Learned ultra-wideband RADAR sensor model for augmented LIDAR-based traversability mapping in vegetated environments

In vegetated environments, reliable obstacle detection remains a challenge for state-of-the-art methods, which are usually based on geometrical representations of the environment built from LIDAR and/or visual data. In many cases, in practice field robots could safely traverse through vegetation, thereby avoiding costly detours. However, it is often mistakenly interpreted as an obstacle. Classifying vegetation is insufficient since there might be an obstacle hidden behind or within it. Some Ultra-wide band (UWB) radars can penetrate through vegetation to help distinguish actual obstacles from obstacle-free vegetation. However, these sensors provide noisy and low-accuracy data. Therefore, in this work we address the problem of reliable traversability estimation in vegetation by augmenting LIDAR-based traversability mapping with UWB radar data. A sensor model is learned from experimental data using a support vector machine to convert the radar data into occupancy probabilities. These are then fused with LIDAR-based traversability data. The resulting augmented traversability maps capture the fine resolution of LIDAR-based maps but clear safely traversable foliage from being interpreted as obstacle. We validate the approach experimentally using sensors mounted on two different mobile robots, navigating in two different environments.

Computer analysis of impact behavior of concrete filled steel tube columns

This paper presents a numerical study of the response of axially loaded concrete filled steel tube (CFST) columns under lateral impact loading using explicit non-linear finite element techniques. The aims of this paper are to evaluate the vulnerability of existing columns to credible impact events as well as to contribute new information towards the safe design of such vulnerable columns. The model incorporates concrete confinement, strain rate effects of steel and concrete, contact between the steel tube and concrete and dynamic relaxation for pre-loading, which is a relatively recent method for applying a pre-loading in the explicit solver. The finite element model was first verified by comparing results with existing experimental results and then employed to conduct a parametric sensitivity analysis. The effects of various structural and load parameters on the impact response of the CFST column were evaluated to identify the key controlling factors. Overall, the major parameters which influence the impact response of the column are the steel tube thickness to diameter ratio, the slenderness ratio and the impact velocity. The findings of this study will enhance the current state of knowledge in this area and can serve as a benchmark reference for future analysis and design of CFST columns under lateral impact.

Stone baby: An exploration of trembling and its potential for visual art

Informed by Kristeva's formulation of affect and Winnicott's Holding Environment, this practice-led visual art project is an exploration into how sensitivity to the physical sensation of trembling can sustain a creative practice. Building upon this is a further enquiry into what the significance of the affective experience of trembling is for an ethics of affect in contemporary art. I have done this through object and video-based installations informed by my own experience of trembling. This has been further informed by the work of artists like Louise Bourgeois, Dennis Del Favero and Willie Doherty. The creative outcomes contribute to the discourse around ethical responses to affect by extending and developing on the works of these artists.

The politics of art/Art of politics

Author Toni Morrison said, “All good art is political! There is none that isn’t”. Perhaps this is why the arts and artists throughout history have been positioned as dangerous, troubling and on the margin. Art works can ask questions of us, challenge assumptions and name the un-nameable. Art works challenge hegemonies and the status quo – they trouble politics. So what happens when arts meets politics when it comes to the entitlement for young Australians to an arts-rich education? How do we navigate the tricky waters of the political ebb and flow to champion the agenda for arts education in contemporary classrooms so that our young people can be cultural navigators, cultural auteurs and culture makers?

New microscale vertically oriented organic photovoltaics cells

We initially look at the changing energy environment and how that can have a dramatic change on the potential of alternative energies, in particular those of organic photovoltaicvs (OPV) cells. In looking at OPV's we also address the aspects of where we are with the current art and why we may not be getting the best from our materials. In doing so, we propose the idea of changing how we build organic photovoltaics by addressing the best method to contain light within the devices. Our initial effort is in addressing how these microscale optical concentrators work in the form of optical fibers in terms of absorption. We have derived a mathematical method which takes account of the input angle of light to achieve optimum absorption. However, in doing so we also address the complex issue how the changing refractive indices in a multilayer device can alter how we input the light. We have found that by knowing the materials refractive index our model takes into account the incident plane, meridonal plane, cross sectional are and path length to ensure optical angular input. Secondly, we also address the practicalities of making such vertical structures the greater issue of changing light intensity incident on a solar cell and how that aspects alters how we view the performance of organic solar cells.

