A method to quantify a descriptor's illumination variance

This paper presents a new metric, which we call the lighting variance ratio, for quantifying descriptors in terms of their variance to illumination changes. In many applications it is desirable to have descriptors that are robust to changes in illumination, especially in outdoor environments. The lighting variance ratio is useful for comparing descriptors and determining if a descriptor is lighting invariant enough for a given environment. The metric is analysed across a number of datasets, cameras and descriptors. The results show that the upright SIFT descriptor is typically the most lighting invariant descriptor.

A lightweight, modular robotic vehicle for the sustainable intensification of agriculture

This paper describes a lightweight, modular and energy efficient robotic vehicle platform designed for broadacre agriculture - the Small Robotic Farm Vehicle (SRFV). The current trend in farming is towards increasingly large machines that optimise the individual farmer’s productivity. Instead, the SRFV is designed to promote the sustainable intensification of agriculture by allowing farmers to concentrate on more important farm management tasks. The robot has been designed with a user-centred approach which focuses the outcomes of the project on the needs of the key project stakeholders. In this way user and environmental considerations for broadacre farming have informed the vehicle platform configuration, locomotion, power requirements and chassis construction. The resultant design is a lightweight, modular four-wheeled differential steer vehicle incorporating custom twin in-hub electric drives with emergency brakes. The vehicle is designed for a balance between low soil impact, stability, energy efficiency and traction. The paper includes modelling of the robot’s dynamics during an emergency brake in order to determine the potential for tipping. The vehicle is powered by a selection of energy sources including rechargeable lithium batteries and petrol-electric generators.

Tracking control of a class of Hamiltonian mechanical systems with disturbances

This paper presents a trajectory-tracking control strategy for a class of mechanical systems in Hamiltonian form. The class is characterised by a simplectic interconnection arising from the use of generalised coordinates and full actuation. The tracking error dynamic is modelled as a port-Hamiltonian Systems (PHS). The control action is designed to take the error dynamics into a desired closed-loop PHS characterised by a constant mass matrix and a potential energy with a minimum at the origin. A transformation of the momentum and a feedback control is exploited to obtain a constant generalised mass matrix in closed loop. The stability of the close-loop system is shown using the close-loop Hamiltonian as a Lyapunov function. The paper also considers the addition of integral action to design a robust controller that ensures tracking in spite of disturbances. As a case study, the proposed control design methodology is applied to a fully actuated robotic manipulator.

John Andrews : Architecture a Performing Art

The distinguished Australian architect surveys his career and examines how his architectural theories are expressed in his designs.

Matter and movement: Expression as topological continuity or a return to Butades' wall

This paper aims to address the ways in which drawing can be understood as the becoming-expressive of materials, site, and body, over time. The discussion pivots around a series of studies that replace linear or causal relationships – in history, drawing and expression – with topological movement. My approach is largely through a speculative case study. In a rereading of the familiar Butades myth, I examine how a shadow tracing can variously be taken as the first mimetic art with its origins in the urge to “capture”, and, antithetically, as the originary expressive folding of matter, site and body. The paper is divided into five sections. The first presents the Butades myth, identifying the representational problem that lies at the roots of its traditional telling. The next three sections outline a series of topologies that facilitate a discussion of the Butades myth from historical, disciplinary, and expressive perspectives. The final section aims to show the relevance of this discussion to a contemporary drawing practice, using my own drawing research as a case study. The field of inquiry is that of representational critique. The fold, an image associated with a topological geometry, replaces the relational or signifying disjuncture of representational structures, and suggests a becoming- expressive of subject and object, form and matter.

Lecturing for non-law background students: Assessing the cognitive load of case and legislation-based lecturing approaches

Lecturing is a traditional method for teaching in discipline-based teaching environments and its success in legal discipline depends upon its alignment with learner backgrounds, learning objectives and the lecturing approaches utilised in the classes. In a situation where students do not have any prior knowledge of the given discipline that requires a particular lecturing approach, a mismatch in such an alignment would place learner knowledge acquisition into a challenging situation. From this perspective, this study tests the suitability of two dominant lecturing approaches—the case and the law-based lecturing approaches. It finds that a lecturer should put more emphasis on the case-based approach while lecturing to non-law background business students at the postgraduate level, provided that such an emphasis should be relative to the cognitive ability of the students and their motivation for learning law units.

System design for a small autonomous helicopter

The detailed system design of a small experimental autonomous helicopter is described. The system requires no ground-to-helicopter communications and hence all automation hardware is on-board the helicopter. All elements of the system are described including the control computer, the flight computer (the helicopter-to-control-computer interface), the sensors and the software. A number of critical implementation issues are also discussed.

