基于Tri-training半监督学习的中文组织机构名识别*

针对中文组织机构名识别中的标注语料匮乏问题,提出了一种基于协同训练机制的组织机构名识别方法。该算法利用Tri-training学习方式将基于条件随机场的分类器、基于支持向量机的分类器和基于记忆学习方法的分类器组合成一个分类体系,并依据最优效用选择策略进行新加入样本的选择。在大规模真实语料上与co-training方法进行了比较实验,实验结果表明,此方法能有效利用大量未标注语料提高算法的泛化能力。     

基于不同序列特征值预测氧化还原酶辅酶类型的研究

如何有效提取蛋白质序列特征值,一直是生物信息学研究的重要任务.本文研究8种序列特征值提取方法,并考察它们在不同分类器中的表现,以用于预测氧化还原酶辅酶依赖类型.其中,氨基酸组成法效果最差,平均预测精度仅及64.96%;而将两性伪氨基酸组成和新氨基酸组成分布两种方法合并后,以支持向量机作为分类器时,其识别效果最佳,可达92.93%.此外,不同特征值的提取方法与分类器之间似乎有着一定的匹配关系,只有找到其间的最佳匹配,才能获得最佳的识别效果.     

基于DBN的多特征融合音乐情感分类方法

本文在音乐情感分类中的两个重要的环节：特征选择和分类器上进行了探索.在特征选择方面基于传统算法中单一特征无法全面表达音乐情感的问题,本文提出了多特征融合的方法,具体操作方式是用音色特征与韵律特征相结合作为音乐情感的符号表达;在分类器选择中,本文采用了在音频检索领域表现较好的深度置信网络进行音乐情感训练和分类.实验结果表明,该算法对音乐情感分类的表现较好,高于单一特征的分类方法和SVM分类的方法.     

基于PCA和CHMM的音频自动分类*

针对DHMM分类器对音频特征进行向量量化引起的误差及特征维数过多导致计算复杂度过大的问题,提出了一种新的基于PCA和CHMM的音频自动分类方法。它先将音频特征组成一个高维向量,然后使用PCA对这些高维向量进行降维,再使用CHMM分类器对降维后的特征进行分类。实验证明了PCA和CHMM音频分类的有效性。     

基于AE信号与优化SVM的刀具磨损状态识别

根据小波包变换理论,对刀具磨损声发射(AE)信号进行滤波和能量特征值提取.采用分步式扫描的方法对传统的盒计数法进行改进,并利用改进的盒计数法计算滤波后信号的广义分形维数特征值.以上述提取的特征值为备选特征,采用支持向量机(SVM)作为分类器,利用量子遗传算法(QGA)首先对分类器的输入特征进行筛选,之后对分类器的模型参数进行优化.利用优化后的分类器对测试样本进行分类,测试结果表明,该方法可以对刀具磨损状态进行有效识别.     

基于小波变换和支持向量机的音频分类

音频特征提取是音频分类的基础,而音频分类又是内容的音频检索的关键。综合分析了语音和音乐的区别性特征,提出一种基于小波变换和支持向量机的音频特征提取和分类的方法,用于纯语音、音乐、带背景音乐的语音以及环境音的分类,并且评估了新特征集合在SVM分类器上的分类效果。实验结果表明,提出的音频特征有效、合理,分类性能较好。     

基于支持向量机的多类音频分类

研究一种用支持向量机(SVM)进行多类音频分类的方法,其中引入增广两类分类法(AB法)设计多类分类器。该算法把音频分为四类:音乐、纯语音、带背景音的语音和典型的环境音,并分析了这几类音频的八个区别性特征,包括修正低能量成分比率(MLER)和修正基频(MPF)两个新特征以及频域总能量、子带能量、频率中心等其它六个基本特征,综合考察了不同特征集在基于SVM分类器中的分类精度。实验结果表明,提取的音频特征有效,基于SVM的多类音频分类效果良好。     

