An efficient tagging data interpretation and representation scheme for item recommendation

A tag-based item recommendation method generates an ordered list of items, likely interesting to a particular user, using the users past tagging behaviour. However, the users tagging behaviour varies in different tagging systems. A potential problem in generating quality recommendation is how to build user profiles, that interprets user behaviour to be effectively used, in recommendation models. Generally, the recommendation methods are made to work with specific types of user profiles, and may not work well with different datasets. In this paper, we investigate several tagging data interpretation and representation schemes that can lead to building an effective user profile. We discuss the various benefits a scheme brings to a recommendation method by highlighting the representative features of user tagging behaviours on a specific dataset. Empirical analysis shows that each interpretation scheme forms a distinct data representation which eventually affects the recommendation result. Results on various datasets show that an interpretation scheme should be selected based on the dominant usage in the tagging data (i.e. either higher amount of tags or higher amount of items present). The usage represents the characteristic of user tagging behaviour in the system. The results also demonstrate how the scheme is able to address the cold-start user problem.

Setting measureable goals with young people : qualitative feedback from the Goal Attainment Scale in youth mental health

Introduction Measuring occupational performance is an essential part of clinical practice; however, there is little research on service user perceptions of measures. The aim of this investigation was to explore the acceptability and utility of one occupational performance outcome measure, Goal Attainment Scaling, with young people (12–25 years old) seeking psychological help. Method Semi-structured interviews were conducted with ten young people seeking help from a youth mental health clinic. Interviews were audio taped and a field diary kept. Interviews were transcribed verbatim and analysed using content analysis. Results were verified by member checking. Results All participants were able to engage in using Goal Attainment Scaling to set goals for therapy, and reported the process to be useful. The participants identified the physical location and ownership of the scale was important to help motivate them to work on their goals. Conclusion Young help-seekers see Goal Attainment Scaling as an acceptable tool to facilitate the establishment of functional goals. Young service users were particularly keen to maintain control over the physical location of completed forms.

Reliable Fault Diagnosis for Low-Speed Bearings Using Individually Trained Support Vector Machines With Kernel Discriminative Feature Analysis

This paper proposes a highly reliable fault diagnosis approach for low-speed bearings. The proposed approach first extracts wavelet-based fault features that represent diverse symptoms of multiple low-speed bearing defects. The most useful fault features for diagnosis are then selected by utilizing a genetic algorithm (GA)-based kernel discriminative feature analysis cooperating with one-against-all multicategory support vector machines (OAA MCSVMs). Finally, each support vector machine is individually trained with its own feature vector that includes the most discriminative fault features, offering the highest classification performance. In this study, the effectiveness of the proposed GA-based kernel discriminative feature analysis and the classification ability of individually trained OAA MCSVMs are addressed in terms of average classification accuracy. In addition, the proposedGA- based kernel discriminative feature analysis is compared with four other state-of-the-art feature analysis approaches. Experimental results indicate that the proposed approach is superior to other feature analysis methodologies, yielding an average classification accuracy of 98.06% and 94.49% under rotational speeds of 50 revolutions-per-minute (RPM) and 80 RPM, respectively. Furthermore, the individually trained MCSVMs with their own optimal fault features based on the proposed GA-based kernel discriminative feature analysis outperform the standard OAA MCSVMs, showing an average accuracy of 98.66% and 95.01% for bearings under rotational speeds of 50 RPM and 80 RPM, respectively.

Probabilistic power system contingency analysis considering wind

This thesis was a step forward in developing probabilistic assessment of power system response to faults subject to intermittent generation by renewable energy. It has investigated the wind power fluctuation effect on power system stability, and the developed fast estimation process has demonstrated the feasibility for real-time implementation. A better balance between power network security and efficiency can be achieved based on this research outcome.

