• The Journal of the Korean dental association
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• v.56 no.9
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• pp.462-478
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• 2018

The presence of implant-prosthesis misfits can cause various complications. It is very important to detect misfits to prevent such complications. There are various evaluation methods for misfit assessment including clinical methods and laboratory in vitro methods. The clinical misfit evaluation includes radiographic analysis, visual observation, probing, Sheffield test, evaluation with disclosing materials, and screw resistance test. The laboratory in vitro evaluation method includes indirect modelling evaluation and direct metrological visualization. Of the indirect modelling methods, photoelastic stress analysis, finite element analysis, strain gauge analysis, and microbial colonization analysis were reviewed. Of the direct metrological visualization, microscopic analysis, 3-D photogrammetric analysis, coordinate measuring analysis, and radiographic analysis were reviewed. In this review, the characteristics, advantages and disadvantages of each method were evaluated.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1003-1009
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• 2009

The Spatial Image contents of Geomorphology 3-D environment is focused by the requirement and importance in the fields such as, national land development plan, telecommunication facility management, railway construction, general construction engineering, Ubiquitous city development, safety and disaster prevention engineering. The currently used DEM system using contour lines, which embodies geographic information based on the 2-D digital maps and facility information has limitation in implementation in reproducing the 3-D spatial city. Moreover, this method often neglects the altitude of the rail way infrastructure which has narrow width and long length. This As the results, We confirmed the solutions of varieties application for railway facilities management using 3-D spatial image contents and database design. Also, I suggested that U-city using railway modeling about matching methods of high density elevation value using 3-D aerial photo with laser data are best approach for detail stereo modeling and simulation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.1
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• pp.21-27
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• 2004

It will be a real good news fer the people who were lost their hometown by the construction of a large dam to be restored to the farmer state. Focused on Cheung-pyung around where most part were submerged by the Chungju large Dam founded in eurly 1980s, It used remote sensing image restoration Technique in this study in order to restore topographical features before the flood with stereo effects. We gathered comparatively good satellite photos and remotely sensed digital images, then its made a new fusion image from these various satellite images and the topographical map which had been made before the water filled by the DAM. This task was putting together two kinds of different timed images. And then, we generated DEM including the outskirts of that area as matching current contour lines with the map. That could be a perfect 3D image of test areas around before when it had been water filled by making perspective images from all directions included north, south, east and west, fer showing there in 3 dimensions. Also, for close range visiting made of flying simulation can bring to experience their real space at that time. As a result of this experimental task, it made of new fusion images and 3-D perspective images and simulation live images by remotely sensed photos and images, old paper maps about vanished submerged Dam areas and gained of possibility 3-D terrain image restoration about submerged area by large Dam construction.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.349-353
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• 2003

