计算机应用 ›› 2016, Vol. 36 ›› Issue (3): 703-707.DOI: 10.11772/j.issn.1001-9081.2016.03.703

• 人工智能 • 上一篇    下一篇

基于半监督学习的动态神经网络结构设计

任红格, 李冬梅, 李福进   

  1. 华北理工大学 电气工程学院, 河北 唐山 063009
  • 收稿日期:2015-08-17 修回日期:2015-10-19 出版日期:2016-03-10 发布日期:2016-03-17
  • 通讯作者: 李冬梅
  • 作者简介:任红格(1979-),女,河北石家庄人,副教授,博士,主要研究方向:人工智能控制;李冬梅(1991-),女,河北邢台人,硕士研究生,主要研究方向:智能控制;李福进(1957-),男,河北唐山人,教授,博士,主要研究方向:自动控制。
  • 基金资助:
    国家自然科学基金资助项目(61203343);河北省自然科学基金资助项目(E2014209106)。

Dynamic neural network structure design based on semi-supervised learning

REN Hongge, LI Dongmei, LI Fujin   

  1. College of Electrical Engineering, North China University of Science and Technology, Tangshan Hebei 063009, China
  • Received:2015-08-17 Revised:2015-10-19 Online:2016-03-10 Published:2016-03-17
  • Supported by:
    This work is partially supported by the National Natural Science Foundation of China (61203343) and the Natural Science Foundation in Hebei Province (E2014209106).

摘要: 针对神经网络初始结构的设定依赖于工作者的经验、自适应能力较差等问题,提出一种基于半监督学习(SSL)算法的动态神经网络结构设计方法。该方法采用半监督学习方法利用已标记样例和无标记样例对神经网络进行训练,得到一个性能较为完善的初始网络结构,之后采用全局敏感度分析法(GSA)对网络隐层神经元输出权值进行分析,判断隐层神经元对网络输出的影响程度,即其敏感度值大小,适时地删减敏感度值很小的神经元或增加敏感度值较大的神经元,实现动态神经网络结构的优化设计,并给出了网络结构变化过程中收敛性的证明。理论分析和Matlab仿真实验表明,基于SSL算法的神经网络隐层神经元会随训练时间而改变,实现了网络结构动态设计。在液压厚度自动控制(AGC)系统应用中,大约在160 s时系统输出达到稳定,输出误差大约为0.03 mm,与监督学习(SL)方法和无监督学习(USL)方法相比,输出误差分别减小了0.03 mm和0.02 mm,这表明基于SSL算法的动态网络在实际应用中能有效提高系统输出的准确性。

关键词: 动态神经网络, 半监督学习, 全局敏感度分析法, 自适应能力, 敏感度值

Abstract: In view of the neural network's initial structure set depends on the workers experience and its adaptive ability is poor, a dynamic neural network structure design method based on Semi-Supervised Learning (SSL) algorithm was proposed. In order to get a more perfect performance of the initial network structure, the authors trained neural network based on semi-supervised learning method of using both tagged sample and unmarked sample, and judged the impact of the hidden layer neurons on the network output by using Global Sensitivity Analysis method (GSA). The optimal design of dynamic neural network structure was accomplished by cutting or increasing hidden layer neurons based on sensitivity size timely, and the convergence of the dynamic process was investigated. Theoretical analysis and Matlab simulation experiments show that the neural network hidden layer neurons based on Semi-Supervised Learning algorithm will change with training time, and the structure design of the dynamic network is accomplished. The application of hydraulic Automatic Gauge Control (AGC) system, about 160 s later, the system output is becoming stable, and the output error is as small as about 0.03 mm, and compared with Supervised Learning (SL) method and UnSupervised Learning (USL) method, the output error reduces by 0.03 mm and 0.02 mm respectively, which indicate that dynamic network based on SSL algorithm effectively improve the precision of the system output in actual applications.

Key words: dynamic neural network, Semi-Supervised Learning (SSL), Global Sensitivity Analysis (GSA), adaptive ability, sensitivity size

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