Sequential decision fusion of multibiometrics applied to text-dependent speaker verification for controlled errors

Reliability of the performance of biometric identity verification systems remains a significant challenge. Individual biometric samples of the same person (identity class) are not identical at each presentation and performance degradation arises from intra-class variability and inter-class similarity. These limitations lead to false accepts and false rejects that are dependent. It is therefore difficult to reduce the rate of one type of error without increasing the other. The focus of this dissertation is to investigate a method based on classifier fusion techniques to better control the trade-off between the verification errors using text-dependent speaker verification as the test platform. A sequential classifier fusion architecture that integrates multi-instance and multisample fusion schemes is proposed. This fusion method enables a controlled trade-off between false alarms and false rejects. For statistically independent classifier decisions, analytical expressions for each type of verification error are derived using base classifier performances. As this assumption may not be always valid, these expressions are modified to incorporate the correlation between statistically dependent decisions from clients and impostors. The architecture is empirically evaluated by applying the proposed architecture for text dependent speaker verification using the Hidden Markov Model based digit dependent speaker models in each stage with multiple attempts for each digit utterance. The trade-off between the verification errors is controlled using the parameters, number of decision stages (instances) and the number of attempts at each decision stage (samples), fine-tuned on evaluation/tune set. The statistical validation of the derived expressions for error estimates is evaluated on test data. The performance of the sequential method is further demonstrated to depend on the order of the combination of digits (instances) and the nature of repetitive attempts (samples). The false rejection and false acceptance rates for proposed fusion are estimated using the base classifier performances, the variance in correlation between classifier decisions and the sequence of classifiers with favourable dependence selected using the 'Sequential Error Ratio' criteria. The error rates are better estimated by incorporating user-dependent (such as speaker-dependent thresholds and speaker-specific digit combinations) and class-dependent (such as clientimpostor dependent favourable combinations and class-error based threshold estimation) information. The proposed architecture is desirable in most of the speaker verification applications such as remote authentication, telephone and internet shopping applications. The tuning of parameters - the number of instances and samples - serve both the security and user convenience requirements of speaker-specific verification. The architecture investigated here is applicable to verification using other biometric modalities such as handwriting, fingerprints and key strokes.

The health information practices of people living with chronic health conditions: Implications for health literacy

The reduction of the health literacy concept to a functional relationship with text, does not acknowledge the range of information sources that people draw from in order to make informed decision about their health and treatment. Drawing from two studies that explored how people with two different but complex and life-threatening chronic health conditions, chronic kidney disease and HIV, a socio-cultural understanding of the practise of health literacy is described. Health information is experienced by patients as a chronic health condition landscape, and develops from three information sources; namely epistemic, social and corporeal sources. Participants in both studies used activities that involved orienting, sharing and creating information to map this landscape which was used to inform their decision-making. These findings challenge the traditional conceptions of health literacy and suggest an approach that views the landscape of chronic illness as being socially, physically and contextually constructed. This approach necessitates a recasting of health literacy away from a sole interest in skills and towards understanding how information practices facilitate people becoming health literate.

Constructing the shitting citizen : the promise of scatological art as environmental and social activism

Art activism uses visual and performance art to promote social and environmental agendas. In this paper, I explore attempts to raise awareness of sanitation issues at the global, local and personal level using scatological art. I focus on the successes of the open-air public art exhibition set up in the Brisbane (Queensland, Australia) central business district to celebrate World Toilet Day in 2008. The art in this exhibition featured included one hundred toilets decorated to raise awareness of global sanitation issues and the distribution of promotional materials featuring scatological images including postcards and stickers. Given the subject matter and intent, the toilet art and promotional materials presented at the One Hundred Toilet exhibition can be seen as an example of scatological art employed for the purposes of social and environmental activism. Through the One Hundred Toilet exhibition, I consider the political aims and activist potential of using scatological art to progress social and environmental agendas and consider how this kind of ‘shit on show’ approach can contribute to the construction of the shitting citizen; one who is simultaneously responsible for and responsive to managing the waste that they produce and recognising and responding to broader sanitation issues.

