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Kernel smoothing of spatial point data can often be improved using an adaptive, spatially varying bandwidth instead of a fixed bandwidth. However, computation with a varying bandwidth is much more demanding, especially when edge correction and bandwidth selection are involved. This paper proposes several new computational methods for adaptive kernel estimation from spatial point pattern data. A key idea is that a variable-bandwidth kernel estimator for d-dimensional spatial data can be represented as a slice of a fixed-bandwidth kernel estimator in \((d+1)\)-dimensional scale space, enabling fast computation using Fourier transforms. Edge correction factors have a similar representation. Different values of global bandwidth correspond to different slices of the scale space, so that bandwidth selection is greatly accelerated. Potential applications include estimation of multivariate probability density and spatial or spatiotemporal point process intensity, relative risk, and regression functions. The new methods perform well in simulations and in two real applications concerning the spatial epidemiology of primary biliary cirrhosis and the alarm calls of capuchin monkeys.  相似文献   
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In equilibrium play of a two-round tournament, we find that underdogs exert more effort in the opening round whereas favorites save more effort for the final. Ability differences are therefore compressed in the opening round so upsets are more likely and amplified in the final so blowouts are more likely. Measures that reduce the need to strategically allocate effort make for a more exciting final but a less exciting opening round. Consistent with the model, introduction of a rest day between matches in the NCAA men's basketball tournament increased the favorite's victory margin in the semifinals by about five points.(JEL L83 , D72 )  相似文献   
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Survey-based studies on the prevalence and causes of deviant behaviour very much depend on the honesty of respondents. However, the validity of self-reports is rarely investigated. We report on a external validation of self-reported delinquency of male juveniles based on two survey samples — face-to-face interviews in households (N=309), and paper and pencil interviews in school (N=337) — which have been done in 1999 and 2000 in Freiburg and are used for record checks of self-reported police contacts both on the individual and aggregate level. Individual-level record checks reveal that a majority of respondents has honestly reported contacts with the police, while there are a considerable number of both ‘false negative’ and ‘false positive’ answers which come predominately from respondents with low educational and social status and of migration background. As these groups show high non-response rates as well, the correlation between delinquency and socio-economic status is likely to be underestimated. The school survey, on the other hand, yields higher and more realistic prevalence rates. However, comparisons between the two survey modes hint at differential effects of social desirability which question the validity of self-reports by respondents with high educational status. Survey results on self-reported delinquency should generally be interpreted with great caution, and more research on the mode effects of class room interviews are deemed necessary.  相似文献   
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In this paper, we present a new method for determining optimal designs for enzyme inhibition kinetic models, which are used to model the influence of the concentration of a substrate and an inhibition on the velocity of a reaction. The approach uses a nonlinear transformation of the vector of predictors such that the model in the new coordinates is given by an incomplete response surface model. Although there exist no explicit solutions of the optimal design problem for incomplete response surface models so far, the corresponding design problem in the new coordinates is substantially more transparent, such that explicit or numerical solutions can be determined more easily. The designs for the original problem can finally be found by an inverse transformation of the optimal designs determined for the response surface model. We illustrate the method determining explicit solutions for the D-optimal design and for the optimal design problem for estimating the individual coefficients in a non-competitive enzyme inhibition kinetic model.  相似文献   
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Due to a rising interest in empirical ‘respect’ research but at the same time a somewhat fuzzy use of the term and its semantically close neighbors, we introduce a conceptual framework. The framework draws on existing philosophical traditions and empirical psychological works alike. It is pointed out that respect, acceptance, and tolerance are all attitudes of a subject towards an object which are not aligned on one dimension, but are concerned with quite different issues. Moreover, we propose that research needs to differentiate between two very different kinds of respect. Whereas appraisal respect, acceptance, and tolerance are attitudinal reflections of a subject’s decisions on certain issues (i.e., on influence, membership, and presence), recognition respect is proposed to be an overarching processing mode, i.e., a general attitude on how to confront others.  相似文献   
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This paper considers learning rules for environments in which little prior and feedback information is available to the decision maker. Two properties of such learning rules are studied: absolute expediency and monotonicity. Both require that some aspect of the decision maker's performance improves from the current period to the next. The paper provides some necessary, and some sufficient conditions for these properties. It turns out that there is a large variety of learning rules that have the properties. However, all learning rules that have these properties are related to the replicator dynamics of evolutionary game theory. For the case in which there are only two actions, it is shown that one of the absolutely expedient learning rules dominates all others.  相似文献   
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Recent literature on private‐sector development emphasises the need to establish a ‘level playing field’ and tends to disregard selective supportive interventions. The most commonly highlighted elements are administrative simplification and effective property rights policies, with business services largely left to private providers ‐ what we call the ‘new minimalist approach’ (NMA). However, the NMA is based on certain unrealistic assumptions and is barely backed by empirical evidence. A range of complementary public policies is needed to create competitive sectors and overcome internal constraints, especially in small‐scale economies.  相似文献   
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