• Title/Summary/Keyword: 지형극복

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A study on the estimation of rock mass classes using the information off a tunnel center line (터널 중심선으로부터 이격된 자료를 활용한 미시추구간의 암반등급 산정에 관한 연구)

  • You, Kwang-Ho;Lee, Sang-Ho;Choo, Suk-Yeon;Jue, Kwang-Sue
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.6 no.2
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    • pp.101-111
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    • 2004
  • In order to guarantee the stability of a tunnel and its optimum design, it is very important to obtain enough ground investigation data. In realty, however, it is not the case due to the limitation of measuring spatially distributed data and economical reasons. Especially, there are regions where drilling is impossible due to civil appeal and mountainous topology, and it is also difficult to estimate rock mass classes quantitatively with only geophysical exploration data. In this study, therefore, 3 dimensional multiple indicator kriging (3D-MI kriging), which can incorporate geophysical exploration data and drill core data off a tunnel center line, is proposed to cope with such problems. To this end, two dimensional mutiple indicator kriging, which is one of the geostatistical techniques, is extended for three dimensional analysis. Also, the proposed 3D-MI kriging was applied to determine the rock mass classes by RMR system for the design of a Kyungbu express rail way tunnel.

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Automatic Extraction of Individual Tree Height in Mountainous Forest Using Airborne Lidar Data (항공 Lidar 데이터를 이용한 산림지역의 개체목 자동 인식 및 수고 추출)

  • Woo, Choong-Shik;Yoon, Jong-Suk;Shin, Jung-Il;Lee, Kyu-Sung
    • Journal of Korean Society of Forest Science
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    • v.96 no.3
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    • pp.251-258
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    • 2007
  • Airborne Lidar (light detection and ranging) can be an effective alternative in forest inventory to overcome the limitations of conventional field survey and aerial photo interpretation. In this study, we attempt to develop methodologies to identify individual trees and to estimate tree height from airborne Lidar data. Initially, digital elevation model (DEM) data representing the exact ground surface were generated by removing non-ground returns from the multiple-return laser point clouds, obtained over the coniferous forest site of rugged terrain. Based on the canopy height model (CHM) data representing non-ground layer, individual tree heights are extracted through pseudo-grid method and moving window filtering algorithm. Comparing with field survey data and aerial photo interpretation on sample plots, the number of trees extracted from Lidar data show over 90% accuracy and tree heights were underestimated within 1.1m in average at two plantation stands of pine (Pinus koraiensis) and larch (Larix leptolepis).

Correction of Radiometric Distortion Caused by Geometric Property in SAR image using SAR Simulation (SAR영상의 모의제작에 의한 기하학적 복사왜곡의 보정)

  • Jeong, Soo;Yeu, Bock-Mo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.16 no.1
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    • pp.1-7
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    • 1998
  • SAR data can be achieved independently of weather conditions or sun illumination which is main limitation of electro-optical sensor to get image. The information from imagery can be more enlarged using Shh data be-cause SAR data offers different information from electro-optical sensor. SAR data contains various distortions caused by the radar specification and geometric properties of data acquisition. These distortions should be removed to get the information with acceptable accuracy. In this study, we aimed to correct the radiometric distortion in Shh image caused by the geometric property of the object. For this purpose, we simulated the SAR image by modelling of the power of return beam which is variable according to the geometric configuration between SAR antenna and ground object. Dividing the SAR image by the simulation image, then, we can get the radiometrically corrected image. As a result of this study, we could minimize the effect of radiometric distortion in achieving some qualitative information from SAR image for the related field, such as Geospatial Information System.

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Analysis of Image Integration Methods for Applying of Multiresolution Satellite Images (다중 위성영상 활용을 위한 영상 통합 기법 분석)

  • Lee Jee Kee;Han Dong Seok
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.22 no.4
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    • pp.359-365
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    • 2004
  • Data integration techniques are becoming increasing1y important for conquering a limitation with a single data. Image fusion which improves the spatial and spectral resolution from a set of images with difffrent spatial and spectral resolutions, and image registration which matches two images so that corresponding coordinate points in the two images correspond to the same physical region of the scene being imaged have been researched. In this paper, we compared with six image fusion methods(Brovey, IHS, PCA, HPF, CN, and MWD) with panchromatic and multispectral images of IKONOS and developed the registration method for applying to SPOT-5 satellite image and RADARSAT SAR satellite image. As the result of tests on image fusion and image registration, we could find that MWD and HPF methods showed the good result in term of visual comparison analysis and statistical analysis. And we could extract patches which depict detailed topographic information from SPOT-5 and RADARSAT and obtain encouraging results in image registration.

Study on Automated Error Detection Method for Enhancing High Definition Map (정밀도로지도 레이어의 품질향상을 위한 자동오류 판독 연구)

  • Hong, Song Pyo;Oh, Jong Min;Song, Yong Hyun;Shin, Young Min;Sung, Dong Ki
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.4
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    • pp.391-399
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    • 2020
  • Autonomous driving can be limited by only using sensors if the sensor is blocked by sudden changes in surrounding environments or large features such as heavy vehicles. In order to overcome the limitations, the precise road-map has been used additionally. In korea, the NGII (National Geographic Information Institute) produces and supplies high definition map for autonomous vehicles. Accordingly, in this study, errors occurring in the process of e data editing and dtructured esditing of high definition map are systematically typed providing by the National Geographic Information Institute. In addition, by presenting the error search process and solution for each situation, we conducted a study to quickly correct errors in high definition map, and largely classify the error items for shape integrity, spatial relationship, and reference relationship, and examine them in detail. The method was derived.