Reconstructing places and spaces in blended work integrated learning

This paper considers the emergence and ongoing development of an embedded, studentnegotiated work placement model of Work Integrated Learning (WIL) in the engineering and built environment disciplines at an Australian metropolitan university. The characteristics of the model and a continuous improvement strategy are provided. The model is characterised by large student cohorts independently sourcing and negotiating relevant work placements and completing at least one, mandatory credit-bearing WIL unit. Through ongoing analyses and evaluation of the model more experiential and collaborative learning approaches have been adopted. This has included the creation of blended learning spaces using technology. The paper focuses on the five year journey travelled by the teaching team as they embarked on ways to improve curriculum, pedagogy, administrative processes and assessment - effectively relocating much of their interaction with students online. The insights derived from this rich, single case study should be of interest to others considering alternative ways of responding to increasing student enrolments in WIL and the impact of blended learning in this context.

Impairment of simulated motorcycle riding performance under low dose alcohol

Crash statistics that include the blood alcohol concentration (BAC) of vehicle operators reveal that crash involved motorcyclists are over represented at low BACs (e.g., ≤0.05%). This riding simulator study compared riding performance and hazard response under three low dose alcohol conditions (sober, 0.02% BAC, 0.05% BAC). Forty participants (20 novice, 20 experienced) completed simulated rides in urban and rural scenarios while responding to a safety-critical peripheral detection task (PDT). Results showed a significant increase in the standard deviation of lateral position in the urban scenario and PDT reaction time in the rural scenario under 0.05% BAC compared with zero alcohol. Participants were most likely to collide with an unexpected pedestrian in the urban scenario at 0.02% BAC, with novice participants at a greater relative risk than experienced riders. Novices chose to ride faster than experienced participants in the rural scenario regardless of BAC. Not all results were significant, emphasising the complex situation of the effects of low dose BAC on riding performance, which needs further research. The results of this simulator study provide some support for a legal BAC for motorcyclists below 0.05%.

Decision making guidelines for sustainable construction of industrialised building systems

The construction industry has an obligation to respond to sustainability expectations of our society. Solutions that integrate innovative, intelligent and sustainability deliverables are vital for us to meet new and emerging challenges. Industrialised Building Systems (IBS), or known otherwise as prefabrication, employs a combination of ready-made components in the construction of buildings. They promote quality of production, enhance simplification of construction processes and minimise waste. The unique characteristics of this construction method respond well to sustainability. Despite the promises however, IBS has yet to be effectively implemented in Malaysia. There are often misconceptions among key stakeholders about IBS applications. The existing rating schemes fail to assess IBS against sustainability measures. To ensure the capture of full sustainability potential in buildings developed, the critical factors and action plans agreeable to all participants in the development processes need to be identified. Through questionnaire survey, eighteen critical factors relevant to IBS sustainability were identified and encapsulated into a conceptual framework to coordinate a systematic IBS decision making approach. Five categories were used to separate the critical factors into: ecological performance; economic value; social equity and culture; technical quality; and implementation and enforcement. This categorisation extends the "Triple Bottom Lines" to include social, economic, environmental and institutional dimensions. Semi-structured interviews help identify strategies of actions and solutions of potential problems through a SWOT analysis framework. These tools help the decision-makers maximise the opportunities by using available strengths, avoid weaknesses, and diagnose possible threats in the examined issues. The recommendations formed an integrated action plan to present information on what and how to improve sustainability through tackling each critical factor during IBS development. It can be used as part of the project briefing documents for IBS designers. For validation and finalisation the research deliverables, three case studies were conducted. The research fills a current gap by responding to IBS project scenarios in developing countries. It also provides a balanced view for designers to better understand sustainability potential and prioritize attentions to manage sustainability issues in IBS applications.

