一种改进的基于密度聚类的支持向量机

运用OPTICS算法能发现任意形状的聚类,且对输入参数不敏感的优势,提出一种基于OPTICS密度聚类的支持向量机算法,通过对原始数据进行预处理,利用可达图得到约简样本代替原始训练样本用支持向量机进行训练,降低了SVM训练所需的时间及空间复杂度.实验表明,该方法在保持分类精度的同时,大大缩短了训练时间,提高了分类效率.     

一种最小测试代价约简的改进算法

传统属性约简的目标是在决策表中的所有条件属性中,选择一组分类代价最小的约简,算法构建了测试代价最小的约简.以往的测试代价约简算法查找成功率不够理想,性能不稳定,提出了一种改进的测试代价约简算法.通过运行2个UCI数据集实验,证明算法是有效的,并为提高测试代价约简算法性能提供了新途径.     

决策系统簇的平均代价敏感并行约简

大数据背景下，数据量呈指数级增长，三支决策在处理代价敏感问题时动态机制和稳定性不足.针对这个问题，结合F-粗糙集处理动态数据方面的优势，在代价敏感决策表簇中提出基于F-粗糙集和三支决策的平均代价敏感并行约简.首先，从平均决策代价和平均测试代价的角度，定义基于F-粗糙集和三支决策的并行约简；其次，设计基于F-粗糙集和三支决策的平均代价敏感并行约简算法.与基于分类的最小代价约简和基于类特定的最小代价约简比较，实验结果显示，基于F-粗糙集和三支决策的平均代价敏感并行约简可以更好地权衡误分类代价(决策代价)和测试代价，提高分类准确率.研究结果为研究动态决策和代价敏感提供一种新的研究方法和思路.     

一种基于密度的聚类算法实现

基于密度的聚类算法OPTICS是一种大规模数据库的聚类算法,它是基于核心对象和可达距离来实现的.对于每一个核心对象将其邻域内的所有对象按到该核心对象的可达距离进行排序,每次都选择1个到该核心对象具有最小的可达距离的对象进行信息更新.算法实现采用优先队列保存候选对象以加快处理速度,最后用UCI数据集对算法进行聚类效果测试,结果表明OPTICS算法对数据集产生一个基于密度的簇排序结构.     

决策粗糙集属性约简:一种局部视角方法

比较于经典粗糙集,决策粗糙集模型将代价问题考虑在内,为粗糙集的属性约简问题带来了新的挑战。尽管已有针对决策粗糙集的一些属性约简方法被提出,但这些约简标准都是基于所有决策类的,约束条件较为严格。为解决这一问题,从局部视角出发,针对单独的决策类提出了Local约简的思想。基于启发式算法求解约简的实验结果表明,相比于面向所有决策类的约简,Local约简可以获得更多的正域规则,同时也能够进一步降低约简中的属性数量。     

决策代价约简求解中的交叉验证策略

属性约简是粗糙集理论中的核心问题,其目的是剔除冗余属性以找到具有较好泛化能力的属性子集.在决策粗糙集理论中,决策代价经常被作为属性约简的约束条件.但值得注意的是,虽然基于决策代价的约简求解算法可以有效地降低训练样本集上的总决策代价,但其往往忽视了测试样本集上的总决策代价.为解决这一问题,利用交叉验证的基本思想,设计了以决策代价为约束条件的一种新的属性约简求解算法.在八个UCI数据集上的实验结果表明,相较于传统基于决策代价的约简求解算法,所提算法不仅能有效地降低训练集合和测试集合的总决策代价,而且找出的属性子集亦可以带来更好的分类性能.     

基于LDA模型和T-OPTICS算法的中文新闻话题检测

给出了一种针对大量新闻数据的话题检测方法.首先通过LDA(latent dirichlet allocation)模型从语义层面抽取新闻数据主题,有效降低数据分析维度,更合理地体现新闻主题特征.然后改进OPTICS(ordering point to identify the cluster structure)密度聚类算法,基于新闻话题的时间延续性给出了T-OPTICS算法.该算法继承了OPTICS算法对参数不敏感的特性,降低了参数选择对聚类结果的影响.改进了OPTICS算法中文本间相似度的计算方法,体现了话题的时间延续性.基于TDT4数据集的实验表明,该方法能够快速有效地发现新闻中的话题.     

基于类间依赖集约简的类簇测试用例生成算法

针对类簇中类间依赖关系以及类间消息交互产生的错误而导致测试冗余和测试遗漏的问题,提出一种类间依赖集约简的类簇测试用例生成算法。形式化定义了类间继承依赖、聚集依赖和关联依赖这3种依赖关系,建立类簇测试模型。定义类簇模式和用户(领域专家)解释集,并在用户解释集中依据每一个类对象的若干实例广义相等建立等价类,得出用户解释集幂集的1个子集即匹配划分集。据匹配消去算法求出类的最大匹配集,证明该集合就是所求类的最大非平凡非依赖集;提出一种交互差组合约简算法,计算类的最大非平凡非依赖集的补集,约简得到类的最小交叠集,并证明其就是类的最小非平凡依赖集,即类的组合测试用例;对其中每一个类的组合元素进行组合测试,并与其余类交互测试,得出类的交互测试序列。     

基于压缩差别矩阵的属性约简算法

影响基于差别矩阵的属性约简算法效率的主要因素有计算U/C等价类和差别矩阵的大小.为了解决差别矩阵大小影响属性约简算法计算效率,分析了基于差别矩阵的属性约简算法中差别矩阵定义的不足,重新定义了一种压缩差别矩阵,删除差别矩阵中大量的空元素和相同元素,从而进一步减少了差别矩阵元素的个数,并设计基于压缩差别矩阵的属性约简算法.对UCI及其他数据库进行仿真,实验结果表明该算法具有高效性.     

空间数据库中的一种约束组最近组查询方法

针对具有约束需求的空间数据库查询应用,定义了一种新查询——约束组最近组查询,并根据其约束特点深入研究了该查询的处理技术.首先,为了使组最近组查询结果的查询点数量满足约束条件,设计了一种约束聚簇算法,用来在查询初始阶段对查询点进行约束聚簇;其次,采用MBM和SHR方法在这些初始簇中计算初始查询结果;最后,通过迭代更新聚簇获得查询最优解,并提出一种剪枝策略来减少更新代价.实验结果证明了所提算法的有效性和实用性.     

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.     

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.     

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.     

A computer generator for randomly layered structures

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

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。     

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.     

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.     

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。     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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