Differentiable Architecture Search (DARTS) has attracted extensive attention due to its efficiency in searching for cell structures. However, DARTS mainly focuses on the operation search, leaving the cell topology implicitly depending on the searched operation weights. Hence, a problem is raised: can cell topology be well represented by the operation weights? The answer is negative because we observe that the operation weights fail to indicate the performance of cell topology. In this paper, we propose to Decouple the Operation and Topology Search (DOTS), which decouples the cell topology representation from the operation weights to make an explicit topology search. DOTS is achieved by defining an additional cell topology search space besides the original operation search space. Within the DOTS framework, we propose group annealing operation search and edge annealing topology search to bridge the optimization gap between the searched over-parameterized network and the derived child network. DOTS is efficient and only costs 0.2 and 1 GPU-day to search the state-of-the-art cell architectures on CIFAR and ImageNet, respectively. By further searching for the topology of DARTS' searched cell, we can improve DARTS' performance significantly. The code will be publicly available.

本文提出了一种Decouple the Operation and Topology Search（DOTS）的方法，该方法通过引入包含候选边的拓扑搜索空间实现了拓扑表示与操作权重的解耦，并且可以轻松扩展以支持搜索的单元中灵活数量的边。实验结果表明，DOTS对可微架构搜索是一种有效的解决方案。

DOTS: 可微分架构搜索中的操作与拓扑解耦