FDTD modeling of heatsink RF characteristics for EMC mitigation

Due to their size and complex geometry, large heatsinks such as those used in the power electronics industry may enhance the radiated emissions produced by the circuits employing them. Such enhancement of the radio frequency (rf) radiation could cause the equipment to malfunction or to contravene current EMC regulations. In this paper, the electromagnetic resonant effects of heatsinks are examined using the finite-difference time-domain (FDTD) method and recommendations are made concerning the optimum geometry of heatsinks and the placement of components so as to mitigate potential EMC effects

Non-Contact Torque Transfer Using Ferrofluid

Gearing systems are a mechanical based systems that allow an input shaft torque to increase or decrease when it is transferred as an output shaft. Although the gearing system is an old creation that holds little mysteries in the current day, the complexities used to adapt it to new applications continues to grow. The invention discussed and researched in this paper goes in depth on how the gearing system was redesigned to accommodate new uses along with making the system more efficient. A gearing system uses a solid surface to surface contact to transfer the torque from input to output. Overtime, the solid contact surface deteriorate due to friction and inefficiencies causing the destruction of the system in order to produce longer lasting gearing system that require less maintenance and reduce the wear within the system, a more efficient and durable process must be implemented. This paper discusses the redesign of the common gearing system referred to as the non-contact torque transfer using ferrofluid. The ferrofluid gearing system was created within the bounds specified by the sponsor, Dr. Nassersharif. It has been designed to outlast other gearing systems, making it appeal to the customer demand through implementing magnets and ferrofluid. Through calculations and physical observations, the ferrofluid gearing system proved to work and the design concept is able to be patented

The presence and place of students who are not Catholic in Catholic schools: An analysis of official church documents

In many Australian Catholic schools, students who are not Catholics are increasingly seeking enrolment. While such students have always been present in Catholic schools their numbers have increased in recent years (Welboume, 2001). In NSW Catholic schools, for instance, the number of these students has doubled in percentage terms in the past 15 years to around five percent of the total student population, while the total increase in students has been marginal (NSWCEC, 2003). The growing presence of students who are not Catholics in Catholic schools raises "questions about the changing nature and purpose of the Catholic school as a context for religious education" (Welboume, 2003, p. 1). These questions focus on the nature and purpose of the classroom religion program and the evangelical and catechetical possibilities that form part of the Catholic school's pastoral mission. This article presents the results of an analysis of extracts from official Catholic church documents on education and catechesis concerning the enrolment in Catholic schools of students who are not Catholics. Membership Categorisation Analysis is the tool of analysis used to review these documents. The discussion of results and findings provides directions for further research as well as questions for reflection for school administrators and religious educators. The Church documents selected for study here are those deemed influential on the theory and practice of Catholic schools. Free body (2003, p. 179) argues that understanding how texts operate is critical for educators because: contemporary educational practice is saturated by texts; public educational arrangements are defined and regulated by texts; and, public educational activities are challenged, changed and legitimated by texts. Freebody's second point, "public educational arrangements are defined and regulated by texts", is central to this study. For religious educators and leaders in Catholic schools, the official church documents on education and catechesis define and regulate practices in Catholic schools. This article poses two main questions for these official documents. First, how do church officials regard the presence in Catholic schools of students who are not Catholics? This question seeks to judge the extent to which these students are welcome in Catholic schools. Second, what is the place of these students in Catholic schools? This question examines what is expected of these students when they attend a Catholic school

Personal Information Interfaces

poster abstractAs the ubiquitous computing vision of “computation everywhere” has become increasingly mainstream, people make use of electronic information across multiple form factors, in more places, as part of more activities, and in more social contexts than ever before. This is the crux of the information overload problem: with a vast increase in exposure to information, there is a corresponding increase in the amount of work that people need to invest to keep up with the demands of perceiving, sense-making, organizing, utilizing, and managing that information. Dr. Stephen Voida and his student researchers in the Personal Information Interfaces (PII) laboratory explore ways that the interfaces, interaction techniques, and context-aware infrastructure employed in the next generation of information systems might better respond to the critical, real-world challenges associated with information overload. A new generation of sensor-enabled computing devices stands to magnify the information overload effect by adding streams of data about our environment, our working contexts, and traces of our activities—both online and in the real world—into the mix. A popular example is the growing number of fitness tracking devices that have appeared on the market in the last few years, for example, Fitbits, Nike+ Fuelbands, and the Jawbone Up (just to name a few). Proponents of the “quantified self” movement suggest one way to use the data streams provided by these devices: as a means for self-reflection. However, effective self-reflection requires that a vast amount of information—often highly personal in nature—be captured by our devices, and it introduces new work for end-users, such as finding patterns in the data and translating sensed trends into effective actions. We are currently launching a study of commercial fitness trackers to understand when different representations of self-reflective data streams are effective in helping to facilitate behavior change…and when those representations contribute instead to a sense of information overload. We are also exploring similar questions related to other technologies that collect and present self-reflective data about daily life—time management tools, mood-tracking apps, and the like. In general, we aim to understand how infrastructure and interface design can prevent people’s experiences of sensed data streams from contributing to information overload while still allowing us to capitalize on the positive behavior change and self-reflection potential of this information

