A hybrid recommender systems based on weighted tags

Social tags in web 2.0 are becoming another important information source to describe the content of items as well as to profile users’ topic preferences. However, as arbitrary words given by users, tags contains a lot of noise such as tag synonym and semantic ambiguity a large number personal tags that only used by one user, which brings challenges to effectively use tags to make item recommendations. To solve these problems, this paper proposes to use a set of related tags along with their weights to represent semantic meaning of each tag for each user individually. A hybrid recommendation generation approaches that based on the weighted tags are proposed. We have conducted experiments using the real world dataset obtained from Amazon.com. The experimental results show that the proposed approaches outperform the other state of the art approaches.

Control and protection of a microgrid connected to utility through back-to-back converters

This paper discusses the control and protection of a microgrid that is connected to utility through back-to-back converters. The back-to-back converter connection facilitates bidirectional power flow between the utility and the microgrid. These converters can operate in two different modes–one in which a fixed amount of power is drawn from the utility and the other in which the microgrid power shortfall is supplied by the utility. In the case of a fault in the utility or microgrid side, the protection system should act not only to clear the fault but also to block the back-to-back converters such that its dc bus voltage does not fall during fault. Furthermore, a converter internal mechanism prevents it from supplying high current during a fault and this complicates the operation of a protection system. To overcome this, an admittance based relay scheme is proposed, which has an inverse time characteristic based on measured admittance of the line. The proposed protection and control schemes are able to ensure reliable operation of the microgrid.

Swell : a feature-length screenplay set in the world of Australian surfing, and an accompanying exegesis on three-act structure

Despite many arguments to the contrary, the three-act story structure, as propounded and refined by Hollywood continues to dominate the blockbuster and independent film markets. Recent successes in post-modern cinema could indicate new directions and opportunities for low-budget national cinemas.

Characteristics of utility cyclists in Queensland, Australia : an examination of the associations between individual, social and environmental factors and utility cycling

Background: Initiatives to promote utility cycling in countries like Australia and the US, which have low rates of utility cycling, may be more effective if they first target recreational cyclists. This study aimed to describe patterns of utility cycling and examine its correlates, among cyclists in Queensland, Australia. Methods: An online survey was administered to adult members of a state-based cycling community and advocacy group (n=1813). The survey asked about demographic characteristics and cycling behavior, motivators and constraints. Utility cycling patterns were described, and logistic regression modeling was used to examine associations between utility cycling and other variables. Results: Forty-seven percent of respondents reported utility cycling: most did so to commute (86%). Most journeys (83%) were >5 km. Being male, younger, employed full-time, or university-educated increased the likelihood of utility cycling (p<0.05). Perceiving cycling to be a cheap or a convenient form of transport were associated with utility cycling (p<0.05). Conclusions: The moderate rate of utility cycling among recreational cyclists highlights a potential to promote utility cycling among this group. To increase utility cycling, strategies should target female and older recreational cyclists and focus on making cycling a cheap and convenient mode of transport.

