• Title/Summary/Keyword: HMM(HMM)

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Frontal view face recognition using the hidden markov model and neural networks (은닉 마르코프 모델과 신경회로망을 이용한 정면 얼굴인식)

  • 윤강식;함영국;박래홍
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.9
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    • pp.97-106
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    • 1996
  • In this paper, we propose a face recognition algorithm using the hidden markov model and neural networks (HMM-NN). In the preprocessing stage, we find edges of a face using the locally adaptive threshold (LAT) scheme and extract features based on generic knowledge of a face, then construct a database with extracted features. In the training stage, we generate HMM parameters for each person by using the forward-backward algorithm. In the recognition stage, we apply probability vlaues calculated by the HMM to subsequent neural networks (NN) as input data. Computer simulation shows that the proposed HMM-NN algorithm gives higher recognition rate compared with conventional face recognition algorithms.

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Variational Bayesian Methods for Learning HMM with Mixture of Gaussian Outputs (가우시안 혼합 출력 HMM을 위한 변분 베이지안 방법)

  • O Jangmin;Zhang Byoung-Tak
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.07b
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    • pp.619-621
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    • 2005
  • 은닉 마코프 모델은 이산 동역학을 표현할 수 있는 확률 모형이다. 우도 함수 최적화를 수행하는 전통적인 Baum-Welch 학습 알고리즘은 국소해로 수령하기 쉬우며, 우도함수의 특성상 복잡한 모델을 선호하는 바이어스가 존재한다. 베이지안 프레임워크에서는 파라미터를 랜덤 변수로 보고 이에 대한 사후 확률 분포를 추정하여 이 문제를 해결할 수 있다. 본 논문에서는 베이지안 추정을 위한 결정론적 근사화 기법인 변분 베이지안 방법을 이용, 출력 노드에 가우시안 혼합 노드를 지니는 일반화된 HMM의 추론 방법을 유도한다. 인공 데이터에 대한 실험을 통해, 본 방법이 효과적인 HMM 학습을 수행할 수 있음을 보인다.

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A Study on the Synthesis of HMM and GA-MLP for EMG Signal Recognition (근전도 신호인식을 위한 HMM과 GA-MLP의 합성에 관한 연구)

  • Shin, C.K.;Lee, D.H.;Lee, S.M.;Kwon, J.W.;Hong, S.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.11
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    • pp.199-202
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    • 1996
  • In this paper, we suggested the combination of HMM(Hidden Markov Model) and MLP (Multi-Layer Perceptron) with GA(genetic algorithm) for a recognition of EMG signals. To describe EMG signal's dynamic properties, HMM algorithm was adapted and due to its outstanding abilities in static signal classification MLP was connected as a real processor. We also used GA( Genetic Algorithm) for improving MLP's learning rate. Experimental results showed that the suggested classifier gave higher EMG signal recognition rates with faster learning time than other one.

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Named Entity Boundary Recognition Using Hidden Markov Model and Hierarchical Information (은닉 마르코프 모델과 계층 정보를 이용한 개체명 경계 인식)

  • Lim, Heui-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.2
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    • pp.182-187
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    • 2006
  • This paper proposes a method for boundary recognition of named entity using hidden markov model and ontology information of biological named entity. We uses smoothing method using 31 feature information of word and hierarchical information to alleviate sparse data problem in HMM. The GENIA corpus version 2.1 was used to train and to experiment the proposed boundary recognition system. The experimental results show that the proposed system outperform the previous system which did not use ontology information of hierarchical information and smoothing technique. Also the system shows improvement of execution time of boundary recognition.

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Unsupervised Speaker Adaptation Based on Sufficient HMM Statistics (SUFFICIENT HMM 통계치에 기반한 UNSUPERVISED 화자 적응)

  • Ko Bong-Ok;Kim Chong-Kyo
    • Proceedings of the KSPS conference
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    • 2003.05a
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    • pp.127-130
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    • 2003
  • This paper describes an efficient method for unsupervised speaker adaptation. This method is based on selecting a subset of speakers who are acoustically close to a test speaker, and calculating adapted model parameters according to the previously stored sufficient HMM statistics of the selected speakers' data. In this method, only a few unsupervised test speaker's data are required for the adaptation. Also, by using the sufficient HMM statistics of the selected speakers' data, a quick adaptation can be done. Compared with a pre-clustering method, the proposed method can obtain a more optimal speaker cluster because the clustering result is determined according to test speaker's data on-line. Experiment results show that the proposed method attains better improvement than MLLR from the speaker independent model. Moreover the proposed method utilizes only one unsupervised sentence utterance, while MLLR usually utilizes more than ten supervised sentence utterances.

