Tag based collaborative filtering for recommender systems

Collaborative tagging can help users organize, share and retrieve information in an easy and quick way. For the collaborative tagging information implies user’s important personal preference information, it can be used to recommend personalized items to users. This paper proposes a novel tag-based collaborative filtering approach for recommending personalized items to users of online communities that are equipped with tagging facilities. Based on the distinctive three dimensional relationships among users, tags and items, a new similarity measure method is proposed to generate the neighborhood of users with similar tagging behavior instead of similar implicit ratings. The promising experiment result shows that by using the tagging information the proposed approach outperforms the standard user and item based collaborative filtering approaches.

Review : Why study the media ?

Silverstone’s Why Study the Media? (hereafter WSM) is a dif� cult book to review, especially in such a short space. The content spans millennia of theoretical, analytical and historical perspectives on our media, but is none the less entirely contemporary and relevant in its focus. Silverstone’s perspective is at times elusive because the book sets out, successfully I think, to answer the question posed in the title. But it does so by raising major questions in media studies, important questions, in a way that does not imply quick and easy answers.

Unstructured strategic decision-making processes : CRE decision-making in the Italian consulting industry

This thesis aims at developing a better understanding of unstructured strategic decision making processes and the conditions for achieving successful decision outcomes. Specifically it focuses on the processes used to make CRE (Corporate Real Estate) decisions. The starting point for this thesis is that our knowledge of such processes is incomplete. A comprehensive study of the most recent CRE literature together with Behavioural Organization Theory has provided a research framework for the exploration of CRE recommended =best practice‘, and of how organizational variables impact on and shape these practices. To reveal the fundamental differences between CRE decision-making in practice and the prescriptive =best practice‘ advocated in the CRE literature, a study of seven Italian management consulting firms was undertaken addressing the aspects of content and process of decisions. This thesis makes its primary contribution by identifying the importance and difficulty of finding the right balance between problem complexity, process richness and cohesion to ensure a decision-making process that is sufficiently rich and yet quick enough to deliver a prompt outcome. While doing so, this research also provides more empirical evidence to some of the most established theories of decision-making while reinterpreting their mono-dimensional arguments in a multi-dimensional model of successful decision-making.

Variation of the Stiles-Crawford effect with accommodation and myopia

Background: Mechanical forces either due to accommodation or myopia may stretch the retina and/or cause shear between the retina and choroid. This can be investigated by making use of the Stiles-Crawford effect (SCE), which is the phenomenon of light changing in apparent brightness as it enters through different positions in the pupil. The SCE can be measured by psychophysical and objective techniques, with the SCE parameters being directionality (rate of change across the pupil), and orientation (the location of peak sensitivity in the pupil). Aims: 1. To study the changes in foveal SCE with accommodation in emmetropes and myopes using a subjective (psychophysical) technique. 2. To develop and evaluate a quick objective technique of measuring the SCE using the multifocal electroretinogram. Methods: The SCE was measured in 6 young emmetropes and 6 young myopes for up to 8 D accommodation stimulus with a psychophysical technique and its variants. An objective technique using the multifocal electroretinogram was developed and evaluated with 5 emmetropes. Results: Using the psychophysical technique, the SCE directionality increased by similar amounts in both emmetropes and myopes as accommodation increased, with an increase of 15-20% with 6 D of accommodation. However, there were no significant orientation changes. Additional measurements showed that most of the change in the directionality was probably an artefact of optical factors such as higher-order aberrations and accommodative lag rather a true effect of accommodation. The multifocal technique demonstrated the presence of the SCE, but results were noisy and too variable to detect any changes in SCE directionality or orientation with accommodation. Conclusion: There is little true change in the SCE with accommodation responses up to 6 D in either emmetropes or myopes, although it is possible that substantial changes might occur at very high accommodation levels. The objective technique using the multifocal electroretinogram was quicker and less demanding for the subjects than the psychophysical technique, but as implemented in this thesis, it is not a reliable method of measuring the SCE.

