• Korean Journal of Cognitive Science
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• v.12 no.4
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• pp.49-56
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• 2001

When multiple features are presented in the image the computational models for stereopsis select the most activated matches through the excitatory and inhibitory interactions among all possible matches. Using the random-dot stereogram with two surfaces. we investigate whether human binocular mechanism selects the most activated matches. The dots consisting a surface lying in a fixation plane were selected randomly while each of the dots consisting the other surface was paired with each of the original dots in the following manner. After finding the position of each dots in the original random pattern we placed an additional dot to the left and to the right of the original position in each of the left and right image of a stereogram respectively. The luminance of additional dots was varied while that of the original random dots was fixed so that the hypothetical matches presumably could be activated differently. Across the luminance condition the depth of each surface was measured to examine whether matches to be selected were changed depending on the activation level of possible matches. When the luminance of two patterns was within 30% of one another observers perceived an opaque surface. Beyond this value two transparent surfaces were seen with the magnitude of perceived depth varying with relative luminance of two patterns. When original pattern was brighter one additional surface was perceived at the depth corresponding to the disparity of original pattern. When original dot was dimmer. however the depth of an additional surface corresponded to the disparity of newly introduced pattern. These results suggest that there are dynamic interactions within the matching process whereby highly activated matches inhibit weaker one.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.06a
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• pp.105-106
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• 2018

본 논문에서는 동적 프로젝션 맵핑을 구현하기 위하여 3차원 공간의 깊이 정보와 대상 객체의 색상영상에서의 특징점을 추출하여 3차원 공간상에서 움직이는 2차원 평면 객체의 자세를 안정적으로 추정하는 기법을 제안한다. 제안 기법은 타겟 이미지를 출력하여 타겟 이미지 보다 큰 평면 패널에 부착하고, 이 평면 패널을 3차원 공간상에서 움직이는 환경에서 타겟 이미지의 자세를 안정적으로 추정하기 위하여 고안되었다. 제안 기법에서는 우선 패널이 움직일 수 있는 깊이 영역을 지정하여 해당 깊이 영역에 존재하는 2차원 패널을 추출하고, 패널의 사각영역을 추출한다. 또한, 색상 영상에 SURF 알고리즘을 적용하여 2차원 평면상에 부착된 타겟 이미지의 영역을 색상 특징을 기반으로 함께 추출하여 패널의 사각 영역과 타겟 이미지의 상대적인 위치 정보를 추출한다. 셋업 단계에서 추출된 타겟 이미지의 상대적인 위치 정보를 이용하여, 조명의 변화에 의하여 순간적으로 타겟 이미지의 특징점 추적에 실패한 경우, 패널의 사각 영역에 의해 계산된 타겟 이미지의 상대적 위치 정보를 계산하여 자세 추정에 사용함으로써 움직이는 타겟 이미지의 3차원 자세를 안정적으로 추정할 수 있도록 하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.6
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• pp.527-532
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• 2013

Depth estimation is an essential factor for robot vision, 3D scene modeling, and motion control. The depth estimation method is based on focusing values calculated in a series of images by a single camera at different distance between lens and object. In this paper, we proposed a relative depth estimation method using focus measure. The proposed method is implemented by focus value calculated for each image obtained at different lens position and then depth is finally estimated by considering relative distance of two patterns. We performed various experiments on the effective focus measures for depth estimation by using various patterns and their usefulness.

• Journal of the Korean Geotechnical Society
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• v.20 no.5
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• pp.127-134
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• 2004

Rammed Aggregate Pier (RAP) has extensive applicability as for a foundation of structures. In this study, bearing capacity of the reinforced ground by RAP and the failure behavior of RAP are investigated through experiments. RAPs with diameters of 45, 60, 70 mm were installed in sand, of which relative densities are 60, 70, 90%. Then, two columns of pressure gauges, near the RAPs and one diameter off from the center of piers, are installed 5, 10, 15, 20, 25, 30 cm from the surface of the ground. The test results show that maximum lateral earth pressure is observed near 5∼10 cm (1.0∼2.0D) from the surface, which indicates the occurrence of bulging failure type. In addition, deformation of RAP in radial direction increases with lower relative density of the ground. Furthermore, lateral stress distribution decreases with depth.

• Journal of the Korean Geotechnical Society
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• v.16 no.6
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• pp.5-13
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• 2000

모래지반의 상대밀도, 말뚝의 시공방법, 일정근입깊이에 따른 소요향타 에너지 그리고 지하수 조건에 따라 말뚝의 지지력과 하중전이를 연구하기 위하여 강관말뚝을 이용한 모형실험을 수행하였다. 매입말뚝은 말뚝을 미리 설치한후에 지반성형을 실시하였고, 타입말뚝은 매입말뚝과 같은 깊이까지 항타높이를 5, 10, 15cm로 달리하여 말뚝을 관입하였다. 그 뒤 정적하중을 단계적으로 가하여 하중-침하 곡선에 의한 모형 말뚝의 지지력과ㅏ 말뚝내의 등간격으로 설치된 변형 게이지를 이용하여 타입말뚝 의 하중전이에 대해 살펴보았다. 타입말뚝의 하중전이시험에서는 항타 전과 항타 후 말뚝내 하중전의 소효항타 에너지에 따른 변화를 관찰하였다. 매입말뚝의 시험결과는 현재 가장 많이 사용하고 있는 대표적인 정적 지지력 공식들에 의하여 계산되어진 값들과 비교 분석하였다. 그 결과 상대밀도가 작은 느슨한모래지반에서는 Vesic 공식이 그리고 상대밀도가 큰 조밀한 모래지반에서는 Hanbu 공식이 가장 근접한 평가를 나타내었다. 하중전이시험에 의한 항타시 잔류응력은 모든 경우에서 지표면과 선단부위에서 아주 큰 잔류응력이 나타났고. 말뚝의 선단 지지력비는 상대밀도에 비례하게 증가하였다.

