Fuzzy System Dynamics Risk Analysis (FuSDRA) of Autonomous Underwater Vehicle Operations in the Antarctic

With the maturing of autonomous technology and better accessibility, there has been a growing interest in the use of autonomous underwater vehicles (AUVs). The deployment of AUVs for under-ice marine science research in the Antarctic is one such example. However, a higher risk of AUV loss is present during such endeavors due to the extreme operating environment. To control the risk of loss, existing risk analyses approaches tend to focus more on the AUV's technical aspects and neglect the role of soft factors, such as organizational and human influences. In addition, the dynamic and complex interrelationships of risk variables are also often overlooked due to uncertainties and challenges in quantification. To overcome these shortfalls, a hybrid fuzzy system dynamics risk analysis (FuSDRA) is proposed. In the FuSDRA framework, system dynamics models the interrelationships between risk variables from different dimensions and considers the time-dependent nature of risk while fuzzy logic accounts for uncertainties. To demonstrate its application, an example based on an actual Antarctic AUV program is presented. Focusing on funding and experience of the AUV team, simulation of the FuSDRA risk model shows a declining risk of loss from 0.293 in the early years of the Antarctic AUV program, reaching a minimum of 0.206 before increasing again in later years. Risk control policy recommendations were then derived from the analysis. The example demonstrated how FuSDRA can be applied to inform funding and risk management strategies, or broader application both within the AUV domain and on other complex technological systems.     

Productive engagement across the life course: paid work and beyond

An uncertain economic outlook and the certitude of an ageing population highlight the importance of productive activity across all age groups for Australia's future. This paper reviews Australian and international research on productive ageing, which has typically focused on older age groups and specific activities, and presents national findings from Wave 10 (2010) of the Household, Income and Labour Dynamics in Australia (HILDA) Survey on productive activities across the life course. Both paid, tax‐generating and unpaid, voluntary activities are examined, including paid work, volunteering, caregiving, childcare, and domestic work. The kinds of productive activity people engaged in varied across age groups for men and women, highlighting the potential competition between paid work and other activities, and the importance of health and education for engagement across all ages. While the Government has begun leading actions to enhance and recognise these contributions that bring economic and social benefits both to the individual and the broader community, our research reinforces the value of investment in human capital for productive engagement across the lifespan inclusive of early, middle and later life.     

Deconstructing the silences: gay social memory

Adopting a Foucaultian perceptive, this article deconstructs the silences in the Singaporean gay community. The collective absences in homosexuals' social memory is not simply reflective of a fragmented community, but must be comprehended in relation to the role of the state and media in shaping particular discourses.     

Intake Fraction Variability Between Air Pollution Emission Sources Inside an Urban Area

The cost‐effective mitigation of adverse health effects caused by air pollution requires information on the contribution of different emission sources to exposure. In urban areas the exposure potential of different sources may vary significantly depending on emission height, population density, and other factors. In this study, we quantified this intraurban variability by predicting intake fraction (iF) for 3,066 emission sources in Warsaw, Poland. iF describes the fraction of the pollutant that is inhaled by people in the study area. We considered the following seven pollutants: particulate matter (PM), nitrogen oxides (NO_x), sulfur dioxide (SO₂), benzo[a] pyrene (BaP), nickel (Ni), cadmium (Cd), and lead (Pb). Emissions for these pollutants were grouped into four emission source categories (Mobile, Area, High Point, and Other Point sources). The dispersion of the pollutants was predicted with the CALPUFF dispersion model using the year 2005 emission rate data and meteorological records. The resulting annual average concentrations were combined with population data to predict the contribution of each individual source to population exposure. The iFs for different pollutant‐source category combinations varied between 51 per million (PM from Mobile sources) and 0.013 per million (sulfate PM from High Point sources). The intraurban iF variability for Mobile sources primary PM emission was from 4 per million to 100 per million with the emission‐weighted iF of 44 per million. These results propose that exposure due to intraurban air pollution emissions could be decreased more effectively by specifically targeting sources with high exposure potency rather than all sources.     

A note on the geometry of kullback-leibler information numbers

Csiszar (1975) has shown thdt kullhack-Leibler information numbers possess some geometrical properties much like those in Euclidean geometry. Thls paper extends these results by characterizing the shortest line between two ditributions as well as the midpoit of the line.     

Uniform robustness against nonnormality of the t and f tests

The size of the two-sample t test is generally thought to be robust against nonnormal distributions if the sample sizes are large. This belief is based on central limit theory, and asymptotic expansions of the moments of the t statistic suggest that robustness may be improved for moderate sample sizes if the variance, skewness, and kurtosis of the distributions are matched, particularly if the sample sizes are also equal.

It is shown that asymptotic arguments such as these can be misleading and that, in fact, the size of the t test can be as large as unity if the distributions are allowed to be completely arbitrary. Restricting the distributions to be identical or symmetric (but otherwise arbitrary) does not guarantee that the size can be controlled either, but controlling the tail-heaviness of the distributions does. The last result is proved more generally for the k-sample F test.     

Partially-adaptive robust estimators of location via exponential embedding

A general method is presented for constructing a location estimator which is asymptotically efficient at any two different location-scale families of symmetric distributions as well as at an appropriately defined class of distributions lying in between. The method works by embedding the two families in a comprehensive parametric model and identifying the estimator with the MLE. The case when the families are Normal and Double exponential is examined in detail.     

Multiple Dimensions of Cigarette Smoking and Responsiveness to Cigarette Price Changes in Taiwan

This study investigates how smokers respond to both short- and long-run changes in the price of cigarettes in multiple dimensions of smoking behavior. Using a sample of males from a national longitudinal survey in Taiwan, we estimated the demand for cigarettes under both short- and long-run specifications using a quality-purged price index. We found a modest short-run price elasticity of demand for cigarettes and a long-run elasticity of demand that did not significantly exceed the short-run elasticity. We also found that smokers responded to higher cigarette prices by smoking each cigarette more fully without changing their choices of tar and nicotine content to compensate for reduced cigarette consumption.

Should Parents Financially Support their Adult Children? Normative Views in Australia

Social welfare policies generally assume that parents remain responsible for adult children. Recent social changes in industrialized nations, however, have rendered family obligation norms more complex. We examined 300 Australians’ norms concerning parents’ obligations to support adult children financially. Utilizing a quasi-experimental design, we investigated the extent to which respondents agreed that parents should support adult children, and the influence of situational factors. More respondents were in favor of assisting adult children than against, but there was no consensus as to what parents should do. Respondents generally agreed on factors that should be considered, then attempted to balance parental responsibility norms with adult independence norms. Parental help was more strongly endorsed when need was considered legitimate, and when the adult child was younger. Implications for Australian social policy are discussed.