Involvement of target contrast in visual masking location tasks deficients in myopia

Purpose: There have been few studies of visual temporal processing of myopic eyes. This study investigated the visual performance of emmetropic and myopic eyes using a backward visual masking location task. Methods: Data were collected for 39 subjects (15 emmetropes, 12 stable myopes, 12 progressing myopes). In backward visual masking, a target’s visibility is reduced by a mask presented in quick succession ‘after’ the target. The target and mask stimuli were presented at different interstimulus intervals (from 12 to 300 ms). The task involved locating the position of a target letter with both a higher (seven per cent) and a lower (five per cent) contrast. Results: Emmetropic subjects had significantly better performance for the lower contrast location task than the myopes (F2,36 = 22.88; p < 0.001) but there was no difference between the progressing and stable myopic groups (p = 0.911). There were no differences between the groups for the higher contrast location task (F2,36 = 0.72, p = 0.495). No relationship between task performance and either the magnitude of myopia or axial length was found for either task. Conclusions: A location task deficit was observed in myopes only for lower contrast stimuli. Both emmetropic and myopic groups had better performance for the higher contrast task compared to the lower contrast task, with myopes showing considerable improvement. This suggests that five per cent contrast may be the contrast threshold required to bias the task towards the magnocellular system (where myopes have a temporal processing deficit). Alternatively, the task may be sensitive to the contrast sensitivity of the observer.

View from a bridge : what makes a musical city

The attention paid by the British music press in 1976 to the release of The Saints first single “I’m Stranded” was the trigger for a commercial and academic interest in the Brisbane music scene which still has significant energy. In 2007, Brisbane was identifed by Billboard Magazine as a “hot spot” of independent music. A place to watch. Someone turned a torch on this town, had a quick look, moved on. But this town has always had music in it. Some of it made by me. So, I’m taking this connection of mine, and working it into a contextual historical analysis of the creative lives of Brisbane musicians. I will be interviewing a number of Brisbane musicians. These interviews have begun, and will continue to be be conducted in 2011/2012. I will ask questions and pursue memories that will encompass family, teenage years, siblings, the suburbs, the city, venues, television and radio; but then widen to welcome the river, the hills and mountains, foes and friends, beliefs and death. The wider research will be a contextual historical analysis of the creative lives of Brisbane musicians. It will explore the changing nature of their work practices over time and will consider the notion, among other factors, of ‘place’ in both their creative practice and their creative output. It will also examine how the presence of the practitioners and their work is seen to contribute to the cultural life of the city and the creative lives of its citizens into the future. This paper offers an analysis of this last notion: how does this city see its music-makers? In addition to the interviews, over 300 Brisbane musicians were surveyed in September 2009 as part of a QUT-initiated recorded music event (BIGJAM). Their responses will inform the production of this paper.

Theoretical investigation of mechanisms of formation and interaction of nanoparticles

