• 한국지반공학회논문집
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• 제40권3호
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• pp.101-108
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• 2024

터널 공사중 발생 가능한 쐐기블록(Key block)을 막장관찰 중 인지하여 전방으로 형성되는 쐐기블록을 예상하고, 안전율을 확인할 수 있는 시스템을 개발하였다. 막장관찰시, 레이저 스캐너를 이용하여 암반면의 3차원 점군을 수집하고, 이를 근거로 굴착면을 형상화한 후, 암반 절리면을 도출한다. 절리면은 주향과 경사각을 가지고 있으므로, 절리면들의 조합을 통해 형성되는 쐐기블록을 반복 계산을 통해 도출하고, 각 쐐기블록의 안전율을 계산한다. 모형실험을 통해 시스템의 절리면 특성 산출의 정확성을 확인하였고, 절리면 정보를 입력하여 계산되는 기존 상용 소프트웨어의 결과값과 비교하여 개발 프로그램이 오차 1%이내로 계산 결과를 얻을 수 있음을 확인하였다.

• 대한기계학회논문집A
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• 제24권1호
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• pp.173-181
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• 2000

Depending upon the method of the surface generation and the quality of the boundary curves provided, the resulting surfaces may have global or local irregularities in many cases. Thus it would be necessary for the designer to evaluate the surface quality and to modify the surface. This capability is very important because the defect of the surface requires the rework of the dies that causes a big loss in cost and delivery time. To simulate the reflection line test in the actual production line, a faster generation algorithm is presented. Among., various surface interrogation methods using reflection lines, Blinn-Newell type of reflection mapping is applied to generate reflection lines on the trimmed NURBS surface. The generation of reflection lines is formulated as a surface-plane intersection problem, and solved by surface-contouring techniques. In addition, a modified reflection map is proposed to eliminate the discontinuity of reflection lines due to the configuration of the reflection map. A fast reflection line algorithm is developed utilizing an efficient traced contouring technique, and proved to be well suited for real-time quality-assessment task.

• 자원환경지질
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• 제38권4호
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• pp.369-380
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• 2005

영상을 기반으로 한 불연속면의 방향성 측정 및 거칠기 평가에 대한 효율적이고 객관적인 기법의 적용 가능성을 제시하는데 본 연구의 목적이 있다. 현장조사 및 계측을 통한 암반사면 안정성 평가의 한계를 보완하기 위해 디지털 영상으로부터 3차원 수치 암반사면모델을 생성하여 암반사면에 대한 지형 공간적 분석을 위한 기초 정보를 도출하였다. 또한, 암반사면 내에 분포한 불연속선을 3차원적으로 추출하여 불연속면의 집중 방향성을 분석하고, 암반표면의 거칠기를 정량화할 수 있는 방법을 제시하였다. 연구결과 입체 디지털 영상으로부터 암반사면에 대한 다양한 정량적 정성적 분석이 가능한 정보를 효과적으로 추출할 수 있었으며, 이를 시각화하여 안정성 평가의 효율성과 편의성을 향상 시킬 수 있었다.

• Journal of Mechanical Science and Technology
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• 제15권2호
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• pp.160-171
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• 2001

Depending upon the method of the surface generation and the quality of the designed boundary curves, the resulting surfaces may have global or local irregularities in many cases. Thus, it would be necessary for the designer to evaluate the surface quality and to modify the surface. This is very important because the defect of the surface causes the rework of the dies, increasing cost and delivery time significantly. To simulate the reflection line test in the actual production line, a faster algorithm for generating reflection lines is presented. In this paper, among various surface interrogation methods using reflection lines, Blinn-Newell type of reflection mapping is applied to generate the reflection lines on the trimmed NURBS surfaces. The derivation of reflection lines is formulated as a surface-plane intersection problem (Jung 1994) and is solved by surface-contouring techniques. Also, for eliminating the discontinuity of reflection lines due to the configuration of reflection map, a modified reflection map is proposed. An efficient traced contouring technique is utilized for the computational efficiency and proves to be well suited for the real-time quality-assessment task.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 춘계학술발표회논문집
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• pp.203-208
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• 2004

Recently, digital image is increasing greatly practical use degree in several industry fields including construction. And interest about 3D digital image that can express practical object realistically is augmented greatly. In this study, developed 3D digital image generation system based on digital photogrammetry and created 3D digital image for object. And, wished to verify of 3D digital image through comparative analysis with processing result by digital photogrammetry system been using much the latest for acquisition of 3D information. Also, wished to apply to surface information acquisition about rock slope and execute investigation about discontinuity of joint etc. As the result, could created 3D digital image for object using the 3D digital image generation system developing in this study, and acquire surface information about rock slope efficiently.

• 한국재난관리표준학회지
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• 제2권2호
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• pp.75-83
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• 2009

암반사면에 대한 표면조사 시에는, 암반 사면파괴로 인한 재해의 원인이 될 수 있는 파쇄대에서의 응력이완, 노출되지 않은 불연속면 등의 요인들을 고려하지 못하는 한계가 있다. 이에 본 고에서는 사면의 절취 또는 절취사면의 유지관리에 있어서 사면 안정성에 대한 판단을 도와 사면 파괴로 인한 재해를 예방하는 방안을 제시하고자 한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1500-1503
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• 2004

Errors resulting from magnification variations of optical system are largely generated in three-dimensional shape measurements. In the case of measuring the surface morphology of tiny objects based on DFF, images are acquired with a very small interval and then magnification changes are minimized. However, the magnification variations are actually existed in optical system and so focus measures in DFF are wrongly or ambiguously extracted. in this paper, a methodology based on DFF with the magnification changes is proposed to make more accurate measurement in surface morphology with high depth discontinuity, compared with previous ones. Several experiments show that the proposed method outperforms existing ones without magnification changes.

• 제어로봇시스템학회논문지
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• 제1권2호
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• pp.105-111
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• 1995

This paper proposes a segmentation algorithm using gray-level discontinuity and surface reflectance ratio of input images obtained under different illumination conditions. Each image is divided by a certain number of subregions based on the thresholds. The thresholds are determined using the histogram of fusion image which is obtained by ANDing the multiple input images. The subregions of images are projected on the eigenspace where their bases are the major eigenvectors of image matrix. Points in the eigenspace are classified into two clusters. Images associated with the bigger cluster are fused by revised ANDing to form a combined edge image. Missing edges are detected using surface reflectance ration and chain code. The proposed algorithm obtains more accurate edge information and allows to more efficiently recognize the environment under various illumination conditions.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.299-304
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• 1988

This paper describes the application of the variable structure control(VSC) concept for the position control of electro-hydraulic servomtor system. The basic philosopy of VSC is that the structure of the feedback control is altered as the state crosses discontinuity surfaces in the state surface with the result that certain desirable properties are achieved. The switching of the control function yields total(or selective) invariance to system parameter variations and disturbances, and closed loop eigen value placement in time-varing and uncertain systems.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.526-528
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• 2003

There are some reports which are about measuring the discontinuity from 3D model of rock surface. To generate 3D model is mainly based on remote sensing technique like laser scanning and digital stereo photogrammetry. It is obtained the DEM of the rock slope using above techniques in this study, and examined a suitability and improvement of the photogrammetry for the rock slope by overlap the DEM. It seems that accuracy of DEM generated by photogrammetry technique is influenced by the geometry of rock and type of joint.