词位标注汉语分词技术详解

近年来基于字的词位标注的方法极大地提高了汉语分词的性能,该方法将汉语分词转化为字的词位标注问题,借助于优秀的序列标注模型,基于字的词位标注汉语分词方法逐渐成为分词的主要技术路线。本文简要介绍了词位标注汉语分词的基本思想,探析了基于条件随机场实现词位标注汉语分词的机理,并对采用四词位标注集,使用CRF＋＋0.53工具包实现字串序列词位标注进行了详解。最后在Bakeoff2006的评测语料上进行了封闭测试。     

向量理论在概率论中的应用

通过在概率论中引入＂零变量＂概念,将向量空间理论应用于概率论的研究中,得到了同一样本空间Ω上的全体随机变量所成的集合是一向量空间的结论,并且证明了两个随机变量ξ,η的协方差即是向量ξ,η的内积〈ξ,η〉,继而得出同一样本空间Ω上的全体随机变量所成集合为一欧氏空间,从代数学的角度给予了概率论中的若干概念全新的解释.     

对随机变量的k-阶矩的讨论

文章从随机变量k-阶矩的定义出发,结合已有的定理推导出一些不等式,进而说明一些相关随机变量k-阶矩存在的条件。     

美国大学终身聘任后评审制政策的网络调查问卷设计及实施

近十多年来,终身聘任后评审政策在美国掀起了一场运动,引起了广泛关注.但目前国内研究还较少见,尤其定量研究更为缺乏.本文尝试通过网络调查问卷的定量研究来进行.从美国的研究/博士型、硕士型共862所大学总体中,采用分层随机抽样法,抽取公、私立大学共432所为样本,每所大学选择行政官员和教授各1位,直接进行跨国网上问卷调查.本研究表明,采用网络问卷调查法进行外国教育研究是一种成功的研究方式.     

浅谈政策效应对居民消费空间差异性的影响

采用面板随机效应模型,对我国东中西部政策效应对居民消费影响的空间差异性进行分析,根据研究结果发现：财政支出政策对居民消费的影响效果要远远大于财政收入政策效果;从城乡差异来看,财政政策对农村居民消费影响的效果较大,对城镇居民消费影响效果较小,这种特点特别表现在财政支出效果上;从区域差异上,财政支出政策对东部地区居民消费表现出更强的凯恩斯效应,对中西部地区居民消费则呈现更强的非凯恩斯效应,这种特征差异的原因可能是源于区域消费特征的差异;扩张财政政策在东中部效应显著,在西部紧缩性政策效果更为明显。     

Measurement Bias Detection Through Factor Analysis

Assessing the correctness of a structural equation model is essential to avoid drawing incorrect conclusions from empirical research. In the past, the chi-square test was recommended for assessing the correctness of the model but this test has been criticized because of its sensitivity to sample size. As a reaction, an abundance of fit indexes have been developed. The result of these developments is that structural equation modeling packages are now producing a large list of fit measures. One would think that this progression has led to a clear understanding of evaluating models with respect to model misspecifications. In this article we question the validity of approaches for model evaluation based on overall goodness-of-fit indexes. The argument against such usage is that they do not provide an adequate indication of the “size” of the model's misspecification. That is, they vary dramatically with the values of incidental parameters that are unrelated with the misspecification in the model. This is illustrated using simple but fundamental models. As an alternative method of model evaluation, we suggest using the expected parameter change in combination with the modification index (MI) and the power of the MI test.     

Diagnosing Global Case Influence on MAR Versus MNAR Model Comparisons

When missingness is suspected to be not at random (MNAR) in longitudinal studies, researchers sometimes compare the fit of a target model that assumes missingness at random (here termed a MAR model) and a model that accommodates a hypothesized MNAR missingness mechanism (here termed a MNAR model). It is well known that such comparisons are only interpretable conditional on the validity of the chosen MNAR model’s assumptions about the missingness mechanism. For that reason, researchers often perform a sensitivity analysis comparing the MAR model to not one, but several, plausible alternative MNAR models. In the social sciences, it is not widely known that such model comparisons can be particularly sensitive to case influence, such that conclusions drawn could depend on a single case. This article describes two convenient diagnostics suited for detecting case influence on MAR–MNAR model comparisons. Both diagnostics require much less computational burden than global influence diagnostics that have been used in other disciplines for MNAR sensitivity analyses. We illustrate the interpretation and implementation of these diagnostics with simulated and empirical latent growth modeling examples. It is hoped that this article increases awareness of the potential for case influence on MAR–MNAR model comparisons and how it could be detected in longitudinal social science applications.     

Accelerated matrix recovery via random projection based on inexact augmented Lagrange multiplier method

In this paper, a unified matrix recovery model was proposed for diverse corrupted matrices. Resulting from the separable structure of the proposed model, the convex optimization problem can be solved efficiently by adopting an inexact augmented Lagrange multiplier (IALM) method. Additionally, a random projection accelerated technique (IALM+RP) was adopted to improve the success rate. From the preliminary numerical comparisons, it was indicated that for the standard robust principal component analysis (PCA) problem, IALM+RP was at least two to six times faster than IALM with an insignificant reduction in accuracy; and for the outlier pursuit (OP) problem, IALM+RP was at least 6.9 times faster, even up to 8.3 times faster when the size of matrix was 2 000×2 000.     

分层抽样下多项选择敏感问题随机抽样调查方法及应用

目的是为多项选择敏感性问题提供科学的、精度更高的随机抽样调查方法及其统计量的计算公式,设计出多项选择敏感问题分层抽样下的随机抽样调查模型,并推导出在此模型下总体比例的估计量及其估计方差的计算公式,计算出敏感属性比例95％的置信区间。并在湖南城市学院本科学生考试作弊情况的实例调查中取得了信誉度较高的应用效果。     

疏影横斜水清浅 暗香浮动月黄昏——简评蒋冰的书法创作

蒋冰是近年来崛起的一位卓有成就的青年书法家。他的书法创作呈现出一种神清骨秀、高洁端庄、幽独超绝的气质风韵,具有极强的艺术审美价值。这与其深厚的文化底蕴、自然的创作理念、强烈的情感流露和执着的艺术追求密切相关。他的作品给当下书坛带来了一种不同凡响的清新气息。