Frequency, intensity and duration of physical tasks performed by Australian rural firefighters during bushfire suppression

The current study combined, for the first time, video footage of individual firefighters wearing heart rate monitors and personal GPS units to quantify the frequency, duration and intensity of tasks performed by Australian rural fire crews when. suppressing bushfires. Across the four fireground 'shifts', the firefighters performed 34 distinct fireground tasks. Per shift, the task frequency ranged from once (raking fireline in teams, carrying a quick fill pump) to 103 times {lateral repositioning of a 38-mm charged firehose) .. The tasks lasted between 4 ± 2 s (bowling out 3-8-mm firehose) and 461 ± 387 s (raking fireline in teams). The task intensity~ as measured by average heart rate ranged between 97 ± 16 beats·min-1 (55.7 ± 8.7. %HRmax) and 157 ± 15 beats·min-1 (86.2 ± 10.8 %HRmax)· The tasks were performed a speeds that ranged from 0.12 ± 0.08 m·s-1 (manual hose retraction of 38-mm charged firehose) to 0.79 ± 0.40 m·s-1 (carrying a 38-mm coiled hose). Tasks found to be simultaneously frequent, long and intense (or two of these three) are likely to form the basis for job-specific testing of Australian rural firefighters suppressing bushfires.

Human behavior recognition with generic exponential family duration modeling in the hidden semi-Markov model

The ability to learn and recognize human activities of daily living (ADLs) is important in building pervasive and smart environments. In this paper, we tackle this problem using the hidden semi-Markov model. We discuss the state-of-the-art duration modeling choices and then address a large class of exponential family distributions to model state durations. Inference and learning are efficiently addressed by providing a graphical representation for the model in terms of a dynamic Bayesian network (DBN). We investigate both discrete and continuous distributions from the exponential family (Poisson and Inverse Gaussian respectively) for the problem of learning and recognizing ADLs. A full comparison between the exponential family duration models and other existing models including the traditional multinomial and the new Coxian are also presented. Our work thus completes a thorough investigation into the aspect of duration modeling and its application to human activities recognition in a real-world smart home surveillance scenario.

Explicit state duration HMM for abnormality detection in sequences of human activity

The importance of explicit duration modelling for classification of sequences of human activity and the reliable and timely detection of duration abnormality was highlighted. The normal classes of behavior were designed to highlight the importance of modelling duration given the limitations of the tracking system. It was found that HMM was the weakest model for classification of the unseen normal sequences with 81% accuracy. Long term abnormality was investigated by artificially varying the duration of primary activity in a randomly selected test sequence. The incorporation of duration in models of human behavior is an important consideration for systems seeking to provide cognitive support and to detect deviation in the behavorial patterns.

Efficient Coxian duration modelling for activity recognition in smart environment with the hidden semi-Markov model

In this paper, we exploit the discrete Coxian distribution and propose a novel form of stochastic model, termed as the Coxian hidden semi-Makov model (Cox-HSMM), and apply it to the task of recognising activities of daily living (ADLs) in a smart house environment. The use of the Coxian has several advantages over traditional parameterization (e.g. multinomial or continuous distributions) including the low number of free parameters needed, its computational efficiency, and the existing of closed-form solution. To further enrich the model in real-world applications, we also address the problem of handling missing observation for the proposed Cox-HSMM. In the domain of ADLs, we emphasize the importance of the duration information and model it via the Cox-HSMM. Our experimental results have shown the superiority of the Cox-HSMM in all cases when compared with the standard HMM. Our results have further shown that outstanding recognition accuracy can be achieved with relatively low number of phases required in the Coxian, thus making the Cox-HSMM particularly suitable in recognizing ADLs whose movement trajectories are typically very long in nature.

Authorship and fixation in copyright law : a comparative comment

[The present comment considers an issue that has received little discussion in the common law world: namely whether fixation and authorship are parts of the same creative act in relation to literary, dramatic and musical works. The importance of the question is that, if authorship does not entail fixation, it should logically be possible for a person independent of the author to reduce the work to material form for copyright purposes. This would significantly expand the range of works protected by copyright and would extend protection to those works which have never been fixed by their authors. The focus of the comment is Australian law, but its discussion is comparative, with particular attention given to UK law.]

