结合链接结构聚类的混沌粒子群网页分类规则抽取

网页分类器设计的核心是对原始分类数据集进行分类规则挖掘,本文提出了一种结合链接结构聚类的混沌粒子群网页分类规则获取算法．算法将聚类和分类结合起来进行分类规则提取：首先用基于K均值的聚类算法对一部分有代表性的链接结构数据聚类,进行类别自动标注,形成训练集;再用混沌粒子群算法对已标注类别的数据提取分类规则．实验结果表明,这种模式充分发挥了基于链接的分类方法受人为因素干扰最小的优点,减少了人工标注类别的工作量,同时提高分类的准确率和效率．     

基于改进XGBoost不平衡围岩超前分类方法的隧洞工程施工仿真研究

为了在围岩类别不平衡的条件下实现围岩类别有效判断,进而提高隧洞工程施工仿真准确性,基于改进极限梯度提升(XGBoost)不平衡围岩超前分类方法进行隧洞工程施工仿真研究。采用自动邻域确定合成过采样(AND-SMOTE)方法优化围岩类别不平衡性,并采用改进的XGBoost不平衡围岩超前分类模型进行围岩超前分类,进而优选仿真参数,提高仿真结果的准确性,其中,以模型交叉验证平均准确率为目标,采用哈里斯鹰优化(HHO)算法自动优化XGBoost超参数,以提高围岩分类精度。工程应用表明,相比未改进的XGBoost不平衡、KNN、SVC等6个模型,改进的XGBoost不平衡围岩超前分类模型分类精度更高;考虑围岩类别不平衡性后,改进的XGBoost不平衡围岩超前分类模型分类精度提高了8.6%;此外,基于围岩超前分类的隧洞工程施工仿真结果与实际进度的相对偏差相比传统仿真降低了11.3%,更符合工程实际。     

基于关键词的文本向量化与分类算法研究

针对自然语言文本集的预处理和分类问题,将词频统计方法(TF-IDF)引入到关键词提取(TextRank)算法中,并结合word2vec词向量化方法获得基于关键词的改进型文本向量化算法;进而,在k近邻算法中引入k值校正规则,并与该改进型算法结合获得文本集的改进型分类算法。利用格式和类别多样、数据量较大的文本集数据进行实验,结果表明,通过该方法可有效实现文档深层语义特征与浅层词频统计特征的融合,提取的文本关键词能较好表征文档的内容和类别,证明了获得的分类效果具有明显的优势。     

RBQENN算法在不平衡数据分类问题中的应用

针对kNN分类算法对不平衡数据进行分类可能偏向多数类的问题,提出了象限壳近邻分类算法。该算法仅选择测试样本象限方向上的最近邻的训练样本来判断其所属类别,从而有效地避免了kNN算法对选取k个最近邻训练样本时可能产生偏向多数类的问题。通过在UCI真实不平衡数据集上的实验,该文提出的分类算法在Recall、F-value和G-mean等评价标准明显优于传统的kNN分类算法。     

偏向自适应区间模糊C均值的遥感地物分类方法

遥感图像类内地物的异质性和类间地物的模糊性,造成地物类别归属的不确定性.模糊集理论能够对分类模糊现象进行有效的刻画,而区间值数据模型能够反映类别数据的不确定性.因此,本文结合区间值数据模型与模糊C均值算法,提出一种偏向自适应区间的模糊C均值算法,通过归一化类内均方差调整类别的整体区间宽度,利用偏向因子对数据进行有选择性的动态区间建模,进而增加类内紧凑性与类间边界可分性.实验结果表明,该方法可以有效地应用于SPOT5遥感数据的地物分类,整体分类精度和Kappa系数较现有流行的模糊分类方法均有较大的提升.     

