An improved trust model in agent-mediated E-commerce

Trust is a fundamental issue in multiagent systems, especially in agent-mediated e-commence. The trust model plays an important role in determining who and how to interact in open and dynamic environments. To this end, many trust models have been developed. Based on the confidence–reputation model proposed by other researchers, an improved trust model is discussed. The original model was enhanced in two aspects: (1) when evaluating the trustworthiness of target agents, the reliability of the witness itself is taken into account and further aggregated by Dempster-Shafer evidence theory and (2) the ontological property of trust is considered, which implies that trust can be calculated more precisely. A case study is provided to show the effectiveness of the improved model.

The addition of depression to the Framingham Risk Equation model for predicting coronary heart disease risk in women

BACKGROUND: Depression is widely considered to be an independent and robust predictor of Coronary Heart Disease (CHD), however is seldom considered in the context of formal risk assessment. We assessed whether the addition of depression to the Framingham Risk Equation (FRE) improved accuracy for predicting 10-year CHD in a sample of women.

DESIGN: A prospective, longitudinal design comprising an age-stratified, population-based sample of Australian women collected between 1993 and 2011 (n=862).

METHODS: Clinical depressive disorder was assessed using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (SCID-I/NP), using retrospective age-of-onset data. A composite measure of CHD included non-fatal myocardial infarction, unstable angina coronary intervention or cardiac death. Cox proportional-hazards regression models were conducted and overall accuracy assessed using area under receiver operating characteristic (ROC) curve analysis.

RESULTS: ROC curve analyses revealed that the addition of baseline depression status to the FRE model improved its overall accuracy (AUC:0.77, Specificity:0.70, Sensitivity:0.75) when compared to the original FRE model (AUC:0.75, Specificity:0.73, Sensitivity:0.67). However, when calibrated against the original model, the predicted number of events generated by the augmented version marginally over-estimated the true number observed.

CONCLUSIONS: The addition of a depression variable to the FRE equation improves the overall accuracy of the model for predicting 10-year CHD events in women, however may over-estimate the number of events that actually occur. This model now requires validation in larger samples as it could form a new CHD risk equation for women.

Cost and feasibility of a barrier to halt the spread of invasive cane toads in arid Australia: incorporating expert knowledge into model-based decision-making

1. Active engagement with practitioners is a crucial component of model-based decision-making in conservation management; it can assist with data acquisition, improve models and help narrow the 'knowing-doing' gap.
2. We worked with practitioners of one of the worst invasive species in Australia, the cane toad Rhinella marina, to revise a model that estimates the effectiveness of landscape barriers to contain spread. The original model predicted that the invasion could be contained by managing artificial watering points on pastoral properties, but was initially met with scepticism by practitioners, in part due to a lack of engagement during model development.
3. We held a workshop with practitioners and experts in cane toad biology. Using structured decision-making, we elicited concerns about the original model, revised its structure, updated relevant input data, added an economic component and found the most cost-effective location for a barrier across a range of fixed budgets and management scenarios. We then conducted scenario analyses to test the sensitivity of management decisions to model revisions.
4. We found that toad spread could be contained for all of the scenarios tested. Our modelling suggests a barrier could cost $4·5 M (2015 AUD) over 50 years for the most likely landscape scenario. The incorporation of practitioner knowledge into the model was crucial. As well as improving engagement, when we incorporated practitioner concerns (particularly regarding the effects of irrigation and dwellings on toad spread), we found a different location for the optimal barrier compared to a previously published study (Tingley et al. 2013).
5. Synthesis and applications. Through engagement with practitioners, we turned an academic modelling exercise into a decision-support tool that integrated local information, and considered more realistic scenarios and constraints. Active engagement with practitioners led to productive revisions of a model that estimates the effectiveness of a landscape barrier to contain spread of the invasive cane toad R. marina. Benefits also include greater confidence in model predictions, improving our assessment of the cost and feasibility of containing the spread of toads.

Exploring multidimensional person-environment fit

The current study examines the validity of a multidimensional Person-Environment (PE) fit model proposed by Jansen and Kristof-Brown (2006). The overall aim of the paper is to test the model’s factor structure and influences upon outcome measures. A panel of organisational employees from a wide range of companies and locations were asked to complete a survey (n = 1875) measuring five discrete multidimensional facets of PE fit (Person-Organisation, Person-People, Person-Job, Person-Group and Person-Vocation) and three outcomes; organisational commitment, intention to leave and job satisfaction. The first sequence of analysis tested the proposed model using Confirmatory Factor Analysis (CFA) statistical approaches. Model comparisons showed that Jansen and Kristof-Brown’s original model in which the five facets of fit coalesce into a multidimensional variable was a poor fit with the data, but that a model in which the five facets of fit operate independently was a good fitting one. The second sequence of analysis found that the model without the multidimensional variable strongly predicted the outcomes of commitment, job satisfaction and intention to leave. This paper discusses the implication of this research in relation to the PE fit literature.

