Degradation modeling and monitoring of machines using operation-specific hidden Markov models

In this paper, a novel data-driven approach to monitoring of systems operating under variable operating conditions is described. The method is based on characterizing the degradation process via a set of operation-specific hidden Markov models (HMMs), whose hidden states represent the unobservable degradation states of the monitored system while its observable symbols represent the sensor readings. Using the HMM framework, modeling, identification and monitoring methods are detailed that allow one to identify a HMM of degradation for each operation from mixed-operation data and perform operation-specific monitoring of the system. Using a large data set provided by a major manufacturer, the new methods are applied to a semiconductor manufacturing process running multiple operations in a production environment.

Dopamine transporter genotype predicts behavioural and neural measures of response inhibition

The ability to inhibit unwanted actions is a heritable executive function that may confer risk to disorders such as attention deficit hyperactivity disorder (ADHD). Converging evidence from pharmacology and cognitive neuroscience suggests that response inhibition is instantiated within frontostriatal circuits of the brain with patterns of activity that are modulated by the catecholamines dopamine and noradrenaline. A total of 405 healthy adult participants performed the stop-signal task, a paradigmatic measure of response inhibition that yields an index of the latency of inhibition, termed the stop-signal reaction time (SSRT). Using this phenotype, we tested for genetic association, performing high-density single-nucleotide polymorphism mapping across the full range of autosomal catecholamine genes. Fifty participants also underwent functional magnetic resonance imaging to establish the impact of associated alleles on brain and behaviour. Allelic variation in polymorphisms of the dopamine transporter gene (SLC6A3: rs37020; rs460000) predicted individual differences in SSRT, after corrections for multiple comparisons. Furthermore, activity in frontal regions (anterior frontal, superior frontal and superior medial gyri) and caudate varied additively with the T-allele of rs37020. The influence of genetic variation in SLC6A3 on the development of frontostriatal inhibition networks may represent a key risk mechanism for disorders of behavioural inhibition.

Using patient specific finite element models to understand the biomechanics of paediatric spinal deformity surgery

Adolescent idiopathic scoliosis (AIS) is a spinal deformity, which may require surgical correction by attaching rods to the patient’s spine using screws inserted into the vertebrae. Complication rates for deformity correction surgery are unacceptably high. Determining an achievable correction without overloading the adjacent spinal tissues or implants requires an understanding of the mechanical interaction between these components. We have developed novel patient specific modelling software to create individualized finite element models (FEM) representing the thoracolumbar spine and ribcage of scoliosis patients. We are using these models to better understand the biomechanics of spinal deformity correction.

What are pregnant women told about models of maternity care in Australia? A retrospective study of women's reports

Objective To describe women’s reports of the model of care options General Practitioners (GPs) discussed with them at the first pregnancy consultation and women’s self-reported role in decisionmaking about model of care. Methods Women who had recently given birth responded to survey items about the models of care GPs discussed, their role in final decision-making, and socio-demographic, obstetric history, and early pregnancy characteristics. Results The proportion of women with whom each model of care was discussed varied between 8.2% (for private midwifery care with home birth) and 64.4% (GP shared care). Only 7.7% of women reported that all seven models were discussed. Exclusive discussion about private obstetric care and about all public models was common, and women’s health insurance status was the strongest predictor of the presence of discussions about each model. Most women (82.6%) reported active involvement in final decision-making about model of care. Conclusion Although most women report involvement in maternity model of care decisions, they remain largely uninformed about the breadth of available model of care options. Practical implications Strategies that facilitate women’s access to information on the differentiating features and outcomes for all models of care should be prioritized to better ensure equitable and quality decisions.

An improved gate driver for power MOSFETs using a cascode configuration

To overcome the limitations of existing gate drive topologies an improved gate drive concept is proposed to provide fast, controlled switching of power MOSFETs. The proposed topology exploits the cascode configuration with the inclusion of an active gate clamp to ensure that the driven MOSFET may be turned off under all load conditions. Key operating principles and advantages of the proposed gate drive topology are discussed. Characteristic waveforms are investigated via simulation and experimentation for the cascode driver in an inductive switching application at 375V and 10A. Experimental waveforms compared well with simulations with long gate charging delays (including the Miller plateau) being eliminated from the gate voltage waveform.

An application of the Driver Behaviour Questionnaire in a large Australian organisational fleeting setting : can it predict crashes and demerit point loss?

