer improves patient outcomes which has led to a search for non-invasive diagnostic tests suitable for population screening. Volatile organic compounds (VOCs) in exhaled breath have shown potential, however, confirmation of the metabolic origins and disease specificity of candidate markers is required. Cell culture metabolomics can identify disease biomarkers and their origins. To date VOC profiles from in vitro cultured cancer cells have little similarity to cancer breath VOC profiles. In vivo, cancer cells experience hypoxia whereas in vitro cells are cultured under normoxic conditions. Since hypoxia influences cell metabolism, we hypothesize that cancer cells cultured under hypoxic conditions will have altered cell metabolism and produce VOC profiles more typical of cancer breathe. This study investigates the effect of hypoxia on metabolic reprogramming in A549 lung cancer cells cultured under standard normoxic (atmospheric oxygen) or hypoxic (2% oxygen) conditions. Results from quantitative RT-PCR demonstrated a significant upregulation in hypoxia of the glucose transporter (GLUT1) and the key TCA regulatory gene PDHK1, demonstrating that hypoxia plays a pivotal role in regulating metabolism in A549 cells. A ratio-metric assessment of Lipid Peroxidation (LPO) and the production of reactive oxygen species (ROS) showed an increase in LPO and a slight decrease in the production of ROS in hypoxic cultures, the combined effect of which may serve to equip the cells to adapt to and proliferate under low oxygen. Finally, the comparison of endogenous VOCs produced by A549 cells under hypoxic and normoxic conditions identified twelve VOCs unique to cells grown under hypoxic conditions including n-pentane, a marker of LPO and cancer, and 3-methyl hexane, which has been reported as a biomarker of cancer. This data is consistent with the hypothesis that a hypoxic tumour microenvironment may influence cell metabolism leading to a unique and diagnostic cancer VOC profile.
- Description: Doctor of Philosophy
Green bonds : Do they bring sustainability to environmentally friendly projects?
- Authors: Nanayakkara, Madurika
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: This study was motivated by the urgent requirement to scale up the global green bond (GB) market to meet the trillion-dollar financial requirement of environmental resilience projects worldwide, and by the absence of prior scientific investigations to determine solutions to the GB market’s problems from different perspectives. Three empirical studies were conducted to provide a holistic view of the GB market. The first study investigated the perception gaps of different stakeholders in the GB market in terms of assessing the ‘greenness’ of projects funded through GBs, investors’ expectations of GB investments, and the factors hindering the growth of the GB market. A qualitative method was employed with document review, followed by interviews, a questionnaire survey and peer debriefing. The study found that both the demand and supply sides of the GB market are inadequate to meet the world’s green investment requirements. The main obstacles hindering the market growth are fear for greenwashing, definitions that lack clarity, the absence of large-scale issues, and the high costs associated with complex reporting processes and third-party certifications. The second study assessed the influence of GB principles on investor demand for GBs, using global GBs issued for the period 2007 to 2016. Bid–ask spread and yield spread were used to measure the investor demand. The results indicated a significant positive relationship between the degree of compliance and investor demand. The third study compared the credit spreads of corporate GBs and conventional bonds, measured by option-adjusted spread daily data for the period 2016 to 2017 worldwide. Hybrid method of panel data regression was employed to analyse the data, and found that GBs are traded at a premium in the world market, compared with conventional bonds. This thesis suggests several policy implications based on the findings of these studies to scale up the GB market as a new source of financing.
- Description: Doctor of Philosophy
- Authors: Nanayakkara, Madurika
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: This study was motivated by the urgent requirement to scale up the global green bond (GB) market to meet the trillion-dollar financial requirement of environmental resilience projects worldwide, and by the absence of prior scientific investigations to determine solutions to the GB market’s problems from different perspectives. Three empirical studies were conducted to provide a holistic view of the GB market. The first study investigated the perception gaps of different stakeholders in the GB market in terms of assessing the ‘greenness’ of projects funded through GBs, investors’ expectations of GB investments, and the factors hindering the growth of the GB market. A qualitative method was employed with document review, followed by interviews, a questionnaire survey and peer debriefing. The study found that both the demand and supply sides of the GB market are inadequate to meet the world’s green investment requirements. The main obstacles hindering the market growth are fear for greenwashing, definitions that lack clarity, the absence of large-scale issues, and the high costs associated with complex reporting processes and third-party certifications. The second study assessed the influence of GB principles on investor demand for GBs, using global GBs issued for the period 2007 to 2016. Bid–ask spread and yield spread were used to measure the investor demand. The results indicated a significant positive relationship between the degree of compliance and investor demand. The third study compared the credit spreads of corporate GBs and conventional bonds, measured by option-adjusted spread daily data for the period 2016 to 2017 worldwide. Hybrid method of panel data regression was employed to analyse the data, and found that GBs are traded at a premium in the world market, compared with conventional bonds. This thesis suggests several policy implications based on the findings of these studies to scale up the GB market as a new source of financing.
