Young Supernova Remnants in the Magellanic Clouds

There are a half-dozen or so young supernova remnants in the Magellanic Clouds that display one or more of the following characteristics: high velocity (>1000 km/s) emission, enhanced metallicity, or a rapidly rotating pulsar. I summarize the current state of knowledge of these remnants and present some recent results mostly from the new X-ray astronomy satellites.Comment: 10 pages, including 8 postscript figs, LaTeX. To appear in the Proceedings of the 11th Annual October Maryland Astrophysics Conference ``Young Supernova Remnants'

Controlled cavity-QED using a photonic crystal waveguide-cavity system

We introduce a photonic crystal waveguide-cavity system for controlling single photon cavity-QED processes. Exploiting Bloch mode analysis, and medium-dependent Green function techniques, we demonstrate that the propagation of single photons can be accurately described analytically, for integrated periodic waveguides with little more than four unit cells, including an output coupler. We verify our analytical approach by comparing to rigorous numerical calculations for a range of photonic crystal waveguide lengths. This allows one to nano-engineer various regimes of cavity-QED with unprecedented control. We demonstrate Purcell factors of greater than 1000 and on-chip single photon beta factors of about 80% efficiency. Both weak and strong coupling regimes are investigated, and the important role of waveguide length on the output emission spectra is shown, for vertically emitted emission and output waveguide emission

Measuring efficiency when market prices are subject to adverse selection

In perfectly competitive markets, prices aggregate inputs and outputs into a money metric that allows production plans to be ranked by their profitability. When informational asymmetries in competitive markets lead to adverse selection, prices in these markets assume an additional role that conveys information about product quality. In the case of banking production, quality is linked to risk because prices are linked to credit quality. ; The problem of efficiency measurement is complicated by the additional role because quality varies with price and price is a decision variable of firms operating in these markets. The effect of these endogenous components of prices on financial performance is illustrated with a production-based model and a market-value model that generate "best- practice" frontiers. Unlike the standard profit function's frontier, these frontiers are not conditioned on prices so that they compare the financial performance of firms with different quality-linked prices. Hence, they identify the most efficient pricing strategies as well as the most efficient production plans. ; These two alternative models for measuring efficiency are employed to study the efficiency of highest level bank holding companies in the United States in 1994. The contractural interest rates these banks obtain on their loans and other assets are shown to influence their expected profit, profit risk, market value, and efficiency.Banks and banking - Costs

Space structure vibration modes: How many exist? Which ones are important?

This report attempts to shed some light on the two issues raised in the title, namely, how many vibration modes does a real structure have, and which of these modes are important? The surprise-free answers to these two questions are, respectively, an infinite number and the first several modes. The author argues that the absurd subspace (all but the first billion modes) is not a strength of continuum modeling, but, in fact, a weakness. Partial differential equations are not real structures, only mathematical models. This note also explains (1) that the PDE model and the finite element model are, in fact, the same model, the latter being a numerical method for dealing with the former, (2) that modes may be selected on dynamical grounds other than frequency alone, and (3) that long slender rods are useful as primitive cases but dangerous to extrapolate from

What are the costs of procurement and who bears them?

The costs of procurement are transaction costs which are separate from the direct costs of a project. In this paper discussion is concentrated on costs of tendering. Types of cost, including money costs and opportunity costs, short-term and long-term costs, private and social costs are defined and examined in relation to various types of product and methods of procurement. The costs of the contractor and of the client are considered and tentative conclusions drawn as to who bears these costs in the short-run and in the long run. They may fall on the parties to the process for the particular project, on other contractors and clients or on society as a whole