This study reports on the utilisation of the Manchester Driver Behaviour Questionnaire (DBQ) to examine the self-reported driving behaviours of a large sample of Australian fleet drivers (N = 3414). Surveys were completed by employees before they commenced a one day safety workshop intervention. Factor analysis techniques identified a three factor solution similar to previous research, which was comprised of: (a) errors, (b) highway-code violations and (c) aggressive driving violations. Two items traditionally related with highway-code violations were found to be associated with aggressive driving behaviours among the current sample. Multivariate analyses revealed that exposure to the road, errors and self-reported offences predicted crashes at work in the last 12 months, while gender, highway violations and crashes predicted offences incurred while at work. Importantly, those who received more fines at work were at an increased risk of crashing the work vehicle. However, overall, the DBQ demonstrated limited efficacy at predicting these two outcomes. This paper outlines the major findings of the study in regards to identifying and predicting aberrant driving behaviours and also highlights implications regarding the future utilisation of the DBQ within fleet settings.

Specialist versus generic models of psychiatry training and service provision for people with intellectual disabilities

Background  Models of service provision and professional training differ between countries. This study aims to investigate a specialist intellectual disabilities model and a generic mental health model, specifically comparing psychiatrists’ knowledge and competencies, and service quality and accessibility in meeting the mental health needs of people with intellectual disabilities. Method  Data were collected from consultant and trainee psychiatrists within a specialist intellectual disabilities model (UK) and a generic mental health model (Australia). Results  The sample sizes were 294 (UK) and 205 (Australia). Statistically significant differences were found, with UK participants having positive views about the specialist intellectual disabilities service model they worked within, demonstrating flexible and accessible working practices and service provision, responsive to the range of mental health needs of the population with intellectual disabilities, and providing a wide range of treatments and supports. The UK participants were knowledgeable, well trained and confident in their work. They wanted to work with people with intellectual disabilities. In all of these areas, the converse was found from the Australian generic mental health service model. Conclusions  The specialist intellectual disabilities model of service provision and training has advantages over the generic mental health model.

Designing channels for brand value : four meta-models

Channels are becoming an increasingly important area for companies to innovate, specifically as they provide direct points of contact with their customers. However, little is known in regards to multi-channel strategies that embody strategic brand values and how customers experience these channels collectively. The purpose of this paper is to investigate how organisations configure multi- channel strategies to communicate their brand value and experience to their customers. Data was collated from sixty companies through a content analysis methodology within the retail sector. Results uncovered commonalities through the identification of four meta-models surrounding common brand values, intended emotive experience, individual channels and the customer segment. These meta-models are titled: High Quality, Trust, Convenience and Community. This research also presents implications of a multi-channel design tool based on findings from this study to help reinforce company brand values and design an overall connected customer experience.

Melanopsin expressing intrinsically photosensitive Retinal Ganglion cells in retinal disease

Melanopsin containing intrinsically photosensitive Retinal Ganglion Cells (ipRGCs) are a class of photoreceptors with established roles in non-image forming processes. Their contributions to image forming vision may include the estimation of brightness. Animal models have been central for understanding the physiological mechanisms of ipRGC function and there is evidence of conservation of function across species. ipRGCs can be divided into 5 ganglion cell subtypes that show morphological and functional diversity. Research in humans has established that ipRGCs signal environmental irradiance to entrain the central body clock to the solar day for regulating circadian processes and sleep. In addition, ipRGCs mediate the pupil light reflex (PLR), making the PLR a readily accessible behavioural marker of ipRGC activity. Less is known about ipRGC function in retinal and optic nerve disease, with emerging research providing insight into their function in diabetes, retinitis pigmentosa, glaucoma and hereditary optic neuropathy. We briefly review the anatomical distributions, projections and basic physiological mechanisms of ipRGCs, their proposed and known functions in animals and humans with and without eye disease. We introduce a paradigm for differentiating inner and outer retinal inputs to the pupillary control pathway in retinal disease and apply this paradigm to patients with age-related macular degeneration (AMD). In these cases of patients with AMD, we provide the initial evidence that ipRGC function is altered, and that the dysfunction is more pronounced in advanced disease. Our perspective is that with refined pupillometry paradigms, the pupil light reflex can be extended to AMD assessment as a tool for the measurement of inner and outer retinal dysfunction.

