• Title/Summary/Keyword: Terrain analysis

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Three-Dimensional GSIS for Determination of Optimal Route (3차원 GSIS를 이용한 최적노선 선정)

  • Kang, In-Joon;Choi, Hyun;Park, Hun-Shik
    • Journal of Korean Society for Geospatial Information Science
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    • v.11 no.1 s.24
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    • pp.71-75
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    • 2003
  • The highway is greatly changed by the constant economic growth for a long times the traffic situation such as the large volumes and the performance vehicles, the performance enlargement of vehicles, the high speedization, etc., due to growth economic. A study of an optimal route selection model is researched over late 1980s by development of computer and GSIS, and consisted including research about the optimal route that uses digital terrain model in domestic such as the earth volume calculations, the mass curve output and the automation system construction. Lately, the study of the driving simulation of the highway and the virtual reality using VGIS(Virtual Geographic Information System) is researched. This study shows when the alternative highway selection considered surrounding facilities, development plan and according to estimate amount of traffic and the additional possibility of view analysis and environment effect analysis element will study through 3D simulation method.

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Accuracy Analysis on Geodetic Network in Jeju area using GPS (GPS에 의한 제주지역의 측지기준망 정확도 분석)

  • Kang, Sang-Gu;Jung, Young-Dong;Yang, Young-Bo
    • Journal of Korean Society for Geospatial Information Science
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    • v.14 no.1 s.35
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    • pp.65-74
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    • 2006
  • A rapidly developed satellite technology is used in comprehensive fields such as spatial data aquisition and applications. Especially a GPS positioning is expected to reinvigorate at the national reference system changes to ITRF(International Terrain Reference Frame). Currently the National Geographic Information Institute(NGII) issues a triangulation point coordinate by separating old and new coordinates and in the year of 2007 it will be scheduled to be changed ITRF. The triangulation point coordinate in Cheju area causes some problems due to the difference original observation and re-observation. Thus in this study a GPS observation is conducted after re-organizing geodetic network based on 1st and 2nd order triangulation in order to check the current triangulation points in Cheju area. After the GPS observation data analysis, stable points were extracted, proposed a geodetic network and its application.

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3D Simulation of Thin Film using Contour Analysis of Interference Fringe Image and Interpolation Method (간섭무늬 영상 등고선 해석과 보간법을 이용한 박막의 삼차원 정보 형상화)

  • Kim, Jin-Hyoung;Ko, Yun-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.49 no.2
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    • pp.8-17
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    • 2012
  • In this paper we proposes a new framework to obtain 3D shape information of thin film rapidly. The conventional equipments based on reflectometry are not suitable for obtaining 3D overall shape information of thin film rapidly since they require more than 30 minutes to measure the absolute thickness for 170 points. The proposed framework is based on an image analysis method that extracts contour lines from interference fringes images using Canny edge detector. The absolute thickness for contour lines are measured and then a height map from the contour lines is obtained by interpolation using Borgefors distance transformation. The extracted height map is visualized using the DirectX 3D terrain rendering method. The proposed framework can provide 3D overall shape information of thin film in about 5 minutes since relatively small number of real measurement for contour lines is required.

Analysis of the Adjacent Channel Interference from High Power Gap-filler in Satellite Digital Multimedia Broadcasting (DMB) (위성 DMB에서 지상중계기 출력에 의한 인접 채널 간섭 분석)

  • Choi, Bokun;Lee, Youngjin;Hong, Youngjin;Seo, JongSoo
    • Journal of Broadcast Engineering
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    • v.10 no.3
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    • pp.372-382
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    • 2005
  • DS/CDM-QPSK (ITU-R Recommendation BO.1130-4 Annex 6, 'Digital System E'), which has been adoptedas a standard of Korean Satellite DMB (Digital Multimedia Broadcasting) system, is a satellite-based multimedia broadcasting service which transmits the multi-channel and high quality contents to the terrestrial users through a satellite or gap-fillers. The broadcast from a satellite is directly received in the plain terrain which are within line-of-sight, but in cities where the broadcast cannot be received directly due to the shadow of buildings, an attempt is being made to install 'Gap-Fillers' to improve the reception in those areas. The gap-fillers, however, may induce interference to service of adjacent band, when their output power is substantially higher compared to the received signal power of signal from a satellite of the adjacent service. In this paper, a link budget analysis is performed, and the optimal EIRP of a gap-filler to maximize the gap-filler coverage, while preventing adjacent band interference is derived.

