A probablistic analysis for an optimal screening problem

Summary We consider a lotL formed byN apparently similar unitsW ₁,…,W _N, where each of theW _i may come from one of two different populationsP ₁ andP ₂;T ₁,…,T _N denote the corresponding lifetimes. The units fromP _i undergo a failure of kindi and their survival function isS _i (t). We assume that the failure rate function are known and that the units fromP ₁ are ?substandard?: λ ₁ (t)≥λ ₂ (t), ∀t≥0. We want to putW ₁,…,W _N under a pre-operational test (burn-in test) in order to eliminate at least a great part of the substandard units and we face the problem of obtaining a rule for stopping the test under the assumption that, with the failure of a unit, it is possible to recognize the population from which the unit comes. Such a problem will be formalized as an optimal stopping problem for a suitably defined Markov process. Our study shall evidentiate some fundamental aspects of the problem and the role of the prior distribution of the (random) numberM ₀ of those units inL coming fromP ₁ (substandard). The latter distribution has a great influence on the form of the solution. This research was supported by the C.N.R. Project ?Statistica Bayesiana e Simulazione in Affidalità e Modellistica Biologica?.     

Physician executives' persuasive styles of communication in upward influence situations

This article examines the communicator style choices of physician executives when attempting to persuade a superior whose own style of communication is attractive and unattractive. In the November-December 1990 issue of Physician Executive, the author reported on persuasive strategies physician executives use to influence such targets of influence. Whereas the earlier study focused on what physician executives communicate to be persuasive, the present investigation treated the way physician executives communicate to persuade attractive and unattractive superiors. The results suggest that the way physician executives communicate in upward influence situations is affected by the way their superiors communicate with them.     

Physician perceptions of medical malpractice and defensive medicine

Using judgments obtained in interviews with 33 Massachusetts physicians, the annual statewide volume of expenditures incurred for defensive medical reasons in 1982 was estimated to be $1.0 billion, 12% of all medical care expenditures. Estimates for the nation were $37 billion, 14% of expenditures. Nationally, 180,000 cesarean deliveries were thought to be performed for defensive motives. In their own institutions, respondents judged 43% of all skull x-rays following injury to be medically justified, 30% to be defensive medicine, 16% to be placebos, and 11% to be physician misjudgments. In considering the economic and noneconomic costs of medical malpractice procedures, the dollar costs of insurance were considered most serious, followed closely by defensive medicine, unfairness, and poorer relations with patients. Thirty-two percent of the responsibility for the negative aspects of malpractice processes was assigned to lawyers, 21% to physicians, 18% to legislatures and courts, 16% to patients, and 13% to insurance companies.     

Eye-contact as a chance product of individual looking: Implications for the intimacy model of argyle and dean

From time to time during social encounters, people look at one another in the region of the eyes, and sometimes their eyes meet to make eye-contact. According to Argyle and Dean (1965), eye-contact in dyadic encounters signals the intimacy of the interaction and is controlled largely by the competing approach and avoidance forces that motivate the pair. In the present paper, new analyses are reported of three published experiments that were designed originally to test aspects of the intimacy model and it is shown that the duration of eye-contact is no more than a chance product of how long the two subjects look individually. Looking and not eye-contact, it is argued, should be the basis for models of visual interaction, and the intimacy model is ill-founded conceptually; the role of emotion in gaze has been overstressed at the expense of the concept of information; and the most important aspect of vision is in any case not looking and eye-contact but visual access to the whole person. The more cueless the encounter—that is, the fewer the social cues from vision and all the other senses combined—the greater the psychological distance; and the greater the psychological distance, the more task-oriented and depersonalized the content of what people say and, in turn, the less spontaneous their style of speech and the less likely a debate to end in compromise.Research for this article was sponsored by the Social Science Research Council of Great Britain.     

An analysis of cyclically dense data using EBLOC

Everett (1982a) has proposed a graph theoretic technique for analysing social networks. It is not usually possible to apply this method to data which contain a large number of interlocking cycles. We demonstrate a technique which overcomes this problem by referring to the data analysed by MacRae (1960).     

Mental health services for Chinese in a community health center

Serious mental health problems exist within the Chinese population of the United States. This article describes one center's attempt to meet the psychiatric needs of both nonpsychotic and psychotic Chinese patients through bilingual, culturally relevant treatments.