• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.7
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• pp.1100-1104
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• 2017

A detector-based approach shows the limited performances for the defect inspections such as shallow fine cracks and indistinguishable defects from background. Deep learning technique is widely used for object recognition and it's applications to detect defects have been gradually attempted. Deep learning requires huge scale of learning data, but acquisition of data can be limited in some industrial application. The possibility of applying CNN which is one of the deep learning approaches for surface defect inspection is investigated for industrial parts whose detection difficulty is challenging and learning data is not sufficient. VOV is adopted for pre-processing and to obtain a resonable number of ROIs for a data augmentation. Then CNN method is applied for the classification. Three CNN networks, AlexNet, VGGNet, and mofified VGGNet are compared for experiments of defects detection.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1207-1210
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• 2002

장기간의 원자력발전소 운영과정에서 가동전 중검사는 설비의 건전성을 확인하는 매우 중요한 점검과정이다. 가동전 중검사 결과 많은 양의 검사데이터가 생산되며 이러한 검사데이터는 과거 검사결과와 비교하여 결함지시의 성장여부 등이 검토될 수 있어야 하며 후속 검사를 위한 기초 데이터로 활용될 수 있어야 한다. 또한 검사에 사용되는 검사장비, 검사자, 검사절차서, 관련 도면, Codes & Standards 등 검사자원의 체계적인 관리가 필요하며 이를 위한 정보시스템의 지원이 필수적이다. 또한 수작업으로 작성되는 가동전 중검사계획(LTP 등) 작성업무의 자동화가 필요하며, 검사계약이 경쟁체제로 전환됨에 따라 검사업체의 변경 여부에 관계없이 검사결과의 연속성이 유지되어야 하며 검사절차나 양식 등의 표준화가 필요하다. 본 논문에서는 이러한 현안사항을 개선할 수 있는 데이터베이스 응용시스템을 설계 및 구현하고 그 개발 과정을 소개한다.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.3
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• pp.271-281
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• 2010

Brazing fitting which is one of the aircraft hydraulic power system components is widely used for saving weight and achieving higher reliability. Any inherent defects or damage of fitting can cause system failure and/or physical damage of human body due to highly pressurized fluid. Radiographic testing(RT) technique and additional micro-structure investigation on cut-away surfaces have been accomplished to find out some defect-like-inhomogeneity in the fittings. The radiography results showed that some defect-like-inhomogeneity existed inside body. Additional micro-structure investigation on cut-away surface reveals that the inhomogeneity is due to internal voids. In this study, it can be is said that RT technique can be a useful tool for field acceptance test of hydraulic brazing fitting in short time.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.2
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• pp.128-134
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• 2014

Infrared thermography is an emerging approach to non-contact, non-intrusive, and non-destructive inspection of various solid materials such as metals, composites, and semiconductors for industrial and research interests. In this study, data processing was applied to infrared thermography measurements to detect defects in metals that were widely used in industrial fields. When analyzing experimental data from infrared thermographic testing, raw images were often not appropriate. Thus, various data analysis methods were used at the pre-processing and processing levels in data processing programs for quantitative analysis of defect detection and characterization; these increased the infrared non-destructive testing capabilities since subtle defects signature became apparent. A 3D finite element simulation was performed to verify and analyze the data obtained from both the experiment and the image processing techniques.

• Health Policy and Management
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• v.34 no.2
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• pp.178-184
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• 2024

Background: This study aimed to determine the effectiveness of drug utilization review (DUR) evaluation indicators on safe drug use by comparing the changes in DUR inspection rates and drug duplication prescription prevention rates between the pre- and post-implementation of the DUR evaluation indicators of the Healthcare Quality Evaluation Grant Initiative. Methods: This study used DUR data from the Health Insurance Review and Assessment Service in 2018 (pre-implementation) and the evaluation results of the Healthcare Quality Evaluation Grant Initiative in 2023 (post-implementation). The dependent variables were the DUR evaluation indicators, including DUR inspection rate and drug duplicate prescription prevention rate. The independent variable was the implementation of the DUR evaluation indicators, and the control variables included medical institution characteristics such as type, establishment classification, location, DUR billing software company, and number of beds. Results: The results of the analysis of the difference in the prevention rate of drug duplicate prescriptions between the pre- and post-implementation of the DUR evaluation indicators of the Healthcare Quality Evaluation Grant Initiative showed that the prevention rate of drug duplicate prescriptions increased statistically significantly after the implementation of the DUR evaluation indicators. Conclusion: The policy implications of this study are as follows: First, ongoing evaluation of DUR systems is needed. Second, it is necessary to establish a collaborative partnership between healthcare organizations that utilize DUR system information and the organizations that manage it.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.3
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• pp.9-18
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• 2017

