• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.145-145
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• 2015

본 연구에서는 SWAT(Soil and Water Assessment Tool) 모형을 이용하여 고랭지 농업 지역인 해안분지유역($63km^2$)을 대상으로 RCP 기후변화 시나리오에 따른 미래 수문순환 전망을 평가하였다. 모형의 보정(2009년-2010년) 및 검증(2011년)은 3지점의 실측된 유출량을 활용하여 실시하였다. 모형의 보정 및 검증 결과 결정계수($R^2$)는 X.XX-X.XX이고, Nash-Sutcliffe 모형 효율(NSE)는 X.XX-X.XX으로 분석되어 신뢰성 있는 유출량 모의 결과를 나타내었다. 미래 기후변화 시나리오는 기상청에서 제공하는 HadGEM3-RA 모형의 RCP 4.5 및 8.5 자료를 수집하였다. 다음으로 과거 13년(1999년-2011년, Baseline period)의 기상자료를 기준으로 편이보정(Bias Correction)기법을 이용하여 오차보정 후, SWAT 모형에 적용하여 2040s(2020년-2059년) 및 2080s(2060년-2099년) 기간에 대해서 분석하였다. 그 후, 수문요소인 증발산, 토양수분, 지표유출, 중간유출, 회귀유출 및 하천유출량의 변화량을 분석하여 고랭지 농업 유역의 기후변화에 따른 미래 수문순환을 전망하였다.

• Korean Journal of Remote Sensing
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• v.37 no.5_2
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• pp.1259-1268
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• 2021

The 2nd Geostationary Ocean Color Imager (GOCI-II) is the successor to the Geostationary Ocean Color Imager (GOCI), which employs one near-ultraviolet wavelength (380 nm) and eight visible wavelengths(412, 443, 490, 510, 555, 620, 660, 680 nm) and three near-infrared wavelengths(709, 745, 865 nm) to observe the marine environment in Northeast Asia, including the Korean Peninsula. However, the multispectral radiance image observed at satellite altitude includes both the water-leaving radiance and the atmospheric path radiance. Therefore, the atmospheric correction process to estimate the water-leaving radiance without the path radiance is essential for analyzing the ocean environment. This manuscript describes the GOCI-II standard atmospheric correction algorithm and its initial phase validation. The GOCI-II atmospheric correction method is theoretically based on the previous GOCI atmospheric correction, then partially improved for turbid water with the GOCI-II's two additional bands, i.e., 620 and 709 nm. The match-up showed an acceptable result, with the mean absolute percentage errors are fall within 5% in blue bands. It is supposed that part of the deviation over case-II waters arose from a lack of near-infrared vicarious calibration. We expect the GOCI-II atmospheric correction algorithm to be improved and updated regularly to the GOCI-II data processing system through continuous calibration and validation activities.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.12
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• pp.67-74
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• 2006

An unsteady blockage-correction method utilizing wall pressure distribution on the test section has been developed for the wall interference correction of a closed test-section subsonic wind tunnel. The pressure distribution along the test section wall was decomposed into Fourier series and a quasi-steady method based on a measured-boundary-condition method was applied to each Fourier coefficient. The unsteady correction for a complete test period was accomplished by recombining each corrected terms. The present method was validated by appling computed unsteady flows over a cylinder and an oscillating airfoil in the test sections. The corrected results by the present method agreed well with free-air condition.

• Journal of the Korea Convergence Society
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• v.9 no.3
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• pp.15-21
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• 2018

The ocean drifter is a device for observing the ocean weather by floating off the sea surface. The data observed through the drifter is utilized in the ocean weather prediction and oil spill. Observed data may contain incorrect or missing data at the time of observation, and accuracy may be lowered when we use the data. In this paper, we propose a data correction model using recurrent neural networks. We corrected data collected from 7 drifters in 2015 and 8 drifters in 2016, and conducted experiments of drifter moving prediction to reflect the correction results. Experimental results showed that observed data are corrected by 13.9% and improved the performance of the prediction model by 1.4%.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.267-272
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• 2005

최근 항공레이저스캐닝(ALS)은 높은 정확도와 경제성을 이유로 지형정보를 획득하는 탁월한 수단으로 주목받고 있다. ALS에 의해 수집되는 고도자료는 DSM, DEM 제작에 유용하게 이용된다. ALS는 고도자료 이외에 지표면의 물질적 특성을 나타내는 반사강도를 획득한다. 그러나 반사강도는 노이즈로 인해 널리 이용되지 못하고 있으며, 노이즈의 주원인은 반사각으로 알려져 있다. 따라서 본 연구는 센서 위치정보와 ALS 고도자료를 이용하여 반사각을 이용하여 반사강도를 보정하는 방법을 제안하였다 여기에는 ${\theta}$의 각도로 입사한 레이저의 강도는 수직으로 입사한 레이저의 강도보다 $sin{\theta}$만큼 감소한다는 물리학적 원리가 이용되었다 반사각은 지표면과 레이저가 이루는 각으로, 센서와 측정점 사이의 각과 지표면의 경사각의 두 단계로 나누었다. 방법의 적합 여부를 확인하기 위해 적외선 영역에서 분리도가 잘 이루어지는 아스팔트, 휴경지(토양), 콘크리트, 수목의 네 가지 검증영역을 선정하여 보정된 반사강도와 보정 전의 반사강도를 비교하였다. 모든 영역에서 반사강도가 증가하였으며 특히 콘크리트와 수목에서의 증가가 두드러졌다. 보정을 통해 네 영역에서 반사강도의 분리도가 향상됨을 물론 그 크기가 '아스팔트<토양<콘크리트<수목'으로 나타나는 이론적인 경향과 유사함을 확인할 수 있다.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.137-142
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• 1998

