Image-based safety assessment : automated spatial safety risk identification of earthmoving and surface mining activities

This paper presents an automated image‐based safety assessment method for earthmoving and surface mining activities. The literature review revealed the possible causes of accidents on earthmoving operations, investigated the spatial risk factors of these types of accident, and identified spatial data needs for automated safety assessment based on current safety regulations. Image‐based data collection devices and algorithms for safety assessment were then evaluated. Analysis methods and rules for monitoring safety violations were also discussed. The experimental results showed that the safety assessment method collected spatial data using stereo vision cameras, applied object identification and tracking algorithms, and finally utilized identified and tracked object information for safety decision making.

The last post? Tracking the Australasian to Aussie Post, 1864-2002

Aussie Post, the flagship of ocker Australiana, folded in January 2002. Post began life as the Australasian, a middlebrow magazine steeped in a nineteenth century civics of stable citizenship with a modicum of diversionary leisure. The transformation began when the Australasian became Australasian Post in 1946 under George Johnston's brief 15-week editorship. Johnston's idealistic vision of Post as a voice of post-war Australian modernity was soon overtaken by commercial imperatives as Post's identity wavered between its civic antecedents and a new low-brow populism, a niche it had finally settled into by the mid-1950s. This tension between staid civics and risqué populism shaped the magazine's long evolution into its final realisation of the pictorial general interest genre. This paper, based on a close examination of the magazines themselves, tracks Post's generic evolution and focuses on the struggle to redefine the magazine’s identity during the post-war period when the axis of Australian identity was reluctantly shifting from the staid traditions of Rule Britannia to the flashy modernity of Pax Americana.

Path planning, guidance and control for a UAV forced landing

A forced landing is an unscheduled event in flight requiring an emergency landing, and is most commonly attributed to engine failure, failure of avionics or adverse weather. Since the ability to conduct a successful forced landing is the primary indicator for safety in the aviation industry, automating this capability for unmanned aerial vehicles (UAVs) will help facilitate their integration into, and subsequent routine operations over civilian airspace. Currently, there is no commercial system available to perform this task; however, a team at the Australian Research Centre for Aerospace Automation (ARCAA) is working towards developing such an automated forced landing system. This system, codenamed Flight Guardian, will operate onboard the aircraft and use machine vision for site identification, artificial intelligence for data assessment and evaluation, and path planning, guidance and control techniques to actualize the landing. This thesis focuses on research specific to the third category, and presents the design, testing and evaluation of a Trajectory Generation and Guidance System (TGGS) that navigates the aircraft to land at a chosen site, following an engine failure. Firstly, two algorithms are developed that adapts manned aircraft forced landing techniques to suit the UAV planning problem. Algorithm 1 allows the UAV to select a route (from a library) based on a fixed glide range and the ambient wind conditions, while Algorithm 2 uses a series of adjustable waypoints to cater for changing winds. A comparison of both algorithms in over 200 simulated forced landings found that using Algorithm 2, twice as many landings were within the designated area, with an average lateral miss distance of 200 m at the aimpoint. These results present a baseline for further refinements to the planning algorithms. A significant contribution is seen in the design of the 3-D Dubins Curves planning algorithm, which extends the elementary concepts underlying 2-D Dubins paths to account for powerless flight in three dimensions. This has also resulted in the development of new methods in testing for path traversability, in losing excess altitude, and in the actual path formation to ensure aircraft stability. Simulations using this algorithm have demonstrated lateral and vertical miss distances of under 20 m at the approach point, in wind speeds of up to 9 m/s. This is greater than a tenfold improvement on Algorithm 2 and emulates the performance of manned, powered aircraft. The lateral guidance algorithm originally developed by Park, Deyst, and How (2007) is enhanced to include wind information in the guidance logic. A simple assumption is also made that reduces the complexity of the algorithm in following a circular path, yet without sacrificing performance. Finally, a specific method of supplying the correct turning direction is also used. Simulations have shown that this new algorithm, named the Enhanced Nonlinear Guidance (ENG) algorithm, performs much better in changing winds, with cross-track errors at the approach point within 2 m, compared to over 10 m using Park's algorithm. A fourth contribution is made in designing the Flight Path Following Guidance (FPFG) algorithm, which uses path angle calculations and the MacCready theory to determine the optimal speed to fly in winds. This algorithm also uses proportional integral- derivative (PID) gain schedules to finely tune the tracking accuracies, and has demonstrated in simulation vertical miss distances of under 2 m in changing winds. A fifth contribution is made in designing the Modified Proportional Navigation (MPN) algorithm, which uses principles from proportional navigation and the ENG algorithm, as well as methods specifically its own, to calculate the required pitch to fly. This algorithm is robust to wind changes, and is easily adaptable to any aircraft type. Tracking accuracies obtained with this algorithm are also comparable to those obtained using the FPFG algorithm. For all three preceding guidance algorithms, a novel method utilising the geometric and time relationship between aircraft and path is also employed to ensure that the aircraft is still able to track the desired path to completion in strong winds, while remaining stabilised. Finally, a derived contribution is made in modifying the 3-D Dubins Curves algorithm to suit helicopter flight dynamics. This modification allows a helicopter to autonomously track both stationary and moving targets in flight, and is highly advantageous for applications such as traffic surveillance, police pursuit, security or payload delivery. Each of these achievements serves to enhance the on-board autonomy and safety of a UAV, which in turn will help facilitate the integration of UAVs into civilian airspace for a wider appreciation of the good that they can provide. The automated UAV forced landing planning and guidance strategies presented in this thesis will allow the progression of this technology from the design and developmental stages, through to a prototype system that can demonstrate its effectiveness to the UAV research and operations community.