Stop and revive? The effectiveness of nap and active rest breaks for reducing driver sleepiness

Objectives The purpose for this study was to determine the relative benefit of nap and active rest breaks for reducing driver sleepiness. Methods Participants were 20 healthy young adults (20-25 years), including 8 males and 12 females. A counterbalanced within-subjects design was used such that each participant completed both conditions on separate occasions, a week apart. The effects of the countermeasures were evaluated by established physiological (EEG theta and alpha absolute power), subjective (Karolinska Sleepiness Scale), and driving performance measures (Hazard Perception Task). Participants woke at 5am, and undertook a simulated driving task for two hours; each participant then had either a 15-minute nap opportunity or a 15-minute active rest break that included 10 minutes of brisk walking, followed by another hour of simulated driving. Results The nap break reduced EEG theta and alpha absolute power and eventually reduced subjective sleepiness levels. In contrast, the active rest break did not reduce EEG theta and alpha absolute power levels with the power levels eventually increasing. An immediate reduction of subjective sleepiness was observed, with subjective sleepiness increasing during the final hour of simulated driving. No difference was found between the two breaks for hazard perception performance. Conclusions Only the nap break produced a significant reduction in physiological sleepiness. The immediate reductions of subjective sleepiness following the active rest break could leave drivers with erroneous perceptions of their sleepiness, particularly as physiological sleepiness continued to increase after the break.

On-road driver sleepiness : what are Australian drivers experiences and awareness of sleepiness while driving?

Objectives: Driver sleepiness contributes substantially to road crash incidents. Simulator and on-road studies clearly reveal an impairing effect from sleepiness for driving ability. However, drivers might not appreciate the dangerousness of driving while sleepy and this could translate to their on-road driving behaviours. This study sought to determine drivers’ on-road experiences of sleepiness, their sleep habits, and personal awareness of the signs of sleepiness. Methods: Participants were a random selection of 92 drivers travelling on a major highway in the state of Queensland, Australia, who were stopped by Police as part of routine drink driving operations. Participants completed a brief questionnaire that included: demographic details, awareness and on-road experiences of sleepy driving, and sleep habits. A modified version of the Karolinska Sleepiness Scale (KSS) was used to assess subjective sleepiness during the last 15 minutes of driving. Results: Participants rating of subjective sleepiness was quite low with 90% reporting at or below 3 on the KSS. Participants were reasonably aware of the signs of sleepiness; with a number of these correlated with on-road experiences. The participants sleep debt correlated with their alertness (r = -.30) and the hours spent driving (r = .38). Conclusions: These results suggest that drivers had moderate or substantial experience of driving when sleepy and many were aware of the signs of sleepiness. As many of the participants reported driving long distances after suboptimal sleep durations, it is possible that their risk perception of the dangerousness of sleepy driving maybe erroneous.

Mathematical Models of Tumor-Immune System Dynamics

"This collection of papers offers a broad synopsis of state-of-the-art mathematical methods used in modeling the interaction between tumors and the immune system. These papers were presented at the four-day workshop on Mathematical Models of Tumor-Immune System Dynamics held in Sydney, Australia from January 7th to January 10th, 2013. The workshop brought together applied mathematicians, biologists, and clinicians actively working in the field of cancer immunology to share their current research and to increase awareness of the innovative mathematical tools that are applicable to the growing field of cancer immunology. Recent progress in cancer immunology and advances in immunotherapy suggest that the immune system plays a fundamental role in host defense against tumors and could be utilized to prevent or cure cancer. Although theoretical and experimental studies of tumor-immune system dynamics have a long history, there are still many unanswered questions about the mechanisms that govern the interaction between the immune system and a growing tumor. The multidimensional nature of these complex interactions requires a cross-disciplinary approach to capture more realistic dynamics of the essential biology. The papers presented in this volume explore these issues and the results will be of interest to graduate students and researchers in a variety of fields within mathematical and biological sciences."--Publisher website

The BRAKE Driver Awareness Program & Senior Health Education

The BRAKE Driver Awareness Program provides evidence-based behaviour, risk, attitude and knowledge education for young drivers. BRAKE was founded during 2006 by Queensland Police Sergeant Rob Duncan and has been delivered to more than 35,000 senior secondary students since 2007. BRAKE is a participant directed program supported by resources provided at no cost. It includes eight parts able to be delivered in different configurations. BRAKE is endorsed by the Queensland Police and Queensland Ambulance Services. It is recognised by the Queensland Studies Authority as a Queensland Certificate of Education registered life skills course. This session is a must attend for secondary teachers, coordinators, staff in senior leadership positions and other stakeholders seeking a unique approach to adolescent road safety education. It will conclude with an opportunity to consider how BRAKE can be integrated into the senior secondary Health Education curriculum or pastoral care, social action and personal development programs.

Integrating the impact of climate into event based failure models for water pipes

This paper presents an event-based failure model to predict the number of failures that occur in water distribution assets. Often, such models have been based on analysis of historical failure data combined with pipe characteristics and environmental conditions. In this paper weather data have been added to the model to take into account the commonly observed seasonal variation of the failure rate. The theoretical basis of existing logistic regression models is briefly described in this paper, along with the refinements made to the model for inclusion of seasonal variation of weather. The performance of these refinements is tested using data from two Australian water authorities.