• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 전기설비
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• pp.89-90
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• 2006

Recent earth systems not only make earth resistance decreased by installing earth electrode but also are demanded by earth construction for the protection of human life and equipments through total investigation about circumstances. Layer constructions in Jeju island consist of multi-layer of scoria, rocks and shale except clay layers on the surface, which needs the construction of the coring earth electrode suitable in the condition of the area. For this reason, we've used the coring earth electrode. But the coring earth electrode is expected to slow down the performance of this equipment according to the progress of time changing the effects. It is also applied for the stability of earth system construction and management after the construction work analyzing the condition of the earth system. Therefore, this is actually focused on the analysis on measuring the earth resistance and the soil resistivity that cover the range where the remarkable contrast can be expected to be seen in the layer structures.

• 대한원격탐사학회지
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• 제35권1호
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• pp.195-201
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• 2019

The Outgoing Longwave Radiation (OLR) is an important satellite-driven variable for understanding the Earth's energy budget balance. The geostationary OLR retrievals require angular and spectral integration using an empirical equation for irradiance flux-to-OLR from a regression analysis, which determines the accuracy of the narrowband satellite-based OLR. We selected homogeneous pixels which is satisfied less temporal-spatial variability of cloud, on three infrared channels (6.7, 10.8, $12.0{\mu}m$) of the first multipurpose geostationary satellite in Korea, namely the Communication, Ocean and Meteorological Satellite/Meteorological Imager (COMS/MI). Multiple regression analysis was performed to retrieve OLR with improved accuracy using selected parameters based on theoretical and physical significance. This algorithm yielded retrieval with higher accuracy than broadband-based OLR retrieval: RMSE of 10.54 to $3.81W\;m^{-2}$, and bias of -8.49 to $-0.07W\;m^{-2}$.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.467-470
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• 2006

모든 건설공사의 기초를 이루는 토공사는 건설기계의 사용으로 오늘날까지 많은 발전을 이루어 왔으나, 공기단축 및 원가절감에 있어 중요한 요소인 토공장비의 적정한 조합시공방안이 체계적으로 정립되어 있지 않고 경험에 의존하여 수행되는 상태로 관련분야에 대한 체계적인 연구가 필요한 실정이다. 합리적인 기계화 토공은 공사에 투입될 장비의 성능 및 특성, 공사의 종류, 규모 및 주위의 여건 등을 사전에 철저히 파악해야 하며, 사용 가능한 몇 가지 규격의 장비를 선정하여 최적조합시공을 계획해야 한다. 이에 본 연구에서는 시스템 다이내믹스 기법을 활용하여 토공작업의 여러 단계 중 기계화 토공장비의 굴착 후 적재 및 운반단계를 대상으로 토공장비의 최적조합시공에 의한 토공량 산정 모형을 구축한다. 이 연구의 결과로 도출되는 토공장비의 최적조합시공모형은 토공계획을 담당하는 관리자가 토공장비의 선정에 있어 최단시간에 합리적인 판단을 하게 해줄 것으로 기대된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 가을 학술발표회 논문집
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• pp.323-328
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• 2001

In the ordinary reinforced earth wall, which was constructed by incremental construction method, the horizontal deformation of the facing due to the compaction induced horizontal earth pressure was unavoidable. Thus the KOESWall system which are adopted the isolated construction method was developed by I&S Eng. Co., Ltd. in 1999. Due to its systematical feature, KOESWall system is able to minimizes the horizontal deformation of reinforced wall effectively and it can be used as temporary structures more economically without the lacing block. In this report, it is shown that the concept and case histories of KOESWall system as a retaining structures.