A right of resale? Indigenous art under the hammer

This week, Sotheby's sold the late Clifford Possum Tjapaltjarri's painting, Warlugulong. The auction-house's spokesman, Tim Klingender, was enthusiastic about the high price commanded by the art work: "The painting was a really great painting and it deserved to make a really fantastic price, and it made that price."

Four stories about copyright law and appropriation art

This article considers copyright law and the art of appropriation in an Australian context. It tells four stories about Australian artists - Imants Tillers, Gordon Bennett, Juan Davila and Tracey Moffatt. The stories examine the postmodern critique of copyright law, indigenous copyright and self-determination, the introduction of moral rights, and copyright, photography and film. The article concludes that the work of such contemporary artists has practical implications for the reform of copyright law.

Improving deep convultional neural networks with unsupervised feature learning

The latest generation of Deep Convolutional Neural Networks (DCNN) have dramatically advanced challenging computer vision tasks, especially in object detection and object classification, achieving state-of-the-art performance in several computer vision tasks including text recognition, sign recognition, face recognition and scene understanding. The depth of these supervised networks has enabled learning deeper and hierarchical representation of features. In parallel, unsupervised deep learning such as Convolutional Deep Belief Network (CDBN) has also achieved state-of-the-art in many computer vision tasks. However, there is very limited research on jointly exploiting the strength of these two approaches. In this paper, we investigate the learning capability of both methods. We compare the output of individual layers and show that many learnt filters and outputs of the corresponding level layer are almost similar for both approaches. Stacking the DCNN on top of unsupervised layers or replacing layers in the DCNN with the corresponding learnt layers in the CDBN can improve the recognition/classification accuracy and training computational expense. We demonstrate the validity of the proposal on ImageNet dataset.

Ectopic calcification among families in the Azores: Clinical and radiologic manifestations in families with diffuse idiopathic skeletal hyperostosis and chondrocalcinosis

Objective. Twelve families that were multiply affected with diffuse idiopathic skeletal hyperostosis (DISH) and/or chondrocalcinosis, were identified on the island of Terceira, The Azores, potentially supporting the hypothesis that the 2 disorders share common etiopathogenic factors. The present study was undertaken to investigate this hypothesis. Methods. One hundred three individuals from 12 unrelated families were assessed. Probands were identified from patients attending the Rheumatic Diseases Clinic, Hospital de Santo Espirito, in The Azores. Family members were assessed by rheumatologists and radiologists. Radiographs of all family members were obtained, including radiographs of the dorsolumbar spine, pelvis, knees, elbows, and wrists, and all cases were screened for known features of chondrocalcinosis. Results. Ectopic calcifications were identified in 70 patients. The most frequent symptoms or findings were as follows: axial pain, elbow, knee and metacarpophalangeal (MCP) joint pain, swelling, and/or deformity, and radiographic enthesopathic changes. Elbow and MCP joint periarticular calcifications were observed in 35 and 5 patients, respectively, and chondrocalcinosis was identified in 12 patients. Fifteen patients had sacroiliac disease (ankylosis or sclerosis) on computed tomography scans. Fifty-two patients could be classified as having definite (17%), probable (26%), or possible (31%) DISH. Concomitant DISH and chondrocalcinosis was diagnosed in 12 patients. Pyrophosphate crystals were identified from knee effusions in 13 patients. The pattern of disease transmission was compatible with an autosomal-dominant monogenic disease. The mean age at which symptoms developed was 38 years. Conclusion. These families may represent a familial type of pyrophosphate arthropathy with a phenotype that includes peripheral and axial enthesopathic calcifications. The concurrence of DISH and chondrocalcinosis suggests a shared pathogenic mechanism in the 2 conditions.

