• 한국생산제조학회지
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• 제22권1호
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• pp.150-155
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• 2013

This work present a new method of sealing inspection system for vehicle in which foam rubber materials are used for sealing the vehicle parts. This system is composed from a devices comprising non-contact and real-time scanning on visual inspection in machine parts. We have been investigated qualitative factors that influenced on sealing system of vehicle structure which flexibly attenuated vibration and plenty of foam rubber materials having elastic property. However, there are different factors which still depended on outdated technique (personnel subjective judgment) in the performance inspection of rubber parts, specially for cross section inspection. Through a newly developed inspection system which recently applied for the production line, we successfully achieved more effective results of matching rate by about 80 % in the sealing performance inspection with 0.7% to 1.4% in the repeated errors. These are resulted from non-contacted response by CCD camera and vision program using geometry matching method. We expect that this system may be widely applied in the strict inspection parts of more diverse cross-section in future.

• International Journal of Internet, Broadcasting and Communication
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• 제7권2호
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• pp.109-112
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• 2015

The Korean electric railway is growing rapidly such as speed of 300km/h in high speed section and 230km/h in the conventional railway section. But, power supply failure occurs because of loss of contact, defective catenary system and high speed vehicle. Therefore preventive maintenance way based reliability has been applied. Typical example is the facility inspection method using trolley inspection system. But it is required differentiated inspection method to prevent problem such as inspection errors. In this paper, a study on the trolley sliding condition inspection system using monitoring techniques is performed for performance enhancement of inspection system. It proposed the efficient maintenance method through monitoring the deviation and height of contact wire after installing inspection system on the top of train which operates in the metropolitan area. Inspection errors were decreased by virtually monitoring the video of faulty facilities. Also those facilities were identified through the impact sound analysis and tests at the main catenary section.

• 한국정밀공학회지
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• 제28권6호
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• pp.738-744
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• 2011

The reliability of blade root fixing section is required to endure the centrifugal force and vibration stress for the last stage blade of steam turbine in thermal power plant. Most of the domestic steam turbine last stage blades have finger type roots. The finger type blade is very complex, so the inspection had been performed only on the exposed fixing pin cross-section area due to the difficulty of inspection. But the centrifugal force and vibration stress are also applied at the blade root finger and the crack generates, so the inspection method for finger section is necessary. For the inspection of root finger, inspection points were decided by simulating ultra-sonic path with 3D modeling, curve-shape probe and fixing jig were invented, and the characteristics analysis method of ultrasonic reflection signal and defect signal disposition method were invented. This invented method was actually executed at site and prevented the blade liberation failure by detecting the cracks at the fingers. Also, the same type blades of the other turbines were inspected periodically and the reliability of the turbine increased.

• 한국구조물진단유지관리공학회 논문집
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• 제3권2호
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• pp.141-146
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• 1999

Recently, many existing bridges has been evaluated for maintenance and protection of collapse. In this study, field measurement according to truck loads tests on the reinforce concrete T beam bridge was carried out. Comparing the results of load test and structural analysis using the moments of inertia of gross section, crack section and effective section, and the moments of inertia of section considering depth of crack, it is conclude that the evaluation of load carrying capacity using the stress modification factor from structural analysis using the moments of inertia of gross section is more rational than using the other moments of inertia of sections.

• Journal of Welding and Joining
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• 제23권5호
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• pp.43-48
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• 2005

Conventional non-destructive techniques for inspection of the weld in pipelines require significant test time and high cost. Ultrasonic guided waves have been widely studied and successfully applied to various non-destructive tests with advantage of the long-range inspection. In this paper, a study on the application of ultrasonic guided waves to the long-range inspection of the pipeline is presented using a long-range guided wave inspection system, Wavemaker SE16, GUL. The characteristics and setup of the long-range guided wave inspection system and experimental results in pipes of with various diameter are introduced. The experimental results in mock-up pipes with cluster type detects show that the minimum detectable wall thickness reduction with this guided wave system is $2\~3\%$ in the pipe cross section area. And the wall thickness reduction of $5\%$ in cross section area can be detected when actual detection level is used. Therefore, the applicability of the guided wave systeme to long-range inspection of wall thickness reduction in pipes is verified.

