Mapping indicators of riparian vegetation health using IKONOS and Landsat-7 ETM+ image data in Australian tropical savannas

Government agencies responsible for riparian environments are assessing the utility of remote sensing for mapping and monitoring environmental health indicators. The objective of this work was to evaluate IKONOS and Landsat-7 ETM+ imagery for mapping riparian vegetation health indicators in tropical savannas for a section of Keelbottom Creek, Queensland, Australia. Vegetation indices and image texture from IKONOS data were used for estimating percentage canopy cover (r2=0.86). Pan-sharpened IKONOS data were used to map riparian species composition (overall accuracy=55%) and riparian zone width (accuracy within 4 m). Tree crowns could not be automatically delineated due to the lack of contrast between canopies and adjacent grass cover. The ETM+ imagery was suited for mapping the extent of riparian zones. Results presented demonstrate the capabilities of high and moderate spatial resolution imagery for mapping properties of riparian zones, which may be used as riparian environmental health indicators

Methods for Categorical Longitudinal Survey Data: Understanding Employment Status of Australian Women

Many variables that are of interest in social science research are nominal variables with two or more categories, such as employment status, occupation, political preference, or self-reported health status. With longitudinal survey data it is possible to analyse the transitions of individuals between different employment states or occupations (for example). In the statistical literature, models for analysing categorical dependent variables with repeated observations belong to the family of models known as generalized linear mixed models (GLMMs). The specific GLMM for a dependent variable with three or more categories is the multinomial logit random effects model. For these models, the marginal distribution of the response does not have a closed form solution and hence numerical integration must be used to obtain maximum likelihood estimates for the model parameters. Techniques for implementing the numerical integration are available but are computationally intensive requiring a large amount of computer processing time that increases with the number of clusters (or individuals) in the data and are not always readily accessible to the practitioner in standard software. For the purposes of analysing categorical response data from a longitudinal social survey, there is clearly a need to evaluate the existing procedures for estimating multinomial logit random effects model in terms of accuracy, efficiency and computing time. The computational time will have significant implications as to the preferred approach by researchers. In this paper we evaluate statistical software procedures that utilise adaptive Gaussian quadrature and MCMC methods, with specific application to modeling employment status of women using a GLMM, over three waves of the HILDA survey.

Parental influences on preschoolers’ TV viewing time: mediation analyses on Australian and Belgian data

Television viewing is highly prevalent in preschoolers (3–5 years). Because of the adverse health outcomes related to this behavior, it is important to investigate associations and mediators of young children’s television viewing time. This study investigated whether parental rules regarding television viewing time and parental concerns about screen viewing activities mediated the association between parents’ and preschoolers’ television viewing time. Methods: Mediation analyses were performed with the product-of-coefficient test on data derived from the Australian HAPPY study (n = 947) and the Belgian sample of the ToyBox-study (n = 1527). Parents reported their own and their child’s television viewing time, their rules regarding television viewing and concerns about their child’s screen viewing activities. Results: Parents’ television viewing time was directly associated with preschoolers’ television viewing time and parental rule for television viewing time mediated this association in both samples (14.4% and 8.1% in the Australian and Belgian samples, respectively). Conclusions: This study is unique in examining the mediating pathway of parental television viewing and a rule limiting TV viewing time and whether this is consistent in different samples. Due to the consistent importance, both parents’ television viewing time and rules should be targeted in interventions to decrease preschoolers’ television viewing time.

Managing undesirable outputs in the Australian construction industry using Data Envelopment Analysis models

Carbon reduction has become one of the most significant challenges for economic growth. This paper presents the preliminary analysis of undesirable output reduction targets and emission schedules in temporal-spatial comparisons based on Data Envelopment Analysis. The reduction targets of undesirable outputs are investigated, including the maximum, input, technical and ideal reduction targets. Four Data Envelopment Analysis models that are based on a sequential benchmark technology and variable returns to scale are introduced to measure these reduction percentages. In order to formulate the optimal emission schedule of undesirable outputs, an optimal model is provided without inflation. Data from the Australian construction industry from 2000 to 2010 are employed to develop the models. The results of the analysis indicate that the Australian Government could achieve its promised carbon reduction targets in the construction industry. Most Australian regions' construction industries possess carbon mitigation potential and some of them could increase their desirable outputs if carbon were decreased. This paper suggests that policymakers can benefit from formulating various suitable undesirable output reduction objectives and schedules through the models developed. The research method can be replicated for other sectors and regions focussing on undesirable output reduction.

Television viewing time and 13-year mortality in adults with cardiovascular disease: data from the Australian Diabetes, Obesity and Lifestyle Study (AusDiab)

BACKGROUND: In the general population, excessive sedentary behaviour is associated with increased all-cause mortality. Few studies have examined this relationship in people with cardiovascular disease (CVD). Using a sample of people with CVD who were excluded from an analysis of the Australian Diabetes, Obesity and Lifestyle (AusDiab) study, we examined the relationship between sedentary behaviour and 13-year all-cause mortality.