Construction Management at Risk (CMAR) is a project delivery method that enables CM companies to deliver projects at a Guaranteed Maximum Price (GMP). General contractors can apply CMAR from the initial design phase right through the construction phase to reduce risks and improve project performance. One of the major advantages CMAR offers is that it permits a general contractor to provide a comprehensive suite of preconstruction services, including estimating, a constructability review, value engineering, drawings and a specification review, green building, and Building Information Modeling(BIM), among others. However, general contractors in South Korea currently provide only limited preconstruction services using CMAR because few CMAR projects have yet been implemented in Korea and their experience using the method is therefore limited. This benchmark study of how foreign general contractors utilize CMAR in their projects, particularly during the preconstruction process, its purpose, and the roles and responsibilities of each of the different participants in successful implementations thus provides invaluable information and will serve as a useful guide for Korean contractors seeking to incorporate CMAR preconstruction services in their projects and thus improve the competitiveness of their construction businesses.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.67-76
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• 2020

This paper reports an experimental study to evaluate the flexural behavior of concrete beams reinforced using Fe based shape memory alloy (Fe-SMA) bars. For the experiment, a concrete beam of 200mm×300mm×2,200mm was produced, and a 4% pre-strained Fe-SMA bar was used as a tensile reinforcement. As experimental variables, type of tensile reinforcement (SD400, Fe-SMA), reinforcement ratio (0.2, 0.39, 0.59, 0.78), activation of Fe-SMA (activation, non-activation), and joint method of Fe-SMA bar (Continuous, welding, coupler) were considered. The electric resistance heating method was used to activate the Fe-SMA bar, and a current of 5A/㎟ was supplied until the specimen reached 160℃. After the upward displacement of the specimen due to the camber effect was stabilized, a three-point flexural loading experiment was performed using an actuator of 2,000 kN capacity. As a result of the experiment, it was found that the upward displacement occurred due to the camber effect as the Fe-SMA bar was activated. The specimen that activated the Fe-SMA bar had an initial crack at a higher load than the specimen that did not activate it. However, as with general prestressed concrete, the effect of the prestress by Fe-SMA activation on the ultimate state of the beam was insignificant.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.4
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• pp.33-44
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• 2023

Wind power is one of the most efficient and reliable energy sources in the transition to a low-carbon society. In particular, offshore wind power provides a high-quality and stable wind resource compared to onshore wind power while both present a higher installed capacity than other renewables. In this paper, we present our new program, the X-WIND program well suitable for the assessment of the substructure of offshore wind turbines. We have developed this program to increase the usability of analysis programs for offshore wind energy substructures by addressing the shortcomings of existing programs. Unlike the existing programs which cannot solely perform the substructure analyses or lack pre-post processors, our X-WIND program can complete the assessment analysis for the offshore wind turbines alone. The X-WIND program is embedded in AutoCAD so that both design and analysis are performed on a single platform. This also performs static and dynamic analysis for wind, wave, and current loads, essential for offshore wind power structures, and includes pre/post processors for designs, mesh developments, graph plotting, and code checking. With this expertise, our program enhances the usability of analysis programs for offshore wind energy substructures, promoting convenience and efficiency.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.47-56
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• 2010

At present, 265 national food waste recycling facilities have been operated by public facilities 95 and private facilities 160. it has continuously installed a food waste treatment facility from 1997. The government set up and implemented guidelines and inspection standards for the installation and operation of the facilities. However, unclear detailed examination items, designs and process standards for the installation procedures of the facilities are causing problems due to the unskilled operation management system, decrease in efficiency and defects of a facility. This study conducted mail and site surveys on 95 public food waste recycling facilities that it suggest the ways to operate facilities which minimize problems. At the result of investigation, a pre-treatment facility was not installed 2 systems(2 inputting facilities) and hopper covers and food was overloaded. also the transportation amount was excessive. In case of a main treatment facility, the secondary environmental pollution was caused by inexperienced operation and the efficiency of the facility was reduced due to excessive input of food. also the operation management standards of the facilities were inappropriate. The odor and food waste leachate treatment facility is investigated as problems that are unskilled operation, lack of regular inspection and inappropriate capacity of the treatment facility. Based on the problems found through the investigation, it suggested some ways of efficient operation. this study might contribute to minimize mistakes and defects and improve the efficiency of install and operation course of food waste recycling facilities through finding.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.6 s.58
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• pp.192-203
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• 2009

In the new Seoul-Busan high speed railroad construction specially in area of city center passage the roadbed establishment is recommended the staibility for the existing subway tunnel segments of Busan subway 1st and 2nd lines regarding the appearance condition, a quality condition and the durability of the objective facility, and it evaluates the numerical analysis using MIDAS/GTS which leads the stability of the objective facility and investigatesd tunnels. Fundamental issues in tunneling under high groundwater table are discussed and the effect of groundwater on tunnel excavation was examined using a 3D stress-pore pressure coupled Finite-Element Method. Based on the results the interaction mechanism between the tunnelling and groundwater is identified. In the both of 1st and 2nd Line the maximum sinkage, unequal sinkage and the lining stress from numerical analysis are within permission and the damage degree is appearing to be disregarded. But it enforces necessary Pre-grouting in order to minimize an actual tunnel face conduct and when the tunnel is excavated it is also necessary to minimize the outflow possibility.