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31.
We examine the relationship between income inequality, poverty, and different types of crime. Our results are consistent with recent research in showing that inequality is unrelated to homicide rates when poverty is controlled. In our multi‐level analyses of the International Crime Victimization Survey we find that inequality is unrelated to assault, robbery, burglary, and theft when poverty is controlled. We argue that there are also theoretical reasons to doubt that the level of income inequality of a country affects the likelihood of criminal behaviour.  相似文献   
32.
This research extends prior work that examines self‐esteem as an outcome of protective behaviors against crime victimization by focusing instead on the moderating influence of self‐esteem on the relationship between the fear of crime and the decision to protect oneself from victimization. The fear of crime is conceptualized as two separate components (fear of victimization and perceived risk) in accordance with prior work. Self‐esteem is conceptualized as three separate components (worth, efficacy, and authenticity), and measured with a recently designed instrument for capturing each aspect of self‐esteem separately. Data are collected through surveys of a population at high risk for victimization (undergraduate college students). Logistic regression analyses demonstrate that self‐esteem does play a role for deciding whether to engage in protective behaviors, and that the specific components of self‐esteem moderate defensive behavioral outcomes differently. Specifically, the self‐worth, self‐efficacy, and authenticity components of self‐esteem influence the decision to carry protection, but not the decision to take a self‐defense class. Implications for both the fear of crime and self‐esteem literatures are addressed.  相似文献   
33.
Lead is a recognized neurotoxicant, but estimating effects at the lowest measurable levels is difficult. An international pooled analysis of data from seven cohort studies reported an inverse and supra‐linear relationship between blood lead concentrations and IQ scores in children. The lack of a clear threshold presents a challenge to the identification of an acceptable level of exposure. The benchmark dose (BMD) is defined as the dose that leads to a specific known loss. As an alternative to elusive thresholds, the BMD is being used increasingly by regulatory authorities. Using the pooled data, this article presents BMD results and applies different statistical techniques in the analysis of multistudy data. The calculations showed only a limited variation between studies in the steepness of the dose‐response functions. BMD results were quite robust to modeling assumptions with the best fitting models yielding lower confidence limits (BMDLs) of about 0.1–1.0 μ g/dL for the dose leading to a loss of one IQ point. We conclude that current allowable blood lead concentrations need to be lowered and further prevention efforts are needed to protect children from lead toxicity.  相似文献   
34.
In a missing-data setting, we want to estimate the mean of a scalar outcome, based on a sample in which an explanatory variable is observed for every subject while responses are missing by happenstance for some of them. We consider two kinds of estimates of the mean response when the explanatory variable is functional. One is based on the average of the predicted values and the second one is a functional adaptation of the Horvitz–Thompson estimator. We show that the infinite dimensionality of the problem does not affect the rates of convergence by stating that the estimates are root-n consistent, under missing at random (MAR) assumption. These asymptotic features are completed by simulated experiments illustrating the easiness of implementation and the good behaviour on finite sample sizes of the method. This is the first paper emphasizing that the insensitiveness of averaged estimates, well known in multivariate non-parametric statistics, remains true for an infinite-dimensional covariable. In this sense, this work opens the way for various other results of this kind in functional data analysis.  相似文献   
35.
This paper presents the findings of an exploratory study of the content of and differences between managerial frames of references with regard to the structure and dynamics of competitive environments. These frames of references are examined and compared at both the industry level and the country level; and the paper shows the influences of both industry and institutional structures and national culture on managerial thinking. It therefore contributes to the field of comparative management, as well as the growing interest in cognitive analysis in the field of management. The study is particularly significant since (a) its context is the rapidly changing industry environment of Europe, and (b) the managers are all involved in the development of strategies for their firms. Thirty three top managers (16 English and 17 French) were interviewed in four industries (brewing, car manufacturing, retail banking and book publishing) on their understanding of their industry and the strategy of their company. Content analysis of the transcribed interviews surfaces cognitive constructs which facilitate the identification of similarities and differences between managers, (a) within industries, (b) across industries, (c) within countries, (d) between countries and (e) between countries within the different industries. The analysis also provides means whereby the constructs can be represented in the form of cognitive maps.  相似文献   
36.
This article summarizes the results of research into the ways in which environmental forces are changing the management task of chief executive officers of large corporations. The article comments on the changing business environment; on the time spent by managers on environmental forces; changes in the basic strategies of managers concerned with major social and political environmental forces; the characteristics which chief executive officers believe their successors must have to be effective managers; major ways in which the impact of environment on the CEO is changing the infra-structure and decision-making process; and, finally, a brief look at the future.  相似文献   
37.

A method for evaluating the robustness of medium term multisite distributed schedule is presented. The method of robustness evaluation is based on steps and tools associated with the conceptual model of a MultiSite Reactive Production Activity Control (MSR-PAC). The MSR-PAC makes it possible to study the sensitivity of the scheduled plans in presence of perturbations. These must be evaluated before being dispatched to the shop-floors. At present, to the best of the authors' knowledge, there is no means to make this evaluation in the distributed systems such as extended enterprise. The monitoring of errors is based on the discrepancy between the two flow-shape functions that model respectively the dynamics of the scheduled manufacturing orders and the state of the perturbed production. The MSR-PAC is based on a multisite agent system and on the monitoring of the perturbed virtual jobshops. The method can also be used for controlling short term distributed production activities.  相似文献   
38.
Based on sero-prevalence data of rubella, mumps in the UK and varicella in Belgium, we show how the force of infection, the age-specific rate at which susceptible individuals contract infection, can be estimated using generalized linear mixed models (McCulloch & Searle, 2001). Modelling the dependency of the force of infection on age by penalized splines, which involve fixed and random effects, allows us to use generalized linear mixed models techniques to estimate both the cumulative probability of being infected before a given age and the force of infection. Moreover, these models permit an automatic selection of the smoothing parameter. The smoothness of the estimated force of infection can be influenced by the number of knots and the degree of the penalized spline used. To determine these, a different number of knots and different degrees are used and the results are compared to establish this sensitivity. Simulations with a different number of knots and polynomial spline bases of different degrees suggest - for estimating the force of infection from serological data - the use of a quadratic penalized spline based on about 10 knots.  相似文献   
39.
40.
The authors of this article argue that too many companies are not getting the benefits which should be produced by their long-range planning systems. Of the many possible explanations for this, the authors concentrate on the major pitfalls which should be avoided in order to ensure good results. The article is based upon the results of a survey of planning pitfalls among corporations in six industrialized countries.  相似文献   
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