METHODS: In the original AusDiab study, television viewing time was used as a marker of sedentary behaviour in 609 adults (≥45 years of age) with CVD. During 6,291 person-years of follow-up (median follow-up 13 years), there were 294 deaths (48% of sample). Using the time scale of attained age, the Cox proportional hazards model predicting all-cause mortality adjusted for sex, self-rated general health, leisure-time physical activity, smoking status, education, household income, body mass index, lipid levels, blood pressure, and diabetes mellitus was used.

RESULTS: Compared with a TV viewing time of <2hours per day, the fully adjusted hazard ratios for all-cause mortality were 1.18 (95% CI, 0.88 to 1.57) for ≥2 to <4hours per day and 1.52 (95% CI, 1.09 to 2.13) for >4hours per day.

CONCLUSIONS: Sedentary behaviour was associated with increased risk of all-cause mortality in people with CVD, independent of physical activity and other confounders. In addition to the promotion of regular physical activity, cardiac rehabilitation efforts which also focus on reducing sedentary behaviour may be beneficial.

Characterising the Australian engineering workforce and engineering graduate occupational outcomes using national census data

The purpose of undergraduate engineering education is to develop graduates who are capable of commencing professional engineering practice. Professional education should equip graduates with the skills, knowledge and attitudes required for their initial professional practice. It should also enable the capacity to continue the professional development required to refresh knowledge and skills as the graduates mature and the nature of professional engineering work develops. However, it is true that many graduates from professional engineering programs, either immediately or at some later time, pursue a career outside of professional engineering. The reasons for this are widely speculated upon, and are no doubt complex. In this regard, the professional engineering workforce, the undergraduate engineering education system, the links between them, and the occupational outcomes for engineering graduates in Australia are similar to many other developed nations. Using the latest Australian national census data we present a detailed analysis of the makeup of the professional engineering workforce and the occupational outcomes for graduates of undergraduate engineering programs in Australia. The data show that the Australian professional engineering workforce is comprised of people with a wide range of educational qualifications, and, even immediately post-graduation, many Australian engineering graduates pursue non-engineering occupations. This analysis presents important findings for those designing undergraduate engineering curricula that seek to equip students for the best employment outcomes, given the nature of the professional engineering work environment, and the short- and long-term occupations that engineering graduates actually pursue in Australia.

The Australian Parliament: A Gendered Organisation

Limited work has been undertaken on the subject of gender and Australian parliamentary institutions. This study of 13 male and 15 female members of the Australian parliament addresses this gap in the literature. Data from the study are used to explore the ways in which the institutions of political office operate as ‘gendered organisations’ (Acker 1990). What emerges from this analysis is the pervasiveness of gender across the processes, practices and discourses of the parliament. This is a space infused with hegemonic masculinity. This gendering is, however, normalised and/or minimised by many of the parliamentarians involved in the study.

Property cash flow studies : focusing on model consistency and data accuracy

The high degree of variability and inconsistency in cash flow study usage by property professionals demands improvement in knowledge and processes. Until recently limited research was being undertaken on the use of cash flow studies in property valuations but the growing acceptance of this approach for major investment valuations has resulted in renewed interest in this topic. Studies on valuation variations identify data accuracy, model consistency and bias as major concerns. In cash flow studies there are practical problems with the input data and the consistency of the models. This study will refer to the recent literature and identify the major factors in model inconsistency and data selection. A detailed case study will be used to examine the effects of changes in structure and inputs. The key variable inputs will be identified and proposals developed to improve the selection process for these key variables. The variables will be selected with the aid of sensitivity studies and alternative ways of quantifying the key variables explained. The paper recommends, with reservations, the use of probability profiles of the variables and the incorporation of this data in simulation exercises. The use of Monte Carlo simulation is demonstrated and the factors influencing the structure of the probability distributions of the key variables are outline. This study relates to ongoing research into functional performance of commercial property within an Australian Cooperative Research Centre.

Fan motivation and loyalty : extending the Sport Interest Inventory (SII) to the Australian Football League

This study used the Sport Interest Inventory (SII) to examine the motivation of fans attending a game in the Australian Football League. This is the first study to use the SII for professional men’s team sport outside the United States. Confirmatory factor analysis showed the model provided a good fit for the data collected in Australia, and regression analysis revealed that team interest, vicarious achievement, excitement and player interest were the significant factors in predicting and explaining the level of attitudinal loyalty of fans toward their favourite team.

Australian Indigenous students: addressing equity issues in assessment

This article provides the background and context to the important issue of assessment and equity in relation to Indigenous students in Australia. Questions about the validity and fairness of assessment are raised and ways forward are suggested by attending to assessment questions in relation to equity and culture-fair assessment. Patterns of under-achievement by Indigenous students are reflected in national benchmark data and international testing programmes like the Trends in International Mathematics and Science Sstudy and the Program for International Student Assessment. The argument developed views equity, in relation to assessment, as more of a sociocultural issue than a technical matter. It highlights how teachers need to distinguish the "funds of knowledge" that Indigenous students draw on and how teachers need to adopt culturally responsive pedagogy to open up the curriculum and assessment practice to allow for different ways of knowing and being.