• 제목/요약/키워드: Compared and analyzed

검색결과 21,012건 처리시간 0.049초

비터비 검파기를 이용한 2-h CPM의 차동 복조에 관한 연구 (A Study on the Differential Demodulation of 2-h CPM using Viterbi Detector)

  • 홍희식;한영열
    • 한국통신학회논문지
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    • 제16권11호
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    • pp.1095-1102
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    • 1991
  • 본 논문에서는 2-h CPM의 차동 복조 방식을 제안하고 이에 따른 오율 성능을 분석한다. 차동 복조에 적합한 변조지수 집합을 도출하고 이로부터 얻어진 변조지수에 따른 전력 스펙트럼을 구하여 기존의 MSK와 OPSK등과 비교,분석하였다. 또한 제안된 차동 검파기에 의한 오율 성능과 2-h CPM의 차동 복조식 비터비검파기를 적용시켜 얻은 오율 성능 등을 비교, 분석하였다.

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빗방울의 형태에 따른 산란특성 해석 및 강우감쇄 계수 추정 (The Analysis of Scattering Characteristics of Raindrops and Estimation of Specific Rain Attenuation for Different Drop Shapes)

  • 황정환;백정기;김양수;김영민;최용석;이주환;박세경
    • 한국전자파학회논문지
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    • 제10권5호
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    • pp.701-710
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    • 1999
  • To predict rain attenuation accurately, we must know scattering characteristics of rain-drops for real drop shapes. In this paper, the scattering characteristics of rain-drops are analyzed by an analytical model, and the differences in the characteristics of the forward scattering amplitudes for three different rain-drop shapes are compared. Using the results for the Pruppacher-Pitter's real rain-drop shaper, the specific rain attenuation in domestic environment is predicted, and the difference from the ITU-R model is compared and analyzed.

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Prelaunch Radiometric Performance Analysis of Ocean Scanning Multi-spectral Imager (OSMI)

  • Cho, Young-Min
    • 대한원격탐사학회지
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    • 제16권2호
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    • pp.135-143
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    • 2000
  • Ocean Scanning Multispectral Imager (OSMI) is a payload on the Korean Multi-Purpose SATellite (KOMPSAT) to perform global ocean color monitoring for the study of biological oceanography. HOMPSAT was launched 21 December 1999. The radiometric performance of OSMI is analyzed for various gain settings in the viewpoint of the instrument developer for OSMI calibration and application based on its ground performance data measured before launch. The radiometric response linearity and dynamic range are analyzed and the dynamic range is compared with the nominal input radiance for the ocean and the land. The noise equivalent radiance (NER) corresponding to the instrument radiometric noise is compared with the radiometric resolution of signal digitization (1-count equivalent radiance). The best gain setting of OSMI for ocean monitoring is recommended. This analysis is considered to be useful for the OSMI mission and operation planning, the OSMI image data calibration, and users' understanding about OSMI image quality.

천연색 항공영상을 이용한 지형요소 반자동 추출에 관한 연구 (A Study on Semi-automatic Feature Extraction Using False Color Aerial Image)

  • 김감래;김경록;전호원
    • 한국측량학회지
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    • 제19권2호
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    • pp.109-115
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    • 2001
  • 최근 수치사진측량시스템의 도입으로 수치정사영상의 활용도가 높아지고 있으며, 이에 따라 수치정사영상으로부터 지형지물의 반자동 또는 자동 추출에 관한 연구가 대두되고 있지만, 최근 많은 연구보고서에 의하면 흑백항공사진에서의 지형지물을 판단하거나 속성인식에 한계가 있음을 알 수 있다. 본 연구에서는 천연색 항공사진 영상을 흑백항공사진 영상과 비교, 분석하여 천연색 항공사진 영상의 특성을 분석하였으며, 반자동으로 지형요소를 추출하는 알고리즘을 개발하였고, 추출한 지형요소를 국립지리원에서 제작하는 1:5,000 수치지형도와 비교하여 반자동으로 추출가능한 지형요소를 분석하였다. 이러한 결과를 토대로 천연색 항공사진영상을 이용한 지형요소 추출 가능성과 지형요소 추출시 문제점을 분석하였고, 향후 연구에 대한 방안을 제시하였다.

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자연하도 하구부에서 갈수시 양수에 의한 지하수 유독특성 및 취수능력 결정에 관한 연구 (Study on the Characteristics of Groundwater Movement Caused by Pumping During Drought Period and Estimation of Pumping Capacity in Natural River Estuary)

  • 안승섭;최윤영
    • 한국농공학회지
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    • 제39권6호
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    • pp.88-98
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    • 1997
  • In this study, pumping capacity in the area of natural river estuary is estimated by the quantitative analysis using finite element method. The study area is Iga-ri pumping station in the estuary of Seojung-chun which runs to the East coast. First of aH, hydraulic properties and effects of different seawater levels are analyzed in this area. Variations of groundwater level caused by pumping and properties of seawater intrusion are analyzed, then compared the case of reinforcing the existing intake weir with the case of setting up an weir at the upper stream. The observed data of groundwater drawdown caused by pumping during drought period and seawater intrusion are compared with results of the analysis done by groundwater model using finite element method, and it is found that both are similar. Accordingly, groundwater model used in this study reflects well the variation of groundwater level caused by pumping.

