Design & performance of a networked ad-hoc acoustic communications system using inexpensive commercial CDMA modems

We present a new approach for creating and implementing an ad-hoc underwater acoustic sensor network based on connecting a small processor to the serial port of a commercial CDMA acoustic modem. The processor acts as a "node controller" providing the networking layer that the modems lack. The ad-hoc networking protocol is based on a modified dynamic source routing (DSR) approach and can be configured for maximising information throughput or minimising energy expenditure. The system was developed in simulation and then evaluated during field trials using a 10 node deployment. Experimental results show reliable multi-hop networking under a variety of network configurations, with the added ability to determine internode ranges to within 1.5 m for localisation.

IMU aided 3D visual odometry for car-like vehicles

We present a method for calculating odome- try in three-dimensions for car-like ground ve- hicles with an Ackerman-like steering model. In our approach we use the information from a single camera to derive the odometry in the plane and fuse it with roll and pitch informa- tion derived from an on-board IMU to extend to three-dimensions, thus providing odometric altitude as well as traditional x and y transla- tion. We have mounted the odometry module on a standard Toyota Prado SUV and present results from a car-park environment as well as from an off-road track.

Double star chopper cell converter for battery electric vehicles with inter-module SoC balancing and fault tolerant control

A modularized battery system with Double Star Chopper Cell (DSCC) based modular multilevel converter is proposed for a battery operated electric vehicle (EV). A design concept for the modularized battery micro-packs for DSCC is described. Multidimensional pulse width modulation (MD-PWM) with integrated inter-module SoC balancing and fault tolerant control is proposed and explained. The DSCC can be operated either as an inverter to drive the EV motor or as a synchronous rectifier connected to external three phase power supply equipment for charging the battery micro-packs. The methods of operation as inverter and synchronous rectifier with integrated inter-module SoC balancing and fault tolerant control are discussed. The proposed system operation as inverter and synchronous rectifier are verified through simulations and the results are presented.

Transitioning to energy efficient vehicles: An analysis of the potential rebound effects and subsequent impact upon emissions

Given the shift toward energy efficient vehicles (EEVs) in recent years, it is important that the effects of this transition are properly examined. This paper investigates some of these effects by analyzing annual kilometers traveled (AKT) of private vehicle owners in Stockholm in 2008. The difference in emissions associated with EEV adoption is estimated, along with the effect of a congestion-pricing exemption for EEVs on vehicle usage. Propensity score matching is used to compare AKT rates of different vehicle owner groups based on the treatments of: EEV ownership and commuting across the cordon, controlling for confounding factors such as demographics. Through this procedure, rebound effects are identified, with some EEV owners found to have driven up to 12.2% further than non-EEV owners. Although some of these differences could be attributed to the congestion-pricing exemption, the results were not statistically significant. Overall, taking into account lifecycle emissions of each fuel type, average EEV emissions were 50.5% less than average non-EEV emissions, with this reduction in emissions offset by 2.0% due to rebound effects. Although it is important for policy-makers to consider the potential for unexpected negative effects in similar transitions, the overall benefit of greatly reduced emissions appears to outweigh any rebound effects present in this case study.

Issues in autonomous navigation of underground vehicles

This paper describes current research at the Australian Centre for Field Robotics (ACFR) in collaboration with the Commonwealth Scientific and Industrial Research Organisation (CSIRO) within the Cooperative Research Centre (CRC) for Mining Technology and Equipment (CMTE) towards achieving autonomous navigation of underground vehicles, like a Load-Haul-Dump (LHD) truck. This work is being sponsored by the mining industry through the Australian Mineral Industries Research Association Limited (AMIRA). Robust and reliable autonomous navigation can only be realised by achieving high level tasks such as path-planning and obstacle avoidance. This requires determining the pose (position and orientation) of the vehicle at all times. A minimal infrastructure localisation algorithm that has been developed for this purpose is outlined and the corresponding results are presented. Further research issues that are under investigation are also outlined briefly.

Issues in obstacle detection for autonomous mining and construction vehicles

This paper discusses a Dumber of key issues for the development of robust, obstacle detection systems for autonomous mining and construction vehicles. A taxonomy of obstacle detection systems is described; An overview of the state-of- the-art in obstacle detection for outdoor autonomous vehicles is presented with their applicability to the mining and construction environments noted. The issue of so-called fail-safe obstacle detection is then discussed. Finally, we describe the development of an obstacle detection system for a mining vehicle.

Automation of underground LHD and truck haulage

This paper reviews the state-of-the-art in the automation of underground mining vehicles and reports on the development of an autonomous navigation system under development through the CMTE with sponsorship arranged by AMIRA. Past attempts at automating LHDs and haul trucks are described and their particular strengths and weaknesses are discussed. The auto-guidance system being developed overcomes some of the limitations of state-of-the-art prototype æcommercialÆ systems. It can be retrofitted to existing remote controlled vehicles, uses minimum installed infrastructure and is flexible enough for rapid relocation to alternate routes. The navigation techniques use data fusion of two separate sets of sensors combining natural feature recognition, nodal maps and inertial navigation techniques. Collision detection is incorporated and people and other traffic are excluded from the tramming area. This paper describes the work being done by the group with regard to auto-tramming and also outlines the future goals.

