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        검색결과 93

        61.
        2019.10 서비스 종료(열람 제한)
        콘크리트 구조물의 균열은 재료의 성질, 시공방법, 환경 및 외력, 설계 등 많은 요인으로 인해 발생한다. 균열은 구조물에 치명적인 손실을 초래할 수 있다. 따라서 콘크리트 구조물의 균열을 조사하는 것은 검사 과정 중 중요한 평가로 인지되어 지고 있다. 그러나 과거 균열을 측정 및 평가하는 방법에 대해 신뢰성을 가진 측정 방법이 없어 균열 조사에 대해 경험이 있는 특정 조사자가 육안으로 균열을 확인하였다. 이는 비용, 시간, 정확도 및 안전성 측면에서 비효율적이다. 따라서 본 연구에서는 영상 처리 기법의 라플라시안 필터를 이용하여 구조물의 최대 균열 폭을 평가하는 방법을 제안하고자 하였다.
        62.
        2019.04 서비스 종료(열람 제한)
        Pavement condition deteriorates due to various environmental issues. This can be seen on the pavement surface as a form of distress. A crack can be considered as a typical form of pavement distress in which it may reveal a critical condition of the road. Therefore, automatic and accurate detection of pavement crack and segmentation are crucial for pavement condition assessment and maintenance.
        63.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        In this paper, we propose an algorithm that estimates the location of lunar rover using IMU and vision system instead of the dead-reckoning method using IMU and encoder, which is difficult to estimate the exact distance due to the accumulated error and slip. First, in the lunar environment, magnetic fields are not uniform, unlike the Earth, so only acceleration and gyro sensor data were used for the localization. These data were applied to extended kalman filter to estimate Roll, Pitch, Yaw Euler angles of the exploration rover. Also, the lunar module has special color which can not be seen in the lunar environment. Therefore, the lunar module were correctly recognized by applying the HSV color filter to the stereo image taken by lunar rover. Then, the distance between the exploration rover and the lunar module was estimated through SIFT feature point matching algorithm and geometry. Finally, the estimated Euler angles and distances were used to estimate the current position of the rover from the lunar module. The performance of the proposed algorithm was been compared to the conventional algorithm to show the superiority of the proposed algorithm.
        64.
        2018.10 서비스 종료(열람 제한)
        In this study, we adapted very low resolution (240x320 = 76,800 pixels) images by which it is difficult to detect cracks. An automatic crack detection technique has been studied using digital image processing technology for low resolution images of sewage pipeline. Authors have developed two algorithms to detect cracks. The third step covers an algorithm developed to find optimal threshold value, and the sixth step deals with algorithm to determine cracks. As the result, in spite of very low-resolution images, the performance of crack detection turned out to be excellent.
        65.
        2018.08 KCI 등재 서비스 종료(열람 제한)
        하상재료 조사는 유사량 계산 및 하상변동과 같은 하도 계획에 필요한 기초 자료로서 입도분포, 비중, 다공성 등을 조사하는 것이다. 원칙적으로, 조사 지점은 하천 종단 방향으로 1 km 간격이고 하나의 횡단면에 3 개 이상이다. 따라서 조사 대상 하천의 종단 길이에 따라 조사 지점이 아주 많아지기 때문에 조사에 소요되는 시간과 비용이 상당히 증가한다. 본 연구는 입도분석법인 체적법과 화상해석법의 작업 효율성과 비용을 비교하고, 화상해석법의 적용 가능성을 검토하였다. 화상해석법에 의하여 환산된 등가원의 직경이 하상재료 입도분석에 적용될 수 있음을 확인하였다. 또한, 체적법과 화상해석법의 작업효율성과 비용을 분석한 결과 약 80%의 절감효과가 있음을 입증하였다.
        66.
        2018.04 서비스 종료(열람 제한)
        In this study, the 3 point-bending test was performed on the RC T-beam and the image processing method was used to analyze the change of curvature according to the step of loading. As the loading step progressed, the bending deformation and inflection point of curvature by shear cracks occurred. It will be possible to evaluate the detailed behavior of the RC structure by using the image processing method used in this study.
        67.
        2018.04 서비스 종료(열람 제한)
        This paper proposes a deep learning-based crack evaluation technique using hybrid images. The use of the hybrid images combining vision and infrared images are able to improve crack detectability while minimizing false alarms. In particular, large-scale infrastructures can be inspected by an UAV-mounted hybrid image scanning (HIS) system, and the corresponding huge amount of data is typically difficult to be analyzed by experts. To automate such making-decision process, deep convolutional neural network is used in this study. As the very first stage, a lab-scale HIS system is developed using a scanning zig and experimentally validated using a concrete specimen with various-size cracks. The test results reveal that macro- and micro-cracks are successfully and automatically detected with minimizing false-alarms.
        68.
        2017.09 서비스 종료(열람 제한)
        In this study, a vision-based monitoring system was applied to measure the dynamic characteristics of the stay cable. The image was acquired during the day to measure the dynamic characteristics of the stay cable and the image filter processing algorithm was applied to reduce the analytical noise of the image.
