以相关性确定条件属性的概化决策树

在介绍了一些典型决策树分类算法的基础上,研究了一种基于相关性分析的决策树分类器。其主要思想是通过属性相关性来压缩训练集的大小并在建立决策树过程中采用此度量值来确定划分条件属性的顺序,通过阈值设定和处理简化了决策树的剪枝和优化过程,提高了处理的效率和规模。文章详细描述了算法的执行过程以及正确性证明和时间复杂性分析。     

基于非线性拟合方程的多变量决策树算法

根据数据属性间存在的线性相关和非线性相关影响决策树性能的特点,提出了一种用拟合回归建立决策树的算法,并利用这种相关性来提高分类能力.该算法选择了一个较优的属性子集,对此子集中的属性进行加权组合,用于构造决策树的节点,采用二次多项式来拟合两个属性间可能存在的相关性,从而构造出分类能力更强的决策树.研究中用UCI标准数据集对各种算法进行测试及比较,实验结果及分析表明此决策树算法具有良好性能.     

一种基于关联性度量的决策树分类方法

在介绍了一些典型的决策树分类算法的基础上,论述了所开发的面向先进制造企业的综合数据挖掘系统ScopeMiner中的决策树分类算法,该算法集中了ID3、C45和MedGen等典型算法的思想,并进行了改进·在建立决策树过程中采用关联性度量的计算来确定划分条件属性的顺序,通过阈值设定和处理简化了决策树的剪枝和优化过程,准确性高,分类速度快·系统已在某大型企业质量控制中得到了应用,取得了一定的经济和社会效益·文章详述了算法的执行过程、应用于冶金企业中的实例以及正确性证明和时间复杂性分析·     

基于决策属性挑选策略的改进的决策树算法

首先介绍了决策树算法的基本理论和建模过程及传统的决策属性的选取标准。然后介绍了传统的ID3决策树算法,并对常用决策树算法的优缺点进行了总结。以经典的决策树ID3模型为基础,对已有决策属性挑选策略进行了分析和总结,对决策属性挑选策略进行了改进,提出了基于"相关信息增益度"的决策属性挑选策略。该方法基于信息增益的计算标准,并通过引入属性间相关性关系对传统ID3算法"多值偏向性"的缺陷进行补偿。最后,将该方法应用于UCI数据中心的标准数据集合中,从分类精确度方面对改进的ID3算法和传统ID3算法进行比较和分析。通过实验分析,改进的E-ID3算法在分类精确度方面有更优秀的性能表现。     

基于粗糙集的RDT决策树生成算法的研究及应用

介绍了一种基于粗糙集理论的决策树生成算法--RDT(Rought Set Decision Tree).该方法运用了粗糙集理论中条件属性相对于决策属性的核,引入启发式条件计算并选择条件属性作为决策树的根结点或子结点.通过一个例子,与运用信息熵概念建立决策树的算法进行比较,结果表明采用RDT方法得到的决策树优于采用信息熵方法得到的决策树.还讨论了RDT与ID3算法对决策树精度和规模的影响,分析数据分类和知识发现的过程及特点.     

基于Rough集的决策树算法

针对基于Rough集的经典分类算法值约简算法等不适合大数据集的问题，提出了基于Rough集的决策树算法。采用一个新的选择属性的测度——属性分类粗糙度作为选择属性的启发式，该测度较Rough中刻画属性相关性的测度正区域等更为全面地刻画了属性分类综合贡献能力，并且比信息增益和信息增益率的计算更为简单。采取了一种新的剪枝方法——预剪枝，即在选择属性计算前基于变精度正区域修正属性对数据的初始划分模式，以更有效地消除噪音数据对选择属性和生成叶节点的影响．采取了一种与决策树算法高度融合的简单有效的检测和处理不相容数据的方法，从而使算法对相容和不相容数据都能进行有效处理。对UCI机器学习数据库中几个数据集的挖掘结果表明，该算法生成的决策树较ID3算法小，与用信息增益率作为启发式的决策树算法生成的决策树规模相当。算法生成所有叶节点均满足给定最小置信度和支持度的决策树或分类规则，并易于利用数据库技术实现，适合大数据集。     

属性约简的决策树分类算法对未成年人犯罪行为的分析

为获得影响未成年人犯罪程度的重要因素,在论证基于属性约简的决策树分类算法适于处理多属性大容量数据表的基础上,将该算法应用于未成年人犯罪行为的分析。分析过程首先从公安业务数据库中提取未成年人犯罪行为的相关信息并建立决策表,同时利用条件属性相对于决策属性的依赖关系进行属性约简,最终针对约简结果生成决策树获取规则,运行结果表...     

因素空间理论的决策树C4.5算法改进

针对决策树C4.5算法在处理数值型因素时比较复杂和分类精度不高等问题,在数据预处理过程中采用云变换进行连续因素离散化,给出了连续属性离散化的具体算法.利用因素空间理论给出一种构造决策树算法的新的启发式函数—分辨度,分析了算法的时间复杂度,证明其为多项式算法.研究结果表明:改进算法的测试准确率和效率均优于决策树算法.     

决策树算法及其改进

该文对传统的C 4.5决策树数据挖掘算法进行了改进,提出了一种双重熵平均决策树算法。传统的C 4.5决策树算法易出现无意义分枝,过度拟合等问题,针对该类问题,基于双重熵平均决策树算法,通过两次对样本子集熵平均值的计算、排序、合并处理,得到修正后的属性信息增益,并以此作为属性选择的依据,从而解决了传统C 4.5决策树算法可解释性差、易产生碎片等问题。     

数据挖掘中改进的C4.5决策树分类算法

针对传统C4.5决策树分类算法需要进行多次扫描,导致运行效率低的缺陷,提出一种新的改进C4.5决策树分类算法.通过优化信息增益推导算法中相关的对数运算,以减少决策树分类算法的运行时间;将传统算法中连续属性的简单分裂属性改进为最优划分点分裂处理,以提高算法效率.实验结果表明,改进的C4.5决策树分类算法相比传统的C4.5决策树分类算法极大提高了执行效率,减小了需求空间.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.