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971.
The well known birthday problem asks for the probability of at least one match out of a group of n people. Also of interest are the number of matches and the number of matched people. In this paper the means and variances of the number of matches and matched people are obtained. A generalization of the use of these methods to computer storage analysis is discussed. 相似文献
972.
《统计学通讯:模拟与计算》2013,42(4):605-618
ABSTRACT Standard statistical techniques do not provide methods for analyzing data from nonreplicated factorial experiments. Such experiments occur for several reasons. Many experimenters may prefer conducting experiments having a large number of factor levels with no replications than conducting experiments with a few factor levels with replications particularly in pilot studies. Such experiments may allow one to identify factor combinations to be used in follow-up experiments. Another possibility is when the experimenter thinks that an experiment is replicated when in fact it is not. This occurs when a naive researcher believes that sub-samples are replicates when in reality they are not. Nonreplicated two-way experiments have been extensively studied. This paper discusses the analysis of nonreplicated three-way experiments. In particular, estimation of σ2 is discussed and a test is derived for testing whether three-factor interaction is absent in sub-areas of three-way data using a nonreplicated three-way multiplicative interaction model with a single multiplicative term. Approximate null distribution of the derived test statistic is studied using Monte Carlo studies and results are illustrated through an example. 相似文献
973.
A simple approximation of the sampling distribution of least absolute residuals regression estimates
For multivariate regression with a symmetric disturbance distribution, the error in the least absolute residuals estimator is approximately multivariate normally distributed with mean zero and variance matrix λ2(X′X)?1, where X is the matrix of K explanatory variables and T observations, and λ 2/T is the variance of the median of a sample of size T from the disturbance distribution. The approximate sampling theory is validated by extensive Monte Carlo studies, and some directions of possible refinement emerge. 相似文献
974.
Experiments that involve the blending of several components are known as mixture experiments. In some mixture experiments, the response depends not only on the proportion of the mixture components, but also on the processing conditions, A new combined model is proposed which is based on Taylor series approximation and is intended to be a compromise between standard mixture models and standard response surface models. Cost and/or time constraints often limit the size of industrial experiments. With this in mind, we present a new class of designs that will accommodate the fitting of the new combined model. 相似文献
975.
吴碧霞 《淮海工学院学报(社会科学版)》2011,9(11):20-21
近年来计算机应用技术在书刊编辑中的涉及范围越来越广,然而怎样更好地将计算机技术与出版编辑工作有效地结合在一起,让两者能够运用得更加自如,是一个值得深入思考和解释的问题。结合个人多年来的实践工作经验,就计算机在书刊编辑中的运用技术展开探讨,希望能够起到抛砖引玉的作用。 相似文献
976.
Polyvinyl chloride (PVC) products are typically complex composites, whose quality characteristics vary widely depending on the types and proportions of their components, as well as other processing factors. It is often required to optimize PVC production for specific applications at the highest cost efficiency. This study describes the design and analysis of a statistical experiment to investigate the effects of different parameters over the mechanical properties of PVC intended for use in electrical wire insulation. Four commonly used mixture components, namely, virgin PVC, recycled PVC, calcium carbonate, and a plasticizer, and two process variables, type of plasticizer and filler particle size, were examined. Statistical tools were utilized to analyze and optimize the mixture while simultaneously finding the proper process parameters. The mix was optimized to achieve required strength and ductility, as per ASTM D6096 while minimizing cost. The paper demonstrates how statistical models can help tailor complex polymeric composites in the presence of variations created by process variables. 相似文献
977.
《Journal of Technology in Human Services》2013,31(1-3):51-67
Abstract Computerized spreadsheets were developed to support accounting functions, but these programs have come to have much broader applications. This chapter introduces spreadsheet analysis, briefly explains key concepts used in creating spreadsheets, and finally gives examples from direct practice and human service administration. While spreadsheets can be used for any task that requires manipulation of numbers or use of a calculator, they are most useful in producing charts and tables and for modeling problems requiring “what if” projections. 相似文献
978.
本文探讨了计算机专业开设“计算机导论”课程的必要性,分析了“计算机导论”课程的教学内容及理想的教学方式,并对授课教师提出了相关要求。 相似文献
979.
提出了一种水轮发电机组计算机监控实时仿真系统构建方案。通过对水轮发电机组及其辅助设备进行数字仿真,再结合监控层的应用软件及硬件,构成混合仿真系统,实现了计算机监控系统对水轮发电机组一系列动态过程监控的实时仿真。 相似文献
980.
在计算机科学技术的应用中常常遇到许多矛盾和问题 ,本文用辩证的方法分析了对一些问题的处理方法 ,说明辩证法在科学技术的发展中发挥了极为重要的作用 ,是人们认识世界 ,学习科学 ,改造世界的有力武器 相似文献