• Journal of Broadcast Engineering
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• v.14 no.2
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• pp.164-177
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• 2009

The DIBR(depth image-based rendering) method gives the sense of depth to viewers by using one color image and corresponding depth image. At this time, the qualities of the generated left- and right-image depend on the baseline distance of the virtual cameras corresponding to the view of the generated left- and right-image. In this paper, we present a novel method for enhancing the sense of depth by adjusting baseline distance of virtual cameras. Geometric analysis shows that the sense of depth is better in accordance with the increasing disparity due to the reduction of the image distortion. However, the entailed image degradation is not considered. Experimental results show that there is maximum bound in the disparity increasement due to image degradation and the visual field. Since the image degradation is reduced for increasing that bound, we add a depth map preprocessing. Since the interactive service where the disparity and view position are controlled by viewers can also be provided, the proposed method can be applied to the mobile broadcasting system such as DMB as well as 3DTV system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.267-268
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• 2023

Out of an estimated 7 million buildings nationwide, approximately 38% of them have been standing for over 30 years, and this number is expected to continue to increase. Additionally, due to the Building Act, safety inspections will be mandatory for approximately 70,000 buildings annually, leading to an increase in demand for building safety inspections. However, the current building safety diagnosis heavily relies on manpower, making it difficult to diagnose locations that are hard to access, and requiring lengthy investigation periods. Therefore, this paper presents the basic research results of a non-contact concrete damage depth estimation technique using laser technology aimed at remote building safety diagnosis and shortening investigation periods.

• The Journal of Engineering Geology
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• v.11 no.1
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• pp.13-23
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• 2001

Rock slope near the road or railroad is affected by the outside temperature and iterative freezing-thawing process during winter and early spring. The purpose of this study is to analyze the stability of rock slope which is iniluenced by deterioration due to the freezing-thawing. Method of analysis is homogenization method which find the strength property of discontinuous rock mass and as a strength failure criterion, Drucker-Prager failure criterion is used, The deterioration property of real rock is obtained by a freezing-thawing labordtory test of tuff and this quantitative property is used as a basic data of stability analysis of rock mass. To evaluate the deterioration depth due to the freezing-thawing in the field rock slope, one dimensional heat conductivity equation is used and as a a result we can find the depth of which is affected by a temperature. After determined the freezing-thawing depth of model slope, the pattern of rock mass strength value of model rock slope which excess the limit of self-load is analyzed.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.3
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• pp.193-199
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• 2015

Active thermography techniques have the capability of inspecting a broad range simultaneously. By evaluating the phase difference between the defected area and the healthy area, the technique indicates the qualitative location and size of the defect. Previously, the development of the defect detection method used a variety of materials and the test specimen was done. In this study, the proposed technique of lock-in is verified with artificial specimens that have different size and depth of subsurface defects. Finally, the defect detection capability was evaluated using comparisons of the phase image and the amplitude image according to the size and depth of defects.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.82-92
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• 2012

This study proposed a new non-destructive evaluation method for concrete bridge deck deterioration using ground penetrating radar (GPR). To calculate dielectric constant of the concrete bridge deck, an extended common mid-point (XCMP) method was developed for a two-layered structure using an air-coupled GPR antenna setup. The deterioration conditions of the concrete bridge deck such as deterioration depth was evaluated based on the dielectric constant and surface-to-average dielectric constant ratio of the concrete bridge deck. A GPR field test was conducted on an old concrete bridge with asphalt concrete surfacing to validate the new evaluation method. The test results showed that the newly proposed method estimated pavement thickness and deterioration depth of the concrete deck in a reasonable level.