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BSCCO Tape 선재와 YBCO CC의 외부자장 각도에 따른 자화손실 특성비교 (Comparison of Magnetization Losses in BSCCO Tape and YBCO CC at Arbitrary Direction of External Magnetic Field)

  • 이지광;임형우;박명진;차귀수
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제54권12호
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    • pp.586-591
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    • 2005
  • Magnetization loss of high temperature superconductoring BSCCO tape and YBCO coated conductor(YBCO CC) is most important issue in the development of superconducting power devices. In this paper, the measured results of magnetization losses in BSCCO tape and YBCO CC are presented and compared with each other. Measurements of magnetization losses are performed under various angles of external magnetic field to consider the anisotropic characteristics of YBCO CC. Also, we present the compared results of magnetization losses measured at arbitrary directional magnetic fields and analyzed with perpendicular magnetic field components of those. The results show that magnetization loss of YBCO CC agree well with the analyzed value by it's perpendicular magnetic field component, but BSCCO tape is not.

2차원 유한요소 해석을 이용한 고속용 마그네틱 기어의 형상에 따른 특성 해석 (Characteristic Analysis of High Speed Coaxial Magnetic Gear by Two-Dimensional Finite Element Analysis)

  • 이정인;신경훈;방태경;이상화;최장영
    • 전기학회논문지
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    • 제68권1호
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    • pp.36-43
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    • 2019
  • In this paper, the characteristics of the coaxial magnetic gear according to the shape of the same gear ratio are analyzed using the two - dimensional finite element analysis. The rotor shape is SMCMG, CPCMG and RCMG. After this we analyzed the characteristics according to three shapes. Also, the amount of permanent magnet used in each shape was compared. Next, characteristics analysis of the magnetic gear according to the shape at the same torque was performed. And the total weight and efficiency of the magnetic gears were compared and verified.

화염 불안정성에 따른 개선된 이미지 처리 기법을 활용한 디젤-바이오디젤 혼합 연료 액적의 연소 특성 (The Combustion Characteristics of Diesel-Biodiesel Blended Fuel Droplets Using the Modified Image Processing Method According to Flame Instability)

  • 최주환;임영찬;서현규
    • 한국분무공학회지
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    • 제26권3호
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    • pp.142-148
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    • 2021
  • The objective of this study is to analyze the basic flame behavior characteristics using the single fuel droplet combustion of diesel, palm-based biodiesel, and canola-based biodiesel. The results were compared and analyzed through the post processed image, which was applied the threshold level for removing noise in the raw image. The raw image was taken by a high-speed camera during the entire combustion process. At the same time, the maximum flame length, which was measured by the application code of the MATLAB program, the ignition delay, and the combustion period were compared and analyzed.

SMS 압축성형공정의 3차원 유한요소해석 (Three-Dimensional Finite Element Analysis of compression Molding of Sheet Molding Compound)

  • 김수영;임용택
    • 소성∙가공
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    • 제4권1호
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    • pp.39-47
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    • 1995
  • The compression molding of SMC (sheet molding compund) at room temperature was analyzed based on rigid-viscoplastic approach by three dimensional finite element program. The developed program was tested by solving the three dimensional compression of wedge type specimens of aluminum alloys at various processing conditions. The simulation results were compared well to the experimental results available in the literature. based on this comparison the program was proved to be valid and was further applied in solving compression molding of SMC, which is a thermosetting material reinforced with chopped fiber glass. To investigate the effects of friction conditions and mold closing speeds for compression molding of SMC charge at room temperature, compressions of the cylindrical and rectangular shaped SMC were analyzed for various friction conditions and mold closing speeds. The calculated load values were compared to the experimental results for the compression molding of cylindrical specimen.

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실험에 의한 음성·음악 분류 특징의 비교 분석 (Comparison & Analysis of Speech/Music Discrimination Features through Experiments)

  • 이경록;류시우;곽재영
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2004년도 추계 종합학술대회 논문집
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    • pp.308-313
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    • 2004
  • 본 논문에서는 각 특징 파라미터 조합의 음성/음악 분류 성능을 비교 분석하였다. 음향신호는 3가지(음성, 음악, 음성+음악)로 분류하였다. 본 실험에서는 분류 특징으로 멜캡스트럼, 에너지, 영교차 3가지 형태가 사용되었다. 음성/음악 분류 성능이 가장 좋은 특징간의 상호 조합을 비교 분석하였다. 실험결과 멜캡스트럼, 영교차 조합이 가장 좋은 결과(음성: 95.1%, 음악: 61.9%, 음성+음악: 55.5%)를 보인다는 것을 확인할 수 있었다.

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