최근 관심이 증대되고 있는 국토모니터링과 관련하여 기존의 SPOT, IRS, KOMPSAT, LANDSAT 등의 중ㆍ저해상도 위성영상과 IKONOS 등의 고해상도 위성영상을 이용하여 국토의 변화를 탐지하고자 하는 시도가 활발히 진행되고 있다. 이 때 영상의 기하보정은 필수적인 과정이며 영상의 기하보정시 기준점을 취득하는 과정에 많은 시간과 작업비용이 소요된다. 현재 기준점 취득은 수치지도 등을 통해 기존의 지상기준점을 이용하는 방법과 GPS를 이용한 현지 측량방법이 활용되고 있는데 동일지역에 대해 매번 사업 때마다 수행되고 있는 실정이다. 따라서 이러한 과정을 보다 효율적으로 수행하기 위한 하나의 방안으로 본 연구에서는 image chip을 이용하여 GCP를 취득하고 이를 데이터베이스로 구축하여 기존의 작업을 자동화, 체계화하고자 하였다. 이를 통하여 중복측량 방지와 데이터의 균질성을 기할 수 있었다. Image Chip의 영상 정합을 위해서는 상관계수법과 최소제곱정합법을 이용하여 부영상소 단위까지 정합결과를 얻을 수 있었으며 위성의 header 정보로부터의 영상의 표정각과 입사각에 대한 정보를 이용하여 축척과 회전요소를 고려함으로써 영상 정합시 보다 정확한 기준점 정보를 취득할 수 있었다. 또한, 이종 센서간 영상정합 가능성에 대해서 연구한 결과 KOMPSAT과 SPOT간에는 신뢰할 만한 수준의 정합 결과를 얻을 수 있었으나 고해상도 영상의 경우에는 항공사진과 IKONOS의 영상 정합시 센서의 방사학적 특성의 차이로 신뢰할 안한 결과를 얻을 수 없었다. 영상 정합시 정확도에 영향을 미치는 인자들에 관한 실험 결과 센서의 파장, 계절, Chip 영상의 크기 등이 큰 영향을 미쳤으며 영상정합을 위해 영상 GCP를 데이터베이스에서 검색할 때 이에 대한 고려가 우선적으로 이루어져야 할 것으로 사료된다.n of hub-and-spoke system, integration of logistics bases, introduction of (automatic) parking building, diversification of transportation mode, and etc. At the same time, we constructed three practically executable scenarios based on those ideas. The first is "Center Hub" scenario, the second is "Metropolitan Hub" scenario. The third and last scenario is "Regional Consolidation of Warehouses (distribution centers)".f worldly desire' and 'cordiality' that one could be deserved his diligency becoming a part of the harmonious idealistic living place. Fourthly, on the character of story teller. Originally he is a incomer of "Gang-Ho" from real world. so that reason, he is showing dualism not to deny the loyalty oath to his king, while he intends to satisfy with the life in "Gang- Ho" separating himself from real world. As a gentry, at that time, the loyalty oath is inevitable one and that is found from wr

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.5
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• pp.379-387
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• 2006

The real world is spatially modelled conceptually either as discrete objects or earth surface. The generated data models are then usually represented as vector and raster respectively. Although there are limited cases where only one data model is sufficient to solve the spatial problem at hand, it is now generally accepted that GIS should be able to handle various types of data model. Recent advances in spatial technology introduced even more variety of heterogeneous data models and the need is ever growing to handle and manage efficiently these large variety of spatial data. The OGC (Open GIS Consortium), an international organization pursuing standardization in the geospatial industry. recently introduced the GMLJP2 (Geographic Mark-Up Language JP2) format which enables store and handle heterogeneous spatial data. The GMLJP2 format, which is based on the JP2 format which is an abbreviation for JPEG2000 wavelet image compression format, takes advantage of the versatility of the GML capabilities to add extra data on top of the compressed image. This study takes a close look into the GMLJP2 format to analyse and exploit its potential to handle and mange hetergeneous spatial data. Aerial image, digital map and LIDAR data were successfully transformed end archived into a single GMLJP2 file. A simple viewing program was made to view the heterogeneous spatial data from this single file.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.54-63
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• 2009

Various methods have been employed for acquiring beach surface data, which are used to monitor shoreline changes due to beach erosion. This study explores the possibility of constructing and implementing a surface model of beach using data acquired with a terrestrial laser scanner and RTK-GPS. Digital images and three-dimensional data of beach areas acquired at 20 cm intervals using a laser scanner were used to create a digital surface model covered with digital image. Seven months later, the beach area was surveyed using an RTK-GPS, and another beach model was constructed using the data collected with an accuracy of 1.9 cm. The use of a terrestrial laser scanner is expected to ensure acquisition of good quality results and help deal with seasonal changes in beach areas. Because readings obtained with the RTK-GPS are dependent on the number of sampling points in beach model, difficulties are encountered when fixing the survey points. However, RTK-GPS could be used to implement a three-dimensional model by correcting the hidden parts in images obtained using a terrestrial laser scanner. Therefore, an RTK-GPS and a terrestrial laser scanner can be used in combination to obtain more precise data for the construction of beach model data.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.139-149
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• 2008