A Study on the Fusion of DEM Generated from Images of Optical Satellite and SAR (광학 위성영상과 SAR 위성영상의 DEM 융합에 관한 연구)

  • Yeu, Bock-Mo;Hong, Jae-Min;Jin, Kyeong-Hyeok;Yoon, Chang-Rak
    • 한국지형공간정보학회:학술대회논문집
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    • 2002.11a
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    • pp.58-65
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    • 2002
  • The most widespread techniques for DEM generation are stereoscopy for optical sensor images and interfereometry for SAR images. These techniques suffer from certain sensor and processing limitations, which can be overcome by the synergetic use of both sensors and DEMs respectively. In this paper, different strategies for fusing SAR and optical data are combined to derive high quality DEM products. The multiresolution wavelet transform, which take advantage of the complementary properties of SAR and stereo optical DEMs, will be applied for the fusion process. By taking advantage of the fact that errors of the DEMs are of different nature using the multiresolution wavelet transform, affected part are filtered and replaced by those of the counterpart and is tested with two sets of SPOT and ERS DEM, resulting in a remarkable improvement in DEM. For the analysis of results, the reference DEM is generated from digital base map(1:5000).

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Site Application of Artificial Neural Network for Tunnel Construction (인공신경망을 이용한 터널시공에서 현장 적용성)

  • Song, Joohyeon;Chae, Hwiyoung;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.8
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    • pp.25-33
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    • 2012
  • Although it is important to reflect the accurate information of the ground condition in the tunnel design, the analysis and design are conducted by limited information because it is very difficult to consider various geographies and geotechnical conditions. When the tunnel is under construction, examination of accurate safety and prediction of behavior are overcome the limits of predicting behavior by Artificial Neural Network in this study. First, construct the suitable structure after the data of field was made sure by the multi-layer back propagation, then apply with algorithm. Employ the result of measured data from database, and consider the influence factor of tunnel, like supporting pattern, RMR, Q, the types of rock, excavation length, excavation shape, excavation over, to carry out the reliable analysis through field applicability of Artificial Neural Network. After studying, using the ANN model to predict the shearing displacement, convergence displacement, underground displacement, Rock bolt output follow the excavation over of tunnel construction field, then determine the field applicability with ANN through field measured value and comparison analysis when tunnel is being constructed.

Analysis of two dimensional coefficient of permeability using Electrical logging and AMT Survey (전기검층과 전자탐사를 이용한 2차원 투수계수분포 특성 분석)

  • 고성일;이종호;이태종;박남윤;추석연
    • Proceedings of the Korean Society for Rock Mechanics Conference
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    • 2003.03a
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    • pp.113-120
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    • 2003
  • The estimation of the coeff. of permeability is a major process that influenced in very large portion to the changing of gound water movement and estimation of the outflow’s quantity in the ground water movement modelling. To overcome the error caused by difficulty of the ground investigation for the hydraulic parameter’s estimation, in this paper, we study of correlation between electric resistivity and coeff. of permeability, and analyse of coeff. of permeability from electric resistivity. To accomplish this purpose, we carry out electrical logging, AMT survey as an in-situ test, and measure electric resistivity, porosity, permeability for the intact rock as a laboratory test. Based on the results of this research, it can be applied that estimation of the coeff. of permeability using electrical logging and AMT survey is a effective method for the impossible area of the ground investigation caused by geographical condition and petition.

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A Discourse Analysis to Public Library Ecosystem in Korea (국내 공공도서관 생태계의 담론적 분석)

  • Yoon, Hee-Yoon
    • Journal of the Korean Society for Library and Information Science
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    • v.51 no.1
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    • pp.5-27
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    • 2017
  • The goal of this study is to suggest various improvements and expanding strategies of the public library ecosystem. For this goal, researcher reviewed and analyzed the realistic landscapes and social recognitions about the public library ecosystem as local public goods, and discoursed the basic principles and structural terrain of public library ecosystem based on natural ecosystem. As a result, researcher proposed multifaceted alternatives (ensure library's identity and publicity applying Law of Karma, strengthen librarian's professionalism on the premise of overcoming the Minerva's syndrome, optimize the library service and collection management based on the Pareto principle, reduce reading room and differentiated program through resolution of Halo effect, eliminate usage bias by life cycle based on the Gauss distribution, acceptance of the digital paradigm and use-friendly spatialization that ruminates the Icarus paradox, incorporate small library into public library system through a clear understanding of the Gresham's law, and enforce communication and spread social and cultural value through the practice of the Pompeii paradox).

Development of Hybrid Spatial Information Model for National Base Map (국가기본도용 Hybrid 공간정보 모델 개발)

  • Hwang, Jin Sang;Yun, Hong Sik;Yoo, Jae Yong;Cho, Seong Hwan;Kang, Seong Chan
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.4_1
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    • pp.335-341
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    • 2014
  • The main goal of this study is on developing a proper brand-new data of national base map and Data Based(DB) model for new information technology environments. To achieve this goal, we generated a brand-new Hybrid spatial information model which is specialized in the spatio-temporal map structure, the framework map for information integration, and the multiple-layered topology structure. The DB structure was designed to reflect the change of objections by adding a new dimension of 'time' in the spartial information, while the infrastructure was able to connect/converge with other information by giving the unique ID and multi-scale fusion map structure. Furthermore, the topology and multi visualization structure, including indoor and basement information, were designed to overcome limitations of expressing in 2 dimension map. The result from the performance test, which was based on the Hybrid spatial information model, confirms the possibility in advanced national base map and conducted DB model through implementing various information and spatiotemporal connections.