Side Channel Analysis of Some Hash Based MACs: A Response to SHA-3 Requirements

The forthcoming NIST’s Advanced Hash Standard (AHS) competition to select SHA-3 hash function requires that each candidate hash function submission must have at least one construction to support FIPS 198 HMAC application. As part of its evaluation, NIST is aiming to select either a candidate hash function which is more resistant to known side channel attacks (SCA) when plugged into HMAC, or that has an alternative MAC mode which is more resistant to known SCA than the other submitted alternatives. In response to this, we perform differential power analysis (DPA) on the possible smart card implementations of some of the recently proposed MAC alternatives to NMAC (a fully analyzed variant of HMAC) and HMAC algorithms and NMAC/HMAC versions of some recently proposed hash and compression function modes. We show that the recently proposed BNMAC and KMDP MAC schemes are even weaker than NMAC/HMAC against the DPA attacks, whereas multi-lane NMAC, EMD MAC and the keyed wide-pipe hash have similar security to NMAC against the DPA attacks. Our DPA attacks do not work on the NMAC setting of MDC-2, Grindahl and MAME compression functions.

Eigenvalue Analysis of a DFIG Based Wind Power System under Different Modes of Operations

This chapter discussed the various modes of operation of the Doubly Fed Induction Generator (DFIG) based wind farm system. The impact of a auxiliary damping controller on the different modes of operation for the DFIG based wind generation system is investigated. The co-ordinated tuning of the damping controller to enhance the damping of the oscillatory modes using Bacteria Foraging (BF) technique is presented. The results from eigenvalue analysis are presented to elucidate the effectiveness of the tuned damping controller in the DFIG system under Super/Sub-synchronous speed of operation. The robustness issue of the damping controller is also investigated.

Stability analysis and implementation of Power-Hardware-in-the-Loop for power system testing

This project develops the required guidelines to assure stable and accurate operation of Power-Hardware-in-the-Loop implementations. The proposals of this research have been theoretically analyzed and practically examined using a Real-Time Digital Simulator. In this research, the interaction between software simulated power network and the physical power system has been studied. The conditions for different operating regimes have been derived and the corresponding analyses have been presented.

Analysis of impedance matched circuit for wireless power transfer

Typical wireless power transfer systems utilize series compensation circuit which is based on magnetic coupling and resonance principles that was first developed by Tesla. However, changes in coupling caused by gap distance, alignment and orientation variations can lead to reduce power transfer efficiencies and the transferred power levels. This paper proposes impedance matched circuit to reduce frequency bifurcation effect and improve on the transferred power level, efficiency and total harmonic distortion (THD) performance of the series compensation circuit. A comprehensive mathematical analysis is performed for both series and impedance matched circuits to show the frequency bifurcation effects in terms of input impedance, variations in transferred power levels and efficiencies. Matlab/Simulink results validate the theoretical analysis and shows the circuits’ THD performance when circuits are fed with power electronic converters.

Efficiency of parallelisation of genetic algorithms in the data analysis context

Most real-life data analysis problems are difficult to solve using exact methods, due to the size of the datasets and the nature of the underlying mechanisms of the system under investigation. As datasets grow even larger, finding the balance between the quality of the approximation and the computing time of the heuristic becomes non-trivial. One solution is to consider parallel methods, and to use the increased computational power to perform a deeper exploration of the solution space in a similar time. It is, however, difficult to estimate a priori whether parallelisation will provide the expected improvement. In this paper we consider a well-known method, genetic algorithms, and evaluate on two distinct problem types the behaviour of the classic and parallel implementations.

Literacy, place, and pedagogies of possibility: Working against residualization effects and deficit discourses in poor school communities

Australia has a long history of policy attention to the education of poor and working-class youth (Connell, 1994), yet currently on standardized educational outcomes measures the gaps are widening in ways that relate to social background, including race, location and class. An economic analysis of school choice in Australia reveals that a high proportion of government school students now come from lower Socio-Economic Status (SES) backgrounds (Ryan & Watson, 2004), indicating a trend towards a gradual residualisation of the poor in government schools, with increased private school enrolments as a confirmed national trend. The spatial distribution of poverty and the effects on school populations are not unique to Australia (Lupton, 2003; Lipman, 2011; Ryan, 2010). Raffo and colleagues (2010) recently provided a synthesis of socially critical approaches towards schooling and poverty arguing that what is needed are shifts in the balances of power to reposition those within the educational system as having some say in the ways schooling is organized. ‘Disadvantaged’ primary schools are not a marginal concern for education systems, but now account for a large and growing number of schools that serve an ever increasing population being made redundant, in part-time precarious work, under-employed or unemployed (Thomson 2002; Smyth, Down et al 2010). In Australia, the notion of the ‘disadvantaged’ school now refers to those, mostly public schools, being residualised by a politics of parental choice that drives neoliberalising policy logic (Bonner & Caro 2007; Hattam & Comber, forthcoming 2014; Thomson & Reid, 2003)...

