Chandra News

The Chandra Newsletter contains articles about the CXC and the Chandra mission. The Chandra Newsletter appears once a year and is edited by Paul J. Green, with editorial assistance and layout by Evan Tingle. We welcome contributions from readers. Comments on the newsletter, or corrections and additions to the hardcopy mailing list should be sent to: [email protected]

Novel Multimodal Feedback Techniques for In-Car Mid-Air Gesture Interaction

This paper presents an investigation into the effects of different feedback modalities on mid-air gesture interaction for infotainment systems in cars. Car crashes and near-crash events are most commonly caused by driver distraction. Mid-air interaction is a way of reducing driver distraction by reducing visual demand from infotainment. Despite a range of available modalities, feedback in mid-air gesture systems is generally provided through visual displays. We conducted a simulated driving study to investigate how different types of multimodal feedback can support in-air gestures. The effects of different feedback modalities on eye gaze behaviour, and the driving and gesturing tasks are considered. We found that feedback modality influenced gesturing behaviour. However, drivers corrected falsely executed gestures more often in non-visual conditions. Our findings show that non-visual feedback can reduce visual distraction significantl

Vector fields and Thurston's theory of earthquakes

This thesis consists of five chapters. The first chapter is a brief introduction to hyperbolic geometry. In the second chapter, we develop the theory of Mobius vector fields analogously to Mobius transformations. In the third, we prove an analogue of Thurston’s Earthquake Theorem for vector fields. In the fourth chapter we show how to define a measure on an earthquake vector field and conversely how to construct an earthquake vector field from a measured lamination. In the final chapter, we introduce uniformly bounded earthquake vector fields. The main results are contained in the third, fourth and fifth chapters

Spacetime Variable Superstring Vacua

In a general superstring vacuum configuration, the `internal' space (sector) varies in spacetime. When this variation is non-trivial only in two space-like dimensions, the vacuum contains static cosmic strings with finite energy per unit length and which is, up to interactions with matter, an easily computed topological invariant. The total spacetime is smooth although the `internal' space is singular at the center of each cosmic string. In a similar analysis of the Wick-rotated Euclidean model, these cosmic strings acquire expected self-interactions. Also, a possibility emerges to define a global time in order to rotate back to the Lorentzian case.Comment: 24 pages, harvmac, HUPAPP-93/

Teaching and learning history in Australian primary schools: pedagogical shifts, complexities and opportunities

From 2011 the teaching and learning of History will be expanded into all primary schools (Kindergarten – Year 6) throughout Australia under a National Curriculum, including the formal preschool/kindergarten year. History as one of four core subjects will replace current studies of society and environment curriculum taught in primary schools across. The curriculum implementation process will involve a cultural and pedagogical shift as primary teachers make adjustments to the discipline of History. This article begins with an outline of the current curriculum context. An analysis of the New South Wales Human Society and Its Environment and the Australian Curriculum: History Draft Consultation documents follows. The findings indicate that the History Draft Consultation lacks clear guidance for teachers and has a number of shortcomings compared to the NSW HSIE syllabus. There are opportunities, however, for primary teachers because of the broad similarities of content knowledge in both documents and the embedded historical concepts in the NSW syllabus document

A Tracing Method for Pricing Inter-Area Electricity Trades

In the context of liberalisation of electricity markets world wide, the need for agreed protocols for electricity trades between systems with different charges poses a special challenge. System operators need to know how much a given trade uses the network, in order to allocate an appropriate portion of their costs to that trade. This paper discusses a technique, tracing, for determining how much each of a number of trades uses different parts of the electricity network. The scheme is based on the assumption that at any network node, inflows are shared proportionally between outflows (and vice versa). The paper outlines the technique and shows how it could be applied to the problem of charging cross-border trades. The paper goes on to demonstrate that the technique has a game theoretic rationale, in that it produces the Shapley value solution to a game equivalent to this allocation problem