Parent decisions regarding paid work and care of the child

Australia has witnessed a continual increase in maternal employment over the past two decades, which has placed focus on child care- its effects on the child and on early childhood education and care policy and provision. The engagement of women in the paid workforce contributes to national economic development, and is recognised in government policy incentives such as cash subsidies and tax relief for child care fees. These incentives are targeted towards mothers, to encourage them to engage in paid work. Making a contribution to the family’s economy and to a mother’s economic self sufficiency are two key drivers for women’s engagement in satisfying paid work. Many women also seek to maintain a personal investment in the development of their career, simultaneously ensuring that the child is experiencing suitable care. Policies that support women’s choices for satisfying workforce engagement and care arrangements are prudent for ensuring productivity of the economy as well as for enhancing the wellbeing of parents and children (OECD, 2007). Policies that provide family friendly employment arrangements, paid parental leave, and child care support, directly affect maternal employment decisions. Availability of family friendly employment policies is viewed as one way to not only promote gender equity in employment opportunities but also support the wellbeing of children and families (OECD, 2007). Yet there are not comprehensive and coherent policies on work and family in Australia. Australia is due to implement its first paid parental leave scheme in January, 2011. At the time of the data collection of this research, June 2007 to December 2008, Australia had no statutory provision for paid parental leave. To date, most research has focused on the consequences of paid work and care decisions made by women. Far less is known about the processes of decision-making and reasons underlying women’s choices. Investigation of what is most salient for women as they make decisions regarding engagement in paid work, and care for their child is important in order to inform policy and practices related to parental leave, family friendly employment and care for the child. This prospective longitudinal research was of 124 Australian expectant first-time mothers who completed questionnaires in their third trimester of pregnancy, and again at six and twelve months postpartum. First-time expectant mothers' decisions regarding engaging in paid work and selecting care for their child represent those of a group who are invested in motherhood and have usually had direct experience of engaging in paid work. They therefore provide an important insight into society’s idealised views about motherhood and the emotional and social uncertainty of making personal decisions where the consequences of such decisions are unknown. These decisions reflect public beliefs about the role of women in contributing to the country’s productivity and decisions about providing for the economic and emotional care needs of their family. As so little is known about the reasoning and processes of decision-making of women’s choices regarding paid work and care of the child this research was designed to capture expectant first-time mother’s preferred options for engaging in paid work and the care of their child, and investigate their actual decisions made at six and 12 months postpartum. To capture preferred options, decisions and outcomes of decisions regarding paid work and care of the child a prospective longitudinal research design was utilised. This design had three important components that addressed key limitations in the extant literature. First the research commenced in pregnancy in order to investigate preferences and beliefs about paid work and care and to examine baseline data that may influence decisions made as the women returned to paid work. Second the research involved longitudinal tracking from the antenatal time point to six and 12 months postpartum in order to identify the influences on decisions made. Third the research measured outcomes of the decisions made at each time point. This research examined the intentions, preferences, beliefs, influences, and outcomes of the decisions about engagement in paid work and choice of care. The analyses examined factors predicting return to paid work, the timing of return and extent of engagement in paid work; the care for the child; satisfaction with paid work; satisfaction with care for the child, motherhood and fulfilment; and maternal wellbeing at six and 12 months postpartum. The factors of interest were both rational/economic (availability and extent of paid and unpaid maternity leave; flexible work patterns) and emotional/affective (career satisfaction, investment in