一种新的复杂细胞启发下的特征提取方法

鉴于V1区复杂细胞具有提取外界刺激不变本质的能力,设计了一个提取目标图像局部不变特征的方法.该方法首先使用提出的无监督算法(PCICA),从图像中学习出类似于复杂细胞感受野的滤波器集合.然后利用这些滤波器组成的复杂细胞描述子,提取目标图像各个位置的不变特征.最后对图像特征图进行分块统计,将各区域的直方图序列作为图像的最终描述.测试结果表明,PCICA具有类似于快速独立分量分析算法(FastICA)三阶收敛的特点,从图像中学习出的滤波器集合,表现出复杂细胞感受野的拓扑结构.这些滤波器对于局部图像的微小变化并不敏感,对于检测不变特征十分有利,并在MNIST手写体数据库上取得0.84%的识别错误率.     

MNIST邮政编码手写数字识别的研究

手写数字识别在很多领域都有着广泛的应用前景,论文研究了Gabor滤波器的特性及其特征提取的方法,PCM特征向量选择降低数据维数,SVM支持向量机的原理以及影响其性能的参数,并且克服了传统的维数灾难与过学习现象,用MNIST数据库做了仿真实验,交叉验证取得合适的SVM参数.实验表明,该方法取得了比较理想的结果,验证了SVM的多类分类方法,并与传统的一些分类方法做了比较分析.     

Hierarchical Covering Algorithm简

The concept of deep learning has been applied to many domains, but the definition of a suitable problem depth has not been sufficiently explored. In this study, we propose a new Hierarchical Covering Algorithm （HCA） method to determine the levels of a hierarchical structure based on the Covering Algorithm （CA）. The CA constructs neural networks based on samples＇ own characteristics, and can effectively handle multi-category classification and large-scale data. Further, we abstract characters based on the CA to automatically embody the feature of a deep structure. We apply CA to construct hidden nodes at the lower level, and define a fuzzy equivalence relation R on upper spaces to form a hierarchical architecture based on fuzzy quotient space theory. The covering tree naturally becomes from R. HCA experiments performed on MNIST dataset show that the covering tree embodies the deep architecture of the problem, and the effects of a deep structure are shown to be better than having a single level.