广义集压缩映射原理及其对积分方程组的应用

本文对Banach空间中映射组证明了一个不动点定理.利用这个定理,我们给出了Banach空间中非线性Fredholm和Volterra积分方程组解的存在性定理,也获得了非线性Volterra积分方程组极值解的存在定理和比较定理.这些定理推广了文[1]中的相应结果.     

Modelling spatially correlated data via mixtures: a Bayesian approach

Summary. The paper develops mixture models for spatially indexed data. We confine attention to the case of finite, typically irregular, patterns of points or regions with prescribed spatial relationships, and to problems where it is only the weights in the mixture that vary from one location to another. Our specific focus is on Poisson-distributed data, and applications in disease mapping. We work in a Bayesian framework, with the Poisson parameters drawn from gamma priors, and an unknown number of components. We propose two alternative models for spatially dependent weights, based on transformations of autoregressive Gaussian processes: in one (the logistic normal model), the mixture component labels are exchangeable; in the other (the grouped continuous model), they are ordered. Reversible jump Markov chain Monte Carlo algorithms for posterior inference are developed. Finally, the performances of both of these formulations are examined on synthetic data and real data on mortality from a rare disease.     

Banach空间中线性流形的单值度量投影算子部分

刘晶和王玉文于2001年引入并研究了Banach空间中线性流形的单值度量投影算子部分，但他们是在空间X和Y均自反、严格凸的强几何假定下来进行讨论的，这极不利于应用．我们在X和Y均是一般Banach空间的弱假定下，讨论并研究了Banach空间中线性流形的单值度量投影算子部分，并给出了该算子部分的结构的刻划．这为将比Lee S.J.与Nashed M.Z.所引进并研究的Hilbert空间集值线性映射包含的最小二乘解推广到Banach空间奠定了理论基础，所得的本质地推广了刘晶与王玉文的结果。     

V形、椭圆形、圆形微屏蔽共面线的解析分析(英文)

提出了三种新型微波毫米波单片电路共面传输线:V 形、椭圆形、圆形微屏蔽共面波导,假设其传播模式为纯 TEM 模并且不考虑色散,利用保角变换获得其特性阻抗的精确表达式,数值计算结果显示了不同的微屏蔽对其特性阻抗的影响。     

Best Spatial Two-Stage Least Squares Estimators for a Spatial Autoregressive Model with Autoregressive Disturbances

Estimation of a cross-sectional spatial model containing both a spatial lag of the dependent variable and spatially autoregressive disturbances are considered. [Kelejian and Prucha (1998)]described a generalized two-stage least squares procedure for estimating such a spatial model. Their estimator is, however, not asymptotically optimal. We propose best spatial 2SLS estimators that are asymptotically optimal instrumental variable (IV) estimators. An associated goodness-of-fit (or over identification) test is available. We suggest computationally simple and tractable numerical procedures for constructing the optimal instruments.     

The variability of rainfall acidity

Two years of rainfall acidity data for the eastern United States were analyzed. The data consist of rainfall-event pH measurements from a nine station monitoring network. A spatio-temporal stochastic model, including deterministic components for seasonal variation and rainfall washout, and stochastic components for spatial, temporal, and measurement variation, was fitted to the data. The fitted autocorrelation structure from this model was used, in the process known as Kriging, to obtain BLUE contour maps of seasonal and rainfall adjusted yearly average pH over the monitoring region.     

关于一集类圆柱投影的探讨

本文所要探讨的是一集类圆柱投影。它不同于伪圆柱投影,而属于标准线型投影族的一个新类型;其中包含着两个新型的等面积投影。     

Adaptive Gaussian Markov random fields with applications in human brain mapping

Summary.  Functional magnetic resonance imaging has become a standard technology in human brain mapping. Analyses of the massive spatiotemporal functional magnetic resonance imaging data sets often focus on parametric or non-parametric modelling of the temporal component, whereas spatial smoothing is based on Gaussian kernels or random fields. A weakness of Gaussian spatial smoothing is underestimation of activation peaks or blurring of high curvature transitions between activated and non-activated regions of the brain. To improve spatial adaptivity, we introduce a class of inhomogeneous Markov random fields with stochastic interaction weights in a space-varying coefficient model. For given weights, the random field is conditionally Gaussian, but marginally it is non-Gaussian. Fully Bayesian inference, including estimation of weights and variance parameters, can be carried out through efficient Markov chain Monte Carlo simulation. Although motivated by the analysis of functional magnetic resonance imaging data, the methodological development is general and can also be used for spatial smoothing and regression analysis of areal data on irregular lattices. An application to stylized artificial data and to real functional magnetic resonance imaging data from a visual stimulation experiment demonstrates the performance of our approach in comparison with Gaussian and robustified non-Gaussian Markov random-field models.     

一种新的内插算法的研究

有效的插值算法是现代医学三维成像中的一个焦点。针对ＣＴ断层图像的特点，文中提出了一种新的分区域位置映射插值算法，阐明了算法的基本思路及实施步骤，最后给出实验结果。     

博弈论科学文献的可视化分析

为明确博弈论的全球研究态势,文章以以博弈论研究为主的两本代表性期刊Games And Economic Behavior与International Journal Of Game Theory的2115篇论文为研究对象,绘制了该领域的科学知识图谱,借助CiteSpace II对博弈论的全球研究力量分布、作者分布、研究热点和知识基础进行了分析。结果显示：在机构研究力量的分布上,美国、以色列等国的8所高校有很强实力;在国家分布上,美国、以色列以及西班牙等国家有较强的研究实力,而德国、加拿大以及荷兰等国在博弈论研究国际合作中有重要作用。对作者的分析得到了一批在该研究上有影响的科学家,特别是一批获得诺贝尔奖的经济学家;对博弈论研究高频关键词和文献共被引网络的分析得到了博弈论研究的热点词汇及在博弈论发展过程中有重要作用的关键文献。