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Virtual City System Based on 3D-Web GIS for U-City Construction (U-City 구현을 위한 3D-Web GIS 기반의 가상도시 시스템)

  • Jo, Byung-Wan;Lee, Yun-Sung;Yoon, Kwang-Won;Park, Jung-Hun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.5
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    • pp.389-395
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    • 2012
  • U-City has been promoted nation-wide by development of recent IT technology. This paper studied the concept of 3D-virtual city in order to realize the current Ubiquitous City(U-City) efficiently, and to manage all the RFID/USN monitoring data in the real U-City. 3D-Virtual City is the concept of the reproduction of real world U-City, for embodying Ubiquitous technology while using Digital map, satellite image, VRML(Virtual Reality Modeling Language). U&V-City is the four-dimensional future city that real-time wire/wireless communication network and 3D-web GIS shall be connected that massive database, intelligent service be perceived through employing EAI(External Authoring Interface) that provides HTML&JAVA, and interface for efficient removal/process of massive information/ service and also by employing GPS/LBS/Navigation in support of world-wide orientation concept, and RTLS(Real Time Location System).

A case of congenital neurocutaneous melanosis (선천성 신경피부멜라닌증 1례)

  • Ha, Sang Kyun;Lee, Jae Myoung;Kim, Eun Ryoung;Hwang, Ho;Lee, Hong Tak
    • Clinical and Experimental Pediatrics
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    • v.49 no.2
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    • pp.212-216
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    • 2006
  • Neurocutaneous melanosis is a rare congenital syndrome characterized by the presence of large or multiple congenital melanocytic nevi and benign pigment cell tumors of the leptomeninges. Neurocutaneous melanosis is thought to represent an error in the morphogenesis of embryonal neuroectoderm. We experienced a neonate who presented with giant, dark colored pigmented nevi covering chest, abdomen, neck and arms, with satellite lesions. Magnetic resonance image showed a nodular hyperintense lesion in the amygdala of the right temporal lobe, and T1-weighted images showed hyperintensities in the adjacent leptomeninges. We report a rare case of neurocutaneous melanosis with a brief review of related literature.

Development of Agricultural Drought Assessment Approach Using SMAP Soil Moisture Footprints (SMAP 토양수분 이미지를 이용한 농업가뭄 평가 기법 개발)

  • Shin, Yongchul;Lee, Taehwa;Kim, Sangwoo;Lee, Hyun-Woo;Choi, Kyung-Sook;Kim, Jonggun;Lee, Giha
    • Journal of The Korean Society of Agricultural Engineers
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    • v.59 no.1
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    • pp.57-70
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    • 2017
  • In this study, we evaluated daily root zone soil moisture dynamics and agricultural drought using a near-surface soil moisture data assimilation scheme with Soil Moisture Active & Passive (SMAP, $3km{\times}3km$) soil moisture footprints under different hydro-climate conditions. Satellite-based LANDSAT and MODIS image footprints were converted to spatially-distributed soil moisture estimates based on the regression model, and the converted soil moisture distributions were used for assessing uncertainties and applicability of SMAP data at fields. In order to overcome drawbacks of the discontinuity of SMAP data at the spatio-temporal scales, the data assimilation was applied to SMAP for estimating daily soil moisture dynamics at the spatial domain. Then, daily soil moisture values were used to estimate weekly agricultural drought based on the Soil Moisture Deficit Index (SMDI). The Yongdam-dam and Soyan river-dam watersheds were selected for validating our proposed approach. As a results, the MODIS/SMAP soil moisture values were relatively overestimated compared to those of the TDR-based measurements and LANDSAT data. When we applied the data assimilation scheme to SMAP, uncertainties were highly reduced compared to the TDR measurements. The estimated daily root zone soil moisture dynamics and agricultural drought from SMAP showed the variability at the sptio-temporal scales indicating that soil moisture values are influenced by not only the precipitation, but also the land surface characteristics. These findings can be useful for establishing efficient water management plans in hydrology and agricultural drought.

