• Title/Summary/Keyword: 전파 특성

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Propagation Characteristics of Spatial Solitons in Nonlinear Ken Media (비선형 Ken 매질에서의 공간 솔리톤의 전파특성)

  • 최봉필;김재관;정제명;장호성
    • Proceedings of the Optical Society of Korea Conference
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    • pp.310-311
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    • 2003
  • 비선형 Kerr 매질에서 광파의 전파 특성을 해석하기 위해 지금까지 다양한 수치해석 방법들이 연구되어오고 있다 그중 FDTD 방식은 시간의 종속적인 Maxwell curl 방정식에 대해 어떠한 시간적, 공간적 근사를 사용하지 않고 광파의 전파 특성을 시뮬레이션하기 위해 유도되었기 때문에 산란과 같은 종축방향 불연속 문제나 비종축 파의 전파 특성 문제에 대해 보다 신뢰성 있는 해석 결과를 얻을 수 있으며, 비선형 Kerr 매질에서의 광파의 전파 특성에 대해서 보다 정확한 해석이 가능하다고 알려져 있다. (중략)

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Manufacturing of Sample Holder for the Property Analysis in Millimeter Wave Range (밀리미터파 전파특성 분석용 샘플홀더 제작)

  • Choi, Chang-Mook;Lim, Bong-Taeck
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.311-314
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    • 2010
  • 본 논문에서는 밀리미터파 대역 전파특성 분석용 샘플홀더 제작을 위하여 전파의 도파이론을 정립하고 밀리미터파 W-bnad(75 GHz ~ 110 GHz) 주파수 대역에 알맞은 도파관형 샘플홀더를 설계 및 실 제작하였다. 그리고 제작된 샘플홀더를 테스트하기 위하여 샘플시료를 제작하여 재료정수 및 전파흡수능을 측정하고 분석하였다. 분석결과 샘플시료 특성을 정확하게 측정할 수 있음을 확인하였으며, 향후 이 측정 샘플홀더는 밀리미터파 대역 전파특성 분석을 위해 매우 유용하게 쓰일 수 있을 것이다.

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UWB 통신 시스템의 전파 특성

  • 최상성
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.3
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    • pp.43-51
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    • 2002
  • UWB 무선 기술은 매우 좁은 폭의 펄스를 기저대역에서 직접 변조하여 전송함으로써 근거리에서 매우 높은 데이터 전송 특성과 정확한 거리 및 위치 추정을 위한 높은 해상도를 제공하며 다중경로에 따른 페이딩 영향에도 강인한 특성을 보인다. 또한 매우 넓은 대역폭에 걸쳐 기존의 무선 시스템과 비교하여 상대적으로 매우 낮은 스펙트럼 전력 밀도가 분포함으로 기존의 협대역 및 광대역 시스템과 상호 간섭 없이 주파수를 공유할 수 있는 새로운 무선 기술로 급부상되고 있다. 본 논문에서는 UWB 신호의 스펙트럼 전력 밀도 및 다중 경로 전파 특성을 분석 고찰함으로써 향후 무선통신 시장의 새로운 변화를 가져올 UWB 무선 기술의 전파 특성을 소개 하고자 한다.

Measurement of Radio Characteristics of Vehicular Communication Environments in Urban Areas and Implementation Issues (도심 차량통신환경에서의 전파특성 측정과 구현 이슈)

  • Cho, Woong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.9
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    • pp.1057-1062
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    • 2014
  • Vehicular communications can be applied for transmission of various safety messages or Intelligent Transportation Systems(ITS) applications by combining vehicle/road technology with Information and Communication Technology(ICT). In this paper, we represent measurement results of radio characteristics of vehicular communications using IEEE 802.11p based system in urban environments. Radio characteristics are based on the packet error rate (PER) and received spectrum mask. Using measurement results, we discuss implementation issues of vehicular communication systems for supporting reliable services.

Degradation Assessment of Thermoplastic Synthetic Resin Using Propagation Characteristics of Ultrasound (초음파 전파특성을 이용한 열가소성 합성수지의 열화 평가)

  • Jeon, Woo-Sang;Kim, Gi-Jin;Kwon, Sung-Duk
    • Journal of the Korean Society for Nondestructive Testing
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    • v.34 no.2
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    • pp.141-147
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    • 2014
  • A nondestructive ultrasonic technique was applied to evaluate the thermal characteristics and degradation of synthetic polymer resin (plastics) with better cost-effectiveness and functionality than glass and metal. Thermoplastic and transparent acrylic resin (PMMA) specimens were annealed at below the glass transition temperature ($T_g$), and the propagation characteristics (attenuation and velocity) were measured. The attenuation increased and the velocity decreased with thermal degradation. The results showed that the thermal aging of the specimens could be evaluated quantitatively and that the Tg could be evaluated qualitatively.

