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Hyperbolic smoothing in nonsmooth optimization and applications

  • Authors: Al Nuaimat, Alia
  • Date: 2014
  • Type: Text , Thesis , PhD
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  • Description: Nonsmooth nonconvex optimization problems arise in many applications including economics, business and data mining. In these applications objective functions are not necessarily differentiable or convex. Many algorithms have been proposed over the past three decades to solve such problems. In spite of the significant growth in this field, the development of efficient algorithms for solving this kind of problem is still a challenging task. The subgradient method is one of the simplest methods developed for solving these problems. Its convergence was proved only for convex objective functions. This method does not involve any subproblems, neither for finding search directions nor for computation of step lengths, which are fixed ahead of time. Bundle methods and their various modifications are among the most efficient methods for solving nonsmooth optimization problems. These methods involve a quadratic programming subproblem to find search directions. The size of the subproblem may increase significantly with the number of variables, which makes the bundle-type methods unsuitable for large scale nonsmooth optimization problems. The implementation of bundle-type methods, which require the use of the quadratic programming solvers, is not as easy as the implementation of the subgradient methods. Therefore it is beneficial to develop algorithms for nonsmooth nonconvex optimization which are easy to implement and more efficient than the subgradient methods. In this thesis, we develop two new algorithms for solving nonsmooth nonconvex optimization problems based on the use of the hyperbolic smoothing technique and apply them to solve the pumping cost minimization problem in water distribution. Both algorithms use smoothing techniques. The first algorithm is designed for solving finite minimax problems. In order to apply the hyperbolic smoothing we reformulate the objective function in the minimax problem and study the relationship between the original minimax and reformulated problems. We also study the main properties of the hyperbolic smoothing function. Based on these results an algorithm for solving the finite minimax problem is proposed and this algorithm is implemented in GAMS. We present preliminary results of numerical experiments with well-known nonsmooth optimization test problems. We also compare the proposed algorithm with the algorithm that uses the exponential smoothing function as well as with the algorithm based on nonlinear programming reformulation of the finite minimax problem. The second nonsmooth optimization algorithm we developed was used to demonstrate how smooth optimization methods can be applied to solve general nonsmooth (nonconvex) optimization problems. In order to do so we compute subgradients from some neighborhood of the current point and define a system of linear inequalities using these subgradients. Search directions are computed by solving this system. This system is solved by reducing it to the minimization of the convex piecewise linear function over the unit ball. Then the hyperbolic smoothing function is applied to approximate this minimization problem by a sequence of smooth problems which are solved by smooth optimization methods. Such an approach allows one to apply powerful smooth optimization algorithms for solving nonsmooth optimization problems and extend smoothing techniques for solving general nonsmooth nonconvex optimization problems. The convergence of the algorithm based on this approach is studied. The proposed algorithm was implemented in Fortran 95. Preliminary results of numerical experiments are reported and the proposed algorithm is compared with an other five nonsmooth optimization algorithms. We also implement the algorithm in GAMS and compare it with GAMS solvers using results of numerical experiments.
  • Description: Doctor of Philosophy

Kemo Sabe : Tonto as a developing construction of the Indian character type

  • Authors: Moll, Nicholas
  • Date: 2014
  • Type: Text , Thesis , PhD
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  • Description: At the opening of each episode of The Lone Ranger radio series, audiences are invited to “return with us now to those thrilling days of yesteryear”. From 1933 through to 2013 productions of The Lone Ranger media franchise have continued to extend this invitation. The evocation of the past through The Lone Ranger franchise includes Tonto: the masked man’s Indian sidekick. Tonto has remained an element of the franchise since the inception of The Lone Ranger and the development of Tonto presents an intriguing map of changing Indian characterization across the twentieth-century. This study argues that Tonto has developed as the masked man’s foil to incorporate colonial violence and Anglo-American culpability into The Lone Ranger narratives. In doing so, this thesis notes that Tonto’s assimilation within narratives of The Lone Ranger can be read like a parable, presenting a model of appropriate social responses for the interrelation of races through the masked man and Tonto’s partnership. The structure and style of Tonto’s assimilation develops gradually in the franchise over the course of the twentieth-century. Initially Tonto’s assimilation suggested a Romanticized future for the Indian following colonization. However, later productions of The Lone Ranger juxtapose assimilation with extermination. In analysing the development of Tonto, this thesis examines six features of the character. The first three are foundation concepts consisting of the idea of the Indian, the Western genre and franchise theory and development. The second three are constant facets of characterization comprised of Tonto’s status as an Indian, the recurring theme of Manifest Destiny in The Lone Ranger texts, and the growth of Tonto parallel to activism of the 1960s and 1970s. This thesis contributes to knowledge as the first study of Tonto as an ongoing development rather than a static characterization discussed in broad terms.
  • Description: Doctor of Philosophy