Illegal street racing and associated (hooning) behaviours

In an Australian context, the term hooning refers to risky driving behaviours such as illegal street racing and speed trials, as well as behaviours that involve unnecessary noise and smoke, which include burn outs, donuts, fish tails, drifting and other skids. Hooning receives considerable negative media attention in Australia, and since the 1990s all Australian jurisdictions have implemented vehicle impoundment programs to deal with the problem. However, there is limited objective evidence of the road safety risk associated with hooning behaviours. Attempts to estimate the risk associated with hooning are limited by official data collection and storage practices, and the willingness of drivers to admit to their illegal behaviour in the event of a crash. International evidence suggests that illegal street racing is associated with only a small proportion of fatal crashes; however, hooning in an Australian context encompasses a broader group of driving behaviours than illegal street racing alone, and it is possible that the road safety risks will differ with these behaviours. There is evidence from North American jurisdictions that vehicle impoundment programs are effective for managing drink driving offenders, and drivers who continue to drive while disqualified or suspended both during and post-impoundment. However, these programs used impoundment periods of 30 – 180 days (depending on the number of previous offences). In Queensland the penalty for a first hooning offence is 48 hours, while the vehicle can be impounded for up to 3 months for a second offence, or permanently for a third or subsequent offence within three years. Thus, it remains unclear whether similar effects will be seen for hooning offenders in Australia, as no evaluations of vehicle impoundment programs for hooning have been published. To address these research needs, this program of research consisted of three complementary studies designed to: (1) investigate the road safety implications of hooning behaviours in terms of the risks associated with the specific behaviours, and the drivers who engage in these behaviours; and (2) assess the effectiveness of current approaches to dealing with the problem; in order to (3) inform policy and practice in the area of hooning behaviour. Study 1 involved qualitative (N = 22) and quantitative (N = 290) research with drivers who admitted engaging in hooning behaviours on Queensland roads. Study 2 involved a systematic profile of a large sample of drivers (N = 834) detected and punished for a hooning offence in Queensland, and a comparison of their driving and crash histories with a randomly sampled group of Queensland drivers with the same gender and age distribution. Study 3 examined the post-impoundment driving behaviour of hooning offenders (N = 610) to examine the effects of vehicle impoundment on driving behaviour. The theoretical framework used to guide the research incorporated expanded deterrence theory, social learning theory, and driver thrill-seeking perspectives. This framework was used to explore factors contributing to hooning behaviours, and interpret the results of the aspects of the research designed to explore the effectiveness of vehicle impoundment as a countermeasure for hooning. Variables from each of the perspectives were related to hooning measures, highlighting the complexity of the behaviour. This research found that the road safety risk of hooning behaviours appears low, as only a small proportion of the hooning offences in Study 2 resulted in a crash. However, Study 1 found that hooning-related crashes are less likely to be reported than general crashes, particularly when they do not involve an injury, and that higher frequencies of hooning behaviours are associated with hooning-related crash involvement. Further, approximately one fifth of drivers in Study 1 reported being involved in a hooning-related crash in the previous three years, which is comparable to general crash involvement among the general population of drivers in Queensland. Given that hooning-related crashes represented only a sub-set of crash involvement for this sample, this suggests that there are risks associated with hooning behaviour that are not apparent in official data sources. Further, the main evidence of risk associated with the behaviour appears to relate to the hooning driver, as Study 2 found that these drivers are likely to engage in other risky driving behaviours (particularly speeding and driving vehicles with defects or illegal modifications), and have significantly more traffic infringements, licence sanctions and crashes than drivers of a similar (i.e., young) age. Self-report data from the Study 1 samples indicated that Queensland’s vehicle impoundment and forfeiture laws are perceived as severe, and that many drivers have reduced their hooning behaviour to avoid detection. However, it appears that it is more common for drivers to have simply changed the location of their hooning behaviour to avoid detection. When the post-impoundment driving behaviour of the sample of hooning offenders was compared to their pre-impoundment behaviour to examine the effectiveness of vehicle impoundment in Study 3, it was found that there was a small but significant reduction in hooning offences, and also for other traffic infringements generally. As Study 3 was observational, it was not possible to control for extraneous variables, and is, therefore, possible that some of this reduction was due to other factors, such as a reduction in driving exposure, the effects of changes to Queensland’s Graduated Driver Licensing scheme that were implemented during the study period and affected many drivers in the offender sample due to their age, or the extension of vehicle impoundment to other types of offences in Queensland during the post-impoundment period. However, there was a protective effect observed, in that hooning offenders did not show the increase in traffic infringements in the post period that occurred within the comparison sample. This suggests that there may be some effect of vehicle impoundment on the driving behaviour of hooning offenders, and that this effect is not limited to their hooning driving behaviour. To be more confident in these results, it is necessary to measure driving exposure during the post periods to control for issues such as offenders being denied access to vehicles. While it was not the primary aim of this program of research to compare the utility of different theoretical perspectives, the findings of the research have a number of theoretical implications. For example, it was found that only some of the deterrence variables were related to hooning behaviours, and sometimes in the opposite direction to predictions. Further, social learning theory variables had stronger associations with hooning. These results suggest that a purely legal approach to understanding hooning behaviours, and designing and implementing countermeasures designed to reduce these behaviours, are unlikely to be successful. This research also had implications for policy and practice, and a number of recommendations were made throughout the thesis to improve the quality of relevant data collection practices. Some of these changes have already occurred since the expansion of the application of vehicle impoundment programs to other offences in Queensland. It was also recommended that the operational and resource costs of these laws should be compared to the road safety benefits in ongoing evaluations of effectiveness to ensure that finite traffic policing resources are allocated in a way that produces maximum road safety benefits. However, as the evidence of risk associated with the hooning driver is more compelling than that associated with hooning behaviour, it was argued that the hooning driver may represent the better target for intervention. Suggestions for future research include ongoing evaluations of the effectiveness of vehicle impoundment programs for hooning and other high-risk driving behaviours, and the exploration of additional potential targets for intervention to reduce hooning behaviour. As the body of knowledge regarding the factors contributing to hooning increases, along with the identification of potential barriers to the effectiveness of current countermeasures, recommendations for changes in policy and practice for hooning behaviours can be made.