Going to scale with Community-Led Total Sanitation: reflections on experience, issues and ways forward

Perhaps as many as 2 billion people living in rural areas are adversely affected by open defecation (OD). Those who suffer most from lack of toilets, privacy and hygiene are women, adolescent girls, children and infants. Sanitation and hygiene in rural areas have major potential for enhancing human wellbeing and contributing to the MDGs. Approaches through hardware subsidies to individual households have been ineffective. Community-Led Total Sanitation (CLTS) is a revolutionary approach in which communities are facilitated to conduct their own appraisal and analysis of open defecation (OD) and take their own action to become ODF (open defecation-free). In six of the countries where CLTS has been spread – Bangladesh, India, Indonesia, Pakistan, Ethiopia and Kenya – approaches differ organisationally with contrasting combinations of NGOs, projects and governments. Practical elements in strategies for going to scale have included: training and facilitating; starting in favourable conditions; conducting campaigns and encouraging competition; recruiting and committing teams and full-time facilitators and trainers; organising workshops and cross-visits; supporting and sponsoring Natural Leaders and community consultants; inspiring and empowering children, youth and schools; making use of the market and promoting access to hardware; verifying and certifying ODF status; and finding and supporting champions at all levels. To spread CLTS well requires continuous learning, adaptation and innovation. It faces challenges. Paradigmatically, it requires major institutional, professional and personal shifts. Opposition at senior levels, pressures to disburse large budgets, demands to go to scale rapidly, and programmes to subsidise hardware for individual rural households, have been and remain threats and obstacles. Issues for review, reflection and research include: diversity, definition and principles; synergies with complementary approaches; scale, speed and quality; creative diversity; and physical, social and policy sustainability. In seeking constructive ways forward, four key themes or thrusts are: methodological development and action learning; creative innovation and critical awareness; learning and action alliances and networks, with fast learning across communities, districts and countries; and seeking to seed self-spreading or light touch movements. A key to good spread is finding, supporting and multiplying champions, at all levels, and then their vision, commitment and courage

A Turbine-powered UAV Controls Testbed

The latest version of the NASA Flying Controls Testbed (FLiC) integrates commercial-off-the-shelf components including airframe, autopilot, and a small turbine engine to provide a low cost experimental flight controls testbed capable of sustained speeds up to 200 mph. The series of flight tests leading up to the demonstrated performance of the vehicle in sustained, autopiloted 200 mph flight at NASA Wallops Flight Facility's UAV runway in August 2006 will be described. Earlier versions of the FLiC were based on a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate at Fort Eustis, Virginia and NASA Langley Research Center. The newer turbine powered platform (J-FLiC) builds on the successes using the relatively smaller, slower and less expensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches with the implementation of C-coded experimental controllers. Tracking video was taken during the test flights at Wallops and will be available for presentation at the conference. Analysis of flight data from both remotely piloted and autopiloted flights will be presented. Candidate experimental controllers for implementation will be discussed. It is anticipated that flight testing will resume in Spring 2007 and those results will be included, if possible

Automatic detection of one-on-one tackles and ruck events using microtechnology in rugby union

Objectives To automate the detection of ruck and tackle events in rugby union using a specifically-designed algorithm based on microsensor data. Design Cross-sectional study. Methods Elite rugby union players wore microtechnology devices (Catapult, S5) during match-play. Ruck (n = 125) and tackle (n = 125) event data was synchronised with video footage compiled from international rugby union match-play ruck and tackle events. A specifically-designed algorithm to detect ruck and tackle events was developed using a random forest classification model. This algorithm was then validated using 8 additional international match-play datasets and video footage, with each ruck and tackle manually coded and verified if the event was correctly identified by the algorithm. Results The classification algorithm’s results indicated that all rucks and tackles were correctly identified during match-play when 79.4 ± 9.2% and 81.0 ± 9.3% of the random forest decision trees agreed with the video-based determination of these events. Sub-group analyses of backs and forwards yielded similar optimal confidence percentages of 79.7% and 79.1% respectively for rucks. Sub-analysis revealed backs (85.3 ± 7.2%) produced a higher algorithm cut-off for tackles than forwards (77.7 ± 12.2%). Conclusions The specifically-designed algorithm was able to detect rucks and tackles for all positions involved. For optimal results, it is recommended that practitioners use the recommended cut-off (80%) to limit false positives for match-play and training. Although this algorithm provides an improved insight into the number and type of collisions in which rugby players engage, this algorithm does not provide impact forces of these events