Learning to Lead : The social nature of women's development in sport leadership

  • Authors: Brown, Suzanne
  • Date: 2014
  • Type: Text , Thesis , PhD
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  • Description: Despite the ubiquitous political and educational strategies aimed at redressing gender inequality in sport in Australia for the past 30 years, the number of women in sport in decision-making and leadership positions has remained low when compared to men. While a number of studies have explored women’s under-representation in sport leadership roles, there is limited understanding of how women practice sport leadership and how they develop as leaders. To address this gap in the literature, this study took a humanistic approach to account for, and consider, the nature of experience and the influence of context. This study sought to provide a more personal, nuanced, and socially situated understanding of how women practiced and learned to lead in sport. An interpretive qualitative research design framed by a social constructivist lens was used for this study to examine 23 women’s accounts of what constituted and framed their leadership practices, including how they learned leadership from their engagement in day-to-day social practices and life experiences over time. Data for this study were generated through in-depth, semi-structured interviews conducted with each of the participants over a period of two years. A multi-case study approach was used to analyse the data. It was found that the participants’ leadership practice featured distinctive feminine characteristics. However, for those participants at the elite level their approaches to leadership were characterised by interaction that seemed to be traditional masculine features of leadership with the participants’ “core” feminine approaches to leadership. The participants’ leadership practice focused on social interaction and relationship building underpinned by a strong sense of moral and ethical values. Key features included collaborative decision-making, taking a team-oriented approach, using open dialogue, valuing relationships and caring about others, and positive modelling. The model of authentic leadership offered a useful way of conceptualising how the participants’ approached their practice of leadership. An examination of the participants’ accounts of their experiences of the ways they learned their leadership highlighted that leadership development for these women was a relational and social process of learning over a lifelong journey that was influenced by individual, personal experience situated within larger socio-cultural contexts. The relational nature of the participants’ learning of leadership was fundamentally connected to, and drawn from their interactions and interplay within their day-to-day social practices and life experiences from their early childhood through to their adulthood. The findings of study revealed that a range of past and present experiences and social factors influenced and shaped the participants’ values and beliefs about their leadership practice such as the development of their awareness and self-belief in their ability, the value of relationship building, and development of strength of character associated with resilience. This study also identified the significance of the informal social nature of the development of leadership through the participants’ “lived” experiences but also recognised the importance of some formal learning in developing the human capital aspects of the participants’ leadership. Findings from this study have contributed to the relatively small body of literature concerned with the examination of leadership practice and learning leadership for women in a context of sport. This study has drawn attention to the different sets of relationships that women draw on to develop their leadership practice from a young age through to their adulthood, and has highlighted the multidimensional role of relational dynamics in the construction of leadership. This study has also illustrated the importance of experiential and situated learning that occurs during the formative years through to adulthood in terms of developing women’s social skills and social awareness. These findings have implications for the way in which women’s sport leadership practice is viewed and encourages a rethinking on how affirmative action policies address the leadership developed for women in sport in Australia.
  • Description: Doctor of Philosophy

Nonsmooth and derivative-free optimization based hybrid methods and applications

  • Authors: Long, Qiang
  • Date: 2014
  • Type: Text , Thesis , PhD
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  • Description: "In this thesis, we develop hybrid methods for solving global and in particular, nonsmooth optimization problems. Hybrid methods are becoming more popular in global optimization since they allow to apply powerful smooth optimization techniques to solve global optimization problems. Such methods are able to efficiently solve global optimization problems with large number of variables. To date global search algorithms have been mainly applied to improve global search properties of the local search methods (including smooth optimization algorithms). In this thesis we apply rather different strategy to design hybrid methods. We use local search algorithms to improve the efficiency of global search methods. The thesis consists of two parts. In the first part we describe hybrid algorithms and in the second part we consider their various applications." -- taken from Abstract.
  • Description: Operational Research and Cybernetics

