Default clustering in large portfolios: Typical events

We develop a dynamic point process model of correlated default timing in a portfolio of firms, and analyze typical default profiles in the limit as the size of the pool grows. In our model, a firm defaults at a stochastic intensity that is influenced by an idiosyncratic risk process, a systematic risk process common to all firms, and past defaults. We prove a law of large numbers for the default rate in the pool, which describes the "typical" behavior of defaults.Comment: Published in at http://dx.doi.org/10.1214/12-AAP845 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Solid state laser systems for space application

Work on the development of an interferometric system for the purpose of absolute length determination commenced in January of this year. Our goal is to develop a system capable of measurements on the order of one meter with an accuracy of 1 part in 10 or greater. A modified Michelson bread board with stabilized laser diode source was assembled. Some preliminary measurements began using the tunable Santek laser in an FM modulation scheme. During this same period a literature search yielded a paper by Suematsu and Takeda which discusses a promising fourier transform technique for real time data analysis. We are in the process of evaluating this technique while we continue to change and upgrade the system configuration

Development of State of the Art Solid State Lasers for Altimetry and other LIDAR Applications

This report describes work performed and research accomplished through the end of 1997. During this time period, we have designed and fabricated two lasers for flight LIDAR applications to medium altitudes (Laser Vegetation Imaging System designs LVIS 1 and LVIS 2), designed one earth orbiting LIDAR transmitter (VCL-Alt), and continued work on a high rep-rate LIDAR laser (Raster Scanned Altimeter, RASCAL). Additionally, a 'White Paper' was prepared which evaluates the current state of the art of Nd:YAG lasers and projects efficiencies to the year 2004. This report is attached as Appendix 1 of this report

Legitimacy of the Constitutional Judge and Theories of Interpretation in the United States

The Legitimacy of the Constitutional Judge and Theories of Interpretation in the United States The paper addresses the sources of legitimacy of a judge exercising the power to declare acts of government invalid on constitutional grounds, and their relationship to theories of interpretation of the constitutional texts

Injection seeded, diode pumped regenerative ring Nd:YAG amplifier for spaceborne laser ranging technology development

A small, all solid state, regenerative ring amplifier designed as a prototype for space application is discussed. Novel features include dual side pumping of the Nd:YAG crystal and a triangular ring cavity design which minimizes the number of optical components and losses. The amplifier is relatively small (3 ns round trip time) even though standard optical elements are employed. The ring regeneratively amplifies a 100 ps single pulse by approximately 10(exp 5) at a repetition rate of 10 to 100 Hz. The amplifier is designed to be injection seeded with a pulsed, 100 ps laser diode at 1.06 microns, but another Nd:YAG laser system supplying higher pulse energies was employed for laboratory experiment. This system is a prototype laser oscillator for the Geoscience Laser Ranging System (GLRS) platform. Results on measurements of beam quality, astigmatism, and gain are given

Marshall University Music Department Presents Music from the Age of Invention, The Maelzel Woodwind Quintet, performing on historical instruments from the early 19th century, Wendell Dobbs, flute, Richard Kravchak, oboe, Richard Spece, clarinet, Stephen Lawson, horn, Kay Lawson, bassoon

https://mds.marshall.edu/music_perf/1726/thumbnail.jp

Technology education in South Africa: an evaluation of the impact of an experimental high school curriculum with particular reference to teacher pedagogy and student group work

This paper focuses on the impact of the Technology Education Project in the North West Province of South Africa (NWPTEP) which has aimed to introduce technology education into a group of the Province's high schools, in grades 10 - 12. It reports on an evaluation study carried out in the final stages of the project, looking particularly at the impact of introducing an active, learner centred, problem solving pedagogy into the schools and within this at the effect of using group work in the teaching and learning situation. The paper presents findings derived from the assessment of a pupil technological activity, an evaluation questionnaire and a set of structured interviews with those involved in the project

Efficient Dual Head Nd:YAG 100mJ Oscillator for Remote Sensing

A diode pumped, Nd:YAG laser producing 100 mJ Q-switched pulses and employing a dual-pump head scheme in an unstable resonator configuration is described. Each head contains a side pumped zig-zag slab and four 6-bar QCW 808 nm diodes arrays which are de-rated 23%. Denoting 'z' as the lasing axis, the pump directions were along the x-axis in one head and the y-axis in the other, producing a circularized thermal lens, more typical in laser rod-based cavities. The dual head design's effective thermal lens is now corrected with a proper HR mirror curvature selection. This laser has demonstrated over 100 mJ output with high optical efficiency (24%), good TEM(sub 00) beam quality, and high pointing stability