Rehabilitation of individuals with bone-anchored prosthesis: State-of-the-art and challenges

Individuals with limb amputation fitted with conventional socket-suspended prostheses often experience socket-related discomfort leading to a significant decrease in quality of life. Bone-anchored prostheses are increasingly acknowledged as viable alternative method of attachment of artificial limb. In this case, the prosthesis is attached directly to the residual skeleton through a percutaneous fixation. To date, a few osseointegration fixations are commercially available. Several devices are at different stages of development particularly in Europe and the US.[1-15] Clearly, surgical procedures are currently blooming worldwide. Indeed, Australia and Queensland in particular have one of the fastest growing populations. Previous studies involving either screw-type implants or press-fit fixations for bone-anchorage have focused on fragmented biomechanics aspects as well as the clinical benefits and safety of the procedure. However, very few publications have synthetized this information and provided an overview of the current developments in bone-anchored prostheses worldwide, let alone in Australia. The purposes of the presentation will be: 1. To provide an overview of the state-of-art developments in bone-anchored prostheses with as strong emphasis on the design of fixations, treatment, benefits, risks as well as future opportunities and challenges, 2. To present the current international developments of procedures for bone-anchored prostheses in terms of numbers of centers, number of cases and typical case-mix, 3. To highlight the current role Australia is playing as a leader worldwide in terms of growing population, broadest range of case-mix, choices of fixations, development of reimbursement schemes, unique clinical outcome registry for evidence-based practice, cutting-edge research, consumer demand and general public interest.

Review and future options for computer modelling in the sugar industry

Computer modelling has been used extensively in some processes in the sugar industry to achieve significant gains. This paper reviews the investigations carried out over approximately the last twenty five years, including the successes but also areas where problems and delays have been encountered. In that time the capability of both hardware and software have increased dramatically. For some processes such as cane cleaning, cane billet preparation, and sugar drying, the application of computer modelling towards improved equipment design and operation has been quite limited. A particular problem has been the large number of particles and particle interactions in these…

Separable spatiotemporal priors for convex reconstruction of time-varying 3D point clouds

Reconstructing 3D motion data is highly under-constrained due to several common sources of data loss during measurement, such as projection, occlusion, or miscorrespondence. We present a statistical model of 3D motion data, based on the Kronecker structure of the spatiotemporal covariance of natural motion, as a prior on 3D motion. This prior is expressed as a matrix normal distribution, composed of separable and compact row and column covariances. We relate the marginals of the distribution to the shape, trajectory, and shape-trajectory models of prior art. When the marginal shape distribution is not available from training data, we show how placing a hierarchical prior over shapes results in a convex MAP solution in terms of the trace-norm. The matrix normal distribution, fit to a single sequence, outperforms state-of-the-art methods at reconstructing 3D motion data in the presence of significant data loss, while providing covariance estimates of the imputed points.

Surface materials and aspects of care: A study in modes of being in a visual art practice

Through creative practice and written research, this thesis explores the peculiar qualities of surface materials, revealing a broader ethos of practice which I identify as care. I propose that care arises as a mode of being between artist and work, work and beholder, and between the parts of the work. The thesis situates the art practice within an ethical framework, premised on, but extending, Heidegger's ontological equation of care with being. The original contribution is in the claim that the particular qualities of worldly matter generate the terms for care as a particular mode of engagement that is reciprocal and intransitive.

Cosmopolitan tendencies in recent intersubjective art

This thesis uses cultural studies approaches to ask in what ways can intersubjective art act on the disparities brought about by late capitalism through the auspices of cosmopolitanism? How do the same processes that oppress others allow the artist to be mobile and self-reflexive while accruing and deploying a broad range of knowledges and competencies? The answer is paradoxical: those oppressed by the processes of late capitalism become the focus, theme, and content of the intersubjective artwork while the artists benefit from a system they seek to problematise and critique. Three case study chapters highlight these complex and disconcerting politics.

Art museums and the global tourist: Experience centers in experiencescapes

Art museums are playing an important role is attracting cultural tourists to global cities and regions. Traditionally, art museums were primarily known for their didactic role. In a post-avant-garde era however museums are more focused on appealing to a broader clientele that want art to be novel and entertaining. Art museums have also come to play a greater role in gentrification projects and cultural precincts. This is because they are ideally suited for tourist-centric environments that offer a variety of immersive sensory experiences, and combine museums (often designed by star-architects), international hotels, restaurants, high-end shopping zones, and other leisure platforms. These "experiencescapes" include Port Maravilha urban waterfront development in Rio de Janiero, the Shanghai Bund, and the Broad project in Los Angeles. The Museum of Old and New Art in Hobart Australia is a boutique player in the global market for experiencescapes. It is smaller than many of its competitors and is situated in a remote part of the world, yet it has made an important contribution to Tasmania’s tourism industry.