Partnership rhetoric and risk realities : the implications of risk in government/non-government family services partnerships

  • Authors: McDonald, Kelsey
  • Date: 2014
  • Type: Text , Thesis , PhD
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  • Description: "This empirical study examined risk transfer from the government to the non-government sector within a public/non-profit child and family services delivery partnership. The focus of the investigation was to determine if risk had been transferred from the government to the non-government partner, and how this had impacted on welfare practice, service provision and outcomes for service users. A case study of a 2007 government/non-government child protection and child and family services partnership in the state of Victoria, Australia provided the context for the study. The research framework involved a predominantly qualitative methodology, with the researcher embedded at two Victorian Community Service Organisations (CSOs) for a 12-month period." -- Taken from Abstract.
  • Description: Doctorate of Philosopy

The physiology of road cycling : New testing and training methodologies for competitive cyclists

  • Authors: Clark, Bradley
  • Date: 2014
  • Type: Text , Thesis , PhD
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  • Description: Objective: The objective of this project is to describe and test the efficacy of new testing and training techniques for competitive cyclists. Methods: Physiological variables and cycling performance were measured during a graded exercise test (GXT) and a novel, computer-simulated, variable gradient 20-km cycling time-trial. Initially, data collected from the time-trial and GXT were used to establish the reliability of the time-trial, determine the laboratory correlates of hilly cycling performance and examine the pacing pattern during hilly cycling performance. Then, results from a series of GXT’s and time-trials were used to establish the effects of a brief period of overload training on the physiology and performance of competitive cyclists. Results: Power output and performance time measured during a computer simulated 20-km variable gradient cycling test were reliable, however reliability diminished with increasing time between trials. Performance in variable gradient time-trial correlated strongly with absolute measures of physiological variables; however the strength of correlations increased when variables were measured relative to body mass. Power output was highest during the first four and last two kilometres of a variable gradient time-trial. Additionally, there were large differences in power output between consecutive one kilometre segments throughout the trial, particularly when the difference in gradient between segments was greater. Performance in the variable gradient time-trial improved substantially following a brief period of overload training. Performance improvement corresponded with adaptation in important physiological determinants of cycling performance, namely maximal oxygen uptake, lactate threshold and gross efficiency. Conclusions: Variable gradient, cycling time-trial tests can be used to detect meaningful changes in performance, evoke dynamic distribution of power output and are best suited to cyclists who produce high power outputs relative to body mass. The current project also determined that a brief period of overload training induces physiological adaptation and substantial improvement in cycling performance in competitive cyclists. Sport scientists, coaches and cyclists can use this information to determine the testing and training techniques used in preparation for competition.
  • Description: Doctor of Philosophy

Why firms in China go green and how they market green?

  • Authors: Song-Turner, Helen
  • Date: 2014
  • Type: Text , Thesis , PhD
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  • Description: Since the late 1970s China has strived to build a globally competitive market economy based on a range of industry sectors, focusing on manufacturing and allied industries. By 2014 the size of China’s economy is second only to that of the United States of America. A challenge in this context and situation—where economic growth is still a key area of policy focus for the government—is dealing with associated environmental matters and issues. By the turn of the 21st Century, environmental issues were receiving an unprecedented degree of attention from the Chinese Government, and one of the subsets of this issue is the concept of green marketing. A question arises regarding the possibilities of successful growing firms in China applying the concepts, principles and practices which embody green marketing within a rubric and context of sustained economic development. To gain a deep understanding of ways in which the concepts, applications and conditions of green marketing actually work in China, this research explores why firms in China go green and how they market their green products and services in China using an emic approach that emphasizes an indigenous, within culture perspective of firms’ behaviour in the Chinese context. Related to the research question this research explores a range of possible motivating factors and ascertains features of key influential stakeholders which might well influence firms’ green marketing approaches and practices in China. These firms are exceptional in the way they have addressed green marketing. The research undertaken seeks to identify ways in which these factors translate in marketing terms within a green marketing paradigm. Given that green marketing is arguably where economic development and environmental matters tend to interact and intersect within a market economy, this research provides insights to how sustainable Chinese firms deal with this complex and important issue. The use of a case study approach, across a range of industry sectors and in a variety of locations in China, provides depth and realism to this research. The result of this research contribute significantly to the understanding of how Chinese managers perceive ecological sustainability and expand firm stakeholder theory by identifying key influential stakeholders in proactive green decisions. The ways in which firms define and identify key influential stakeholders in their green decisions are influenced by resource dependency, the institutional power of the stakeholders, and moderated by firm’s characteristics and life cycle stages. Firms operating in a strong government-driven setting derive four conceptual green motivations—philosophical and social responsibility, management of risk reduction, competition pressure, and special events— that offer insights on understanding firms’ green behaviours and green orientations in China.