Auto-detection of Halo CME Parameters as the Initial Condition of Solar Wind Propagation

  • Choi, Kyu-Cheol;Park, Mi-Young;Kim, Jae-Hun
    • Journal of Astronomy and Space Sciences
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    • v.34 no.4
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    • pp.315-330
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    • 2017
  • Halo coronal mass ejections (CMEs) originating from solar activities give rise to geomagnetic storms when they reach the Earth. Variations in the geomagnetic field during a geomagnetic storm can damage satellites, communication systems, electrical power grids, and power systems, and induce currents. Therefore, automated techniques for detecting and analyzing halo CMEs have been eliciting increasing attention for the monitoring and prediction of the space weather environment. In this study, we developed an algorithm to sense and detect halo CMEs using large angle and spectrometric coronagraph (LASCO) C3 coronagraph images from the solar and heliospheric observatory (SOHO) satellite. In addition, we developed an image processing technique to derive the morphological and dynamical characteristics of halo CMEs, namely, the source location, width, actual CME speed, and arrival time at a 21.5 solar radius. The proposed halo CME automatic analysis model was validated using a model of the past three halo CME events. As a result, a solar event that occurred at 03:38 UT on Mar. 23, 2014 was predicted to arrive at Earth at 23:00 UT on Mar. 25, whereas the actual arrival time was at 04:30 UT on Mar. 26, which is a difference of 5 hr and 30 min. In addition, a solar event that occurred at 12:55 UT on Apr. 18, 2014 was estimated to arrive at Earth at 16:00 UT on Apr. 20, which is 4 hr ahead of the actual arrival time of 20:00 UT on the same day. However, the estimation error was reduced significantly compared to the ENLIL model. As a further study, the model will be applied to many more events for validation and testing, and after such tests are completed, on-line service will be provided at the Korean Space Weather Center to detect halo CMEs and derive the model parameters.

A Study on the Map Accuracy Assessment of Positioning Data Using Statistical Approach Analysis (오차분석을 이용한 지도 위치정확도 평가기법에 관한 연구)

  • Cho, Bong-Whan;Lee, Yong-Woong;Choi, Sun-Yong
    • Journal of Korean Society for Geospatial Information Science
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    • v.5 no.1 s.9
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    • pp.71-80
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    • 1997
  • This paper suggests a Map Accuracy Standards by analyzing U.S. National Map Accuracy Standards, by considering korean terrain feature and statistical error theory for paper and digital maps on the scale of 1:50,000. Map accuracy standards require horizontal accuracy to be reported as a circular error with 90% confidence level through Linear Error Probable(LEP) theory and Circular Error Probable(CEP) theory. In order to verify the proposed methodology for positioning accuracy testing, several kinds of test point were selected and tested. These test points were extracted at the centers of roads and bridges, the comers of the independent building, the edges of geographical botany, and the tops of mountains. The positioning accuracy assessment was peformed by comparing the positions of test points in digital maps generated three different sources with those acquired by high accurate GPS surveying. The digital maps were produced from aerial photographs and SPOT satellite image using analytical plotter and 1:50,000 paper map.

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Extraction of the aquaculture farms information from the Landsat- TM imagery of the Younggwang coastal area

  • Shanmugam, P.;Ahn, Yu-Hwan;Yoo, Hong-Ryong
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2004.03a
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    • pp.493-498
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    • 2004
  • The objective of the present study is to compare various conventional and recently evolved satellite image-processing techniques and to ascertain the best possible technique that can identify and position of aquaculture farms accurately in and around the Younggwang coastal area. Several conventional techniques performed to extract such information fiom the Landsat-TM imagery do not seem to yield better information about the aquaculture farms, and lead to misclassification. The large errors between the actual and extracted aquaculture farm information are due to existence of spectral confusion and inadequate spatial resolution of the sensor. This leads to possible occurrence of mixture pixels or 'mixels' of the source of errors in the classification techniques. Understanding the confusing and mixture pixel problems requires the development of efficient methods that can enable more reliable extraction of aquaculture farm information. Thus, the more recently evolved methods such as the step-by-step partial spectral end-member extraction and linear spectral unmixing methods are introduced. The farmer one assumes that an end-member, which is often referred to as 'spectrally pure signature' of a target feature, does not appear to be a spectrally pure form, but always mix with the other features at certain proportions. The assumption of the linear spectral unmxing is that the measured reflectance of a pixel is the linear sum of the reflectance of the mixture components that make up that pixel. The classification accuracy of the step-by-step partial end-member extraction improved significantly compared to that obtained from the traditional supervised classifiers. However, this method did not distinguish the aquaculture ponds and non-aquaculture ponds within the region of the aquaculture farming areas. In contrast, the linear spectral unmixing model produced a set of fraction images for the aquaculture, water and soil. Of these, the aquaculture fraction yields good estimates about the proportion of the aquaculture farm in each pixel. The acquired proportion was compared with the values of NDVI and both are positively correlated (R$^2$ =0.91), indicating the reliability of the sub-pixel classification.ixel classification.

