Output-Flexibilität in der Dienstleistungsproduktion

Zusammenfassung  Den Ausgangspunkt der überlegungen bildet die Interpretation von Dienstleistungen als Probleml?sungen, die eine M?glichkeit zur formalen Analyse der Output-Flexibilit?t er?ffnet. Im vorliegenden Beitrag werden in einer eigenschaftsorientierten Betrachtung zun?chst die Komponenten der Output-Flexibilit?t identifiziert, um dann darauf aufbauend ein Kalkül zur Gestaltung der Output-Flexibilit?t von Dienstleistungsunternehmungen abzuleiten.

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Summary  Output flexibility enables the service provider to cope with both uncertainties in demand and the external production factor. This paper aims at formulating a calculus for the design of output flexibility based on production theory. The interpretation of services as specific problem solutions serves as a basis for a feature-oriented modelling of service production.

Die Autoren danken zwei anonymen Gutachtern für wertvolle Verbesserungsvorschl?ge.     

Consumer Selection of Food-Safety Information Sources

The aim of this study is to examine the preferences of consumers for different information sources when they have a question about food safety. On the basis of a nationally representative survey conducted in the Netherlands, five distinct consumer groups are identified that not only differ on the reported use of information sources but also regarding several personality characteristics and sociodemographic variables. The empirical results show that two-thirds of the consumers are selective in their use of information sources and prefer either institutional or social sources. So, multiple information-acquisition patterns exist among the general public. The study illustrates how these findings can help to develop effective risk communication strategies.     

Dynamic Pricing to Minimize Maximum Regret

We consider a dynamic pricing problem that involves selling a given inventory of a single product over a short, two‐period selling season. There is insufficient time to replenish inventory during this season, hence sales are made entirely from inventory. The demand for the product is a stochastic, nonincreasing function of price. We assume interval uncertainty for demand, that is, knowledge of upper and lower bounds but not a probability distribution, with no correlation between the two periods. We minimize the maximum total regret over the two periods that results from the pricing decisions. We consider a dynamic model where the decision maker chooses the price for each period contingent on the remaining inventory at the beginning of the period, and a static model where the decision maker chooses the prices for both periods at the beginning of the first period. Both models can be solved by a polynomial time algorithm that solves systems of linear inequalities. Our computational study demonstrates that the prices generated by both our models are insensitive to errors in estimating the demand intervals. Our dynamic model outperforms our static model and two classical approaches that do not use demand probability distributions, when evaluated by maximum regret, average relative regret, variability, and risk measures. Further, our dynamic model generates a total expected revenue which closely approximates that of a maximum expected revenue approach which requires demand probability distributions.     

How People Perceive and Will Cope with Risks from the Diffusion of Ubiquitous Information and Communication Technologies

Information and communication technologies (ICTs) are increasingly pervasive and continue to reshape our environment. This trend carries different risks. Therefore, the early sensitization of people to these risks, as well as improving their capacity for protective coping behavior, is essential. Based on the protection motivation theory (PMT), we examined with structural equation modeling the relationships between different components of threat and coping appraisal to explain protective and nonprotective responses. Calculations were performed with data from a representative survey on perception and use of ICT among German residents (N= 5,030). Our findings largely supported the proposed model: an increased perceived threat was positively related to the intentions to react protectively and nonprotectively. Perceived coping efficacy increased the protective and decreased the nonprotective responses. Negative affect enhanced the perceived threat and the nonprotective response, but inhibited protective intentions. The implications of these findings on how to sensitize people to the risks of these new technologies are outlined.     

