Teaching metrology and quality in chemistry based on methods of mathematical statistics and e-learning

Chemistry students do not usually have the necessary background in mathematical statistics to study metrology and quality principles in chemistry. Even when the students have studied mathematical statistics, it is helpful to refresh their statistical knowledge, focusing on specific applications to metrology and quality in chemistry. Therefore, when planning a course for teaching metrology and quality it is important to achieve a harmonized interaction of metrological and quality issues with the supporting statistical issues. Additional possibilities for learning the relevant subjects originate from the Internet (e-learning). Such a lecture course developed and delivered during the five years since 2003 at the Hebrew University of Jerusalem is discussed in the paper.     

数字资源建设中电子图书采购策略研究

电子图书采购是数字资源建设中很重要的环节。为了加强电子图书采购的科学性和系统性,从图书馆、电子图书和书商等方面,介绍了电子图书采购的策略。     

金属压型板封闭施工工艺

从工艺步骤、安装条件、排板原则、锚固钉的选用及布置、封边及包角板制作及防水措施等方面介绍了金属压型板封闭的施工工艺。     

A theoretical study of the influence of dopants on the dehydrogenation properties of VH_2

Using the plane wave ultrasoft pseudopotential method based on the first-principles density functional theory(DFT),the influence on the electronic structure and dehydrogenation properties of VH2 doped with Zr,Cu and Zn has been studied.The results show that the negative heat of formation increases and the valence electron number at the Fermi level EF,N(EF) decreases in the Zr-doped model,indicating the higher stability of VH2 after Zr alloying.On the other hand,the negative heat of formation of VH2 decrease...     

大连民族学院图书馆2004-2009年藏书建设的统计分析

对大连民族学院图书馆2004-2009年馆藏图书增长量及图书借阅量进行了分类统计,并对借阅量前两位的图书进行子类细化统计分析。通过统计结果分析了读者的需求特点,以期为图书馆更科学合理地进行藏书建设和图书流通管理提供参考。     

An operational definition of learning

An operational definition offered in this paper posits learning as a multi-dimensional and multi-phase phenomenon occurring when individuals attempt to solve what they view as a problem. To model someone's learning accordingly to the definition, it suffices to characterize a particular sequence of that person's disequilibrium-equilibrium phases in terms of products of a particular mental act, the characteristics of the mental act inferred from the products, and intellectual and psychological needs that instigate or result from these phases. The definition is illustrated by analysis of change occurring in three thinking-aloud interviews with one middle-school teacher. The interviews were about the same task: “Make up a word problem whose solution may be found by computing 4/5 divided by 2/3.”     

Large deviations for Glauber dynamics of continuous gas

This paper is devoted to the large deviation principles of the Glauber-type dynamics of finite or infinite volume continuous particle systems.We prove that the level-2 empirical process satisfies the large deviation principles in the weak convergence topology,while it does not satisfy the large deviation principles in the T-topology.     

平均复本量预测模型研究

在确定采购复本量过程中，重点突出读者借阅行为的影响作用，根据借阅率与平均复本量之间相关关系，运用线性回归分析方法，预测未来2008-2009学年度20个大类图书平均复本量。目的是为了给采购复本量的确定提供参考。选取高校图书馆中具有代表性的H语言类图书为例，介绍平均复本量预测过程。     

Statistical Significance of Clustering Using Soft Thresholding

Clustering methods have led to a number of important discoveries in bioinformatics and beyond. A major challenge in their use is determining which clusters represent important underlying structure, as opposed to spurious sampling artifacts. This challenge is especially serious, and very few methods are available, when the data are very high in dimension. Statistical significance of clustering (SigClust) is a recently developed cluster evaluation tool for high-dimensional low sample size (HDLSS) data. An important component of the SigClust approach is the very definition of a single cluster as a subset of data sampled from a multivariate Gaussian distribution. The implementation of SigClust requires the estimation of the eigenvalues of the covariance matrix for the null multivariate Gaussian distribution. We show that the original eigenvalue estimation can lead to a test that suffers from severe inflation of Type I error, in the important case where there are a few very large eigenvalues. This article addresses this critical challenge using a novel likelihood based soft thresholding approach to estimate these eigenvalues, which leads to a much improved SigClust. Major improvements in SigClust performance are shown by both mathematical analysis, based on the new notion of theoretical cluster index (TCI), and extensive simulation studies. Applications to some cancer genomic data further demonstrate the usefulness of these improvements.