arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.11968cs.LGstat.ML
收藏

稀疏编码提高了神经动态规划的速度和效率,用于具有相关输入的最优控制任务

A sparse code increases the speed and efficiency of neuro-dynamic programming for optimal control tasks with correlated inputs

University of New England(新英格兰大学)

Peter N. Loxley

摘要:

神经科学中的稀疏编码被认为比感觉数据的其他神经表示提供了某些计算优势。为了探索这一观点,稀疏代码被用来表示自然图像的最优控制任务解决神经动态规划,其计算性能进行了研究。核心发现是,当线性网络的特征输入是相关的时,过完备稀疏代码以有效的方式增加了网络的存储容量,超过了具有相同大小输入的任何完整代码的可能性,并且还增加了学习网络权重的速度。一个完整的稀疏码被发现,以最大限度地提高记忆容量的线性网络的特征输入去相关变换的最小二乘问题的设计矩阵满秩之一。它还条件的最小二乘问题的海森矩阵,从而提高收敛到最优网络权重的速度。其他类型的去相关码也可以实现这一点。然而,过完备稀疏码被发现是近似去相关的,从相同大小的输入中提取大量近似去相关的特征,使其能够有效地增加内存容量,超过任何完整代码的可能:与使用相同输入的完整稀疏码相比,2.25倍的过完备稀疏码至少增加了一倍的内存容量。这被用于顺序学习,以存储网络中潜在的大量最优控制任务,同时使用分区表示避免灾难性遗忘,从而产生在每个分区中概括状态的成本去函数近似器。还讨论了稀疏码相对于密集码和局部码的优势。

英文摘要:

Sparse codes in neuroscience have been suggested to offer certain computational advantages over other neural representations of sensory data. To explore this viewpoint, a sparse code is used to represent natural images in an optimal control task solved with neuro-dynamic programming, and its computational properties are investigated. The central finding is that when feature inputs to a linear network are correlated, an over-complete sparse code increases the memory capacity of the network in an efficient manner beyond that possible for any complete code with the same-sized input, and also increases the speed of learning the network weights. A complete sparse code is found to maximise the memory capacity of a linear network by decorrelating its feature inputs to transform the design matrix of the least-squares problem to one of full rank. It also conditions the Hessian matrix of the least-squares problem, thereby increasing the rate of convergence to the optimal network weights. Other types of decorrelating codes would also achieve this. However, an over-complete sparse code is found to be approximately decorrelated, extracting a larger number of approximately decorrelated features from the same-sized input, allowing it to efficiently increase memory capacity beyond that possible for any complete code: a 2.25 times over-complete sparse code is shown to at least double memory capacity compared with a complete sparse code using the same input. This is used in sequential learning to store a potentially large number of optimal control tasks in the network, while catastrophic forgetting is avoided using a partitioned representation, yielding a cost-to-go function approximator that generalizes over the states in each partition. Sparse code advantages over dense codes and local codes are also discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