We study the convergence of recursive regularized learning algorithms in the reproducing kernel Hilbert space (RKHS) with dependent and non-stationary online data streams. Firstly, we study the mean square asymptotic stability of a class of random difference equations in RKHS, whose non-homogeneous terms are martingale difference sequences dependent on the homogeneous ones. Secondly, we introduce the concept of random Tikhonov regularization path, and show that if the regularization path is slowly time-varying in some sense, then the output of the algorithm is consistent with the regularization path in mean square. Furthermore, if the data streams also satisfy the RKHS persistence of excitation condition, i.e. there exists a fixed length of time period, such that each eigenvalue of the conditional expectation of the operators induced by the input data accumulated over every time period has a uniformly positive lower bound with respect to time, then the output of the algorithm is consistent with the unknown function in mean square. Finally, for the case with independent and non-identically distributed data streams, the algorithm achieves the mean square consistency provided the marginal probability measures induced by the input data are slowly time-varying and the average measure over each fixed-length time period has a uniformly strictly positive lower bound.

研究了具有依赖性和非平稳在线数据流的递归正则化学习算法在复制核希尔伯特空间中的收敛性。通过研究随机差分方程在核希尔伯特空间中的均方渐近稳定性和随机Tikhonov正则化路径的概念，证明了算法输出与正则化路径一致，并且满足一定条件下算法输出与未知函数一致。对于独立和非同分布的数据流情况，通过研究边缘概率测度和定期时间段的平均测度，证明了均方一致性的实现。

非平稳数据下再生核希尔伯特空间在线正则化统计学习的收敛条件