Efficient Voltage/Current Spike Reduction by Active Gate Signaling

This paper presents an Active Gate Signaling scheme to reduce voltage/current spikes across insulated gate power switches in hard switching power electronic circuits. Voltage and/or current spikes may cause EMI noise. In addition, they increase voltage/current stress on the switch. Traditionally, a higher gate resistance is chosen to reduce voltage/current spikes. Since the switching loss will increase remarkably, an active gate voltage control scheme is developed to improve efficiency of hard switching circuits while the undesirable voltage and/or current spikes are minimized.

When 'listeners can't talk' : comparing active listening in opening sequences of telephone and online counselling

While there is growing use of online counselling, little is known about its interactional organisation and how it compares to telephone counselling. This is despite past research suggesting that both counsellors and clients report the impact of the different modalities on the presentation and management of the counselling interaction. This paper compares the interactional affordances of telephone and online web counselling in opening sequences on Kids Help Line, a 24-hour Australian counselling service for children and young people up to the age of 25. We examine two ways that counsellors show active listening through response tokens and formulations. The analysis describes how counsellors’ use of minimal response tokens facilitate the clients’ problem presentation and are used in the management of turn taking and sequence organisation. For example, counsellors use the response token Mm hm to show that they understand that the client’s unit of talk to is not yet complete, and to affirm or invite the client to continue speaking. Formulations in phone and web counselling are another way that counsellors display active listening to re-present stretches of the clients’ preceding talk. In phone and web counselling, however, the respective modalities can complicate matters of turn transition and sequence organisation. By examining actual phone and online counselling sessions, this paper offers empirical demonstrations of the interactional affordances of phone and online counselling, and shows how the institutional practice of active listening is accomplished across different counselling modalities

Socio-cultural dimensions of Active Futures : Importance of studying migrants’ perspectives of wellness

In this paper we provide a migrant perspective on how women and men from a different culture perceive wellness while settling down in a new country. We are discussing the texts of research interviews with Indian migrant women and men that illuminate their perception of lifestyle enhancement in their adopted country Australia. Our purpose is to show how socio-cultural factors influence the migrants‟ perspective of lifestyle enhancement, and to what extent they direct their wellness. Personal development, both in theory and practice, is a huge concept in Australia. Concerted efforts are made towards increasing public awareness about health literacy leading to a better understanding and practice of wellness. However, as research studies have pointed out, lifestyle enhancement leading to holistic wellness is not void of socio-cultural factors. The number of women and men migrating to Australia from India has increased greatly in the present decade. As migrants their participation in developing Australian society is significant. So what is their socio-cultural perception of wellness including nutrition and physical exercises as active citizens? How do young Indian migrants participate in lifestyle enhancement programmes? As parents what are their socio-cultural beliefs, attitudes, practices and values, and how do they influence their children‟s participation in personal development and PE progammes? To what extent gender differences exist in such participation levels? What is the space available in State school curriculum to learn from the migrants‟ cultures towards enhancing lifestyles including nutrition and personal development?The findings may sensitise Australian researchers, academics, school teachers and practitioners of wellness therapies. Long term research studies may inform the governments and HPE practitioners of the changes occurring in such values, beliefs and practices as they incorporate nutrition and lifestyles of Australian society.

Fusing shrinking and expanding active contour models for robust IRIS segmentation

The performance of iris recognition systems is significantly affected by the segmentation accuracy, especially in non- ideal iris images. This paper proposes an improved method to localise non-circular iris images quickly and accurately. Shrinking and expanding active contour methods are consolidated when localising inner and outer iris boundaries. First, the pupil region is roughly estimated based on histogram thresholding and morphological operations. There- after, a shrinking active contour model is used to precisely locate the inner iris boundary. Finally, the estimated inner iris boundary is used as an initial contour for an expanding active contour scheme to find the outer iris boundary. The proposed scheme is robust in finding exact the iris boundaries of non-circular and off-angle irises. In addition, occlusions of the iris images from eyelids and eyelashes are automatically excluded from the detected iris region. Experimental results on CASIA v3.0 iris databases indicate the accuracy of proposed technique.

Active flow control bump design using hybrid Nash-game coupled to evolutionary algorithms

In this paper, the optimal design of an active flow control device; Shock Control Bump (SCB) on suction and pressure sides of transonic aerofoil to reduce transonic total drag is investigated. Two optimisation test cases are conducted using different advanced Evolutionary Algorithms (EAs); the first optimiser is the Hierarchical Asynchronous Parallel Evolutionary Algorithm (HAPMOEA) based on canonical Evolutionary Strategies (ES). The second optimiser is the HAPMOEA is hybridised with one of well-known Game Strategies; Nash-Game. Numerical results show that SCB significantly reduces the drag by 30% when compared to the baseline design. In addition, the use of a Nash-Game strategy as a pre-conditioner of global control saves computational cost up to 90% when compared to the first optimiser HAPMOEA.

Predicting active material utilisation in LiFePO4 electrodes using a multi-scale mathematical model

A mathematical model is developed to simulate the discharge of a LiFePO4 cathode. This model contains 3 size scales, which match with experimental observations present in the literature on the multi-scale nature of LiFePO4 material. A shrinking-core is used on the smallest scale to represent the phase-transition of LiFePO4 during discharge. The model is then validated against existing experimental data and this validated model is then used to investigate parameters that influence active material utilisation. Specifically the size and composition of agglomerates of LiFePO4 crystals is discussed, and we investigate and quantify the relative effects that the ionic and electronic conductivities within the oxide have on oxide utilisation. We find that agglomerates of crystals can be tolerated under low discharge rates. The role of the electrolyte in limiting (cathodic) discharge is also discussed, and we show that electrolyte transport does limit performance at high discharge rates, confirming the conclusions of recent literature.