Yu Qiang, Ma Chenxiang, Song Shiming, Zhang Gaoyan, Dang Jianwu, Tan Kay Chen
IEEE Trans Neural Netw Learn Syst. 2022 Apr;33(4):1714-1726. doi: 10.1109/TNNLS.2020.3043415. Epub 2022 Apr 4.
Spiking neural networks (SNNs) are considered as a potential candidate to overcome current challenges, such as the high-power consumption encountered by artificial neural networks (ANNs); however, there is still a gap between them with respect to the recognition accuracy on various tasks. A conversion strategy was, thus, introduced recently to bridge this gap by mapping a trained ANN to an SNN. However, it is still unclear that to what extent this obtained SNN can benefit both the accuracy advantage from ANN and high efficiency from the spike-based paradigm of computation. In this article, we propose two new conversion methods, namely TerMapping and AugMapping. The TerMapping is a straightforward extension of a typical threshold-balancing method with a double-threshold scheme, while the AugMapping additionally incorporates a new scheme of augmented spike that employs a spike coefficient to carry the number of typical all-or-nothing spikes occurring at a time step. We examine the performance of our methods based on the MNIST, Fashion-MNIST, and CIFAR10 data sets. The results show that the proposed double-threshold scheme can effectively improve the accuracies of the converted SNNs. More importantly, the proposed AugMapping is more advantageous for constructing accurate, fast, and efficient deep SNNs compared with other state-of-the-art approaches. Our study, therefore, provides new approaches for further integration of advanced techniques in ANNs to improve the performance of SNNs, which could be of great merit to applied developments with spike-based neuromorphic computing.
脉冲神经网络(SNN)被认为是克服当前挑战的潜在候选者,比如人工神经网络(ANN)所面临的高功耗问题;然而,在各种任务的识别准确率方面,它们之间仍存在差距。因此,最近引入了一种转换策略,通过将训练好的ANN映射到SNN来弥合这一差距。然而,目前尚不清楚由此得到的SNN在多大程度上既能受益于ANN的准确率优势,又能受益于基于脉冲的计算范式的高效率。在本文中,我们提出了两种新的转换方法,即TerMapping和AugMapping。TerMapping是一种典型阈值平衡方法的直接扩展,采用双阈值方案,而AugMapping还额外引入了一种增强脉冲的新方案,该方案使用脉冲系数来承载在一个时间步长内出现的典型非此即彼脉冲的数量。我们基于MNIST、Fashion-MNIST和CIFAR10数据集检验了我们方法的性能。结果表明,所提出的双阈值方案能够有效提高转换后的SNN的准确率。更重要的是,与其他现有方法相比,所提出的AugMapping在构建准确、快速且高效的深度SNN方面更具优势。因此,我们的研究为进一步整合ANN中的先进技术以提高SNN的性能提供了新方法,这对于基于脉冲的神经形态计算的应用开发可能具有重要价值。