• 한국구조물진단유지관리공학회 논문집
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• 제4권4호
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• pp.141-148
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• 2000

Recently the Carbon Fiber Sheet(CFS) is widely used for strengthening damaged RC structures. Strengthening compression members such as column can increase ductility and strength due to the confinement effect. In this experiment, the behavior of concrete cylinders confined by CFS was examined. The confinement pressure is increased linearly as axial stress is increased in low axial stress, and the confinement effect of CFS was rapidly developed after near maximum axial stress, thus axial strength and ductility was improved. As the ratio of CPS is increased, concrete cylinders failed due to local fracture of CFS. The confinement effect of circular section is more efficient than that of rectangular section. And significant improvement of axial strength, axial strain, transverse strain at failure is observed in circular section. This is because in rectangular section the local fracture of CFS near corner may be occured, thus the strain efficiency ratio must be considered for RC structures with CFS.

• 한국구조물진단유지관리공학회 논문집
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• 제10권6호
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• pp.143-153
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• 2006

본 연구에서는 지점부 단면형고 확대를 도입한 연속 프리스트레스트 Steel I-Girder의 휨거동 특성을 파악하고자 하였다. 긴장력 도입 후 정적 휨 재하실험을 수행 하여 지점부 단면형고 확대도입 및 강연선의 배치양상, 도입된 긴장력을 실험변수로 하여 그에 따른 내하력 향상정도를 평가하였다.

• 비파괴검사학회지
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• 제24권2호
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• pp.171-179
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• 2004

가동중검사와 보수는 원자력발전소의 원자로계통설계에서 매우 중요한 설계개념이다. 액체금속로 KALIMER의 가동성 검증을 위해서 기계계통 설계에 가동중검사와 보수개념이 반영되어야 한다. 본 연구에서는 KALIMER 의 안전성과 신뢰성을 확보하기 위하여 KALIMER의 개념설계 단계에 필요한 가동중검사와 보수의 기본개념을 설정하였다. 액체금속로 가동중검사 규정인 ASME Section XI Division 3를 반영하고 KALIMER의 설계특성을 고려하여 원자로계통과 주요부품의 가동중검사와 보수에 대한 방법과 요건을 설계하고 기술하였다.

• 한국생산제조학회지
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• 제8권3호
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• pp.92-99
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• 1999

The inspection unit which is developed and used in this study, is processed the shape data from the CCD camera to seek welding bite section shape, and then calculated as a real dimension from measuring the value of each inspection item. The reason of measuring with the real in this study is came out from the image method which used for a long time, which is extricated the characteristic as the dimension of pixel by recognize pixel. The measurement method of the section shape is that we decide the thresholding value after we drew the histogram to binarizate the object. After that, we make flat the object to get rid of the noise and measure the shape of welded part through the boundarization of the object. The shape measurement is that measure the value of the welding part to adapt the actual operation program from using the ratio between the actual dimension of the standard specimen and the dimension of image, to measure the ratio between the actual product and the camera image. The inspection algorithm which estimates the quality of welded product is developed and also, the software GUI(Graphic User Interface) which processes the automatic test function of the inspection system is developed. We make the foundation of the inspection automatic system and we will help to apply other welding machine.

• 한국측량학회지
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• 제39권2호
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• pp.103-111
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• 2021

MMS (Mobile Mapping System) is being used for HD (High Definition) map construction because it enables fast and accurate data construction, and it is receiving a lot of attention. However, research on the use of MMS in the construction field is insufficient. In this study, road surveying and inspection of construction structures were performed using MMS. Through data acquisition and processing using MMS, point cloud data for the study site was created, and the accuracy was evaluated by comparing with traditional surveying methods. The accuracy analysis results showed a maximum of 0.096m, 0.091m, and 0.093m in the X, Y, and H directions, respectively. Each RMSE was 0.012m, 0.015m, and 0.006m. These result satisfy the accuracy of topographic surveying in the general survey work regulation, indicating that construction surveying using MMS is possible. In addition, a 3D model was created using the design data for the underpass road, and the inspection was performed by comparing it with the MMS data. Through inspection results, deviations in construction can be visually confirmed for the entire underground roadway. The traditional method takes 6 hours for the 4.5km section of the target area, but MMS can significantly shorten the data acquisition time to 0.5 hours. Accurate 3D data is essential data as basic data for future smart construction. With MMS, you can increase the efficiency of construction sites with fast data collection and accuracy.