A conceptual model of physical performance in Australian Football

  • Authors: Mooney, Mitchell
  • Date: 2013
  • Type: Text , Thesis , PhD
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  • Description: Objective: The objective of this project was to identify the relative influence of valid physical parameters to elite Australian Football performance. Methods: Data was collected on match performance variables (i.e. coaches’ votes, number of ball disposals, champion data rank), match exercise intensity measures (m∙min-1, m∙min-1 above and below 15 km∙h-1 and Load™∙min-1) and physical capacities (yo-yo intermittent recovery test level 2, maximum oxygen uptake, running economy, relative aerobic intensity, maximal aerobic speed and maximal accumulated oxygen deficit) on elite and recreational Australian footballers. These variables were modelled to determine the logical sequence and relative importance towards match performance. Results: The results indicate a sequential physical path to Australian Football performance. The yo-yo intermittent recovery test (level 2) performance influenced match exercise intensity (m∙min-1 >15 km∙h-1& Load™∙min-1) which in turn, affected Australian Football performance (number of ball disposals and coaches’ votes). This sequence was altered by experience, playing position and neuromuscular fatigue. The number of interchange rotations also influenced match exercise intensity throughout the match. Furthermore, the yo-yo intermittent recovery test (level 2) was found to be determined by a complex interaction of physical capacities. However, yo-yo intermittent recovery (level 2) performance was most influenced by maximum oxygen uptake, relative aerobic intensity and maximum aerobic speed. Conclusion: This dissertation showed Australian Football performance is a complex and dynamic system influenced by many variables interacting with each other in a sequential path. Sports scientists and coaches may utilise this information as a framework to evaluate Australian Football performance matches.
  • Description: Doctor of Philosophy

An investigation into the agronomic factors affecting sustainability, surface hardness and rotational traction on community-level football grounds during drought conditions.

  • Authors: Ford, Phillip
  • Date: 2013
  • Type: Text , Thesis , PhD
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  • Description: Excessive hardness and rotational traction are the factors most associated with non-contact, ground-related injury risk in football. Irrigation has the greatest influence on surface hardness, and also in determining the turfgrass species that can be sustained. However, irrigation is prohibited on many Australian community-level grounds during drought. This thesis investigated the influence of various agronomic factors on surface hardness and on rotational traction, with the aim of devising strategies to reduce ground-related injury risk in drought conditions. In replicated plots tested over a drought period, Clegg hardness values on a football ground peaked at 160 gravities when turfgrass coverage was present, compared to values in excess of 200 gravities when turf coverage was absent. If the Clegg threshold was set at 160 g for community-level football, many grounds would stay open for play provided they sustained turfgrass coverage. In southern mainland Australia during drought and without irrigation, only a drought-resistant species such as couchgrass (Cynodon dactylon and hybrids) could do this. However, couchgrass has been linked by past epidemiological evidence to a higher risk of knee injury than perennial ryegrass (Lolium perenne), which was attributed to couchgrass having a higher rotational traction. In data presented in this thesis, perennial ryegrass actually had significantly higher rotational stiffness than couchgrass on four out of eight assessment dates. Consequently, there appears no reason to favour perennial ryegrass and to recommend against the use of couchgrass for reasons concerning rotational traction. Furthermore, the largest range in rotational traction was between areas of full grasscover compared to denuded areas. The thesis concluded that the ability to sustain turfgrass coverage provided the most effective agronomic solution for moderating both hardness and rotational traction on community-level football fields, and that a turfgrass species should be selected primarily on its ability to best sustain that coverage.
  • Description: Doctor of Philosophy

Broadening the concept of school: how a re-configuration of school must be inclusive of students who are "put at" a disadvantage

