Structured representation learning from complex data

This thesis advances several theoretical and practical aspects of the recently introduced restricted Boltzmann machine - a powerful probabilistic and generative framework for modelling data and learning representations. The contributions of this study represent a systematic and common theme in learning structured representations from complex data.

Factors associated with breast and cervical cancer screening behaviours

To investigate the factors associated with the use of screening mammography for breast cancer and cervical smear tests for cervical cancer, a theoretical framework was used comprising elements from the Health Belief Model, the Theory of Reasoned Action, and illness representations from the self-regulatory model. Items reflecting older women’s illness representations about cancer and cancer screening were derived from an earlier qualitative study. Using a highly structured interview schedule, telephone interviews were conducted with 1,200 women aged 50-70 years. There were considerable similarities between the factors associated with both mammography and cervical smear test behaviours. The factors associated with screening mammography behaviour were: perceived barriers, perceived benefits, social influence, the illness representations, and marital status. The factors associated with cervical smear test behaviour were: perceived barriers, perceived benefits, emotions as a cause of cancer, feeling frightened of cancer, the illness representations, having a usual general practitioner, and being younger.

Relationships between identity and self-representations during adolescence

By drawing from literature on identity development as well as on self-discrepancy, the present study aimed to investigate variations in the magnitude of self-belief discrepancies among adolescents with different levels of identity development. The respondents consisted of 336 male and female adolescents, from 5 private secondary schools, ranging in age from 14 to 18 years (M = 15.98, SD = 0.89). Four levels of identity status (Achieved, Moratorium, Foreclosed, and Diffused identity status) were used as the method of identity classification in this study. Four types of self-discrepancies (Actual/Ideal (own), Actual/Ideal (other), Actual/Ought (own), and Actual/Ought (other) self-discrepancy) were also obtained. Multivariate analyses of variance showed that respondents with different identity statuses significantly varied on the magnitude of self-discrepancy experienced. The Foreclosed and Achieved statuses were found to have lower levels of self-belief discrepancy than the Moratorium and Diffused statuses. However, most of the significant differences among the statuses were for the Actual/Ideal (own) and Actual/Ideal (other) self-discrepancies. These results indicate that identity development is related to the magnitude of self-belief discrepancy. However, further research with more developed instruments is needed to explore this relationship more fully.

Modelling solute transport in structured soils: performance evaluation of the ADR and TRM models

The movement of chemicals through the soil to the groundwater or discharged to surface waters represents a degradation of these resources. In many cases, serious human and stock health implications are associated with this form of pollution. The chemicals of interest include nutrients, pesticides, salts, and industrial wastes. Recent studies have shown that current models and methods do not adequately describe the leaching of nutrients through soil, often underestimating the risk of groundwater contamination by surface-applied chemicals and overestimating the concentration of resident solutes. This inaccuracy results primarily from ignoring soil structure and nonequilibrium between soil constituents, water, and solutes. A multiple sample percolation system (MSPS), consisting of 25 individual collection wells, was constructed to study the effects of localized soil heterogeneities on the transport of nutrients (NO−3, Cl−, PO3−4) in the vadose zone of an agricultural soil predominantly dominated by clay. Very significant variations in drainage patterns across a small spatial scale were observed (one-way ANOVA, p < 0.001 indicating considerable heterogeneity in water flow patterns and nutrient leaching. Using data collected from the multiple sample percolation experiments, this paper compares the performance of two mathematical models for predicting solute transport, the advective-dispersion model with a reaction term (ADR), and a two-region preferential flow model (TRM) suitable for modelling nonequilibrium transport. These results have implications for modelling solute transport and predicting nutrient loading on a larger scale.

Elections and representations in local government: A Victorian case study

This article examines the application of different views of representation in the electoral systems at local government level: interest, corporate and mirror representation. The electoral framework underpins the process of representation, influencing both who are eligible to become voters and how their votes are collected and counted. The paper examines the  interrelationship between representation and the electoral framework in local government in Victoria. We use a historical analysis, and identify a long period of interest representation; a short, relatively recent period of corporate representation; and an attempt to introduce some elements of mirror representation. We conclude by arguing that local electoral reform needs to take into account the multiple meanings of representation.

