• 제목/요약/키워드: Accuracy Assessment

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도로설계를 위한 LiDAR 데이터의 활용성 분석 (The analysis of Utilization of LiDAR data in road design)

  • 이현직;박은관;박원일
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2007년도 춘계학술발표회 논문집
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    • pp.363-366
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    • 2007
  • Road Design is being reached to the working design to produce drawings, calculate construction quantity and cost, through the basic design that contained feasibility study and all impact assessment. In general, to plan the route we use topographic map. The vertical positional accuracy is 30cm and horizontal positional accuracy is 35cm in 1:1,000 scale topographic map. In LiDAR, vertical positional accuracy is 15cm and horizontal positional accuracy is 30cm. So if we use LiDAR on road design, more accurate earth-volumn will be calculated when we plan the route. In this paper we try to find the method to use the LiDAR data on road design by drawing the profile and cross sectional view and comparing the earth-volumn to the road that working design is in process adopting the topographic map and LiDAR data.

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FDB를 이용한 비접근지역의 수치지도 제작 가능성 평가 (Assessment of Possibility for Unaccessible Areas Digital Mapping Using FDB)

  • 강준묵;이병걸;임영빈;장영일
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2007년도 춘계학술발표회 논문집
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    • pp.341-344
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    • 2007
  • National Geospatial-Intelligence Agency(NGA) developed VPF in mid 1980 to digitalize military geospatial information. However, because VPF is very complicated system and was severly inefficient in producing, maintaining, and managing the data, VPF was required to be replaced by more efficient data format. These requests resulted in an integrated schema, and eventually VPF. The main idea of using FDB in the production of digital map of non-accessible area is to increase the accuracy. This research focuses on the production of high accuracy digital map by utilizing the FDB. The accuracy of digital map by FDB and by DGN was individually compared with 1m CIB imagery of the Korean peninsula. By analyzing 38 check points based on CIB, DGN showed RMSE of 52m X axis and 49m Y axis. FDB showed 15m in X axis and 13m in Y axis. These results show that the digital map produced using FDB has much higher accuracy than DGN based digital map.

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3차원 좌표 특정기의 오차 평가 시스템 개발 (Development of the system for error evaluation in coordinate measuring machines)

  • 박희재
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1991년도 추계학술대회 논문집
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    • pp.116-120
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    • 1991
  • Technique of length measurement error is widely used in the accuracy assessment of CMMS(Coordinate measuring machines) and machine tools, as it is simple and direct measurement within the working volume of a machine. In this paper, a new method is proposed for the evaluation of the length measurement error in relation to the volumetric accuracy. lD, 2D, and 3D measuring lines are considered for recpective length measurement error: 1D, 2D, and 3D length measurement uncertainties are evaluated from volumetric accuracy. The relationship between the volumetric accuracy md length measurement error to is discussed. PC based system for length measurement error evaluation and simulation is developed.

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단기 전력수요예측 정확도 개선을 위한 대표기온 산정방안 (Representative Temperature Assessment for Improvement of Short-Term Load Forecasting Accuracy)

  • 임종훈;김시연;박정도;송경빈
    • 조명전기설비학회논문지
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    • 제27권6호
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    • pp.39-43
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    • 2013
  • The current representative temperature selection method with five cities cannot reflect the sufficient regional climate characteristics. In this paper, the new representative temperature selection method is proposed with the consideration of eight representative cities. The proposed method considered the recent trend of power sales, the climate characteristics and population distribution to improve the accuracy of short-term load forecasting. Case study results for the accuracy of short-term load forecasting are compared for the traditional temperature weights of five cities and the proposed temperature weights of eight cities. The simulation results show that the proposed method provides more accurate results than the traditional method.

Development of a Semi-automatic Search Program for Crown Delineation Based on Watershed and Valley Following Algorithms

  • Sim, Woodam;Park, Jeongmook;Lee, Jungsoo
    • Journal of Forest and Environmental Science
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    • 제34권2호
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    • pp.142-144
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    • 2018
  • This paper discusses the development of semi-automatic search program for crown delineation in stand level. The crown of an individual tree was delineated by applying the Watershed (WS) and Valley Following (VF) algorithms. Unmanned Aerial Vehicle (UAV) images were used in the semi-automatic search program to delineate the crown area. The overall accuracy and Khat were used in accuracy assessment. WS algorithm's model showed the overall accuracy and Khat index of 0.80 and 0.59, respectively, in Plot 1. However, the overall accuracy and Khat of VF algorithm's model were 0.78 and 0.51, respectively, in Plot 2.

