一种具有对称性的变精度粗集模型

为了能够从不完备决策表(IDT)中进行知识发现和数据挖掘,提出一种新的具有对称性的双重可变精度限制容差关系粗集模型(VPLTRST).在该模型中,设定一对可调的参数使其作用于由IDT衍生出的限制容差关系,从而形成上下近似集.文中还提出新的在该模型下的知识依赖以及依赖度的定义,并以此作为依据进行知识约简.结合实例,清晰详实地展示了双重精度下如何获得所有知识约简并最终获得决策规则的全过程,具有很好的效果.     

基于k等价度容差关系的变精度粗糙集模型及其约简算法

针对k等价度容差关系,提出了一种基于k等价度容差关系的变精度粗糙集模型,该模型是变精度粗糙集模型在不完备信息系统中的拓展．在此基础上,定义了变精度粗糙集模型约简的概念,讨论了一种刻画属性重要性的新指标,提出了一种启发式约简算法．该算法能从搜索空间中不断地添加重要的属性,并且删除不重要的属性,从而降低了约简的时间复杂度．最后,通过实例说明该算法的有效性．     

限制容差关系的不完备可变粗糙集

针对不完备信息决策系统中信息引起的不相容性的问题,引进包含度,提出基于限制容差关系的可变粗糙集模型,并研究其相关性质.通过对限制容差关系的可变粗糙集模型和限制容差关系粗的糙集模型对比分析,结果表明:限制容差关系的可变粗糙集模型拥有更高的粗糙近似分类精度和粗糙近似分类似质量,通过实例说明该理论是可行的.     

基于一种新的量化容差关系的变精度粗糙集模型

提出了一种新的量化容差关系,建立了变精度粗糙集模型并提出了基于重要度的属性约简算法。新的模型考虑了决策属性值对条件属性值概率分布的影响并且具有一定噪声数据处理和错误分类容许能力。最后通过实例表明了该模型具有处理含有空值数据问题的能力。     

基于限制容差关系的粗糙集模型中近似集增量更新方法研究

基于限制容差关系的粗糙集模型可有效处理不完备信息系统, 目前对其研究仅限于静态数据.而在许多情况下数据是动态变化.因此, 研究基于限制容差关系的粗糙集模型下动态知识更新方法具有现实意义.本文给出了属性集变化时不完备信息系统在限制容差关系下近似集的增量更新方法.通过实例验证了方法的有效性, 可用来支持知识动态更新.     

双精度容差关系的粗糙集拓展模型及约简

研究了不完备区间值信息系统,提出新的改进模型.首先给出了基于相离度的相似度定义,使得模型可以处理属性值大多数相交但不具备包含关系以及含多个连续值的情形.其次,将容差关系进行拓展,提出了基于相似度和相似率的双精度容差关系,进而建立了适用于不完备区间值信息系统的粗糙集拓展模型.再次,为解决双精度容差关系在划分论域时的不足,提高近似精度,又求出了双精度极大相容类,据此来得到上下近似集,并给出了极大分类约简算法.最后,通过实例分析验证模型和算法的有效可行性.结果表明,所提出的粗糙集拓展模型适用的不完备区间值数据类型更为广泛,可用于处理一般的不完备区间值信息系统,拓展了粗糙集的适用范围.     

一种基于容差关系的辨识矩阵属性约简法

为有效处理灰色信息系统的属性约简问题．将粗糙集理论中有关属性约简的方法运用到灰色信息系统中。提出了一种基于容差关系的辨识矩阵属性约简法．这种方法并不对灰数进行白化．而是直接利用灰数的区间覆盖性定义一个基于贴近度的容差关系．并根据这个容差关系建立一个辨识矩阵对属性进行约简．避免了当灰数的取值分布信息缺乏时对灰数进行白化的主观性，是一种较为客观有效的灰色信息系统的属性约简法．     

一种新的不完备信息系统属性约简算法

针对不完备信息系统提出一种基于粗糙集理论的属性相对约简方法。利用粗糙集等价关系的扩展,即容差关系为基础提出容差关系相似矩阵的概念,通过引入广义决策函数的限制来解决不完备信息系统约简的不一致性问题,通过容差关系相似矩阵求不完备信息系统的核属性,利用属性在容差关系相似矩阵中出现的频率给出了属性重要度的计算公式,利用属性重要度为约简的启发式规则,并运用折半启发式算法减少扩展次数,提高约简速度。实验表明该方法简单、有效。     

决策信息系统协调性的关系矩阵表示

从矩阵视角研究不完备信息系统的知识表示和属性约简.首先,引入关系矩阵,基于容差关系提出不完备决策信息系统协调性判定方法.其次,利用关系矩阵求正域,并提出属性协调集的矩阵判定定理,从而给出一种保持正域不变的约简的新方法.最后,基于上述框架,给出属性重要性度,进一步提出一种属性约简的启发式算法,并通过分析和实例证明该方法的有效性.     

基于粗糙集理论不完备信息系统的数据挖掘

提出了一种基于推广的粗糙集理论直接在不完备信息系统上进行数据挖掘的方法，并给出了该方法的算法和实例．该方法利用粗糙集理论直接对不完备信息系统进行知识约简，然后根据获得的约简集建立知识层次树，利用规则的支持度阂值s0和置信度阈值c0从知识层次树的压缩搜索空间中提取不完备系统的规则集，该方法保持了原始数据和数据挖掘所获得的知识的真实性，另外，还提出了知识规则的上、下支持度，上、下置信度，规则粗糙度等概念，以便指导用户更好地利用数据挖掘所获得的知识．     

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.     

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.     

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.     

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.     

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.     

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that