- Description: Doctor of Philosophy
Investigating bird responses to fire in the Heathy Dry Forests of Victoria, Australia
- Authors: Kuchinke, Diana
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Globally, forest birds are under pressure, from agriculture and urban development fragmenting the landscape. Adding to these pressures, changes in the patterns of global climate drivers give rise to an increase in the frequency of extreme weather events. In Victoria, Australia, changing weather conditions are resulting in increases in the frequency and extent of bushfires. Furthermore, prescribed burning is applied to the landscape in attempts to not only ameliorate the impacts from bushfire, but as part of a ‘pyrodiversity begets biodiversity’ protocol. These pressures all impact birds by reducing resources for: food, nesting and protection from predators. This thesis investigated bird responses to fire in the Heathy Dry Forests of Victoria, against variables of time-since-fire and fire frequency. Bird responses were modelled in terms of: community, foraging guilds and individual species. As a community, birds showed a resilience to both time since fire and fire frequency. Responses by foraging guilds and individual species highlighted some different responses. The common species from each foraging guild showed responses that broadly represent their guild. This thesis highlighted that an effective tool in adaptive management is to predict the trends of our common forest birds, as surrogates for entire bird communities, not just for fire responses, but for a broader reflection on the health of the landscape. The modelling of one species, the Laughing Kookaburra, showed a response to both time since fire and fire frequency, with a reduced abundance in post-fire new-growth vegetation. As this species is noted as being in decline down the east coast of Australia, it is flagged in this thesis as a species of concern. Further, this thesis investigated alpha and beta responses by the forest birds to prescribed burns of different severities. Results suggest that forest birds show little response to small prescribed burns in the landscape, regardless of severity. This may be a result of Heathy Dry Forests’ rapid regeneration post-fire. However, one species that exhibits site fidelity, the White-throated Treecreeper, left areas impacted by high severity prescribed burns. The White-throated Treecreeper’s response flagged the importance of tree hollows being maintained in the landscape, essential for the species that require hollows for roosting and nesting.
- Description: Doctor of Philosophy
- Description: Globally, forest birds are under pressure, from agriculture and urban development fragmenting the landscape. Adding to these pressures, changes in the patterns of global climate drivers give rise to an increase in the frequency of extreme weather events. In Victoria, Australia, changing weather conditions are resulting in increases in the frequency and extent of bushfires. Furthermore, prescribed burning is applied to the landscape in attempts to not only ameliorate the impacts from bushfire, but as part of a ‘pyrodiversity begets biodiversity’ protocol. These pressures all impact birds by reducing resources for: food, nesting and protection from predators. This thesis investigated bird responses to fire in the Heathy Dry Forests of Victoria, against variables of time-since-fire and fire frequency. Bird responses were modelled in terms of: community, foraging guilds and individual species. As a community, birds showed a resilience to both time since fire and fire frequency. Responses by foraging guilds and individual species highlighted some different responses. The common species from each foraging guild showed responses that broadly represent their guild. This thesis highlighted that an effective tool in adaptive management is to predict the trends of our common forest birds, as surrogates for entire bird communities, not just for fire responses, but for a broader reflection on the health of the landscape. The modelling of one species, the Laughing Kookaburra, showed a response to both time since fire and fire frequency, with a reduced abundance in post-fire new-growth vegetation. As this species is noted as being in decline down the east coast of Australia, it is flagged in this thesis as a species of concern. Further, this thesis investigated alpha and beta responses by the forest birds to prescribed burns of different severities. Results suggest that forest birds show little response to small rescribed burns in the landscape, regardless of severity. This may be a result of Heathy Dry Forests’ rapid regeneration post-fire. However, one species that exhibits site fidelity, the White-throated Treecreeper, left areas impacted by high severity prescribed burns. The White-throated Treecreeper’s response flagged the importance of tree hollows being maintained in the landscape, essential for the species that require hollows for roosting and nesting.
