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语法推理作为主成分分析问题

Grammatical Inference as a Principal Component Analysis Problem
课程网址: https://videolectures.net/videos/icml09_bailly_gipcap  
主讲教师: Raphaël Bailly
开课单位: 会议
开课时间: 2009-08-26
课程语种: 英语
中文简介:
概率语法推理的主要问题之一在于从根据固定的未知目标分布p独立绘制的单词样本中推断出随机语言,即某类概率模型中的概率分布。在这里,我们考虑由随机语言组成的有理随机语言类,这些随机语言可以通过多元自动机计算,这可以被视为概率自动机的推广。有理随机语言p具有一个有用的代数特征:所有映射up:v-p(uv)都位于向量空间R(E)的一个有限维向量子空间Vp中,该向量空间由E上定义的所有实值函数组成。因此,语法推理过程的第一步可以是识别子空间Vp。本文研究了使用主成分分析来实现这一任务的可能性。我们提供了一种推理算法,用于计算目标分布的估计值。我们证明了该算法的一些理论性质,并提供了数值模拟的结果,证实了我们方法的相关性。
课程简介: One of the main problems in probabilistic grammatical inference consists in inferring a stochastic language, i.e. a probability distribu- tion, in some class of probabilistic models, from a sample of words independently drawn according to a fixed unknown target distribution p. Here we consider the class of rational stochastic languages composed of stochastic languages that can be computed by muliplicity automata, which can be viewed as a generalization of probabilistic automata. Rational stochastic languages p have a useful algebraic characterization: all the mappings up:v-¿p(uv) lie in a finite dimensional vector subspace Vp of the vector space R(E) composed of all real-valued functions defined over E. Hence, a first step in the grammatial inference process can consist in identifying the subspace Vp. In this paper, we study the possibility of using principal component analysis to achieve this task. We provide an inference algorithm which computes an estimate of the target distribution. We prove sometheoreticalpropertiesofthisalgorithmandweprovideresultsfromnumericalsimulationsthatconfirm the relevance of our approach.
关 键 词: 语法推理; 主成分; 分析问题
课程来源: 视频讲座网
数据采集: 2025-04-25:liyq
最后编审: 2025-04-25:liyq
阅读次数: 8