A Study on Sustainable Outdoor Space of Regional Public Hospitals (지역거점공공병원의 지속가능한 외부공간에 대한 연구)

  • Yoon, Eunji;Lim, Yeonghwan
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.23 no.4
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    • pp.17-25
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    • 2017
  • Purpose: Since hospitals have a big impact on the natural and social environment, hospitals' sustainability must be considered in various aspects including environmental, social, and economical aspects. So far, research on sustainable hospitals has mainly been conducted on indoor environment, but outdoor space of hospital is as important as well. The purpose of this research is to study the sustainability of hospital outdoor space and to make proposals for improving sustainable regional public hospitals. Methods: Through preceding research analysis and literature review, the concept of sustainable outdoor space of hospital was defined. Also, the evaluation contents of outdoor space were extracted from domestic and foreign green building certification criteria. With this analytic frame, we visited 4 regional public hospitals in Korea, interviewed the facility managers, and analyzed sustainability of hospital outdoor space. Results: Analysis of 4 regional public hospitals reveals that there is a lack of consideration for sustainability in all 4 categories; urban and network, natural environment, community, and user. In terms of community, sustainability has rarely been applied to all four hospitals. The site selection and terrain of the site were essential to sustainability. Implications: Establishing a master plan considering future expansion is critical. Also more attempt to show regional characteristics is needed. It is necessary to design a comprehensive outdoor space that considers sustainability and also healing environment. Level difference in the site can be used as a design element.

DOES LACK OF TOPOGRAPHIC MAPS LIMIT GEO-SPATIAL HYDROLOGY ANALYSYS?

  • Gangodagamage, Chandana;Flugel, Wolfgang;Turrel, Dr.Hagh
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.82-84
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    • 2003
  • Watershed boundaries and flow paths within the watershed are the most important factors required in watershed analysis. Most often the derivation of watershed boundaries and stream network and flow paths is based on topographical maps but spatial variation of flow direction is not clearly understandable using this method. Water resources projects currently use 1: 50, 000-scale ground survey or aerial photography-based topographical maps to derive watershed boundary and stream network. In basins, where these maps are not available or not accessible it creates a real barrier to watershed geo-spatial analysis. Such situations require the use of global datasets, like GTOPO30. Global data sets like ETOPO5, GTOPO30 are the only data sets, which can be used to derive basin boundaries and stream network and other terrain variations like slope aspects and flow direction and flow accumulation of the watershed in the absence of topographic maps. Approximately 1-km grid-based GTOPO 30 data sets can derive better outputs for larger basins, but they fail in flat areas like the Karkheh basin in Iran and the Amudarya in Uzbekistan. A new window in geo-spatial hydrology has opened after the launching of the space-borne satellite stereo pair of the Terra ASTER sensor. ASTER data sets are available at very low cost for most areas of the world and global coverage is expected within the next four years. The DEM generated from ASTER data has a reasonably good accuracy, which can be used effectively for hydrology application, even in small basins. This paper demonstrates the use of stereo pairs in the generation of ASTER DEMs, the application of ASTER DEM for watershed boundary delineation, sub-watershed delineation and explores the possibility of understanding the drainage flow paths in irrigation command areas. All the ASTER derived products were compared with GTOPO and 1:50,000-based topographic map products and this comparison showed that ASTER stereo pairs can derive very good data sets for all the basins with good spatial variation, which are equal in quality to 1:50,000 scale maps-based products.

