• Title/Summary/Keyword: Blocking signal

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Acoustic Signal Processing & Analysis for Blocking Internet Harmful Phonographic Sites (음란 유해사이트 차단을 위한 음향 신호 처리 및 분석)

  • 조동욱;김지영
    • The Journal of the Korea Contents Association
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    • v.4 no.2
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    • pp.1-6
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    • 2004
  • This paper proposes on the acoustic signal processing blocking method of Internet pornographicl sites by calculating correlation values between prototype acoustic signals and input acoustic signals. Pre-existing blocking methods mainly focused on directory-based bled(fin and pornographic related words-based blocking. But these methods are not completely blocked the Internet harmful pornographicl sites by several situations. For this, this paper proposes the content-based blocking method which composes of the image-based blocking and the acoustic-based blocking. This paper, mainly, deals with the acoustic -based blocking method. Finally, the effectiveness of this system is demonstrated by several experiments.

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Blocking of Internet Harmful Sex Sites by Accoustic Signal Processing (음향 신호 처리에 의한 음란 유해 사이트의 차단)

  • 이범주;김도연;장민형;박은배;신관철;유정선;조동욱;문창배
    • Proceedings of the Korea Contents Association Conference
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    • 2003.11a
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    • pp.481-485
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    • 2003
  • This paper proposes on the blocking method of Internet harmful sex sites by accoustic signal processing. Pre-existing methods mainly focused on directory-based blocking and words-based blocking. But these methods are not completely blocked the Internet harmful sites. Therefore, we propose the content-based blocking method which compose of the image-based blocking and the accoustic-based blocking. In this paper, we mainly deal with the accoustic -based blocking method. Finally, the effectiveness of this system is demonstrated by several experiments.

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Improved Leakage Signal Blocking Methods for Two Channel Generalized Sidelobe Canceller

  • Kim, Ki-Hyeon;Ko, Han-Seok
    • Speech Sciences
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    • v.13 no.1
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    • pp.117-128
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    • 2006
  • The two-channel Generalized Sidelobe Canceller (GSC) scheme suffers from the presence of leakage signal in the reference channel. The leakage signal is caused by the dissimilar impulse responses between microphones, and different paths from speech source to microphones. Such leakage is detrimental to speech enhancement of the GSC since the desired reference signal becomes corrupted. In order to suppress the signal leakage, two matrix injection methods are proposed. In the first method, a simple gain compensation matrix is used. In the second, a projection matrix for reducing the error between the actual and the ideal primary and reference signals, is used. This paper describes the performance degradation resulting from leakage, and proposes effective methods to resolve the problem. Representative experiments were conducted to demonstrate the effectiveness of the proposed methods on recorded speech and noise in an actual automobile environment.

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A Study on the Design of a Digital Hearing Aids Signal Processing System in the Wavelet Transform Domain (WT평면에서의 디지탈 청각 보조 신호 처리 시스템의 설계)

  • 이현철;석광원
    • Journal of Biomedical Engineering Research
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    • v.17 no.3
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    • pp.347-354
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    • 1996
  • This paper presents digital hearing aids signal processing system in WT(wavelet transform) domain. For implementation of hearing aids in WT domain, the gain in frequency domain is approximated in WT domain. We also present the gain selection algorithm to deal with the change of input signal power. Most transform methods produce blocking effect, and this effect degrades the convergence rate of feedback canceller. As a solution, we proposed wavelet transform bascd feedback canceller. To evaluate the performance, we compared it with LOT (lapped orthogonal transform) method in the frequency domain. This system has not shown the blocking effect, and improves convergence rate as compared with the LOT based feedback canceller.

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A Study on the Design and Implement of The Function of the Sidelobe Blanking of VHF Radar (초단파 레이다의 부엽 차단 기능에 대한 설계 및 구현에 대한 연구)

  • Kim, Ki-Jung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.4
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    • pp.637-642
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    • 2020
  • In this study, the SLB(Sidelobe Blanking)/BLB(Blacklobe Blanking) design of the VHF band radar using the low-frequency band having a relatively larger beam width than the S-band or X-band radar. The antenna of the VHF band has a relatively large beam width, so it is reflected from the side lobe. If the reflected target signal is not processed into sidelobe, the false alarm rate of the radar increases by recognizing it from the main lobe signal. This method of SLB blocking is the elimination of the side lobe signal in the front of the array antenna using the central radiating element of the array antenna, and the blocking of side lobe signal from the antenna rear through BLB receiver block. After completed the radar implementation, The function of blocking of side lobe signals was confirmed through the system unit test by Simulated signal generator. Through this study, it will be used in the implementation of the side-lobe blocking technology of the array antenna for low-frequency band radar with large antenna size and beam width in the future.