IS-impact utility and intuitiveness : a rigorous approach to relevance

The study proposes to test the ‘IS-Impact’ index as Analytic Theory (AT). To (a) methodically evaluate the ‘relevance’ qualities of IS-Impact; namely, Utility & Intuitiveness. In so doing, to (b) document an exemplar of ‘a rigorous approach to relevance’, while (c) treating the overarching study as a higher-order case study having AT as the unit-of-analysis, and assessing adequacy of the 6 AT qualities, both for IS-Impact and for similar taxonomies. Also to (d) look beyond IS-Impact to other forms of Design Science, considering the generality of the AT qualities; and (e) further validating IS-Impact in new system organisation contexts taking account of contemporary understandings of construct theorisation, operationalization and validation.

Parent decisions regarding paid work and care of the child

Australia has witnessed a continual increase in maternal employment over the past two decades, which has placed focus on child care- its effects on the child and on early childhood education and care policy and provision. The engagement of women in the paid workforce contributes to national economic development, and is recognised in government policy incentives such as cash subsidies and tax relief for child care fees. These incentives are targeted towards mothers, to encourage them to engage in paid work. Making a contribution to the family’s economy and to a mother’s economic self sufficiency are two key drivers for women’s engagement in satisfying paid work. Many women also seek to maintain a personal investment in the development of their career, simultaneously ensuring that the child is experiencing suitable care. Policies that support women’s choices for satisfying workforce engagement and care arrangements are prudent for ensuring productivity of the economy as well as for enhancing the wellbeing of parents and children (OECD, 2007). Policies that provide family friendly employment arrangements, paid parental leave, and child care support, directly affect maternal employment decisions. Availability of family friendly employment policies is viewed as one way to not only promote gender equity in employment opportunities but also support the wellbeing of children and families (OECD, 2007). Yet there are not comprehensive and coherent policies on work and family in Australia. Australia is due to implement its first paid parental leave scheme in January, 2011. At the time of the data collection of this research, June 2007 to December 2008, Australia had no statutory provision for paid parental leave. To date, most research has focused on the consequences of paid work and care decisions made by women. Far less is known about the processes of decision-making and reasons underlying women’s choices. Investigation of what is most salient for women as they make decisions regarding engagement in paid work, and care for their child is important in order to inform policy and practices related to parental leave, family friendly employment and care for the child. This prospective longitudinal research was of 124 Australian expectant first-time mothers who completed questionnaires in their third trimester of pregnancy, and again at six and twelve months postpartum. First-time expectant mothers' decisions regarding engaging in paid work and selecting care for their child represent those of a group who are invested in motherhood and have usually had direct experience of engaging in paid work. They therefore provide an important insight into society’s idealised views about motherhood and the emotional and social uncertainty of making personal decisions where the consequences of such decisions are unknown. These decisions reflect public beliefs about the role of women in contributing to the country’s productivity and decisions about providing for the economic and emotional care needs of their family. As so little is known about the reasoning and processes of decision-making of women’s choices regarding paid work and care of the child this research was designed to capture expectant first-time mother’s preferred options for engaging in paid work and the care of their child, and investigate their actual decisions made at six and 12 months postpartum. To capture preferred options, decisions and outcomes of decisions regarding paid work and care of the child a prospective longitudinal research design was utilised. This design had three important components that addressed key limitations in the extant literature. First the research commenced in pregnancy in order to investigate preferences and beliefs about paid work and care and to examine baseline data that may influence decisions made as the women returned to paid work. Second the research involved longitudinal tracking from the antenatal time point to six and 12 months postpartum in order to identify the influences on decisions made. Third the research measured outcomes of the decisions made at each time point. This research examined the intentions, preferences, beliefs, influences, and outcomes of the decisions about engagement in paid work and choice of care. The analyses examined factors predicting return to paid work, the timing of return and extent of engagement in paid work; the care