• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.292-295
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• 2007

개발계획이나 환경계획 수립시에 절대적인 해발고도를 기준으로 지형적 특성을 분석한다면 절대표고가 낮은 지역은 대부분 개발가능지로 구분된다. 따라서 지역적 특성을 반영하는 상대표고를 적용하여야 하나 산의 경계구획，능선설정 등의 어려움으로 아직 전국단위의 구체적인 연구는 미흡한 실정이다. 이에 본 연구에서는 최근 Weiss 가 제안한 지형위치지수 ( Topogr aph i c Position Index, TPI) 를 적용하여 전국 단위의 상대표고 분석 가능성을 검토하였다. TPI 모델 도출 결과와 기존 환경부 국토환경성 평가에 사용한 Gaia EZeye 모델 결과를 중첩 비교한 결과 정확도가 높은 것으로 나타났다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.04a
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• pp.252-257
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• 1995

전자기력을 이용한 능동 진동제어는 1979년 Ellis 및 Mote가 원형 톱의 횡 진동의 감쇠에 관한 연구를 수행하였고, 1990년 Hong Su 및 T.S.Sankar등은 시스템의 절대 위치, 절대 속도 및 상대 위치 등의 제어 변수에 대하여 전자기 액튜에이터의 동적 특성이 진동 절연 성능에 미치는 영향에 관한 연구를 하였다. 본 연구는 상부질량과 하부질량이 스프링으로 연결된 2자유도 모델의 능동 진동제어에 대하여 이론해석과 실험해석을 수행하고 각각의 결과를 비교하였다. 실험모델은 직선운동 가이드에 설치된 2개의 질량과 하나의 전자기 액튜에이터를 이용하였다. 진동제어 방법으로서는 모우드 해석에 의한 제어, 스카이 훅 감쇠 제어, Viscous damping 제어 방법을 적용하였다. 본 연구의 목적은 이론해석 결과와 실험 결과를 비교하고 비슷한 제어효과에 대해서 에너지 소비가 작은 효율적인 제어방법을 찾는데 있다.

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.244-245
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• 2005

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.25-26
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• 2006

The method measuring the absolute position of a point diffraction source emitting a spherical wavefront in three-dimension is proposed. Two-dimensional interference of spherical wavefronts is used to overcome ambiguity of phase order. The spherical wavefront is explicated by Taylor series expansion, from which a radius of curvature of a spherical wavefront and its center position in three-dimension are obtainable. The spherical wavefront is reconstructed by a modified lateral shearing interferometer, which uses single-mode fiber as a point diffraction source.

• The Journal of Engineering Geology
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• v.17 no.4
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• pp.567-576
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• 2007

In order to assess the on-site applicability of 3D absolute displacement monitoring of tunnel using digital photogrammetry, the displacement of the optical target placed at the measurement section was investigated, as planned in the OO tunnel construction site. The targets on 3 measurement lines only were considered for each point of measurement for the reconstruction of 3D cubic model for the digital vision monitoring. For each 3D model, 3 or more images have to be obtained at each point. On the last 2 measurement lines, 6 targets (crown, left and right walls) were continuously overlapped to construct 3D models so that 6 or more apices can be shared by 2 3D models. In order to compare the measurement methods of 3D absolute displacements in tunnel excavation, i. e, total station and digital image measurement, both the digital image measurement and optical measurement were conducted for 10 times in the same work section. The time and measurement results of both methods were compared.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.1
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• pp.9-15
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• 1998

Numerical cadastral surveying method has advantages of higher accuracy and less individual error than planetable surveying method if we consider the result of surveying at the same area. Now in the areas where they use numerical cadastral records, coordinate is the basis when the boundary location is registered in numerical cadastral re-cords or is reconstructed on land surface, and this coordinate represents simply the absolute locational relationship with respect to origin point. But when we register the cadastral boundary location in cadastral or reconstruct it on land, relative relationship with respect to traverse point is more advisable basis than absolute relationship with respect to orgin point. This study contributes to the numerical cadastral surveying by discussing the problems to be improved that the principle of coordinate based boundary location registration and reconstruction has.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.04a
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• pp.264-269
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• 1995

