• 제목/요약/키워드: DEMS

검색결과 129건 처리시간 0.022초

Uncertainty Analysis of Flash-flood Prediction using Remote Sensing and a Geographic Information System based on GcIUH in the Yeongdeok Basin, Korea

  • Choi, Hyun;Chung, Yong-Hyun;Yoon, Hong-Joo
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.884-887
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    • 2006
  • This paper focuses on minimizing flood damage in the Yeongdeok basin of South Korea by establishing a flood prediction model based on a geographic information system (GIS), remote sensing, and geomorphoclimatic instantaneous unit hydrograph (GcIUH) techniques. The GIS database for flash flood prediction was created using data from digital elevation models (DEMs), soil maps, and Landsat satellite imagery. Flood prediction was based on the peak discharge calculated at the sub-basin scale using hydrogeomorphologic techniques and the threshold runoff value. Using the developed flash flood prediction model, rainfall conditions with the potential to cause flooding were determined based on the cumulative rainfall for 20 minutes, considering rainfall duration, peak discharge, and flooding in the Yeongdeok basin.

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RSA vs DEM in view of particle packing-related properties of cementitious materials

  • Li, Kai;Stroeven, Piet
    • Computers and Concrete
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    • 제22권1호
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    • pp.83-91
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    • 2018
  • Various systems for simulating particulate matter are developed and used in concrete technology for producing virtual cementitious materials on the different levels of the microstructure. Basically, the systems can be classified as two distinct families, namely random sequential addition systems (RSAs) and discrete element methods (DEMs). The first type is hardly being used for this purpose outside concrete technology, but became popular among concrete technologists. Hence, it is of utmost relevance to compare the two families in their capabilities, so that the reliability of produced data can be estimated. This paper pursues to do this on the basis of earlier published material of work performed by a succession of PhD students in the group of the second author. Limited references will be given to external sources.

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

  • Choi, Jung-Hyun;Lee, Chang-Wook;Won, Joong-Sun
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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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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More Efficient Method for Determination of Match Quality in Adaptive Least Square Matching Algorithms

  • Lee, Hae-Yeoun;Kim, Tae-Jung;Lee, Heung-Kyu
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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    • pp.274-279
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    • 1998
  • For the accurate generation of DEMs, the determination of match quality in adaptive least square matching algorithm is significantly important. Traditionally, only the degree of convergence of a solution matrix in least squares estimation has been considered for the determination of match quality. It is, however, not enough to determine the true match quality. This paper reports two approaches of match quality determination based on adaptive least square correlation : the conventional if-then logic approaches with scene geometry and correlation as additional quality measures; and, the fuzzy logic approaches. Through these, accurate decision of match quality will minimize the number of blunder and maximize the number of exact match. The proposed methods have been tested on JERS and SPOT images and the results show good performance.

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인터넷 수문관측시스템을 이용한 도시수문 모니터링 (Urban Hydrologic Monitoring due to Internet Hydrologic Monitoring System)

  • 서규우;김남길;나현우;이인록
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2004년도 학술발표회
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    • pp.1321-1325
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    • 2004
  • The continuous monitoring of the runoff in the small-scaled urban watershed and easily accessible experiment catchment is necessary to investigate the overall status of the development in the urban catchment and the varying aspects of the discharge characteristics due to the urbanization. However, the research on the management and the characteristics of the small-scaled model basin for discharge tests has not been actively performed up to now. This study selects the Dong-Eui university basin, which locates at Gaya-dong in Busan, as the experiment catchment to monitor the discharge rate in the urban watershed. EMS(DEMS, DATA-PCS EMS, mini rain gage & AWS(AWS-DEU, DATA-PCS AWS) monitoring system installed for the collection of hydrological data such as the rainfall and the waterlevel. This experiment catchment is the typical urban catchment and is under development, and it is possible to analyze the varying aspects of the discharge rate during and after the development.

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IKONOS 위성영상의 3차원 위치 결정 모형화 기법 개발 (Development of Modeling Method for 3-D Positioning of IKONOS Satellite Imagery)

  • 진경혁;홍재민;유환희;유복모
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2004년도 추계학술발표회 논문집
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    • pp.269-274
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    • 2004
  • Recent adoption of the generalized sensor model to IKONOS and Quickbird satellite imagery have promoted various research activities concerning alternative sensor models which can replace conventional physical sensor models. For example, there are the Rational Function Model(RFM), the Direct Linear Transform(DLT) and the polynomial transform. In this paper, the DLT model which uses just a few number of GCPs was suggested. To evaluate the accuracy of the proposed DLT model, the RFM using 35 GCPs and the bias compensation method(Fraser et al., 2003) were compared with it. Quantitative evaluation of 3B positioning results were performed with independent check points and the digital elevation models(DEMs). In result, a 1.9- to 2.2-m positioning accuracy was achieved for modeling and DEM accuracy is similar to the accuracy of the other model methods.