- Authors: Kuchinke, Diana
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Globally, forest birds are under pressure, from agriculture and urban development fragmenting the landscape. Adding to these pressures, changes in the patterns of global climate drivers give rise to an increase in the frequency of extreme weather events. In Victoria, Australia, changing weather conditions are resulting in increases in the frequency and extent of bushfires. Furthermore, prescribed burning is applied to the landscape in attempts to not only ameliorate the impacts from bushfire, but as part of a ‘pyrodiversity begets biodiversity’ protocol. These pressures all impact birds by reducing resources for: food, nesting and protection from predators. This thesis investigated bird responses to fire in the Heathy Dry Forests of Victoria, against variables of time-since-fire and fire frequency. Bird responses were modelled in terms of: community, foraging guilds and individual species. As a community, birds showed a resilience to both time since fire and fire frequency. Responses by foraging guilds and individual species highlighted some different responses. The common species from each foraging guild showed responses that broadly represent their guild. This thesis highlighted that an effective tool in adaptive management is to predict the trends of our common forest birds, as surrogates for entire bird communities, not just for fire responses, but for a broader reflection on the health of the landscape. The modelling of one species, the Laughing Kookaburra, showed a response to both time since fire and fire frequency, with a reduced abundance in post-fire new-growth vegetation. As this species is noted as being in decline down the east coast of Australia, it is flagged in this thesis as a species of concern. Further, this thesis investigated alpha and beta responses by the forest birds to prescribed burns of different severities. Results suggest that forest birds show little response to small prescribed burns in the landscape, regardless of severity. This may be a result of Heathy Dry Forests’ rapid regeneration post-fire. However, one species that exhibits site fidelity, the White-throated Treecreeper, left areas impacted by high severity prescribed burns. The White-throated Treecreeper’s response flagged the importance of tree hollows being maintained in the landscape, essential for the species that require hollows for roosting and nesting.
- Description: Doctor of Philosophy
- Description: Globally, forest birds are under pressure, from agriculture and urban development fragmenting the landscape. Adding to these pressures, changes in the patterns of global climate drivers give rise to an increase in the frequency of extreme weather events. In Victoria, Australia, changing weather conditions are resulting in increases in the frequency and extent of bushfires. Furthermore, prescribed burning is applied to the landscape in attempts to not only ameliorate the impacts from bushfire, but as part of a ‘pyrodiversity begets biodiversity’ protocol. These pressures all impact birds by reducing resources for: food, nesting and protection from predators. This thesis investigated bird responses to fire in the Heathy Dry Forests of Victoria, against variables of time-since-fire and fire frequency. Bird responses were modelled in terms of: community, foraging guilds and individual species. As a community, birds showed a resilience to both time since fire and fire frequency. Responses by foraging guilds and individual species highlighted some different responses. The common species from each foraging guild showed responses that broadly represent their guild. This thesis highlighted that an effective tool in adaptive management is to predict the trends of our common forest birds, as surrogates for entire bird communities, not just for fire responses, but for a broader reflection on the health of the landscape. The modelling of one species, the Laughing Kookaburra, showed a response to both time since fire and fire frequency, with a reduced abundance in post-fire new-growth vegetation. As this species is noted as being in decline down the east coast of Australia, it is flagged in this thesis as a species of concern. Further, this thesis investigated alpha and beta responses by the forest birds to prescribed burns of different severities. Results suggest that forest birds show little response to small rescribed burns in the landscape, regardless of severity. This may be a result of Heathy Dry Forests’ rapid regeneration post-fire. However, one species that exhibits site fidelity, the White-throated Treecreeper, left areas impacted by high severity prescribed burns. The White-throated Treecreeper’s response flagged the importance of tree hollows being maintained in the landscape, essential for the species that require hollows for roosting and nesting.
Investigating the impact of participation in alternative education from a positive youth development perspective : A case study of the School for Student Leadership
- Authors: Joyce, Susan
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: The School for Student Leadership (SSL) has existed since 2001 as an alternative residential educational setting for Year 9 students in Victoria, Australia. It was designed in response to growing calls for more effective ways of engaging middle school students. A review of the literature illustrated a dearth of research regarding alternative programs and schools, particularly from a positive youth development (PYD) perspective, and relating to long term effects of participation. This study investigated student participants’ perceived development in relation to the Five Cs - Confidence, Competence, Character, Connection and Care, concepts derived from the framework of PYD. It also examined differences in perceptions of students attending a shorter five-week program, compared to the standard nine-week program, as well as differences between male and female participants. This case study was undertaken utilising a mixed methods approach, using pre and post program surveys and interviews. Between 2013 and 2014, 385 students were surveyed and 58 interviews conducted over nine program offerings. The participants were then followed up one year post program, with 172 surveys returned and 14 interviews conducted. With the assistance of computer software programs, both the quantitative and qualitative data was analysed and then triangulated to form the findings. Participants’ ratings for each of the Five Cs were higher at the end of the program, and effect sizes, though generally small, when combined with the qualitative data indicated the program as having a significant positive impact, although this diminished slightly one year post program. Little discernible difference was found between the five- and the nine-week programs, and only slight differences between the two genders. The set of recommendations that emanated from this research should be of assistance for both the SSL and other schools, particularly in relation to enhancing attributes such as the Five Cs.
