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A discrete-time control problem of a finite-state hidden Markov chain partially observed in a fractional Gaussian process is discussed using filtering. The control problem is then recast as a separated problem with information variables given by the unnormalized conditional probabilities of the whole path of the hidden Markov chain. A dynamic programming result and a minimum principle are obtained. 相似文献
54.
A hidden Markov model (HMM) with a special structure that captures the ‘semi’-property of hidden semi-Markov models (HSMMs) is considered. The proposed model allows arbitrary dwell-time distributions in the states of the Markov chain. For dwell-time distributions with finite support the HMM formulation is exact while for those that have infinite support, e.g. the Poisson, the distribution can be approximated with arbitrary accuracy. A benefit of using the HMM formulation is that it is easy to incorporate covariates, trend and seasonal variation particularly in the hidden component of the model. In addition, the formulae and methods for forecasting, state prediction, decoding and model checking that exist for ordinary HMMs are applicable to the proposed class of models. An HMM with explicitly modeled dwell-time distributions involving seasonality is used to model daily rainfall occurrence for sites in Bulgaria. 相似文献
55.
侯传宇 《数字社区&智能家居》2008,(3):1186-1189
随着用户对于数据挖掘的精确度与准确度要求的日益提高,马尔可夫模型与隐马尔可夫模型被广泛用于数据挖掘领域。本文阐述了马尔可夫模型和隐马尔可夫模型数据挖掘领域的应用,以及隐马尔可夫模型可解决的问题,以供其他研究者借鉴。 相似文献
56.
HE Jun 《数字社区&智能家居》2008,(21)
MAC协议是无线自组织网络中一个重要研究领域,特别是隐终端和暴露终端问题的解决尤为重要。目前已经提出了一些MAC协议的设计方案,但这些方案都是孤立存在的,为了能从整体上了解MAC协议发展现状,对现有的MAC协议进行了归类并且对它们进行了简单分析比较,作为结论,给出了MAC协议的发展方向。 相似文献
57.
A model-based hand gesture recognition system 总被引:2,自引:0,他引:2
This paper introduces a model-based hand gesture recognition system, which consists of three phases: feature extraction,
training, and recognition. In the feature extraction phase, a hybrid technique combines the spatial (edge) and the temporal
(motion) information of each frame to extract the feature images. Then, in the training phase, we use the principal component
analysis (PCA) to characterize spatial shape variations and the hidden Markov models (HMM) to describe the temporal shape
variations. A modified Hausdorff distance measurement is also applied to measure the similarity between the feature images
and the pre-stored PCA models. The similarity measures are referred to as the possible observations for each frame. Finally,
in recognition phase, with the pre-trained PCA models and HMM, we can generate the observation patterns from the input sequences,
and then apply the Viterbi algorithm to identify the gesture. In the experiments, we prove that our method can recognize 18
different continuous gestures effectively.
Received: 19 May 1999 / Accepted: 4 September 2000 相似文献
58.
This paper illustrates two strategies for the detection and classification of abnormal process operating conditions in which multiple process variable trends are available. The first strategy uses a hidden Markov model (HMM) for overall process classification while the second method uses a back-propagation neural network (BPNN) to determine the overall process classification. The methods are compared in terms of their ability to detect and correctly diagnose a variety of abnormal operating conditions for a non-isothermal CSTR simulation. For the case study problem, the BPNN method resulted in better classification accuracy with a moderate increase in training time compared with the HMM approach. 相似文献
59.
改进的选择神经网络结构的方法 总被引:3,自引:1,他引:2
有关人工神经网络作为在线状态估计器组成基于神经网络的传感器故障检测的研究已有报导。但是这些文章中没有提到如何选择神经网络的结构。神经网络的输入延迟数和隐基单元数影响其对系统的拟合精度,从而影响故障检测的灵敏度。研究了一些现有的选择神经网络结构的方法,以系统化的交叉证实法为基础,经过改进,提出了针对作为在线状态估计器的神经网络选择输入延迟数和隐层单元数的系统化的方法,并用某船在试验场中航行时平台罗经输出的一段数据作了仿真,结果证明该法可行,具有工程实用意义。 相似文献
60.
The arguments given in this paper suggest that Grover’s and Shor’s algorithms are more closely related than one might at first
expect. Specifically, we show that Grover’s algorithm can be viewed as a quantum algorithm which solves a non-abelian hidden
subgroup problem (HSP). But we then go on to show that the standard non-abelian quantum hidden subgroup (QHS) algorithm can
not find a solution to this particular HSP. This leaves open the question as to whether or not there is some modification
of the standard non-abelian QHS algorithm which is equivalent to Grover’s algorithm.
相似文献