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수치지도 갱신을 위한 3차원 일반화와 논리적 오류수정 (3D Generalization and Logical Error Correction for Digital Map Update)

  • 이진형;이동천;박기석;박청
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2009년도 춘계학술발표회 논문집
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    • pp.29-34
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    • 2009
  • Map update is required to provide up-to-date information. In update process, the most adequate generalization is to be applied to all scales of maps simultaneously. Most of existing maps are composed of 2D data and represented in 2D space. However, maps for next generation are to be generated with 3D spatial information including ortho-images and DEMs. Therefore, 3D generalization is necessary for 3D digital map update. This paper proposes methods for 3D generalization and correction for logical errors possibly accompanied with generalization.

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효율적 코드변환 알고리즘에 기반한 PLC 의 체계적 설계 (Systematic Design of Programmable Logic Controller Based on Efficient Code Conversion Algorithm)

  • 차종호;조광현
    • 제어로봇시스템학회논문지
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    • 제7권12호
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    • pp.1009-1014
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    • 2001
  • The ladder diagram (LD) for programmable logic controllers (PLCs) ar responsible for much important roles in advance industrial automation. As automated systems become more complex the design procedures of the system become more difficult as well. Hence. the design automation issues based on discrete event models(DEMs) are receiving more attention. One of the popular ways of tackling these problems is employing Petri nets. In this paper, we use the modified automation Petri net(MAPN) to model the manufacturing system and the modified token passing logic (MTPL) method conversion (ECC) algorithm based on the MAPN and the MTPL Finally, an example of the manufacturing system is provided to illustrate the proposed ECC algorithm.

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Geometric Corrections of Inaccessible Area Imagery by Employing a Correlative Method

  • Lee, Hong-Shik;Park, Jun-Ku;Lim, Sam-Sung
    • 대한공간정보학회지
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    • 제10권5호
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    • pp.67-74
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    • 2002
  • The geometriccorrection of a satellite imagery is performed by making a systematic correction with satellite ephemerides and attitude angles followed by employing the Ground Control Points (GCSs) or Digital Elevation Models (DEMs). In a remote area or an inaccessible area, however, GCPs are unavailable to be surveyed and thus they can be obtained only by reading maps, which are not accurate in reality. In this study, we performed the systematic correction process to the inaccessible area and the precise geometric correction process to the adjacent accessible area by using GCPs. Then we analyzed the correlation between the two geo-referenced Korea Multiurpose Satellite (KOMPSAT-1 EOC) images. A new geometrical correction for the inaccessible area imagery is achieved by applying the correlation to the inaccessibleimagery. By employing this new method, the accuracy of the inaccessible area imagery is significantly improved absolutely and relatively.

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비행안전구역 건물 높이 평가에서 수치지형도로 제작한 DEM의 활용성 (The Utilization of DEM Made by Digital Map in Height Evaluation of Buildings in a Flying Safety Area)

  • 박종철;김만규;정웅선;한규철;류영기
    • 한국지리정보학회지
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    • 제14권3호
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    • pp.78-95
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    • 2011
  • 본 연구에서는 1:5,000 수치지형도를 이용하여 서로 다른 보간 방법으로 다양한 공간해상도를 갖는 여러 가지 DEM을 제작하였다. 그리고 제작한 다양한 DEM의 수직정확도를 network RTK GPS survey를 통해 획득한 다수의 검사점 자료를 활용하여 평가하였다. 연구 결과 전반적인 RMSE 값, 토지 유형별 RMSE 값 및 단면 평가(profile evaluation) 결과 등을 고려할 때 TIN 기반의 Terrain 방법으로 제작한 DEM이 비행안전구역에서의 신축건물 고도제한 평가에 유용함을 알 수 있었다. 그리고 비행안전구역에서의 신축건물 고도제한 평가에 적합한 DEM의 공간해상도는 3m임을 알 수 있었다. 한편, 제작한 DEM으로 획득한 지형고도 값(elevation value)은 점 추정 값(point estimation value)이 아닌 구간 추정 값(interval estimation value)이다. 이는비행장 주변의 잠재적인 신축 예정 건물의 높이가 그 지역에 설정된 제한 고도 값(height limitation value)에 저촉되는지에 대한 여부를 평가하는 데 활용할 수 있다. 본 연구에서는 구간 추정 값인 신축건물의 높이 값이 제한 고도 값에 저촉될 가능성을 3단계로 나누어 평가하는 방안을 제시하였다 - 1) 저촉 가능성 매우 높음, 2) 저촉 가능성 매우 낮음, 3) 저촉 가능성 판단 어려움. 본 연구의 결과는 비행장 주변 건물 고도제한 평가 관련 지리정보시스템(GIS)을 개발하는 데 중요한 기초를 제공한다. 아울러, 연구지역에 한정된 값이기는 하지만, 2차원 수치지형도를 활용하여 제작한 DEM의 수직정확도 값은 DEM을 이용하고자 하는 연구자들에게 의미 있는 유용한 정보가 될 것이다.