Clustering of ad-hoc microphone arrays for robust blind beamforming

This paper proposes a clustered approach for blind beamfoming from ad-hoc microphone arrays. In such arrangements, microphone placement is arbitrary and the speaker may be close to one, all or a subset of microphones at a given time. Practical issues with such a configuration mean that some microphones might be better discarded due to poor input signal to noise ratio (SNR) or undesirable spatial aliasing effects from large inter-element spacings when beamforming. Large inter-microphone spacings may also lead to inaccuracies in delay estimation during blind beamforming. In such situations, using a cluster of microphones (ie, a sub-array), closely located both to each other and to the desired speech source, may provide more robust enhancement than the full array. This paper proposes a method for blind clustering of microphones based on the magnitude square coherence function, and evaluates the method on a database recorded using various ad-hoc microphone arrangements.

One-time-password-authenticated key exchange

To reduce the damage of phishing and spyware attacks, banks, governments, and other security-sensitive industries are deploying one-time password systems, where users have many passwords and use each password only once. If a single password is compromised, it can be only be used to impersonate the user once, limiting the damage caused. However, existing practical approaches to one-time passwords have been susceptible to sophisticated phishing attacks. ---------- We give a formal security treatment of this important practical problem. We consider the use of one-time passwords in the context of password-authenticated key exchange (PAKE), which allows for mutual authentication, session key agreement, and resistance to phishing attacks. We describe a security model for the use of one-time passwords, explicitly considering the compromise of past (and future) one-time passwords, and show a general technique for building a secure one-time-PAKE protocol from any secure PAKE protocol. Our techniques also allow for the secure use of pseudorandomly generated and time-dependent passwords.

Predicate-based key exchange

We provide the first description of and security model for authenticated key exchange protocols with predicate-based authentication. In addition to the standard goal of session key security, our security model also provides for credential privacy: a participating party learns nothing more about the other party's credentials than whether they satisfy the given predicate. Our model also encompasses attribute-based key exchange since it is a special case of predicate-based key exchange.---------- We demonstrate how to realize a secure predicate-based key exchange protocol by combining any secure predicate-based signature scheme with the basic Diffie-Hellman key exchange protocol, providing an efficient and simple solution.

Investigating users’ intuitive interaction with complex artefacts

This paper examines the role of intuition in the way that people operate unfamiliar devices. Intuition is a type of cognitive processing that is often non-conscious and utilises stored experiential knowledge. Intuitive interaction involves the use of knowledge gained from other products and/or experiences. Two initial experimental studies revealed that prior exposure to products employing similar features helped participants to complete set tasks more quickly and intuitively, and that familiar features were intuitively used more often than unfamiliar ones. A third experiment confirmed that performance is affected by a person's level of familiarity with similar technologies, and also revealed that appearance (shape, size and labelling of features) seems to be the variable that most affects time spent on a task and intuitive uses during that time. Age also seems to have an effect. These results and their implications are discussed.

Sustainable airport infrastructure : balancing infrastructures for the airport metropolis

Ongoing financial, environmental and political adjustments have shifted the role of large international airports. Many airports are expanding from a narrow concentration on operating as transportation centres to becoming economic hubs. By working together, airports and other industry sectors can contribute to and facilitate not only economic prosperity, but create social advantage for local and regional areas in new ways. This transformation of the function and orientation of airports has been termed the aerotropolis or airport metropolis, where the airport is recognised as an economic centre with land uses that link local and global markets. This chapter contends that the conversion of an airport into a sustainable airport metropolis requires more than just industry clustering and the existence of hard physical infrastructure. Attention must also be directed to the creation and on-going development of social infrastructure within proximate areas and the maximisation of connectivity flows within and between infrastructure elements. It concludes that the establishment of an interactive and interdependent infrastructure trilogy of hard, soft and social infrastructures provides the necessary balance to the airport metropolis to ensure sustainable development. This chapter provides the start of an operating framework to integrate and harness the infrastructure trilogy to enable the achievement of optimal and sustainable social and economic advantage from airport cities.

Towards a culturally appropriate mental health system: Sudanese-Australians' experiences with trauma

Australia is fortunate to welcome approximately 13,000 humanitarian entrants per year, most of whom have experienced protracted violence, hardship and life in refugee camps. The majority of humanitarian migrants were raised in cultural contexts very different to that of Australia, contributing to the increasing diversity of this region. With this diversity comes a responsibility to ensure every Australian receives culturally appropriate mental healthcare. Those who are forced into migration have experienced trauma and the stress of acculturation often compounds this trauma. This study investigated the experience of trauma from the perspectives of Sudanese-Australians. Grounded theory methodology was employed to extract themes from interviews with 15 Sudanese-Australians aged between 19 and 49 years. Results demonstrated four overarching themes: support, religion, strength and new possibilities. The data within these themes are compared and contrasted with previous literature that has examined notions of trauma, distress and growth in western populations. Conclusions drawn from these results highlight the need to build inclusive practices that support diversity into existing trauma services in Australia.

Shared leadership in Queensland schools : a collective case study

Shared leadership has been identified as a key governance base for the future of government and Catholic schools in Queensland, the state’s two largest providers of school education. Shared leadership values the contributions that many individuals can make through collaboration and teamwork. It claims to improve organisational performance and reduce the increasing pressures faced by principals. However despite these positive features, shared leadership is generally not well understood, not well accepted and not valued by those who practice or study leadership. A collective case study method was chosen, incorporating a series of semi-structured interviews with principals and the use of official school documents. The study has explored the current understanding and practice of shared leadership in four Queensland schools and investigated its potential for use.

