一种新的文法化简方法--树型算法

介绍了法化简中消除无用符号和无用产生式的树型算法，并通过实例予以验证。结果表明该方法具有简单直观、易于操作、构造方便等特点。     

土壤自动制图中的知识分类

以往的土壤图反映了土壤调查者在土壤制图时的思想模型，土壤制图单元与环境空间数据的关联可以被重新建模并用以推导形式上的调查规则。然后这些规则可以被用于对相同地区或其它类似地区的空间信息的重新解译。本研究将浙江省在龙游县已有的土壤调查图与地质图，土地利用现状图，DEM及其派生属性，双时相的TM卫星数据相结合，使用分类树方法提取了该地区的土壤制图规则，精度评价结果表明，这些规则对于研究区大部分土壤类型的预测是令人满意的。     

描述递归算法的有效工具──递归树

通过分析具体问题,抓住扩展条件和回溯条件两个关键点,画出递归树,由递归树写出相应的递归算法．     

Nullor网络一种新的拓扑分析方法

从节点导纳矩阵出发 ,定义了电压图、电流图 ,把节点导纳矩阵的代数余子式表示为电压图、电流图中完全树的树支导纳乘积之和     

基于粗集和决策树的Web文本分类规则抽取

本文根据CHI值原理、粗集理论和决策树原理,提出了一种抽取Web文本分类规则的新方法。决策树分类方法具有出色的数据分析效率和容易抽取、易于理解的分类规则等优势,但对于维数达成千上万维的分类问题很难应用。因此本文先根据CHI值选择每个文本类中对分类贡献大的若干词条,然后采用粗集理论方法对选择的特征进行进一步提取,这样得到维数较小的文本特征向量空间,最后再使用决策树进行分类,从而既保证了分类精度又可很容易地抽取出利于理解的文本分类规则。     

An NCME Instructional Module on Data Mining Methods for Classification and Regression

Data mining methods for classification and regression are becoming increasingly popular in various scientific fields. However, these methods have not been explored much in educational measurement. This module first provides a review, which should be accessible to a wide audience in education measurement, of some of these methods. The module then demonstrates using three real‐data examples that these methods may lead to an improvement over traditionally used methods such as linear and logistic regression in educational measurement.     

优美图的若干性质

刻划了优美图的基本性质 ,给出了某些优美图的具体标号。     

Risk assessment based on fault tree analysis for damaged pipe repair during operation in petrochemical plant

In petrochemical plant, the in-operation repairing is usually a repairing strategy with pressured inoperation repairing for avoiding huge economic losses caused by unplanned shutdown when some slight local leakage happens in pipes. This paper studies the effects of repairing strategies on the failure probability of the pipe systems in process industries based on the time-average fault tree approach, especially the in-operation repairing strategies including pressured in-operation repairing activities. The fault tree model can predict the effect of different repairing plans on the pipe failure probability, which is significant to the optimization of the repairing plans. At first pipes are distinguished into four states in this model, i.e., successive state, flaw state, leakage state and failure state. Then the fault tree approach, which is usually applied in the studies of dynamic equipment, is adopted to model the pipe failure. Moreover, the effect of pressured in-operation repairing is also considered in the model. In addition, this paper proposes a series of time-average parameters of the fault tree model, all of which are used to calculate node parameters of the fault tree model. At last, a practical case is calculated based on the fault tree model in a repairing activity of pipe thinning.     

改进的ID3算法及其在教育信息挖掘中的应用

为有效利用上海海事大学教学管理工作多年来积累的大量数据,对分类规则挖掘常用的ID3算法进行研究,结合教育信息的特点对ID3算法进行改进,以此为基础设计并实现了教育信息挖掘系统;利用所实现的系统对学生成绩和基本信息数据库进行挖掘分析,找出课程之间的相关性以及学生基本信息对学生就业方向的影响,并对挖掘结果进行比较分析,为学校的教学管理提供参考.     

以粒子蜂群网络建立高性能混凝土坍落度模型

以粒子蜂群算法(particle bee algorithm, PBA)结合神经网络(artificial neural network, NN),发展出一套能预测高性能混凝土(high performance concrete, HPC)坍落度模型的方法。以演化运算树(genetic operation tree, GOT)及倒传递网络(back propagation network, BPN)2种已发表的方法来比较其准确度。从模型的准确度可知,粒子蜂群网络(particle bee neural network, PBNN)模型预测的准确度高于GOT,但接近BPN的准确度;从参数的影响性可知,PBNN显示水、强塑剂、粗骨材、细骨材、粉煤灰及水泥添加量对于HPC坍落度的影响性大,而高炉矿渣粉用量对HPC坍落度并不敏感,显示各项材料对于坍落度的影响仍具备高度复杂性。