Decomposition Algorithms for Stochastic Programming on a Computational Grid

We describe algorithms for two-stage stochastic linear programming with recourse and their implementation on a grid computing platform. In particular, we examine serial and asynchronous versions of the L-shaped method and a trust-region method. The parallel platform of choice is the dynamic, heterogeneous, opportunistic platform provided by the Condor system. The algorithms are of master-worker type (with the workers being used to solve second-stage problems, and the MW runtime support library (which supports master-worker computations) is key to the implementation. Computational results are presented on large sample average approximations of problems from the literature.Comment: 44 page

Thermal (Silicon Diode) Data Acquisition Systems

Marshall Space Flight Center s X-ray Cryogenic Facility (XRCF) has been performing cryogenic testing to 20 Kelvin since 1999. Two configurations for acquiring data from silicon diode temperature sensors have been implemented at the facility. The facility's environment is recorded via a data acquisition system capable of reading up to 60 silicon diodes. Test article temperature is recorded by a second data acquisition system capable of reading 150+ silicon diodes. The specifications and architecture of both systems will be presented

Validating Sample Average Approximation Solutions with Negatively Dependent Batches

Sample-average approximations (SAA) are a practical means of finding approximate solutions of stochastic programming problems involving an extremely large (or infinite) number of scenarios. SAA can also be used to find estimates of a lower bound on the optimal objective value of the true problem which, when coupled with an upper bound, provides confidence intervals for the true optimal objective value and valuable information about the quality of the approximate solutions. Specifically, the lower bound can be estimated by solving multiple SAA problems (each obtained using a particular sampling method) and averaging the obtained objective values. State-of-the-art methods for lower-bound estimation generate batches of scenarios for the SAA problems independently. In this paper, we describe sampling methods that produce negatively dependent batches, thus reducing the variance of the sample-averaged lower bound estimator and increasing its usefulness in defining a confidence interval for the optimal objective value. We provide conditions under which the new sampling methods can reduce the variance of the lower bound estimator, and present computational results to verify that our scheme can reduce the variance significantly, by comparison with the traditional Latin hypercube approach

Producing Textbook Sociology

The conservative role of the textbook in reproducing the dominant ideas of a disciplinary field is well known. The factors driving that content have remained almost entirely unexamined. Reviewing the universe of textbooks aimed at the American market between 1998 and 2004, we explore the persistence of the identification in American sociology textbooks of a paradigm in which structural functionalism, conflict theory, and symbolic interactionism are used to frame the theoretical core of the discipline. We examine how over time the textbook market produces both supply and demand pressures to reproduce content that is at odds with the mainstream of the profession. We draw upon in-depth interviews with recent textbook authors and their editors

Poster - Private Pete Fights Illiteracy at Fort Ontario: The Men it Changed

A poster created by history students of Morehead State University for display at Fort Ontario Historic Site in March of 2023.https://scholarworks.moreheadstate.edu/stu_1210th_fort_ontario/1099/thumbnail.jp

Poster - Private Pete Fights Illiteracy at Fort Ontario: The Men in Charge

A poster created by history students from Morehead State University for display at Fort Ontario Historic Site in March of 2023.https://scholarworks.moreheadstate.edu/stu_1210th_fort_ontario/1097/thumbnail.jp

Poster - Private Pete Fights Illiteracy at Fort Ontario: The 1210 Special Training Service Unit

A poster created by history students from Morehead State University for display at Fort Ontario Historic Site in March of 2023.https://scholarworks.moreheadstate.edu/stu_1210th_fort_ontario/1098/thumbnail.jp