motherhood, and concern with quality of care for the child). Results indicated a group preference, and realisation for, return to paid work within the first year after the birth of a child but with reduction in hours to part-time. Most women saw paid work not only as a source of income but also as source of personal satisfaction. There were four key themes arising from this research. First, the women strived to feel emotionally secure when deciding about engaging in paid work and care of the child. To achieve emotional security women made their decisions for paid work and care of the child differently. A woman’s decision for maternal employment is a function of her personal beliefs, preferences and context regarding paid work and care of the child. She adjusts her established work identity with her new identity as a mother. The second key theme from this research is that the women made their decisions for maternal employment in response to their personal context and there were different levels of opportunities between the women’s choices. There is inequity of entitlement regarding work conditions associated with a woman’s education level. This has implications for the woman’s engagement in paid work, and her child’s health and wellbeing. The third key theme is that the quality of the child’s care mattered to the women in the research. They preferred care provided by parents and/or relatives more than any other types of care. The fourth key theme identified that satisfaction and wellbeing outcomes experienced as a result of maternal employment decisions were a complex interaction between multiple factors that change across time with the ongoing development of the mother’s identity, and the development of the child. The implications for policy within Australia are that the employment of mothers in the workforce necessitates that non-parental care becomes a public concern, where there is universal access to good quality affordable care for every child, not just for those who can afford it. This is equitable and represents real choice while supporting the rights of the child (Thorpe, Cloney & Tayler, 2010), protecting and promoting the public interest (Cleveland & Krashinsky, 2010). Children’s health and wellbeing will be supported (Moore & Oberklaid, 2010) while children are in non-parental care, and they will be exposed to environments and experiences that support their learning and development. The significant design of the research enabled the trajectories of first-time expectant women to be tracked from the antenatal point to 12 months postpartum. But there were limitations: the small sample size, the over-representation of the sample being highly educated and the nature of a longitudinal research that is set within the economic, social and political context at that time. These limitations are discussed in relation to suggestions for future research.

Learning object dynamics for smooth tracking of moving lip contours

A new technique is proposed for learning the dynamic characteristics of a deformable object, applied in particular to the problem of lip-tracking. Experimental results are given which demonstrate that the use of dynamic models allows the system to track more robustly under adverse conditions and to correct spurious, poorly tracked frames

Tracking the Brisbane residential property market : Post GFC

Prior to the GFC, Brisbane and Perth were experiencing the highest increases in median residential house prices, compared to the other major Australian cities, due to strong demand for both owner occupied and investment residential property. In both these cities, a major driver of this demand and subsequent increases in residential property prices was the strong resources sector. With the onset of the GFC in 2008, the resources and construction sectors in Queensland contracted significantly and this had both direct and indirect impacts on the Brisbane residential property market. However, this impact was not consistent across Brisbane residential property sectors. The affect on houses and units differed, as did the impact based on geographic location and suburb value. This paper tracks Brisbane residential property sales listings, sales and returns over the period February 2009 to July 2010 and provides an analysis of the residential market for 24 Brisbane suburbs. These suburbs cover main residential areas of Brisbane and are based on an equal number of low, medium and high socioeconomic areas of Brisbane. This assessment of socio-economic status for the suburbs is based on both median household income and median house price. The analysis will cover both free standing residential property and residential units/townhouses/villas. The results will show how each of these residential property sub markets have performed following the GFC.