Regressive measures won’t help youth into work or training

The 2014 federal budget implemented a so-called crackdown on what Minister for Social Services Kevin Andrews calls young people who are content to “sit on the couch at home and pick up a welfare cheque”. The crackdown will change access to income support for people under 30 years of age. From January 1 2015, all young people seeking Newstart Allowance and Youth Allowance for the first time will be required to “demonstrate appropriate job search and participation in employment services support for six months before receiving payments”. Upon qualifying, recipients must then spend 25 hours per week in Work for the Dole in order to receive income support for a six-month period. What happens beyond this six months is unclear. What is clear is that these policy changes, together with the Minister’s accompanying statements, are informed by a deficit view of disadvantaged youth. It is a view that demonstrates how little politicians know or understand about these young peoples’ past circumstances.

Interrogating policy contradictions in literacy reforms about persuasive texts

Objectives Our overarching objective is to demonstrate the political contradictions about about how persuasive texts should be taught in the middle years of schooling, analysing two contradictory Australian wide educational reforms. We consider the complexities of power and access to literacy for students in relation to these reforms about the privileged genre of persuasion. Our work is framed by our appreciation of literacy as a social justice issue, and the notion of students’ pedagogic rights (Bernstein, 2000). Specifically, we introduce and analyse the knowledge and skills about persuasive text sanctioned by the Australian high-stakes test, the National Assessment Program for Literacy and Numeracy (NAPLAN), for students in the middle years of schooling (ACARA, 2013). We compare this to the contemporary emphasis on multimodal persuasive texts sanctioned by the recently released Australian Curriculum English (ACARA, 2014). We conclude our analysis by identifying biases in the structure of particular knowledges and the inherent threats to democracy.

Nigeria's power sector: Analysis of productivity

Nigerian electricity market is characterized by inadequate electricity generation framework, compounded by lack of timely routine maintenances. This results in significant deterioration in plant electricity output. This study analyzes the productivity changes in the Nigerian power sector. Productivity increased on average in the power sector by the adoption of new technologies from best-practice power plants. The assumption of Hicks neutral technological change is found not to be suitable for the Nigerian power sector. This study finds that the plants are not using their capacity meaningfully, instead, there is a tendency to use labor.

Stochastic analysis of a radial-inflow turbine in the presence of parametric uncertainties

This paper presents an uncertainty quantification study of the performance analysis of the high pressure ratio single stage radial-inflow turbine used in the Sundstrand Power Systems T-100 Multi-purpose Small Power Unit. A deterministic 3D volume-averaged Computational Fluid Dynamics (CFD) solver is coupled with a non-statistical generalized Polynomial Chaos (gPC) representation based on a pseudo-spectral projection method. One of the advantages of this approach is that it does not require any modification of the CFD code for the propagation of random disturbances in the aerodynamic and geometric fields. The stochastic results highlight the importance of the blade thickness and trailing edge tip radius on the total-to-static efficiency of the turbine compared to the angular velocity and trailing edge tip length. From a theoretical point of view, the use of the gPC representation on an arbitrary grid also allows the investigation of the sensitivity of the blade thickness profiles on the turbine efficiency. The gPC approach is also applied to coupled random parameters. The results show that the most influential coupled random variables are trailing edge tip radius coupled with the angular velocity.

The persistence of predictors of wellbeing among refugee youth eight years after resettlement in Melbourne, Australia

This short report assesses the predictors of subjective health and happiness among a cohort of refugee youth over their first eight years in Australia. Five waves of data collection were conducted between 2004 (n=120) and 2012–13 (n=51) using mixed methods. Previous schooling,self-esteem, moving house in the previous year, a supportive social environment, stronger ethnic identity and perceived discrimination were significant predictors of wellbeing after adjusting for demographic and pre-migration factors. When compared with a previous analysis of this cohort over their first three years of settlement, experiences of social exclusion still have a significant impact on wellbeing eight years after arriving in Australia. This study contributes to mounting evidence in support of policies that discourage discrimination and promote social inclusion and cultural diversity and which underpin the wellbeing of resettled refugee youth.