A load effect by vehicles running on a road and an increase of traffic is distinguished as a serious issue in the level of bridges' maintenance and management since it causes a quick damage of bridges. The expansion joint is the most important since it makes vehicles' traveling amicable and stress or additional load harmful to molding patterns minimized. However, it is very difficult to measure its expansion length since vehicles continue to pass on the expansion joint. Therefore, the study could see that it was possible to carry out a qualitative and quantitative maintenance and management if its expansion length is extracted with images. The study could acquire three dimensional coordinates of expansion joints with images. As the results of calculating RMSE of check point residual at 32 points in A area and at 28 points in B area, both A and B areas had very good results of RMSEsms 0.829mm~1.680mm. As the results of analyzing expansion length and immediate value extracted by images, the study analyzed that RMSE of A area was 0.64mm and RMSE of B area was 0.28. The average residual of A area was 0.60% and the average rresidual of B area was 0.27%. Therefore, it is judged that it is more scientific and efficient than the past to measure expansion length with images at the time of repairing and managing bridges in the future.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.4 s.31
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• pp.45-51
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• 2004

Control stations managed by national and local governmes are associated with other survey work and constructing geography information and they are important assets in the national level as the positional standard of the country. Since these control points are managed as some type of register and the control points could not be easily updated due to the loss of control stations from construction work or urban development. Therefore, the users could not understand the present situation of the changed control stations. In this background, the aim of this study was to develop control station management system which the managers can use to efficiently maintain control points and to support the usage of the survey control points. For developing this system, we have designed input, update, network, analysis and statistic functions, and have constructed the system using Mapobject as main engine with other languages such as Visual C++ and Visual Basic. The graphic data used in this system are 1/5,000 digital map and digital cadastral map, and the attribute data of each control station are point name, map tile name, longitude and latitude coordinates, TM coordinates, surveying data with the format of year-month-day and control situation photos and so on. In the result of constructing this control station management system, we could achieve integrated management of graphic, attribute and positioning information of each control station.

• Korean Journal of Remote Sensing
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• v.24 no.2
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• pp.141-152
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• 2008

The 3D building modeling is one of crucial components in constructing 3D geospatial information. The existing methods for 3D building modeling depend mainly on manual photogrammetric processes, which indeed take great amount of time and efforts. In recent years, many researches on 3D building modeling using aerial LiDAR data have been actively performed to aim at overcoming the limitations of existing 3D building modeling methods. Either techniques with interpolated grid data or data fusion with digital map and images have been investigated in most of existing researches on 3D building modeling with aerial LiDAR data. The paper proposed a method of 3D building modeling with LiDAR data only. Firstly, octree-based segmentation is applied recursively to LiDAR data classified as buildings in 3D space until there are no more LiDAR points to be segmented. Once octree-based segmentation is completed, each segmented patch is thereafter merged together based on its geometric spatial characteristics. Secondly, building model components are created with merged patches. Finally, a 3D building model is generated and composed with building model components. The experimental results with real LiDAR data showed that the proposed method was capable of modeling various types of 3D buildings.

• Journal of Digital Convergence
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• v.17 no.11
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• pp.189-194
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• 2019

Forest investigation is the basic data for forest preservation and forest resource development, and periodical data acquisition and management have been performed. However, most of the current forest investigations in Korea are surveys to grasp the current status of forests, and various applications have not been made as geospatial information. In this study, the unmanned aerial scanner was used to acquire and process data in the forest area and to present an efficient forest survey method through analysis of the results. Unmanned aerial scanners can extract ground below vegetation, effectively creating DEM for forest management. It can be used as geospatial information for forest investigation and management by generating accurate topographical data that is impossible in conventional photogrammetry. It can also be used to measure distances between power lines and vegetation or manage transmission lines in forest areas. The accurate vertical distance measurement for vegetation surveys can greatly improve the accuracy of labor measurement and work efficiency compared to conventional methods. In the future, the use of unmanned aerial scanners will improve the data acquisition efficiency in forest areas, and will contribute to improved accuracy and economic feasibility compared to conventional methods.