Random distances and edge correction

Two classes of random distances (generated as contact distances or free path lengths) external to a stationary random closed set in Euclidean space are introduced. The censored distance distributions within bounded region are obtained. Unbiased estimators of the random distance distribution functions using only the information from inside the bounded region are constructed.     

Robust tests for equality of two population means under the normal model

A robust procedure is developed for testing the equality of means in the two sample normal model. This is based on the weighted likelihood estimators of Basu et al. (1993). When the normal model is true the tests proposed have the same asymptotic power as the two sample Student's t-statistic in the equal variance case. However, when the normality assumptions are only approximately true the proposed tests can be substantially more powerful than the classical tests. In a Monte Carlo study for the equal variance case under various outlier models the proposed test using Hellinger distance based weighted likelihood estimator compared favorably with the classical test as well as the robust test proposed by Tiku (1980).     

Numerical algorithms for solving nonlinear L р-norm estimation problems: part II - a mixture method for large residual and illo-conditioned problems

The nonlinear least squares algorithm of Gill and Murray (1978) is extended and modified to solve nonlinear L _р-norm estimation problems efficiently. The new algorithm uses a mixture of 1st-order derivative (Guass-Newton) and 2nd-order derivative (Newton) search directions. A new rule for selecting the “grade” r of the p-jacobiab matrix J_p was also incorporated. This brought about rapid convergence of the algorithm on previously reported test examples.     

Using an approximate L1 Estimator

This note investigates the efficiency of using near-best or approximate L₁ estimators as starting values in L₁ linear programming procedures. In particular, it is shown that the total computer time can often be reduced if one first computes the least squares estimator, β, and then adjust y to y - Xβ in Barrodale and Roberts’ improved algorithm.     

An algorithm for computing nonparametric estimators of change‐points

An efficient FORTRAN subroutine for computing three nonparametric point estimators of change-points is offered. Estimates computed from the subroutine are obtained for two classical data sets     

On estimating the mean of the selected population with unknown variance

This paper compares four estimators of the mean of the selected population from two normal populations with unknown means and common but unknown variance. The selection procedure is that the population yielding the largest sample mean is selected. The four estimators considered are invariant under both location and scale transformations. The bias and mean square errors of the four estimators are computed and compared. The conclusions are close to those reported by Dahiya ‘1974’, even for small sample sizes     

An empirical bayes approach to estimating the probability of correct selection

In the problem of selecting the best of k populations, Olkin, Sobel, and Tong (1976) have introduced the idea of estimating the probability of correct selection. In an attempt to improve on their estimator we consider anempirical Bayes approach. We compare the two estimators via analytic results and a simulation study.     

Statistical Reversion toward the Mean: More Universal than Regression toward the Mean

Schmittlein discussed the lack of universality of regression toward the mean. The present note emphasizes the universality of a similar effect, dubbed “reversion” toward the mean, defined as the shift in conditional expectation of the upper or lower portion of a distribution. Reversion toward the mean is a useful concept for statistical reasoning in applications and is more self-evidently plausible than regression toward the mean.     

从康德到鲍德里亚——基于“审美距离”的多维解读

距离概念的提出源于对文本的纯审美关注,古典主义美学家康德的"审美无功利"命题为其提供了理论支撑.在现代文学批评中,审美距离理论主要强调主体与文本的一种认知距离.当下文化研究的异军突起,使得对审美距离的阐释不再立足于审美心理与文本接受层面,而是体现为现代个体及其艺术对外在物化现实的审美超越上.在不同的阐释语境中,距离体现并表征着不同的审美文化形态和逻辑.     

Business Education: Real Time or Semester Time?

Both the context and content of management education are changing as new providers compete for market share. As education goes increasingly online and offcampus, many traditional universities will feel the effects of consolidation within their own ranks. Business schools will face additional pressure as corporate universities and Internet universities offer an economical and effective means of professional education. Unless MBA programs seize opportunities for creative collaboration, today’s potential partners will become tomorrow’s predators. This revised version was published online in July 2006 with corrections to the Cover Date.