• Journal of Korean Society for Geospatial Information Science
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• v.4 no.2 s.8
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• pp.47-54
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• 1996

It needs more than two images which are obtained in real time to decide 3D positioning of dynamic object. Though we use digital camera which is became wide utilization, but it can't obtain sequential image. So, in this study, we constructed momentary image acquisition system using video camera. Also, we took a photograph of LCD timer and dynamic object together for real time stereo image, and we obtained independent digital image from sequential image using video editor. As a result of the study, we could obtain the independent image as true color digital image of $788{\times}550$pixels with 1/100sec accuracy in the same time. And it was good when we tested object target. For comparing 3D positioning accuracy, we could obtained negative with metric camera using B-shutter.

• Geophysics and Geophysical Exploration
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• v.1 no.3
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• pp.155-160
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• 1998

EM tomography technique has been developed. The algorithm used the extended Born approximations for forward modeling and reconstructed a conductivity image by a smoothness constraint least squares inversion method. Observed data, the vertical components of secondary magnetic fields, were simulated with the 3-D integral equation code. The results showed that the location of anomalous body could be imaged very well, but conductivity of the body was lower than real one and the vertical resolution was much higher than the horizontal resolution.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.3
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• pp.207-213
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• 2007

For several years, although the demand of high accuracy kinematic positing using multiple bases has been increased, most of the commercial GPS processing softwares can provide the single-baseline solutions only. Thus, we studied the methods to improve the accuracy of the kinematic positioning using the network configuration based on the several single-baseline solutions. As discussed in this study, the positioning accuracy as well as the network stability is improved by introducing the geodetic network adjustment theories into the kinematic positioning application. Three different methods to remove the rank-deficiency, RLESS, BLIMPBE and SCLESS, are analyzed in this study. The 3D RMS error has been improved from 3.5cm(max) to 2.1cm using the network-based kinematic positioning, and it is desired to choose BLIMPBE and SCLESS depending on the accuracy of the base stations.

• Journal of IKEEE
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• v.22 no.3
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• pp.638-644
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• 2018

In this paper, we develop a measurement system that uses 3D Scintillator and NaI(TI) Detector to 3-dimensionally identify the location of multiple radiation sources in moving vehicle loads. The radiation measurement system consists of radiation measurement (plastic scintillator), 2-channel Pulse Counter Board, nuclide analysis (NaI(TI) detector) and 1 channel MCA Board. The source locator algorithm calculates the coordinate value of the ratio of the CPS value($1/r^2$) of the source according to the angle(${\theta}$) in inverse proportion to the square of the distance(X, Y) through the SVM classification. The coordinate values are input every predetermined period of the spectrum, and after analyzing the spectrum per unit cycle, the position of the nuclide at the time is calculated by determining whether or not the nuclide is present in the remaining part except for the background area. As a result of the position discrimination test, the error within the international standard of ${\pm}1m$ was shown. Thus, the utility of the proposed system has been demonstrated.

• 한국지형공간정보학회:학술대회논문집
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• 2002.03a
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• pp.23-26
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• 2002

시설물 관리 시스템 또는 GIS의 구축에 있어서 도형 정보는 주로 대상물의 2차원 평면 형상과 위치 정보로 구성되어 있다. 따라서 대상물의 실제 형상적 특성과 주변 환경과의 관계를 입체적으로 규명하기 위해서는 3차원 정보가 필요하다. 3차원 정보는 점, 선, 면으로 구성되는 기존 공간 데이터의 경직성을 탈피하고 현실적 세계를 표현할 수 있는 장점이 있다. 특히 기존의 측정 개념으로 접근 할 수 없는 영역에 대한 정보를 획득할 수 있으며, 복잡하고 다양한 형태의 대상물에 대한 정보의 획득이 용이하다. 본 연구에서는 실험적으로 3D 레이저 스캐닝 시스템을 적용하여 공간 데이터를 획득하고 데이터의 특성을 분석하였으며, point cloud 데이터의 처리 및 관리 시스템과의 연계 방안을 제시하고자 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1953-1956
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• 2008