  • Authors: Peters, Edward (Keith)
  • Date: 2013
  • Type: Text , Thesis , PhD
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  • Description: This thesis critically examines how students enrolled in state-funded schools can be ‘put at’ a disadvantage. I do this through examining two techniques of exclusion that stimulate student disconnection from school: first, the ways in which standards-based and performativity-driven learning outcomes are implemented to shape how student success is determined. Secondly, I examine how discourses around power control curriculum and student identity instil monological learning structures that normalises standards-based learning outcomes. Challenging this, I allow the voices of my co-researchers, the students in my thesis, to speak back to confront these school-based policies that allow disconnection to occur. Examining school policy and student voice at the point where they intersect allowed me to undertake an evaluation of how schools adversely affect students, and what students say they want from their experience of schooling. The final theme I develop is based on student and agency worker voice and what they say school-based learning should become. Relational learning and learning that develops students ethically emerged as fundamental strengths of what enriching learning transactions should look like. I argue that creating relational learning spaces develop challenging environments that can lead students to ethically understand their identity within complex social and cultural lifestyles. I argue that the ways in which schools are organised to administer time and space must be radically overhauled if this is to be achieved.
  • Description: Doctor of Philosophy

Exploring resilience engineering through the presciption and practice of Safe Work Method Statements in the Victorian Construction Industry

  • Authors: Pillay, Manikam
  • Date: 2013
  • Type: Text , Thesis , PhD
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  • Description: This study investigated whether safe work method statements (SWMS) enhance or hinder resilience engineering (RE) as a health and safety management strategy in the Victorian construction industry. It is an important study because SWMS have been legislated by the federal and state governments as a fundamental risk control strategy for high-risk construction work; yet there is little empirical evidence to support this policy decision. Research on safety rules and procedures (to which SWMS can be associated) suggests they are not followed to the letter but adapted to suit context, and this adaptation is an important aspect of RE, a recent innovation in health and safety management.
  • Description: Doctor of Philosophy

Internet banking fraud detection using prudent analysis

  • Authors: Maruatona, Omaru
  • Date: 2013
  • Type: Text , Thesis , PhD
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  • Description: The threat posed by cybercrime to individuals, banks and other online financial service providers is real and serious. Through phishing, unsuspecting victims’ Internet banking usernames and passwords are stolen and their accounts robbed. In addressing this issue, commercial banks and other financial institutions use a generically similar approach in their Internet banking fraud detection systems. This common approach involves the use of a rule-based system combined with an Artificial Neural Network (ANN). The approach used by commercial banks has limitations that affect their efficiency in curbing new fraudulent transactions. Firstly, the banks’ security systems are focused on preventing unauthorized entry and have no way of conclusively detecting an imposter using stolen credentials. Also, updating these systems is slow and their maintenance is labour-intensive and ultimately costly to the business. A major limitation of these rule-bases is brittleness; an inability to recognise the limits of their knowledge. To address the limitations highlighted above, this thesis proposes, develops and evaluates a new system for use in Internet banking fraud detection using Prudence Analysis, a technique through which a system can detect when its knowledge is insufficient for a given case. Specifically, the thesis proposes the following contributions:
  • Description: Doctor of Philosophy

Legitimising harm : A critical ethnography of gambling in a community

  • Authors: Greenslade, Deborah
  • Date: 2013
  • Type: Text , Thesis , PhD
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  • Description: This thesis reports on a community study which explored the relationship between a small rural community and its club based poker machines. That enquiry aimed to broaden the general research focus from the dominant conceptualisation of individual gambling pathology to a community-level analysis. The theoretical and epistemological stance was also shifted, away from positivism (with its focus on measurable cause/effects), towards a critical constructionist approach. Employing ethnography, the research comprised extended community engagement, observation, document analysis and 51 individual interviews. Critical theory was applied to issues of ideology, discourse and power associated with poker machine gambling within the macro sociopolitical and local community contexts. The study found that, despite significant opposition, poker machines inveigled their way into this community with the support of powerful economic and political forces and influential club members. Location of the machines within an established club embedded them within networks of community relationships. Disbursement of community benefit ensnared many community members as beneficiaries of poker machine losses and rendered them complicit in gambling harms. The research identified that at times community ideology and interests acted as a powerful force against the establishment and expansion of poker machine gambling. Conversely, community ideology and interests also acted to legitimate the presence and operation of poker machines and to suppress opposition. This reflects the complex and contested nature of the construct of community. Reproduction of dominant gambling discourses, including those which frame gambling harm as pathology and an issue of individual responsibility, operate to conceal and condone gambling harms. These discourses marginalise and disempower community members harmed by gambling, while legitimating the club’s deployment of poker machines. This has helped to maintain existing arrangements and to support the shared and powerful interests of the state, the gambling industry, and venues.
  • Description: Doctor of Philosophy