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Spectral Signatures of Tombs and their Classification (묘지의 분광적 특성과 통계적 분류)

  • Eunmi Change;Kyeong Park;Minho Kim
    • Journal of the Korean Geographical Society
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    • v.39 no.2
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    • pp.283-296
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    • 2004
  • More than 0.5 percent of land in Korea is used for cemetery and the rate is growing in spite of the increase in cremation these days. The systematic management of tombs may be possible through the ‘Feature Extraction’ method which is applied to the high-resolution satellite imagery. For this reason, this research focused on finding out the radiometric characteristics of tombs and the classification of them. An IKONOS image of northwest areas of Seoul with 8km x 10km dimension was analyzed. After sampling 24 tombs in the study area, the statistical radiometric characteristics of tombs are analyzed. And tombs were classified based on the criteria such as landscape, NDVI, and cluster analysis. In addition, it was investigated if the aspect or slope of the terrain influenced to the classification of tombs. As a result of this research, authors find that there is similarity between the classification tv NDVI and the classification through cluster analysis. And aspect or slope didn't have much influence on the classification of tombs.

Preprocessing Methods and Analysis of Grid Size for Watershed Extraction (유역경계 추출을 위한 DEM별 전처리 방법과 격자크기 분석)

  • Kim, Dong-Moon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.1
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    • pp.41-50
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    • 2008
  • Recent progress in state-of-the-art geospatial information technologies such as digital mapping, LiDAR(Light Detection And Ranging), and high-resolution satellite imagery provides various data sources fer Digital Elevation Model(DEM). DEMs are major source to extract elements of the hydrological terrain property that are necessary for efficient watershed management. Especially, watersheds extracted from DEM are important geospatial database to identify physical boundaries that are utilized in water resource management plan including water environmental survey, pollutant investigation, polluted/wasteload/pollution load allocation estimation, and water quality modeling. Most of the previous studies related with watershed extraction using DEM are mainly focused on the hydrological elements analysis and preprocessing without considering grid size of the DEMs. This study aims to analyze accuracy of the watersheds extracted from DEMs with various grid sizes generated by LiDAR data and digital map, and appropriate preprocessing methods.

Evaluation of Slope Stability of Taebaeksan National Park using Detailed Soil Map (정밀토양도를 이용한 태백산국립공원의 사면안정성 평가)

  • Kim, Young-Hwan;Jun, Byong-Hee;Jun, Kye-Won
    • Journal of Korean Society of Disaster and Security
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    • v.12 no.2
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    • pp.65-72
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    • 2019
  • More than 64% of Korea's land is occupied by mountain regions, which have terrain characteristics that make it vulnerable to mountain disasters. The trails of Taebaeksan Mountain National Park-the region considered in this study-are located in the vicinity of steep slopes, and therefore, the region is vulnerable to landslides and debris flow during heavy storms. In this study, a slope stability model, which is a deterministic analysis method, was used to examine the potential occurrence of landslides. According to the soil classification of the detailed soil map, the specific weight of soil, effective cohesion, internal friction angle of soil, effective soil depth, and ground slope were used as the parameters of the model, and slope stability was evaluated based on the DEM of a 1 m grid. The results of the slope stability analysis showed that the more hazardous the area was, the closer the ratio of groundwater/effective soil depth is to 1.0. Further, many of the private houses and commercial facilities in the lower part of the national park were shown to be exposed to danger.

Timing Jitter Analysis and Improvement Method using Single-Shot LiDAR system (Single-Shot LiDAR system을 이용한 Timing Jitter 분석 및 개선 방안)

  • Han, Mun-hyun;Choi, Gyu-dong;Song, Min-hyup;Seo, Hong-seok;Mheen, Bong-ki
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.10a
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    • pp.172-175
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    • 2016
  • Time of Flight(ToF) LiDAR(Light Detection And Ranging) technology has been used for distance measurement and object detection by measuring ToF time information. This technology has been evolved into higher precision measurement field such like autonomous driving car and terrain analysis since the retrieval of exact ToF time information is of prime importance. In this paper, as a accuracy indicator of the ToF time information, timing jitter was measured and analyzed through Single-Shot LiDAR system(SSLs) mainly consisting of 1.5um wavelength MOPA LASER, InGaAs Avalanche Photodiode(APD) at 31M free space environment. Additionally, we applied spline interpolation and multiple-shot averaging method on measured data through SSLs to improve ToF timing information.

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