        69.
        2017.09 서비스 종료(열람 제한)
        Experimental investigation of the tuned liquid column damper (TLCD) is a primal factory task prior to its installation at a site and is mainly undertaken by a real-time hybrid simulation. In this study, a noncontact standalone vision sensing system is developed to replace a series of the conventional sensors installed at the TLCD tested. The versatile measurements of the system is theoretically and experimentally evaluated through a wide range of lab scale dynamic tests.
        70.
        2017.04 서비스 종료(열람 제한)
        We designed and implemented automatic pavement damage detector using an image processing algorithm on driving condition. The experimental results show that the detector is able to successfully monitor and detect pavement damages
        71.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        We designed and implemented automatic pavement damage detector using an image processing algorithm on driving condition. The experimental results show that the detector is able to successfully monitor and detect pavement damages.
        72.
        2016.10 서비스 종료(열람 제한)
        In this study, the image processing technique referred as night vision was introduced in order to measure the displacement of structure during the nighttime. The validation of the reliability and the applicability of proposed method was evaluated by the scaled model test.
        73.
        2016.10 서비스 종료(열람 제한)
        The purpose of this study is a image processing program development to consider the domestic situation of GPR detection. Therefore the image processing program will be developed to extract and to visualize the measured raw data.
        74.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        To get the empirical data of GPR detection and to develop the image prosessing program of GPR detection data, GPR detection were proceed by the underground pipes and cavities buried in the Chamber. In the case of non pavement and asphalt pavement, water filled cavity that was buried in 0.7m depth was able to detection. But in the case of 1.0 m and 1.3 m buring depth, water filled cavity was not able to detection. In the case of non-reinforced and reinforced concrete pavement, it was difficult to detect the cavity caused by signal interference. GPRiPP programs was developed for image processing of the GPR detection data. The major processing algorithm were background removal, stacking and gain function. With proper image processing of gain function and background removal in GPRiPP program, it was showed that similar results can be obtained with conventional image processing program.
        75.
        2016.05 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 철근의 인장시험에서 변형률에 대한 상세 측정을 위하여 이미지 프로세싱을 이용하고, 변형률 분포와 넥킹구간을 평가하였다. 이미지 프로세싱 방법으로는 기존의 회색조영상을 이용한 방법이 아닌 칼라영상의 색상정보를 분석하여, 원하는 타겟과 가장 일 치하는 영역과 그 외의 영역으로 구분하여 이진영상으로 변환하는 방법을 사용하였다. 변환된 이진영상에서 개별 타겟들의 도심점을 산출한 후 각 도심점의 상대변위값을 변형률로 환산하였다. 인장실험은 ASTM A615 기준으로 제작된 grade 60 철근 중 D22와 D29에 대해서 시험을 수행하였다. 이미지 프로세싱을 이용하여 계측된 변형률 결과를 기존 변형률 게이지를 이용하여 계측한 결과와 비교하여, 본 연구에서 사용한 이미지 프로세싱 방법에 대해서 검증하였다. 이미지 프로세싱을 이용하여 초기 탄성구간의 변형률 뿐만 아니라 넥킹구간에서 발생한 0.5 (50%) 이상의 변형률도 계측이 가능한 것을 확인하였다. 본 연구결과 이미지 프로세싱을 통하여 기존 변형률 게이지의 계측한계를 극복가능 하고, 다양한 지점에서 자유롭게 계측할 수 있음을 알 수 있었다.
        76.
        2016.04 서비스 종료(열람 제한)
        In this study, Cavities in Specimens were find using GPR equipment. Results of exploration deadline for plain concrete, reinforced concrete, asphalt, gravel, depending on the type, asphalt pavement was most clearly exploration. Developed GPRiPP can represent a good cavitation through the image processing with the background removal.
        77.
        2015.10 서비스 종료(열람 제한)
        Conventional strain gauge can measure about 15~20% elongation. However, when the steel are ruptured, the strain at the necking region can be much higher than the measurement capacity of the conventional strain gauge. To measure the maximum strain at the necking region a new measurement technique should be developed. In this study, for this purpose image processing method for measuring 2-D strain distribution of tensile specimen of steel is proposed.
        78.
        2015.10 서비스 종료(열람 제한)
        In this paper, we propose an image-based measurement method of structure dynamic characteristics to assess the damage of structure in a more cost-effective way than traditional structure health monitoring system.
        79.
        2015.04 서비스 종료(열람 제한)
        In this study, longitudinal strain distribution of spliced rebar in the 1-directional tension test are evaluated with an image processing method (IPM). From these results, it is estimated that the coupler can decrease the elongation at the ultimate load, therefore, the spliced rebar with coupler should be evaluated to be used in the RC structure with LSD.
        80.
        2015.04 서비스 종료(열람 제한)
        In this study, the crack detecting system with digital image processing techniques based on the mathematical morphology method was developed to detect cracks in concrete structures. In the developed system, the image combining technique of reconstructing multiple images as an entire single image considering efficient management of analysis results was applied as an additional module.
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