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181.
基于模型试验,对堆载诱发型边坡滑坡的变形机理及演化过程进行研究。研究结果表明: (1)堆载诱发型滑坡的变形演化规律可归纳为:后缘压缩阶段→蠕动变形阶段→加速滑动阶段→剧滑阶段,且剧滑启动之前的加速变形过渡时间极短;(2)利用FLAC3D软件进行堆载滑坡演化过程的动态数值分析,模拟过程中坡体应力场和位移场的演化特征表现为从上向下逐步贯通,与模型边坡破坏过程相符;(3)堆载诱发型滑坡破坏过程历时短、突发性强,在坡脚产生持续位移时即应做出滑坡预警。  相似文献   
182.
运用测量法、一维方差分析、峰度分析等方法对周口师院3年的大学新生体质测试数据进行研究,分析得出,大学新生营养不均衡现象有加重趋势,女生柔韧素质下降。阳光体育运动只是缩小了学生身体素质个体间的差异,并没有整体提升学生的体质健康水平。  相似文献   
183.
Rank tests are considered that compare t treatments in repeated measures designs. A statistic is given that contains as special cases several that have been proposed for this problem, including one that corresponds to the randomized block ANOVA statistic applied to the rank transformed data. Another statistic is proposed, having a null distribution holding under more general conditions, that is the rank transform of the Hotelling statistic for repeated measures. A statistic of this type is also given for data that are ordered categorical rather than fully rankedo Unlike the Friedman statistic, the statistics discussed in this article utilize a single ranking of the entire sample. Power calculations for an underlying normal distribution indicate that the rank transformed ANOVA test can be substantially more powerful than the Friedman test.  相似文献   
184.
In teaching the development of uniformly most powerful unbiased (UMPU) tests, one rarely discusses the performance of alternative biased tests. It is shown, through the comparison of two independent Bernoulli proportions, that a biased test (the Z test) can be more powerful than the UMPU test (Fisher's exact test—randomized) in a large region of the alternative parameter space. A more general example is also given.  相似文献   
185.
This paper presents a multivariate extension of Dunnett's test for comparing simultaneously k treatment group means with a single control group mean. A test based on Hotelling T2statistics is presented and approximate critical values are evaluated for the case of equal numbers of observations in each group, for the .05 and .01 levels of significance, for 1 to 5 variates, for 1 to 10 treatment groups, and for varying degrees of freedom. The accuracy of the procedure for generating approximate critical values is assessed via simulation studies conducted for selected cases and an example is presented using real data.  相似文献   
186.
One way to cope with high-dimensional data even in small samples is the use of pairwise distance measures—such as the Euclidean distance—between the sample vectors. This is usually done with permutation tests. Here we propose the application of exact parametric rotation tests which are no longer restricted by the finite number of possible permutations of a sample. The method is presented in the framework of the general linear model.  相似文献   
187.
The paper derives Bartlett corrections for improving the chisquare approximation to the likelihood ratio statistics in a class of location-scale family of distributions, which encompasses the elliptical family of distributions and also asymmetric distributions such as the extreme value distributions. We present, in matrix notation, a Bartlett corrected likelihood ratio statistic for testing that a subset of the nonlinear regression coefficients in this class of models equals a given vector of constants. The formulae derived are simple enough to be used analytically to obtain several Bartlett corrections in a variety of important models. We show that these formulae generalize a number of previously published results. We also present simulation results comparing the sizes and powers of the usual likelihood ratio tests and their Bartlett corrected versions when the scale parameter is considered known and when this parameter is uncorrectly specified.  相似文献   
188.
城市居民旅游感知研究,对了解和掌握当地居民对旅游发展的态度与行为意义重大,是旅游地可持续发展的必然要求。作者针对国内城市居民旅游感知进行量表开发,先查阅了大量的国内外相关学术文献,接着进行了深入的文献研究,在此基础上设计了调查问卷初稿,问卷初稿包括居民旅游经济影响感知、旅游环境影响感知、旅游社会文化影响感知、旅游发展态度和满意的总体感知、居民参与旅游发展经营管理水平感知等五个维度,每个维度包括正面影响、负面影响两个构面。随后对初试问卷进行小样本调查,根据小样本调查的数据,使用统计分析软件SPSS16.0进行数据分析,对问卷量表进行信度和效度检验,对问卷测量题项进行净化,剔除相关度较低的测量项目,最终形成正式问卷。分析结果证明,量表具有很高的信度和效度。因篇幅所限,文章只对旅游环境影响感知、旅游社会文化影响感知二个维度的净化过程进行论述。  相似文献   
189.
In this article a class of distribution-free tests for the hypothesis of no row (treatment) effect in a two-way layout design, with several observations per cell, is proposed. The tests are based on U-statistics, constructed by considering minima of all possible subsamples of same size from each cell.The proposed class of tests is compared with the parametric test, Mack and Skillings test and Yate's test for two-way layout, in terms of Pitman ARE sense. It is seen that for the case of equal number of observations per cell, the proposed tests have better efficiency for exponential and uniform error distributions.  相似文献   
190.
Likelihood ratio tests for the homogeneity of k normal means with the alternative restricted by an increasing trend are considered as well as the likelihood ratio tests of the null hypothesis that the means satisfy the trend. While the work is primarily a survey of results concerning the power functions of these tests, the extensions of some results to the case of not necessarily equal sample sizes are presented. For the case of known or unknown population variances, exact expressions are given for the power functions for k=3,4, and approximations are discussed for larger k. The topics of consistency, bias and monotonicity of the power functions are included. Also, Bartholomew's conjectures concerning minimal and maximal powers are investigated, with results of a new numerical study given.  相似文献   
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