A survey of nested designs

A nest with parameters (r,k,λ)→(r′,k′,λ′) is a BIBD on (b,v,r,k,λ) where each block has a distinguished sublock of cardinality k, the sublocks forming a (b,v,r,k,λ)-design.These designs are ‘nested’ in the sense of W.T. Federer (1972), who recommended the use of these designs for the sequential addition of periods in marketing experiments in order to retain Youden design properties as rows are added. Note that for a Youden design, the b columns and v treatments are in an SBIBD arrangement with parameters v=b, k=r, and λ.     

Statistics Problems with Simple Numbers

This article concerns the construction of simple numerical illustrations of statistical techniques for use in introductory classes. Minimizing the amount of calculation facilitates checking, promotes reliability, is quicker, and reinforces the confidence of the student. Methods are described for generating (a) samples of size 3 upwards with integer-valued means and standard deviations, and (b) simple linear regressions with integer-valued intercepts and integer-valued or simple fractional slopes. Extensions to give exact pooled standard deviations in the two-sample problem and simple exact fractional correlation coefficients are also indicated. Further statistical procedures amenable to the same general approach are listed.     

论民族主义史学的兴起与缺失(下)--从全球比较史学的角度考察

民族主义史学是近现代史学的主要潮流。自 17世纪从西方兴起以后 ,随着西方殖民主义的扩张而走向全球 ,至今不衰。对于非西方地区的史家而言 ,民族主义史学为他们抵御西方军事和文化的侵略 ,从事民族国家的建设 ,起了重要的作用。尽管如此 ,民族主义本身是西方历史与文化的产物 ,并不完全适用于解释中国和印度等地区的历史。因此 ,需要从比较史学的角度 ,以西方、东亚、伊斯兰和印度等地民族主义史学的发展特点为例 ,分析民族主义史学的共性 ,及其在近年所面临的挑战 ,以展望全球史学在未来的发展走向     

The joint paediatric–forensic examination in child abuse

The investigation of alleged child abuse should be multi-professional and coordinated to minimize distress to the child and family. Much attention has focused on the joint interview process, with less prominence being given to the medical component of the initial investigation. No standard practice exists in the United Kingdom regarding the conduct of the medical examination or in the training requirements of the doctors who perform the examination. We present a model of practice which has evolved in Edinburgh and the Lothians, drawing on the combined expertise and experience of paediatricians and police surgeons, which has operated for over 2 years; and propose a formal accreditation process for doctors who wish to specialize in the field of child abuse. © 1998 John Wiley & Sons, Ltd.     

Managing Corporate Knowledge Experiences with SODA and V·I·S·A

It is often said that success in today's competitive environment depends on the acquisition and application of sound, relevant knowledge. This paper introduces two management science approaches that have been used for the effective management of knowledge, towards the development of strategy, planning and decision making, in a wide range of organizational settings. Both approaches make use of computer technology to provide a flexible and interactive environment incorporating a visual representation of the problem. The paper briefly describes each approach, together with a case study illustrating its use in practice. A number of common themes relevant to the management of knowledge are identified and discussed. The themes highlight the benefits which arise through the use of computer technology alongside a number of issues relevant to the management of the group process.     

Familial spinal shape

It has been proposed that there is a familial relationship in the shape of the spine. This paper describes a pilot study investigating familial shape in the sagittal plane (side view), using three data sets of normal Leeds schoolchildren. The study is exploratory in nature, because only small samples were available. Data acquisition was by means of the Quantec system, which obtains surface shape measurements and extracts a line representing the spinal curve. The coordinates of the spine line in the sagittal plane are then used to investigate familial correlations of spinal shape. The spine lines first undergo some preprocessing, including Procrustes rotations to remove location, rotation and size effects. Smoothed principal component analysis of the curves provides suitable shape variables, and familial correlations between curves are then investigated. The covariates of sex and height are also investigated in the analysis. It does appear that there could be some evidence for familial correlations in sagittal spinal shape, although a further large-scale study is required. Finally, a discussion of the approach and other alternatives is considered.     

Social energy and racial segregation in the university context

Objectives: Universities often promote their diversity as a selling point, but are students of different races at these universities integrated socially? Using theories on social energy, I examine racial segregation among university students. Methods: Quantitative data were collected on student residence patterns and social groupings formed at lunch tables at a case study university. In addition, interviews were conducted with 25 students. Results: Students are substantially more segregated than chance predicts. Blacks and Hispanics are particularly segregated. Interviews reveal that these students spend large amounts of social energy coping with prejudice and discrimination as well as functioning in a student culture they find unwelcoming and foreign. Conclusions: Social energy drains on minority students from discrimination and an unwelcoming campus culture reduce energy left for interracial interaction, making these racial groups more segregated. The study highlights the need for understanding segregation as a function of the interaction of out-group preferences, in-group preferences, and the larger social context.