In this thesis an investigation into theoretical models for formation and interaction of nanoparticles is presented. The work presented includes a literature review of current models followed by a series of five chapters of original research. This thesis has been submitted in partial fulfilment of the requirements for the degree of doctor of philosophy by publication and therefore each of the five chapters consist of a peer-reviewed journal article. The thesis is then concluded with a discussion of what has been achieved during the PhD candidature, the potential applications for this research and ways in which the research could be extended in the future. In this thesis we explore stochastic models pertaining to the interaction and evolution mechanisms of nanoparticles. In particular, we explore in depth the stochastic evaporation of molecules due to thermal activation and its ultimate effect on nanoparticles sizes and concentrations. Secondly, we analyse the thermal vibrations of nanoparticles suspended in a fluid and subject to standing oscillating drag forces (as would occur in a standing sound wave) and finally on lattice surfaces in the presence of high heat gradients. We have described in this thesis a number of new models for the description of multicompartment networks joined by a multiple, stochastically evaporating, links. The primary motivation for this work is in the description of thermal fragmentation in which multiple molecules holding parts of a carbonaceous nanoparticle may evaporate. Ultimately, these models predict the rate at which the network or aggregate fragments into smaller networks/aggregates and with what aggregate size distribution. The models are highly analytic and describe the fragmentation of a link holding multiple bonds using Markov processes that best describe different physical situations and these processes have been analysed using a number of mathematical methods. The fragmentation of the network/aggregate is then predicted using combinatorial arguments. Whilst there is some scepticism in the scientific community pertaining to the proposed mechanism of thermal fragmentation,we have presented compelling evidence in this thesis supporting the currently proposed mechanism and shown that our models can accurately match experimental results. This was achieved using a realistic simulation of the fragmentation of the fractal carbonaceous aggregate structure using our models. Furthermore, in this thesis a method of manipulation using acoustic standing waves is investigated. In our investigation we analysed the effect of frequency and particle size on the ability for the particle to be manipulated by means of a standing acoustic wave. In our results, we report the existence of a critical frequency for a particular particle size. This frequency is inversely proportional to the Stokes time of the particle in the fluid. We also find that for large frequencies the subtle Brownian motion of even larger particles plays a significant role in the efficacy of the manipulation. This is due to the decreasing size of the boundary layer between acoustic nodes. Our model utilises a multiple time scale approach to calculating the long term effects of the standing acoustic field on the particles that are interacting with the sound. These effects are then combined with the effects of Brownian motion in order to obtain a complete mathematical description of the particle dynamics in such acoustic fields. Finally, in this thesis, we develop a numerical routine for the description of "thermal tweezers". Currently, the technique of thermal tweezers is predominantly theoretical however there has been a handful of successful experiments which demonstrate the effect it practise. Thermal tweezers is the name given to the way in which particles can be easily manipulated on a lattice surface by careful selection of a heat distribution over the surface. Typically, the theoretical simulations of the effect can be rather time consuming with supercomputer facilities processing data over days or even weeks. Our alternative numerical method for the simulation of particle distributions pertaining to the thermal tweezers effect use the Fokker-Planck equation to derive a quick numerical method for the calculation of the effective diffusion constant as a result of the lattice and the temperature. We then use this diffusion constant and solve the diffusion equation numerically using the finite volume method. This saves the algorithm from calculating many individual particle trajectories since it is describes the flow of the probability distribution of particles in a continuous manner. The alternative method that is outlined in this thesis can produce a larger quantity of accurate results on a household PC in a matter of hours which is much better than was previously achieveable.

Porous polyurethane coatings bonded onto surface-modified titanium substrates for the growth of an endothelial cell layer