Personalized ontology learning for enhancing text mining effectiveness

Over the last decade, the majority of existing search techniques is either keyword- based or category-based, resulting in unsatisfactory effectiveness. Meanwhile, studies have illustrated that more than 80% of users preferred personalized search results. As a result, many studies paid a great deal of efforts (referred to as col- laborative filtering) investigating on personalized notions for enhancing retrieval performance. One of the fundamental yet most challenging steps is to capture precise user information needs. Most Web users are inexperienced or lack the capability to express their needs properly, whereas the existent retrieval systems are highly sensitive to vocabulary. Researchers have increasingly proposed the utilization of ontology-based tech- niques to improve current mining approaches. The related techniques are not only able to refine search intentions among specific generic domains, but also to access new knowledge by tracking semantic relations. In recent years, some researchers have attempted to build ontological user profiles according to discovered user background knowledge. The knowledge is considered to be both global and lo- cal analyses, which aim to produce tailored ontologies by a group of concepts. However, a key problem here that has not been addressed is: how to accurately match diverse local information to universal global knowledge. This research conducts a theoretical study on the use of personalized ontolo- gies to enhance text mining performance. The objective is to understand user information needs by a \bag-of-concepts" rather than \words". The concepts are gathered from a general world knowledge base named the Library of Congress Subject Headings. To return desirable search results, a novel ontology-based mining approach is introduced to discover accurate search intentions and learn personalized ontologies as user profiles. The approach can not only pinpoint users' individual intentions in a rough hierarchical structure, but can also in- terpret their needs by a set of acknowledged concepts. Along with global and local analyses, another solid concept matching approach is carried out to address about the mismatch between local information and world knowledge. Relevance features produced by the Relevance Feature Discovery model, are determined as representatives of local information. These features have been proven as the best alternative for user queries to avoid ambiguity and consistently outperform the features extracted by other filtering models. The two attempt-to-proposed ap- proaches are both evaluated by a scientific evaluation with the standard Reuters Corpus Volume 1 testing set. A comprehensive comparison is made with a num- ber of the state-of-the art baseline models, including TF-IDF, Rocchio, Okapi BM25, the deploying Pattern Taxonomy Model, and an ontology-based model. The gathered results indicate that the top precision can be improved remarkably with the proposed ontology mining approach, where the matching approach is successful and achieves significant improvements in most information filtering measurements. This research contributes to the fields of ontological filtering, user profiling, and knowledge representation. The related outputs are critical when systems are expected to return proper mining results and provide personalized services. The scientific findings have the potential to facilitate the design of advanced preference mining models, where impact on people's daily lives.

Effects of mobile phone distraction on drivers’ reaction times

Distraction resulting from mobile phone use whilst driving has been shown to increase the reaction times of drivers, thereby increasing the likelihood of a crash. This study compares the effects of mobile phone conversations on reaction times of drivers responding to traffic events that occur at different points in a driver’s field of view. The CARRS-Q Advanced Driving Simulator was used to test a group of young drivers on various simulated driving tasks including a traffic event that occurred within the driver’s central vision—a lead vehicle braking suddenly—and an event that occurred within the driver’s peripheral—a pedestrian entering a zebra crossing from a footpath. Thirty-two licensed drivers drove the simulator in three phone conditions: baseline (no phone conversation), and while engaged in hands-free and handheld phone conversations. The drivers were aged between 21 to 26 years and split evenly by gender. Differences in reaction times for an event in a driver’s central vision were not statistically significant across phone conditions, probably due to a lower speed selection by the distracted drivers. In contrast, the reaction times to detect an event that originated in a distracted driver’s peripheral vision were more than 50% longer compared to the baseline condition. A further statistical analysis revealed that deterioration of reaction times to an event in the peripheral vision was greatest for distracted drivers holding a provisional licence. Many critical events originate in a driver’s periphery, including vehicles, bicyclists, and pedestrians emerging from side streets. A reduction in the ability to detect these events while distracted presents a significant safety concern that must be addressed.

The value of health and wellbeing : an empirical model of value creation in social marketing

Purpose The purpose of this paper is to investigate the role of multiple actors in the value creation process for a preventative health service, and observe the subsequent impact on key service outcomes of satisfaction and customer behaviour intentions to use a preventative health service again in the future. Design/methodology/approach An online self-completion survey of Australian women (n=797) was conducted to test the proposed framework in the context of a free, government-provided breastscreening service. Data were analysed using Structural Equation Modelling (SEM). Findings The findings indicate that functional and emotional value are created from organisational and customer resources. These findings indicate that health service providers and customers are jointly responsible for the successful creation of value, leading to desirable outcomes for all stakeholders. Practical implications The results highlight to health professionals the aspects of service that can be managed in order to create value with target audiences. The findings also indicate the importance of the resources provided by users in the creation of value, signifying the importance of customer education and management. Originality/value This study provides a significant contribution to social marketing through the provision of an empirically validated model of value creation in a preventative health service. The model demonstrates how the creation and provision of value can lead to the achievement of desirable social behaviours - a key aim of social marketing.