The presence and role of Thiamine and Riboflavin in the malting and brewing industries

  • Authors: Hucker, Barry
  • Date: 2013
  • Type: Text , Thesis , PhD
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  • Description: Thiamine and riboflavin vitamers are present in a wide range of foods including beer. They play critical roles in a variety of enzymatic complexes and can promote and maintain metabolism. Currently, the presence and role of these vitamers in the malting and brewing industry has not been widely explored. This research has investigated the effects of various malting and brewing processes on the final thiamine and riboflavin vitamer content of finished beer. In order to achieve this, a highly accurate and reproducible HPLC (spike recovery > 95 %; RSD < 5.0 %) method was developed that allowed the separation of thiamine diphosphate (TDP), thiamine monophosphate (TMP), thiamine, riboflavin 5-phosphate (FMN) and riboflavin in various sample matrices. This method was utilised to determine the vitamer content of various cereals and malts and it was found that malting vastly alters the thiamine content of malted barley, while it has minimal effect on riboflavin content. When malted barley is roasted, all vitamers are rapidly degraded. The mashing process releases the various vitamers into a solution and this release is dependent on temperature and enzymatic activity, while wort boiling significantly reduces the vitamer content of the wort. During fermentation, the thiamine content of wort is quickly utilised within the first six hours of standard fermentations and the uptake of this vitamin is not affected by increases in wort gravity. Meanwhile riboflavin is only poorly utilised during these fermentations. Post-fermentative additives, such as the addition of tannic acid and potassium metabisulphite, negatively affect the vitamin content of the final product while phosphorylated forms of these vitamins are greatly affected by the addition of many post-fermentative processing aids/additives. The presence of both thiamine and riboflavin can enhance the spoilage of beer by known brewery spoilage organisms, and the incorrect storage of bottle-conditioned beer can negatively affect the vitamin and organoleptic properties of the final product. These various steps involved in the production of beer greatly affect the final vitamin content, and this knowledge helps to explain the large variation in the thiamine and riboflavin vitamer content of a survey of 204 commercially available beers. This survey concluded that despite the large variations within particular styles of beer, lagers contain the least amount of thiamine compared to ales, stout/porters and wheat beers. However the average riboflavin content of the tested beers was statistically similar (p = 0.608) across all of the styles. This is due to the limited utilisation of this vitamin during fermentations.
  • Description: Doctor of Philosophy

An identification of the meanings(s) of 'development' in a Chinese village context : The first piece of a jigsaw puzzle

  • Authors: Roy, Cameron
  • Date: 2012
  • Type: Text , Thesis , PhD
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  • Description: This thesis examines the meaning(s) of ‘development’ within a rural village in Sichuan province, China... Importantly, this thesis is a unique snapshot account containing grassroots stories about what development means from the voice and perspective of average Han villagers in a single village in contemporary rural China. (Taken from Abstract)
  • Description: Doctor of Philosophy