Epidemiologic merit of obese-years, the combination of degree and duration of obesity

This study aims to test the effect of combining the degree and the duration of obesity into a single variable-obese-years-and to examine whether obese-years is a better predictor of the risk of diabetes than simply body mass index (BMI) or duration of obesity. Of the original cohort of the Framingham Heart Study, 5,036 participants were followed up every 2 years for up to 48 years (from 1948). The variable, obese-years, was defined by multiplying for each participant the number of BMI units above 30 kg/m(2) by the number of years lived at that BMI. Associations with diabetes were analyzed by using time-dependent Cox proportional hazards regression models adjusted for potential confounders. The incidence of type-2 diabetes increased as the number of obese-years increased, with adjusted hazard ratios of 1.07 (95% confidence interval: 1.06, 1.09) per additional 10 obese-years. The dose-response relation between diabetes incidence and obese-years varied by sex and smoking status. The Akaike Information Criterion was lowest in the model containing obese-years compared with models containing either the degree or duration of obesity alone. A construct of obese-years is strongly associated with risk of diabetes and could be a better indicator of the health risks associated with increasing body weight than BMI or duration of obesity alone.

The duration of obesity and the risk of type-2 diabetes

Objective The evidence for the association between obesity and the risk of type 2 diabetes has been derived mainly from the analysis of the degree of obesity. The role of the duration of obesity as an independent risk has not been fully explored. The objective of the present study was to investigate the association between the duration of obesity and the risk of type 2 diabetes.

Design Prospective cohort study.

Setting The Framingham Heart Study (FHS), follow-up from 1948 to 1998.

Subjects A total of 1256 FHS participants who were free from type 2 diabetes at baseline, but were obese on at least two consecutive of the study’s twenty-four biennial examinations, were included. Type 2 diabetes status was collected throughout the 48 years of follow-up of the study. The relationship between duration of obesity and type 2 diabetes was analysed using time-dependent Cox models, adjusting for a number of covariates.

Results The unadjusted hazard ratio (HR) for the risk of type 2 diabetes for men was 1·13 (95 % CI 1·09, 1·17) and for women was 1·12 (95 % CI 1·08, 1·16) per additional 2-year increase in the duration of obesity. Adjustment for sociodemographic variables, family history of diabetes, health behaviour and physical activity made little difference to these HR. For women the evidence of a dose–response relationship was less clear than for men, particularly for women with an older age at obesity onset.

Conclusions The duration of obesity is a relevant risk factor for type 2 diabetes, independent of the degree of BMI.

Duration and persistence in multidimensional deprivation : methodology and Australian application

This article extends the recent literature on static multidimensional deprivation to propose dynamic deprivation measures that incorporate both the persistence and duration of deprivation across multiple dimensions. The article then illustrates the usefulness of the extension by applying it to Australian panel data for the recent period, 2001–2008. The empirical application exploits the subgroup decomposability of the deprivation measures to identify the subgroups that are more deprived than others. The proposed measure is also decomposable by dimensions and is used to identify the dimensions where deprivation is more persistent. The comparison between the subgroups shows that the divide between homeowners and non-homeowners is one of the sharpest, with the latter suffering much more deprivation than the former. The results are robust to alternative schemes for weighting and aggregating the dimensions as well as to the choice of model parameters.

Increased positive thought disorder with illness duration in patients with schizophrenia

It is unclear whether the severity of positive formal thought disorder, a core clinical feature of schizophrenia, is stable or worsening through the chronic course of the illness. The neurocognitive basis for positive thought disorder also remains unclear. The aim of the present paper was to examine the relationship between thought disorder as measured by the Thought Disorder Index (TDI) and duration of illness and neuropsychological indices in 79 patients with schizophrenia. TDI scores increased in proportion to illness duration. TDI scores were not associated with verbal memory or executive functioning. These results indicate an ongoing worsening of positive thought disorder through the course of illness in schizophrenia.

Novel watermarking methods for copyright protection of audio signals

This research presented improved watermarking methods for mono and stereo audio signals. To enhance the performance, novel methods are developed using echo hiding techniques and patchwork-based algorithms. The superior performances of the proposed methods are demonstrated by theoretical analysis and simulation examples, in comparison with the existing methods.