Differential entrainment of neuroelectric delta oscillations in developmental dyslexia

Oscillatory entrainment to the speech signal is important for language processing, but has not yet been studied in developmental disorders of language. Developmental dyslexia, a difficulty in acquiring efficient reading skills linked to difficulties with phonology (the sound structure of language), has been associated with behavioural entrainment deficits. It has been proposed that the phonological ‘deficit’ that characterises dyslexia across languages is related to impaired auditory entrainment to speech at lower frequencies via neuroelectric oscillations (<10 Hz, ‘temporal sampling theory’). Impaired entrainment to temporal modulations at lower frequencies would affect the recovery of the prosodic and syllabic structure of speech. Here we investigated event-related oscillatory EEG activity and contingent negative variation (CNV) to auditory rhythmic tone streams delivered at frequencies within the delta band (2 Hz, 1.5 Hz), relevant to sampling stressed syllables in speech. Given prior behavioural entrainment findings at these rates, we predicted functionally atypical entrainment of delta oscillations in dyslexia. Participants performed a rhythmic expectancy task, detecting occasional white noise targets interspersed with tones occurring regularly at rates of 2 Hz or 1.5 Hz. Both groups showed significant entrainment of delta oscillations to the rhythmic stimulus stream, however the strength of inter-trial delta phase coherence (ITC, ‘phase locking’) and the CNV were both significantly weaker in dyslexics, suggestive of weaker entrainment and less preparatory brain activity. Both ITC strength and CNV amplitude were significantly related to individual differences in language processing and reading. Additionally, the instantaneous phase of prestimulus delta oscillation predicted behavioural responding (response time) for control participants only.

The cultural impact of institutional remix : the formalisation of textual reappropriation within the ABC

In 2009, Mark Deuze proposed an updated approach to media studies to incorporate ‘media life’, a concept he suggests addresses the invisibleness of ubiquitous media. Media life provides a useful lens for researchers to understand the human condition in media and not with media. At a similar time, public service media (PSM) strategies have aligned audience participation with the so‐called Reithian trinity which suggest the PSB should inform, educate and entertain while performing its core values of public service broadcasting (Enli 2008). Remix within the PSM institution relies on audience participation, employing ‘the people formerly known as the audience’ (Rosen 2006) as cultural artifact producers, and draws on their experience from within the media. Remix as a practice then enables us to examine the shift of the core PSM values by understanding how audience participation, informed by a human condition mobilised from our existence of being in media and not merely with media. However, remix within PSM challenges the once elitist construction of meaning models with an egalitarian approach towards socially reappropriated texts, questioning its affect on the cultural landscape. This paper draws on three years of ethnographic data from within the Australian Broadcasting Corporation (ABC), exploring the remix culture of ABC Pool. ABC Pool operates under a Creative Commons licensing regime to enable remix practice under the auspices of the ABC. ABC Pool users provide a useful group of remix practitioners to examine as they had access to a vast ABC archival collection and were invited to remix those cultural artefacts, often adding cultural and fiscal value. This paper maintains a focus on the audience participation within PSM through remix culture by applying media dependency theory to remix as cultural practice and calls to expand and update the societal representation within the ABC.

The role of defects, or active states, in surface electrochemistry with particular reference to gold in neutral solution

Metastable, active, or nonequilibrium states due to the presence of abnormal structures and various types of defects are well known in metallurgy. The role of such states at gold surfaces in neutral aqueous media (an important electrode system in the microsensor area) was explored using cyclic voltammetry. It was demonstrated that, as postulated in earlier work from this laboratory, there is a close relationship between premonolayer oxidation, multilayer hydrous oxide reduction and electrocatalytic behaviour in the case of this and other metal electrode systems. Some of the most active, and therefore most important, entities at surfaces (e.g., metal adatoms) are not readily imageable or detectable by high resolution surface microscopy techniques. Cyclic voltammetry, however, provides significant, though not highly specific, information about such species. The main conclusion is that further practical and theoretical work on active states of metal surfaces is highly desirable as their behaviour is not simple and is of major importance in many electrocatalytic processes.