Extraction of Spatial Characteristics of Cadastral Land Category from RapidEye Satellite Images

  • La, Phu Hien;Huh, Yong;Eo, Yang Dam;Lee, Soo Bong
    • 한국측량학회지
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    • 제32권6호
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    • pp.581-590
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    • 2014
  • With rapid land development, land category should be updated on a regular basis. However, manual field surveys have certain limitations. In this study, attempts were made to extract a feature vector considering spectral signature by parcel, PIMP (Percent Imperviousness), texture, and VIs (Vegetation Indices) based on RapidEye satellite image and cadastral map. A total of nine land categories in which feature vectors were significantly extracted from the images were selected and classified using SVM (Support Vector Machine). According to accuracy assessment, by comparing the cadastral map and classification result, the overall accuracy was 0.74. In the paddy-field category, in particular, PO acc. (producer's accuracy) and US acc. (user's accuracy) were highest at 0.85 and 0.86, respectively.

모델의 불확실성이 구조물의 손상예측정확도에 미치는 영향 (Damage Prediction Accuracy as a Function of Model Uncertainty in Structures)

  • 김정태
    • 전산구조공학
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    • 제7권3호
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    • pp.153-166
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    • 1994
  • 구조물의 손상예측정확도를 모델불확실성의 함수로 산정하는 방법론이 제시되었다. 먼저, 구조물의 손상발생위치과 크기를 결정할 수 있는 알고리즘의 요약되고 모델불확실성과 손상발견정확도를 측정하는 방법들이 제시되었다. 다음으로, 실존구조물의 손상발견정확도에 미치는 모델불확실성의 영향을 산정하는 방법론이 제시되었다. 마지막으로, 한개의 진동모드가 측정된 Plate-Girder교량을 사용하여 이같은 산정방법론의 적합성이 예증되었다.

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Automatic Generation of a SPOT DEM: Towards Coastal Disaster Monitoring

  • Kim, Seung-Bum;Kang, Suk-Kuh
    • 대한원격탐사학회지
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    • 제17권2호
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    • pp.121-129
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    • 2001
  • A DEM(digital elevation model) is generated from a SPOT panchromatic stereo-pair using automated algorithms over a 8 km$\times$10 km region around Mokpo city. The aims are to continue the accuracy assessment over diverse conditions and to examine the applicability of a SPOT DEM for coastal disaster monitoring. The accuracy is assessed with respect to three reference data sets: 10 global positioning system records, 19 leveling data, and 1:50,000 topography map. The planimetric error is 10.6m r.m.s. and the elevation erroer ranges from 12.4m to 14.4m r.m.s.. The DEM accuracy of the flat Mokpo region is consistent with that over a mountainous area, which supports the robustness of the algorithms. It was found that coordinate transformation errors are significant at a few meters when using the data from leveling and topographic maps. The error budget is greater than the requirements for coastal disaster monitoring. Exploiting that a sub-scene is used, the affine transformation improves the accuracy by 50% during the camera modeling.

Hazard analysis and monitoring for debris flow based on intelligent fuzzy detection

  • Chen, Tim;Kuo, D.;Chen, J.C.Y.
    • Structural Monitoring and Maintenance
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    • 제7권1호
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    • pp.59-67
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    • 2020
  • This study aims to develop the fuzzy risk assessment model of the debris flow to verify the accuracy of risk assessment in order to help related organizations reduce losses caused by landslides. In this study, actual cases of landslides that occurred are utilized as the database. The established models help us assess the occurrence of debris flows using computed indicators, and to verify the model errors. In addition, comparisons are made between the models to determine the best one to use in practical applications. The results prove that the risk assessment model systems are quite suitable for debris flow risk assessment. The reproduction consequences of highlight point discovery are shown in highlight guide coordinating toward discover steady and coordinating component focuses and effectively identified utilizing these two systems, by examining the variety in the distinguished highlights and the element coordinating.

손상지수를 이용한 철근콘크리트 교각의 내진성능평가 (Seismic Performance Assessment of Reinforced Concrete Bridge Piers using Damage Indices)

  • 김태훈;정영수;신현목
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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    • pp.144-147
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    • 2003
  • This paper presents a nonlinear finite element analysis procedure for the seismic performance assessment of reinforced concrete bridge piers using damage indices. The accuracy and objectivity of the assessment process may be enhanced by the use of sophisticated nonlinear finite element analysis program. A computer program, named RCAHEST(Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Damage indices aim to provide a means of quantifying numerically the damage reinforced concrete bridge piers sustained under earthquake loading. The proposed numerical method for the seismic performance assessment of reinforced concrete bridge piers is verified by comparison with the reliable experimental results.

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