본 연구에서는 금강의 하류부의 시간적 공간적 수질변화를 자세하게 분석하기 위하여 3차원 수리동역학 모델인 EFDC 와 비정상상태 수질모델인 WASP 7.2와 를 연계 적용하였다. 본 연구의 대상 구간은 금강하류 부중 대청댐 조절지 방류구 지점부터 공주의 정안천 유입 직전까지 총 48km의 구간이다. 하천의 수심별 수질은 일정하다고 가정하였으나 폭방향의 수질은 좌 중 우로 3개의 소구간으로 나누고 하천의 흐름 방향으로 나누어 전체적으로는 2차원적으로 구분하였다. 하천의 바닥 형상을 이용하여 모델 격자를 구성하였으며 수리모델은 건교부의 수위자료를 이용하여 보정하였고 수질자료는 환경부의 수질측정망 자료를 이용하여 보정하였다. 2차원 수리동역학-수질 연계모델링 결과, 대전 갑천이 유입되고 난 후의 청원지점에서 그리고 청주지역의 영향을 포함하는 미호천이 유입되고 난 연기 지점 그리고 본 연구의 최하류인 공주지점에서는 하천의 폭 방향으로 상당한 수질 차이가 있음을 확인하였다. 이는 대전 갑천 또는 청주 미호천 등이 유입된 이후 효과적으로 혼합되지 않는다는 것을 의미한다. 이는 해당지역의 수질시료 채취 위치에 따라 수질에 현격한 차이가 있을 수 있다는 것을 나타내며, 현재 환경부 수동측정망의 시료채취 방법을 고려하여 볼때 하천수질의 대표성을 나타낼 수 있는가 하는 문제의 차원에서 매우 심각하게 받아들여져야 할 것으로 생각된다. 한편, 현재 우리나라에서 시행되고 있는 오염총량관리제나 대부분의 환경영향평가에서는 하천의 폭 방향의 수질 차이에 대한 고려가 전무하며 이에 대한 전면적인 재검토가 시급하다고 판단된다.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.2 s.8
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• pp.161-172
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• 1996

The objective of this research is to develope a process of integrating video image into digital map. In order to reach the research objective, the work includes the development of georeferencing technique for video images, the development of pilot system and the assesment process. Georeferencing technique for video images is composed of DGPS positioning, filtering of abnormal points, map conflation, indexing locations for key frames via time tag and indexing locations for total frames. By using the proposed building process, we could find the result that the accuracy of image capturing test points is $92.8%({\pm}2\;frames)$. The eventual meaning of this study is that it is possible to find a new conception of digital map, which overcomes a limitation of exiting two dimensional digital map.

• Journal of Broadcast Engineering
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• v.19 no.2
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• pp.215-226
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• 2014

The 3D technology has been spread slowly and the reason would be attributed to the fact that most commercialized 3D displays require 3D glasses. There have been various researches on human factors of glass type 3D display. In this study we measured and modeled crosstalk as well as 3D visual fatigue induced by mobile glassless 3D display. Crosstalk as well as visual fatigue varied depending on horizontal position of the 3D mobile display. Measured crosstalk was relative low around the center of the display and it increased at the side of the display. Similar results were found in the measurement of 3D visual fatigue and discomfort. These results imply that human factors should be considered in the process of design and evaluation of mobile 3D displays.

• Journal of Sensor Science and Technology
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• v.6 no.4
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• pp.290-297
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• 1997

In this study, the radiation monitoring system using CsI(TI) scintillation counter is developed for the measurement of radiation distribution in the field of high dose level. When the inner diameter of collimator is 8 mm, we have realized the optimum detecting efficiency and spatial resolution. At that time, the position resolution was 10 cm at 1 m from the system. And experimental results indicated that the energy resolution of the system were 10 % for 662 keV of Cs-137, 7.6 % for 1.17 MeV of Co-60, and 5.8 % for 1.33 MeV of Co-60. Also, we have shown that the real radiation distribution images may be obtained by our measurement system.

• Journal of Korea Water Resources Association
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• v.30 no.5
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• pp.477-485
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• 1997

Recent internal and external bridge failures due to pier and abutment scour have emphasized the need for better methods of scour depth estimation. This paper compares the hydraulic analysis of the Namhan River Bridge over the Namhan River using one-dimensional models. WSPRO & HEC-2, and the two-dimensional model. TABS-MD based on the procedures presented in HEC-18 published by the U.S. FEdral Highway Administration. A comparison of estimated scour depth for this research based on the results from both one-dimensional and two-dimensional model is presented. At the same time, field measurement has been performed before and after flood using sounding instrument. Fathometer (DE-719C). A comparison between estimated and measured scour depth at bridge is also presented. Result shows that there is all the difference between estimated and measured scour depth due to dissimilarity between laboratory and field conditions. Also, it is difficult to measure the maximum scour depth accurately due to refilling. Therefore development of scour measuring equipment which can be used during peak flood, and derivation of empirical model appropriate for internal river system seems urgent.