Cardiovascular diseases refer to the class of diseases that involve the heart or blood vessels (arteries and veins). Examples of medical devices for treating the cardiovascular diseases include ventricular assist devices (VADs), artificial heart valves and stents. Metallic biomaterials such as titanium and its alloy are commonly used for ventricular assist devices. However, titanium and its alloy show unacceptable thrombosis, which represents a major obstacle to be overcome. Polyurethane (PU) polymer has better blood compatibility and has been used widely in cardiovascular devices. Thus one aim of the project was to coat a PU polymer onto a titanium substrate by increasing the surface roughness, and surface functionality. Since the endothelium of a blood vessel has the most ideal non-thrombogenic properties, it was the target of this research project to grow an endothelial cell layer as a biological coating based on the tissue engineering strategy. However, seeding endothelial cells on the smooth PU coating surfaces is problematic due to the quick loss of seeded cells which do not adhere to the PU surface. Thus it was another aim of the project to create a porous PU top layer on the dense PU pre-layer-coated titanium substrate. The method of preparing the porous PU layer was based on the solvent casting/particulate leaching (SCPL) modified with centrifugation. Without the step of centrifugation, the distribution of the salt particles was not uniform within the polymer solution, and the degree of interconnection between the salt particles was not well controlled. Using the centrifugal treatment, the pore distribution became uniform and the pore interconnectivity was improved even at a high polymer solution concentration (20%) as the maximal salt weight was added in the polymer solution. The titanium surfaces were modified by alkli and heat treatment, followed by functionlisation using hydrogen peroxide. A silane coupling agent was coated before the application of the dense PU pre-layer and the porous PU top layer. The ability of the porous top layer to grow and retain the endothelial cells was also assessed through cell culture techniques. The bonding strengths of the PU coatings to the modified titanium substrates were measured and related to the surface morphologies. The outcome of the project is that it has laid a foundation to achieve the strategy of endothelialisation for the blood compatibility of medical devices. This thesis is divided into seven chapters. Chapter 2 describes the current state of the art in the field of surface modification in cardiovascular devices such as ventricular assist devices (VADs). It also analyses the pros and cons of the existing coatings, particularly in the context of this research. The surface coatings for VADs have evolved from early organic/ inorganic (passive) coatings, to bioactive coatings (e.g. biomolecules), and to cell-based coatings. Based on the commercial applications and the potential of the coatings, the relevant review is focused on the following six types of coatings: (1) titanium nitride (TiN) coatings, (2) diamond-like carbon (DLC) coatings, (3) 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer coatings, (4) heparin coatings, (5) textured surfaces, and (6) endothelial cell lining. Chapter 3 reviews the polymer scaffolds and one relevant fabrication method. In tissue engineering, the function of a polymeric material is to provide a 3-dimensional architecture (scaffold) which is typically used to accommodate transplanted cells and to guide their growth and the regeneration of tissue. The success of these systems is dependent on the design of the tissue engineering scaffolds. Chapter 4 describes chemical surface treatments for titanium and titanium alloys to increase the bond strength to polymer by altering the substrate surface, for example, by increasing surface roughness or changing surface chemistry. The nature of the surface treatment prior to bonding is found to be a major factor controlling the bonding strength. By increasing surface roughness, an increase in surface area occurs, which allows the adhesive to flow in and around the irregularities on the surface to form a mechanical bond. Changing surface chemistry also results in the formation of a chemical bond. Chapter 5 shows that bond strengths between titanium and polyurethane could be significantly improved by surface treating the titanium prior to bonding. Alkaline heat treatment and H2O2 treatment were applied to change the surface roughness and the surface chemistry of titanium. Surface treatment increases the bond strength by altering the substrate surface in a number of ways, including increasing the surface roughness and changing the surface chemistry. Chapter 6 deals with the characterization of the polyurethane scaffolds, which were fabricated using an enhanced solvent casting/particulate (salt) leaching (SCPL) method developed for preparing three-dimensional porous scaffolds for cardiac tissue engineering. The enhanced method involves the combination of a conventional SCPL method and a step of centrifugation, with the centrifugation being employed to improve the pore uniformity and interconnectivity of the scaffolds. It is shown that the enhanced SCPL method and a collagen coating resulted in a spatially uniform distribution of cells throughout the collagen-coated PU scaffolds.In Chapter 7, the enhanced SCPL method is used to form porous features on the polyurethane-coated titanium substrate. The cavities anchored the endothelial cells to remain on the blood contacting surfaces. It is shown that the surface porosities created by the enhanced SCPL may be useful in forming a stable endothelial layer upon the blood contacting surface. Chapter 8 finally summarises the entire work performed on the fabrication and analysis of the polymer-Ti bonding, the enhanced SCPL method and the PU microporous surface on the metallic substrate. It then outlines the possibilities for future work and research in this area.

Planning and evaluation

Introduction: The core business of public health is to protect and promote health in the population. Public health planning is the means to maximise these aspirations. Health professionals develop plans to address contemporary health priorities as the evidence about changing patterns of mortality and morbidity is presented. Officials are also alert to international trends in patterns of disease that have the potential to affect the health of Australians. Integrated planning and preparation is currently underway involving all emergency health services, hospitals and population health units to ensure Australia's quick and efficient response to any major infectious disease outbreak, such as avian influenza (bird flu). Public health planning for the preparations for the Sydney Olympics and Paralympic Games in 2000 took almost three years. ‘Its major components included increased surveillance of communicable disease; presentations to sentinel emergency departments; medical encounters at Olympic venues; cruise ship surveillance; environmental and food safety inspections; bioterrorism surveillance and global epidemic intelligence’ (Jorm et al 2003, 102). In other words, the public health plan was developed to ensure food safety, hospital capacity, safe crowd control, protection against infectious diseases, and an integrated emergency and disaster plan. We have national and state plans for vaccinating children against infectious diseases in childhood; plans to promote dental health for children in schools; and screening programs for cervical, breast and prostate cancer. An effective public health response to a change in the distribution of morbidity and mortality requires planning. All levels of government plan for the public’s health. Local governments (councils) ensure healthy local environments to protect the public’s health. They plan parks for recreation, construct traffic-calming devices near schools to prevent childhood accidents, build shade structures and walking paths, and even embed drafts/chess squares in tables for people to sit and play. Environmental Health officers ensure food safety in restaurants and measure water quality. These public health measures attempt to promote the quality of life of residents. Australian and state governments produce plans that protect and promote health through various policy and program initiatives and innovations. To be effective, program plans need to be evaluated. However, building an integrated evaluation plan into a program plan is often forgotten, as planning and evaluation are seen as two distinct entities. Consequently, it is virtually impossible to measure, with any confidence, the extent to which a program has achieved its goals and objectives. This chapter introduces you to the concepts of public health program planning and evaluation. Case studies and reflection questions are presented to illustrate key points. As various authors use different terminology to describe the same concepts/actions of planning and evaluation, the glossary at the back of this book will help you to clarify the terms used in this chapter.

