[1]钱冬,王蓓,张涛,等.结合Copula理论与贝叶斯决策理论的分类算法[J].智能系统学报编辑部,2016,11(1):78-83.[doi:10.11992/tis.201509011]
QIAN Dong,WANG Bei,ZHANG Tao,et al.Classification algorithm based on Copula theory and Bayesian decision theory[J].CAAI Transactions on Intelligent Systems,2016,11(1):78-83.[doi:10.11992/tis.201509011]
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《智能系统学报》编辑部[ISSN 1673-4785/CN 23-1538/TP] 卷:
11
期数:
2016年第1期
页码:
78-83
栏目:
学术论文—机器学习
出版日期:
2016-02-25
- Title:
-
Classification algorithm based on Copula theory and Bayesian decision theory
- 作者:
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钱冬1, 王蓓1, 张涛2, 王行愚1
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1. 华东理工大学信息科学与工程学院, 上海 200237;
2. 清华大学自动化系, 北京 100086
- Author(s):
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QIAN Dong1, WANG Bei1, ZHANG Tao2, WANG Xingyu1
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1. School of Information Science and Engineering, East China University of Science and Technology, Shanghai 200237, China;
2. Department of Automation, Tsinghua University, Beijing 100086, China
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- 关键词:
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机器学习; 贝叶斯决策理论; Copula理论; 核密度估计; 生物电信号
- Keywords:
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machine learning; Bayesian decision theory; Copula theory; kernel density estimation; physiological signals
- 分类号:
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TP391.4
- DOI:
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10.11992/tis.201509011
- 摘要:
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传统的贝叶斯决策分类算法易受类条件概率密度函数估计的影响,可能会对分类结果造成干扰。对此本文提出来一种改进的贝叶斯决策分类算法,即Bayesian-Copula判别分类器(BCDC)。该方法无需对类条件概率密度函数的形式进行假设,而是将Copula理论和核密度估计相结合进行函数构建,利用核密度估计平滑特征的概率分布,概率积分变换将特征的累计概率分布转化为均匀分布,Copula函数构建2个类别的边缘累积分布之间的相关性。随后,用极大似然估计方法确定Copula函数的参数,贝叶斯信息准则(BIC)用于选择最合适的Copula函数。通过生物电信号的仿真实验进行模型验证,结果表明相比传统的概率模型,提出的分类算法在分类精度和AUC两个性能指标上表现较好,鲁棒性更强,说明了BCDC模型充分利用Copula理论和核密度估计的优点,提高了估计的准确性和灵活性。
- Abstract:
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Traditional Bayesian decision classification algorithm is easily affected by the estimation of class-conditional probability densities, a fact that may result in incorrect classification results. Therefore, this paper proposes an improved classification algorithm based on Bayesian decision, i.e., Bayesian-Copula Discriminant Classifier (BCDC). This method constructs class-conditional probability densities by combining Copula theory and kernel density estimation instead of making assumptions on the form of class-conditional probability densities. Kernel density estimation is used to smooth the probability distribution of each feature. By performing probability integral transform, continuous distribution is converted to random variables having a uniform distribution. Then, Copula functions are used to construct the dependency structure between these probability distributions for two categories. Moreover, the maximum likelihood estimation is applied to determine the parameters of Copula functions, and two well-fitted Copula functions for two categories are selected based on Bayesian information criterion. The BCDC method was validated with experimental datasets of physiological signals. The obtained results showed that the proposed method outperforms other traditional methods in terms of classification accuracy and AUC as well as robustness. Moreover, it takes full advantage of Copula theory and kernel density estimation and improves the accuracy and flexibility of the estimation.
备注/Memo
收稿日期:2015-09-06;改回日期:。
基金项目:上海市科委科技创新行动计划-生物医药领域产学研医合作资助项目(12DZ1940903).
作者简介:钱冬,男,1990年生,硕士研究生,主要研究方向为机器学习、生物电信号;王蓓,女,1976年生,副研究员,主要研究方向为智能信息处理和模式分类、复杂系统及其在人工生命科学中的应用。曾参与国家自然科学基金、上海市科委科技创新行动计划等项目。发表学术论文50余篇,被SCI、EI检索30余篇;张涛,男,1969年生,教授,博士生导师,主要研究方向为控制理论及应用、信号处理、机器人控制等。主持或参与国家973项目、国家863项目、国家自然科学基金项目多项。曾获得教育部自然科学奖、军队科技进步奖、中国电子信息科学技术奖等。发表论文200余篇,其中被SCI检索40余篇,EI检索120余篇。
通讯作者:王蓓.E-mail:beiwang@ecust.edu.cn.
更新日期/Last Update:
1900-01-01