Error analysis and attitude observability of a monocular GPS/visual odometry integrated navigation filter

In this paper, we present a method for the recovery of position and absolute attitude (including pitch, roll and yaw) using a novel fusion of monocular Visual Odometry and GPS measurements in a similar manner to a classic loosely-coupled GPS/INS error state navigation filter. The proposed filter does not require additional restrictions or assumptions such as platform-specific dynamics, map-matching, feature-tracking, visual loop-closing, gravity vector or additional sensors such as an IMU or magnetic compass. An observability analysis of the proposed filter is performed, showing that the scale factor, position and attitude errors are fully observable under acceleration that is non-parallel to velocity vector in the navigation frame. The observability properties of the proposed filter are demonstrated using numerical simulations. We conclude the article with an implementation of the proposed filter using real flight data collected from a Cessna 172 equipped with a downwards-looking camera and GPS, showing the feasibility of the algorithm in real-world conditions.

The HarmonyGrid : music, space and performance in grid music systems

This research explores music in space, as experienced through performing and music-making with interactive systems. It explores how musical parameters may be presented spatially and displayed visually with a view to their exploration by a musician during performance. Spatial arrangements of musical components, especially pitches and harmonies, have been widely studied in the literature, but the current capabilities of interactive systems allow the improvisational exploration of these musical spaces as part of a performance practice. This research focuses on quantised spatial organisation of musical parameters that can be categorised as grid music systems (GMSs), and interactive music systems based on them. The research explores and surveys existing and historical uses of GMSs, and develops and demonstrates the use of a novel grid music system designed for whole body interaction. Grid music systems provide plotting of spatialised input to construct patterned music on a two-dimensional grid layout. GMSs are navigated to construct a sequence of parametric steps, for example a series of pitches, rhythmic values, a chord sequence, or terraced dynamic steps. While they are conceptually simple when only controlling one musical dimension, grid systems may be layered to enable complex and satisfying musical results. These systems have proved a viable, effective, accessible and engaging means of music-making for the general user as well as the musician. GMSs have been widely used in electronic and digital music technologies, where they have generally been applied to small portable devices and software systems such as step sequencers and drum machines. This research shows that by scaling up a grid music system, music-making and musical improvisation are enhanced, gaining several advantages: (1) Full body location becomes the spatial input to the grid. The system becomes a partially immersive one in four related ways: spatially, graphically, sonically and musically. (2) Detection of body location by tracking enables hands-free operation, thereby allowing the playing of a musical instrument in addition to “playing” the grid system. (3) Visual information regarding musical parameters may be enhanced so that the performer may fully engage with existing spatial knowledge of musical materials. The result is that existing spatial knowledge is overlaid on, and combined with, music-space. Music-space is a new concept produced by the research, and is similar to notions of other musical spaces including soundscape, acoustic space, Smalley's “circumspace” and “immersive space” (2007, 48-52), and Lotis's “ambiophony” (2003), but is rather more textural and “alive”—and therefore very conducive to interaction. Music-space is that space occupied by music, set within normal space, which may be perceived by a person located within, or moving around in that space. Music-space has a perceivable “texture” made of tensions and relaxations, and contains spatial patterns of these formed by musical elements such as notes, harmonies, and sounds, changing over time. The music may be performed by live musicians, created electronically, or be prerecorded. Large-scale GMSs have the capability not only to interactively display musical information as music representative space, but to allow music-space to co-exist with it. Moving around the grid, the performer may interact in real time with musical materials in music-space, as they form over squares or move in paths. Additionally he/she may sense the textural matrix of the music-space while being immersed in surround sound covering the grid. The HarmonyGrid is a new computer-based interactive performance system developed during this research that provides a generative music-making system intended to accompany, or play along with, an improvising musician. This large-scale GMS employs full-body motion tracking over a projected grid. Playing with the system creates an enhanced performance employing live interactive music, along with graphical and spatial activity. Although one other experimental system provides certain aspects of immersive music-making, currently only the HarmonyGrid provides an environment to explore and experience music-space in a GMS.