Fixed argument pairings

A common scenario in many pairing-based cryptographic protocols is that one argument in the pairing is fixed as a long term secret key or a constant parameter in the system. In these situations, the runtime of Miller's algorithm can be significantly reduced by storing precomputed values that depend on the fixed argument, prior to the input or existence of the second argument. In light of recent developments in pairing computation, we show that the computation of the Miller loop can be sped up by up to 37 if precomputation is employed, with our method being up to 19.5 faster than the previous precomputation techniques.

Listen and learn

The communities located adjacent to and around the Airport City are composed of diverse interests and cultures that often have little to do with the airport and its global service functions. Yet, as most airport managers know, these communities can have a significant impact on airport operations and land use. Community engagement is an essential element to airport planning and management that is often underplayed and given only a token effort. In order for Airport Cities to realize their full potential in global and national markets as well as assume an appropriate level of corporate responsibility there needs to be a strong and enduring connections to local and regional communities. Through a series of nationally held workshops throughout Australia and internationally, we have reviewed the complex relationship between airports and their surrounding communities. We argue the following engagement elements improve both communication and relationships with local communities and must be actively nurtured, developed and pursued by airport managers: connectivity, collaboration and citizenry.

Further results with localization and mapping using range from radio

In this paper, we present recent results with using range from radio for mobile robot localization. In previous work we have shown how range readings from radio tags placed in the environment can be used to localize a robot. We have extended previous work to consider robustness. Specifically, we are interested in the case where range readings are very noisy and available intermittently. Also, we consider the case where the location of the radio tags is not known at all ahead of time and must be solved for simultaneously along with the position of the moving robot. We present results from a mobile robot that is equipped with GPS for ground truth, operating over several km.

Visual motion estimation for an autonomous underwater reef monitoring robot

Performing reliable localisation and navigation within highly unstructured underwater coral reef environments is a difficult task at the best of times. Typical research and commercial underwater vehicles use expensive acoustic positioning and sonar systems which require significant external infrastructure to operate effectively. This paper is focused on the development of a robust vision-based motion estimation technique using low-cost sensors for performing real-time autonomous and untethered environmental monitoring tasks in the Great Barrier Reef without the use of acoustic positioning. The technique is experimentally shown to provide accurate odometry and terrain profile information suitable for input into the vehicle controller to perform a range of environmental monitoring tasks.

Field and Service Robotics Results of the 5th International Conference

The 5th International Conference on Field and Service Robotics (FSR05) was held in Port Douglas, Australia, on 29th - 31st July 2005, and brought together the worlds' leading experts in field and service automation. The goal of the conference was to report and encourage the latest research and practical results towards the use of field and service robotics in the community with particular focus on proven technology. The conference provided a forum for researchers, professionals and robot manufacturers to exchange up-to-date technical knowledge and experience. Field robots are robots which operate in outdoor, complex, and dynamic environments. Service robots are those that work closely with humans, with particular applications involving indoor and structured environments. There are a wide range of topics presented in this issue on field and service robots including: Agricultural and Forestry Robotics, Mining and Exploration Robots, Robots for Construction, Security & Defence Robots, Cleaning Robots, Autonomous Underwater Vehicles and Autonomous Flying Robots. This meeting was the fifth in the series and brings FSR back to Australia where it was first held. FSR has been held every 2 years, starting with Canberra 1997, followed by Pittsburgh 1999, Helsinki 2001 and Lake Yamanaka 2003.

A planning support system for airport city development

Many airports around the world are diversifying their land use strategies to integrate non-aeronautical development. These airports embrace the “airport city” concept to develop a wide range of commercial and light industrial land uses to support airport revenues. The consequences of this changing urban form are profound for both airport and municipal planners alike and present numerous challenges with regard to integration of airport and regional planning. While several tools exist for regional planning and airport operational planning, no holistic airport landside and regional planning tool exist. What is required is a planning support system that can integrate the sometimes conflicting stakeholder interests into one common goal for the airport and the surrounding region. This paper presents a planning support system and evaluates its application to a case study involving Brisbane Airport and the South East Queensland region in Australia.

Challenges in land use planning around Australian airports

The privatization of major Australian airports in the late 1990s unleashed an unprecedented development wave as corporate lessees implemented ambitious business plans. While planning and environmental regulations governing on-airport development were significantly enhanced, there has been national disquiet about a governance regime that remains under the auspices of the federal government and is not effectively integrated into state and local decision-making machinery. Tensions in major airport regions have been exacerbated by the building of highly conspicuous non-aeronautical developments approved with no determining input by local decision-makers as well as the growing pressures on off-airport locations for aviation-related development. This paper canvasses this context and overviews the evolving structure of planning controls for Australia’s privatized federal airports. A range of issues surfacing through the National Aviation Policy Review process in 2008–2009 is described.

Optimising figure of merit for phonetic spoken term detection

This paper introduces a novel technique to directly optimise the Figure of Merit (FOM) for phonetic spoken term detection. The FOM is a popular measure of sTD accuracy, making it an ideal candiate for use as an objective function. A simple linear model is introduced to transform the phone log-posterior probabilities output by a phe classifier to produce enhanced log-posterior features that are more suitable for the STD task. Direct optimisation of the FOM is then performed by training the parameters of this model using a non-linear gradient descent algorithm. Substantial FOM improvements of 11% relative are achieved on held-out evaluation data, demonstrating the generalisability of the approach.