• Title/Summary/Keyword: Matched filter

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Facial Image Detection with Matched Filters (Matched Filter를 이용한 얼굴 영상 검출)

  • 황인택;신명숙;최광남
    • Proceedings of the Korea Multimedia Society Conference
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    • 2003.11a
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    • pp.208-211
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    • 2003
  • 이 논문은 Matched Filter 기술을 사용해 다양한 영상 중 얼굴 영상을 분류하는 연구에 대해서 기술한다. 기본 목표는 얼굴 영상과 그 외의 영상을 분류할 수 있는 효과적인 필터를 개발하는 것이다. 이런 Matched Filter는 Fourier 역변환을 사용해 훈련영상(Training Image)으로부터 얻을 수 있다. 실험평가는 Yale대학의 얼굴 데이터베이스의 얼굴영상과 다양한 형태를 보이는 임의의 영상으로 평가한다. 우리는 여기서 얼굴 영상을 분류하기 위한 방법 중 한가지로서 Matched Filter를 이용할 수 있음을 확인할 수 있다.

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Accuracy of Free Space Path Loss and Matched Filter Gain Approximated by Using Passband Rectangular Pulse for Ultra Wideband Radio Systems

  • Supanakoon, Pichaya;Tanchotikul, Suchada;Tangtisanon, Prakit;Promwong, Sathaporn;Takada, Jun-Ichi
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.223-226
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    • 2004
  • This paper analyzes the accuracy of free space path loss and matched filter gain approximated by using a passband rectangular pulse for ultra wideband (UWB) radio systems. The example causal signal, a modulated Gaussian pulse with the same center frequency and frequency bandwidth of the passband rectangular pulse, is used to consider the accuracy. The path loss and matched filter gain of the modulated Gaussian pulse are simulated for the reference results. The UWB free space path loss is shown and is compared with that obtained from simulation and Friis' transmission formula. The UWB matched filter gain is shown and compared with simulation results. From the results, we can see that the UWB path loss formula is more accurate than the Friis' transmission formula. The results from the UWB free space path loss and matched filter gain formulas agree with the simulation. Then, these free space path loss and matched filter gain formulas approximated by using a passband rectangular pulse are appropriate for UWB system.

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Adaptive Filtering for QRS Detection (QRS검출을 위한 Adaptive Filter)

  • Lee, Soon-Hyouk;Jun, Young-Il;Choi, Kyoung-Hoon;Yoon, Hyung-Ro
    • Proceedings of the KOSOMBE Conference
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    • v.1993 no.11
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    • pp.167-170
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    • 1993
  • matched filter는 신호와 잡음의 통계적 값을 알고 있을 때 신호대 잡음비를 최대로 하는 filter이다. 그런데, matched filter가 최적화 되려면 잡음이 white noise이어야한다. 그러나 ECG신호에 존재하는 잡음은 여러가지 성분이 공존하는 서로 연관되어있는 잡음이다. 따라서 whitening filter를 사용하여 잡음을 whitening시킨후에 matched filter를 통과 시켜야한다. 본 논문에서는 QRS complex를 검출하기 위한 matched filter에 있어서 LMS방법을 이용한 linear whitening filter와 neural network을 이용한 non-linear whitening filter의 특성을 비교하였다.

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Estimating Facial Feature Position with Matched Filters (Matched Filter를 이용한 얼굴 특징점 위치추출)

  • 황인택;최광남
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.10b
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    • pp.565-567
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    • 2003
  • 이 논문은 Matched Filter 기술을 사용해 얼굴 특징점 위치를 추출하는 연구에 대해서 기술한다. 기본 목표는 얼굴의 서로 다른 8개( 양쪽 눈과 눈썹, 머리선, 코, 입, 턱 )의 부분을 구분할 수 있는 필터들을 개발하는 것이다. 이런 Matched Filter는 Fourier 역변환을 사용해 훈련영상(Training Image)으로부터 얻을 수 있다. 실험평가는 베른대학의 얼굴 데이터베이스에 근거한다. 우리는 여기서 다양한 얼굴의 방향성에 효과적으로 적용할 수 있도록 하는 훈련 영상자료가 무엇인지 알 수 있다. 그리고 안경을 썼을 때 얼굴을 인식할 수 있는 가장 좋은 방법도 알아본다.