이 연구의 목적은 혼합핵연료 장전노심에서와 같이 스펙트럼이 상이한 인접핵연료의 영향으로 나타나는 노드내 스펙트럼 이력효과를 보정해 주고자 하는 것이다. 이를 위해 이 연구에서는 노드내 13개 지역에서 국부적 미시연소를 수행하여 스펙트럼 이력이 각각 다른 13 개의 독립적인 핵단면적을 구하였고 이로부터 노드내 핵단면적의 분포를 다항식으로 근사하였다. 스펙트럼 이력구배 효과의 보정은 노드내 중성자속 가중평균 핵단면적과 노드내 핵단 면적의 분포에 따른 불연속인자로 보정하였다. 이 스펙트럼 이력구배 효과 보정방법을 혼합 핵연료와 우라늄핵연료가 Checkerboard 형으로 무한히 장전된 경우에 대하여 검증계산을 수행하여 참조해인 CASMO-3 결과와 비교하였다. 스펙트럼 이력분포가 고려되지 않은 경우는 연소도 40 MWD/kgHM에서 노심 반응도에서 약 0.38%, 봉출력에서 최대 11.2 %, 평균 4.3%의 오차를 보였으나 스펙트럼 이력분포를 반영함으로서 노심 반응도에서 0.12 %, 봉출력에서 최대 4.9%, 평균 1.3%의 오차를 보였다.

• Journal of Advanced Navigation Technology
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• v.19 no.1
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• pp.15-21
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• 2015

WA-DGNSS is a system to service for users using a satellite which received correction data from ground station that calculates the relative errors of the tracked GNSS signals and sends to a satellite. Users are guaranteed the reliability of the GNSS signal and the accuracy of positioning. ICAO recommends the application of WA-DGNSS for the airplane taking off and landing process. In this paper, we suggests methods to verify of the pre-developed WA-DGNSS reference software constituting modules and an integration test process refer to the RTCA DO-278 which is a document for the development process of an aeronautics software. Also, we statistically verified the reference software test through our methods. And then, we confirmed to performance the function of the reference software properly.

• Korean Journal of Remote Sensing
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• v.27 no.2
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• pp.99-105
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• 2011

This research presents the correction method to correct the location error of cloud caused by parallax error, and how the method can reduce the position error. The procedure has two steps: first step is to retrieve the corrected satellite zenith angle from the original satellite zenith angle. Second step is to adjust the location of the cloud with azimuth angle and the corrected satellite zenith angle retrieved from the first step. The position error due to parallax error can be as large as 60km in case of 70 degree of satellite zenith angle and 15 km of cloud height. The validation results by MODIS(Moderate-Resolution Imaging Spectrometer) show that the correction method in this study properly adjusts the original cloud position error and can increase the utilization of geostationary satellite data.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.4
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• pp.41-53
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• 2018

This study developed the optimization method to correct the measured traffic volume of the expressway that minimizes the measurement error and satisfies the traffic balancing with TCS. For this purpose, the model constructed in this study was compared and verified with the true traffic volume. Verification result of the model, it was found that the measurement error is reduced when the measured traffic volume is corrected for the traffic volume balance. As a result of applying it to 40 links of the Kyoungbu expressway, the measured traffic volume was corrected by -8.1%~9.6% and the measurement error was decreased as much as the corrected traffic volume. This research is meaningful in improving the accuracy of the measured traffic volume of the expressway, while the scale and role of the expressway are increasing.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.4
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• pp.313-318
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• 2014

In this paper, we propose a method for correcting the measurement axis twist that occurs in the process of wearing and each estimation method of joint in which the inertial measurement unit based in health arm by the method of operation upper limb rehabilitation equipment of hemiplegic patients. In order to verify the proposed method, it is fitted with a inertial measurement unit of the upper arm and forearm of the experimenter left arm, verified by comparing actual joint angle is detected by photographing the arbitrary posture, the angle that the estimated joint. Then, it was verified by comparing the applied front / rear techniques for correcting the measurement axis twist. A result of the experiment, before applying the measurement axis twist correction, joint, after but each match rate showed a weak concordance rate in 89.16% and were corrected, measurement axis twist, each concordance rate of joint agreement of 93.28% I understand that it has been 4.12% improvement in the rate.