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A Gesture-based Game Interface using HMM (HMM을 이용한 제스처 기반의 게임 인터페이스)

  • 장상수;박혜선;김상호;김항준
    • Proceedings of the Korean Information Science Society Conference
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    • 2004.04b
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    • pp.496-498
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    • 2004
  • 본 논문에서는 컴퓨터 액션 게임 중에 하나인, 퀘이크 II 게임을 위한 제스처 기반의 인터페이스를 제안한다. 제안된 인터페이스는 연속된 입력 영상열로부터 재스처를 검출하고 인식하기 위해 HMM 올 사용한다. 먼저 재스처를 검출하기 위해 입력 영상열로부터 포즈 심볼열을 추출하여 사용한다. 인식하기 위해 사용된 HMM은 추출된 포즈 심볼을 입력받아, 상태 확률값을 계산하여 계속적으로 갱신한다 이때 갱신되는 상태 확률값 중에 각 제스처에 속하는 특정상태의 확률값이, 미리 정의된 임계간과 비교하여 초과하면 검출되고 인식된다. 현재 제안된 시스템은 실제 퀘이크 II 게임에서 키보드버튼과 마우스를 통해 입력되는 명령어들 중에서 게임을 진행하기 위해 먼저 필요한 움지임과 시점 변환에 관계되는 명령어들을 13 개의 제스처로 표현하고 이 제스처 명령어를 검출하고 인식한다.

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A Semi-supervised Learning of HMM to Build a POS Tagger for a Low Resourced Language

  • Pattnaik, Sagarika;Nayak, Ajit Kumar;Patnaik, Srikanta
    • Journal of information and communication convergence engineering
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    • v.18 no.4
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    • pp.207-215
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    • 2020
  • Part of speech (POS) tagging is an indispensable part of major NLP models. Its progress can be perceived on number of languages around the globe especially with respect to European languages. But considering Indian Languages, it has not got a major breakthrough due lack of supporting tools and resources. Particularly for Odia language it has not marked its dominancy yet. With a motive to make the language Odia fit into different NLP operations, this paper makes an attempt to develop a POS tagger for the said language on a HMM (Hidden Markov Model) platform. The tagger judiciously considers bigram HMM with dynamic Viterbi algorithm to give an output annotated text with maximum accuracy. The model is experimented on a corpus belonging to tourism domain accounting to a size of approximately 0.2 million tokens. With the proportion of training and testing as 3:1, the proposed model exhibits satisfactory result irrespective of limited training size.

Hydrogen Peroxide Promotes Epithelial to Mesenchymal Transition and Stemness in Human Malignant Mesothelioma Cells

  • Kim, Myung-Chul;Cui, Feng-Ji;Kim, Yongbaek
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.6
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    • pp.3625-3630
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    • 2013
  • Reactive oxygen species (ROS) are known to promote mesothelial carcinogenesis that is closely associated with asbestos fibers and inflammation. Epithelial to mesenchymal cell transition (EMT) is an important process involved in the progression of tumors, providing cancer cells with aggressiveness. The present study was performed to determine if EMT is induced by $H_2O_2$ in human malignant mesothelioma (HMM) cells. Cultured HMM cells were treated with $H_2O_2$, followed by measuring expression levels of EMT-related genes and proteins. Immunohistochemically, TWIST1 expression was confined to sarcomatous cells in HMM tissues, but not in epithelioid cells. Treatment of HMM cells with $H_2O_2$ promoted EMT, as indicated by increased expression levels of vimentin, SLUG and TWIST1, and decreased E-cadherin expression. Expression of stemness genes such as OCT4, SOX2 and NANOG was also significantly increased by treatment of HMM cells with $H_2O_2$. Alteration of these genes was mediated via activation of hypoxia inducible factor 1 alpha (HIF-$1{\alpha}$) and transforming growth factor beta 1 (TGF-${\beta}1$). Considering that treatment with $H_2O_2$ results in excess ROS, the present study suggests that oxidative stress may play a critical role in HMM carcinogenesis by promoting EMT processes and enhancing the expression of stemness genes.