• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1D
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• pp.81-88
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• 2012

This present research was carried out by dividing two parts; field surveying and data processing, in order to analyze changed patterns of a shoreline. Firstly, the shoreline information measured by the precise GPS positioning during long duration was collected. Secondly, the algorithm for detecting an auto boundary with regards to the changed shoreline with multi-image data was developed. Then, a comparative research was conducted. Haeundae beach which is one of the most famous ones in Korea was selected as a test site. RTK-GPS surveying had been performed overall eight times from September 2005 to September 2009. The filed test by aerial Lidar was conducted twice on December 2006 and March 2009 respectively. As a result estimated from both sensors, there is a slight difference. The average length of shoreline analyzed by RTK-GPS is approximately 1,364.6 m, while one from aerial Lidar is about 1,402.5 m. In this investigation, the specific algorithm for detecting the shoreline detection was developed by Visual C++ MFC (Microsoft Foundation Class). The analysis result estimated by aerial photo and satellite image was 1,391.0 m. The level of reliability was 98.1% for auto boundary detection when it compared with real surveying data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.2
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• pp.177-187
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• 1999

Up to date, in many application fields of GSIS, we usually have used vector-based spatial overlay or grid-based spatial algebra for extraction and analysis of spatial data. But, because these methods are based on traditional crisp set, concept which is used these methods. shows that many kinds of spatial data are partitioned with sharp boundary. That is not agree with spatial distribution pattern of data in the real world. Therefore, it has a error that a region or object is restricted within only one attribution (One-Entity-one-value). In this study, for improving previous methods that deal with spatial data based on crisp set, we are suggested to apply into spatial overlay process the concept of fuzzy set which is good for expressing the boundary vagueness or ambiguity of spatial data. two methods be given. First method is a fuzzy interval partition by fuzzy subsets in case of spatially continuous data, and second method is fuzzy boundary set applied on categorical data. with a case study to get a land suitability map for the development site selection of new town, we compared results between Boolean analysis method and fuzzy spatial overlay method. And as a result, we could find out that suitability map using fuzzy spatial overlay method provide more reasonable information about development site of new town, and is more adequate type in the aspect of presentation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.5
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• pp.503-514
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• 2016

Delineation of accurate object boundaries is crucial to provide reliable spatial information products such as digital topographic maps, building models, and spatial database. In LiDAR(Light Detection and Ranging) data, real boundaries of the buildings exist somewhere between outer-most points on the roofs and the closest points to the buildings among points on the ground. In most cases, areas of the building footprints represented by LiDAR points are smaller than actual size of the buildings because LiDAR points are located inside of the physical boundaries. Therefore, building boundaries determined by points on the roofs do not coincide with the actual footprints. This paper aims to estimate accurate boundaries that are close to the physical boundaries using airborne LiDAR data. The accurate boundaries are determined from the non-gridded original LiDAR data using initial boundaries extracted from the gridded data. The similar method implemented in this paper is also found in demarcation of the maritime boundary between two territories. The proposed method consists of determining initial boundaries with segmented LiDAR data, estimating accurate boundaries, and accuracy evaluation. In addition, extremely low density data was also utilized for verifying robustness of the method. Both simulation and real LiDAR data were used to demonstrate feasibility of the method. The results show that the proposed method is effective even though further refinement and improvement process could be required.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.4
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• pp.219-231
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• 2019

The specifications of signboards are set for each type of signboards, but the shape and size of the signboard actually installed are not uniform. In addition, because the colors of the signboard are not defined, so various colors are applied to the signboard. Methods for recognizing signboards can be thought of as similar methods of recognizing road signs and license plates, but due to the nature of the signboards, there are limitations in that the signboards can not be recognized in a way similar to road signs and license plates. In this study, we proposed a methodology for recognizing plate-type signboards, which are the main targets of illegal and old signboards, and automatically extracting areas of signboards, using the deep learning-based Faster R-CNN algorithm. The process of recognizing flat type signboards through signboard images captured by using smartphone cameras is divided into two sequences. First, the type of signboard was recognized using deep learning to recognize flat type signboards in various types of signboard images, and the result showed an accuracy of about 71%. Next, when the boundary recognition algorithm for the signboards was applied to recognize the boundary area of the flat type signboard, the boundary of flat type signboard was recognized with an accuracy of 85%.

• Journal of Korean Society for Geospatial Information Science
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• v.11 no.3 s.26
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• pp.55-63
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• 2003

Korean cadastral system is primarily based on the graphical maps, thus, map reproduction by excessive shrinkage or extension, map mishandling and imperfection of surveying techniques have created cadastral non-coincident areas, which caused public distrust as well as considerable difficulties in land administration and policy making. Therefore, in this study, the methodologies for the resolution of the non-coincident problem are presented by means of a comparative analysis between cases of the non-coincident areas. The non-coincidence caused by the mismatch of parcel boundaries can be settled by introducing a coordinate-based system namely ${\ulcorner}$Integrated Land Information System${\lrcorner}$, meanwhile, those by other reasons can be done by establishing and executing a plan that can deliver the unification of the cadasoal and the land registration systems. Governmental intention and budgetary measures for securing the project expenses are essential to make this feasible. If the comprehensive improvement project is completed, the cadastral registers that define the parcel boundary, area and ownership will recover public confidence, which in turn secures land owners' rights by promoting land markets and stabilizing land prices.

