Summary For technological applications it can be useful to identify some simple physical mechanisms, which, on the basis of the available
knowledge of the production process, may suggest the most appropriate approach to statistical control of the random quantities
of interest. For this purpose the notion of rupture point is introduced firstly. A rupture point is characterized bym randomly arising out of control states, assumed to be mutually exclusive and stochastically independent. Shewhart's control
charts seem to represent the natural statistical tool for controlling a rupture point; however it is shown that they are fully
justified only when the hazard rates attached to the causes of failure are constant. Otherwise, typically in the presence
of time increasing hazard rates, Shewhart's control charts should be completed by a preventive intervention rule (preventive
maintenance). In the second place, the notion of dynamic instability point is introduced, which is specifically characterized
by assuming that the random quantity of interest is ruled by a stochastic differential equation with constant coefficients.
By discretization, developed according to a possibly new approach, it is shown that the former model reduces to an equation
error model, which is among the simplest used in adaptive control, and thus particularly easy to deal with in regard to parameter
estimation and the definition of the optimum control rule. 相似文献
We study, from the standpoint of coherence, comparative probabilities on an arbitrary familyE of conditional events. Given a binary relation ·, coherence conditions on · are related to de Finetti's coherent betting system: we consider their connections to the usual properties of comparative probability and to the possibility of numerical representations of ·. In this context, the numerical reference frame is that of de Finetti's coherent subjective conditional probability, which is not introduced (as in Kolmogoroff's approach) through a ratio between probability measures.Another relevant feature of our approach is that the family & need not have any particular algebraic structure, so that the ordering can be initially given for a few conditional events of interest and then possibly extended by a step-by-step procedure, preserving coherence. 相似文献
Empirical studies have documented a decline in indicators of social participation in the last five decades. The responsibility of social disengagement has often been attributed to pervasive busyness and the increasing pressure on time. In this paper we argue that computer-mediated interaction, and particularly online networking, can help mitigate this downward trend. We develop a logical framework for assessing the role of the Internet in the evolution of social participation. We analyze an economy where agents can develop their social interactions through two main modes of participation, one encompassing both online networking and face to face interactions, and the other solely based on physical encounters. We study the interdependence between the increase in the pressure on time and the variation in the relative performance of the two strategies of participation. 相似文献
Cet article traite, en premier lieu, du problème de la définition d'une méthode d'enquête, appropriée à l'analyse et à la compréhension de la réalité sociale. Il le fait en partant de la critique du modèle cognitiviste-comportementaliste que l'on peut relier aux noms de Boudon et Weber. Les intérêts, mais aussi et surtout les carences de ce modèle sont mis en évidence. Etant donné qu'il occupe, parmi les schémas méthodologiques apprêtés à la recherche sociologique, une place d'honneur pour sa rigueur et sa fécondité analytique, ses carences soulignent avec une clarté particulière non seulement les difficultés que la pensée sociale rencontre dans le domaine de la méthode, mais aussi les conséquences négatives de celles-ci sur la scientificité de l’élaboration théorique, entendue comme la capacité à interpréter et à expliquer la réalité de référence.
La critique de l’élaboration de R. Boudon sur la méthode aide aussi à mettre en évidence, par contraste, les motifs, les caractéristiques et les potentialités de notre proposition méthodologique, qui est présentée tout de suite après. Sur la base de cette proposition, que nous appelons objectivisme social, nous avons formulé non seulement des objections au relativisme culturel de Weber et à l'anti-relativisme culturel et cognitif de R. Boudon, mais aussi à la notion de rationalité et à la théorie sur l’évolution sociale de ce dernier auteur.