- Description: Doctor of Philosophy
- Authors: Joyce, Susan
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: The School for Student Leadership (SSL) has existed since 2001 as an alternative residential educational setting for Year 9 students in Victoria, Australia. It was designed in response to growing calls for more effective ways of engaging middle school students. A review of the literature illustrated a dearth of research regarding alternative programs and schools, particularly from a positive youth development (PYD) perspective, and relating to long term effects of participation. This study investigated student participants’ perceived development in relation to the Five Cs - Confidence, Competence, Character, Connection and Care, concepts derived from the framework of PYD. It also examined differences in perceptions of students attending a shorter five-week program, compared to the standard nine-week program, as well as differences between male and female participants. This case study was undertaken utilising a mixed methods approach, using pre and post program surveys and interviews. Between 2013 and 2014, 385 students were surveyed and 58 interviews conducted over nine program offerings. The participants were then followed up one year post program, with 172 surveys returned and 14 interviews conducted. With the assistance of computer software programs, both the quantitative and qualitative data was analysed and then triangulated to form the findings. Participants’ ratings for each of the Five Cs were higher at the end of the program, and effect sizes, though generally small, when combined with the qualitative data indicated the program as having a significant positive impact, although this diminished slightly one year post program. Little discernible difference was found between the five- and the nine-week programs, and only slight differences between the two genders. The set of recommendations that emanated from this research should be of assistance for both the SSL and other schools, particularly in relation to enhancing attributes such as the Five Cs.
- Description: Doctor of Philosophy
Lime stabilisation of an Australian silty clay and its application in construction of excavation retaining walls by cutter soil mixing
- Authors: Ranjbar Pouya, Kaveh
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Coode Island Silt (CIS) is one of the predominant geological units in Melbourne, Australia. Having high compressibility and low shear strength, CIS is considered a problematic soft soil that challenges the construction of infrastructure in the region. To tackle such challenges, one practical approach is the application of ground improvement techniques such as in situ soil mixing. This PhD study focuses on the application of Cutter Soil Mixing (CSM) for the construction of excavation retaining walls in CIS. Although cement is widely used in most CSM projects, this study investigates the suitability of different lime types available in the Australian market as a potential alternative to cement for the stabilisation of CIS. To investigate the effect of lime stabilisation, a comprehensive geotechnical characterisation of untreated and lime treated CIS is performed. Four different lime types are used: agricultural lime, quicklime, hydrated lime and slag lime. Based on the results obtained from strength tests, slag lime was found to be the most effective among the four types that were tested. The optimum slag lime to CIS ratio is then found for the construction of retaining walls in CIS. Having the geotechnical characterisation of untreated and treated CIS from the laboratory experiments, a series of two-dimensional and three-dimensional finite element method (FEM) analyses were conducted to investigate the applicability and reliability of the selected mixing ratio for the construction of CSM excavation retaining walls in CIS. A nonlinear constitutive soil model was employed, calibrated and verified to be used in FEM analyses to investigate both the stability factor of safety and excavation-induced deformations. The results obtained for both undrained and fully coupled flow deformation analyses prove that CSM panels can be constructed by mixing slag lime and CIS to act as retaining walls to allow for deep excavation in CIS.
- Description: Doctor of Philosophy
- Authors: Ranjbar Pouya, Kaveh
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Coode Island Silt (CIS) is one of the predominant geological units in Melbourne, Australia. Having high compressibility and low shear strength, CIS is considered a problematic soft soil that challenges the construction of infrastructure in the region. To tackle such challenges, one practical approach is the application of ground improvement techniques such as in situ soil mixing. This PhD study focuses on the application of Cutter Soil Mixing (CSM) for the construction of excavation retaining walls in CIS. Although cement is widely used in most CSM projects, this study investigates the suitability of different lime types available in the Australian market as a potential alternative to cement for the stabilisation of CIS. To investigate the effect of lime stabilisation, a comprehensive geotechnical characterisation of untreated and lime treated CIS is performed. Four different lime types are used: agricultural lime, quicklime, hydrated lime and slag lime. Based on the results obtained from strength tests, slag lime was found to be the most effective among the four types that were tested. The optimum slag lime to CIS ratio is then found for the construction of retaining walls in CIS. Having the geotechnical characterisation of untreated and treated CIS from the laboratory experiments, a series of two-dimensional and three-dimensional finite element method (FEM) analyses were conducted to investigate the applicability and reliability of the selected mixing ratio for the construction of CSM excavation retaining walls in CIS. A nonlinear constitutive soil model was employed, calibrated and verified to be used in FEM analyses to investigate both the stability factor of safety and excavation-induced deformations. The results obtained for both undrained and fully coupled flow deformation analyses prove that CSM panels can be constructed by mixing slag lime and CIS to act as retaining walls to allow for deep excavation in CIS.
- Description: Doctor of Philosophy