基于模糊互信息的多标签特征选择

多标签特征选择已成为处理多标签数据的重要方法之一.利用一种基于模糊互信息的多标签特征选择算法,通过模糊离散化,给出模糊联合熵和模糊条件熵吸模糊互信息的计算方式.将原先的互信息特征选择算法推广到模糊情形中,提出一种基于模糊互信息的多标签特征选择算法.最后在同一准则下,将模糊互信息与原先的互信息特征选择算法及其他几种经典的特征选择算法进行比较.实验表明,此方法在一定程度上效果优于其他特征选择算法,是一种有效的多标签分类问题的特征选择方法.     

基于自适应邻域互信息与谱聚类的特征选择

借鉴邻域粗糙集处理连续型数据的优势,为解决传统谱聚类算法需要人工选取参数的问题,提出基于自适应邻域互信息与谱聚类的特征选择算法。首先,定义各对象在属性下的标准差集合与自适应邻域集,给出自适应邻域熵、平均邻域熵、联合熵、邻域条件熵、邻域互信息等不确定性度量,利用自适应邻域互信息对特征与标签的相关性进行排序。然后,结合共享近邻自适应谱聚类算法,将相关性强的特征聚到同一特征簇内,使不同特征簇内的特征强相异。最后,使用最小冗余最大相关技术设计特征选择算法。在10个数据集上选择特征个数与分类精度的实验结果,验证了所提算法的有效性。     

基于层次标签数据的模糊决策树构造算法

决策树分类算法在数据挖掘领域是一种高效且应用普遍的分类算法。传统的决策树算法难以处理数据中存在的模糊性等不确定性信息,模糊决策树作为经典决策树在模糊集理论上的扩展,可有效克服这一缺陷。然而,现有的模糊决策树算法在处理具有层次结构的标签数据时,一般选取层次结构的某一层标签去分类数据,导致当分类准确率高时,标签不具体;标签具体时,分类准确率低,无法有效做到在分类准确率尽可能高的情况下,层次标签也尽可能具体。提出了一种基于层次标签数据的模糊决策树构造算法来解决以上问题,结合模糊ID3算法和层次信息增益思想对数据进行分类,并在构建过程中充分考虑了标签的层次。最后通过实验与传统模糊决策树算法对比,说明了所提算法的有效性。     

基于熵权法的过滤式特征选择算法

互信息过滤式特征选择算法往往仅局限于互信息这一度量标准.为规避采取单一的互信息标准的局限性,在互信息的基础上引入基于距离度量的算法RReliefF,从而得出更好的过滤式准则.将RReliefF用于分类任务,度量特征与标签的相关性;应用最大互信息系数(maximal information coefficient,MIC)度量特征与特征之间的冗余性、特征与标签的相关性;最后,应用熵权法为MIC和RReliefF进行客观赋权,提出了基于熵权法的过滤式特征选择算法(filtering feature selection algorithm based on entropy weight method, FFSBEWM).在13个数据集上进行对比实验,结果表明,FFSBEWM所选择的特征子集的平均分类准确率和最高分类准确率均优于其他对比算法.     

基于矩阵策略的不完备混合型数据增量式特征选择算法

特征选择是粗糙集理论在数据挖掘等领域中一种重要的应用,如何对动态变化的信息系统进行增量式特征选择是目前粗糙集理论研究的重点。在不完备混合型信息系统中,属性集的不断增加是信息系统动态变化的一种重要形式。首先在不完备混合型信息系统中引入邻域条件熵的概念,并且利用矩阵的方法去表示邻域条件熵;然后针对属性集动态增加的情形,提出矩阵形式的邻域条件熵增量式更新,并且基于这种增量式更新机制给出了相应的增量式特征选择算法;最后,UCI数据集的实验结果表明,所提出的增量式特征选择算法比非增量式特征选择算法具有更高的特征选择性能。     

基于图拉普拉斯的多标签类属特征选择

多标签特征选择能够有效去除冗余特征并提升分类精度, 是解决"维数灾难"问题的有效方法. 然而, 已有的多标签特征选择算法是对所有标签选择出相同的特征, 忽略了标签与特征之间的内在联系. 事实上, 每个标签都具有反映该标签特有属性的特征, 即类属特征. 提出一种基于图拉普拉斯的多标签类属特征选择(multi-label label-specific feature selection based on graph Laplacian, LSGL)算法. 对于每个类别标签, 基于拉普拉斯映射获得数据的低维嵌入, 再通过稀疏正则化获得数据空间到嵌入空间的投影矩阵, 接着通过分析矩阵系数确定每个标签相应的类属特征, 最后使用类属特征进行分类. 在 5 个公共多标签数据集上的多标签特征选择与分类实验结果证明了所提算法的有效性.     

基于图拉普拉斯的多标签类属特征选择

多标签特征选择能够有效去除冗余特征并提升分类精度,是解决“维数灾难”问题的有效方法.然而,已有的多标签特征选择算法是对所有标签选择出相同的特征,忽略了标签与特征之间的内在联系.事实上,每个标签都具有反映该标签特有属性的特征,即类属特征.提出一种基于图拉普拉斯的多标签类属特征选择(multi-label label-specific feature selection based on graph Laplacian,LSGL)算法.对于每个类别标签,基于拉普拉斯映射获得数据的低维嵌入,再通过稀疏正则化获得数据空间到嵌入空间的投影矩阵,接着通过分析矩阵系数确定每个标签相应的类属特征,最后使用类属特征进行分类.在5个公共多标签数据集上的多标签特征选择与分类实验结果证明了所提算法的有效性.     

基于新冗余度的特征选择方法

现有过滤式特征选择模型采用贪心策略结合互信息评价特征子集,容易陷入局部最优陷阱.考虑标签信息对冗余度的影响,利用一种改进的MIFS-U方法在给定标签的条件下衡量冗余度,采用基于分解的多目标优化框架结合引入多项式突变的差分进化算子进行全局搜索,避免搜索陷入局部最优.引入l₁正则化项来保证特征子集的稀疏性,并提出了新的特征选择算法MOEA/D-DEFS.实验阶段使用knn-5分类器来验证学习效果,并在多组来自不同领域的数据集上进行测试.结果表明,将特征选择视为多目标问题采用全局搜索策略搜索可以在特征子集维度和分类准确性方面提供更好的性能.     

半监督条件下的贝叶斯估计辐射源指纹特征识别

针对传统辐射源指纹识别过程中测试数据间的相关性往往被忽略,同时非合作条件下辐射源信号的识别训练标签数据不足的问题,提出了一种半监督条件下的贝叶斯估计辐射源指纹特征识别算法.首先,针对训练数据集不足的问题,在训练特征集提取阶段,利用半监督条件下的贝叶斯估计算法将有标签训练数据和无标签测试数据同时用于特征学习,以获取更为鲁棒的训练特征集.其次,为了有效利用测试数据之间的相关性,在测试特征集识别阶段,利用测试特征集与训练特征集的联合表征模型,将测试数据之间的相关性考虑在内,以提高识别算法的鲁棒性.实验结果表明:该算法在训练样本较少的情况下,依然可以获得较为鲁棒的分类识别效果.     

多角度标签结构和特征融合的多标签特征选择

特征选择是提高多标签分类性能的一种关键技术,一些特征选择算法在选择与标签相关的特征时没有从多个角度考虑标签结构,致使好的特征未能被选取,影响分类性能.为此,提出一种多角度标签结构和特征融合的多标签特征选择MLSFF.该算法的主要特点是:1)从三个角度考虑标签结构,提取三个重要的特征子集.2)融合提取的三个特征子集将整个...     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the