Parallèlement, sont proposées une notion de rationalité différente et une explication alternative des processus sociaux, laquelle embrasse des aspects concernant tant l’évolution que l'organisation des sociétés humaines et qui peut être facilement étendue aussi à l'interprétation des processus historiques. 相似文献
Under the pressure of population aging the Italian pension system has undergone reforms to increase labor force participation and retirement age, and, thus, the length of working life. However, how the duration of working life has developed in recent years is not well understood. This paper is the first to analyze trends in working life expectancy in Italy. We use data from a nationally representative longitudinal sample of 880,000 individuals from 2003 to 2013 and estimate working life expectancy by gender, occupational category, and region of residence using a Markov chain approach. We document large and increasing heterogeneity in the length of working life. From 2003–2004 to 2012–2013, working life expectancy for men declined from 35.2 to 27.2 years and for women from 34.7 to 23.7 years, increasing the gender gap to 3.5 years. Both young and old were hit, as roughly half of the decline was attributable to ages below 40, half above 40. Working life expectancy declined for all occupational groups, but those in manual occupations lost most, 8.5 years (men) and 10.5 years (women). The North–South economic gradient widened such that men living in the North were expected to work 8 years longer than women living in the South. The fraction of working life of total life expectancy at age 15 declined to record lows at 40% for men and 34% for women in 2012–2013. Policies aiming at increasing total population working life expectancy need to take into consideration the socio-demographic disparities highlighted by our results.
ABSTRACTResidential care is one of the most restrictive out-of-home care settings; however, this is a temporary placement and youth eventually reintegrate into the home and community setting. Reintegration presents many challenges, and aftercare becomes critical for maintaining youth gains and promoting family stability. Aftercare programs and supports should align to individual family needs that entail understanding individual and familial characteristics. Previous studies have explored characteristics related to family functioning, mental health, behavior, and perceptions of need during reintegration; yet little is known regarding how affective characteristics (i.e., self-efficacy, empowerment) factor into reintegration, or the implications this may have for providers. The purpose of this study was to address this gap by exploring empowerment and self-efficacy in caregivers (N = 120) who had a child return home within 1 month of departing residential care. Overall, caregivers reported high levels of empowerment and self-efficacy during the initial transition period. Significant differences for empowerment and self-efficacy were present in characteristics such as race, income, number of children in the home, and free/reduced lunch status. 相似文献
Aim of this article is to address the issue of citizen participation and democratic engagement within a specific area—slum
upgrading—presenting and theoretically discussing the approach of an international network called Shack/Slum Dwellers International
(SDI), which represents member federations of urban poor and homeless groups from about 30 countries in Asia, Africa, and
Latin America. The article addresses the model of intervention embraced by the network, the activities carried out, its philosophy,
etc., mainly focusing on the way it envisions and pursues the engagement of local governments in upgrading slum dwellers living
conditions. The basic idea within SDI is that the lack of participation by the urban poor has historically been one of the
major obstacles to achieve real development: either the government or the donors’ agencies, in fact, usually treat the poor
as beneficiaries of someone else’s actions, thus undervaluing their knowledge and skills. Radically opposing this view, SDI
interprets its role not as an intermediary agency of slum dwellers in the engagement/negotiation with local governments but
rather as an “enabling tool” of direct negotiation between the urban poor and the public institutions. SDI’s most relevant
feature, in fact, is surely the genuine leading role assigned to the slum dwellers grassroots organizations. 相似文献
The relationship between physicians' nonverbal sensitivity and the satisfaction of their patients was tested in two field studies. In the first study, 40 physicians were given a film test of nonverbal sensitivity (the PONS test) and were evaluated by their patients. The second study was a replication using 31 additional physicians. Most noteworthy for research in therapeutic interaction, the present studies contained three methodological advances: (1) the use of actual patients' ratings of satisfaction with treatment, (2) the extension of research from psychological to medical settings, and (3) the use of a standardized test of nonverbal decoding skill. Physicians' skill at reading the emotion conveyed through the nonverbal channel of body movement was found to be significantly correlated with their interpersonal success with patients in the clinical setting.The authors would like to thank Donald Dickson, M.D., Mary Ann Spadaro, M.D., Louise M. Prince, John L. Helmuth, Jr., Helene M. Murphy, and the physicians and patients who participated in the research. Study I was supported by a Peter B. Livingston Fellowship from the Massachusetts Mental Health Center and Study II by a W. K. Kellogg Fellowship from the Hospital Research and Educational Trust, both to the senior author. 相似文献