Testing a multidimensional theory of person-environment fit

The current study examines the validity of a multidimensional Person-Environment (PE) fit model proposed by Jansen and Kristof-Brown (2006). The overall aim of the paper is to test the model's factor structure and influences upon outcome measures. A panel of organizational employees from a wide range of companies and locations were asked to complete a survey (n = 1,875) measuring five discrete dimensions of perceptual PE fit (Person-Organization, Person-People, Person-Job, Person-Group, and Person-Vocation) and three outcomes (organizational commitment, intention to leave, and job satisfaction). The first sequence of analysis tested the proposed model using Confirmatory Factor Analysis (CFA) statistical approaches. Model comparisons showed that Jansen and Kristof-Brown's (2006) original model in which the five dimensions of fit coalesce into a multidimensional construct was a poor fit with the data, but that a model in which the five dimensions of fit operate independently fit the data well. The second sequence of analysis found that the model without the multidimensional construct strongly predicted the outcomes of commitment, job satisfaction, and intention to leave. This paper discusses the implication of this research in relation to the PE fit literature.

Development of play profiles : influence of disability on children's play

Occupational therapists value play as a significant occupation in a child’s life and use play both as a means and as an end in itself to support development. This thesis explores the nature of play in children with developmental disabilities, seeking to determine whether there are consistent patterns of play specific to different disability categories. An extensive literature review of play and disability was completed, and Cooper’s (2000) model of play is used to organize the literature findings. This study investigated differences in play behaviour in 50 children diagnosed with Autistic Spectrum Disorder, Down syndrome, Developmental Delay and Physical impairments, aged 4 to 6 years 6 months who attended educational facilities in a regional centre in South East Queensland. Quantitative and qualitative play behaviour was assessed using two measures, Revised Knox Preschool Play Scale (Knox, 2008) and the Child Initiated Pretend Play Assessment (Stagnitti, 2007) with the Australian Developmental Screening Test (Burdon, 1993) used to determine developmental age to eliminate this as a potential confounding variable when statistically analyzing the results.
Cognitive, language and fine motor abilities were found to have a statistically significant impact on play ability rather than the different disability groupings. Children with Down syndrome had significantly more imitative play actions than any other disability grouping. Cooper’s (2000) model was found to be a useful tool to analyze differing play characteristics according to different disability groupings. Modifications to Cooper’s original model of play to more accurately depict play characteristics are proposed.

A university-based clinical exercise facility that serves as a clinical, teaching and research space

Deakin University opened its Clinical Exercise Learning Centre (CELC) in May 2011, initially staffed by four (now seven) Accredited Exercise Physiologists (AEP), and funded by the university. The main objectives of CELC are to provide (i) excellent clinical practicum learning opportunities for postgraduate students enrolled in the Master of Clinical Exercise Physiology that prepare students for subsequent external placements; (ii) learning opportunities that are vertically integrated with the preparatory components of the Masters, including pathophysiology units and pre-clinical units; (iii) learning opportunities that are also integrated with the external clinical practicum program that is embedded in the Masters; (iv) a clinical service to the community and strong referral networks with local GPs; (v) a research centre that is focussed on evaluating the efficacy of Accredited Exercise Physiology (AEP) services for a range of clinical situations, with a view to contributing to a future national evidence-based practice network supported by ESSA. Deakin University funds the CELC facility, equipment, consumables, limited car parking, practice management software and server and, most importantly, the staff. Therefore CELC runs at a loss even against fees charged and this was built into the original model. Staff include an AEP clinical practicum coordinator, two casual AEPs and several academic AEPs; the latter practise as a small part of their approved workloads. The practice model is for all AEPs to provide clinical services with referred clients who are billed as if CELC is a private practice, whilst concurrently teaching and mentoring students; the latter are expected to be active learners in CELC and have exposure to a wide range of pathologies and clinical situations. Billable hours are always provided by AEPs, not students, but students can assist. CELC provides clinical services 1:1:1 (client: AEP: student), 1:1:5 and 8:1:5. CELC was awarded national runner-up in the ESSA Exercise Physiology clinic of the year in 2011 and has grown its caseload to > 200 referrers in 2013. CELC recently designed a generic research platform and has begun to roll out research projects that are designed to translate 'traditional' research-based evidence of exercise benefits for chronic disease in order to evaluate AEP efficacy of practice in the Australian context. CELC provides a model for other universities, provided those universities see it for its learning value, and not to generate revenue or profit.

