• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.11
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• pp.1047-1053
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• 2017

The range data acquired by 2D/3D LIDAR, a core sensor for autonomous navigation of an unmanned ground vehicle, is effectively used for ground modeling and obstacle detection. Within the ambiguous boundary of a road environment, however, LIDAR does not provide enough information to analyze the traversable region. This paper presents a new method to analyze a candidate area using the characteristics of LIDAR reflectivity for better detection of a traversable region. We detected a candidate traversable area through the front zone of the vehicle using the learning process of LIDAR reflectivity, after calibration of the reflectivity of each channel. We validated the proposed method of a candidate traversable region detection by performing experiments in the real operating environment of the unmanned ground vehicle.

• 전자공학회논문지 IE
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• v.46 no.1
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• pp.7-15
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• 2009

In this paper, automatic structure boundary extraction is proposed using terrestrial LIDAR (Light Detection And Ranging) in 3-dimensional data. This paper describes an algorithm which does not use pictures and pre-processing. In this algorithm, an efficient decimation method is proposed, considering the size of object, the amount of LIDAR data, etc. From these decimated data, object points and non-object points are distinguished using distance information which is a major features of LIDAR. After that, large and small values are extracted using local variations, which can be candidate for boundary. Finally, a boundary line is drawn based on the boundary point candidates. In this way, the approximate boundary of the object is extracted.

• Korean Journal of Remote Sensing
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• v.24 no.4
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• pp.333-340
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• 2008

For the indoor spatial modeling by terrestrial LiDAR and the analyzing its positional accuracy result, two terrestrial LiDARs which have different specification each other were used at test site. This paper shows disparity of accuracy between (1) the structural coordinate transformation by point cloud unit using control points and (2) the relative registration among all point cloud units then structural coordinate transformation in bulk, under condition of limited number of control points. As results, the latter had smaller size and distribution of errors than the former although different specifications and acquistion methods are used.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.2
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• pp.33-40
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• 2014

At present, Cadastral map of 2 dimensional is in the stream of changing it to 3 dimensional type supported by GPS and laser techniques. In addition, this steam can be explained at the same time with improvement of equipment of storing much information, support of equipment for imaginative 3D spatial information, and support of equipment of expressing land in 3D Cadastral. This study suggest to apply airborne lidar survey technique on cadastral map to acquire comparably and quickly detailed height of ground. For doing this, this study checked out credibility regarding accuracy of airborne lider survey. After choosing research area, this study has done the airborne lidar survey and acquire the result after surveying Cadastral Comparison Point to check out the accuracy of acquired results. In addition, this study check out the result of Cadastral Comparison Point and airborne lidar survey applied by paired sample t-test based on actual results. The result is that test statistics is 0.322 which is 5 % similar level and null hypothesis cannot be rejected, so this study found out that result of both survey ways are the same. Therefore, the result of airborne lidar survey can be utilized to build up 3D Cadastral information hereafter.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2023.10a
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• pp.92-93
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• 2023

• Spatial Information Research
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• v.16 no.3
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• pp.279-290
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• 2008

Landslide, one of the serious natural disasters, has Incurred a large loss of human and material resources. Recently, many forecasting or alarm systems based on various kinds of measuring equipment have been developed to reduce the damage of landslide. However, only a few of these equipments are guaranteed to evaluate the safety of whole side of land slope with their accessibility to the slope. In this study, we performed some experiments to evaluate the applicability of a terrestrial LiDAR as a surveying tool to measure the displacement of a land slope surface far a slope collapsing protection system. In the experiments, we had applied a slope stability method to a land slope and then forced to this slope with a load increasing step by step. In each step, we measured the slope surface with both a total station and a terrestrial LiDAR simultaneously. As the result of Slope Fracturing analysis using all targets, the LiDAR system showed that three was 1cm RMSE on X-axis, irregularity errors on Y-axis and few errors on Z-axis compare with Total Station. As the result of Slope Fracturing analysis using continuous targets, the pattern of Slope Fracturing was different according to the location of continuous targets and we could detect a continuous change which couldn't be found using Total station. The accuracy of the LiDAR data was evaluated to be comparable to that of the total station data. We found that a LiDAR system was appropriate to measuring the behaviour of land slope. The LiDAR data can cover the whole surface of the land slope, whereas the total station data are available on a small number of targets. Moreover, we extracted more detail information about the behavior of land slope such as the volume and profile changes using the LiDAR data.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.1
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• pp.97-103
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• 2011

LiDAR system has become a popular tool for generating 3D surface data such as Digital Surface Model. Extraction of valuable information, such as digital building models, from LiDAR data has been an attractive research subject. This research addresses to extract planar patches from LiDAR data. Planar patches are important primitives consisting of man-made objects such as buildings. In order to determine the best fitted planes, this research proposed a method to reduce/eliminate the impact of the outliers and the intersection areas of two planes. After finishing plane fitting, planar patches are segmented by pseudo color values which are calculated by determined three plane parameters for each LiDAR point. In addition, a segmentation procedure is conducted using the pseudo color values to find planar patches. This paper evaluates the feasibility of the proposed method using both airborne and terrestrial LiDAR data.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.1
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• pp.8-15
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• 2011

In this paper, we propose a new structure modeling algorithm from 3D cloud points of terrestrial LADAR data. Terrestrial LIDAR data have various obstacles which make it difficult to apply conventional algorithms designed for air-borne LIDAR data. In the proposed algorithm, the field data are separated into several clusters by adopting the structure extraction method which uses color information and Hough transform. And cluster based Delaunay triangulation technique is sequentially applied to model the artificial structure. Each cluster has its own priority and it makes possible to determine whether a cluster needs to be considered not. The proposed algorithm not only minimizes the effects of noise data but also interactively controls the level of modeling by using cluster-based approach.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.354-355
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• 2000

대기환경문제는 관련 환경정책의 강화와 각종 대책에도 불구하고 그 심각성이 날로 증가하고 있다. 이러한 문제를 해결하기 위해 오염현상에 대한 정확한 측정, 분석과 이를 토대로 한 효율적인 대기오염 대책 수립 및 시행이 요구된다. 그러나 기존의 측정방법으로는 대기오염변화를 신속하게 측정하거나 또는 지상 수십 km에 달하는 광범위한 영역의 농도분포를 측정하는 것이 불가능하다. 최근 들어 실시간 측정이 가능한 원격측정 방법 중의 하나인 라이다 (Light Detection And Ranging; LIDAR)에 대한 관심이 고조되면서 여러 나라에서 급속히 발전하고 있다. (중략)

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.2
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• pp.99-105
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• 2013

In rapidly developing urban areas that include high-rise, large, and complex buildings, indoor and outdoor maps in GIS become a basis for utilizing and sharing information pertaining to various aspects of the real world. Although an indoor mapping has gained much attentions, research efforts are mostly in 2D and 3D modeling of terrain and buildings. Therefore, to facilitate fast and accurate construction of indoor GIS, this paper proposes a semi-automatic method consisting of preprocessing, 2D mapping, and 3D mapping stages. The preprocessing is designed to estimate heights of building interiors and to identify noise data from point clouds. In the 2D mapping, a floor map is extracted with a tracing grid and a refinement method. In the 3D mapping, a 3D wireframe model is created with heights from the preprocessing stage. 3D mesh data converted from noise data is combined with the 3D wireframe model for detail modeling. The proposed method was applied to point clouds depicting a hallway in a building. Experiment results indicate that the proposed method can be utilized to construct 2D and 3D maps for indoor GIS.