Toward automated power line corridor monitoring using advanced aircraft control and multisource feature fusion

The conventional manual power line corridor inspection processes that are used by most energy utilities are labor-intensive, time consuming and expensive. Remote sensing technologies represent an attractive and cost-effective alternative approach to these monitoring activities. This paper presents a comprehensive investigation into automated remote sensing based power line corridor monitoring, focusing on recent innovations in the area of increased automation of fixed-wing platforms for aerial data collection, and automated data processing for object recognition using a feature fusion process. Airborne automation is achieved by using a novel approach that provides improved lateral control for tracking corridors and automatic real-time dynamic turning for flying between corridor segments, we call this approach PTAGS. Improved object recognition is achieved by fusing information from multi-sensor (LiDAR and imagery) data and multiple visual feature descriptors (color and texture). The results from our experiments and field survey illustrate the effectiveness of the proposed aircraft control and feature fusion approaches.

Fat and thin adaptive HMM filters for vision based detection of moving targets

Computer vision is an attractive solution for uninhabited aerial vehicle (UAV) collision avoidance, due to the low weight, size and power requirements of hardware. A two-stage paradigm has emerged in the literature for detection and tracking of dim targets in images, comprising of spatial preprocessing, followed by temporal filtering. In this paper, we investigate a hidden Markov model (HMM) based temporal filtering approach. Specifically, we propose an adaptive HMM filter, in which the variance of model parameters is refined as the quality of the target estimate improves. Filters with high variance (fat filters) are used for target acquisition, and filters with low variance (thin filters) are used for target tracking. The adaptive filter is tested in simulation and with real data (video of a collision-course aircraft). Our test results demonstrate that our adaptive filtering approach has improved tracking performance, and provides an estimate of target heading not present in previous HMM filtering approaches.

SNP diversity of Enterococcus faecalis and Enterococcus faecium in a South East Queensland waterway, Australia, and associated antibiotic resistance gene profiles

BACKGROUND: Enterococcus faecalis and Enterococcus faecium are associated with faecal pollution of water, linked to swimmer-associated gastroenteritis and demonstrate a wide range of antibiotic resistance. The Coomera River is a main water source for the Pimpama-Coomera watershed and is located in South East Queensland, Australia, which is used intensively for agriculture and recreational purposes. This study investigated the diversity of E. faecalis and E. faecium using Single Nucleotide Polymorphisms (SNPs) and associated antibiotic resistance profiles. RESULTS: Total enterococcal counts (cfu/ml) for three/six sampling sites were above the United States Environmental Protection Agency (USEPA) recommended level during rainfall periods and fall into categories B and C of the Australian National Health and Medical Research Council (NHMRC) guidelines (with a 1-10% gastrointestinal illness risk). E. faecalis and E. faecium isolates were grouped into 29 and 23 SNP profiles (validated by MLST analysis) respectively. This study showed the high diversity of E. faecalis and E. faecium over a period of two years and both human-related and human-specific SNP profiles were identified. 81.8% of E. faecalis and 70.21% of E. faecium SNP profiles were associated with genotypic and phenotypic antibiotic resistance. Gentamicin resistance was higher in E. faecalis (47% resistant) and harboured the aac(6')-aph(2') gene. Ciprofloxacin resistance was more common in E. faecium (12.7% resistant) and gyrA gene mutations were detected in these isolates. Tetracycline resistance was less common in both species while tet(L) and tet(M) genes were more prevalent. Ampicillin resistance was only found in E. faecium isolates with mutations in the pbp5 gene. Vancomycin resistance was not detected in any of the isolates. We found that antibiotic resistance profiles further sub-divided the SNP profiles of both E. faecalis and E. faecium. CONCLUSIONS: The distribution of E. faecalis and E. faecium genotypes is highly diverse in the Coomera River. The SNP genotyping method is rapid and robust and can be applied to study the diversity of E. faecalis and E. faecium in waterways. It can also be used to test for human-related and human-specific enterococci in water. The resolving power can be increased by including antibiotic-resistant profiles which can be used as a possible source tracking tool. This warrants further investigation.

