31,054 research outputs found

    MAXIMUM LIKELIHOOD ESTIMATION OF A RANDOM COEFFICIENT MEAT DEMAND SYSTEM

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    The paper demonstrates that random coefficient models can be estimated by maximum likelihood if they are specified as generalized least squares models. The paper uses maximum likelihood estimation on a random-coefficient, meat-demand system. Statistical tests show that price elasticities are random, but expenditure elasticities are not. The statistical tests allow one to count the number of factors that cause randomness without requiring one to know what they are. There appear to be only two factors that make the price elasticities random.Demand and Price Analysis,

    Preliminary power train design for a state-of-the-art electric vehicle

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    Power train designs which can be implemented within the current state-of-the-art were identified by means of a review of existing electric vehicles and suitable off-the-shelf components. The affect of various motor/transmission combinations on vehicle range over the SAE J227a schedule D cycle was evaluated. The selected, state-of-the-art power train employs a dc series wound motor, SCR controller, variable speed transmission, regenerative braking, drum brakes and radial ply tires. Vehicle range over the SAE cycle can be extended by approximately 20% by the further development of separately excited, shunt wound DC motors and electrical controllers. Approaches which could improve overall power train efficiency, such as AC motor systems, are identified. However, future emphasis should remain on batteries, tires and lightweight structures if substantial range improvements are to be achieved

    Exploring the potential X-ray counterpart of the puzzling TeV gamma-ray source HESS J1507-622 with new Suzaku observations

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    The unidentified VHE (E>100 GeV) gamma-ray source HESS J1507-622 seems to not fit into standard models for sources related to young supernova remnants, pulsar wind nebulae, or young stellar populations in general. This is due to its intrinsically extended, but yet compact morphology, coupled with a relative large offset (~3.5 deg) from the Galactic plane. Therefore, it has been suggested that this object may be the first representative of a new distinct class of extended off-plane gamma-ray sources. The distance to HESS J1507-622 is the key parameter to constrain the source's most important properties, such as age and energetics of the relativistic particle population. In this article we report on results of follow-up observations of the potential X-ray counterpart with Suzaku. We present detailed measurements of its spectral parameters and find a high absorbing hydrogen column density, compatible with the total amount of Galactic gas in this direction. In comparisons to measurements and models of the Galactic three-dimensional gas distribution we show that the potential X-ray counterpart of HESS J1507-622 may be located at the far end of the Galaxy. If the gamma-ray source is indeed physically connected to this extended X-ray source, this in turn would place the object outside of the usual distribution of Galactic VHE gamma-ray emitters.Comment: 12 pages, 7 figures, accepted for publication by MNRA

    Applying and Extending the Sustainable Value Method related to Agriculture – an Overview

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    Sustainable Value is a method to measure the contribution of an economic entity, such as a farm or the entire agricultural sector, towards the sustainability (sustainable development) of a region, a country or on a global scale. A positive sustainable value is created once resources are used more efficiently than by a benchmark. It shows the excess return that is created or lost by the use of economic, environmental and social resources by an economic entity relative to a benchmark. The purpose of this paper is to give an overview on the characteristics and requirements of the SV and to provide information on (a) possible applications and (b) extensions of the SV method related to the agricultural sector. A particular emphasis is put on the choice of sustainability indicators (resource figures, welfare figure) to be included, the generic steps of SV calculation, the meaning of weighting and aggregation in the SV, the role of the Return-to-Cost Ratio in taking farm size into consideration, and the interpretation and communication of the results of an agriculture-related SV assessment. After sketching out possible extensions and variations of the SV method, the paper closes with a summary of those aspects to keep in mind when applying the SV to agriculture.sustainability contributions, value, measurement, Environmental Economics and Policy,

    Chebychev trajectory optimization program /CHEBYTOP 2/ Final report

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    Computer program for electric propelled spacecraft interplanetary, flyby, and rendezvous trajectory optimization based on Chebyshev approximation and polynomial representation

    A comparative study of nonparametric methods for pattern recognition

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    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

    Chebychev Trajectory Optimization Program /CHEBYTOP/ Final report

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    Digital computer program for interplanetary trajectory optimization and variable thrust dat

    Perceptions of IUPUI Faculty and Staff Regarding the Center for Service and Learning Faculty/Staff Development Programs

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    The purpose of this evaluation was to understand perceptions of IUPUI faculty and staff regarding the influence of the Center for Service and Learning’s (CSL) programs and resources on respondents. Specifically, the evaluation was intended to deepen CSL’s understanding of respondents’ experiences as community-engaged professionals at IUPUI. Additionally, the evaluation sought to gather input on new ideas to strengthen CSL services and programming going forward. IUPUI faculty and staff who have participated in CSL workshops, trainings, and/or requested information from CSL were emailed during the fall of 2018 and asked to participate in the Qualtrics survey. The survey was anonymous. This report shares overall findings from the survey and provides general recommendations
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