Likelihood Inference for Unions of Interacting Discs

Abstract. This is probably the first paper which discusses likelihood inference for a random set using a germ‐grain model, where the individual grains are unobservable, edge effects occur and other complications appear. We consider the case where the grains form a disc process modelled by a marked point process, where the germs are the centres and the marks are the associated radii of the discs. We propose to use a recent parametric class of interacting disc process models, where the minimal sufficient statistic depends on various geometric properties of the random set, and the density is specified with respect to a given marked Poisson model (i.e. a Boolean model). We show how edge effects and other complications can be handled by considering a certain conditional likelihood. Our methodology is illustrated by analysing Peter Diggle's heather data set, where we discuss the results of simulation‐based maximum likelihood inference and the effect of specifying different reference Poisson models.     

Adaptive weights smoothing with applications to image restoration

We propose a new method of nonparametric estimation which is based on locally constant smoothing with an adaptive choice of weights for every pair of data points. Some theoretical properties of the procedure are investigated. Then we demonstrate the performance of the method on some simulated univariate and bivariate examples and compare it with other nonparametric methods. Finally we discuss applications of this procedure to magnetic resonance and satellite imaging.     

Qdf misclassification probabilities for known population parameters

Approximated QDF misclassification probabilities have been derived for bivariate normal populations with known parameter values. Tne effect of unequal covariances and population distance on the misclassification probabilities are examined     

Policymakers' Use of Social Science Research: Looking Within and Across Policy Actors

Evidence‐informed policy creates the conditions for families to perform the functions they provide for their members and society. To increase research utilization in policymaking, we must better understand policymakers and the professional and institutional cultures in which they operate. This exploratory cluster analysis examined within‐group differences in valuing, seeking, and use of social science research among 68 legislative staffers and 56 high‐ranking officials from 8 family‐serving executive agencies in Wisconsin. The findings are compared with a parallel study of 109 legislators from New York and Wisconsin. Among all 3 policy actors, a substantial proportion highly value research, actively seek it, and frequently use it in policy decisions; these Enthusiastic High Users of research are more attuned to political considerations compared to other clusters. Enthusiastic High Users in the legislative institution place a higher priority on innovative and action‐oriented research, whereas those in the agency institution prioritize the quality of research.     

基于可拓理论的粮食物流中心选址研究

综合运用可拓决策方法、聚类分析、重心法，建立了基于可拓理论的粮食物流中心选址模型。将选址过程中的矛盾问题转换为相容问题进行研究，使选址结果更为合理。以山东省为例论证了模型求解方法的可行性。该模型还可应用到其它省乃至全国来进行粮食物流中心的选址决策，在实际应用中具备可操作性。     

基于组合漂移模型的订单流变化条件下汇率波动研究

通常,宏观名义汇率模型的预测效果很不理想,其R2统计量最高10%左右.针对这一现象,本文对汇率决定基础模型中的一个考虑微观因素的新模型做了实证分析,结果表明,组合漂移模型成功地解释了汇率变动,R2统计量超过了60%.在样本外预测中,本模型预测效果也明显优于随机游走模型.同样,本文估计即期汇率与订单流的敏感程度是相似的.这个结果将引导作者在研究过程中同时引入微观和宏观方法,而这种方式将可以更广泛地应用于资产定价方面的研究.     

SAR图像边缘检测方法综述

边缘检测是SAR图像解译的基本问题之一。固有的乘性噪声特性使得经典的梯度边缘检测方法并不适用于SAR图像,因此研究针对SAR图像的边缘检测方法具有重要的意义。本文对SAR图像边缘检测问题进行了系统的研究,简单描述了SAR图像边缘检测问题,讨论了现有的SAR图像边缘检测方法,总结了SAR图像边缘检测中存在的两个问题——边缘细化和边缘定位,对检测结果的性能评估方法也进行了概括。最后在总结现有研究成果的基础上展望了SAR图像边缘检测的发展方向。     

基于加权模糊c均值聚类的快速图像自动分割算法

图像分割是指将一幅图像分解为若干互不交迭的区域的集合，是图像处理和计算机视觉的基本问题之一。为了提高图像分割的效率，提出了一种基于2维直方图加权的塔形模糊c均值（FCM）聚类图像快速分割算法。该方法先通过构造合理的2维直方图对噪声进行抑制；然后通过塔形分解来缩减聚类样本集；最后利用加权FCM聚类算法进行分类。仿真结果表明，该方法的效率明显优于标准的FCM算法。此外，为确定分割的最优类别数c，还引入了一种基于该快速算法的聚类有效性评价函数——修正划分模糊度，实现了最佳图像分割类别数c的自动确定。基于人造图像和实际图像的测试实验结果表明该方法是有效的。     

城市化进程中的失地农民问题研究

随着中国经济的高速发展和城市化水平的不断提高,农地被大量征用并因此产生了为数众多的失地农民。农地征用中的不公正性,使失地农民的利益极大受损。同时,失地农民在向市民角色转变的过程中,又遭遇到种种因素的制约,无奈地沦为城市的“边缘人”。对农民失地的深层次原因及失地农民向市民角色转换的制约因素进行深入探讨,将有助于妥善、合理地解决失地农民的若干问题。     

金属簇合物的发展概况与研究趋势

本文对金属簇合物的研究进展作了概述，着重介绍了几种近几年合成的具有新结构形式和新成键方式的铁和钴等羰基簇合物，探讨了金属簇合物的研究趋势。