3D reconfigurable autopilot flight system for both general aviation and unmanned aerial systems

This research project investigated and designed a modular architecture for a 3D Reconfigurable Autopilot Flight System that could be used to control actuators in both manned and unmanned aircraft. The system is based on a CAN Bus interface and allows seamless control of different types of actuators. During the course of the research the differences and similarities of autopilots for fixed-wing general aviation aircraft and unmanned aircraft were analysed focusing on the actuator interfaces. This project suggests that software and hardware used in commercial-of-the-shelf avionics could be used in manned and unmanned aviation.

Ants, apples and the ABCs: The use of commercial phonics programmes in prior-to-school children's services

Commercial phonics programmes (e.g. Jolly Phonics and Letterland) are becoming widely used in the early years of school. These programmes claim to use a systematic explicit approach, considered as the preferred method of phonics instruction for teaching alphabetic code-breaking skills in Australia and the UK in the first years of school (Department of Education, Science and Training, 2005; Rose, 2006). However, little is known about the extent to which they are being used in prior-to-school settings, and the reasons behind decisions to use them. This study surveyed 283 early childhood staff in Sydney, Australia and found that commercial phonics programmes were being used in 36% of the early childhood settings surveyed. Staff with early childhood univer- sity qualifications and staff working in not-for-profit service types were less likely to use a commercial phonics programme than staff without university qualifications and staff working in for-profit services. Staff with less than 10 years’ experience were also more likely to use a commercial phonics programme. The rationale behind decisions deter- mining whether or not staff used the programmes ranged from pragmatic reasons, such as parent pressure or higher management decisions, to pedagogical reasons, such as teacher beliefs about how children learn to read and write. The practices staff engage in to teach phonics are explored.

Comparison of charged nanoparticle concentrations near busy roads and overhead high-voltage power lines

Overhead high-voltage power lines are known sources of corona ions. These ions rapidly attach to aerosols to form charged particles in the environment. Although the effect of ions and charged particles on human health is largely unknown, much attention has focused on the increasing exposure as a result of the expanding power network in urban residential areas. However, it is not widely known that a large number of charged particles in urban environments originate from motor vehicle emissions. In this study, for the first time, we compare the concentrations of charged nanoparticles near busy roads and overhead power lines. We show that large concentrations of both positive and negative charged nanoparticles are present near busy roadways and that these concentrations commonly exceed those under high-voltage power lines. We estimate that the concentration of charged nanoparticles found near two freeways carrying around 120 vehicles per minute exceeded the corresponding maximum concentrations under two corona-emitting overhead power lines by as much as a factor of 5. The difference was most pronounced when a significant fraction of traffic consisted of heavy-duty diesel vehicles which typically have high particle and charge emission rates.

Australian Commercial Law

Australian Commercial Law offers a concise yet comprehensive introduction to commercial law in Australia. The textbook provides a thorough and detailed discussion of a variety of topics in commercial law such as agency, bailment, the sale of goods, the transfer of property and the Personal Property Securities Act. The book also offers a detailed overview of topics within the Australian Consumer Law that are now relevant to commercial practice such as unconscionable conduct, consumer guarantees, and misleading and deceptive conduct. Written in a clear and accessible style, each chapter features key points and further reading to enhance students' understanding. Significant cases are discussed in detail and include excerpts from judgments to illustrate points of law. Australian Commercial Law is an indispensable resource for students who are seeking a comprehensive understanding of commercial law.

Designing and evaluating a persuasive child restraint television commercial

Objective Relatively high rates of child restraint inappropriate use, misuse and faults in the installation of restraints have suggested a crucial need for public education messages to raise parental awareness of the need to use restraints correctly. This project involved the devising and pilot testing of message concepts, filming of a television advertisement (the TVC), and the evaluation of the TVC. This paper focuses specifically upon the evaluation of the TVC. The development and evaluation of the TVC were guided by an extended Theory of Planned Behaviour which comprised the standard constructs of attitude, subjective norm, and perceived behavioural control as well as the additional constructs of group norm and descriptive norm. The study also explored the extent to which parents with low and high intentions to self-check restraint/s differed on salient beliefs regarding the behaviour. Methods An online survey of parents (N = 384) was conducted where parents were randomly assigned to either an Intervention group (n = 161), and therefore viewed the advertisement within the survey, or the Control group (n = 223) and therefore did not view the advertisement. Results Following a one-off exposure to the TVC, the results indicated that, although not a significant difference, parents in the Intervention group reported stronger intentions (M = 4.43, SD = .74) to self-check restraints than parents in the Control group (M = 4.18, SD = .86). Also, parents in the Intervention group (M = 4.59, SD = .47) reported significantly higher levels of perceived behavioural control than parents in the Control group (M = 4.40, SD = .73). The regression results revealed that, for parents in the Intervention group, attitude and group norm were significant predictors of parental intentions to self-check their child restraint. Finally, the exploratory analyses of parental beliefs suggested that those parents with low intentions to self-check child restraints were significantly more likely than high intenders to agree that they did not have enough time to check restraints or that having a child in a restraint is more important than checking the installation of the restraint. Conclusion Overall, the findings provide some support for the persuasiveness of the child restraint TVC and provide insight into the factors influencing reported parental intentions as well as salient beliefs underpinning self-checking of restraints. Interventions that attempt to increase parental perceptions of the importance of self-checking restraints regularly and brevity of the time involved in doing so may be effective.

A simple approach to improve the electrocatalytic properties of commercial Pt/C

Here we demonstrate that commercial carbon supported Pt nanoparticles react with [AuCl4]- ions at room temperature to produce a highly active Au/Pt/C material with an ultralow coverage of elemental Au on the Pt nanoparticles that exhibits significantly enhanced activity for ethanol oxidation when compared to Pt/C.