• Title/Summary/Keyword: SAR analysis

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KOMPSAT Image Processing and Analysis (다목적실용위성 영상처리 및 분석)

  • Kwang-Jae Lee;Kwan-Young Oh;Sung-Ho Chae;Sun-Gu Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.6_3
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    • pp.1671-1678
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    • 2023
  • The Korea multi-purpose satellite (KOMPSAT) series consisting of multi-sensors has been used in various fields such as land, environmental monitoring, and disaster analysis since its first launch in 1999. Recently, as various information processing technologies (high-speed computing technology, computer vision, artificial intelligence, etc.) that are rapidly developing are utilized in the field of remote sensing, it has become possible to develop more various satellite image processing and analysis algorithms. In this special issue, we would like to introduce recently researched technologies related to the KOMPSAT image application and research topics participated in the 2023 Satellite Information Application Contest.

A Prediction Model of Distressed Craft Drift Using Fluid Dynamics Analysis (유체역학 이론에 근거한 조난물체의 위치 추정 모델)

  • 강신영
    • Journal of Korean Port Research
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    • v.14 no.3
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    • pp.353-360
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    • 2000
  • In this study a drift prediction model based on fluid dynamics theory is introduced. The essential effects of environmental loads and target characteristics are taken into account from a fluid dynamics point of view. The governing equations of motion are derived from Netwon's law of dynamics. In the mathematical formulation only three degrees of freedom(surge, sway, yaw) of the drifting object are assumed and the environmental loads considered are the forces and moments by wind and current. A computer algorithm for this model is implemented to obtain the numerical result in the time domain. The preliminary tests for model verification are conducted and the results are compared with the field experiment data as well as leeway formula suggested from the field test data.

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Plane Position Accuracy Analysis of Extracted Data from LiDAR (LiDAR 추출 자료의 평면위치 정확도 분석)

  • Yoon Hee-Cheon;Park Joung-Hyun;Lee Chang-Bok;Kang Joon-Mook
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.119-124
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    • 2006
  • The world which based on knowledge and information is changing significantly. In the various knowledge and information, the importance of GSIS has increased for efficient application and management of country. The Geomatics has made a change rapidly, observation methods have improved too. The existing acquisition of Geoinformation depend on aerial photogtaphs, but new technology Jike application of high resolution satellite images. SAR and LiDAR, is the fastest. especially, LiDAR surveying is most advanced active observation technology and Geoinfomtation is acquired by reflection of its laser pulse. In this study. the position accuracy of extracted building from LiDAR was evaluated by GPS surveying, then each data was made comparison between LiDAR's and GPS's data. After processing. the result of this study will be suggested basic data about application.

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A Prediction Model of Distressed Craft Drift Using Fluid Dynamics Analysis (유체역학 이론에 근거한 조난물체의 위치 추정 모델)

  • 강신영
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2000.11a
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    • pp.63-71
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    • 2000
  • In this study a drift prediction model based on fluid dynamics theory is introduced. The essential effects of environmental loads and target characteristics are taken into account from a fluid dynamics point of view. The governing equations of motion are derived from Newton's law of dynamics. In the mathematical formulation only three degrees of freedom(surge, sway, yaw) of the drifting object are assumed and the environmental loads considered are the forces and moments by wind and current. A computer algorithm for this model is implemented to obtain the numerical result in the time domain. The preliminary tests for model verification are conducted and the results are compared with the field experiment data as well as leeway formula suggested from the field test data.

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Design, Synthesis and Evaluation of Pentacyclic Triterpenoids Similar to Glycyrrhetinic Acid Via Combination of Chemical and Microbial Modification as Glycogen Phosphorylases Inhibitor

  • Zhu, Yuyao;Zhang, Jian;Huang, Xiaode;Chen, Bin;Qian, Hua;Zhao, Botao
    • Journal of Microbiology and Biotechnology
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    • v.28 no.11
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    • pp.1876-1882
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    • 2018
  • A series of pentacyclic triterpenoids similar to glycyrrhetinic acid were designed and synthesized via the combination of chemical modification and microbial catalysis. All products were screened for the glycogen phosphorylases inhibitory activities in vitro. Within this series of derivatives, compound 5 displayed good inhibitory activities with $IC_{50}$ value of $27.7{\mu}M$, which is better than that of the other derivatives and glycyrrhetinic acid. Structure-activity relationship (SAR) analysis of these inhibitors was also discussed.