• Journal of Broadcast Engineering
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• v.17 no.4
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• pp.684-694
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• 2012

In the underwater environment, light is absorbed and scattered by water and floating particles, which makes the underwater images suffer from color degradation and limited visibility. Physically, the amount of the scattered light transmitted to the image is proportional to the distance between the camera and the object. In this paper, the proposed visibility enhancement. method utilizes depth images to estimate the light transmission and the degradation factor by the scattered light. To recover the scatter-free images without unnatural artifacts, the proposed method normalizes the degradation factor based on the value of each pixel of the image. Finally, the scatter-free images are obtained by removing the scattered components on the image according to the estimated transmission. The proposed method also considers the color discrepancies of underwater stereo images so that the stereo images have the same color appearance after the visibility enhancement. The experimental results show that the proposed method improves the color contrast more than 5% to 14% depending on the experimental images.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.270-272
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• 2022

한의 복진은 복부를 검사하기 위해 수행되지만 정량화되지는 않았다. 이 연구의 목표는 소화불량의 주요 증상인 흉협고만이 있는 그룹과 아닌 그룹 사이에 유의하게 차이나는 복부 측정기기의 변수를 식별하는 것이다. 정량적인 진단을 위해 규칙에 따라 구획한 복부를 적외선 열화상 카메라, 디지털 압통기, 3D 카메라 및 디지털 청진기를 포함한 기기로 측정하였다. 연구방법으로 임상연구를 수행하여 한의사들이 진단한 복부 증상인 흉협고만과의 일치도를 조사하였다. 기기 측정 중 깊이, 압력, 깊이에 대한 압력의 비율은 흉협고만 그룹이 비 흉협고만 그룹보다 유의하게 작았다. 따라서 물리적 압통 특성이 감소하고, 복부 경직도가 감소하며, 민감도가 증가했다. 좌측과 우측 늑골 사이의 거리, 흉늑골 각도는 흉협고만 환자에서 유의하게 더 컸다. 또한, 깊이 차이, 표면 법선 벡터 및 깊이 값 사이의 각도 차이는 흉협고만 그룹에서 대부분 작았다. 복부 측정기기는 다양한 질환 및 증상에 사용될 것으로 기대한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.83-89
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• 2018

The thermal characteristics of concrete specimens were analyzed using cement paste specimens with artificial cracks. In order to understand the temperature characteristics of the specimen depending on the crack depth, the specimen was heated and the minimum temperatures of the specimens at which cracks appear were investigated according to the crack depth. It was confirmed that the surface temperature distribution of the specimen varies depending on whether the specimen is cracked or not, because of the single and multiple reflections of the incident energy. Furthermore, as the temperature distribution of the specimen reaches a steady state, the temperature data tends to decrease with the crack depth. Through the observation of the normalized temperatures, it was found that the temperature of the specimens obtained from this experiment reached a steady state after 10 minutes. At this time, the standard deviation of the normalized temperature is around 0.01 or less, and the temperature decreases linearly with increasing crack depth. This result is considered to be closely related to the area where multiple reflections occur in the cracked region. If the correlation between the crack region and the incident energy is analyzed for various specimens, it can be applied to the diffuse reflection of the light.

• Journal of the Korea Society of Computer and Information
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• v.17 no.4
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• pp.51-58
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• 2012

Recently, 3D technology based on depth image is widely used in various fields including 3D space recognition, image acquisition, interaction, and games. Depth camera is used in order to produce depth image, various types of effort are made to improve quality of the depth image. In this paper, we suggests using area-based Canny edge detector to improve depth image in applying 3D technology based on depth camera. The suggested method provides improved depth image with pre-processing and post-processing by fixing image quality deterioration, which may take place in acquiring depth image in a limited environment. For objective image quality evaluation, we have confirmed that the image is improved by 0.42dB at maximum, by applying and comparing improved depth image to virtual view reference software. In addition, with DSCQS(Double Stimulus Continuous Quality Scale) evaluation method, we are reassured of the effectiveness of improved depth image through objective evaluation of subjective quality.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.539-541
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• 2005

본 연구의 목적은 배전선로에서 운용중인개폐기, 변압기, 피뢰기 등의 규정 접지저항을 확보코자 시행하는 접지공사에 필요한 접지봉을 땅속 깊이 시공할 수 있는 접지봉의 개발과 접지봉 시공용 기계식 타격장치를 개발 활용하는 효율적, 경제적인 접지공법을 연구함에 있다. 또한 접지봉의 경년열화특성을 최소화하고자 접지봉의 접속부 구조를 개선하여 경년열화 특성을 향상하는데 있다. 특히, 굴착이 곤란한 도심지에서 최소 면적만을 굴착하여 규정 접지저항을 확보하는 방법을 제시하고 접지의 설계 및 시공 둥 실무에 활용할 수 있도록 하였다.