• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1476-1481
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• 2009

최근 기상이변과 국지성 호우로 인한 홍수피해를 경감하기 위해 국가차원과 더불어 지역단위의 홍수방어대책이 많은 사업을 통해 제시되고 있다. 대표적인 예로 풍수해저감종합계획과 하천기본계획 등을 들 수 있는데 이러한 사업들은 실제 피해지역에 대한 원인과 대책을 제시함과 동시에 홍수 등의 피해가 예상되는 위험지역에 대해서도 그 원인과 대책을 제시해야한다. 따라서 피해발생이 예상되는 지역을 예측하고 그 원인을 찾는데 있어 최근 홍수범람해석에 대한 필요성이 점차적으로 증대되면서 다양한 해석모형과 프로그램들이 개발되었고 현재까지도 홍수범람분석에 관한 활발한 연구들이 이루어지고 있다. 그러나 홍수범람구역을 결정하기 위한 과정은 GIS Tool에 대한 이해도 부족, 원 자료의 부족, 지형 구축을 위한 자료생성의 어려움 등과 같은 다양한 문제점들을 내포하고 있다. 특히, 홍수범람구역의 결정을 위한 전산프로 그램의 기능향상은 점차 향상되는데 비해 지형구축 등과 같은 범람해석 프로세스 내에서 상당한 수작업이 요구되는 바 작업소요시간이 많이 요구되는 단점으로 인해 실무자들에게 널리 적용되는데 있어 걸림돌이 되고 있는 실정이다. 따라서 본 연구에서는 실무적 관점에서 홍수범람해석의 요구빈도가 높은 중소규모 자연하천을 대상으로 두가지 해석 기법을 통하여 홍수범람해석을 수행하여 해석 과정 및 결과 등을 비교하였다. 첫 번째 기법으로 홍수범람해석을 수행하는데 있어 실용성, 신속성 등이 고려된다고 판단되는 Civil 3D를 이용하여 수치지형도 및 측량자료와 같은 원 자료로부터 3D 지형을 구축하고 Civil 3D의 Extension 프로그램인 HEC-RAS Tool과 1차원 수리모형인 HEC-RAS를 전 후처리에 연계함으로서 각 대상유역별, 빈도별 홍수위에 따른 홍수범람구역과 수심 및 범람지역을 우선적으로 분석하였다. 두 번째 기법으로서 실무에서 주로 이용되고 있는 ArcGIS를 이용하여 3D 지형을 구축하고 Hydrologic Engineering Center (HEC)와 Environmental Systems Research Institute(ESRI)의 협력개발로 개발된 HEC-GeoRAS와 HEC-RAS 모형을 전 후처리에 연계하여 홍수범람해석을 수행하였다. 이들 두 가지 기법을 통한 홍수범람해석의 과정과 결과에 대해 정량적, 정성적 비교를 수행하였으며, 두 기법간의 차이점 및 효율성을 제시하였다. 본 연구의 결과는 보다 실용적이면서도 정밀한 홍수범람구역의 결정, 홍수범람 예상도 등의 재해지도 작성, 치수경제성 분석 등에 있어 도움이 될 것으로 판단된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2481-2486
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• 2013

It requires a lot of time and effort for general users who do not have enough understanding of GPS to properly processing GPS data. However, the GPS data processing field heavily relies on foreign-produced software and there is almost no development of user-oriented technology. Therefore, in this study, it was attempted to build an expert service that enables non-experts to use high-precision GPS data processing. As a result, an expert service that can maximize user convenience simply by entering the minimum required information for GPS data processing was developed, and the expert service was verified by relative positioning processing of the observation data of satellite control point provided by National Geographic Information Institute and observation data obtained by GPS survey. The expert service significantly reduces the effort and time for processing GPS data, which will contribute to precise positioning and other various studies.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.485-487
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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 topographical 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 Cadastre & Land InformatiX
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• v.47 no.1
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• pp.179-190
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• 2017

