• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.16 no.2
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• pp.1-9
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• 2020

Large-scale industrial facility structures continue to deteriorate due to the effects of operating and environmental conditions. The problems of these industrial facilities are potentially causing economic losses, environmental pollution, casualties, and national losses. Accordingly, in order to prevent disaster accidents of large structures in advance, the necessity of diagnosing structures using non-destructive inspection techniques is being highlighted. The defect occurrence, location and defect type of the structure are important parameters for predicting the remaining life of the structure, so continuous defect observation is very important. Recently, many researchers have been actively researching real-time monitoring technology to solve these problems. Structure Health Monitoring Inspection is a technology that can identify and respond to the occurrence of defects in real time, but there is a limit to check the degree of defects and the direction of growth of defects. In order to compensate for the shortcomings of these technologies, the importance of defect imaging techniques is emerging, and in order to find defects in large structures, a method of inspecting a wide range using guided ultrasonic is effective. The work presented here introduces a calculation for the shape factor for evaluation of the damaged area, as well as a variable β parameter technique to correct a damaged shape. Also, we perform research in modeling simulation and an experiment for comparison with a suggested inspection method and verify its validity. The curved structure image obtained by the advanced RAPID algorithm showed a good match between the defect area and the shape.

• Archives of Reconstructive Microsurgery
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• v.21 no.2
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• pp.137-142
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• 2012

Purpose: To report the clinical and radiological result of the vascularized fibular epiphyseal transplantation in the treatment of humeral head deformity by septic arthritis Material & Methods: A 3 years old male who has humeral head deformity and bone defect by septic arthritis on neonatal period. We replaced bone defect as vascularized fibular epiphyseal transplantation and lengthened humerus shaft for humerus discrepancy. We followed it up for 14 years. Result: We saw the callus formation 2 months after surgery and obtained bone union, one year after surgery. The transplanted fibular bone got hypertrophy. We could check full range of motion on lt. shoulder and The bone deformity was not worsened and The graft did not displaced on last follow up. Conclusion: Humeral head reconstruction by vascularized fibular epiphyseal transplantation showed good clinical outcome.

• Journal of Chest Surgery
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• v.20 no.2
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• pp.323-327
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• 1987

Majority of patients with total anomalous pulmonary venous drainage [TAPVD] have severe symptoms within the first few months of life. And early in the experience with correction of TAPVD, hospital mortality was high, especially in infant. In Sejong General Hospital, we operated on 3 infants with TAPVD of cardiac type. Repair was performed under the conventional cardiopulmonary by pass in one case and by the total circulatory arrest in other 2 cases. Interatial septum between enlarged coronary sinus opening and interatrial septal defect was excised and the coronary sinus was radically unroofed to make wide opening between left atrium and common pulmonary venous channel. The defect in atrial septum was closed with redundant pericardial patch. Postoperative courses were uneventful except transient dysrrhythmia of A-V dissociation. They are doing well on follow up check.

• International Journal of Railway
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• v.1 no.1
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• pp.1-5
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• 2008

The railway system requires safety and reliability of service of all railway vehicles. Suitable technical systems and working methods adapted to it, which meet the requirements on safety and good order of traffic, should be maintained. For detection of defects, non-destructive testing methods-which should be quick, reliable and cost-effective - are most often used. Since failure in railway wheelset can cause a disaster, regular inspection of defects in wheels and axles are mandatory. Ultrasonic testing, acoustic emission and eddy current testing method and so on regularly check railway wheelset in service. However, it is difficult to detect a crack initiation clearly with ultrasonic testing due to noise echoes. It is necessary to develop a non-destructive technique that is superior to conventional NDT techniques in order to ensure the safety of railway wheelset. In the present paper, the new NDT technique is applied to the detection of surface defects for railway wheelset. To detect the defects for railway wheelset, the sensor for defect detection is optimized and the tests are carried out with respect to surface and internal defects each other. The results show that the surface crack depth of 1.5 mm in press fitted axle and internal crack in wheel could be detected by using the new method. The ICFPD method is useful to detect the defect that initiated in railway wheelset.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1940-1945
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• 2007

