The politic,philosophy and practice of OR—A personal view of the issues

It is almost 50 years since Sir Henry Tizzard created the group of scientists in RAF Fighter Command who were to coin the term ‘Operational Research’. The group still exists, though its work, and the work of other defence OR groups, has changed from solving acute operational problems by the extrapolation of observed data, to an attempt at predicting the outcome of policy choices that are beyond experience. Inevitably this has forced OR further into a political arena. Yet most OR practitioners are scientists used to investigating apolitical and benign nature. In this paper the author gives a personal view of what he believes OR is trying to achieve, what practical problems and pressures have to be faced and attempts to give guidance on how to proceed.     

Racial concentration and segregation across U.S. counties, 1950–1980

By presenting race-specific population concentration indexes for U.S. counties for the 1950-1980 period, this paper updates and extends previous analyses of 1900-1974 patterns of population concentration by Duncan et al. (1961) and Vining and Strauss (1977). Declines in population concentration persisted through 1980 only among the white population. Blacks continued to experience increases in population concentration between 1970 and 1980. These racially divergent patterns of concentration in the 1970s have translated into increases in segregation between blacks and whites across U.S. counties.     

Applicability of the Social Development Model to Urban Ethnic Minority Youth: Examining the Relationship between External Constraints,Family Socialization,and Problem Behaviors

The development of preventive interventions targeting adolescent problem behaviors requires a thorough understanding of risk and protective factors for such behaviors. However, few studies examine whether different cultural and ethnic groups share these factors. This study is an attempt to fill a gap in research by examining similarities and differences in risk factors across racial and ethnic groups. The social development model has shown promise in organizing predictors of problem behaviors. This article investigates whether a version of that model can be generalized to youth in different racial and ethnic groups (N=2,055, age range from 11 to 15), including African American (n=478), Asian Pacific Islander (API) American (n=491), multiracial (n=442), and European American (n=644) youth. The results demonstrate that common risk factors can be applied to adolescents, regardless of their race and ethnicity. The findings also demonstrate that there are racial and ethnic differences in the magnitudes of relationships among factors that affect problem behaviors. Further study is warranted to develop a better understanding of these differential magnitudes.     

符号正义与公共行政 ——基于语言游戏的正义视角

公共行政是正义研究的重要领域。传统理论多采用罗尔斯、诺齐克和沃尔泽等人为正义提供的客观标准。但这些标准不仅在理论上相互冲突,而且在公共行政的实践中也常常会导致模棱两可的判断。本研究旨在提出一种符号正义的观念,来指导当代公共行政的理论与实践。这种观念认为正义并不存在中立客观的标准,而是被群体共享的信念和实践所建构。研究者只有将正义置于特定语言游戏的背景中,才能真正理解其发生和运作。因为和正义相关的不同语言游戏之间只存在家族相似性,所以公共行政必须面对相互冲突的复杂环境。符号正义的观念能够为这种公共行政问题的复杂性提供必不可少的分析框架。     

Control charts for monitoring the median in non-negative asymmetric data

Statistical Methods & Applications - Control charts are commonly used for monitoring the mean of processes. However, there are practical applications in which asymmetric data are the standard....     

Maternal and Child Anxiety: Do Attachment Beliefs or Children's Perceptions of Maternal Control Mediate Their Association?

This study tested a model of the association between maternal and child anxiety that views mother and child attachment beliefs and children's perceptions of maternal control as mediators of the association. The study was conducted with mothers and their children aged 6 to 17 (N = 88). Maternal anxiety was significantly associated with child anxiety and maternal anxious attachment beliefs, whereas child anxiety was associated with maternal anxious attachment beliefs, child insecure attachment beliefs, and children's perceptions of maternal control. Maternal anxious attachment beliefs mediated the association between maternal and child anxiety; however, child attachment beliefs and children's perceptions of maternal control did not. The influence of age and gender is also addressed. The findings are discussed in terms of elucidating the role of attachment beliefs and children's perceptions of maternal control on the association between maternal and child anxiety.     

Application of classification trees to the habitat preference of upland birds

This paper investigates the application of classification tree methodology to the bird habitat associations of the red grouse in the south Pennines of England. The effectiveness of this classification will be investigated using the kappa coefficient. Although the results for these data are disappointing, the methodology seems to have potential for this kind of problem.