法向表面力形式的热驱动力

本文对热驱动力的法向表面力形式及其在流动中起作用的条件作了分析,对这种热驱动流问题作了界定.利用热驱动力的概念对几种受热过程影响的流动作了定性的讨论.对热阻力及其与热驱动力的关系作了阐述.     

多维最大值吸引场中分布函数的尾等价问题

本文将[3」中对一维情况的分布函数的尾等价定义推广到多维情况,得到两个多维尾等价的分布函数属于同一最大值吸引场的结论。     

Characterizations of geometric distribution and discrete IFR (DFR) distributions using order statistics

Let X be a discrete random variable the set of possible values (finite or infinite) of which can be arranged as an increasing sequence of real numbers a₁<a₂<a₃<…. In particular, a_i could be equal to i for all i. Let X_1n≦X_2n≦?≦X_nn denote the order statistics in a random sample of size n drawn from the distribution of X, where n is a fixed integer ≧2. Then, we show that for some arbitrary fixed k(2≦k≦n), independence of the event {X_kn=X_1n} and X_1n is equivalent to X being either degenerate or geometric. We also show that the montonicity in i of P{X_kn = X_1n | X_1n = a_i} is equivalent to X having the IFR (DFR) property. Let a_i = i and $\text{G(i) = P(X≧i), i = 1, 2, …}$. We prove that the independence of {X_2n ? X_1n ∈B} and X_1n for all i is equivalent to X being geometric, where B = {m} (B = {m,m+1,…}), provided G(i) = q^i?1, 1≦i≦m+2 (1≦i≦m+1), where 0<q<1.     

On uniform approximation of Poisson variates by normal ones

In this paper the accuracy of the normal approximation to the Poisson is treated from the viewpoint of direct approximation of Poisson variables by normal ones. The conclusions that are derived on the accuracy of this approximation lead (among others) to very useful results on confidence limits for the mean of a linear combination of independent Poisson variables; these latter are employed in precise determination of the composition of a mixture of radioactive isotopes by means of a scintillation counter.     

系动词在科技英语中的量化分析

本文对系动词进行定性分析和量化分析.作者运用统计软件SPSS和编程语言SNOBL4对科技英语数据库--T4中的系动词进行量化分析,从中获得的数据与系动词在其它三个数据库--LOBA和BROWNA(新闻英语数据库),MTE(法律英语数据库)中的相关数据进行比较,总结了系动词在科技英语中的用法和分布特点.     

Robustness of the linear discriminant function to nonnormality: Johnson's system

The asymptotic distribution of the Errors of Misclassification in using the Linear Discriminant Function is investigated here. The purpose is to study the effects of nonnormality on these errors. The class of distributions considered is the Johnson's system. Each of the three random variables can be transformed to normality. In one particular case numerical evaluations are made, based on which it is possible to recommend whether or not it is necessary to make the transformation prior to classification. In a parallel study, we present similar results for the Edgeworth Series distribution, where the random variables cannot be transformed to normality.     

综合性大学发展师范教育的困境及其解决途径

20世纪90年代以来出现了高校合并的浪潮,在此次浪潮的影响下,各综合性大学纷纷建立教育学院、师范学院、教育系或开设教育类课程,承担起为中等教育培养师资的重任,为师范教育的发展带来了良好的机遇。但是,在综合性大学开展师范教育也存在着管理体制不完善、师资力量不足、培养目标不明确、课程设置僵化等缺陷,要从根本上解决这些问题,加强综合性大学中师范教育的“师范性”,就必须在推进制度化建设、优化教师队伍、促进师范专业学科建设、创新培养模式、开设校本化课程等方面下功夫,以适应高教改革,推动师范教育的发展。     

川东师范学堂与西南师范学院的组建

为实施新学制,培养师资,光绪三十二年(1906年)重庆创办了第一所正规的师范学校--官立川东师范学堂.民国建立后,该学堂改名为川东师范学校.1932年,该校设立乡村师范专修科.次年,专修科迁至沙坪坝磁器口,并先后改名为乡村建设学院、四川省立教育学院.1950年,四川省立教育学院与1940年创办的国立女子师范学院合并组建西南师范学院.1985年,西南师范学院更名为西南师范大学.     

LOGISTIC REGRESSION COMPARED TO NORMAL DISCRIMINATION FOR NON-NORMAL POPULATIONS'

An investigation is undertaken of the logistic regression procedure for estimating the posterior probability of an object belonging to one of two populations. The asymptotic bias and mean square error associated with the procedure are derived for univariate populations whose distributions satisfy the general Day-Kerridge model for which the logistic form is valid for the posterior probability. These properties are compared with those of the normal discrimination method based on the classical assumption of normal populations with common variances. The asymptotic relative efficiency of logistic regression is considered on the basis of asymptotic mean square error.     

A formula for P(bi≤Ri≤ai, 1≤i≤m) under a general class of alternatives

Let X_i≤?≤X_m and Y_i≤?≤Y_n be two sets of independent order statistics from continous distributions with distribution functions F and G respectively. Let R_i denote the rank of X_i in the combined order sample. Steck (1980) has found an expression for P(b_i≤R_i≤a_i, all i) when F = h(G), h being the incomplete beta function with parameters (α,β?α+1). An alternative expression for the same probability is obtained which is computationally a substantial improvement on Steck's result.