Compliance Versus Risk in Assessing Occupational Exposures

Assessments of occupational exposures to chemicals are generally based upon the practice of compliance testing in which the probability of compliance is related to the exceedance [γ, the likelihood that any measurement would exceed an occupational exposure limit (OEL)] and the number of measurements obtained. On the other hand, workers’ chronic health risks generally depend upon cumulative lifetime exposures which are not directly related to the probability of compliance. In this paper we define the probability of “overexposure” (θ) as the likelihood that individual risk (a function of cumulative exposure) exceeds the risk inherent in the OEL (a function of the OEL and duration of exposure). We regard θ as a relevant measure of individual risk for chemicals, such as carcinogens, which produce chronic effects after long-term exposures but not necessarily for acutely-toxic substances which can produce effects relatively quickly. We apply a random-effects model to data from 179 groups of workers, exposed to a variety of chemical agents, and obtain parameter estimates for the group mean exposure and the within- and between-worker components of variance. These estimates are then combined with OELs to generate estimates of γ and θ. We show that compliance testing can significantly underestimate the health risk when sample sizes are small. That is, there can be large probabilities of compliance with typical sample sizes, despite the fact that large proportions of the working population have individual risks greater than the risk inherent in the OEL. We demonstrate further that, because the relationship between θ and γ depends upon the within- and between-worker components of variance, it cannot be assumed a priori that exceedance is a conservative surrogate for overexposure. Thus, we conclude that assessment practices which focus upon either compliance or exceedance are problematic and recommend that employers evaluate exposures relative to the probabilities of overexposure.     

Efficient estimation for incomplete multivariate data

We review the Fisher scoring and EM algorithms for incomplete multivariate data from an estimating function point of view, and examine the corresponding quasi-score functions under second-moment assumptions. A bias-corrected REML-type estimator for the covariance matrix is derived, and the Fisher, Godambe and empirical sandwich information matrices are compared. We make a numerical investigation of the two algorithms, and compare with a hybrid algorithm, where Fisher scoring is used for the mean vector and the EM algorithm for the covariance matrix.     

Nonparametric regression estimation in a null recurrent time series

We derive an asymptotic theory of nonparametric estimation for a time series regression model Z_t=f(X_t)+W_t, where {X_t} and {Z_t} are observed nonstationary processes, and {W_t} is an unobserved stationary process. The class of nonstationary processes allowed for {X_t} is a subclass of the class of null recurrent Markov chains. This subclass contains the random walk, unit root processes and nonlinear processes. The process {W_t} is assumed to be linear and stationary.     

具体人性——人权与宽容的新维度

简要列出宽容概念的种类,并概述人权与实际(或具体)人性之间的关联以及实质性的相互关系,基于针对人权的进一步区别、历史修正以及人权阐释的发展的评论,勾勒出人权从保护性人权向供人分享和有积极创造性的人权的发展历程,并提出与标准的法定人权相比,供人分享和有积极创造性的人权是对伦理上的真正尊严的主张,是一种道德人的准权利。因此,用“具体人性”和对具体人性的实际描述真正代替仅仅沉湎于人性和人道的相当抽象的观念,这在所有的人权教育中都是最重要的。     

从胡文化“汉化”看生态环境的迁移对文化转型的影响

不同文化特质的形成 ,除受政治经济影响外 ,还受特定生态环境的制约。胡汉两大文化体系的差异 ,在很大程度上就是不同生态环境作用的结果。与此相应 ,文化的发展一旦脱离了与自身相适应的环境 ,就势必要出现势能上的劣势 ,并逐渐与异地文化相溶     

论1807年的现象学的逻辑

在研究黑格尔《精神现象学》的内容时,应该同时研究其体系学的形式。1807年的现象学是建立在诸逻辑基本环节的某种序列的基础上的,而这种序列与黑格尔当时的逻辑学构想是相一致的,并且在现象学内具有一种统一的功能。要弄清这些基本规定之进程,有着诸多困难。在现象学的布局中的修改并没有走到损害现象学之逻辑根基的地步。本文第一章表明,从一开始,黑格尔就提出了这一要求:在非实在的意识的方式与逻辑的环节之间要有一种严格的对应。第二章讨论这些逻辑的环节作为什么进入意识的经验当中,以及它们如何组织意识的经验。第三章具体说明这些逻辑的基本环节的序列及其同意识的诸阶段的对应。文章最后还把一种有关现象学的方法和有关耶拿逻辑学的发展的见解,提出来进行了讨论。