Neural network (NN) designed for challenging machine learning tasks is in general a highly nonlinear mapping that contains massive variational parameters. High complexity of NN, if unbounded or unconstrained, might unpredictably cause severe issues including over-fitting, loss of generalization power, and unbearable cost of hardware. In this work, we propose a general compression scheme that significantly reduces the variational parameters of NN by encoding them to deep automatically-differentiable tensor network (ADTN) that contains exponentially-fewer free parameters. Superior compression performance of our scheme is demonstrated on several widely-recognized NN's (FC-2, LeNet-5, AlextNet, ZFNet and VGG-16) and datasets (MNIST, CIFAR-10 and CIFAR-100). For instance, we compress two linear layers in VGG-16 with approximately $10^{7}$ parameters to two ADTN's with just 424 parameters, where the testing accuracy on CIFAR-10 is improved from $90.17 \%$ to $91.74\%$. Our work suggests TN as an exceptionally efficient mathematical structure for representing the variational parameters of NN's, which exhibits superior compressibility over the commonly-used matrices and multi-way arrays.
翻译:为应对具有挑战性的机器学习任务而设计的神经网络(NN)本质上是一种包含海量变分参数的高度非线性映射。若缺乏约束或限制,神经网络的高复杂度可能导致不可预测的严重问题,包括过拟合、泛化能力丧失及高昂的硬件成本。本研究提出一种通用压缩方案,通过将神经网络变分参数编码至深度可自动微分张量网络(ADTN)中,实现指数级减少自由参数。该方案在多个广泛认可的神经网络模型(如FC-2、LeNet-5、AlexNet、ZFNet和VGG-16)及数据集(MNIST、CIFAR-10和CIFAR-100)上展现出卓越的压缩性能。例如,我们将VGG-16中约含$10^{7}$个参数的两个线性层压缩为仅含424个参数的两个ADTN,同时在CIFAR-10上的测试准确率从$90.17\%$提升至$91.74\%$。本研究表明,张量网络(TN)作为表征神经网络变分参数的极其高效的数学结构,相较常规矩阵与多维数组具有更优越的可压缩性。