Consultation and organisational maturity in the Victorian construction industry

  • Authors: Ayers, Gerard
  • Date: 2012
  • Type: Text , Thesis , PhD
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  • Description: Consultation is generally acknowledged both in Australia and internationally, as being essential if high levels of occupational health and safety (OHS) are to be achieved and maintained. In Victoria, such is the recognition of the important role that consultation plays in OHS, that it is mandated under the Victorian OHS regulatory framework. Indeed, all Australian OHS statutes now make provision, to varying degrees, for consultation to occur when dealing with OHS matters. This is principally conducted through OHS representatives and OHS committees. However, there is a growing body of opinion which raises concerns over whether such legislative provisions that provide for OHS consultation, is sufficiently adequate to ensure that the consultation is both meaningful and effective in terms of OHS outcomes. If this is the case, what might be missing or lacking from the consultation process, especially in hazardous and dangerous industries where OHS success would appear to be imperative? The Victorian construction industry, like the construction industry in general, is acknowledged for its dangerous and hazardous nature. It has a large transitory workforce with little permanent job security and often suffers from a multifarious and disjointed work organisation structure. Such features tend to work against an environment that openly recognises and encourages meaningful and effective consultation. These conditions also tend to confound the development of any kind of social and positive learning and communicative culture within the industry, leading to an underutilization of the knowledge and skill contained within the workforce. As well as failing to bring to fruition the full participation of workers in the management of OHS, the underutilization of knowledge and skill is potentially one of the largest hidden costs that an organisation may incur. The notion of organisational and cultural maturity is acknowledged both internationally and in Australia as a useful concept that can assist organisations in achieving higher standards and levels of OHS. This is especially so in high risk and hazardous industries such as the petrochemical, oil refinery and aviation industries. However, organisational and cultural maturity is arguably a relatively new and under-researched construct in the Victorian building and construction industry, while the concept of consultation within both the industry and the organisational maturity paradigm has not yet been sufficiently explored. The role that moral and ethical principles play in consultation is now beginning to emerge and gain wider recognition within the literature. This research project set out to examine how some of these principles were applied by senior site managers and OHS representatives of five Victorian construction companies during OHS consultation at five different constructions sites, and whether this consultation could be considered to be meaningful and effective. The companies who participated in this project were each allocated a level of organisational maturity, dependent upon how they managed various aspects of their business operations in terms of OHS. Senior managers and OHS representatives were chosen as participants in the research because they are generally acknowledged as the critical vectors in the sharing and transferring of knowledge and skill at the workplace. The data from this research suggest that regardless of the level of organisational maturity each organisation was deemed to have reached, and no matter how the individual participants applied the particular moral and ethical principles used during this research, the OHS consultation that took place on the different construction sites was limited to, and focused primarily on, everyday operational and execution aspects of the job, rather than more strategic and longer term OHS issues. The practical implications of this research are that if OHS consultation between senior managers and OHS representatives can be conducted in such a way as to openly and unambiguously recognise and apply particular moral and ethical principles, and if consultation is allowed to focus on more strategic and longer term OHS and organisational aspects of a construction project, this may yield more benefits, in terms of OHS outcomes, for all industry participants.

Forensic identification and detection of hidden and obfuscated malware

  • Authors: Alazab, Mamoun
  • Date: 2012
  • Type: Text , Thesis , PhD
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  • Description: The revolution in online criminal activities and malicious software (malware) has posed a serious challenge in malware forensics. Malicious attacks have become more organized and purposefully directed. With cybercrimes escalating to great heights in quantity as well as in sophistication and stealth, the main challenge is to detect hidden and obfuscated malware. Malware authors use a variety of obfuscation methods and specialized stealth techniques of information hiding to embed malicious code, to infect systems and to thwart any attempt to detect them, specifically with the use of commercially available anti-malware engines. This has led to the situation of zero-day attacks, where malware inflict systems even with existing security measures. The aim of this thesis is to address this situation by proposing a variety of novel digital forensic and data mining techniques to automatically detect hidden and obfuscated malware. Anti-malware engines use signature matching to detect malware where signatures are generated by human experts by disassembling the file and selecting pieces of unique code. Such signature based detection works effectively with known malware but performs poorly with hidden or unknown malware. Code obfuscation techniques, such as packers, polymorphism and metamorphism, are able to fool current detection techniques by modifying the parent code to produce offspring copies resulting in malware that has the same functionality, but with a different structure. These evasion techniques exploit the drawbacks of traditional malware detection methods, which take current malware structure and create a signature for detecting this malware in the future. However, obfuscation techniques aim to reduce vulnerability to any kind of static analysis to the determent of any reverse engineering process. Furthermore, malware can be hidden in file system slack space, inherent in NTFS file system based partitions, resulting in malware detection that even more difficult.
  • Description: Doctor of Philosophy

Hermeneutic Constructivism : An Ontology for Qualitative Research

  • Authors: Peck, Blake
  • Date: 2012
  • Type: Text , Thesis , PhD
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  • Description: This thesis begins with contemporary qualitative research, where the extent of what is understood about human experience is reduced to the representations constructed by researchers. In this situation, where the qualitative researcher has a monopoly on the representation produced, there is no scope for a consideration of the expressive nature of language – in particular, the way that language discloses the world differently for each individual person. Thus, the aim of this thesis is to develop a theoretical approach for understanding the personal realities of the people involved in qualitative research that reinstates the centrality of the dialogic in understanding.
  • Description: Doctor of Philosophy

