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This article characterizes a family of preference relations over uncertain prospects that (a) are dynamically consistent in the Machina sense and, moreover, for which the updated preferences are also members of this family and (b) can simultaneously accommodate Ellsberg- and Allais-type paradoxes.Replacing the "mixture independence" axiom by "mixture symmetry" proposed by Chew, Epstein, and Segal (1991) for decision making under objective risk, and requiring that for some partition of the state space the agent perceives ambiguity and so prefers a randomization over outcomes across that partition (proper uncertainty aversion), preferences can be represented by a (proper) quadratic functional. This representation may be further refined to allow a separation between the quantification of beliefs and risk preferences that is closed under dynamically consistent updating. 相似文献
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This paper deals with multi-stage lotsizing models for imperfect production processes. The effect of imperfect quality on lotsizing decisions and effect ofinspection errorsare taken into consideration in the proposed models. Numerical examples are presented for illustration purposes. The developed models are very helpful for justifying quality assurance and quality improvement efforts. 相似文献
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TÜRKAY S. NEFES 《Journal of historical sociology》2012,25(3):413-439
This paper investigates the history of social constructions, principally conspiracy theories, about a crypto‐Jewish group, the Dönmes, in Turkey. It considers the socio‐political reasons for the conspiracy theories and their significance by analysing their contents in different periods. The findings suggest that the fluid identity of Dönmes makes them stranger figures, in a sociological sense, creates public mistrust and encourages conspiratorial explanations. Moreover, the study shows that the conspiracy theories surrounding Dönmes are also fed by the ontological insecurities of Turkish politics, and that conspiracy theories tend to have appeal for alienated groups during major social transformations. 相似文献
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We examine the antecedents of professionalization in boards of firms affiliated to family business groups, increasingly recognized in the literature as the dominant form of big business organization in many late‐industrializing countries. Dimensions of board professionalization that we include in our study are board size, ratio of salaried executives and outsider presence. We compare predictions on board composition derived from contingency, institutional and power perspectives. Turkish family business groups, considered as an archetypal example of this form of organization, provide the empirical setting for the study, with data on 299 firms affiliated to ten different family business groups. Our results provide greater support for institutional and power perspectives, showing that, relative to internal and external complexity facing affiliate firms, institutional pressures and the presence of joint venture partners better predict board professionalization. 相似文献
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The hazard function plays an important role in reliability or survival studies since it describes the instantaneous risk of failure of items at a time point, given that they have not failed before. In some real life applications, abrupt changes in the hazard function are observed due to overhauls, major operations or specific maintenance activities. In such situations it is of interest to detect the location where such a change occurs and estimate the size of the change. In this paper we consider the problem of estimating a single change point in a piecewise constant hazard function when the observed variables are subject to random censoring. We suggest an estimation procedure that is based on certain structural properties and on least squares ideas. A simulation study is carried out to compare the performance of this estimator with two estimators available in the literature: an estimator based on a functional of the Nelson-Aalen estimator and a maximum likelihood estimator. The proposed least squares estimator tums out to be less biased than the other two estimators, but has a larger variance. We illustrate the estimation method on some real data sets. 相似文献
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In the late 1980s and early 1990s, it was noted that retailers in Britain had started providing increased variety and fashionability to their customers, had added mid‐season purchasing to their previous two‐season calendars, and that a high fashion and low price ‘throwaway market’ had appeared on the retail scene. Since then mid‐season purchasing has evolved into purchasing throughout the year; and the ‘throwaway market’ (now called fast fashion) has become almost the norm. Here we revisit one of those British retailers (Marks & Spencer) together with its Turkish suppliers and observe a trend towards the diffusion of design capabilities to suppliers that is more widespread than is suggested in the literature. We also consider the question of how most appropriately to conceptualize the nature of these retailer‐ supplier relations in today's circumstances. We especially look into the manner in which these relations are reflected in price negotiations, the eventual distribution of the value‐added, and the nature of everyday interactions such as accreditation and reclamation practices. We conclude that even though Turkish suppliers seem to be successfully upgrading into design–a high value‐added activity–the question of whether or not this development has entailed a renegotiation of power between retailer and supplier remains a complicated one. 相似文献
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Ülkü Gürler 《统计学通讯:理论与方法》2013,42(24):4409-4416
In most reliability studies involving censoring, one assumes that censoring probabilities are unknown. We derive a nonparametric estimator for the survival function when information regarding censoring frequency is available. The estimator is constructed by adjusting the Nelson–Aalen estimator to incorporate censoring information. Our results indicate significant improvements can be achieved if available information regarding censoring is used. We compare this model to the Koziol–Green model, which is also based on a form of proportional hazards for the lifetime and censoring distributions. Two examples of survival data help to illustrate the differences in the estimation techniques. 相似文献
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The mixture distribution models are more useful than pure distributions in modeling of heterogeneous data sets. The aim of this paper is to propose mixture of Weibull–Poisson (WP) distributions to model heterogeneous data sets for the first time. So, a powerful alternative mixture distribution is created for modeling of the heterogeneous data sets. In the study, many features of the proposed mixture of WP distributions are examined. Also, the expectation maximization (EM) algorithm is used to determine the maximum-likelihood estimates of the parameters, and the simulation study is conducted for evaluating the performance of the proposed EM scheme. Applications for two real heterogeneous data sets are given to show the flexibility and potentiality of the new mixture distribution. 相似文献