Analysis of Criteria Regarding Frontal and Side Impacts of Wheelchair Occupant in Vehicle by Computer Simulation Method (컴퓨터 시뮬레이션 방법을 이용한 휠체어 탑재 차량의 전방/측방충돌 시 휠체어 탑승자의 위험도 분석)

  • Kim, S.M.;Lee, M.P.;Park, S.Y.
    • Journal of Biomedical Engineering Research
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    • v.27 no.6
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    • pp.365-369
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    • 2006
  • According to the IIHS (Insurance Institute fur Highway Safety), side impacts are made up 30% of all accidents (reported 1998). In the case of auto accidents, head and neck injuries were most common as 58%, injuries to the body's trunk equaled 32%, and injuries to the abdomen were 21%. Therefore in this study, injury of wheelchair occupant in frontal and side impact of wheelchair loaded vehicle was analyzed using computer simulation method. The occupant was restrained at the rear of wheelchair by the lap belt. The detailed fixation and restrain conditions of the wheelchair occupant are referred to SAR J2249's recommendation. We estimated HIC(Head Injury Criteria) and HNIC (Head and Neck Injury Criteria) based on measured data.

Children's Mobile Phone Use and Dosimetry

  • Lee, Ae-Kyoung;Kwon, Jong-Hwa
    • Journal of electromagnetic engineering and science
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    • v.15 no.3
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    • pp.167-172
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    • 2015
  • Research results on possible effects caused by radiofrequency fields in children are limited because most of the studies published so far have focused on adults, rather than children. Mobile phone use is now widespread, even among younger children. If a biological risk due to mobile phone exposure is found, it might be greater in children because their bodies might be more sensitive to radiofrequency energy. The issue of a possible difference in sensitivity between adults and children begins with whether any difference exists physically in terms of electromagnetic absorption. This paper presents a review of recent publications on dosimetric comparisons between children and adults with respect to radiation from mobile phones. The issue of the health effects of mobile phone use is beyond the scope of the present review. Most of the dosimetry research on possible differences in power absorption between children and adults has been based on numerical modeling and analysis. The understanding of the results so far is presented and needed studies are described.

ANALYSIS ON RECEIVING PERFORMANCE FOR KOMPSAT-5 X-BAND IMAGE DATA

  • Park, Durk-Jong;Kang, Chi-Ho;Ahn, Sang-II
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.208-211
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    • 2008
  • Band-limited filtering will be applied to remove interference resulted from two neighbored channels in the transmission of KOMPSAT-5 X-Band image data. In that case, receiver in ground station should prepare righteous matched filter to avoid huge BER degradation depending on the matched filter of COTS receiver. As an effort to simulate the bandlimited filtering, test filter was designed and manufactured on the basis of main specification for output filter of KOMPSAT-5 satellite. Consequently, 1.8dB of BER degradation was measured at the output of test band-pass filter, but the degradation was downsized up to 0.4dB thanks to the adaptive matched filter of COTS receiver.

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Evaluation of ALOS PALSAR Interferometry in the West Coast of Korea;Preliminary Results

  • Choi, Jung-Hyun;Lee, Chang-Wook;Won, Joong-Sun
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.25-28
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    • 2007
  • Precise digital elevation model (DEM) is an important issue in coastal area where DEMs in a time series are especially required. Although LIDAR system is useful in coastal regions, it is not yet popular in Korea mainly because of its high surveying cost and national security reasons. Recently, precise coastal DEM have been made using radar interferometry, waterline method. One of these methods, Spaceborne imaging radar interferometry has been widely used to measure the topography and deformation of the Earth. We acquired ALOS PALSAR FBD mode (Fine Beam Dual) data for evaluating the quality of interferograms and their coherency. The purpose of this study is construction of DEM using the ALOS PALSAR data using radar interferometry and analysis of surface characteristics by coherence and magnitude map over the Ganghwado and Siwha tidal flats and near coastal lands.

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Geospatial Technologies for Landslide Inventory: Application and Analysis to Earthquake-Triggered Landslide of Sindhupalchowk, Nepal

  • Acharya, Tri Dev;Yang, In Tae;Lee, Dong Ha
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.2
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    • pp.95-106
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    • 2016
  • Landslide is one of the natural hazards, triggered by rainfall or earthquake and it leads to damage and loss of properties and lives especially in hilly and mountainous regions. Inventory maps of the area is of much importance in order to understand the landslide phenomena in detail, conduct further studies on landslide, prepare susceptibility map and minimize risk. Inventory maps of landslides can be constructed by several methods, using multiple images through visual interpretation, using algorithms in multi-spectral or SAR images or verification from field investigation. The possible methods were explored for Sindhupalchowk district of Nepal, which was struck by massive earthquake on 2015 and landslide inventory was prepared. The inventory was analyzed for its frequency over elevation, slope aspect and dominant soil classes and also the information value for their occurrence probability.