Analysis of Propagation Characteristics by Statistical Analysis in Domestic Atmospheric Environments (국내 대기 환경의 통계적 특성 분석을 통한 전파 특성 분석)

  • Choi, Moon-Young;Lee, Gil-Jae;Kim, Hyun-Soo;Pack, Jeong-Ki
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.6
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    • pp.698-705
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    • 2008
  • When electromagnetic waves propagate through atmosphere, waves are affected by various factors. Atmosphere normally consists of different molecular species, water vapours, rain, fog, snow and small suspended particles called aerosols. The distributions of atmosphere molecules, water vapours, rain rate, snowfall and aerosol are dependent on geometrical regions or environment. In order to predict propagation characteristics in atmospheric environment, statistical analysis of the relevant parameters such as temperature, humidity, atmospheric pressure, wind speed, areosol and rainfall is crucial. In this paper, we performed a long-term statistical analysis for the atmospheric parameters in domestic environments and analyzed the propagation characteristics through atmosphere based on that.

Performance Analysis of Cooperative Localization Algorithm Considering Wireless Propagation Characteristics (무선 전파특성을 고려한 협력 위치추정 알고리즘 성능분석)

  • Jeong, Seung-Heui;Oh, Chang-heon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.6
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    • pp.1511-1519
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    • 2010
  • In this paper, we proposed and analyzed a RSSI based cooperative localization algorithm considering wireless propagation characteristics in indoor and outdoor environments for wireless sensor networks, which can estimate the BN position. The conventional RSSI based estimation scheme has low precision ranging due to instability propagation characteristics by time variable. Hence, we implemented ray-launching simulator for analysis of propagation characteristics in 4 case, and experimented proposed localization scheme with 4 RN and 1 to 5 BN. Simulation results show that NLCA has estimation error as 2m-3.5m, however, proposed CLA/ECLA has 1.3m-2.5m/0.5m-1.2m by same environments. Therefore, if we can consider channel characteristics, the proposed algorithm provides higher localization accuracy than RSSI based conventional one.

Propagation Characteristics of Potential Tsunamis in Okinawa Trough (오키나와 트러프 잠재 지진해일 전파특성)

  • Kim, Jong-Hak;Choi, Weon-Hack;Bae, Jae-Seok;Yoon, Sung-Bum
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.3
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    • pp.268-276
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    • 2008
  • Potential tsunamis generated in Okinawa Trough were simulated for the investigation of the propagation characteristics in the southwestern sea of Korean Peninsula. Shallow waters in the continental shelf of East China Sea and deep waters in Okinawa Trough play an important role in the propagation characteristics of the tsunamis generated in this region. The propagation characteristics can be classified into two phases according to the stage of propagation. In the first phase, the tsunamis propagate both northeast and southwest along the deep water of the trough. In the second phase, the tsunamis enter the continental shelf of the East China Sea at right angles to topographic contour lines. Simulated results show that the tsunamis generated in the Okinawa Trough give a weak influence to the southern and western coasts of Korea due to the special topography of the southwestern sea of Korean Peninsula.

Discrete Ray Tracing Techniques for Wave Propagation Characteristic of Random Rough Surfaces (불규칙 조면의 전파 특성 해석을 위한 이산 광선 추적법)

  • Yoon, Kwang-Yeol
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.3
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    • pp.233-238
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    • 2010
  • In this paper, we have proposed discrete ray tracing method (DRTM) for numerical analysis of characteristics of electromagnetic propagation along 2D random rough surfaces. The point of the present method is to discretize not only rough surface but also ray tracing. The former helps saving computer memories and the latter does simplifying ray searching algorithm resulting in saving computation time. Numerical calculations are carried out for 2D random rough surfaces, and electric field distributions are shown to check the effectiveness of the proposed DRTM.

Prediction of Antenna Propagation Characteristic in Space Environment Using Ray Tracing Method (광선 추적법을 이용한 우주 환경에서의 안테나 전파 특성 예측)

  • Kim, ChangSeong;Park, Yong Bae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.11
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    • pp.1023-1026
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    • 2016
  • We calculate the propagation characteristic of antennas considering refractive indices of space environments. The effective indices of troposphere, stratosphere, and inonshpere are computed and the ray tracing method, geometrical optics, and Huygens' principle are used to estimate refracted and attenuated electromagnetic wave of space environment.