面向不平衡数据集的SMOTENC-XGBOOST驾驶人交通安全评估模型

为深入挖掘驾驶人因素与交通事故之间的关系，提出一种基于SMOTENC和极端梯度提升(extreme gradient boosting, XGBoost)的驾驶人交通状态优劣分类算法。首先针对交通事故发生与否不平衡的特点，使用SMOTENC算法对数据进行上采样并在采样过程中加入随机扰动，解决了数据不平衡问题。然后使用Embedded算法结合L1正则化，通过模型评估完成对特征子集的选择。最后使用机器学习的方法将XGBoost算法用于执行数据的特征提取和分类过程。实验表明，在对驾驶人的交通状态进行综合评价的任务上，XGBoost模型的准确率为99.85%，相较于随机森林、支持向量机等对照组模型，提升了约1.12%-1.80%。除此之外，使用SMOTENC算法对数据不平衡问题进行处理后，通过混淆矩阵观察到模型对于好坏个体均具备较好的识别能力。     

上下文广告中的一种文本分类方法

针对文本分类中的交叉类别问题,提出一种基于传统潜在语义分析方法的新算法NLSA(new latentsemantic analysis)对网页进行文本分类.该方法可以将相关但是不同类别中的标签和非标签数据统一在一个概率模型中,通过研究两个类别的共有主题,在不同类别中转换知识来帮助目标文本进行分类.该方法可以最大化利用原有标签数据对新文本进行分类.实验证明:该算法能够显著提高交叉类别的文本分类性能,比传统的文本分类器有更好的性能.     

基于XGBoost模型的股骨颈骨折手术预后质量评分预测

将XGBoost算法推广到股骨颈骨折病例的临床数据中,并用Harris评分进行预测,得到了预测精度高、运算速度快的基于XGBoost算法的股骨颈骨折手术预后质量评分模型,证实了XGBoost算法解决医疗领域相关分类问题的有效性。     

基于多特征融合的混凝土结构表面病害图像分类算法

为提升混凝土表面开裂、露筋锈蚀和损伤3类病害图像分类效率与准确性,减少人工成本,提出了基于多特征融合的混凝土结构表面病害图像分类算法。该算法通过提取混凝土表面病害图像的纹理特征、灰度直方图特征、颜色特征,以支持向量机(SVM)为分类器,分别训练3类特征的病害图像分类模型,采用特征权重算法估计各个特征的权重系数,借助分类模型与权重系数估计病害图像类别划分的可信度值,根据最小误差原则将病害图像判定为可信度值最大的类别。设计了7组覆盖上述图像特征的特征融合方案,以2 400张病害图片为样本,训练了3种单一特征和4种多特征病害图像分类模型,并测试算法的准确性。结果表明:总体上,多特征融合分类模型对于混凝土表面病害图像分类准确率高于单一特征分类模型;基于多项式核函数,灰度+颜色+纹理特征融合分类模型分类效果最佳,平均分类准确率达到84%,较单一特征分类模型提升了7%;依赖于混凝土病害图像多特征的综合信息,灰度+颜色+纹理特征融合分类模型可将混凝土表面锈蚀和缺损的分类准确率提升至88%,多特征融合分类模型对于病害的分类判别稳定性显著优于单一特征分类模型。该研究可为混凝土表面病害图像分类提供有效方法,提升病害分类效率与准确性。     

基于聚类算法的电力制造业ERP数据分类

鉴于传统制造业企业仓储分类方法分类边界不明确、难以适应现代企业信息化发展趋势的问题,提出了基于聚类算法的ABC库存分类算法,提升了传统库存分类模型的分类精度和效率。以某电力制造业企业的库存产品数据为研究对象,结合聚类算法与ABC分类法提出了适用于实际研究场景的评价函数,并给出了新的基于k-means 算法的ABC分类法。采用该分类模型对库存环网柜产品进行分类,并基于ERP系统中存储的产品数据将库存环网柜产品分为A、B、C三类,根据分类结果对不同类别的环网柜产品采取不同的库存控制策略。研究结果表明,将数据挖掘算法应用于库存管理实现了企业库存管理决策的科学化和智能化。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to