Height estimation for an autonomous helicopter

Height is a critical variable for helicopter hover control. In this paper we discuss, and present experimental results for, two different height sensing techniques: ultrasonic and stereo imaging, which have complementary characteristics. Feature-based stereo is used which provides a basis for visual odometry and attitude estimation in the future.

Securing Australia's future: The role of science, research and technology in lifting Australian productivity

A three-year research program funded by the Australian Research Council and conducted by the four Learned Academies through the Australian Council of Learned Academies for PMSEIC, through the Office of the Chief Scientist. Securing Australia’s Future delivers research-based evidence and findings to support policy development in areas of importance to Australia’s future.

Predicting emotional exhaustion among haemodialysis nurses

Background Understanding the organisational predictors of burnout (emotional exhaustion) in haemodialysis nurses is critical for staff retention and improving nurse and patient outcomes. Previous research has demonstrated high levels of emotional exhaustion among haemodialysis nurses; yet the relationships among nurses’ work environment, job satisfaction, stress and emotional exhaustion are poorly understood. Aim To test an explanatory model of the relationships among the nursing work environment, job satisfaction, job stress and emotional exhaustion for haemodialysis nurses, drawing on Kanter’s Structural Theory of Organisational Empowerment. Methods Using a cross-sectional design 417 haemodialysis nurses completed an online survey between October 2011 and April 2012 using validated instruments to measure the work environment, and levels of job satisfaction, job stress and emotional exhaustion. Results Overall, the explanatory model demonstrated adequate fit and we found partial support for the hypothesised relationships. Haemodialysis nurses’ work environment had a direct positive effect on job satisfaction, explaining 88% of the variance. Greater job satisfaction, in turn, predicted lower job stress, explaining 82% of the variance. Job satisfaction also had an indirect effect on emotional exhaustion by mitigating job stress. However, job satisfaction did not have a direct effect on emotional exhaustion. Conclusion The work environment of haemodialysis nurses is pivotal to the development of job satisfaction. Nurses’ job satisfaction also affects the levels of job stress and emotional exhaustion. Our findings suggest nurse managers can improve staff retention by creating empowering work environments that promote job satisfaction in haemodialysis nurses.

Why are haemodialysis nurses satisfied also experiencing burnout?

Background Haemodialysis nurses work in a technological environment caring for patients over a prolonged period of time leading to the development of unique nurse-patient relationships. In order to improve retention of nurses in this specialised area of nursing it is important to know the factors that affect job satisfaction, stress and burnout and understand how these experiences are conceptualised by haemodialysis nurses. Aim To explore the factors contributing to satisfaction with the work environment, job satisfaction, job stress and burnout in haemodialysis nurses in Australia and New Zealand. Method A quantitative dominant sequential explanatory mixed method design was used. Quantitative data was collected using an on-line questionnaire containing demographic questions and pre-existing instruments examining job satisfaction, stress, burnout and satisfaction with the work environment. The qualitative phase involved semi-structured interviews. Results 417 nurses completed the questionnaire. Overall, nurses were satisfied with their work environment and the job that they performed but there were stressors in the haemodialysis setting that led to high levels of burnout. Key themes emerged from the qualitative data related to the physical environment, intensity of nurse-patient relationships, workloads, and coping with death and dying. The qualitative findings also provide possible explanations for the high level of burnout identified in the quantitative findings. Conclusion Explanation of areas where specific nurse and patient outcomes were affected will support the development of appropriate interventions to sustain a work environment conducive to job satisfaction that also alleviates stress and burnout in these nurses.

Being here: Designing for distributed hands-on collaboration in blended interaction spaces

This paper describes a concept for supporting distributed hands-on collaboration through interaction design for the physical and the digital workspace. The Blended Interaction Spaces concept creates distributed work environments in which collaborating parties all feel that they are present “here” rather than “there”. We describe thinking and inspirations behind the Blended Interaction Spaces concept, and summarize findings from fieldwork activities informing our design. We then exemplify the Blended Interaction Spaces concept through a prototype implementation of one of four concepts.

Orchids: Gardening creative practice on screen

Orchids: Gardening creative practice on screen explores the creative practice challenges of working with bodies with intersex in the long-form autobiographical film Orchids: My Intersex Adventure. Just as creative practice research challenges the dominant hegemony of quantitative and qualitative research, so does my creative work position itself as a nuanced piece, pushing the boundaries of traditional cultural studies theories, documentary film practice and creative practice method, through its distinctive distillation and celebration of a new form of discursive rupturing, the intersex voice.