9,883 research outputs found
Recommended from our members
The celestial e-sphere
The Celestial E-Sphere originally came from an idea from Dr. Bob Lambourne who expressed a desire for a Celestial Sphere that you could see from outside, rather like the desk-top spheres that you can buy. There was some discussion about the possibility of modifying the open source of Stellarium, a very popular planetarium package, but this was perceived as probably being very complex. The final impetus came when using the Sky Maps tool of the Sloan Digital Sky Survey website, shown below
Recommended from our members
3-D immersive screen experiments
We are currently piloting a range of computer simulated science experiments as 3-D virtual environments. These are rendered on a PC in 3-D and use photographs of specic parts of the actual apparatus as textures to add realism to the simulation. In particular, photographs are used to represent the consequential views of an experiment. These particular views may also be animated depending on the state of the experiment. The work combines the photographic approach of the Interactive Screen Experiments (ISEs) with the advantages of a fully simulated 3-D environment where the user can interact with the apparatus in a more natural and intuitive way. The potential advantages are that users can quickly adapt to the environment and in particular the controls. They gain realistic views of the physicality of the experiment as they are not just seeing it from a particular viewpoint, but from wherever they see t to place themselves within the experiment's scene. They are immersed in the experiment in a way that mitigates some of the objections to online as opposed to real laboratory experimentation. It is also the case that the results of an initial calibration or setup carry over into the main part of the experiment. This is perceived as an extremely important teaching element of Physics practicals as the user learns that care in setting up an experiment is an essential part of being able to get good results. Furthermore there is no need to represent scales, read-outs or controls as separate parts of the interface; these can all be rendered at their correct physical positions within the experiment. The rst of these experiments based on the use of a diffraction grating has been fully implemented and has been evaluated with a Physics A level class. The application and its evaluation will be presented. A more complicated experiment using a spectrometer has also been modelled which raises issues of complexity. These issues will also be discussed
Recommended from our members
The design of an Image Bank
Image Banks, which are collections of images with associated data and captions, are a valuable teaching tool for Astronomy courses at the Open University. Until now web pages have been created for each image and its associated information. This paper examines how a database, front-ended by a multimedia authoring tool, can provide a much more flexible and maintainable architecture for producing Image Banks. Accessibility issues are discussed
The distribution of wages and employment in rural Botswana
African Studies Center Working Paper No. 4
Toxic releases by manufacturing : world patterns and trade policies
Little evidence exists on the distribution across countries of toxic releases by manufacturing, or on how those patterns change through time. A number of studies have asked whether environmental controls imposed in the industrialized economies are diverting investments in pollution-intensive activities offshore. These studies reach a broad negative conclusion: direct investment does not appear to be stimulated by such regulation, in part because the cost of emission controls is generally a tiny fraction of operating costs. But direct investment reflects only part of what may be happening to world production patterns. Technology transfers may occur with no simultaneous direct investment, and production may readily shift toward a different global distribution without either direct investment or technology transfer. The author presents the evidence on the world distribution of manufacturing production according to pollution density - using data from the World Bank Industrial Pollution Projections Team. He then examines the validity of the claim that free trade would result in greater and more rapid environmental degradation for developing countries. He finds that: (1) The onus is on the higher-income countries to contain the emissions of their increasingly pollution-oriented mix of manufacturing industries. (2) The global trend has been toward an increasingly emission-intensive pattern of production, in relation to both manufacturing and to GDP. This trend has been remarkably constant over three decades and shows no signs of slowing. (3) The upward trend in emission-intensity of manufacturing production has been faster among lower-income nations. If pollution restraints on given industies are progressing more rapidly among the wealthier countries, this disparity would be even sharper than the Bank data suggest. Developing countries that produce coal, crude oil, or natural gas also have more pollution-intensive manufacturing sectors, based on the availability of those raw materials. It may be doubted that fostering such industries always reflects a comparative advantage. Petrochemical industries in the coal-oil-gas-producing countries are often substantially protected or subsidized. Among all developing countries, import protection stimulates a larger chemicals industry and thus more emission-intensive manufacturing. One might guess that less protection of local industrial chemical industries would decrease the pollution-intensity of the developing countries'industry. But merely relocating firms that emit globally damaging toxins clearly misses the point.Environmental Economics&Policies,Energy and Environment,Economic Theory&Research,Water and Industry,Carbon Policy and Trading
Monetary Neutrality
Prize Lecture to the memory of Alfred Nobel, December 7, 1995.Money neutrality;
Trade and the Diffusion of the Industrial Revolution
A model is proposed to describe the evolution of real GDPs in the world economy that is intended to apply to all open economies. The five parameters of the model are calibrated using the Sachs-Warner definition of openness and time-series and cross-section data on incomes and other variables from the 19th and 20th centuries. The model predicts convergence of income levels and growth rates and has strong but reasonable implications for transition dynamics.
Financial Innovation and the Control of Monetary Aggregates: Some Evidence from Canada
This paper presents an empirical test of the proposition that control of a monetary aggregate will generate a rise in its velocity.The test is carried out utilizing the Canadian experience of controlling Ml growth from 1975:3 to 1982:3. Section One of the paper presents evidence of the instability of the Canadian demand from Ml money since 1975:3. Section Two develops a specific form of the proposition which emphasizes the role of asset substitution between classes of chartered bank deposits. A relative asset demand equation is derived from a wealth maximization model subject to a technological transactions constraint and this equation is estimated from 1961 through 1982.The results lend support to the proposition that central bank control of Ml generated a rise in Ml velocity.
- …