一种基于内容的音频流二级分割方法

基于内容的音频流分割是多媒体数据分析领域中的一个十分重要和困难的问题．目前大多数传统的音频流分割方法是基于小尺度音频分类的，但是这类分割方法普遍存在虚假分割点过多的缺点，严重影响了实际应用的效果．作者的研究表明，大尺度音频片段的分类正确率要明显高于小尺度音频片段的分类正确率，并且这个趋势与分类器选择无关．基于这个事实和减少虚假分割点的目的，作者提出了一种新的音频流分割方法．首先，采用基于大尺度音频分类的分割方法对音频流进行粗分割，以减少虚假分割点；然后定义了分割点评价函数，并利用它在边界区域中进一步精确定位分割点．实验结果表明这种音频流分割方法可以比较精确地获取分割点位置，同时将虚假分割点减少到传统方法的四分之一．     

基于SVM的音频分类系统设计及实现

分析音频时域特征及提取方法,研究基于支持向量机的语音分类系统流程、分类系统架构以及SVM语音分类器的设计,并进行了相关实验。结果表明,设计的基于SVM的音频分类系统能够有效地对音频进行分类,平均识别准确率达到90%以上。     

音乐和歌词融合的歌曲情感分类研究

为更好地对歌词进行情感分类,提出一种改进的基于类间差别的CHI特征选择方法。该方法可单独用于歌词情感特征提取,将选取的特征应用于支持向量机分类器中,融合音频特征与利用改进CHI方法选择的歌词特征对歌曲进行情感分类。实验结果表明,融合后的特征可以取得比任何单一种类特征更好的分类效果。     

Voice-Based Gender Identification in Multimedia Applications

In the context of content-based multimedia indexing gender identification based on speech signal is an important task. In this paper a set of acoustic and pitch features along with different classifiers are compared for the problem of gender identification. We show that the fusion of features and classifiers performs better than any individual classifier. Based on such conclusions we built a system for gender identification in multimedia applications. The system uses a set of Neural Networks with acoustic and Pitch related features.90% of classification accuracy is obtained for 1 second segments and with independence to the language and the channel of the speech. Practical considerations, such as the continuity of speech and the use of mixture of experts instead of one single expert are shown to improve the classification accuracy to 93%. When used on a subset of the Switchboard database, the classification accuracy attains 98.5% for 5 seconds segments.     

Speaker identification of whispering speech: an investigation on selected timbrel features and KNN distance measures

Speaker identification from the whispered speech is of great importance in the field of forensic science as well as in many other applications. Whispered speech shows many changes in the characteristics to its neutral counterpart. Hence the task of identification becomes difficult. This paper presents the use of only well-performing timbrel features selected by Hybrid selection method and effect of distance measures used in KNN classifier on the identification accuracy. The results using timbrel features are compared with MFCC features; the accuracy with the former is observed higher. KNN classifier with most probable distance function suitable for a whispered database like Euclidean and City-block are also compared. The combination of timbrel features and KNN classifiers with city block distance function have reported the highest identification accuracy.     

Improving BCI-based emotion recognition by combining EEG feature selection and kernel classifiers

Current emotion recognition computational techniques have been successful on associating the emotional changes with the EEG signals, and so they can be identified and classified from EEG signals if appropriate stimuli are applied. However, automatic recognition is usually restricted to a small number of emotions classes mainly due to signal’s features and noise, EEG constraints and subject-dependent issues. In order to address these issues, in this paper a novel feature-based emotion recognition model is proposed for EEG-based Brain–Computer Interfaces. Unlike other approaches, our method explores a wider set of emotion types and incorporates additional features which are relevant for signal pre-processing and recognition classification tasks, based on a dimensional model of emotions: Valenceand Arousal. It aims to improve the accuracy of the emotion classification task by combining mutual information based feature selection methods and kernel classifiers. Experiments using our approach for emotion classification which combines efficient feature selection methods and efficient kernel-based classifiers on standard EEG datasets show the promise of the approach when compared with state-of-the-art computational methods.     