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A Design of Low Power Digital Matched Filter using Rounding for IMT-2000 Communication Systems (IMT-2000 통신시스템에서의 라운딩을 이용한 저전력 디지털 정합필터의 설계)

  • Park, Ki-Hyun;Ha, Jin-Suk;Nam, Ki-Hun;Cha, Jae-Sang;Lee, Kwang-Youb
    • Journal of IKEEE
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    • v.8 no.1 s.14
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    • pp.145-151
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    • 2004
  • For wide-band spread spectrum communication systems such as IMT-2000, a digital matched filter is a key device for rapid spreading code synchronization. Although a digital matched filter can be implemented easily, large power consumption at the higher chip rate and large summation delay of longer chip length are the bottleneck of practical use. In this paper, we propose a optimized partial correlation digital matched filter structure which can be constructed of the so-called generalized hierarchical Golay sequence. a partial correlation structure can reduce the number of correlators, but enlarge the size of flip-flops. In this paper, The proposed approach focuses on efficient circuit size, power dissipation, maintaining the operating throughput. A proposed digital matched filter reduce the size of flip-flops by rounding method. and it reduces about 45 percentages of power dissipation and chip area as compared with digital matched filter which is not rounded. rounding. The proposed architecture was verified by using Xilinx FPGA.

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A Matched Filter with Two Data Flow Paths for Searching Sychronization in DSSS (DSSS 동기탐색을 위한 이중 데이터 흐름 경로를 갖는 정합필터)

  • Song Myong-Lyol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.1A
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    • pp.99-106
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    • 2004
  • In this Paper, the matched filter for searching initial synchronization in DSSS (direct sequence spread spectrum) receiver is studied. The matched filter with a single data flow path is described which can be presented by HDL (Hardware Description Language). In order to improve the processing time of operations for the filter, equations are arranged to represent two data flow paths and the associated hardware model is proposed. The model has an architecture based on parallelism and pipeline for fast processing, in which two data flow paths with a series of memory, multiplier and accumulator are placed in parallel. The performance of the model is analyzed and compared with the matched filter with a single data flow path.

A Study on the Wavelet Matched Filter Design and Correlation Properties in the Optical Correlator (웨이브릿 정합 필터의 설계와 광상관기 구조에서의 상관특성에 관한 연구)

  • 김주영;김석희
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.4
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    • pp.701-711
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    • 1994
  • In this paper, we design wavelet matched filters using Wavelet Transform available in the field of time-frequency analysis, for the optical patter recognition, and study optical correlation properites according to variations of the dilation factor of wavelet functions, which were compared with conventional matched filter and POF. We have found that the wavelet matched filters depend upon the shapes if used input patterns and dilation factors of the wavelet function in order to have the best dicriminability. Also, we show the edge enhanced effects of 2-D image, which is one of the properities of the wavelet transform. If has been found that the wavelet matched filter can discriminate better than the conventional matched filter and POF owing to their bandpass properties, and found that the proposed wavelet matched filters have more sensitive correlation response than POF.

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A Performance Analysis of Burst-format Serial Search DS-SS Acquisition System Using Digital Matched Filter (디지털 정합 필터를 이용한 버스트 형 직렬 탐색 DS-SS초기 동기 시스템의 성능 분석)

  • 이동욱;홍인기;황금찬
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.8
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    • pp.701-709
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    • 1991
  • In this paper, an analysis approach for the performance of serial search burst format direct sequence spread spectrum[DS-SS] code aequision system using matched filter is persented. And an acquisition system using digital matched filter is chosen for the analysis by this approach. In this acqusition system, since chip decision should be performaned before matched filter

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A Novel GPS Initial Synchronization Scheme with Decomposed Differential Matched Filter (분해형 차분 정합필터를 갖는 새로운 GPS 초기동기 방식)

  • Park, Sang-Hyun;Lee, Sang-Jeong
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.2
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    • pp.185-192
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    • 2002
  • A novel GPS initial synchronization scheme with low hardware complexity is proposed. The proposed method has the decomposed differential matched filter, which consists of 25% multiplier and adder of the conventional matched filter. This paper presents the generalized mean acquisition time of initial synchronization scheme with multiple correlator. It is shown that the proposed method, in spite of its low hardware complexity, has the equal performance to the conventional method. The performance of the proposed method is verified through the simulation test by the GPS simulator. It is shown that the proposed method prevents the squaring loss of non-coherent integration.

A Fuzzy Logic Based Bin-Picking Technique (퍼지노리를 이용한 Bin-Picking방법)

  • 김태원;서일홍
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.41 no.8
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    • pp.938-946
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    • 1992
  • A novel 2-dimensional matched filter of the parallel-jaw type using fuzzy logic is proposed for bin picking. Specifically, the averaged pixel intensity of the windowed region for the filtering is considered to be fuzzy. Also membership functions for darkness and brightness are designed by employing the intensity histogram of the image. Then a rule is given to know how much a windowed region can be a possible holdsite. Furthermore eight rules are made to determine the part orientation, where Mamdani's reasoning method is applied. The proposed technique shows better performances than that of the conventional matched filtering technique in the following senses` 1) most of holdsites determined by the proposed technique are not concentrated at the locations nearly the end of part and 2) our filter is rather insensitive to noises than the conventional method. To show the validities of our proposed technique, some experimental results are illustrated and compared with the results by conventional matched filter technique.

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