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arXiv 1506.03338cs.LGstat.ML
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神经自适应序贯蒙特卡罗

Neural Adaptive Sequential Monte Carlo

University of Cambridge(剑桥大学);MPI for Intelligent Systems(马克斯·普朗克智能系统研究所)

Shixiang Gu, Zoubin Ghahramani, Richard E. Turner

摘要:

序贯蒙特卡罗(SMC),或粒子滤波,是一种流行的方法,从一个棘手的目标分布使用一系列简单的中间分布采样。与其他基于重要性采样的方法一样,性能严重依赖于提案分布:一个糟糕的提案可能导致对目标分布的任意不准确的估计。本文提出了一种新的方法,自动适应的建议,使用近似的Kullback-Leibler分歧之间的真实后验分布和建议。该方法非常灵活,适用于任何参数化的建议分发,它支持在线和批量变量。我们使用新的框架来适应强大的建议分布与丰富的参数化的基础上神经网络导致神经自适应顺序蒙特卡罗(NASMC)。实验表明,NASMC显着改善推理的非线性状态空间模型优于自适应建议方法,包括扩展卡尔曼和无迹粒子滤波器。实验还表明,改进的推理转化为改进的参数学习时,NASMC被用作粒子边缘大都会黑斯廷斯的子程序。最后,我们表明,NASMC是能够训练的潜变量递归神经网络(LV-RNN)实现的结果,竞争与国家的最先进的多态音乐建模。NASMC可以被看作是自适应SMC方法和最近的工作在可扩展的,黑盒变分推理之间的差距。

英文摘要:

Sequential Monte Carlo (SMC), or particle filtering, is a popular class of methods for sampling from an intractable target distribution using a sequence of simpler intermediate distributions. Like other importance sampling-based methods, performance is critically dependent on the proposal distribution: a bad proposal can lead to arbitrarily inaccurate estimates of the target distribution. This paper presents a new method for automatically adapting the proposal using an approximation of the Kullback-Leibler divergence between the true posterior and the proposal distribution. The method is very flexible, applicable to any parameterized proposal distribution and it supports online and batch variants. We use the new framework to adapt powerful proposal distributions with rich parameterizations based upon neural networks leading to Neural Adaptive Sequential Monte Carlo (NASMC). Experiments indicate that NASMC significantly improves inference in a non-linear state space model outperforming adaptive proposal methods including the Extended Kalman and Unscented Particle Filters. Experiments also indicate that improved inference translates into improved parameter learning when NASMC is used as a subroutine of Particle Marginal Metropolis Hastings. Finally we show that NASMC is able to train a latent variable recurrent neural network (LV-RNN) achieving results that compete with the state-of-the-art for polymorphic music modelling. NASMC can be seen as bridging the gap between adaptive SMC methods and the recent work in scalable, black-box variational inference.

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。

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