Assessing the strain experienced by managers and professional Australian footballers using an augmented job strain model

Generic models of job stress, such as the Job Strain Model (JSM), have recently been criticised for focusing on a small number of general work characteristics while ignoring those that are occupation-specific (Sparks & Cooper, 1999). However this criticism is based on limited research that has not examined the relative influence of all three dimensions of the JSM - job demand, job control and social support - and job-specific stressors. The JSM is the most commonly used model underpinning large-scale occupational stress research (Fox, Dwyer, & Ganster, 1993) and is regarded as the most influential model in the research on the psycho-social work environment, stress and disease in recent times (Kristensen, 1995). This thesis addresses the lack of information on the relative influence of the JSM and job-specific stressors by assessing the capacity of an augmented JSM to predict the strain experienced by managers and professional Australian footballers. The augmented JSM consisted of job-specific stressors in addition to the generic components of the model. Managers and professional Australian footballers represent two very different occupational groups. While the day-today roles of a manager include planning, organising, monitoring and controlling (Carroll & Gillen, 1987), the working life of a professional Australian footballer revolves around preparing for and playing football (Shanahan, 1998). It was expected that the large differences in the work undertaken by managers and professional Australian footballers would maximise the opportunities for identifying job-specific stressors and measuring the extent that these vary from one group to the next. The large disparity between managers and professional footballers was also used to assess the cross-occupational versatility of the JSM when it had been augmented by job-specific stressors. This thesis consisted of three major studies. Study One involved a survey of Australian managers, while studies Two and Three focused on professional Australian footballers. The latter group was under-represented in the literature, and as a result of the lack of information on the stressors commonly experienced by this group, an in-depth qualitative study was undertaken in Study Two. The results from Study Two then informed the survey of professional footballers that was conducted in Study Three. Contrary to previous research examining the relative influence of generic and job-specific stressors, the results only provided moderate support for augmenting the JSM with job-specific stressors. Instead of supporting the versatility of the augmented JSM, the overall findings reinforced the broad relevance of the original JSM. Of the four health outcomes measured in Studies One and Three, there was only one - the psychological health of professional Australian footballers - where the proportion of total variance explained by job-specific stressors exceeded 13%. Despite the generally strong performance of the JSM across the two occupational groups, the importance of demand, control and support diminished when examining the less conventional occupation of professional football. The generic model was too narrow to capture the highly specific work characteristics that are important for this occupational group and, as a result, the job-specific stressors explained significantly more of the strain over and above that already provided by the generic model. These findings indicate that when investigating the stressors experienced by conventional occupational groups such as managers, the large amount resources required to identify job-specific stressors are unlikely to be cost-effective. In contrast, the influence of the more situation specific stressors is significantly greater in unconventional occupations and thus the benefits of identifying these non-generic stressors are more likely to outweigh the costs. Studies One and Three identified strong connections between job-specific stressors and important characteristics of the occupation being studied. These connections were consistent with previous research and suggest that before attempting to identify job-specific stressors, researchers need to first become familiar with the nature and context of the occupation. The final issue addressed in this thesis was the role of work and non-work support. The findings indicate that the support provided by supervisors and colleagues was a significant predictor of wellbeing for both managers and professional footballers. In contrast, the level of explained strain accounted for by non-work support was not significant. These results indicate that when developing strategies to protect and enhance employee well-being, particular attention should be given to monitoring and, where necessary, boosting the effectiveness of work-based support. The findings from this thesis have been fed back to the management and sporting communities via conference presentations and peer-reviewed journals (refer pp 220-221). All three studies have been presented at national and international conferences and, overall, were well received by participants. Similarly, the methods, results and major findings arising from Studies One and Two have been critiqued by anonymous reviewers from two international journals. These papers have been accepted for publication in 2001 and 2002 and feedback from the reviewers indicates that the findings represent a significant and unique contribution to the literature. The results of Study Three are currently under review by a sports psychology journal.

Towards the development of a construction supply chain transaction cost economic model for strategic infrastructure procurement evaluation

Australia has adopted public-private partnership (PPP) as a major strategy for procuring infrastructure for decades. However, even though considered to be a mature and sophisticated market, several major
failures have occurred resulting in increasing financial burdens on taxpayers. Failures have typically been traced back to economic evaluation and, in particular, value-for-money across the supply chain
in the original proposal. However, the literature review identified that there was no economic model that evaluated holistically the transaction costs of PPPs across the supply chain. In this paper, theories of transaction cost economics and construction supply chain economics are critiqued and analysed in order to develop a strategic infrastructure procurement evaluation model. The model will offer decision makers with an insight into project life cycle economic outcomes needed to successfully deliver PPPs.

