Wang Hao, Feng Ruibin, Han Zi-Fa, Leung Chi-Sing
IEEE Trans Neural Netw Learn Syst. 2018 Aug;29(8):3870-3878. doi: 10.1109/TNNLS.2017.2731319. Epub 2017 Aug 15.
In the training stage of radial basis function (RBF) networks, we need to select some suitable RBF centers first. However, many existing center selection algorithms were designed for the fault-free situation. This brief develops a fault tolerant algorithm that trains an RBF network and selects the RBF centers simultaneously. We first select all the input vectors from the training set as the RBF centers. Afterward, we define the corresponding fault tolerant objective function. We then add an -norm term into the objective function. As the -norm term is able to force some unimportant weights to zero, center selection can be achieved at the training stage. Since the -norm term is nondifferentiable, we formulate the original problem as a constrained optimization problem. Based on the alternating direction method of multipliers framework, we then develop an algorithm to solve the constrained optimization problem. The convergence proof of the proposed algorithm is provided. Simulation results show that the proposed algorithm is superior to many existing center selection algorithms.
在径向基函数(RBF)网络的训练阶段,我们首先需要选择一些合适的RBF中心。然而,许多现有的中心选择算法是针对无故障情况设计的。本文提出了一种容错算法,该算法在训练RBF网络的同时选择RBF中心。我们首先从训练集中选择所有输入向量作为RBF中心。然后,我们定义相应的容错目标函数。接着,我们在目标函数中添加一个 -范数项。由于 -范数项能够迫使一些不重要的权重为零,因此可以在训练阶段实现中心选择。由于 -范数项不可微,我们将原问题表述为一个约束优化问题。基于乘子交替方向法框架,我们开发了一种算法来求解该约束优化问题。文中给出了所提算法的收敛性证明。仿真结果表明,所提算法优于许多现有的中心选择算法。