Particle swarm optimisation based AdaBoost for object detection

This paper proposes a new approach to using particle swarm optimisation (PSO) within an AdaBoost framework for object detection. Instead of using exhaustive search for finding good features to be used for constructing weak classifiers in AdaBoost, we propose two methods based on PSO. The first uses PSO to evolve and select good features only, and the weak classifiers use a simple decision stump. The second uses PSO for both selecting good features and evolving weak classifiers in parallel. These two methods are examined and compared on two challenging object detection tasks in images: detection of individual pasta pieces and detection of a face. The experimental results suggest that both approaches can successfully detect object positions and that using PSO for selecting good individual features and evolving associated weak classifiers in AdaBoost is more effective than for selecting features only. We also show that PSO can evolve and select meaningful features in the face detection task.     

An extreme learning machine approach for speaker recognition

Over the last two decades, automatic speaker recognition has been an interesting and challenging problem to speech researchers. It can be classified into two different categories, speaker identification and speaker verification. In this paper, a new classifier, extreme learning machine, is examined on the text-independent speaker verification task and compared with SVM classifier. Extreme learning machine (ELM) classifiers have been proposed for generalized single hidden layer feedforward networks with a wide variety of hidden nodes. They are extremely fast in learning and perform well on many artificial and real regression and classification applications. The database used to evaluate the ELM and SVM classifiers is ELSDSR corpus, and the Mel-frequency Cepstral Coefficients were extracted and used as the input to the classifiers. Empirical studies have shown that ELM classifiers and its variants could perform better than SVM classifiers on the dataset provided with less training time.     

Implementation of Hybrid Deep Reinforcement Learning Technique for Speech Signal Classification

Classification of speech signals is a vital part of speech signal processing systems. With the advent of speech coding and synthesis, the classification of the speech signal is made accurate and faster. Conventional methods are considered inaccurate due to the uncertainty and diversity of speech signals in the case of real speech signal classification. In this paper, we use efficient speech signal classification using a series of neural network classifiers with reinforcement learning operations. Prior classification of speech signals, the study extracts the essential features from the speech signal using Cepstral Analysis. The features are extracted by converting the speech waveform to a parametric representation to obtain a relatively minimized data rate. Hence to improve the precision of classification, Generative Adversarial Networks are used and it tends to classify the speech signal after the extraction of features from the speech signal using the cepstral coefficient. The classifiers are trained with these features initially and the best classifier is chosen to perform the task of classification on new datasets. The validation of testing sets is evaluated using RL that provides feedback to Classifiers. Finally, at the user interface, the signals are played by decoding the signal after being retrieved from the classifier back based on the input query. The results are evaluated in the form of accuracy, recall, precision, f-measure, and error rate, where generative adversarial network attains an increased accuracy rate than other methods: Multi-Layer Perceptron, Recurrent Neural Networks, Deep belief Networks, and Convolutional Neural Networks.     

A new feature constituting approach to detection of vocal fold pathology

In the last two decades, non-invasive methods through acoustic analysis of voice signal have been proved to be excellent and reliable tool to diagnose vocal fold pathologies. This paper proposes a new feature vector based on the wavelet packet transform and singular value decomposition for the detection of vocal fold pathology. k-means clustering based feature weighting is proposed to increase the distinguishing performance of the proposed features. In this work, two databases Massachusetts Eye and Ear Infirmary (MEEI) voice disorders database and MAPACI speech pathology database are used. Four different supervised classifiers such as k-nearest neighbour (k-NN), least-square support vector machine, probabilistic neural network and general regression neural network are employed for testing the proposed features. The experimental results uncover that the proposed features give very promising classification accuracy of 100% for both MEEI database and MAPACI speech pathology database.     

Utilizing 3D flow of points for facial expression recognition

This paper presents an approach to recognize Facial Expressions of different intensities using 3D flow of facial points. 3D flow is the geometrical displacement (in 3D) of a facial point from its position in a neutral face to that in the expressive face. Experiments are performed on 3D face models from the BU-3DFE database. Four different intensities of expressions are used for analyzing the relevance of intensity of the expression for the task of FER. It was observed that high intensity expressions are easier to recognize and there is a need to develop algorithms for recognizing low intensity facial expressions. The proposed features outperform difference of facial distances and 2D optical flow. Performances of two classifiers, SVM and LDA are compared wherein SVM performs better. Feature selection did not prove useful.