33,797 research outputs found
A Vision for and Brief History of Youth Philanthropy
AFP offers this report as both an evaluation and marker of the state of the youth philanthropy field and as a record of the Youth in Philanthropy Summit -- its proceedings, outcomes and next steps. Significant progress was achieved; partnerships were forged; a future was envisioned; and each of the participants agreed to ownership of results. The Summit provided direction for what needs to happen for youth philanthropy to become both recognized as a movement and fully integrated into the national and international consciousness.This document has three primary purposes: to offer information on youth philanthropy, its origins and history; to present the development of the Summit; and to document the key themes and outcomes
Single Charged MSSM Higgs-boson production at a Linear Collider
In the Minimal Supersymmetric Standard Model we present the calculation of
the single charged Higgs-boson production in the gamma W- or Z W-fusion and the
charged Higgs strahlung channel, e^+ e^- -> e nu H^\pm. The set of all O(alpha)
corrections arising from loops of Standard Model fermions and scalar fermions
are taken into account. Contrary to the case of single neutral heavy CP-even
Higgs-boson production, for the charged Higgs boson we find for all the
parameter space of the typical benchmark scenarios a cross section smaller than
\sim 0.01 fb for sqrt(s)/2 \lessim M_H^\pm.Comment: 4 pages, 2 figure
Compression failure mechanisms in unidirectional composites
Compression failure mechanisms in unidirectional composites were examined. Possible failure modes of constituent materials are summarized and analytical models for fiber microbuckling are reviewed from a unified viewpoint. Due to deficiencies in available models, a failure model based on nonlinear properties and initial fiber curvature is proposed. The effect of constituent properties on composite compression behavior was experimentally investigated using two different graphite fibers and four different epoxy resins. The predominant microscopic scale failure mode was found to be shear crippling. In a soft resin, shear crippling was in the form of buckling of fibers on a microscopic scale. However, stiff resins failure was characterized by the formation of a kink band. For unidirectional laminates, compressive strength, and compressive modulus to a less extent, were found to increase with increasing magnitude of resin modulus. The change in compressive strength with resin modulus was predicted using the proposed nonlinear model
A comparative study of nonparametric methods for pattern recognition
The applied research discussed in this report determines and compares the correct classification percentage of the nonparametric sign test, Wilcoxon's signed rank test, and K-class classifier with the performance of the Bayes classifier. The performance is determined for data which have Gaussian, Laplacian and Rayleigh probability density functions. The correct classification percentage is shown graphically for differences in modes and/or means of the probability density functions for four, eight and sixteen samples. The K-class classifier performed very well with respect to the other classifiers used. Since the K-class classifier is a nonparametric technique, it usually performed better than the Bayes classifier which assumes the data to be Gaussian even though it may not be. The K-class classifier has the advantage over the Bayes in that it works well with non-Gaussian data without having to determine the probability density function of the data. It should be noted that the data in this experiment was always unimodal
Levels or Differences in Meat Demand Specification
We estimated a wholesale demand system for beef, pork, lamb, chicken, and turkey using quarterly U.S. data and a dynamic, CBS system (Keller and Van Driel). The CBS system is a differential system, which means that it might be more appropriately applied in those situations where the data have unit roots. If there are unit roots, differencing the data can improve the properties of the estimates. If the data do not have unit roots, differencing the data might harm the properties of the estimates. We tested the specification of the model's error terms using state-space techniques. State-space units allow one to deal with roots on the unit circle without filtering the data (See Durbin and Koopman). The demand system has only four independent error terms. The state-space model we used could have decomposed these four independent error terms into four errors with unit roots and four with 0 roots. Adding state-space features to the model greatly improved its performance as measured by the likelihood ratio statistics. The estimates imply that the raw demand data have two unit roots and three 0 roots. Our mixed approach improves the properties of the estimates.Demand and Price Analysis,
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