• Journal of Korean Society for Geospatial Information Science
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• v.9 no.2 s.18
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• pp.47-54
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• 2001

The aim of this study is to represent the effective method for undertaking cadastral surveying works through analyzing and comparison of the surveying results both Total Station and GPS surveying techniques. in the value of coordinate of land parcels, the surveying results of using Total Station and Real Time Kinematic GPS surveying are compared and anayzed. As a results, each axis X and Y differences are ${\Delta}X=0.02m\;and\;{\Delta}Y=0.02$. Therefore the latter surveying method is available to use for production of numerical casdastral map at a large scale and for field surveying in farmland adjustment area. Furthermore travers surveying is not needed to be done when horizontal position of the boundary of a land parcel is determined by the method of RTK. It is recognized as a effective and efficient method in rapaid, accurate and economical aspects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.1-9
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• 2020

Acritical function of a nation is to protect its people's lives and properties from natural disasters such as a drought. A drought affects many aspects of human life, including social, economic, and industrial activities. Approximately 75.7% of reservoirs in Korea are over 50 years old.Sedimentation over the years may have caused a situation where storage capacity of the reservoirs is no longer sufficient and compliant with the original reservoir specifications. This study analyzes storage capacities for ten aged reservoirs using the autonomous navigation USV. It compares these capacities with sediment estimated by conventional empirical equations. Comparisons were made to the original specifications for the reservoirs.Storage capacity of six reservoirs decreased in a range between 16.2%-55.3% and storage capacity of 4 reservoirs increased in a range between 1.5%-380.2%. This data was compared to data derived from estimating sediment by empirical equations. Yoon's equation(1982) appeared more accurate than Sur's equation(1988) in Uhlinzi and Yongpo reservoirs, and Sur's equation(1988), however, appeared more accurate than Yoon's equation in Daegok, Ugok2 and Ochi reservoirs. The significant ranges of sedimentation shown in this study suggest that it is worth continuously surveying reservoirs to ensure their efficient management and operation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.3
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• pp.269-275
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• 2003

The cadastral system which accomplishes the base of national land administration with accuracy of proper data and the cadastral maintenance quickly is agreeing with the actual place in information ages in Inundation. But even in spite of many efforts, various Problems are exposed in accuracy of the data on the cadastral maps and local situation must agree accurately from the process which propels cadastral information systems. Therefore, it must be carried out the cadastral non correspondence arrangement first of all in link of the plan which it corrects the error of existing data and computerization quickly. It summarizes the research as follows ; Cadastral non correspondence of the land boundaries on the map and actual circumstance does not agree with cadastral maps accurately, The lands which exceed the standards with the position error excess of 50cm on lil ,200 and 240cm on 1/6,000 areas on the map scale are the registration correction objectives. It is investigated that the cadastral non correspondence parcels occur in various cause and long period, the area error corrections are mainly objectives, and about 80% of the test area comes to reveal within permitted the limit of the measurement of planimetric area for cadastral survey, so it is not difficult with the fact that the compensation back which it follows in area increase and decrease and the location error correction becomes the important object fer the cadastral non correspondence arrangement projects.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.3
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• pp.253-259
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• 2004

The sheetwise cadastral map data needs to become a Serial Cadastral Map (SCM) database for the promotion of the reliability of cadastral surveying, for the efficient operation of the Parcel Based Land Information System, and for the convenient use of land information as well. A large amount of money and time are required for the editing process of producing SCM DB in accordance with the $\ulcorner$Guideline for the Production of Serial Cadastral Maps$\lrcorner$ by the Ministry of Construction & Transportation if any of field surveying techniques is accompanied by. In addition, a boundary line that extends to a neat line does not meet the counterpart of the neighboring map sheet at a point. Such cases frequently occur and are much dependent upon the decisions of individuals in charge of editing or inspecting. The core processes of the research, firstly overlay SCM produced by the edition of the sheetwise cadastral maps with Autodesk Map on orthophoto images, secondly adjust the parcel boundaries which are delineated over more than one map sheet, and lastly compare the original boundary coordinates and areas with the corresponding adjusted ones and calculate root mean square errors (RMSEs). The research aims at promoting the quality of SCM by minimizing the inconsistency of parcel boundaries by means of the comparative analysis of the calculated RMSEs.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.281-286
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• 2005

여러 분야에서 활용성이 증가하고 있는 도시지역에 대한 3차원 모형화 구축은 기존에는 항공사진이나 고해상도 위성영상을 주로 활용하여 왔으나, 최근에는 높은 정밀도를 보장하는 항공LIDAR 측량기법에 대한 연구가 활발히 진행되고 있다. 특히, 다양한 형태, 크기, 종류의 건물들이 존재하는 광범위한 도시지역을 모형화 하기 위하여 정밀도가 높은 LIDAR 자료를 통하여 신속하고 정확하게 현실에 가까운 건물 모형으로 복원하는 기술 개발이 요구되고 있다. 본 연구에서는 LIDAR 관측자료 및 디지털 영상, 수치지도 등의 자료를 활용하여 LIDAR자료의 전처리 과정과 다양한 필터를 적용하여 지면과 비지면 정보를 분류하였으며, LoG 연산자에 의한 건물 경계선 및 특징점 추출기법을 개발하여 도시 지역의 3차원 건물 복원기법을 제안하였다.