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Landform and Environment in Border Region of N. Korea and China (북중 접경 지역의 지형과 환경)

  • Lee, Min-Boo;Kim, Nam-Shin;Cho, Yong-Chan;Cha, Jin-Yeol
    • Journal of the Korean Geographical Society
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    • v.51 no.6
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    • pp.761-777
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    • 2016
  • This study is to suggest landform and environmental problems of border region of N. Korea and China by analyzing results of field work for the Dumangang and the Amnokgang from year 2000 up to year 2016. By the social system in North korea, access of study material is possible with satellite image and published statistical data, but impossible direct data collection. We gathered field work data on landform and environment in border Region of N. Korea and China. Before field survey, we analysed geometrical landform and geology using DEM and digital geology map. We analyzed landform and environmental problems occurring in upper, midstream, and downstream region of the Dumangang and the Amnokgang using field work data. Resultingly, this study will be expected to support as basic data for resonable management on natural resources and empirical research activities on North Korea.

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A Study on improvement of sounding density of ENCs (전자해도 수심 밀집도 개선에 관한 연구)

  • Oh, Se-Woong;Park, Jong-Min;Suh, Sang-Hyun;Lee, Moon-Jin;Jeon, Tae-Byung
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2011.06a
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    • pp.34-36
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    • 2011
  • ENCs is edited based on the numerical charts for publishing paper charts and serviced in forms of grid styles. For this reason, the density of sounding information of ENCs is not consistent and was required for improvement. In this study, K-Means, ISODATA clustering algorithm as classification methods for satellite image was reviewed and adopted to case study. The developed results include loading module of ENC data, improvement algorithm of sounding information, writing module of ENC data. According to the results of algorithm, we could confirm the improved result.

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The Characteristics of Land Use Change at the Urban Fringe - The Case of Daegu Metropolitan City - (대도시 주변 신개발지의 개발특성에 관한 연구 - 대구광역시를 사례지역으로 -)

  • Park, Sun-Hyung;Kim, Jae-Ik
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.2
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    • pp.36-46
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    • 2007
  • The primary purpose of this study is to identify the characteristics of land use change at the urban fringe. For this purpose, the Daegu Metropolitan City is selected as a study area. Land use changes between 1990 and 2000 in fringe areas are identified by processing Landsat TM5 imageries. The main findings are follows: First, land development has been driven by residential development, especially large-scale residential development encouraged by the two-million housing construction plan. Second, the type and size of the land use conversion are not identical across the study area. For example, the main land use type of the newly developed area of Buk-gu is residential use while that of Suseong-gu is public use. Third, most of residential development type is a high-density development which is quite different from American type of low-density development.

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The Slewing Mirror Telescope of the Ultra Fast Flash Observatory Pathfinder

  • Jeong, Soomin;Choi, Ji Nyeong;Jung, Aera;Kim, Min Bin;Kim, Sug-Whan;Kim, Ye Won;Kim, Jieun;Lee, Jik;Lim, Heuijin;Na, Go Woon;Nam, Jiwoo;Park, Il Hung;Ripa, Jakub.;Suh, Jung Eun
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.208.2-208.2
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    • 2012
  • The Slewing Mirror Telescope (SMT) is a key telescope of Ultra-Fast Flash Observatory (UFFO) space project to explore the first sub-minute or sub-seconds early photons from the Gamma Ray Bursts (GRBs) afterglows. The first realization of UFFO is the 20kg UFFO-Pathfinder (UFFO-P) to be launched on board the Russian Lomonosov satellite in 2013 by the Soyuz-2 rocket. Once the UFFO Burst Alert & Trigger Telescope (UBAT) detects the GRBs, Slewing mirror (SM) will rotate to bring the GRB into the SMT's field of view instead of slewing the entire spacecraft. SMT can image the UV/Optical counterpart with about 4-arcsec accuracy. However it will provide a important understanding of the GRB mechanism by measuring the sub-minute optical photons from GRBs. SMT can respond to the trigger over $35^{\circ}{\times}35^{\circ}$ wide field of view within 1 sec by using Slewing Mirror Stage (SMS). SMT has 10-cm Ritchey-Chretien telescope and $256{\times}256$ pixilated Intensified Charge-Coupled Device (ICCD) on focal plane. In this paper, we discuss the overall design of UFFO-P SMT instrument and payloads development status.

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