• Korean Journal of Environmental Biology
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• v.30 no.4
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• pp.287-306
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• 2012

Amphibian population declines globally. Environmental contamination by heavy metals has been suspected to the one of the reason for distinction of amphibian which has obligate aquatic life style during larval period. Amphibians have been widely accepted as animal model for the study of endocrine disruption in aquatic ecosystem at molecular as well as individual levels. There are increasing need for toxicological data in amphibians at multiple endpoints for management of contamination and development of safety guidelines. Here, we reviewed toxicological information about toxicity of heavy metals (arsenic, cadmium, chromium, copper, lead, mercury, nickel, zinc) on various end-point of amphibian.

• Aerospace Engineering and Technology
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• v.10 no.1
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• pp.193-200
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• 2011

The external disturbance torque acting on a low earth orbit spacecraft was analyzed. For the Earth pointing attitude, the maximum torque to the spacecraft is about $8.3{\times}10^{-4}$ Nms and the momentum accumulated for an orbit is about 1.4 Nms and for the Sun pointing attitude, the maximum torque to the spacecraft is about $1.6{\times}10^{-3}$ Nms and the momentum is accumulated about 3.0 Nms in the spacecraft body reference frame. The analysis results confirm that the size of magnetic torquer selected previously for the satellite is sufficient to manage the accumulated momentum by considering the dumping capacity for an orbit.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1546-1550
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• 2010

최근 IPCC에서는 제 4차 평가보고서를 통해 대기 속 이산화탄소 농도가 산업혁명 이전에 비해 2005년 기준 약 35% 증가하였으며, 지난 1세기 동안 지구 평균기온이 $0.74^{\circ}C$ 증가하였다고 발표하였다. 이러한 기후변화로 인해 야기된 홍수, 가뭄, 사막화, 생태계 혼란 등의 심각한 환경문제를 해결하고자 UN에서는 1992년 세계 환경 개발에 관한 리우 데 자네이로 정상회의에서 기후변화에 관한 기본협약을 체결하여 국제적인 대책을 마련하기 위해 노력하고 있다. 이 중 토지이용변화에 관한 연구는 기후변화를 야기하는 주요한 요인에 관한 연구로서 온실가스 증가와 생물종다양성, 수문학적인 변화 등을 파악하는 데 활용되고 있다. 따라서 기후변화에 대응하고 지속가능한 개발 정책을 수립하기 위해서는 다양한 경제학적, 사회학적인 시나리오 조건에서 미래의 토지이용변화 양상을 살펴볼 필요가 있다. 이에 본 연구에서는 토지이용변화에 영향을 미치는 사회 경제적 요인과 과거의 토지이용변화 패턴을 고려하여 토지이용변화를 모델링 할 수 있는 CLUE(The Conversion of Land Use and its Effects) 모델을 이용하여 SRES(Special Report on Emissions Scenarios) 시나리오에 기초한 토지피복 변화를 살펴보고자 한다. 이는 향후 기후변화를 최소화하기위한 개발전략 수립에 있어서 정책방향을 결정하는 데 기초자료로 활용될 수 있을 것이다.

• Korean Journal of Remote Sensing
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• v.23 no.4
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• pp.297-309
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• 2007

The first Korean geostationary weather satellite, Communications, Oceanography and Meteorology Satellite (COMS) will be launched in 2008. The ground station for COMS needs to perform geometric correction to improve accuracy of satellite image data and to broadcast geometrically corrected images to users within 30 minutes after image acquisition. For such a requirement, we developed automated and fast geometric correction techniques. For this, we generated control points automatically by matching images against coastline data and by applying a robust estimation called RANSAC. We used GSHHS (Global Self-consistent Hierarchical High-resolution Shoreline) shoreline database to construct 211 landmark chips. We detected clouds within the images and applied matching to cloud-free sub images. When matching visible channels, we selected sub images located in day-time. We tested the algorithm with GOES-9 images. Control points were generated by matching channel 1 and channel 2 images of GOES against the 211 landmark chips. The RANSAC correctly removed outliers from being selected as control points. The accuracy of sensor models established using the automated control points were in the range of $1{\sim}2$ pixels. Geometric correction was performed and the performance was visually inspected by projecting coastline onto the geometrically corrected images. The total processing time for matching, RANSAC and geometric correction was around 4 minutes.

• Economic and Environmental Geology
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• v.52 no.2
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• pp.141-158
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• 2019

The quantity of heavy metals in agricultural surface and subsurface soils around coal-fired power plants located in Samcheonpo and Hadong, Gyeongnam Province, were determined. The analytical results for 48 and 61 soils in Samcheonpo and Hadong, respectively, showed that the concentrations of Cu, Hg, Ni, Pb, and Zn were below the warning criteria regulated by Korean Soil Conservation Act; however, Cd in 38 and 13 soils in Samcheonpo and Hadong, respectively, exceeded the criterion. As a result of calculation of the geoaccumulation index and the enrichment factor, the soils were extremely contaminated with Cd and such high loading of Cd to the soils was due to anthropogenic source(s). Sequential extraction of the soils, however, showed that heavy metals including Cd existed as hardly extractable phases, which represented a low bioavailability of the heavy metals. Our results indicated that Cd contamination around the coal-fired power plants was due to artificial source(s) and may unlikely deteriorate nearby ecosystems.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.10
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• pp.872-881
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• 2012

The Flight Model (FM) of a high-resolution electro-optical camera (EOS-C Ver.3.0), the mission payload of an Earth observation satellite, was successfully developed by Satrec Initiative. We designed it to give improved thermal representatives compared with the Structural-Thermal Model (STM) by optimizing the thermal characteristics based on the STM thermal vacuum test results. We developed the FM and verified the workmanship by performing the acceptance level thermal vacuum test. We also conducted the verification of its Thermal Mathematical Model (TMM) by the thermal balance test. As the result, it was confirmed that TMM faithfully represents the thermal characteristics of the EOS-C Ver.3.0 FM.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.1
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• pp.693-700
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• 2009

