A practical implementation of a continuous isotropic spherical omnidirectional drive

This paper presents a continuous isotropic spherical omnidirectional drive mechanism that is efficient in its mechanical simplicity and use of volume. Spherical omnidirectional mechanisms allow isotropic motion, although many are limited from achieving true isotropic motion by practical mechanical design considerations. The mechanism presented in this paper uses a single motor to drive a point on the great circle of the sphere parallel to the ground plane, and does not require a gearbox. Three mechanisms located 120 degrees apart provide a stable drive platform for a mobile robot. Results show the omnidirectional ability of the robot and demonstrate the performance of the spherical mechanism compared to a popular commercial omnidirectional wheel over edges of varying heights and gaps of varying widths.

Continuous biometric authentication : can it be more practical?

Continuous biometric authentication schemes (CBAS) are built around the biometrics supplied by user behavioural characteristics and continuously check the identity of the user throughout the session. The current literature for CBAS primarily focuses on the accuracy of the system in order to reduce false alarms. However, these attempts do not consider various issues that might affect practicality in real world applications and continuous authentication scenarios. One of the main issues is that the presented CBAS are based on several samples of training data either of both intruder and valid users or only the valid users' profile. This means that historical profiles for either the legitimate users or possible attackers should be available or collected before prediction time. However, in some cases it is impractical to gain the biometric data of the user in advance (before detection time). Another issue is the variability of the behaviour of the user between the registered profile obtained during enrollment, and the profile from the testing phase. The aim of this paper is to identify the limitations in current CBAS in order to make them more practical for real world applications. Also, the paper discusses a new application for CBAS not requiring any training data either from intruders or from valid users.

Enabling 21st century learning spaces : practical interpretations of the MCEETYA Learning Spaces Framework at Bounty Boulevard State School, Queensland, Australia

While the Queensland and Australian Governments have recognised the importance of new spaces for teaching and learning, particularly with the Rudd Government's Building the Education Revolution, the practical implementation of new spaces is largely left to schools and even individual teachers. This article proposes a theory for the consideration of 21st century learning spaces in relation to the learner, desired knowledge and understanding, digital technology and digital pedagogy. New and emerging learning spaces at Bounty Boulevard State School are analysed and critiqued through an analysis of the guiding principles offered by the 'Learning in an Online World: Learning Spaces Framework' (MCEETYA, 2008) publication, including flexibility, inclusivity, collaboration, creativity and efficiency. The argument put forward in this article is that 21st century learning spaces can be enabled while acknowledging barriers of resourcing and current ICT infrastructure.

Female genital mutilation : Australian law, policy and practical challenges for doctors

As long ago as 1994, the Family Law Council accepted it was likely that female genital mutilation (FGM) was being conducted in Australia. In 2010, doctors and hospitals reported that it is being conducted and that they are seeing female patients who have experienced FGM. It is impossible to obtain precise data about the extent to which it is performed in Australia, but data indicates that FGM is a relevant issue for Australian medical practitioners. The medical profession has an interest in this topic because its members may be asked to conduct FGM, advise those considering it, or treat female patients with effects from the practice. This article provides a background on the practice of FGM, explains the relevant Australian law, considers whether the current legal prohibition on FGM is justified, and discusses the practical challenges facing individual practitioners and the profession. To inform further discussions about methods of responding to demand for FGM, reference is made to strategies being promoted in African nations to abolish this cultural practice.

Towards practical implementation of time optimal trajectories for underwater vehicles

In this paper, we are concerned with the practical implementation of time optimal numerical techniques on underwater vehicles. We briefly introduce the model of underwater vehicle we consider and present the parameters for the test bed ODIN (Omni-Directional Intelligent Navigator). Then we explain the numerical method used to obtain time optimal trajectories with a structure suitable for the implementation. We follow this with a discussion on the modifications to be made considering the characteristics of ODIN. Finally, we illustrate our computations with some experimental results.

Book review : Kellett, M (2010) Rethinking children and research : attitudes in contemporary society

Rethinking Children and Research characterizes Mary Kellett’s vision as campaigner and sociologist actively working for and with children for many years. The book itself is not only visionary; it is informative, thought provoking and pragmatic. From a contemporary standpoint, the manuscript presents a detailed synopsis of the shifts in thinking about research with children and provides an appraisal of the theoretical movements that have driven a participatory research agenda. A strong theoretical approach of the combined lenses of sociologies of childhood and rights discourse is introduced early in the book. From the outset, the reader receives loud and clear, the key message of the book: that children in research should and can be included as competent members who lead research in the study of their everyday lives. The argument for a more mutual research approach is shaped throughout the book using research examples and practical suggestions on how this might be achieved. Overall, the reader is left feeling compelled to adopt such an approach.