for the child; satisfaction with paid work; satisfaction with care for the child, motherhood and fulfilment; and maternal wellbeing at six and 12 months postpartum. The factors of interest were both rational/economic (availability and extent of paid and unpaid maternity leave; flexible work patterns) and emotional/affective (career satisfaction, investment in motherhood, and concern with quality of care for the child). Results indicated a group preference, and realisation for, return to paid work within the first year after the birth of a child but with reduction in hours to part-time. Most women saw paid work not only as a source of income but also as source of personal satisfaction. There were four key themes arising from this research. First, the women strived to feel emotionally secure when deciding about engaging in paid work and care of the child. To achieve emotional security women made their decisions for paid work and care of the child differently. A woman’s decision for maternal employment is a function of her personal beliefs, preferences and context regarding paid work and care of the child. She adjusts her established work identity with her new identity as a mother. The second key theme from this research is that the women made their decisions for maternal employment in response to their personal context and there were different levels of opportunities between the women’s choices. There is inequity of entitlement regarding work conditions associated with a woman’s education level. This has implications for the woman’s engagement in paid work, and her child’s health and wellbeing. The third key theme is that the quality of the child’s care mattered to the women in the research. They preferred care provided by parents and/or relatives more than any other types of care. The fourth key theme identified that satisfaction and wellbeing outcomes experienced as a result of maternal employment decisions were a complex interaction between multiple factors that change across time with the ongoing development of the mother’s identity, and the development of the child. The implications for policy within Australia are that the employment of mothers in the workforce necessitates that non-parental care becomes a public concern, where there is universal access to good quality affordable care for every child, not just for those who can afford it. This is equitable and represents real choice while supporting the rights of the child (Thorpe, Cloney & Tayler, 2010), protecting and promoting the public interest (Cleveland & Krashinsky, 2010). Children’s health and wellbeing will be supported (Moore & Oberklaid, 2010) while children are in non-parental care, and they will be exposed to environments and experiences that support their learning and development. The significant design of the research enabled the trajectories of first-time expectant women to be tracked from the antenatal point to 12 months postpartum. But there were limitations: the small sample size, the over-representation of the sample being highly educated and the nature of a longitudinal research that is set within the economic, social and political context at that time. These limitations are discussed in relation to suggestions for future research.

Utility of routine data sources for feedback on the quality of cancer care: an assessment based on clinical practice guidelines

Background Not all cancer patients receive state-of-the-art care and providing regular feedback to clinicians might reduce this problem. The purpose of this study was to assess the utility of various data sources in providing feedback on the quality of cancer care. Methods Published clinical practice guidelines were used to obtain a list of processes-of-care of interest to clinicians. These were assigned to one of four data categories according to their availability and the marginal cost of using them for feedback. Results Only 8 (3%) of 243 processes-of-care could be measured using population-based registry or administrative inpatient data (lowest cost). A further 119 (49%) could be measured using a core clinical registry, which contains information on important prognostic factors (e.g., clinical stage, physiological reserve, hormone-receptor status). Another 88 (36%) required an expanded clinical registry or medical record review; mainly because they concerned long-term management of disease progression (recurrences and metastases) and 28 (11.5%) required patient interview or audio-taping of consultations because they involved information sharing between clinician and patient. Conclusion The advantages of population-based cancer registries and administrative inpatient data are wide coverage and low cost. The disadvantage is that they currently contain information on only a few processes-of-care. In most jurisdictions, clinical cancer registries, which can be used to report on many more processes-of-care, do not cover smaller hospitals. If we are to provide feedback about all patients, not just those in larger academic hospitals with the most developed data systems, then we need to develop sustainable population-based data systems that capture information on prognostic factors at the time of initial diagnosis and information on management of disease progression.

