An approximation to cluster size distribution of two Gaussian random fields conjunction with application to FMRI data

In brain mapping, the regions of the brain that are ‘activated’ by a task or external stimulus are detected by thresholding an image of test statistics. Often the experiment is repeated on several different subjects or for several different stimuli on the same subject, and the researcher is interested in the common points in the brain where ‘activation’ occurs in all test statistic images. The conjunction is thus defined as those points in the brain that show ‘activation’ in all images. We are interested in which parts of the conjunction are noise, and which show true activation in all test statistic images. We would expect truly activated regions to be larger than usual, so our test statistic is based on the volume of clusters (connected components) of the conjunction. Our main result is an approximate P-value for this in the case of the conjunction of two Gaussian test statistic images. The results are applied to a functional magnetic resonance experiment in pain perception.     

中国资产证券化发展选择评析

资产证券化作为强市场本位时期重要金融工具,其主要具有表外融资、未来收入抵押和现金收入担保等特征。近期中国推行资产证券化存在许多制度性障碍,而操作的切入点是实行住房抵押担保证券化。未来中国资产证券化的应用方向是化解和盘活银行不良资产。     

Break point detection for functional covariance

Many neuroscience experiments record sequential trajectories where each trajectory consists of oscillations and fluctuations around zero. Such trajectories can be viewed as zero-mean functional data. When there are structural breaks in higher-order moments, it is not always easy to spot these by mere visual inspection. Motivated by this challenging problem in brain signal analysis, we propose a detection and testing procedure to find the change point in functional covariance. The detection procedure is based on the cumulative sum statistics (CUSUM). The fully functional testing procedure relies on a null distribution which depends on infinitely many unknown parameters, though in practice only a finite number of these parameters can be included for the hypothesis test of the existence of change point. This paper provides some theoretical insights on the influence of the number of parameters. Meanwhile, the asymptotic properties of the estimated change point are developed. The effectiveness of the proposed method is numerically validated in simulation studies and an application to investigate changes in rat brain signals following an experimentally-induced stroke.     

中日经贸合作现状分析

中日经贸合作在整个中国对外经贸关系中占有重要地位 ,双方互为重要的合作伙伴。中日经贸合作的持续快速发展给两国带来了巨大的利益 ,越来越成为中日关系的重要支柱和推动力。 2 1世纪初的中日经贸关系是在不断“磨合”中向前发展的。尽管目前中日经贸合作中尚存在不少矛盾与磨擦 ,但两国之间已逐步形成一种多层次、多领域、优势互补、稳定发展的经贸合作框架。 2 1世纪初两国经贸合作将迎来一个新的发展时期。     

制度理论如何适宜于管理学研究?——制度创业者研究中的迷思及适宜性

通过对制度创业者研究中的3个关键内容——概念界定、研究发展阶段划分以及分析工具应用进行考察,论证制度创业者研究中存在的理论困境及原因,并提出采取与主流管理理论交会的方式解决适宜性问题。     

娱乐法的规范意蕴与体系构建

随着中国文化产业的蓬勃发展,文化娱乐领域法治水平的不断提升,文化娱乐法已然兴起并不断走向成熟。中国的文化娱乐法有其自身的鲜明特色,就其调整范围而言,包括文化事业和文化产业两大领域;就其法律原则来说,包括社会效益与经济效益相统一等四项基本原则;就其法律实践来说,主要包括行业监管、知识产权、人格权保护、投融资与保险等四个主要方面。未来的文化娱乐法将面临数字化、网络化、智能化时代带来的诸多挑战。     

米波雷达方位角超分辨外场实验研究

介绍了一个由均匀线接收阵和米波雷达组成的外场实验系统,用于进行米波雷达的方位角超分辨实验。用采集的实验数据对几种常用的超分辨算法进行了实验,结果表明,ＦＢＬＰ算法和ＥＳＰＡＩＴ算法可清晰分辨出角间隔为０．２～０．３波束宽度的两架飞机。     

DM——Q_2型数字式冲击电流计测定螺线管磁场

针对DM———Q2型数字式冲击电流计无法直接测定冲击常数K值这一问题,改进了计算公式的推导和测量方法,使测量方法更加便捷,结果更加精确。     

Variable selection in spatial regression via penalized least squares

We consider variable selection in linear regression of geostatistical data that arise often in environmental and ecological studies. A penalized least squares procedure is studied for simultaneous variable selection and parameter estimation. Various penalty functions are considered including smoothly clipped absolute deviation. Asymptotic properties of penalized least squares estimates, particularly the oracle properties, are established, under suitable regularity conditions imposed on a random field model for the error process. Moreover, computationally feasible algorithms are proposed for estimating regression coefficients and their standard errors. Finite‐sample properties of the proposed methods are investigated in a simulation study and comparison is made among different penalty functions. The methods are illustrated by an ecological dataset of landcover in Wisconsin. The Canadian Journal of Statistics 37: 607–624; 2009 © 2009 Statistical Society of Canada