Rehabilitation, etiology, and self-regulation : the comprehensive good lives model of treatment for sexual offenders

In this paper, we draw upon two sets of theoretical resources to develop a comprehensive theory of sexual offender rehabilitation named the Good Lives Model-Comprehensive (GLM-C). The original Good Lives Model (GLM-O) forms the overarching values and principles guiding clinical practice in the GLM-C. In addition, the latest sexual offender theory (i.e., the Integrated Theory of Sexual Offending; ITSO) provides a clear etiological grounding for these principles. The result is a more substantial and improved rehabilitation model that is able to conceptually link latest etiological theory with clinical practice. Analysis of the GLM-C reveals that it also has the theoretical resources to secure currently used self-regulatory treatment practice within a meaningful structure.

A mutation-based evolving neural network model and its application to condition monitoring

Data analysis using intelligent systems is a key solution to many industrial problems. In this paper, a mutation-based evolving artificial neural network, which is based on an integration of the Fuzzy ARTMAP (FAM) neural network and evolutionary programming (EP), is proposed. The proposed FAMEP model is applied to detect and classify possible faults from a number of sensory signals of a circulating water system in a power generation plant. The efficiency of FAM-EP is assessed and compared with that of the original FAM network in terms of classification accuracy as well as network complexity. In addition, the bootstrap method is used to quantify the performance statistically. The results positively demonstrate the usefulness of FAM-EP in tackling data classification problems.

A hierarchical PCA-based anomaly detection model

A hierarchical intrusion detection model is proposed to detect both anomaly and misuse attacks. In order to further speed up the training and testing, PCA-based feature extraction algorithm is used to reduce the dimensionality of the data. A PCA-based algorithm is used to filter normal data out in the upper level. The experiment results show that PCA can reduce noise in the original data set and the PCA-based algorithm can reach the desirable performance.

A genetic fuzzy system to model pedestrian walking path in a built environment

A study on the pedestrian's steering behaviour through a built environment in normal circumstances is presented in this paper. The study focuses on the relationship between the environment and the pedestrian's walking trajectory. Owing to the ambiguity and vagueness of the relationship between the pedestrians and the surrounding environment, a genetic fuzzy system is proposed for modelling and simulation of the pedestrian's walking trajectory confronting the environmental stimuli. We apply the genetic algorithm to search for the optimum membership function parameters of the fuzzy model. The proposed system receives the pedestrian's perceived stimuli from the environment as the inputs, and provides the angular change of direction in each step as the output. The environmental stimuli are quantified using the Helbing social force model. Attractive and repulsive forces within the environment represent various environmental stimuli that influence the pedestrian's walking trajectory at each point of the space. To evaluate the effectiveness of the proposed model, three experiments are conducted. The first experimental results are validated against real walking trajectories of participants within a corridor. The second and third experimental results are validated against simulated walking trajectories collected from the AnyLogic® software. Analysis and statistical measurement of the results indicate that the genetic fuzzy system with optimised membership functions produces more accurate and stable prediction of heterogeneous pedestrians' walking trajectories than those from the original fuzzy model. © 2014 Elsevier B.V. All rights reserved.

Deferentially private tagging recommendation based on topic model

Tagging recommender system allows Internet users to annotate resources with personalized tags and provides users the freedom to obtain recommendations. However, It is usually confronted with serious privacy concerns, because adversaries may re-identify a user and her/his sensitive tags with only a little background information. This paper proposes a privacy preserving tagging release algorithm, PriTop, which is designed to protect users under the notion of differential privacy. The proposed PriTop algorithm includes three privacy preserving operations: Private Topic Model Generation structures the uncontrolled tags, Private Weight Perturbation adds Laplace noise into the weights to hide the numbers of tags; while Private Tag Selection finally finds the most suitable replacement tags for the original tags. We present extensive experimental results on four real world datasets and results suggest the proposed PriTop algorithm can successfully retain the utility of the datasets while preserving privacy. © 2014 Springer International Publishing.

A multi-objective ant colony optimization algorithm based on the physarum-inspired mathematical model

Multi-objective traveling salesman problem (MOTSP) is an important field in operations research, which has wide applications in the real world. Multi-objective ant colony optimization (MOACO) as one of the most effective algorithms has gained popularity for solving a MOTSP. However, there exists the problem of premature convergence in most of MOACO algorithms. With this observation in mind, an improved multiobjective network ant colony optimization, denoted as PMMONACO, is proposed, which employs the unique feature of critical tubes reserved in the network evolution process of the Physarum-inspired mathematical model (PMM). By considering both pheromones deposited by ants and flowing in the Physarum network, PM-MONACO uses an optimized pheromone matrix updating strategy. Experimental results in benchmark networks show that PM-MONACO can achieve a better compromise solution than the original MOACO algorithm for solving MOTSPs.