多台系统异步可靠性增长模型及其统计分析

在各单台系统Weibull过程的可靠性增长假设条件下,建立了一种多台系统异步可靠性增长模型,并给出了可靠性增长试验数据的统计分析方法,包括模型参数的点估计、区间估计、系统MTBF估计、增长趋势检验及模型拟合优度检验等.较好地解决了不同步可靠性增长试验数据的统计分析问题.     

支持向量机的研究与发展

支持向量机是一种新型机器学习方法。是在统计学习理论基础上发展起来的一种新的数据挖掘方法,并已广泛应用于模式识别与回归分析。已成为国际机器学习界的研究热点。笔者主要对其基本原理与研究发展情况进行了探讨和研究。     

有关图书馆社会责任问题的统计研究

基于CNKI中国学术期刊全文数据库,统计了近30年来有关图书馆社会责任研究的论文。通过统计论文发表的年代、刊物、作者、关键词等,分析出不同时代图书馆社会责任的研究主要内容,从而比较出哪些刊物、哪些作者、哪个年代、哪些问题是这方面研究的主要关注点。     

Improving moving average trading rules with boosting and statistical learning methods

We present a system for combining the different types of predictions given by a wide category of mechanical trading rules through statistical learning methods (boosting, and several model averaging methods like Bayesian or simple averaging methods). Statistical learning methods supply better out‐of‐sample results than most of the single moving average rules in the NYSE Composite Index from January 1993 to December 2002. Moreover, using a filter to reduce trading frequency, the filtered boosting model produces a technical strategy which, although it is not able to overcome the returns of the buy‐and‐hold (B&H) strategy during rising periods, it does overcome the B&H during falling periods and is able to absorb a considerable part of falls in the market. Copyright © 2008 John Wiley & Sons, Ltd.     

Adaptive SPC monitoring scheme for DOE-based APC

Automatic process control （APC） based on design of experiment （DOE） is a cost-efficient approach for variation reduction. The process changes both in mean and variance owing to online parameter adjustment make it hard to apply traditional SPC charts in such DOE-based APC applied process. An adaptive SPC scheme is developed, which can better track the process transitions and achieve the possible SPC run cost reduction when the process is stable. The control law of SPC parameters is designed by fully utilizing the estimation properties of the process model instead of traditionally using the data collected from the production line. An example is provided to illustrate the proposed adaptive SPC design approach.     

基于非负矩阵分解新的人脸识别方法

非负矩阵分解是一个新的特征提取方法,基于非矩阵分解的理论,提出了具有正交性的投影轴的计算方法和具有统计不相关性的投影轴的计算方法。与原非负矩阵分解方法,提出的方法在某种程度上是降低了特征矢量之间的统计相关性,并且提高识别率。通过在ORL人脸库和YALE人脸库上进行实验,结果表明提出的两种特征提取方法在识别率方面整体上好于原非负矩阵分解特征提取(NMF)方法,甚至超过主成分分析(PCA)法。     

大气压下氦/氮射频放电冷等离子体特性

大气压射频辉光放电冷等离子体由于摆脱了真空腔的限制,在生物医学、电子工业、国防等领域有非常广阔的应用前景。为了拓展等离子体形成气体的种类,降低该技术的应用成本,对大气压下纯氮射频放电进行了研究。实验中采用13.56MHz射频电源和裸露的平板电极在大气压下实现了纯氮射频辉光放电,并比较了纯氦、纯氮和氦-氮混合气体条件下的放电特性。实验结果表明,大气压条件下,纯氦辉光放电具有两个稳定的放电模式(α模式和γ模式),而纯氮目前则只能稳定地工作在γ放电模式。     

数据删除模型与均值漂移模型的等价性推广

在普通的线性回归模型中,数据删除模型与均值漂移模型是具有等价性的,文章利用线性模型的最小二乘参数估计方法,将此等价性推广至具有附加信息的线性模型中.     

RM-structure alignment based statistical machine translation model

A novel model based on structure alignments is proposed for statistical machine translation in this paper. Meta-structure and sequence of meta-structure for a parse tree are defined. During the translation process, a parse tree is decomposed to deal with the structure divergence and the alignments can be constructed at different levels of recombination of meta-structure （RM）. This method can perform the structure mapping across the sub-tree structure between languages. As a result, we get not only the translation for the target language, but sequence of meta-stmctu .re of its parse tree at the same time. Experiments show that the model in the framework of log-linear model has better generative ability and significantly outperforms Pharaoh, a phrase-based system.     

基于最大流原理的湖泊系统富营养化新模型

针对目前现有的湖泊富营养化模型的不足,以最大流原理为基础,以自组织特征映射神经网络(SOM)为算法实现手段,从复杂系统结构演化的角度提出了一个新的湖泊系统的富营养化模型;进而使用该模型对我国10个湖泊进行了富营养化评价并和以往的评价方法作了详细比较,结果表明该方法具有较好的合理性和可操作性。由于该模型从一定程度上体现了湖泊富营养化系统的演化动力学机理和湖泊系统时空演变特性,因此,不仅在评价上有较大的优越性,在湖泊富营养化发展变化状态的预测上也具有潜力。