• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.17-21
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• 2007

Ultrasonic inspection method is more profitable than X-ray radiographic inspection in cost and effect of defect detection such as debond, and it doesn't need special facilities. The method can also be a possible real time inspection with safety. This report explains the experiment and theoretical modeling analysis of the inspection methods of propellant/liner debond using ultrasonic multi-reflection in rocket motor. From the results, it is possible to detect the defect of propellant/liner debond and its signal is distinguishable with normal. And, it is approximately coincide with both experimental signal and modeling.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2003.10a
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• pp.352-358
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• 2003

• The Journal of Korean Association of Computer Education
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• v.22 no.3
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• pp.89-99
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• 2019

The purpose of this study is to develop and validate assessment tools and to analyze their applicability in problem solving programming education for college students of teacher training college. For this purpose, we have redefined the area of computational thinking and detail elements from the viewpoint of problem solving programming, and developed paper type inspection and self - report questionnaires to evaluate them. The reliability and validity were analyzed by applying the evaluation tool developed for the actual college students of teacher training college. Through this study, it was confirmed that the paper type inspection and self - report questionnaires developed in this study can be used as a tool to computational thinking assessment.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.2
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• pp.185-191
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• 2000

The safety problem of aged tunnels has been emphasized. For the effective maintenance, site inspection of tunnel structures and surrounding grounds are required periodically. Also, the determination of safety of tunnels is not a simple problem. So the role experienced engineer in the maintenance is very important and development of an expert system that can perform as the engineers, has been needed. In this study, from the results of numerical analysis in several case, new precision inspection rules which can substitute actual numerical analysis are determined by a commercial program FLAC and regression analysis under various parameters such as material property, lining thickness, overburden and laterial coefficients. They are added to the knowledge base to determine safety of tunnel lining. To verify the expert system, the results are compared with an existing tunnel diagnosis report. It can be concluded that the new rule are well represented the actual numerical analysis under various site conditions. Therefore it is expected that the systematic management for effective maintenance of tunnel structure will be possible.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.239-245
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• 2006

Ultrasonic inspection method is more profitable than X-ray radiographic inspection in cost and effect of defect detection such as dis-bond, damage, and it does'nt need special constructions and can be possible real time inspection with safety. This report explains the experiment and analysis of ultrasonic property of solid propellant and the inspection methods of propellant/liner dis-bond by inside or outside inspection, and of propellnat micro crack by damage. At result, ultrasonics has big attenuation$(6\sim8db/cm)$ in solid propellant, and it. can be possiblle to detect the defect of propellant/liner dis-bond by inside or outside inspection. And also it can be possible to detect the propellant micro crack caused by damage by using ultrasonic attenuation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.166-167
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• 2013

There has been a defect dispute of apartment building in Korea. The defect dispute is complicated by main issues and details of dispute. It is yet to be solved. Meanwhile, a judge does not a inspection and analysis, but, related field expert who contracted professional engineer does. As a result, defect consulting report that an important judgment is used in a defect dispute. Therefore, this study does research on structure of defect consulting report. A defect consulting report has same items, irrespective of a defect consultant as a result that check 7 indexes about 10 cases. It has different structure's details depending on each defect consultants. And, it inserts new detail or deletes existing detail, does not show clear distinction.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.10 no.1
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• pp.20-24
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• 2014

Recently, it is getting more and more important ensuring the integrity for the equipment degradation according to the increase of nuclear power plant operating period. In many equipment of the nuclear power plant, snubbers mainly installed in reactor coolant pumps, steam generators and piping protected the equipment and piping from the occurrence of transient dynamic loads such as the earthquake, thermal load during the plant operation. This report describes the function, regulation, inspection requirements and management status of the snubbers installed in domestic nuclear power plants.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.11
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• pp.974-978
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• 2013

AVI (Automatic Vision Inspection) systems automatically detect defect features and measure their sizes via camera vision. AVI systems usually report different measurements on the same defect with some variations on position or rotation mainly because different images are provided. This is caused by possible variations from the image acquisition process including optical factors, nonuniform illumination, random noises, and so on. For this reason, conventional area based defect measuring methods have problems of robustness and consistency. In this paper, we propose a new defect size measuring method to overcome this problem, utilizing volume information that is completely ignored in the area based defect measuring method. The results show that our proposed method dramatically improves the robustness and consistency of defect size measurement.

• Journal of Veterinary Clinics
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• v.29 no.4
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• pp.315-318
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• 2012

This report describes a case of foot and mouth disease (FMD) in farm-raised Sika deer. FMD serotype A occurred in six cattle farms in January 2010 since the outbreak of pig cases 2002 in South Korea. In addition to the six cattle farms where the disease occurred during January, positive reactions to FMD antibodies were found in two heads of deer on March at a deer farm in serological tests intended to lift the movement restriction of the susceptible animals imposed within risk zone. In the specimens collected from 12 heads for confirmatory tests in the same farm, no virus was detected in antigen tests and neutralising antibody titers in all raising deer in the farm were relatively high. So it seems likely that the animals had been infected with FMD at least one month earlier when they were found.

• Journal of radiological science and technology
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• v.41 no.5
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• pp.493-504
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• 2018

The diagnostic radiation equipment is managed in accordance with the "Rules for Safety Management of Diagnostic Radiation Equipment" enacted in 1995. The equipments should be inspected before use and every three years after use in accordance with the [Appendix 1] of the same rule. The inspection standard has been maintained without particular revision since enacted. But, over the past two decades new types of equipments have been manufactured and used. So, it is necessary to revise [Appendix 1] by making inspection items and inspection standards. In this study, we revised the classification system of equipments and reviewed international standards of IEC 60601 series, IEC 61223 series and AAPM TG 18 On-line Report No.03. And identified the problem of current inspection standards. Through this, we revised, deleted and added the inspection items and inspection standard of each equipment to meet the domestic circumstances. As a result of the study, we reorganized the classification system of equipment which are current classified as 5 classes into 22 classes as X-ray system etc. (7 classes), CT system etc. (5 classes) and Dental X-ray system etc. (10 classes). And then, we developed 70 inspection items for 6 types of equipments according to the reorganized classification system of equipments. The inspection items and inspection standards derived from this study have been proposed to the KCDC and will be applied to the revision of the Rule's [Appendix 1]. Therefore, we expect to be used as reference materials for domestic medical center, inspection institutions, and equipment manufacturing import companies.