• Title/Summary/Keyword: 김달수

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An adaptive IIR echo canceller with adaptive compensator (적응 보상기를 채용한 적응 순환 방향제거기)

  • 최삼길;김달수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.4
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    • pp.876-883
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    • 1996
  • Adaptive FIR filters are widely used in the echo canceller. But, most of practical systems have the transfer function composed of poles and zeros. In that case, adaptive IIR filters may be more efficient rather than FIR fiters. In this paper, a recently developed C-HARF algorithm is used to implement an adaptive IIR echo canceller. The proposed convergence of the algorithm make it attractive for this application. Extensive computer simulations show that C-HARF algorithm performs better than the NLMS algorithm after convergence, although C-HARF algorithm converges more slowly.

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Constrained Multichannel Adaptive FIR Beamforming Algorithm Based upon Least Squares Method (최소자승법을 이용한 Constrained Multichannel FIR 적응 빔 형성 알고리즘)

  • 김달수;신윤기;박의열
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.28A no.9
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    • pp.671-679
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    • 1991
  • In adaptive antenna, several models are known according to a prior knowledge about jammer signal. Among those, Frost model with contraint is generally used however it has the problem that convergence speed is slow and that stability is not good. To improve such problems, this paper proposes constrained NLMS algorithm using LS method. In addition, the result obtained by applying this algorithm to Duvall antenna model is compared with that of Frost model.

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Surgical Complication and Its Management in Ischemic Stroke (허혈성뇌졸중의 수술치료시 동반되는 합병증과 관리)

  • Kim, Dal Soo;Yoo, Do Sung;Huh, Pil Woo;Cho, Kyoung Suok;Kang, Joon Ki
    • Journal of Korean Neurosurgical Society
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    • v.29 no.8
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    • pp.1107-1112
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    • 2000
  • Recently various operative procedures including microsurgery or endovascular surgery have been increasing for the management of ischemic cerebrovascular diseases. Carotid endarterectomy(CEA), extracranial-intracranial(EC-IC) arterial bypass, embolectomy, decompressive craniectomy, arterial transposition, intravascular thrombolysis, and percutaneous transarterial angioplasty and stenting (PTAS) are available surgical modalities for ischemic stroke. This article focuses the complications and perioperative management of patients treated with CEA and carotid PTAS among various surgical managements for ischemic stroke.

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Multichannel Adaptive IIR Beamforming Algorithm of Output Error Method (출력오차방법의 다채널 IIR 적응 빔 형성 알고리즘)

  • 김달수;박의열
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.4
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    • pp.530-536
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    • 1993
  • In adaptive antenna, recently Gooch suggested a new adaptive system using equation error method, but the system demands inverse model about the pole part and thus does not guarantee stability. In this paper, algorithm is proposed that has a basis on Popov's extra-stability theory. And system is developed of output error method. In addition, the result obtained by applying proposed algorithm to system of output error method is compared with that of Gooch model.

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Study of a New LOCOS Process Using Only Thin LPCVD Nitride (LPCVD 질화막 만을 이용한 새로운 LOCOS 공정에 관한 연구)

  • Kim, Ji-Bum;Oh, Ki-Young;Kim, Dal-Soo;Joo, Seung-Ki;Choi, Min-Sung
    • Proceedings of the KIEE Conference
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    • 1987.07a
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    • pp.429-432
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    • 1987
  • A new LOCOS (Local Oxidation of Silicon) process using a thin nitride film directly deposited on the silicon substrate by LPCVD has been developed in order to reduce the bird's beak length. SEM studies showed that nitride thickness of 50nm can decrease the bird's beak length down to 0.2um with 450nm field oxide. No crystalline defects are observed around the bird's beak after the Wright etch. A 30% improvement in current density was obtained when this new method was applied to MOS transistors (W/L*2.9/20.4) compared to conventional LOCOS process (bird's beak length=0.7um). Other various electrical parameters improved by this new simple LOCOS process are reported in this paper.

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