• Title/Summary/Keyword: 곡선근사

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HDR Image Acquisition from Two LDR Images (두 장의 LDR 영상을 이용한 HDR 영상 취득 기법)

  • Park, Tae-Jang;Park, In-Kyu
    • Journal of Broadcast Engineering
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    • v.16 no.2
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    • pp.247-257
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    • 2011
  • In this paper, we propose a scene adaptive method to obtain two LDR images with proper shutter speeds which capture the irradiance of scene effectively. The proposed method adaptively selects two shutter speeds across the video frame even when the illumination varies continuously. For the performance evaluation, we compute the PNSR to the ground truth which is obtained by the state-of-the-art HDR imaging method. It shows that the proposed method is able to select approximately optimal shutter speeds while avoiding the exhaustive search of every possible pair of shutter speeds.

Parabolic mirror test using Computer Generated Hologram (Computer Generated Hologram을 이용한 포물명경 형상측정)

  • 김성하;곽종훈;최옥신;송재봉;이윤우;이인원
    • Korean Journal of Optics and Photonics
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    • v.11 no.2
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    • pp.80-84
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    • 2000
  • Parabolic almninium mlITOr of m.5('||'&'||'cent; 50 nun) was fabncated by a diamond tummg machine. Computer generated hologram (CGH) for the test of parabolic mirror was encoded by binary phase hologram Approximation of curved fringe to line was made by staircase encoding. After fringe data 1ransformed mto a Post Scnpt file. magnified master CGH was printed by a laser printer, and then it reduced to the photographIc film. Parabolic mirror was tested by Twyman-Green interferometer with CGH at VIewing arm. Its experimental result was compared with those of surface profile and auto-collimatIon test, and then the errors were analyzed.

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Measurements and Statistical Modeling of Electromagnetic Noise from Electric Train (도시전철에서 발생한 전자파잡음의 측정 및 통계적 모형)

  • 심환우;윤현보;백락준;우종우
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.6 no.7
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    • pp.37-47
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    • 1995
  • In this paper, we have measured eletromagnetic noises from eletcric trains and the measurment data are treated statisticlly for monig. In order to measure the noise of electric tran, we set up an automatic measuring system andd measured the magnetic field over 9 kHz ~ 30 MHz range and electric field over 30 MHz - 1, 000 MHz range. The computer controlled measurint system yields efficiently experimental APD (Amplitude Probability distribution) data each of national rail road and subway train. The measured APD curves are analysed in terms of sensitivity study of Middleton's model through 6-parameter variation. Optimal parameters are obtained from measured data using Composite Approximation Algorithm.

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Design and Implementation of Music Information Retrieval System (선율을 이용한 음악정보 검색 시스템의 설계 및 구현)

  • Jee, Jeong-Gyu;Oh, Hey-Sock
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.1
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    • pp.1-11
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    • 1998
  • This paper describes design and implementation of the system that is used to efficiently retrieve music information at a digital music library. Unlike typical music information retrieval systems, this system allows the user to sing a part of the melody through the microphone which he/she wants to find rather than using title, composer or the subject catalog to search. The system then recognizes the musical notes information through the signal processing of the sounds of the entered melody, and the intervals contour is created based on this information and used as a search pattern. By running the proposed notes string search algorithm that uses the musical notes information processed with the user input, and it produces the approximate search results. Therefore, users are able to retrieve and appreciate the music whenever he/she can sing any portion of the desired music.

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Measurement of Absorption and Scattering Coefficients of Biological Tissues by Time-Resolved Reflectance Method (시간 분해 반사율에 의한 생체조직의 흡수계수와 산란계수 측정)

  • Jeon, Kye-Jin;Park, Seung-Han;Kim, Ung;Yoon, Gil-Won
    • Journal of Biomedical Engineering Research
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    • v.18 no.4
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    • pp.499-505
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    • 1997
  • A non-invasive technique to measure absorption and scattering coefficients was investigated The reflected backscattered light from the surface of phantom and biological tissue was obtained by using a time-correlated single photon counting system in pico-second time domain. The absorption and scattering coefficients were acquired by the time of peak and asymptotic behavior of the time-resolved reflectance curve and agreed well the ones that is obtained with deconvolution method It was found that the approximation method was good for biological medium to calculate optical properties due to its convenience and accuracy.

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Responses of a roll-pitch coupled nonlinear system to the primary resonance of the roll mode (횡동요 모드와 주공진 된 횡-종동요연성 비선형계의 응답)

  • 오일근
    • Journal of Ocean Engineering and Technology
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    • v.11 no.3
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    • pp.107-115
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    • 1997
  • 비성형 동력학계로 모델링된 부유수송체의 동적응답을 조사하고 그 운동의 안정성을 해석하였다. 종동요 모우드의 고유주파수가 횡동요 모우드의 고유주파수의 두배가 되는, 즉, 2:1 내부공진 혹은 자기계수공진인 조건하에서, 이부유수송체는 한 운동 모우드의 직접가진에 의해 간접가진된 다른 모우드가 대진폭 응답을 보일 수 있음을 밝혔다. 또항, 종동요 모우드의 감쇠력은 비교적 넓은 범위의 운동에 대해 선형적임에 반해, 횡동요 모우드의 감쇠력은 점성의 영향이 대단히 커서 비선형성이 대단히 강한 것으로 알려져 왔다. 이 문제를 수학적으로 모델링하기 위하여, 종동요 모우드의 운동방정식에는 선형및 제곱형의 합의 형태인 감쇠력 모형을 사용하였다. 다중척도법을 사용하여 이 두가지 운동 모우드의 주기적 응답및 그의 안정성에 미치는 제곱형 비선형 횡동요 감쇠력의 영향을 밝혔다. 조우주기가 횡동요 모우드의 고유주기와 근사한 경우에 대하여 이 비선형계의 응답을 구하고 주파수-응답 곡선으로 나타내었다.