Large dataset complexity reduction for classification: An optimization perspective

  • Authors: Yatsko, Andrew
  • Date: 2012
  • Type: Text , Thesis , PhD
  • Full Text:
  • Description: Doctor of Philosophy
  • Description: Computational complexity in data mining is attributed to algorithms but lies hugely with the data. Different algorithms may exist to solve the same problem, but the simplest is not always the best. At the same time, data of astronomical proportions is rather common, boosted by automation, and the fuller the data, the better resolution of the concept it projects. Paradoxically, it is the computing power that is lacking. Perhaps a fast algorithm can be run on the data, but not the optimal. Even then any modeling is much constrained, involving serial application of many algorithms. The only other way to relieve the computational load is via making the data lighter. Any representative subset has to preserve the data essence suiting, ideally, any algorithm. The reduction should minimize the error of approximation, while trading precision for performance. Data mining is a wide field. We concentrate on classification. In the literature review we present a variety of methods, emphasizing the effort of past decade. Two major objects of reduction are instances and attributes. The data can be also recast into a more economical format. We address sampling, noise reduction, class domain binarization, feature ranking, feature subset selection, feature extraction, and also discretization of continuous features. Achievements are tremendous, but so are possibilities. We improve an existing technique of data cleansing and suggest a way of data condensing as the extension. We also touch on noise reduction. Instance similarity, excepting the class mix, prompts a technique of feature selection. Additionally, we consider multivariate discretization, enabling a compact data representation without the size change. We compare proposed methods with alternative techniques which we introduce new, implement or use available.

Learning Bayesian networks based on optimization approaches

  • Authors: Taheri, Sona
  • Date: 2012
  • Type: Text , Thesis , PhD
  • Full Text:
  • Description: Learning accurate classifiers from preclassified data is a very active research topic in machine learning and artifcial intelligence. There are numerous classifier paradigms, among which Bayesian Networks are very effective and well known in domains with uncertainty. Bayesian Networks are widely used representation frameworks for reasoning with probabilistic information. These models use graphs to capture dependence and independence relationships between feature variables, allowing a concise representation of the knowledge as well as efficient graph based query processing algorithms. This representation is defined by two components: structure learning and parameter learning. The structure of this model represents a directed acyclic graph. The nodes in the graph correspond to the feature variables in the domain, and the arcs (edges) show the causal relationships between feature variables. A directed edge relates the variables so that the variable corresponding to the terminal node (child) will be conditioned on the variable corresponding to the initial node (parent). The parameter learning represents probabilities and conditional probabilities based on prior information or past experience. The set of probabilities are represented in the conditional probability table. Once the network structure is constructed, the probabilistic inferences are readily calculated, and can be performed to predict the outcome of some variables based on the observations of others. However, the problem of structure learning is a complex problem since the number of candidate structures grows exponentially when the number of feature variables increases. This thesis is devoted to the development of learning structures and parameters in Bayesian Networks. Different models based on optimization techniques are introduced to construct an optimal structure of a Bayesian Network. These models also consider the improvement of the Naive Bayes' structure by developing new algorithms to alleviate the independence assumptions. We present various models to learn parameters of Bayesian Networks; in particular we propose optimization models for the Naive Bayes and the Tree Augmented Naive Bayes by considering different objective functions. To solve corresponding optimization problems in Bayesian Networks, we develop new optimization algorithms. Local optimization methods are introduced based on the combination of the gradient and Newton methods. It is proved that the proposed methods are globally convergent and have superlinear convergence rates. As a global search we use the global optimization method, AGOP, implemented in the open software library GANSO. We apply the proposed local methods in the combination with AGOP. Therefore, the main contributions of this thesis include (a) new algorithms for learning an optimal structure of a Bayesian Network; (b) new models for learning the parameters of Bayesian Networks with the given structures; and finally (c) new optimization algorithms for optimizing the proposed models in (a) and (b). To validate the proposed methods, we conduct experiments across a number of real world problems. Print version is available at: http://library.federation.edu.au/record=b1804607~S4
  • Description: Doctor of Philosophy