• Title/Summary/Keyword: 웨이브렛변환

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Noise Reduction and Characteristic Points Detectoin of ECG Signal using Wavelet Transforms (웨이브렛 변환을 이용한 ECG신호의 잡음제거와 특징점 검출)

  • 장두봉;이상민;신태민;이건기
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.2 no.1
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    • pp.11-17
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    • 1998
  • One of the main techniques for diagnosing heart disease is by examining the electrocardiogram(ECG). Many studies on detecting the QRS complex, p, and T waves have been performed because meaningful information is contained in these parameters. However, the earlier detecting techniques can not effectively extract those parameters from the ECG that is severely contaminated by noise source. In this paper, we performed the extracting parameters from and recovering the ECG signal using wavelets transform that has recently been applying to various fields.

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The Recognition System of Face using Polynomial Coefficients (다항계수를 이용한 얼굴 인식 시스템)

  • 신창훈;김윤호;류광렬;이주신
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 1999.11a
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    • pp.244-247
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    • 1999
  • in this paper, we propose the recognition system of face using polynomial coefficients to recognize fact images using neural network. The system consists of following steps. First step, the sizes of fare images is reduced sizes of input images to 1/4 using wavelet transform. Second step, the polynomial coefficients is obtained from low frequency coefficient matrix after 3 level wavelet transform. Third step, polynomial coefficients is normalized. The of range of normalization is from -1 to 1. Last, Face images is trained and recognized using neural network with error back propagation algorithm.

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Two-Stage Trademark Image Retrieval using Shape Feature and Direction Feature (형태 정보와 방향 정보를 이용한 2단계 상표 영상 검색)

  • Kim, Yu-Seon;Go, Byeong-Cheol;Lee, Hae-Seong;Byeon, Hye-Ran
    • Journal of KIISE:Software and Applications
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    • v.28 no.8
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    • pp.570-581
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    • 2001
  • 본 논문에서는 윤곽선(edge) 기반의 형태 정보와 웨이브렛 변환(wavelet transform)에 의한 방향(direction) 정보를 사요하는데 2단계 상표 영상 검색 시스템을 제안한다. 1 단계에서는 후보 상표 영상을 추출하기 위해 영상의 전반적인 정보로 원 상표 영상(original trademark image)을 웨이브렛 변환하여 얻은 X, Y 방향 고주파(high frequency) 성분으로부터 구한 방향 정보와 영상의 윤곽선에 대해 모멘트를 구하는 향상된 불변 모멘트(improved invariant moment)를 이용한다. 2단계에서는 후부 영상들에 대해 영상의 세부 정보인 윤곽선 각도(edge angle)와 윤곽선 반지름(edge radius) 정보를 추출하여 유사도 측정 알고리즘을 통해 결과 영상을 산출하게 된다. 본 상표 영상 검색 시스템은 문자 색인으로는 색인이 용이 하지 않은 기하학적도형 상표 영상만을 사용하였다. 본 시스템에서는 색상과는 상관없는 특징인 형태 정보와 방향 정보만을 이용하므로 같은 색상 구성을 가진 유사 영상뿐만 아니라, 유사하지만 바탕이 반전된 영상이나 색상이 다른 유사 영상에 대해서도 바르게 검색할 수 있으며, 각 특징을 일반화해줌으로 이동.회전.크기 변화에도 불변하는 견고성을 가진다. 또한 효율적인 검색을 위해 2단계의 구조를 사용하였으며, 각 단계마다 계산량을 줄여 검색 시간을 감소시키도록 설계되었다.

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Implementation of Wavelet Transform for a Real time Monitoring ECG Telemetry System (웨이브렛 변환을 이용한 실시간 모니터링 ECG 텔레미트리 시스템 구현)

  • 박차훈;서희돈
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.1
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    • pp.27-32
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    • 2002
  • In this study, we fabricated the advanced telemetry system that transmitting media use radio frequency(RF) for the middle range measurement of the physiological signals and receiving media use optical for electromagnetic interference problem. The telemetry system within a size of 65$\times$125$\times$45mm consists of three parts: RF transmitter, optical receiver and physiological signal processing CMOS one chip. Advantages of proposed telemetry system is wireless middle range(50m) FM transmission, reduce electromagnetic interference to a minimum which enables a comfortable bed-side telemetry system. The monitoring system was designed in the structure of dual-processor for the real time processing. The use of the one channel in our study made it possible the real time wavelet transformation of electrocardiogram data of 360Hz, 16 bits for every 1.42 seconds.

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Cavitation Noise Detection Method using Continuous Wavelet Transform and DEMON Signal Processing (연속 웨이브렛 변환 및 데몬 신호처리를 이용한 캐비테이션 소음 검출 방법)

  • Lee, Hee-chang;Kim, Tae-hyeong;Sohn, Kwon;Lee, Phil-ho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.4
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    • pp.505-513
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    • 2017
  • Cavitation is a phenomenon caused by vapour cavities that is produced in rapid pressure changes. When the cavitation happened, the sound pressure level of a underwater radiated noise is increased rapidly. As a result, it can increase the probability of the identification or classification of a our warship's acoustic signature by an enemy ship. However, there is a problem that it is hard to precisely detect the occurrence of a cavitation noise. Therefore, this paper presents recent improvements in terms of the cavitation noise measurement by using continuous wavelet transform and DEMON(Detection of Envelope Modulation on Noise) signal processing. Then, we present that the suggested scheme is more suitable for detecting the cavitation than existing algorithms.