Does successful treatment of constipation or faecal impaction resolve lower urinary tract symptoms? A structured review of the literature

Consensus guidelines advocate the treatment of constipation and faecal impaction in order to improve symptoms of urinary frequency, urgency and urinary incontinence and to promote bladder emptying in the absence of urinary tract obstruction. This structured review of the literature was undertaken to search for and appraise evidence to support or negate the hypothesis of this relationship. The search strategy was comprehensive and identified six relevant studies. Two of these had been conducted on an adult population and four studies involved children with constipation. These studies were appraised for methodological quality. It was found that sample sizes were small and evidence was inconsistent. Variable methods of reporting meant that data were not able to be pooled for meta-analysis.
Based on the limited and conflicting evidence, it is recommended that further research be undertaken to identify any correlation between bowel and bladder function.

Teaching HRD personnel : experiences of computer-mediated communication in differently structured environments

This paper will provide an overview of the CMC structure in two different units of study in the Masters of Professional Education and Training at Deakin University. Each of these structures makes a set of demands on participants, and provides differing collaborative learning opportunities. The paper examines the experiences we have had in each of these structures, focusing on student participation, style of contribution to CMC, and the relationship between socialisation processes and knowledge construction.

Altered images : the relations between design representations and design practice

As information systems move out of the office into the wider world and are merged with mobile appliances, buildings and even clothing, the representations traditionally used in any one discipline may not be adequate for understanding these new domains. Design representations are ‘ways of seeing and not seeing’. Despite the central role representations play in design, the information systems design community has little understanding of the relation, ideal or actual, between design practice and design representation. This paper reports on an extensive design case study that aims at increasing understanding of the nature and affordances of representations in the design process and argues for the need for information systems as a discipline to open up discussion of the design representations that may be required to effectively design systems that mix traditional IS with disciplines such as industrial design, architecture and fashion design.

Developing student agency through VET in schools: the role of structured work placements

Using a sample of 446 secondary students who had participated in a vocational education and training in school (VETiS) program, this study compares the experiences and perceptions of students who had undertaken a work placement with those who had not. The study shows that students who had participated in work placement enjoyed the VETiS experience more than those who had not, and that the work placement had assisted them in their decision whether to stay at school or not. A factor analysis of results showed a factor associated with self-confidence about employability, and a factor associated with assistance in achieving specific post-school employment. Students who had completed a work placement were significantly higher on both these factors than students who had not.

These results are consistent with other research in the field, and it is argued that the work placement experience plays a considerable part in developing student agency in the decisions and the journey that they make in their transition from school to work.

High stakes principalship-sleepless nights, heart attacks and sudden death accountabilities: reading media representations of the United States principal shortage

The possible shortage of applicants for principal positions is news in both Australia and abroad. We subject a corpus of predominantly United states (US) news articles to deconstructive narrative analysis and find that the dominant media representation of principals' work is one of long hours Iow salary high stress and sudden death from high stakes accountabilities. However, reported US policy interventions focus predominantly on professional development for aspirants. We note that this will be insufficient to reverse the lack of applications and suggest that the dominant media picture of completely unattractive principals work, meant to leverage a policy solution, will perhaps paradoxically perpetuate the problem. The dominant media picture is also curiously at odds with research that reports high job satisfaction among principals. We suggest that there is a binary of victim and saviour principal in both media and policy which prevents some strategic re-thinking about how the principalship might be different.

Representation and learning about evaporation

While there has been considerable research on children's understanding of evaporation, the representational issues entailed in this understanding have not been investigated in depth. This study explored students' engagement with evaporation phenomena through various representational modes. Primary school classroom sequences and structured interviews shortly after, and a year later, indicated significant advances in learning flowing from negotiation of meaning around particle representations. A case study of one child's learning is used to demonstrate how a molecular distribution representation can offer the possibility of significant advances in children's thinking about evaporation. The findings suggest that teacher-mediated negotiation of representational issues can support enriched student learning