• 대한원격탐사학회지
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• 제37권1호
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• pp.85-95
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• 2021

Recently, as data mining and artificial neural network techniques are developed, analyzing large amounts of data is proposed to reduce the dimension of the data. In general, empirical orthogonal function (EOF) used to reduce the dimension in the ocean data and recently, Self-organizing maps (SOM) algorithm have been investigated to apply to the ocean field. In this study, both algorithms used the monthly Sea level anomaly (SLA) data from 1993 to 2018 around the East Asia Coasts. There was dominated by the influence of the Kuroshio Extension and eddy kinetic energy. It was able to find the maximum amount of variance of EOF modes. SOM algorithm summarized the characteristic of spatial distributions and periods in EOF mode 1 and 2. It was useful to find the change of SLA variable through the movement of nodes. Node 1 and 5 appeared in the early 2000s and the early 2010s when the sea level was high. On the other hand, node 2 and 6 appeared in the late 1990s and the late 2000s, when the sea level was relatively low. Therefore, it is considered that the application of the SOM algorithm around the East Asia Coasts is well distinguished. In addition, SOM results processed by SLA data, it is able to apply the other climate data to explain more clearly SLA variation mechanisms.

• 대한원격탐사학회지
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• 제37권1호
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• pp.161-167
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• 2021

This paper presents the method to quantitatively evaluate the uncertainty of the semi-empirical Bidirectional Reflectance Distribution Function (BRDF) model for Himawari-8/AHI. The uncertainty of BRDF modeling was affected by various issues such as assumption of model and number of observations, thus, it is difficult that evaluating the performance of BRDF modeling using simple uncertainty equations. Therefore, in this paper, Monte-Carlo method, which is most dependable method to analyze dynamic complex systems through iterative simulation, was used. The 1,000 input datasets for analyzing the uncertainty of BRDF modeling were generated using the Second Simulation of a Satellite Signal in the Solar Spectrum (6S) Radiative Transfer Model (RTM) simulation with MODerate Resolution Imaging Spectroradiometer (MODIS) BRDF product. Then, we randomly selected data according to the number of observations from 4 to 35 in the input dataset and performed BRDF modeling using them. Finally, the uncertainty was calculated by comparing reproduced surface reflectance through the BRDF model and simulated surface reflectance using 6S RTM and expressed as bias and root-mean-square-error (RMSE). The bias was negative for all observations and channels, but was very small within 0.01. RMSE showed a tendency to decrease as the number of observations increased, and showed a stable value within 0.05 in all channels. In addition, our results show that when the viewing zenith angle is 40° or more, the RMSE tends to increase slightly. This information can be utilized in the uncertainty analysis of subsequently retrieved geophysical variables.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2011년도 학술대회 및 정기총회
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• pp.145-146
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• 2011

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2011년도 학술대회 및 정기총회
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• pp.135-136
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• 2011

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.248-250
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• 2003

Thermal analysis is performed to protect the propulsion system of low-earth-orbit earth observation satellite from unwanted thermal disaster like propellant freezing. To implement thermal design adequately, heater powers for the propulsion system estimated through the thermal analysis are decided. Based on those values anticipated herein, the average power for propulsion system becomes 22.02 watts when the only one redundant catalyst bed heater is turned on. When for the preparation of thruster firing, 25.93 watts of the average power is required. All heaters selected for propulsion components operate to prevent propellant freezing meeting the thermal requirements for the propulsion system with the worst-case average voltage, i.e. 25 volts.

• 한국과학교육학회지
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• 제29권8호
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• pp.963-977
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• 2009

이 연구의 목적은 지구계 교육의 학습자로서 대학생들의 지구계 순환에 대한 인식을 밝혀 교육에의 시사점을 찾는 것이다. 지구과학 교양 수업을 수강하는 62명의 비과학 전공 대학생들을 대상으로 8주 동안 창의적 이야기 쓰기 활동을 실시하였다. 창의적 이야기는 스토리맵 그리기 방법으로 순환의 구성 개념과 유형을 분석하여 범주화 하였다. 지구계의 순환 구성 개념은 32가지로 매우 다양하게 표출되었고, 순환 유형은 원형과 복합형이 다수였으나 일부 사례는 순환 고리를 완성하지 못한 가지형과 선형으로 표현되었다. 지구계 순환에 대한 대학생들의 인식은 자연-생물계에 편향되어 있으며, 자연-생물계와 인간계의 3 범주를 모두 인식한 사례는 30% 미만으로 나타났다. 지구계 교육을 통해 인간 활동에 의한 피드백의 영향을 인지할 수 있도록 순환을 소재로 교수 내용을 다양화 하고, 학습자의 시스템 사고를 지원해야 하겠다.