A facile chemical screening method for the detection of stress corrosion cracking in 9 carat gold alloys

Stress corrosion cracking (SCC) is a well known form of environmental attack in low carat gold jewellery. It is desirable to have a quick, easy and cost effective way to detect SCC in alloys and prevent them from being used and later failing in their application. A facile chemical method to investigate SCC of 9 carat gold alloys is demonstrated. It involves a simple application of tensile stress to a wire sample in a corrosive environment such as 1–10 % FeCl3 which induces failure in less than 5 minutes. In this study three quaternary (Au, Ag, Cu and Zn) 9 carat gold alloy compositions were investigated for their resistance to SCC and the relationship between time to failure and processing conditions is studied. It is envisaged that the use of such a rapid and facile screening procedure at the production stage may readily identify alloy treatments that produce jewellery that will be susceptible to SCC in its lifetime.

The health effects of temperature : current estimates, future projections, and adaptation strategies

Climate change is expected to be one of the biggest global health threats in the 21st century. In response to changes in climate and associated extreme events, public health adaptation has become imperative. This thesis examined several key issues in this emerging research field. The thesis aimed to identify the climate-health (particularly temperature-health) relationships, then develop quantitative models that can be used to project future health impacts of climate change, and therefore help formulate adaptation strategies for dealing with climate-related health risks and reducing vulnerability. The research questions addressed by this thesis were: (1) What are the barriers to public health adaptation to climate change? What are the research priorities in this emerging field? (2) What models and frameworks can be used to project future temperature-related mortality under different climate change scenarios? (3) What is the actual burden of temperature-related mortality? What are the impacts of climate change on future burden of disease? and (4) Can we develop public health adaptation strategies to manage the health effects of temperature in response to climate change? Using a literature review, I discussed how public health organisations should implement and manage the process of planned adaptation. This review showed that public health adaptation can operate at two levels: building adaptive capacity and implementing adaptation actions. However, there are constraints and barriers to adaptation arising from uncertainty, cost, technologic limits, institutional arrangements, deficits of social capital, and individual perception of risks. The opportunities for planning and implementing public health adaptation are reliant on effective strategies to overcome likely barriers. I proposed that high priorities should be given to multidisciplinary research on the assessment of potential health effects of climate change, projections of future health impacts under different climate and socio-economic scenarios, identification of health cobenefits of climate change policies, and evaluation of cost-effective public health adaptation options. Heat-related mortality is the most direct and highly-significant potential climate change impact on human health. I thus conducted a systematic review of research and methods for projecting future heat-related mortality under different climate change scenarios. The review showed that climate change is likely to result in a substantial increase in heatrelated mortality. Projecting heat-related mortality requires understanding of historical temperature-mortality relationships, and consideration of future changes in climate, population and acclimatisation. Further research is needed to provide a stronger theoretical framework for mortality projections, including a better understanding of socioeconomic development, adaptation strategies, land-use patterns, air pollution and mortality displacement. Most previous studies were designed to examine temperature-related excess deaths or mortality risks. However, if most temperature-related deaths occur in the very elderly who had only a short life expectancy, then the burden of temperature on mortality would have less public health importance. To guide policy decisions and resource allocation, it is desirable to know the actual burden of temperature-related mortality. To achieve this, I used years of life lost to provide a new measure of health effects of temperature. I conducted a time-series analysis to estimate years of life lost associated with changes in season and temperature in Brisbane, Australia. I also projected the future temperaturerelated years of life lost attributable to climate change. This study showed that the association between temperature and years of life lost was U-shaped, with increased years of life lost on cold and hot days. The temperature-related years of life lost will worsen greatly if future climate change goes beyond a 2 °C increase and without any adaptation to higher temperatures. The excess mortality during prolonged extreme temperatures is often greater than the predicted using smoothed temperature-mortality association. This is because sustained period of extreme temperatures produce an extra effect beyond that predicted by daily temperatures. To better estimate the burden of extreme temperatures, I estimated their effects on years of life lost due to cardiovascular disease using data from Brisbane, Australia. The results showed that the association between daily mean temperature and years of life lost due to cardiovascular disease was U-shaped, with the lowest years of life lost at 24 °C (the 75th percentile of daily mean temperature in Brisbane), rising progressively as temperatures become hotter or colder. There were significant added effects of heat waves, but no added effects of cold spells. Finally, public health adaptation to hot weather is necessary and pressing. I discussed how to manage the health effects of temperature, especially with the context of climate change. Strategies to minimise the health effects of high temperatures and climate change can fall into two categories: reducing the heat exposure and managing the health effects of high temperatures. However, policy decisions need information on specific adaptations, together with their expected costs and benefits. Therefore, more research is needed to evaluate cost-effective adaptation options. In summary, this thesis adds to the large body of literature on the impacts of temperature and climate change on human health. It improves our understanding of the temperaturehealth relationship, and how this relationship will change as temperatures increase. Although the research is limited to one city, which restricts the generalisability of the findings, the methods and approaches developed in this thesis will be useful to other researchers studying temperature-health relationships and climate change impacts. The results may be helpful for decision-makers who develop public health adaptation strategies to minimise the health effects of extreme temperatures and climate change.