Evaluating multivariate volatility forecasts : how effective are statistical and economic loss functions?

Multivariate volatility forecasts are an important input in many financial applications, in particular portfolio optimisation problems. Given the number of models available and the range of loss functions to discriminate between them, it is obvious that selecting the optimal forecasting model is challenging. The aim of this thesis is to thoroughly investigate how effective many commonly used statistical (MSE and QLIKE) and economic (portfolio variance and portfolio utility) loss functions are at discriminating between competing multivariate volatility forecasts. An analytical investigation of the loss functions is performed to determine whether they identify the correct forecast as the best forecast. This is followed by an extensive simulation study examines the ability of the loss functions to consistently rank forecasts, and their statistical power within tests of predictive ability. For the tests of predictive ability, the model confidence set (MCS) approach of Hansen, Lunde and Nason (2003, 2011) is employed. As well, an empirical study investigates whether simulation findings hold in a realistic setting. In light of these earlier studies, a major empirical study seeks to identify the set of superior multivariate volatility forecasting models from 43 models that use either daily squared returns or realised volatility to generate forecasts. This study also assesses how the choice of volatility proxy affects the ability of the statistical loss functions to discriminate between forecasts. Analysis of the loss functions shows that QLIKE, MSE and portfolio variance can discriminate between multivariate volatility forecasts, while portfolio utility cannot. An examination of the effective loss functions shows that they all can identify the correct forecast at a point in time, however, their ability to discriminate between competing forecasts does vary. That is, QLIKE is identified as the most effective loss function, followed by portfolio variance which is then followed by MSE. The major empirical analysis reports that the optimal set of multivariate volatility forecasting models includes forecasts generated from daily squared returns and realised volatility. Furthermore, it finds that the volatility proxy affects the statistical loss functions’ ability to discriminate between forecasts in tests of predictive ability. These findings deepen our understanding of how to choose between competing multivariate volatility forecasts.

Managing the project learning paradox : a set-theoretic approach toward project knowledge transfer

Managing project-based learning is becoming an increasingly important part of project management. This article presents a comparative case study of 12 cases of knowledge transfer between temporary inter-organizational projects and permanent parent organizations. Our set-theoretic analysis of these data yields two major findings. First, a high level of absorptive capacity of the project owner is a necessary condition for successful project knowledge transfer, which implies that the responsibility for knowledge transfer seems to in the first place lie with the project parent organization, not with the project manager. Second, none of the factors are sufficient by themselves. This implies that successful project knowledge transfer is a complex process always involving configurations of multiple factors. We link these implications with the view of projects as complex temporary organizational forms in which successful project managers need to cope with complexity by simultaneously paying attention to both relational and organizational processes.

The undirected feedback vertex set problem has a Poly(k) Kernel

Resolving a noted open problem, we show that the Undirected Feedback Vertex Set problem, parameterized by the size of the solution set of vertices, is in the parameterized complexity class Poly(k), that is, polynomial-time pre-processing is sufficient to reduce an initial problem instance (G, k) to a decision-equivalent simplified instance (G', k') where k' � k, and the number of vertices of G' is bounded by a polynomial function of k. Our main result shows an O(k11) kernelization bound.

An examination of the predictors of blood donors' intentions to donate during two phases of an avian influenza outbreak

BACKGROUND: Data from prior health scares suggest that an avian influenza outbreak will impact on people’s intention to donate blood; however research exploring this is scarce. Using an augmented theory of planned behavior (TPB), incorporating threat perceptions alongside the rational decision-making components of the TPB, the current study sought to identify predictors of blood donors’ intentions to donate during two phases of an avian influenza outbreak. STUDY DESIGN AND METHODS: Blood donors (N = 172) completed an on-line survey assessing the standard TPB predictors as well as measures of threat perceptions from the health belief model (HBM; i.e., perceived susceptibility and severity). Path analyses examined the utility of the augmented TPB to predict donors’ intentions to donate during a low- and high-risk phase of an avian influenza outbreak. RESULTS: In both phases, the model provided a good fit to the data explaining 69% (low risk) and 72% (high risk) of the variance in intentions. Attitude, subjective norm, and perceived susceptibility significantly predicted donor intentions in both phases. Within the low-risk phase, gender was an additional significant predictor of intention, while in the high-risk phase, perceived behavioral control was significantly related to intentions. CONCLUSION: An augmented TPB model can be used to predict donors’ intentions to donate blood in a low-risk and a high-risk phase of an outbreak of avian influenza. As such, the results provide important insights into donors’ decision-making that can be used by blood agencies to maintain the blood supply in the context of an avian influenza outbreak.