A nonlinear PI and backstepping based controller for tractor-steerable trailer influenced by slip

Autonomous guidance of agricultural vehiclesis vital as mechanized farming production becomes more prevalent. It is crucial that tractor-trailers are guided with accuracy in both lateral and longitudinal directions, whilst being affected by large disturbance forces, or slips, owing to uncertain and undulating terrain. Successful research has been concentrated on trajectory control which can provide longitudinal and lateral accuracy if the vehicle moves without sliding, and the trailer is passive. In this paper, the problem of robust trajectory tracking along straight and circular paths of a tractor-steerable trailer is addressed. By utilizing a robust combination of backstepping and nonlinear PI control, a robust, nonlinear controller is proposed. For vehicles subjected to sliding, the proposed controller makes the lateral deviations and the orientation errors of the tractor and trailer converge to a neighborhood near the origin. Simulation results are presented to illustrate that the suggested controller ensures precise trajectory tracking in the presence of slip.

Towards improving mission execution for autonomous gliders with an ocean model and Kalman filter

In this paper, we examine the use of a Kalman filter to aid in the mission planning process for autonomous gliders. Given a set of waypoints defining the planned mission and a prediction of the ocean currents from a regional ocean model, we present an approach to determine the best, constant, time interval at which the glider should surface to maintain a prescribed tracking error, and minimizing time on the ocean surface. We assume basic parameters for the execution of a given mission, and provide the results of the Kalman filter mission planning approach. These results are compared with previous executions of the given mission scenario.

Association between feeding style and weight gain in infants aged 2–7 months

Introduction: Feeding on demand supports an infant’s innate capacity to respond to hunger and satiety cues and may promote later self-regulation of intake. Our aim was to examine whether feeding style (on demand vs to schedule) is associated with weight gain in early life. Methods: Participants were first-time mothers of healthy term infants enrolled NOURISH, an RCT evaluating an intervention to promote positive early feeding practices. Baseline assessment occurred when infants were aged 2-7 months. Infants able to be categorised clearly as feeding on demand or to schedule (mothers self report) were included in the logistic regression analysis. The model was adjusted for gender, breastfeeding and maternal age, education, BMI. Weight gain was defined as a positive difference in baseline minus birthweight z-scores (WHO standards) which indicated tracking above weight percentile. Results: Data from 356 infants with a mean age of 4.4 (SD 1.0) months were available. Of these, 197 (55%) were fed on demand, 42 (12%) were fed on schedule. There was no statistical association between feeding style and weight gain [OR=0.72 (95%CI 0.35-1.46), P=0.36]. Formula fed infants were three times more likely to be fed on schedule and formula feeding was independently associated with increased weight gain [OR=2.02 (95%CI 1.11-3.66), P=0.021]. Conclusion: In this preliminary analysis the association between feeding style and weight gain did not reach statistical significance, however , the effect size may be clinically relevant and future analysis will include the full study sample (N=698).

Mothers of young children with special health care needs : maternal well-being and engagement in work

This thesis reports research focused on the well-being and employment experiences of mothers who have a child with special health care needs. Data are drawn from Growing Up in Australia: The Longitudinal Study of Australian Children (LSAC). This is a public access database. The thesis uses the social ecological theory of Bronfenbrenner (1984) and the work of Zubrick et al. (2000) on human and social capital to inform the conceptual framework developed for the research. Four studies are reported. LSAC has a nationally representative sample of Australian children and their families. The study is tracking the development of 10,000 children, with data collected every two years, from 2004 to 2018. This thesis uses data from the Kindergarten Cohort of LSAC. The 4,983 children in the Kindergarten Cohort were aged 4 years at recruitment into the study in 2004. The analyses in this thesis use child and family data from Wave 1 (2004) and Wave 2 (2006) for a subsample of the children who are identified as having special health needs. This identification is based on a short screening questionnaire included in the Parent 1 Interview at each wave of the data collection. It is the children who are identified as having special health care needs which can be broadly defined as chronic health conditions or developmental difficulties. However, it is the well-being and employment experiences of the mothers of these children that are the primary focus in three of the four studies reported in this thesis.