• Progress in Medical Physics
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• v.15 no.1
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• pp.39-44
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• 2004

The energy distributions for clinically used electron beams from measured and calculated mono energetic depth dose values were calculated. The energy distributions having the minimum difference between the measured and reduced values of depth dose are determined by iterations based on least square method. The nominal energies of 6, 9, 12, 15 MeV clinical electron beams were examined. The Monte Carlo depth dose calculations with determined energy distributions were peformed to evaluate those distributions. In a comparison of the calculated and measured depth dose data, the standard errors are estimated within $\pm$ 3% from surface to R$_{80}$ depth and within $\pm$4% from the surface to near the range for all electron beams. This can be practically applied to determine the energy distributions for clinically used electron beams.

• Korean Journal of Cognitive Science
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• v.14 no.3
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• pp.37-49
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• 2003

Most 3D display systems heavily depend on binocular disparity to produce 3-dimensional depth of a scene. In principle, the vergence angle of the object on fixation and binocular disparity of non-fixated objects vary with the inter-pupillary distance(IPD) of the observer. However, most stereo systems provide the identical stereo image pairs regardless of the observers' IPD, which may result in variation in the perceived depth. In this study, we manipulated the vergence angle of the fixated object and binocular disparity of the non-fixated object. The range of the individual difference in the perceived depth was found to be increased with the increase of disparity for both the fixated and non-fixated objects, and the individual difference was well fitted by the regression line of the observers' IPD. These results suggest that individual difference in the perceived depth from the identical stereo images should be greatly reduced if the stereo system calibrates the disparity of the object by the observers' IPD in generating the stereo images and the regression line found in this study might be useful in the calibrating the disparity of the images.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.279-279
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• 2013

차세대 태양전지로 주목받는 화합물 박막 태양전지(CIGS, CdTe, etc)는 광흡수계수가 매우 높아 얇은 두께의 광흡수층으로도 빛을 효과적으로 흡수할 수 있으므로 광흡수층의 역할이 매우 중요하며 이에 대한 정확한 정보와 이해는 필수적이다. 특히 GIGS 박막 태양전지의 정량 및 각 원소의 깊이 방향의 분포를 분석하는 것은 박막형 태양전지 개발에 크게 기여한다 [1,2]. 본 실험에서는 조성비를 알고 있는 균질한 CIGS박막을 표준시료로 사용하여 ICP-MS로 측정하여 평균농도를 구한 뒤 TOF-SIMS, D-SIMS, Auger Electron Spectroscopy (AES) 로 깊이 방향 분석 결과를 통해 상대감도(RSF)를 계산한 후 각 원소의 농도로 변환하여 정량분석 결과를 얻었다. 일반적으로 손쉽게 정량적인 정보를 얻는 AES에 비해 정량성이 떨어지는 TOF-SIMS와 D-SIMS는 스퍼터링시 사용되는 Cs 빔과 시료 내 금속과의 클러스터 이온(GaCs+와 InCs+)의 깊이 방향 조성을 이용하면 매트릭스 효과를 배제할 수 있어서 좀 더 정확한 정량 분석이 가능하므로 시료내 금속과 Cs 이 결합된 클러스터 이온의 깊이 방향 조성을 측정하여 각원소의 농도를 계산하였고 스퍼터링 에너지를 포함한 실험 변수에 따른 재현성 및 정량성의 차이를 비교분석하였다. 또한 CIGS층에 불순물로 들어 있는 미량원소들의 깊이 분포도도 함께 관찰하였다.

• Korean Journal of Cognitive Science
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• v.18 no.4
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• pp.351-370
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• 2007

This study investigated whether top-down information influenced the filing-in of the blind spot. Two potential stimuli, which could fill in the blind spot, were presented at the location of the blind spot. When the two stimuli competed against each other to fill in the blind spot with equal probability, the depth-context of one of the stimuli was manipulated. We used an overlapping cue as our depth-context. Participants' task was to report the relative depth of a target presented in the blind spot. We found that the overlapping rue influenced the frequency of reported depth. These results, however, were nor observed in the off blind spot. These results suggest that top-down information such as an overlapping cue influences the filing-in of the blind spot.

• Korean Journal of Environment and Ecology
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• v.4 no.1
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• pp.63-68
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• 1990

User's impacts on trail deteriorations and edge vegetation were studied in Sokri Mountain National Park in 1990. The entire width, bare width and maximum depth of trail as the trail condition were significantly greater on the more heavily used trail. Deteriorations of trail which were surveyed at the total of 52 were significantly different from those of non-deteriorated points. The dominant trees in the crown layer of trail edge are as follows. According as the altitude rises, the changes happen from Quercus serrata to Quercus variabilis, Pinus densiflora, and to Quercus mongolica at Joongsajaam course, and from Pinus densiflora, Quercus variabilis to Quercus mongolica at Birosanjang course. And Stephanandra incisa, Symplocos chinesis for. pilosa show high relative dominant value at Joongsajaam course, Lindera obtusiloba, Fraxinus sieboldiana show one at Birosanjang course.