Practical introduction to development of sage applications

Throughout this workshop session we have looked at various configurations of Sage as well as using the Sage UI to run Sage applications (e.g. the image viewer). More advanced usage of Sage has been demonstrated using a Sage compatible version of Paraview highlighting the potential of parallel rendering. The aim of this tutorial session is to give a practical introduction to developing visual content for a tiled display using the Sage libraries. After completing this tutorial you should have the basic tools required to develop your own custom Sage applications. This tutorial is designed for software developers and intermediate programming knowledge is assumed, along with some introductory OpenGL . You will be required to write small portions of C/C++ code to complete this worksheet. However if you do not feel comfortable writing code (or have never written in C or C++), we will be on hand throughout this session so feel free to ask for some help. We have a number of machines in this lab running a VNC client to a virtual machine running Fedora 12. You should all be able to log in with the username “escience”, and password “escience10”. Some of the commands in this worksheet require you to run them as the root user, so note the password as you may need to use it a few times. If you need to access the Internet, then use the username “qpsf01”, password “escience10”

Practical application of pseudospectral optimization to robot path planning

To obtain minimum time or minimum energy trajectories for robots it is necessary to employ planning methods which adequately consider the platform’s dynamic properties. A variety of sampling, graph-based or local receding-horizon optimisation methods have previously been proposed. These typically use simplified kino-dynamic models to avoid the significant computational burden of solving this problem in a high dimensional state-space. In this paper we investigate solutions from the class of pseudospectral optimisation methods which have grown in favour amongst the optimal control community in recent years. These methods have high computational efficiency and rapid convergence properties. We present a practical application of such an approach to the robot path planning problem to provide a trajectory considering the robot’s dynamic properties. We extend the existing literature by augmenting the path constraints with sensed obstacles rather than predefined analytical functions to enable real world application.

Regrounding critical literacy : representation, facts and reality

A discussion of the pivotal theoretical and practical issue in the teaching of critical literacies: the relationship between representation and material social, economic and ecosystemic reality. The argument here is that models of critical literacy are contingent upon a principled and grounded pursuit of material social, economic and ecological realities 'outside' of textual representation per se.

Investigating and theorizing discourse during analogy writing in chemistry

Explanations of the role of analogies in learning science at a cognitive level are made in terms of creating bridges between new information and students’ prior knowledge. In this empirical study of learning with analogies in an 11th grade chemistry class, we explore an alternative explanation at the "social" level where analogy shapes classroom discourse. Students in the study developed analogies within small groups and with their teacher. These classroom interactions were monitored to identify changes in discourse that took place through these activities. Beginning from socio-cultural perspectives and hybridity, we investigated classroom discourse during analogical activities. From our analyses, we theorized a merged discourse that explains how the analog discourse becomes intertwined with the target discourse generating a transitional state where meanings, signs, symbols, and practices are in flux. Three categories were developed that capture how students intertwined the analog and target discourses—merged words, merged utterances/sentences, and merged practices.

The bondage of an imposed visual discourse : understanding the built environment's influence on the 'oldest-old' aged care residents' sense of peace

This study investigates the influence of the built environment upon residents' sense of familiarity, concept of self and thus, their facilitation of place through the theory of "The Bondage of Imposed Visual Discourse". Simone de Beauvoir's theory "The Bondage of Feminine Elegance" provides the conceptual understanding of the visual discourse between the physicality of clothing and the wearer's personal identity. This fashion theory is transposed to explore the influence of the built environment's physicality upon aged care residents' personal identity. This paper presents findings from a study of professionals' opinions in reference to the built environment of permanent residential aged care for the 'oldest-old' of Australia. The researcher conducted qualitative interviews with four participants: an architect, occupational therapist, nursing home facility manager and an aged care lobbyist in the South-East Queensland. This study is structured towards proposing "place-focused" qualitative design principles to encourage residents' sense of place through the built environment. These proposed principles are addressed with reference to existing Standards and Principles outlined by the Australian Government.

Acquire a practical overview of 'good faith' in commercial contracting

The twists and turns in the ongoing development of the implied common law good faith obligation in the commercial contractual arena continue to prove fertile academic ground. Despite a lack of guidance from the High Court, the lower courts have been besieged by claims based, in part, on the implied obligation. Although lower court authority is lacking consistency and the ‘decisions in which lower courts have recognised the legitimacy of implication of a term of good faith vary in their suggested rationales’, the implied obligation may provide some comfort to a party to ‘at least some commercial contracts’ faced with a contractual counterpart exhibiting symptoms of bad faith.

Investigating child participation in the everyday talk of teacher and children in a preparatory year

In early years research, policy and education, a democratic perspective that positions children as participants and citizens is increasingly emphasized. These ideas take seriously listening to children’s opinions and respecting children’s influence over their everyday affairs. While much political and social investment has been paid to the inclusion of participatory approaches little has been reported on the practical achievement of such an approach in the day to day of early childhood education within school settings. This paper investigates talk and interaction in the everyday activities of a teacher and children in an Australian preparatory class (for children age 4-6 years) to see how ideas of child participation are experienced. We use an interactional analytic approach to demonstrate how participatory methods are employed in practical ways to manage routine interactions. Analysis shows that whilst the teacher seeks the children’s opinion and involves them in decision-making, child participation is at times constrained by the context and institutional categories of “teacher” and “student” that are jointly produced in their talk. The paper highlights tensions that arise for teachers as they balance a pedagogical intent of “teaching” and the associated institutional expectations, with efforts to engage children in decision-making. Recommendations include adopting a variety of conversational styles when engaging with children; consideration of temporal concerns and the need to acknowledge the culture of the school.

Practical stability of approximating discrete-time filters with respect to model mismatch using relative entropy concepts

This paper establishes practical stability results for an important range of approximate discrete-time filtering problems involving mismatch between the true system and the approximating filter model. Using local consistency assumption, the practical stability established is in the sense of an asymptotic bound on the amount of bias introduced by the model approximation. Significantly, these practical stability results do not require the approximating model to be of the same model type as the true system. Our analysis applies to a wide range of estimation problems and justifies the common practice of approximating intractable infinite dimensional nonlinear filters by simpler computationally tractable filters.