Design of Optimum Boundary Filter Bank for Sub-band Coder using M-band Orthogonal Wavelet Transform (M-대역 직교 웨이브렛 변환을 이용한 부대역 부호화기의 최적 경계필터뱅크의 설계)

  • Kwon, Sang-Keun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.8A
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    • pp.829-835
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    • 2002
  • When finite length image signal is decomposed into M-band synthesized using M-band orthogonal wavelet transform, the boundary signal of image are not reconstructed perfectly. for boundary signals to be reconstructed perfectly, different type filter bank or technique is applied to them when the dimension of analysed is proposed. It can be designed using the singular value decomposition of boundary perfect reconstruction matrix which is obtained from paraunitary matrix which is obtained from paraunitary matrix. And it is also discussed to design the boundary filter bank for improving the coding performance when it is applied to subband coder. The proposed boundary filter bank shows 7% gains in PSNR compared with reflected method.

Fast Wavelet Transform Adaptive Algorithm Using Variable Step Size (가변스텝사이즈를 적용한 고속 웨이블렛변환 적응알고리즘에 관한 연구)

  • 이채욱;오신범;정민수
    • Proceedings of the Korea Multimedia Society Conference
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    • 2004.05a
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    • pp.179-182
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    • 2004
  • 무선통신분야에서 LMS5(Least Mean Square) 알고리즘은 식이 간단하고 계산량이 비교적 적기 때문에 널리 사용되고 있다. 그러나 시간영역에서 처리할 경우 입력신호의 고유치 변동폭이 넓게 분포되어 수렴속도가 저하하는 문제점이 있다. 이를 해결하기 위하여 신호를 FFT(Fast Fourier Trasnform)나 DCT(Discrete Cosine Transform)로 변환하여 신호간의 상관도를 제거함으로써 시간영역에서 LMS알고리즘을 적용할 때 보다 수렴속도를 크게 향강시킬 수 있다. 본 논문에서는 수렴속도 향상을 위해 시간영역의 적응 알고리즘을 직교변환인 고속웨이브렛(wavelet)변환을 이용하여 변환영역에서 수행하며, 짧은 필터계수를 가지는 DWT(Discrete Wavelet Transform)특성에 맞는 Fast running FIR 알고리즘을 이용하여 WTLMS(Wavelet Transform LMS)적응알고리즘을 통신시스템에 적용한다. 적응 알고리즘의 성능향상을 위하여 시간에 따라 적응상수의 크기를 가변시켜 수렴 초기에는 큰 적응상수로 따른 수렴이 가능하도록 하고 점차 적응상수의 크기를 줄여서 misadjustment도 줄이는 방법의 적응 알고리즘을 제안하였다. 제안한 알고리즘을 실제로 적응잡음제거기(adaptive noise canceler)에 적용하여 컴퓨터 시뮬레이션을 하였으며, 각 알고리즘들의 계산량, 수렴속도를 이용하여 각각 비교, 분서하여 그 성능이 우수함을 입증하였다.

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Vehicle Detection and Classification Using Textural Similarity in Wavelet Domain (웨이브렛 영역에서의 질감 유사성을 이용한 차량검지 및 차종분류)

  • 임채환;박종선;이창섭;김남철
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.6B
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    • pp.1191-1202
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    • 1999
  • We propose an efficient vehicle detection and classification algorithm for an electronic toll collection using the feature which is robust to abrupt intensity change between consecutive frames. The local correlation coefficient between wavelet transformed input and reference images is used as such a feature, which takes advantage of textural similarity. The usefulness of the proposed feature is analyzed qualitatively by comparing the feature with the local variance of a difference image, and is verified by measuring the improvements in the separability of vehicle from shadowy or shadowless road for a real test image. Experimental results from field tests show that the proposed vehicle detection and classification algorithm performs well even under abrupt intensity change due to the characteristics of sensor and occurrence of shadow.

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A Study on the Design of Fault-Diagnosis System for Healing Mill Bearing in Wavelet Transform (웨이브렛 변환을 이용한 압연기 베어링 고장-진단 시스템 설계에 관한 연구)

  • 배영철;김이곤;최남섭;김경민;정양희
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.5
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    • pp.951-961
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    • 2000
  • A diagnosis system that provides early warnings regarding machine malfunction is very important for rolling mill so as to avoid great losses resulting from unexpected shutdown of the production line. But it is very difficult to provide early warnings in rolling mill. Because dynamics of rolling mill is non-linear. This Paper proposes a new method for diagnosis of rolling mill using wavelet transform(W) to solve this problem. Proposed method that measures the vibration signals of rolling mill on-line and analyze it using wavelet to acquire pattern data. And we design a fault-diagnosis system that diagnose a rolling mill using this data. Validity of the new method is asserted by real numerical data experiment.

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Wavelet-based Video Coding Scheme using Multi-resolution Motion Compensation (다중 해상도 움직임 보상을 이용하는 웨이브렛기반 동영상 부호화)

  • 양창모;이병기;조위덕;정하중;호용성
    • Journal of Broadcast Engineering
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    • v.7 no.1
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    • pp.37-44
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    • 2002
  • In this paper. we propose a new video coding scheme with multi-resolution motion compensation and residual quantization. The main functional blocks of the proposed scheme include multi-level wavelet decomposition. motion estimation and motion compensation. raster scanning within each subband. formation of block trees and blocking partitioning. and adaptive arithmetic coding. Although the proposed ceding scheme is simple and requires low computational complexity, it produces bitstreams tilth good features. such as the embedded structure and SNR scalability. Experimental results demonstrate that the proposed coding scheme is quote competitive to and often outperforms other wavelet-based video coding schemes in the literature.