Gifted students with a reading disability : the impact of lived experience

Gifted students who have a reading disability have learning characteristics that set them apart from their peers. The ability to read impacts upon all areas of the formal curriculum in which print-based texts are common. Therefore, the full intellectual development of gifted students with a reading disability can be repressed because their access to learning opportunities is reduced. When the different learning needs caused by concomitant giftedness and reading disability are not met, it can have serious implications for both academic achievement and the social-emotional wellbeing of these students. In order to develop a deeper understanding of this vulnerable group of students, this study investigated the learning characteristics of gifted students with a reading disability. Furthermore, it investigated how the learning characteristics of these students impact upon their lived experiences. Since achievement and motivation have been shown to be closely linked to self-efficacy, self-efficacy theory underpinned the conceptual framework of the study. The study used a descriptive case study approach to document the lived experiences of gifted students with a reading disability. Nine participants aged between 11 and 18, who were formally identified as gifted with a reading disability, took part in the study. Data sources in the case study database included: cognitive assessments, such as WISC assessments, Stanford Binet 5, or the Raven's Standard Progressive Matrices; the WIAT II reading assessment; the Reader Self-Perception Scale; document reviews; parent and teacher checklists designed to gain information about the students' learning characteristics; and semi-structured interviews with students. The study showed that gifted students with a reading disability display a complex profile of learning strengths and weaknesses. As a result, they face a daily struggle of trying to reconcile the confusion of being able to complete some tasks to a high level, while struggling to read. The study sheds light on the myriad of issues faced by the students at school. It revealed that when the particular learning characteristics and needs of gifted students with a reading disability are recognised and met, these students can experience academic success, and avoid the serious social-emotional complications cited in previous studies. Indeed, rather than suffering from depression, disengagement from learning, and demotivation, these students were described as resilient, independent, determined, goal oriented and motivated to learn and persevere. Notably, the students in the study had developed effective coping strategies for dealing with the daily challenges they faced. These strategies are outlined in the thesis together with the advice students offered for helping other gifted students with a reading disability to succeed. Their advice is significant for all teachers who wish to nurture the potential of those students who face the challenge of being gifted with a reading disability, and for the parents of these students. This research advances knowledge pertaining to the theory of self-efficacy, and self-efficacy in reading specifically, by showing that although gifted students with a reading disability have low self-efficacy, the level is not the same for all aspects of reading. Furthermore, despite low self-efficacy in reading these students remained motivated. The study also enhances existing knowledge in the areas of gifted education and special education because it documents the lived experience of gifted students with a specific learning disability in reading from the students' perspectives. Based on a synthesis of the literature and research findings, an Inclusive Pathway Model is proposed that describes a framework to support gifted students with a reading disability so that they might achieve, and remain socially and emotionally well-adjusted. The study highlights the importance of clear identification protocols (such as the use of a range of assessment sources, discussions with students and parents, and an awareness of the characteristics of gifted students with a reading disability) and support mechanisms for assisting students (for example, differentiated reading instruction and the use of assistive technology).