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91.
V. Kurotschka 《统计学通讯:理论与方法》2013,42(14):1363-1378
A complex experiment with qualirarive factors influencing the outcome of the experiment can be seen as a general ANOVA setup. A design of such an experiment will be the assignment at which of the possible levels of the factors the actual experiment should be performed. In this paper optimal designs of such experiments will be characterized with respect to three different optimality criteria including the so called uniform optimality of a design. The possible applications of the main optimization result providing these characterizations can be used to more general experiments. The particular results on these generalizations will be indicated at the end of this paper. 相似文献
92.
Composite samples are formed by physically mixing samples. Usually, composite samples are used to reduce the overall cost associated with analytical procedures that must be performed on each sample, but they can also be used to protect the privacy of individuals. Composite sampling can reduce the cost of identifying individual cases that have a certain trait, such as those with a rare disease or those exceeding pollution-level standards. Not much is lost by applying this method as long as the trait is relatively rare. Composite sampling can reduce the cost of estimating the mean of some process. When samples are composited, the ability to estimate the variance is lost. In spite of this, the potential savings are so great that composite samples have been used. Much of this paper deasl with the variance of estimators based on composite sampling when the porportions of hte original samples comprising the composite sample are actually random. Taking repeated samples and measurements on several composite samples complicates the prodcedure, but allows the estimation of between and within variation as well as measurement error. 相似文献
93.
Jehad Al-jararha 《统计学通讯:模拟与计算》2013,42(8):1906-1916
A class of sampling two units without replacement with inclusion probability proportional to size is proposed in this article. Many different well known probability proportional to size sampling designs are special cases from this class. The first and second inclusion probabilities of this class satisfy important properties and provide a non-negative variance estimator of the Horvitz and Thompson estimator for the population total. Suitable choice for the first and second inclusion probabilities from this class can be used to reduce the variance estimator of the Horvitz and Thompson estimator. Comparisons between different proportional to size sampling designs through real data and artificial examples are given. Examples show that the minimum variance of the Horvitz and Thompson estimator obtained from the proposed design is not attainable for the most cases at any of the well known designs. 相似文献
94.
The performance of step-wise group screening In terms of the expected number of runs and the expected number of incorrect decisions, Is considered. A method for obtaining optimal step-wise designs Is presented, for the cases in which the direction of each defective factor is assumed to be known a-priori and the observations are subject to error. 相似文献
95.
党的十六大以来,以胡锦涛为总书记的党中央领导集体,继续解放思想,坚持改革开放,推动科学发展,促进社会和谐,为践行人民利益观呕心沥血。"改革"作为决定当代中国命运的关键选择,成为贯穿中国特色社会主义事业始终的关键词,依然是党的十七届五中全会的核心理念。全会深入分析了今后一个时期我国经济社会发展的国内外形势,提出通过经济、政治、文化等方面的深化改革进一步实现人民经济、政治和文化利益。 相似文献
96.
Sheng-Li Zhao 《统计学通讯:理论与方法》2013,42(17):5028-5036
ABSTRACTIn this article, we consider the construction of minimum aberration 2n ? k: 2p designs with respect to some existing combined wordlength patterns, where a 2n ? k: 2p design is a blocked two-level design with n treatment factors, 2p blocks, and N = 2q runs with q = n ? k. Two methods are proposed for two situations: n ? 2q ? p ? 1 and n > N/2. These methods enable us to obtain some new minimum aberration 2n ? k: 2p designs from existing minimum aberration unblocked and blocked designs. Examples are included to illustrate the theory. 相似文献
97.
The paper aims to find variance balanced and variance partially balanced incomplete block designs when observations within blocks are autocorrelated and we call them BIBAC and PBIBAC designs. Orthogonal arrays of type I and type II when used as BIBAC designs have smaller average variance of elementary contrasts of treatment effects compared to the corresponding Balanced Incomplete Block (BIB) designs with homoscedastic, uncorrelated errors. The relative efficiency of BIB designs compared to BIBAC designs depends on the block size k and the autocorrelation ρ and is independent of the number of treatments. Further this relative efficiency increases with increasing k. Partially balanced incomplete block designs with autocorrelated errors are introduced using partially balanced incomplete block designs and orthogonal arrays of type I and type II. 相似文献
98.
In this paper, Yate's missing plot technique is used to derive the formula for substitution in a missing plot in a general incomplete block design, where blocks are assumed to be independent normal. The use of penalized normal equations, using BLUPS, makes this task simpler. 相似文献
99.
Optimality of experimental designs for spatially correlated observations is investigated.come two dimensional correlation structures are discussed and an attempt has been made to find optimal or nearly optimal design for each sitution.The solution lend to designs similar to that used for repeated measurements.The relative efficiency of the proposed designs in comparison to randomized latin square designs is tabulated for some cases. 相似文献
100.
Response surface methodology is widely used for developing, improving, and optimizing processes in various fields. In this article, we present a method for constructing three-level designs in order to explore and optimize response surfaces combining orthogonal arrays and covering arrays in a particular manner. The produced designs achieve the properties of rotatability, predictive performance and efficiency for the estimation of a second-order model. 相似文献