Information gain and divergence-based feature selection for machine learning-based text categorization     

Changki Lee  Gary Geunbae Lee 《Information processing & management》2006

Most previous works of feature selection emphasized only the reduction of high dimensionality of the feature space. But in cases where many features are highly redundant with each other, we must utilize other means, for example, more complex dependence models such as Bayesian network classifiers. In this paper, we introduce a new information gain and divergence-based feature selection method for statistical machine learning-based text categorization without relying on more complex dependence models. Our feature selection method strives to reduce redundancy between features while maintaining information gain in selecting appropriate features for text categorization. Empirical results are given on a number of dataset, showing that our feature selection method is more effective than Koller and Sahami’s method [Koller, D., & Sahami, M. (1996). Toward optimal feature selection. In Proceedings of ICML-96, 13th international conference on machine learning], which is one of greedy feature selection methods, and conventional information gain which is commonly used in feature selection for text categorization. Moreover, our feature selection method sometimes produces more improvements of conventional machine learning algorithms over support vector machines which are known to give the best classification accuracy.  相似文献   

基于Gabor小波的人脸识别系统的实现     

钟向阳 《嘉应学院学报》2005,23(3):74-78

给出了一种基于Gabor小波的人脸识别系统的实现.该方法先利用模板匹配法定位人脸图像的眼睛,然后经过标准化使图像具有相同的基准,其余特征点的搜索采用弹性图匹配方法;特征点的粗略位置根据训练集的人脸结构知识定位,然后使用弹性图簇的数据结构求得特征点的精确位置,当各特征点的精确位置定位后,人脸的Gabor Jets就可求得;样本图像的相似程度可用与人脸特征点对应的GaborJets作度量函数表达.  相似文献   

Ensemble learning HMM for motion recognition and retrieval by Isomap dimension reduction   总被引：1，自引：0，他引：1  

XIANG Jian WENG Jian-guang ZHUANG Yue-ting WU Fei 《浙江大学学报(A卷英文版)》2006,7(12):2063-2072

INTRODUCTION Now more and more motion capture systems are used to acquire realistic human motion data. Due to the success of the Mocap systems, realistic and highly detailed motion clips are commercially available and widely used for producing animations of human-like characters in a variety of applications, such as simu- lations, video games and animation files. Therefore an efficient motion data recognition and retrieval technique is needed to support motion data processing, such as mot…  相似文献   

A comparison of feature selection methods for an evolving RSS feed corpus   总被引：3，自引：0，他引：3  

Rudy Prabowo  Mike Thelwall   《Information processing & management》2006,42(6):1491

Previous researchers have attempted to detect significant topics in news stories and blogs through the use of word frequency-based methods applied to RSS feeds. In this paper, the three statistical feature selection methods: χ², Mutual Information (MI) and Information Gain (I) are proposed as alternative approaches for ranking term significance in an evolving RSS feed corpus. The extent to which the three methods agree with each other on determining the degree of the significance of a term on a certain date is investigated as well as the assumption that larger values tend to indicate more significant terms. An experimental evaluation was carried out with 39 different levels of data reduction to evaluate the three methods for differing degrees of significance. The three methods showed a significant degree of disagreement for a number of terms assigned an extremely large value. Hence, the assumption that the larger a value, the higher the degree of the significance of a term should be treated cautiously. Moreover, MI and I show significant disagreement. This suggests that MI is different in the way it ranks significant terms, as MI does not take the absence of a term into account, although I does. I, however, has a higher degree of term reduction than MI and χ². This can result in loosing some significant terms. In summary, χ² seems to be the best method to determine term significance for RSS feeds, as χ² identifies both types of significant behavior. The χ² method, however, is far from perfect as an extremely high value can be assigned to relatively insignificant terms.  相似文献   

简析“天津市治安维持会”的基本特征     

郭贵儒 《历史教学(高校版)》2008,(10)

1937年8月1日成立的天津市治安维持会,是日本侵略军在华北占领区最早扶植建立的傀儡组织之一。该伪组织遵照日军意旨,临时代行天津市府职权,在协助日军维持战争初期社会治安、镇压抗日活动等方面发挥了重要作用。本文分析天津市治安维持会的基本特征,如人员构成上的复杂性,政治上的对日依附性,行政上的准政府性,活动内容的示范性,组织上的过渡性等,以期读者对该伪组织的反动本质有进一步地了解和认识。  相似文献   

试论自主学习的理论依据、内涵与特征   总被引：11，自引：1，他引：11  

吴健强 《湖南广播电视大学学报》2004,(1):1-4

自主学习是学习主导自己的学习的主动建构的过程，是建立在教育的终身化、民主化和个性化等教育观上的一种教育策略。同时，自主学习也是一个相对意义上的概念，自主学习的自主不是绝对的。自主学习具有自主性、能动性、超前性、独立性、独特性、创造性等特点，自主性是自主学习的本质属性。  相似文献   

Feature selection based on mutual information and redundancy-synergy coefficient   总被引：2，自引：0，他引：2  

杨胜  顾钧 《Journal of Zhejiang University. Science. B》2004,(11)

INTRODUCTION Feature subset selection (FSS) is a data miningfundamental problem to select out relevant featuresand cast away irrelevant and redundant featuresfrom an original feature set (Liu and Motoda, 1998).If a feature subset satisfies the FSS measure and hasthe minimal size, it is regarded as the optimal fea-ture subset. Complete search strategy is the way toobtain an optimal feature subset. Branch and Bound(Narendra and Fukunaga, 1977), Focus (Almuallimand Dietterich, 199…  相似文献   

一种基于文本语义的网络敏感话题识别方法     

刘霁  周亚东  高峰  赵俊舟  薛峰 《深圳信息职业技术学院学报》2011,(3):33-37

网络已成为当今世界重要的信息载体,但是网络信息良莠不齐,对人们的生活造成了很多负面影响,因此,如何正确识别网络中的敏感话题,是当前网络舆情分析与监管的重要任务之一。本文以识别网络论坛中的敏感话题为目标,基于网络论坛文本在结构和表达上表现出的篇幅短、结构不完整、文字口语化等特性,将该类文本表示成基于向量空间模型的文本矩阵,并根据网络敏感话题具有先验知识和态度倾向性等特点,提出了基于倾向性词典的特征提取方法,可有效提高网络敏感话题识别的正确率,最后通过实验验证了这一改进的有效性,证实了本文的研究价值。  相似文献   

结合图像特征的平滑恢复技术     

王新霞  李国梁  孙伟 《教育技术导刊》2011,10(2)

图像恢复是数字图像处理领域内技术难度较大的项目。结构张量包含有图像的邻域结构特征,借助这些信息可在降噪的同时保持图像边缘的细节特征。运用此技术的算法在经典的图像恢复操作之后增加了对图像的平滑,降低了噪声的影响。在此基础上恢复的图像在峰值信噪比以及视觉效果上都有明显提高,基于卷积的快速运算也保证了算法的实时效果。  相似文献   

黄自歌曲钢琴伴奏之音乐特色研究     

赵洪斌 《毕节学院学报》2011,29(10):105-110

黄自为其创作的歌曲谱写的钢琴伴奏曲是其声乐作品的重要组成部分,它不仅能烘托旋律的意境,同时还能激发演唱者的表演欲望。其钢琴伴奏曲具有古典主义与浪漫主义风格相融合,诗、歌、乐完美结合,浓郁的民族风格等音乐特色。  相似文献