Journal of Computer Applications ›› 2015, Vol. 35 ›› Issue (7): 2101-2104.DOI: 10.11772/j.issn.1001-9081.2015.07.2101

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Integration algorithm of improved maximum a posteriori probability vector quantization and least squares support vector machine

ZHANG Jun, GUAN Shengxiao   

  1. School of Information Science and Technology, University of Science and Technology of China, Hefei Anhui 230027, China
  • Received:2015-02-12 Revised:2015-03-31 Online:2015-07-10 Published:2015-07-17

基于改进的最大后验概率矢量量化和最小二乘支持向量机集成算法

张俊, 关胜晓   

  1. 中国科学技术大学 信息科学技术学院, 合肥 230027
  • 通讯作者: 关胜晓(1964-),男,安徽合肥人,副教授,博士,主要研究方向:智能机器人、模式识别、嵌入式系统,guanxiao@ustc.edu.cn
  • 作者简介:张俊(1990-),男,安徽合肥人,硕士研究生,主要研究方向:说话人识别、关键词识别

Abstract:

In view of the current efficiency problem of speaker recognition system, this paper utilized the tactics of integration algorithm to put forward a new kind of speaker recognition system framework. The traditional Maximum A posteriori Probability Vector Quantization (VQ-MAP) algorithm only focuses on the average vector regardless of weight. In order to solve this problem, this paper put forward an improved algorithm based on VQ-MAP. The algorithm used weighted average vector instead of average vector. Moreover, Support Vector Machine (SVM) algorithm costs too much time, so Least Squares Support Vector Machine (LS-SVM) was used instead of SVM. Finally, in the speaker recognition system, this paper used the parameters calculated from the improved VQ-MAP algorithm as training set of LS-SVM. The experimental results show that, the modeling time of integration algorithm based on improved VQ-MAP and LS-SVM is about 40% less than that of traditional SVM algorithm when using the Radial Basis Function (RBF) kernel function and the sample of 40 people. As the threshold value is 1 and the test speech time is 4 s, compared to the traditional VQ-MAP and SVM algorithm, the deterrent rate is reduced by 1.1%, the false rejection rate is reduced by 2.9% and the recognition rate is increased by 3.9%. As the threshold value is 1 and the test speech time is 4 s, compared to the traditional VQ-MAP and LS-SVM algorithm, the deterrent rate is reduced by 3.6%, the false rejection rate is reduced by 2.7% and the recognition rate is increased by 4.4%. The results show that the integrated algorithm can improve the recognition rate effectively and reduce the operation time significantly, meanwhile reduce the deterrent rate and the false rejection rate.

Key words: Maximum A posteriori Probability (MAP), Least Squares Support Vector Machine (LS-SVM), weight, mean vector, speaker recognition

摘要:

针对目前说话人识别系统的效率问题,采用集成算法的策略,提出一种新的说话人识别系统框架。首先,考虑到传统的最大后验概率矢量量化(VQ-MAP)算法中只关注平均矢量而不考虑权重的问题,提出了改进的VQ-MAP算法,使用加权平均向量来代替平均向量;然后,由于支持向量机(SVM)算法相对耗时,故采用最小二乘支持向量机(LS-SVM)替代SVM算法;最后,在说话人识别系统中,利用改进的VQ-MAP算法所得参数集作为LS-SVM的训练样本。实验结果表明,基于改进的VQ-MAP和LS-SVM的集成算法,与传统的SVM算法相比,在均使用径向基函数(RBF)核函数时,对40人样本数据建模时间上减少接近40%;在阈值为1,测试语音时长为4 s时,与传统的VQ-MAP和SVM算法相比,误识率降低了1.1%,误拒率降低了2.9%,识别率提高了3.9%;在阈值为1,测试语音时长为4 s时,与传统的VQ-MAP和LS-SVM算法相比,误识率降低了3.6%,误拒率降低了2.7%,识别率提高了4.4%。结果表明,集成算法能够有效提高算法识别率,明显减少运算时间,同时降低误识率和误拒率。

关键词: 最大后验概率, 最小二乘支持向量机, 权重, 平均向量, 说话人识别

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