유연계의 제어기 설계를 위한 구동기의 최적 위치 선정법이 제시되었다. 위치 후보의 적합성을 파악하기 위해 초기 외란의 조정에 필요한 최소 입력 에너지와 관련된 모드 가제어도가 정의 되었는데 이는 구동기를 모든 후보 위치에 설치한 이상적 제어기의 성능에 대한 특정 후보 위치의 상대적 성능을 나타낸다. 모드 가제어도로 구성된 목적 함수를 이용해 구동기를 위한 최적 위치의 선정이 가능하였으며, 목적 함수의 절대적 크기를 통해 사용된 구동기의 수의 적절성 역시 파악할 수 있었다. 또한, 시스템 규명을 위한 가진기의 위치 선정 방법이 제시되었으며, 이를 위해 모드 가제어도에 상대되는 모드 가진도가 정의 되었다. 모드 가진도는 정상 상태에서의 특정 모드로의 입력 에너지의 통계적 분포를 나타낸다. 수학적 유도 과정을 통해 제어 시간이 충분히 큰 경우 모드 가제어도가 모드 가진도로 수렴해 감을 보였으며, 이로부터 제어시간이 충분한 경우, 최적의 구동기 위치는 최적의 가진기 위치로도 사용될 수 있음을 보였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.5
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• pp.477-484
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• 2012

Recently, as earthquake is more frequently taking place around the world due to diastrophism, the importance of diastrophism and disaster detection is becoming more important. In this study, to analyze the interpretation of seismic displacement by the Japanese earthquake in March, 2011, and monitor the diastrophism of plates in Japan and surrounding Eurasia, Pacific, and Philippines before and after the earthquake, the observational data from IGS observatories in Japan and Asian regions were processed by precise point positioning. The displacement was biggest in MIZU, which was the closest to the epicenter, and the earthquake-affected region was in inverse proportion to the distance from the epicenter. The result of calculating the diastrophism speed before and after the earthquake, based on precise point positioning of IGS observatories located in the 4 plates around Japan, showed that the displacement speed changed and different plates showed different results. The comparison with the plate fate model allowed to analyze the change in diastrophism by earthquake, and to understand the characteristics of the displacement of the plates around Japan. Later, a continuous diastrophism monitoring based on GPS is needed for earthquake prediction and diastrophism research, and the data gained by continuous GPS-based monitoring of diastrophism will be fully used as basic data for relevant research and earthquake disaster management.

• Journal of the Korean Geographical Society
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• v.43 no.3
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• pp.432-447
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• 2008

This study is to examine and analyze the the connection types between location knowledge and understanding the characteristics of world regions which 8th grade students are recognizing. In the analysis of the relation between the location knowledge and region understanding(clothing, food, housing and living style and so on), I analyzed the relation types between location knowledge and region living figures. Absolutely understanding the region needed the efact location knowledge on the world map, the knowledge of the longitude and latitude, symbolic area and the higher ranking region and the information about natural surroundings in which I grasp the region living figures. In addition, it needed the knowledge of locational attributes for the connection formation between region location knowledge on maps and understanding the region. The relative location knowledge related to the other regions and those natural surroundings and the linkage of those region locational attributes are needed in order that the location knowledge on a map could be connected to the knowledge about the actual region living figures. So I call it 'the structured location knowledge'. In order to form the structured location knowledge, the location knowledge of region on a map have to be connected to the multiple knowledge about absolute and relative locations with the knowledge of diverse location attributes. Therefore, it would be necessary that the location teaming for getting the characteristics of region have to be systematically accomplished departments of location-climate$^{\circ}{\mathbb{S}}$geographical features-region living figures.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.1
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• pp.9-17
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• 2001

GPS is an efficient system in surveying and car navigation. but it is difficult to catch minimum number of satellite when it is hindered by obstacle such as city area. GLONASS system doesn't have perfect constellation yet, but it has many similarities with GPS system in principle of point positioning and signal system. so, it is expected to be much efficient when it is used with GPS system. For the purpose of this, the coordinates of GPS and GLONASS system, the quality of time and frequency was investigated, and the algorithm of point positioning was made. also, the efficiency of GPS/GLONASS combination was presented by analysing the precision of 3D point positioning using C/A code and Yuma satellite orbit information.