For real-time precise GPS data processing such as a long baseline network RTK (Real-Time Kinematic) survey, PPP (Precise Point Positioning) and monitoring of ionospheric/tropospheric delays, it is necessary to guarantee accuracy comparable to IGS (International GNSS Service) precise orbit with no latency. As a preliminary study for determining near real-time satellite orbits, the general procedures of satellite orbit determination, especially the dynamic approach, were studied. In addition, the transformation between terrestrial and inertial reference frames was tested to integrate acceleration. The IAU 1976/1980 precession/nutation model showed a consistency of 0.05 mas with IAU 2000A model. Since the IAU 2000A model has a large number of nutation components, it took more time to compute the transformation matrix. The classical method with IAU 2000A model was two times faster than the NRO (non-rotating origin) approach, while there is no practical difference between two transformation matrices.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.243-243
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• 2017

산업화에 따른 온실가스 배출량 증가는 심각한 기후변화의 원인으로 작용하여 우리나라를 포함한 전세계는 이에 대응하고자 노력하고 있다. 지구온난화 및 엘리뇨 현상 등으로 인하여 가뭄, 홍수, 한파, 혹서 등의 재해와 기상이변이 속출하고, 최근 들어서는 우리나라의 경우 매년 가뭄이 발생하고 있어 이에 대한 대책이 시급한 실정이다. IPCC 제5차 평가보고서에 의하면 최근 10년간 전세계 온실가스 배출량은 이전보다 급격이 증가하였고, 우리나라 온실가스 총배출량도 1990년대에 비해 약 100% 이상 증가하는 것으로 보고되었다. 또한, 농촌지역에서의 주요 기후변화 영향은 농업용수의 가용성과 적정 공급, 식량 안보, 농업 소득 등에 영향을 미치게 되며 농업이나 물, 산림, 생물 다양성 등을 위한 추가적인 적응 대책을 농촌지역의 발전을 위한 의사결정 차원의 정책으로 실행할 필요가 있다고 제언하고 있다. 미국, 영국, 일본 등 주요 선진국에서는 기후변화 관련 법적, 제도적 근거를 마련하여 자국의 기후변화 적응 프로그램을 이미 시행하고 있으며, 우리나라도 기후변화에 대비하기 위하여 체계적인 현실적인 적응 전략 도출을 위한 필요기술을 개발함으로서 농업용수 뿐만 아니라 수자원 관리 기술 및 시설물의 적응 역량을 강화하는 것이 절실한 실정이다. 농업분야에 있어서는 "농업 농촌 및 식품산업 기본법"의 제47조의2, 시행령 제19조의2 제1항, 시행규칙 제5조에 의하여 "기후변화가 농업에 미치는 영향과 기후변화에 따른 취약성 조사 평가"에 관한 기준을 제정하였다. 이러한 법적 근거를 바탕으로 농촌진흥청에서는 작물, 병해충, 가축 등을 대상으로 실태조사를 실시하고 있으며, 기후변화 영향 및 취약성 평가 결과보고서를 5년마다 제출하도록 고시하였다. 농업생산기반시설물 역시 기후변화에 따른 취약성을 평가하고 이를 위한 실태조사를 실시하도록 법적 근거가 마련되었는 바, 본 연구에서는 농업용 저수지의 재해 취약성 평가지표를 개발하고, 기후변화 시나리오에 의한 미래 농업용수 수문량을 산정하여 농업용 저수지의 재해 취약성 변화를 분석하고자 한다.

• Journal of Astronomy and Space Sciences
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• v.23 no.4
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• pp.337-344
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• 2006

KVN simulation, which is focused on evaluating the impacts of KVN to geodetic VLBI network, was performed. The KVN is under construction with three radio telescopes VLBI system for radio astronomy and space geodesy. To distinguish the impacts of KVN on global and local scale networks, we designed two different sizes of VLBI networks, namely, KVN-Asia and KVN-Pacific. While the former consisted of Far East Asia region VLBI stations, the latter consisted of pacific region VLBT stations. The primary purpose of our simulation is quantitative evaluation of KVN impacts before and after the participation of KVN in the previous two virtual networks. We selected two different sets of parameters to be estimated in the simulation as indices of evaluating estimation precision: station coordinates and EOPs. The station coordinates are evaluating index for KVN-Asia and the EOPs are another evaluating index for KVN-Pacific. From the simulation results of comparisons between evaluating indexes, 50% and 20% of maximum improvements for KVN-Asia and KVN-Pacific were anticipated respectively. We expect that the space geodetic use of KVN will be focused on the several promising research fields which are proposed through the simulation results.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.2
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• pp.147-161
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• 2020

In order to help elementary students understand the astronomical unit in depth, this study applied backward design 2.0 to check the effect on students' science academic achievement, performance evaluation, and science class satisfaction. As a result of the study, there was no statistically significant difference in the science achievement test, but the average score of the experimental group has improved. As a result of the performance evaluation test, there was a statistically significant difference because the feedback was well provided through the process-focused assessment and it helped in-depth understanding. As a result of the science class satisfaction test, there was a statistically significant difference in the areas of science curriculum and peer relation except for the science teacher area. This is because a differentiated science curriculum was designed through analysis of achievement standards, and various teaching methods of student-centered were implemented to reach achievement standards. We hope this study will focus on the impact of backward design 2.0 on learners in elementary science classes and help find ways to effectively apply backward design 2.0 in the field.