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Parameter Extraction of a Lithium-ion Battery for EV/PHEV by the use of MATLABⓇ/SimulinkⓇ (MATLABⓇ/SimulinkⓇ 기반 EV/PHEV용 리튬 이온 배터리 모델 파라미터 추출)

  • Kim, Hong-Seok;Hong, Seung-Gun;Jeon, Joon-Young;Choe, Gyu-Yeong;Lee, Byoung-Kuk
    • Proceedings of the KIPE Conference
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    • 2010.11a
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    • pp.351-353
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    • 2010
  • 본 논문에서는 쉽고 빠르게 정확한 리튬 이온 배터리 모델을 구현할 수 있는 방법을 제시하고 있으며, 구현된 모델을 MATLAB(R)/Simulink(R)환경에서 검증한다. 모델을 구현함에 있어서 절차를 간소화하기 위해 비선형 개방 전압은 배터리 충전 및 방전 전압의 평균으로 근사하고, 배터리 내부 비선형 파라미터는 방전 초기에 발생하는 과도응답을 측정한 이산 데이터를 곡선 접합하여 구한다. 구현된 모델을 이용하여 시뮬레이션을 하고 이를 실험 데이터와 비교해본 결과, 평균 절대오차는 기존 연구보다 0.1% 낮은 0.091%로 측정되었다. 측정된 오차의 수준은 본 논문에서 제안한 방법이 파라미터 추출에 필요한 시간을 단축하고 시뮬레이션 모델을 쉽게 구현 가능하게 함에도 불구하고 여전히 리튬 이온 배터리의 출력 특성을 정확하게 예측함을 보여준다.

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Dose Calculation for the Buckler Remote Afterloading System (Buchler 강내조사장치의 선량계산에 대한 연구)

  • Chung Weon Kuu;Kim Soo Kon;Kang Jeong Ku;Lee Jeong Ok;Moon Sun Rock;Kim Seung Kon
    • Radiation Oncology Journal
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    • v.14 no.3
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    • pp.247-253
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    • 1996
  • Purpose : The dose calculation program for the Buckler type remote after-loading system was developed. This program also can be used to calculate dose for various sealed sources. Materials and Methods : We determined the source length and distribution by dividing the program disk to 72 points. The dose rate for the each program disk and source was calculated. The dose rate table for the xy coordinate was established. The dose rate for the interesting points of the patient were calculated by using this table, We also made isodose curve from this calculations. Results : The storage size for the dose rate table were increased. But the calculation of the dose rate for the patient were carried out rapidly. So we could get real time calculation. Conclusion : By using this program, we could calculate the dose rate for the various points of the patient quickly and accurately. This program will be useful for the treatment with various linear sources.

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The Practice of Bending Deflection using Non-destructive MOE of Glulam (비파괴 탄성계수를 이용한 집성재의 휨변형 예측)

  • Park, Jun-Chul;Hong, Soon-Il
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.1
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    • pp.48-55
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    • 2009
  • In the glulam beam deflection it is necessary to check the reliability of theory formula, because of wood anisotropy and wood qualities (knot, slop of grain). In this experiment, when bending stress occurred on glulam, practice deflection of glulam measuring with AICON DPA-Pro 3D system were compared with prediction deflection calculated as substituting MOE through non-destructive testing and static MOE through bending test in differential equation of deflection curve. MOE using ultrasonic wave tester of laminae, MOE using natural frequencies of longitudinal vibrations ($E_{cu}$, $E_{cf}$), MOE using ultrasonic wave tester of glulam ($E_{gu}$) and MOE using natural frequencies of longitudinal vibrations ($E_{gf}$) were substituted in this experiment. When practice deflection measured by 3D system was compared with prediction deflection calculated with differential equation of deflection curve, within proportional limit the ratio of practice deflection and prediction deflection was similar as 1.12 and 1.14, respectively. Deflection using ultrasonic wave tester was 0.89 and 0.95, Deflection using natural frequencies of longitudinal vibrations was 1.07 and 1.10. The results showed that prediction deflection calculated by substituting using non-destructive MOE of glulam having anisotropy in differential equation of deflection curve was agreed well with practice deflection.

Application of Analysis Models on Soil Water Retention Characteristics in Anthropogenic Soil (인위적으로 변경된 토양에서의 수분보유특성 해석 모형의 적용)

  • Hur, Seung-Oh;Jeon, Sang-Ho;Han, Kyung-Hwa;Jo, Hee-Rae;Sonn, Yeon-Kyu;Ha, Sang-Keun;Kim, Jeong-Gyu;Kim, Nam-Won
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.823-827
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    • 2010
  • This study was conducted to assess the propriety of models for soil water characteristics estimation in anthropogenic soil through the measurement of soil water content and soil water matric potential. Soil profile was characterized with four different soil layers. Soil texture was loamy sand for the first soil layer (from soil surface to 30 cm soil depth), sand for the second (30~70 cm soil depth) and the third soil layers (70~120 cm soil depth), and sandy loam for the fourth soil layer (120 cm < soil depth). Soil water retention curve (SWRC), the relation between soil water content and soil water matric potential, took a similar trend between different layers except the layer of below 120 cm soil depth. The estimation of SWRC and air entry value was better in van Genuchten model by analytical method than in Brooks-Corey model with power function. Therefore, it could be concluded that van Genuchten model is more desirable than Brook-Corey model for estimating soil water characteristics of anthropogenic soil accumulated with saprolite.