Preventing sexual violence?

This article critically assesses the main social policy responses to preventing rape following much feminist struggle to make sexual violence a public matter of legitimate concern. It considers the preventative potential of legal measures, anti-violence campaigns waged by feminist and men's groups in the US and Australia, public education campaigns in Schools and Universities, and public awareness campaigns sponsored by the state.We argue that sexual violence is not amenable to quick fix strategies that place responsibility for prevention entirely on individual men or women. While we recognise that responsibilising victims and individualising offenders is consistent with wider global shifts in social policy calling upon individuals to manage their own risk, we argue that the increasing reliance on such neo-liberal social policy is especially problematic in preventing rape. The paper suggests ways to resist this which place greater emphasis on the promotion of sexual ethics; the eroticisation of consent; the reinvention of the norms of romance to include both these, and the complete separation of the psycho-social-symbolic connections between sex and violence, and ultimately the re-evaluation of the cultural expectations of masculinity and femininity.

Selective growth of carbon nanotubes on bare silicon : MWNT sinthesys on patterned substrates without predeposition of metal catalyst

Carbon nanotubes (CNTs) are expected to become the ideal constituent of many technologes, in particular for future generation electronics. This considerable interest is due to their unique electrical and mechanical properties. They show indeed super-high current-carrying capacity, ballistic electron transport and good field-emission properties. Then, these superior features make CNTs the most promising building blocks for electronic devices, as organic solar cells and organic light emitting devices (OLED). By using Focused Ion Beam (FIB) patterning it is possible to a obtain a high control on position, relative distances and diameter of CNTs. The present work shows how to grow three-dimensional architecture made of vertical-aligned CNTs directly on silicon. Thanks to the higher activity of a pre-patterned surface the synthesis process results very quick, cheap and simple. Such large area growths of CNTs could be used in preliminary test for application as electrodes for organic solar cells.

An optimising compiler for generated tiny virtual machines

VMSCRIPT is a scripting language designed to allow small programs to be compiled for a range of generated tiny virtual machines, suitable for sensor network devices. The VMSCRIPT compiler is an optimising compiler designed to allow quick re-targeting, based on a template, code rewriting model. A compiler backend can be specified at the same time as a virtual machine, with the compiler reading the specification and using it as a code generator.

Introduction and Epilogue to Special Issue: Re-conceiving the artful in management development and education

The editorial focus of this issue is on artful, aesthetic and artistic endeavours in management. Being artful is not about arts-based quick fixes. In the context of this Special Issue, to be artful is to transform self through profound learning experiences that expand human consciousness, often facilitated by artistic processes. In management education and development this suggests a shift from instrumental management towards a paradigm of artful creation. Why the arts and artfulness? And why now? In what ways can the arts inform, inspire and leverage management development and education?

A secure framework and related protocols for ubiquitous access to electronic health records using Java sim cards