Beyond MOF constraints : multiple constraint set metamodelling for lifecycle management

The management of models over time in many domains requires different constraints to apply to some parts of the model as it evolves. Using EMF and its meta-language Ecore, the development of model management code and tools usually relies on the meta- model having some constraints, such as attribute and reference cardinalities and changeability, set in the least constrained way that any model user will require. Stronger versions of these constraints can then be enforced in code, or by attaching additional constraint expressions, and their evaluations engines, to the generated model code. We propose a mechanism that allows for variations to the constraining meta-attributes of metamodels, to allow enforcement of different constraints at different lifecycle stages of a model. We then discuss the implementation choices within EMF to support the validation of a state-specific metamodel on model graphs when changing states, as well as the enforcement of state-specific constraints when executing model change operations.

Improving self-report measures of speeding

There is continuing debate regarding the psychometric properties of self-report measures of behaviour, particularly in road safety research. Practical considerations often preclude the use of objective assessments, leading to reliance on self-report measures. Acknowledging that such measures are likely to remain commonly used, this pilot project sought not to argue whether self-report measures should continue to be used, but to explore factors associated with how individuals respond to self-reported speeding measures. This paper reports preliminary findings from a qualitative study (focus groups and in-depth interviews) conducted with licensed drivers to explore the operational utility of self-reported speeding behaviour measures. Drawing upon concepts from the Theory of Planned Behaviour (TPB; Ajzen, 1991) and Agency Theory (Bandura, 2001), we identified four dimensions of self-reported speeding: including timeframe, speed zone, degree over the speed limit and, overall frequency of the behaviour, and examined participants’ perceptions of the operational utility of these factors. Issues related to comprehensibility, perceived accuracy, response format and layout were also explored. Results indicated that: heterogeneity in the timeframe of behavioural reflections suggests a need to provide a set timeframe for participants to consider when thinking about their previous speeding behaviour; response categories and formats should be carefully considered to ensure the most accurate representations of the frequency and degree of speeding are captured; the need to clearly articulate “low-level” speeding on self-report measures; and, that self-reports of speeding behaviour are typically context-irrelevant unless stipulated in the question. Limitations and directions for further research are discussed.

Philosophy, behaviour disorders, and the school

The recent exponential rise in the number of behaviour disorders has been the focus of a wide range of commentaries, ranging from the pedagogic and the administrative, to the sociological, and even the legal. This book will be the first to apply, in a systematic and thorough manner, the ideas of the foundational discipline of philosophy. A number of philosophical tools are applied here, tools arising through the medium of the traditional philosophical debates, such as those concerning governance, truth, logic, ethics, free-will, law and language. Each forms a separate chapter, but together they constitute a comprehensive, rigorous and original insight into what is now an important set of concerns for all those interested in the governance of children. The intention is threefold: first, to demonstrate the utility, accessibility and effectiveness of philosophical ideas within this important academic area. Philosophy does not have to be regarded an arcane and esoteric discipline, with only limited contemporary application, far from it. Second, the book offers a new set of approaches and ideas for both researchers and practitioners within education, a field is in danger of continually using the same ideas, to endlessly repeat the same conclusions. Third, the book offers a viable alternative to the dominant psychological model which increasingly employs pathology as its central rationale for conduct. The book would not only be of interest to mainstream educators, and to those students and academics interested in philosophy, and more specifically, the application of philosophical ideas to educational issues, it would also be an appropriate text for courses on education and difference, and due to the breadth of the philosophical issues addressed, courses on applied philosophy.