A terrestrial LiDAR survey was conducted and unmanned aerial vehicle(UAV) images were taken for target cultural properties to present the utilization measures of terrestrial LiDAR and UAV in three-dimensional modeling of cultural properties for the identification of the status and restoration of cultural properties. Then the accuracy of the point clouds generated through this process was compared, an overlap analysis of the 3D model was conducted, and a convergence model was created. According to the results, the modeling with terrestrial LiDAR is more appropriate for precise survey because 3D modeling for the detection of displacement and deformation of cultural properties requires an accuracy of mm units. And UAV model has limitation as the impossibility of detailed expression of parts with sharp unevenness such as cracks of bricks. However, it is found that the UAV model has a wide range of modeling and has the advantage of modeling of real cultural properties. Finally, the convergence model created in this study using the advantages of the terrestrial LiDAR model and the UAV model could be efficiently utilized for the basic data development of cultural properties.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.3
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• pp.22-30
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• 2007

It is difficult to generate DTM using aerial photographs because trees usually cover disaster occurred areas. So, this study proposed how to filter by moving window using digital aerial photographs and generate accurate DTM. The results were compared with those of adaptive filtering by commercial digital photogrammetry software (Socet set) to find out the effect of tree removal by window size in forest soil sediment disaster. And then they were compared with DTM generated from LiDAR data. As a result, it was showed that the accuracy of moving filtering DTM was lower than that of LiDAR DTM while it was higher by 6m than that of Adaptive filtering.

• 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.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.3
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• pp.148-156
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• 2002

The coastline of Hampyung Bay, southwestern coast of Korea, was examined and measured in the field for the understanding of geomorphic changes and sea-cliff erosion processes. The Hampyung-Bay coastline is characterized by steep-face slope and soft soil and/or intensively weathered rock composition. Saw teeth-shaped coastline, and relict weathered basement-rock and "Island Stack" exposed on the beach surface are peculiar geomorphic features indicating active sea-cliff erosion. The coastline in the study area is continuously retreating with the following cyclic process: erosion of cliff base, gravitational landslide or mass wasting, formation of talus, and then erosion and removal of talus. In this study, sea-level rise during summer in the west coast of Korea is suggested as one of the key factors fur the removal of soil taluses and, thereby, accelerating sea-cliff erosion.f erosion.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.3
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• pp.73-83
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• 1988

This paper aimes to study a refraction errors developed in the inclined leveling route. Based on Kukkamaki's theory and morden meteorology, the author devised an experiment to test how Kukkamaki's corrections was improved the discrepancy between fore and back leveling in actual slope. Additionally, through the repeated observation between fore and back leveling at one fixed station in the slope and experimental test of continuous inclined leveling route, the author studied the effects of refraction and its characteristics. We carried out leveling and temperature measurements in the continuous inclined leveling route of about 1.5km, and consequently, Kukkamaki's refraction correction values using these respective C=-0.1 and -1/3 values could improve the similar discrepancy.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.3 s.30
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• pp.51-59
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• 2004

In the study, there has been a sharp upward trend in road maintenance cost as the expansion of road networks increases. Running a pavement management system(PMS) is indispensable for efficient and scientific maintenance of the whole road networks with limited maintenance budgets. With a PMS, a maintenance plan should be drawn up after surface conditions are precisely examined and analyzed. The majority of the present PMSs are run by the fact that experts first examine surface conditions on sites, and then enter results into systems. However, considering the actual circumstances of the present time and the increase in paved road hereafter, it is inefficient that experts examine the whole paved roads in person and long-lasting PMSs can not be kept up. As a result, after analyzing the accuracy of 3-D coordinates representing road surfaces that was decided using multi orientation and digital photogrammetry, the average of standard errors turned out to be 0.0427m on the X-axis, 0.0527m on the Y-axis and 0.1539m on the Z-axis. It was found to be good enough to be put to practical use for maps drawn on scales below 1 :1000, which are being currently made and used within the country, and GIS data.

• Journal of Advanced Navigation Technology
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• v.18 no.6
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• pp.555-561
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• 2014

Data processing service via internet help user to get the GNSS data processing result more precise and easily. Thus, online data process system is operated and developed by various research groups and national. But this service is difficult to use in domestic cadastral survey. In this study, we developed the online data processing system for a domestic cadastral survey. This is calculated coordinate using NGII CORS(SUWN) fiducially. And use PPP technique by GIPSY-OASIS. If user choose the observation data which want to calculate the coordinate, then is uploaded to GIPSY-OASIS server through FTP. After upload is complete, server automatically calculate coordinate, and send the report about result using e-mail. And it takes 2 minutes runtime on the basis of the 3 sessions. To verify the result, we used the data on SOUL, JUNJ as compared with notified-coordinate from NGII. As a result, got the difference for east-west 1.4 cm, north-south -1.0 cm, vertical 0.5 cm.