Ubiquitous access to patient medical records is an important aspect of caring for patient safety. Unavailability of sufficient medical information at the point-ofcare could possibly lead to a fatality. The U.S. Institute of Medicine has reported that between 44,000 and 98,000 people die each year due to medical errors, such as incorrect medication dosages, due to poor legibility in manual records, or delays in consolidating needed information to discern the proper intervention. In this research we propose employing emergent technologies such as Java SIM Cards (JSC), Smart Phones (SP), Next Generation Networks (NGN), Near Field Communications (NFC), Public Key Infrastructure (PKI), and Biometric Identification to develop a secure framework and related protocols for ubiquitous access to Electronic Health Records (EHR). A partial EHR contained within a JSC can be used at the point-of-care in order to help quick diagnosis of a patient’s problems. The full EHR can be accessed from an Electronic Health Records Centre (EHRC) when time and network availability permit. Moreover, this framework and related protocols enable patients to give their explicit consent to a doctor to access their personal medical data, by using their Smart Phone, when the doctor needs to see or update the patient’s medical information during an examination. Also our proposed solution would give the power to patients to modify the Access Control List (ACL) related to their EHRs and view their EHRs through their Smart Phone. Currently, very limited research has been done on using JSCs and similar technologies as a portable repository of EHRs or on the specific security issues that are likely to arise when JSCs are used with ubiquitous access to EHRs. Previous research is concerned with using Medicare cards, a kind of Smart Card, as a repository of medical information at the patient point-of-care. However, this imposes some limitations on the patient’s emergency medical care, including the inability to detect the patient’s location, to call and send information to an emergency room automatically, and to interact with the patient in order to get consent. The aim of our framework and related protocols is to overcome these limitations by taking advantage of the SIM card and the technologies mentioned above. Briefly, our framework and related protocols will offer the full benefits of accessing an up-to-date, precise, and comprehensive medical history of a patient, whilst its mobility will provide ubiquitous access to medical and patient information everywhere it is needed. The objective of our framework and related protocols is to automate interactions between patients, healthcare providers and insurance organisations, increase patient safety, improve quality of care, and reduce the costs.

Modeling, stability analysis and control of microgrid

With the increase in the level of global warming, renewable energy based distributed generators (DGs) will increasingly play a dominant role in electricity production. Distributed generation based on solar energy (photovoltaic and solar thermal), wind, biomass, mini-hydro along with use of fuel cells and micro turbines will gain considerable momentum in the near future. A microgrid consists of clusters of load and distributed generators that operate as a single controllable system. The interconnection of the DG to the utility/grid through power electronic converters has raised concern about safe operation and protection of the equipments. Many innovative control techniques have been used for enhancing the stability of microgrid as for proper load sharing. The most common method is the use of droop characteristics for decentralized load sharing. Parallel converters have been controlled to deliver desired real power (and reactive power) to the system. Local signals are used as feedback to control converters, since in a real system, the distance between the converters may make the inter-communication impractical. The real and reactive power sharing can be achieved by controlling two independent quantities, frequency and fundamental voltage magnitude. In this thesis, an angle droop controller is proposed to share power amongst converter interfaced DGs in a microgrid. As the angle of the output voltage can be changed instantaneously in a voltage source converter (VSC), controlling the angle to control the real power is always beneficial for quick attainment of steady state. Thus in converter based DGs, load sharing can be performed by drooping the converter output voltage magnitude and its angle instead of frequency. The angle control results in much lesser frequency variation compared to that with frequency droop. An enhanced frequency droop controller is proposed for better dynamic response and smooth transition between grid connected and islanded modes of operation. A modular controller structure with modified control loop is proposed for better load sharing between the parallel connected converters in a distributed generation system. Moreover, a method for smooth transition between grid connected and islanded modes is proposed. Power quality enhanced operation of a microgrid in presence of unbalanced and non-linear loads is also addressed in which the DGs act as compensators. The compensator can perform load balancing, harmonic compensation and reactive power control while supplying real power to the grid A frequency and voltage isolation technique between microgrid and utility is proposed by using a back-to-back converter. As utility and microgrid are totally isolated, the voltage or frequency fluctuations in the utility side do not affect the microgrid loads and vice versa. Another advantage of this scheme is that a bidirectional regulated power flow can be achieved by the back-to-back converter structure. For accurate load sharing, the droop gains have to be high, which has the potential of making the system unstable. Therefore the choice of droop gains is often a tradeoff between power sharing and stability. To improve this situation, a supplementary droop controller is proposed. A small signal model of the system is developed, based on which the parameters of the supplementary controller are designed. Two methods are proposed for load sharing in an autonomous microgrid in rural network with high R/X ratio lines. The first method proposes power sharing without any communication between the DGs. The feedback quantities and the gain matrixes are transformed with a transformation matrix based on the line R/X ratio. The second method involves minimal communication among the DGs. The converter output voltage angle reference is modified based on the active and reactive power flow in the line connected at point of common coupling (PCC). It is shown that a more economical and proper power sharing solution is possible with the web based communication of the power flow quantities. All the proposed methods are verified through PSCAD simulations. The converters are modeled with IGBT switches and anti parallel diodes with associated snubber circuits. All the rotating machines are modeled in detail including their dynamics.