어류 rhabdovirus의 신속 진단을 위한 Oligonucleotide chip의 개발 2. Oligonucleotide chip을 위한 기반 조건 구축

  • 김영주;강지희;임재성;김상봉;이명숙
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2003.05a
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    • pp.311-312
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    • 2003
  • Microarray를 해석하는데 있어서 방해가 되는 요인에는 여러 가지가 있을 수 있다. 예를 들면 probe DNA의 농도, spotting 시의 습도, spot의 크기 및 모양, slide blocking 과정, lab리ing technique, hybri야zation 온도와 시간 그리고 background signal 등이 그것이다(Hegde et at., 2000). 본 연구에서는 전보에서 선정된 rhabdovirus의 96개 probe로 실제 oligonucleotide chip을 만들어 spot의 모양이나 크기에 관계되는 spotting 조건을 확립하고, slide blocking과 slide washing에 따른 background signal을 낮추기 위한 과정을 도입하였다. (중략)

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Performance on Channel Multiple Access for the OBP Satellite (OBP(On-Board Processing)위성의 채널 다중 접속 방식에 대한 성능 연구)

  • 이정렬;김덕년
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2000.12a
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    • pp.5-8
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    • 2000
  • In this paper, The new scheme for Demand Assigned Multiple Access(DAMA) system is proposed. To focus on the onboard processor's specific monitoring of output port of the downlink, we found the Throughput and Blocking probability by the request traffic(λ) and channel's departure probability(Ρ).

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Blocking Artifacts Detection in Frequency Domain for Frame Rate Up-conversion (프레임율 변환을 위한 주파수 영역에서의 블로킹 현상 검출)

  • Kim, Nam-Uk;Jun, Dongsan;Lee, Jinho;Lee, Yung-Lyul
    • Journal of Broadcast Engineering
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    • v.21 no.4
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    • pp.472-483
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    • 2016
  • This paper proposes a blocking artifacts detection algorithm in frequency domain for MC-FRUC (Motion Compensated Frame Rate Up-Conversion). Conventional MC-FRUC algorithms occur blocking artifacts near interpolated block boundaries since motion compensation is performed from block-based motion vector. For efficiently decreasing blocking artifacts, this paper analyses frequency characteristics of the interpolated frame and reduces blocking artifacts on block boundaries. In experimental results the proposed method shows better subjective quality than some conventional FRUC method and also increases the PSNR(Peak Signal to Noise Ratio) value on average 0.45 dB compared with BDMC(Bi-Directional Motion Compensation).

Ghost and Blocking of TV signal by UHV Transmission Lines (대형 송전선로에 의한 TV 전파장해 고찰)

  • Shin, Koo-Yong;Lee, Dong-Il
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1776-1778
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    • 1998
  • KEPCO has been constructing the 765 kV double circuit transmission line since 1997. It is worried that the 765 kV transmission lines make TV interference(Ghost and Blocking) due to high tower and multi sub-conductors. This paper presents the mechanism, the measuring method and the results of TV ghost and blocking measurement using a new TV ghost measurement system in a vehicle which was developed by KEPRI.

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Signal-Blocking-Based Robust Adaptive Beamforming by Interference Null Space Projection (간섭 널 공간 투사에 의한 신호차단 방식의 적응 빔 형성)

  • Choi, Yang-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.4A
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    • pp.399-406
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    • 2011
  • Adaptive beamformers, which utilize a priori information on the arrival angle of the desired signal. suppress interferences while maximizing their gains in the desired signal direction. However, if there exist errors in the direction information, they can suffer from severe performance degradation since the desired signal is treated as an interference. A robust adaptive beamforming method is presented which exploits the signal-blocking structure of the Duvall beamformer. The proposed method finds an interference signal space directly from correlations of received signals and then obtains a weight vector such that it is orthogonal to the space. Applying the weight vector to two sub arrays which consist of one less sensors than the original uniform lineal array (ULA), the beamformer efficiently estimates the arrival angle of the desired signal. Its computational complexity is lower than existing methods, which require matrix inversion or eigendecomposition.