The wheelsets are one of most important component: damages in wheel tread and press fitted axle are a significant cost for railway industry. Since failure in railway wheelset can cause a disaster, regular inspection of defects in wheels and axles are mandatory. Ultrasonic testing, acoustic emission and eddy current testing method and so on regularly check railway wheelset in service. However, it is difficult to use this method because of its high viscosity and because its sensitivity is affected by temperature. Also, due to noise echoes it is difficult to detect defects initiation clearly with ultrasonic testing. It is necessary to develop a non-destructive technique that is superior to conventional NDT techniques in order to ensure the safety of railway wheelset. In the present paper, the new NDT technique is applied to the detection of surface defects for railway wheelset. To detect the defects for railway wheelset, the sensor for defect detection is optimized and the tests are carried out with respect to surface and internal defects each other. The results show that the surface crack depth of 1.5 mm in press fitted axle and internal crack in wheel could be detected by using the new method. The ICFPD method is useful to detect the defect that initiated in the tread of railway wheelset.

• Industrial Engineering and Management Systems
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• v.9 no.3
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• pp.251-261
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• 2010

This article demonstrated the application of the Fuzzy Data Envelopment Analytical Hierarchy Process (FDEAHP) to evaluate the root causes of critical defect problems occurring in the production of liquid medicine. The methodology of the research began by collecting the defect data by using Check Sheets, and ranking the significant problems by using a Pareto Diagram. Two types of major problems were found to occur, including glass fragments in the medicine and damaged lid threads. The causes of each problem were then analyzed by using Cause and Effect Diagrams. The significant causes were ranked by FDEAHP under three criteria, Severity (S), Occurrence (O) and Detection (D), followed by the framework of the FMEA Technique. Two causes with the highest Final Weight (FW) of each problem were selected to be improved, such as installing auxiliary equipment, using the Poka-Yoke system, setting the scale of the shaft and lathing the bushes of each bottle size. The results demonstrated a reduction in defects from 3.209% to 1.669% and showed that improving a few significant root causes, identified by an experienced decision maker, was sufficient to reduce the defect rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1725-1728
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• 2009

This research developed process control device and FGV pattern generating device essential for full gate visual inspection to improve process so that defect detection capability may be maximized in specified environment. The devices developed in this research, which can be swiftly replaced in case loss or error occurs, are anticipated to improve module yield as well as maintain tact loss near '0'. In addition, as a result of mounting H/W and S/W system to control detailed operation sequence in production line and executing performance check and verification, detection rates were 98.1% and 99.1% respectively for pixel defect by tact and line defect, and yield of the entire module process including gate and visual level test increased up to 98.3%.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.8
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• pp.596-600
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• 2009

To support an efficient management of software verification and validation activities, many defect prediction models have been proposed based on object oriented metrics. They usually adopt logistic regression analysis, And, they state that the correctness of prediction is about 60${\sim}$70%, We performed a similar experiment with Eclipse 3.3 to check their prediction effectiveness, However, the result shows that correctness is about 40% which is much lower than the original results. We also found that univariate logistic regression analysis produces better results than multivariate logistic regression analysis.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.513-518
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• 2019

The non-destructive testing equipment using an eddy current was developed to check for defect in the vehicle transmission component. A defect master sample was made to test all types of defects that occur in the component and also an eddy current detector was manufactured and used to test and detect all kinds of defects. In addition, testing was held against the actual defective items to investigate the cause and type of defects, and a comparative study was conducted based on results from the examination. The software system of the eddy current detector was developed so that even a non-specialist can make assessment of detect in the component from the test results displayed on the monitor.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.2
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• pp.69-81
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• 2010

A Cold Cathode Fluorescent Lamp(CCFL) is used as a LCD Monitor's backlight widely. The most common way to check CCFL's defects is an examination with the naked eye. This naked eye examination can cause an examination inconsistency and an industrial disaster. To examine CCFL defects, a shooting equipment and a defect detection algorithm are necessary. This paper shows the shooting environments for checking CCFL and presents some CCFL defect detection algorithms. As a result of experiments, our implementations showed 98.32% of successful defect detection of CCFL.