• Title/Summary/Keyword: 역확산

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농업기술 - 구제역과 AI, 겨울철 주의해야 할 가축질병 관리기술

  • Jeong, Yeong-Hun
    • 농업기술회보
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    • v.51 no.6
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    • pp.14-15
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    • 2014
  • 구제역과 조류인플루엔자 등 악성전염병의 발생 후 방역조치는 매우 힘들고 어려우며 국가적으로 많은 손실을 유발하기 때문에 각 농장마다 차단방역 조치를 철저히 실시해 질병의 발생 및 확산을 막아야 한다. 겨울철 주의해야 할 가축질병의 관리기술에 대해 알아보자.

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Diffusion Analysis for Optimal Design of Ocean Outfall System (해양방류시스템 최적설계를 위한 확산해석)

  • Jung, T.S.;Kang, S.W.
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.12 no.3
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    • pp.124-132
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    • 2009
  • The optimal type and discharging position of ocean outfall of wastewater have been determined by hydrodynamic modeling, near-field dilution modeling, and far-field dispersion modeling. Tide and tidal currents have been simulated by a finite element hydrodynamic model showing good agreements with field observations. Based on the hydrodynamic simulation results candidates of ocean outfall position were preliminary determined. Submerged single port and submerged multi-port diffuser were selected as discharging system alternatives and finally designed by considering tide, tidal currents and water depth. Initial dilution of wastewater discharged from the designed ports has been estimated by CORMIX system. A 2-dimensional random-walk dispersion model has been employed to simulate far-field dispersion of discharged wastewater.

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Inverse halftoning algorithm using local binary pattern based lookup table (국부 이진패턴 기반 참조표를 이용한 역 하프토닝 알고리즘)

  • Seo, Won-Kyo;Cho, Nam-Ik
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2015.11a
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    • pp.134-136
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    • 2015
  • 영상 역 하프토닝은 입력된 하프톤 영상으로부터 그레이 영상을 복원시키는 것으로, 하프톤 영상으로 처리하지 못하는 다양한 영상처리를 가능하게 해주는 방법이다. 기존의 참조표를 이용한 역 하프토닝 방법은 다양한 하프톤 영상과 원본 그레이 영상으로부터 추출한 정보를 이용해 입력 영상을 복원시키는데, 본 논문에서는 이를 바탕으로 하여 영상의 질을 전반적으로 향상시킬 수 있는 국부적인 이진 패턴 기반 참조표를 이용한 영상 역 하프토닝 방법을 제안한다. 먼저 참조표를 이용한 역하프토닝 방법을 이용해 영상을 복원한 후 각 픽셀에서의 국부 이진패턴을 계산하여 각 픽셀 값을 패턴에 따라 분류한다. 분류된 패턴 정보에 따라 국부 이진 패턴 기반 참조표를 생성하고 이를 통해 입력 하프톤 영상에 대한 역 하프토닝을 수행한다. 실험 결과는 제안하는 알고리즘이 오류 확산법에 의해 변환된 하프톤 이미지를 역 하프토닝 했을 때, 기존의 역 하프토닝 방법에 비해 더 나은 PSNR을 달성하는 것을 보인다.

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Performance Analysis for Beamformer of Adaptive Array Antenna in W-CDMA Communication System (W-CDMA 통신 시스템에서 적응배열안테나의 Beamformer 성능분석)

  • 이정길;홍상완;이병섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.6B
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    • pp.1127-1135
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    • 2000
  • The beamforming procedure in Adaptive Array Antenna System is affected by signal degradation and data rate due to DS-CDMA characteristics. Until this time, a lot of techniques are suggested to overcome this problems. This paper shows the simulation result about the beamforming performance of symbol level system that process slow data rate, compensated signal by despreading procedure in front of beamformer, and that of chip level system that process chip level signal without it. we analysis the performance using MSE, beam pattern, scattering points of beamformer output. chip level system is superior to symbol level system in time varying channel, while the performance of them didn't have difference in static channel.

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Performance of Multiple Order Selection Combining RAKE receiver in Multi-bandwidth CDMA System (다중 대역 확산 CDMA 시스템에서의 다중 선택 결합 RAKE 수신기의 성능 분석)

  • 권순일;홍인기
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.5A
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    • pp.593-601
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    • 2000
  • In a multi-bandwidth CDMA system, the performance of multiple order selection combining rake receivers are analyzed according to the spreading bandwidth of the system and the delay spread of the Rayleigh fading channel. The results for various channel environments indicate a tradeoff between total received signal energy and multipath fading immunity. Increasing the occupied bandwidth of the system(wide-bandwidth spreading) gives better performance for small delay spread environments, while gathering more energy(narrow-bandwidth spreading)gives better performance for large delay spread environments. It is shown that the performance difference between low and high order selection combining grows larger as the spreading bandwidth increases. It is also noted that performance degrades by increasing the bandwidth above a certain point and the optimum spreading bandwidth for each channel environment decreases as the delay spread of the channel increases.

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