Monitoring Variation in a Multivariate Process When the Dimension is Large Relative to the Sample Size

A control procedure is presented for monitoring changes in variation for a multivariate normal process in a Phase II operation where the subgroup size, m, is less than p, the number of variates. The methodology is based on a form of Wilk' statistic, which can be expressed as a function of the ratio of the determinants of two separate estimates of the covariance matrix. One estimate is based on the historical data set from Phase I and the other is based on an augmented data set including new data obtained in Phase II. The proposed statistic is shown to be distributed as the product of independent beta distributions that can be approximated using either a chi-square or F-distribution. An ARL study of the statistic is presented for a range of conditions for the population covariance matrix. Cases are considered where a p-variate process is being monitored using a sample of m observations per subgroup and m < p. Data from an industrial multivariate process is used to illustrate the proposed technique.     

Career Research From an Action Perspective: The Self-Confrontation Procedure

A videotape playback procedure (self-confrontation) following a career-related conversation is proposed as a means of studying career development from an action perspective. This perspective is premised on an understanding of career development as intentional, goal-directed, and occurring in a social context. In this article, a career conversation between a parent and an adolescent is used to illustrate the procedure. During the individual playback, the participants are asked for their thoughts and feelings (cognitions) while the conversation took place, and their interpretation of it. The categories used in the analysis are described. This procedure provides contextually-sensitive and empirically-grounded data useful for researchers and practitioners.     

The development and disturbance of emotions: An application of self psychology to clinical work with children

This article applies self psychology, as developed by Heinz Kohut, to clinical work with children. It begins with a brief summary of self psychology as a theoretical framework, focusing on the role of selfobjects in the development of the self. Then, the role of selfobjects in the development and disturbance of emotions is discussed. The paper concludes by describing the treatment implications of the self psychological perspective for clinical work with children, illustrating them through three case vignettes, and identifying certain questions for further inquiry.     

Ego Psychology and Self Psychology in social work practice

Ego Psychology and Self Psychology are compared by examining how each theory would imply different treatment techniques. These differences are discussed at both a theoretical level and in terms of their applications to the same case. At the level of theory, Mahler's and Kohut's views are compared along five dimensions: definition of the problem, motivation, conflict, the nature of the therapeutic process, and the therapist's role in that process. At the level of technique, specific attention is paid to when the differences aid or impede the therapeutic process.     

Non-profit institutions in an input-output framework

This paper discusses the conceptual treatment of non-profit institutions in the US input-output (I-O) accounts prepared by the Bureau of Economic Analysis, describes the sources and methods used to identify and measure the output of non-profits by I-O industry, and analyses the published benchmark I-O data for 1982 identifying output attributable to non-profits. In the context of the I-O framework, which is detailed and comprehensive, some conceptual and statistical questions associated with the treatment of non-profits are identified and discussed. These issues of definition, scope and measurement are particularly pertinent in light of the recommendations in the 1993 international System of National Accounts on sectoring and on presentation of flows.The author wishes to acknowledge the helpful comments of colleagues at the Bureau of Economic Analysis and other participants in the Workshop, as well as those of two anonymous reviewers. The views expressed in this paper are those of the author's own. They do not necessarily represent the views of the Bureau of Economic Analysis and the US Department of Commerce.     

Migration and mortality: the experience of birthplace groups in Australia

"Wide diversity exists in the mortality experience of different birthplace groups in Australia, and this also occurs with respect to their cause of death profiles. Most migrant groups experience lower mortality in Australia than in their country of origin, and most experience lower mortality than the Australian-born population. In the latter case the main [groups] are the Scots, Irish, Poles, South Pacific Islanders, Scandinavian men and North American women. Exceptionally high levels of survival occur among Greeks and Italians in Australia. The lower risk of mortality from heart disease is a principal reason for the deficit between observed and expected deaths of most migrant groups in Australia." The analysis is based on deaths of those aged 15-74 by birthplace, as recorded by the Australian Bureau of Statistics in the years 1980, 1981, and 1982.     

Strong approximations for time-varying infinite-server queues with non-renewal arrival and service processes

In real stochastic systems, the arrival and service processes may not be renewal processes. For example, in many telecommunication systems such as internet traffic where data traffic is bursty, the sequence of inter-arrival times and service times are often correlated and dependent. One way to model this non-renewal behavior is to use Markovian Arrival Processes (MAPs) and Markovian Service Processes (MSPs). MAPs and MSPs allow for inter-arrival and service times to be dependent, while providing the analytical tractability of simple Markov processes. To this end, we prove fluid and diffusion limits for MAP_t/MSP_t/∞ queues by constructing a new Poisson process representation for the queueing dynamics and leveraging strong approximations for Poisson processes. As a result, the fluid and diffusion limit theorems illuminate how the dependence structure of the arrival or service processes can affect the sample path behavior of the queueing process. Finally, our Poisson representation for MAPs and MSPs is useful for simulation purposes and may be of independent interest.