Image segmentation using voronoi polygons and MCMC, with application to muscle fibre images

We investigate a Bayesian method for the segmentation of muscle fibre images. The images are reasonably well approximated by a Dirichlet tessellation, and so we use a deformable template model based on Voronoi polygons to represent the segmented image. We consider various prior distributions for the parameters and suggest an appropriate likelihood. Following the Bayesian paradigm, the mathematical form for the posterior distribution is obtained (up to an integrating constant). We introduce a Metropolis-Hastings algorithm and a reversible jump Markov chain Monte Carlo algorithm (RJMCMC) for simulation from the posterior when the number of polygons is fixed or unknown. The particular moves in the RJMCMC algorithm are birth, death and position/colour changes of the point process which determines the location of the polygons. Segmentation of the true image was carried out using the estimated posterior mode and posterior mean. A simulation study is presented which is helpful for tuning the hyperparameters and to assess the accuracy. The algorithms work well on a real image of a muscle fibre cross-section image, and an additional parameter, which models the boundaries of the muscle fibres, is included in the final model.     

On the importance of being smooth

This paper makes the proposition that the only statistical analyses to achieve widespread popular use in statistical practice are those whose formulations are based on very smooth mathematical functions. The argument is made on an empirical basis, through examples. Given the truth of the proposition, the question ‘why should it be so?’ is intriguing, and any discussion has to be speculative. To aid that discussion, the paper starts with a list of statistical desiderata, with the view of seeing what properties are provided by underlying smoothness. This provides some rationale for the proposition. After that, the examples are considered. Methods that are widely used are listed, along with other methods which, despite impressive properties and possible early promise, have languished in the arena of practical application. Whatever the underlying causes may be, the proposition carries a worthwhile message for the formulation of new statistical methods, and for the adaptation of some of the old ones.     

F格上点式一致结构的刻画

证明了点式一致结构等价于点式完全正则性，构造了ＬＦ单位区间上一种自然的点式一致结构．     

Procrustes Shape Analysis of Planar Point Subsets

Consider a set of points in the plane randomly perturbed about a mean configuration by Gaussian errors. In this paper a Procrustes statistic based on the shapes of subsets of the points is studied, and its approximate distribution is found for small variations. We derive various properties of the distribution including the first two moments, a central limit result and a scaled χ²–-approximation. We concentrate on the independent isotropic Gaussian error case, although the results are valid for general covariance structures. We investigate triangle subsets in detail and in particular the situation where the population mean is regular (i.e. a Delaunay triangulation of the mean of the process is comprised of equilateral triangles of the same size). We examine the variance of the statistic for differently shaped regions and provide an asymptotic result for general shaped regions. The results are applied to an investigation of regularity in human muscle fibre cross-sections.     

论个体主体活动的客观性

个体主体性集中体现为自觉能动性。个体主体是主体性与客观性的有机统一。客观性是主体性得以确证的前提和条件。个体主体活动的客观性表现为受制约性、合规律性、重复性。如果进一步分析个体主体活动的本质特征———自觉能动性三方面具体内容的话 ,便可以更深刻地理解这一点     

大学生思想发展规律及启示思考

大学生是国家的宝贵财富,是未来中国特色社会主义现代化建设的中流砥柱。国家的富强、社会的发展、民族的振兴离不开大学生。然而,随着改革的不断深入,生产力不断提高,物质生活水平发生巨大改变,大学生作为先进的知识分子,他们的思想也在随着社会经济政治文化的发展发生巨大的变化。因此,全面准确地把握大学生的思想状况发展规律,立足实践实事求是地分析当代大学生的思想状况的发展轨迹,对于研究制定当代大学生培养策略是十分必要的。     

新形势下坚持全面从严治党的规律性研究

从严治党是中国共产党在长期执政条件下保持组织肌体的先进性和纯洁性,赢取广大人民群众的执政信任,拥有执政资格的必然要求。新的历史条件下坚持全面从严治党较之以往有其自身的规律,主要表现在必须增强管党治党的责任意识、必须恪守政党治理的威严性、必须把握政党治理的系统性、必须坚持政党治理的长期性、必须维护制度治党的权威性以及必须提升思想建党的有效性等六个层面。深入研究、探索和遵循新形势下全面从严治党的规律,对于更好地加强和改善执政党自身建设,重塑政治形象,提升执政党的战斗力、凝聚力和向心力,进一步巩固党的执政地位具有重大的现实意义和深远价值。     

国家治理现代化的内在逻辑——合规律性与合目的性的统一

国家治理现代化是社会主义现代化的题中之义,是合规律性与合目的性的统一。国家治理现代化是在中国共产党领导下,把马克思主义基本原理同中国具体实际相结合、同中华优秀传统文化相结合起来对社会主义现代化建设的一种探索,是一个不断超越、与时俱进的开放历史进程,深刻反映了中国共产党执政规律、社会主义建设规律和人类社会发展规律。这种规律性体现了在推进国家治理现代化过程中中国共产党的领导地位、作用和党的宗旨与初心、使命等,体现了国家治理现代化与社会主义建设之间以及与人类社会发展规律之间的内在逻辑关系。同时,国家治理现代化作为一种实践活动,在形成过程中还具有合目的性。我国国家治理现代化是以人民为中心为根本立场,以实现社会公平正义为核心价值取向,以全面实现国家治理体系和治理能力现代化为根本目的。这种目的性体现了推进国家治理现代化的主体和目标指向,体现了推进国家治理现代化坚持的基本价值准则和根本目的。总之,国家治理现代化是一个复杂的系统工程,其合规律性证明了国家治理现代化的科学性,合目的性证明了国家治理现代化的价值性,两者统一于中国特色社会主义伟大事业中。当今世界处于百年未有之大变局,面临的国内外风险挑战更为...     

高校教师专业发展的特点与规律

高校教师职业的特殊性决定了高校教师在专业发展过程中有着自己的特点和规律。在横向和纵向比较的基础上认为,高校教师专业发展最突出的特点体现为学术性、个体性、自主性;而通过经验总结和学理分析则认为,高校教师专业发展的规律主要有：生成——非线性规律、阶段——差异性规律、主动——互动性规律。     

Approximate entropy: Statistical properties and applications

ApEn, approximate entropy, is a recently developed family of parameters and statistics quantifying regularity (complexity) in data, providing an information-theoretic quantity for continuous-state processes. We provide the motivation for ApEn development, and indicate the superiority of ApEn to the K-S entropy for statistical application, and for discrimination of both correlated stochastic and noisy deterministic processes. We study the variation of ApEn with input parameter choices, reemphasizing that ApEn is a relative measure of regularity. We study the bias in the ApEn statistic, and present evidence for asymptotic normality in the ApEn distributions, assuming weak dependence. We provide a new test for the hypothesis that an underlying time-series is generated by i.i.d. variables, which does not require distribution specification. We introduce randomized ApEn, which derives an empirical significance probability that two processes differ, based on one data set from each process.