The value of accuracy in information for planning and control

In the operation of planning and control systems we have to utilize information which in many categories possesses errors. It is important, therefore, to be able to assess the impact of inaccurate information on our plans. The author discusses some approaches to this problem when the planning system involves formulae of the management accounting type or models of the operational research variety. The value of information is clearly related to its accuracy and the most appropriate method for quantifying information value in management information systems is through Bayesian analysis and decision trees.     

A joint test for arch and bilinearity in the regression model

In this paper we argue that a simultaneous test for ARCH and bilinearity should be used to test for the possible nonlinearity of the error process in the regression model. We suggest such a joint test statistic. An empirical example shows that the individual tests of ARCH and bilinearity may not be conclusive while a joint test clearly rejects the linearity hypothesis. Our results are also applicable to pure time series models.     

Differences between previously married and never married 'gay' men: family background, childhood experiences and current attitudes

Despite a large body of literature on the development of sexual orientation, little is known about why some gay men have been (or remain) married to a woman. In the current study, a self-selected sample of 43 never married gay men ('never married') and 26 gay men who were married to a woman ('previously married') completed a self-report questionnaire. Hypotheses were based on five possible explanations for gay men's marriages: (a) differences in sexual orientation (i.e., bisexuality); (b) internalized homophobia; (c) religious intolerance; (d) confusion created because of childhood/adolescent sexual experiences; and/or (e) poor psychological adjustment. Previously married described their families' religious beliefs as more fundamentalist than never married. No differences were found between married' and never married' ratings of their sexual orientation and identity, and levels of homophobia and self-depreciation. Family adaptability and family cohesion and the degree to which respondents reported having experienced child maltreatment did not distinguish between previously married and never married. The results highlight how little is understood of the reasons why gay men marry, and the need to develop an adequate theoretical model.     

采用傅里叶变换红外光谱对原材料进行质量检测

本文介绍了带有DialPath技术的ML分析仪,用户可以快速、准确地选择恰当的较长光程以满足检测低含量分析物的需求,并可以选择一个较短光程用于液体的总鉴定。与此同时,该技术操作简单并可以快速完成检测,同在较短光程使用衰减全反射一样。     

Teaching and research in quantitative methods in university management schools

Much has been written and said about the education and development of operational researchers and management scientists from a specialist departmental viewpoint. Considerably less attention has been devoted to the role of management schools in this process and, more importantly, in their provision of a general education in quantitative methods for all their postgraduate taught course students. This paper aims to make a contribution towards rectifying this relative neglect. Moreover, it specifically contrasts the two sets of activities and argues that they are largely fulfilling different purposes and satisfying in the main different job markets. The paper also addresses some of the problems of management science researchers within a management school milieu.     

Modelling and measurement in retailing practice

The retailing sector has traditionally attracted the attention of economists and marketing specialists but only comparatively recently, at least in the UK, have management scientists become involved. Yet there is much of a measurement and modelling character in retailing to which the management scientist can contribute most usefully. This paper examines two areas of major practical importance to retailers: labour productivity, store location and size. Basic measurement and the establishment of standards can lead to considerable performance improvements in the first area. The second problem area is strategic rather than operational in essence and lends itself to either mathematical modelling or empirical techniques or to a combination of the two approaches.     

A comparison of the reliability of questionnaire versus diary data

The crucial role that communication plays in organizations has led to the development of various methodologies to collect communications data. Two of the more common techniques are one-shot questionnaires and self-recording diaries completed at the time of the interaction. Questionnaires are often viewed as unreliable since they are based on the memory and perceptions of the participants. Diaries, on the other hand, are considered to be more reliable since they are completed immediately following an interaction when the event is still fresh in the individual's mind. This paper compares the cross-recorder reliability of these two data collection instruments. A reliability measure which indicates the degree to which an individual concurs as to the occurrence of interactions across all individuals is introduced. The results, based on studies in three organizations involving 49, 61 and 110 participants respectively, indicate that diary data are significantly more reliable than data obtained from questionnaires.     

Sexual needs, control, and refusal: how "doing" class and gender influences sexual risk taking

The poor are disproportionately affected by unintended pregnancy and sexually transmitted infections (STIs). We know relatively little, however, about the sexual processes behind these disparities. Despite studies of gender enactment's influence on sexual behaviors, few analyses examine the sexual "doing" of social class. We conducted sexual history interviews with 36 women and men, half middle class and half poor and working class. Most respondents reported that men have greater sexual appetites than women, but the middle class were more likely to cite social influences while the poor and working-class respondents primarily ascribed biological origins. The social construction of sexual controllability among the middle class contributed to perceptions that sex was a containable force. Poor and working-class women described men's sexual needs as physiologically irrepressible, which shaped sexual refusal. Our findings move beyond socioeconomic status (SES) as a "risk factor" and explore two examples of how gender and social class mediate people's sexual selves and health.