6,954 research outputs found
Generalised action-angle coordinates defined on island chains
Straight-field-line coordinates are very useful for representing magnetic
fields in toroidally confined plasmas, but fundamental problems arise regarding
their definition in 3-D geometries because of the formation of islands and
chaotic field regions, ie non-integrability. In Hamiltonian dynamical systems
terms these coordinates are a form of action-angle variables, which are
normally defined only for integrable systems. In order to describe 3-D magnetic
field systems, a generalisation of this concept was proposed recently by the
present authors that unified the concepts of ghost surfaces and
quadratic-flux-minimising (QFMin) surfaces. This was based on a simple
canonical transformation generated by a change of variable , where and are poloidal and toroidal
angles, respectively, with a new poloidal angle chosen to give
pseudo-orbits that are a) straight when plotted in the plane and
b) QFMin pseudo-orbits in the transformed coordinate. These two requirements
ensure that the pseudo-orbits are also c) ghost pseudo-orbits. In the present
paper, it is demonstrated that these requirements do not \emph{uniquely}
specify the transformation owing to a relabelling symmetry. A variational
method of solution that removes this lack of uniqueness is proposed.Comment: 10 pages. Accepted by Plasma Physics and Controlled Fusion as part of
a cluster of refereed papers in a special issue containing papers arising
from the Joint International Stellarator & Heliotron Workshop and
Asia-Pacific Plasma Theory Conference, held in Canberra and Murramarang
Resort, Australia, 30 January - 3 February, 201
myTea: Connecting the Web to Digital Science on the Desktop
Bioinformaticians regularly access the hundreds of databases and tools that are available to them on the Web. None of these tools communicate with each other, causing the scientist to copy results manually from a Web site into a spreadsheet or word processor. myGrids' Taverna has made it possible to create templates (workflows) that automatically run searches using these databases and tools, cutting down what previously took days of work into hours, and enabling the automated capture of experimental details. What is still missing in the capture process, however, is the details of work done on that material once it moves from the Web to the desktop: if a scientist runs a process on some data, there is nothing to record why that action was taken; it is likewise not easy to publish a record of this process back to the community on the Web. In this paper, we present a novel interaction framework, built on Semantic Web technologies, and grounded in usability design practice, in particular the Making Tea method. Through this work, we introduce a new model of practice designed specifically to (1) support the scientists' interactions with data from the Web to the desktop, (2) provide automatic annotation of process to capture what has previously been lost and (3) associate provenance services automatically with that data in order to enable meaningful interrogation of the process and controlled sharing of the results
An Economic Assessment of the Costs and Benefits of Natura 2000 Sites in Scotland
In accordance with the European Commission "Habitats Directive" (Directive 92/43/EEC) and the "Birds Directive" (Directive 79/409/EEC), Scotland must contribute to the development of a UK network of protected areas that represent the most important wildlife sites in the European Union, known as the Natura 2000 (N2K) network. This network is made up of Special Protection Areas (SPAs) classified under the Birds Directive and of Special Areas of Conservation (SACs) under the Habitats Directive. In Scotland, by 31/12/02, 355 N2K sites had been identified, comprising 223 candidate SACs (cSACs) and 132 SPAs, accounting for 9.3% of Scotland's land surface. As 55 sites are both cSACs and SPAs, there are actually 300 separate individual N2K sites
Think aloud, non-continuous reporting, and annotated cloze: using verbal report and a self-coding procedure in looking at German and Japanese informants' processing of a second language cloze task
Development of corporate accounting in Australia
Corporate accounting in Australia can be said to have passed through four phases. The initial phase involved the introduction of minimum standards of statutory disclosure. The second phase was largely an extension of these statutory requirements to include income statements and consolidated statements. This was followed by the activities of the accounting profession, stock exchanges and others to improve the details of disclosure
Field Playback of Male Display Attracts Females in Lek Breeding Sage Grouse
Recent correlational studies of lekking sage grouse suggest that male vocal display attracts females. To test this hypothesis further, the natural displays of a territorial male were supplemented with the tape-recorded display of another reproductively successful individual. Significantly, more females approached the speaker\u27s location on days when the recording was played, and also on nonplayback days immediately following a playback, than on other nonplayback days. Analysis of male displays indicated that females were responding to the playback itself rather than to changes in male behavior. The after-response following a playback suggests that some females present during a playback remembered its location and approached on a subsequent lek visit. The results provide necessary support for the epigamic function of vocal display, and suggest ways in which female responses to male display may influence lek structure
Episodes in the Australian tax accounting saga
Tax effect accounting was introduced into Australia a little over a decade ago. The treatment of the tax effect of losses carried forward and the trading stock valuation adjustment introduced further complications to this new aspect of corporate accounting and reporting. This paper presents an account of the resolution of these accounting issues. It covers the role of professional bodies, companies, and regulatory authorities and the conflicts which arose among them
Edward Stamp: The Australian connection
There could be little dispute about the fact that the late Edward Stamp was inextricably involved with events surrounding the formation of the Accounting Standards Board as it came to be called in the United Kingdom. However, the power of his influence and the background driving his activities are matters of contention. This note suggests that commentators, while focusing on the United Kingdom, may have overlooked an important factor in the Australian connection
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