• 한국압력기기공학회 논문집
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• 제6권1호
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• pp.37-42
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• 2010

The stay cylinder weld at the steam generator of Korean Standard Nuclear Power Plants is safety class I component and is subjected to be inspected by the volumetric examination such as ultrasonic method. As accessibility of this area is limited due to the narrow space and high radiation, the existing manual inspection method involves various difficulties. Moreover operators may be exposed to internal contamination by contaminated dust during the surface buffing process to improve the inspection reliability of this area. Recently the new automatic inspection system for stay cylinder welds has been developed. The inspection system basically consists of a driving assembly, data acquisition device and signal processing units. The driving assembly is classified by 1) the scanner for inspecting and buffing the weld, 2) pillars for guiding the scanner and 3) the base frame for loading and supporting pillars. The scanner has 4 sensor modules to inspect in 4 refracted angles and 4 incident directions. These components can be inserted into the skirt of the stay cylinder through the manway hole and assembled easily by one-touch in the skirt. Data acquisition device and signal processing units developed in previous works are also newly upgraded for better processing of data analysis and evaluation. The system has been successfully demonstrated not only in the mock-up but also in the field. In this paper, newly developed inspection system for the stay cylinder weld of the steam generator is introduced and their field applications are discussed.

• 한국도로학회논문집
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• 제19권2호
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• pp.45-53
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• 2017

PURPOSES: The objectives of this study are to develop a new cold-applied crack sealant and to evaluate its properties and field applicability by comparing with other conventionally used crack sealants. METHODS : A new cold-applied crack sealant was developed by using neoprene latex to improve material properties. The fundamental properties such as viscosity, residue %, penetration, and softening point of the developed crack sealant were tested by TxDOT criteria to evaluate crack sealing capability. Moreover, the performance of the developed cold-applied crack sealant was evaluated under both laboratory and field conditions. In the laboratory, the bond property was evaluated using the developed cold-applied crack sealant and conventional hot-applied crack sealant by the bond-properties test standardized under ASTM D 6690. In the field, test sections were constructed on three areas: a trunk road, bus-only lane, and motorway, with the developed crack sealant and three conventional crack sealants. After construction, early field-inspection was performed on the test sections. RESULTS AND CONCLUSIONS : Overall, the developed cold-applied crack sealant demonstrates reasonable storage stability, durability, and bond property compared to conventional hot-applied crack sealants. From the test sections, it was established that the developed cold-applied crack sealant does not pose construction issues. Moreover, the early performance was verified through field inspection. However, as the field inspection was conducted a week after the construction, it is necessary to conduct an inspection of performance from a long-term point of view.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2002년도 학술.기술논문발표회
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• pp.117-121
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• 2002

The purpose of this study was to Identification the Risk of construction method to protect and reduce the risk of construction period. For this study we are using the pre and during construction period Inspection list. The inspection list was used by construction company for check a flaw of Construction field. So we rearrange the individual item of inspection list to match the Risk factor. This inspection list usually has the difference of importance because this list is not made by Method which is not focused on Method. Therefore, To find the difference of these importance, We surveyed this matter by doing interview of specialist group. To find the application of field and the possibility of measurement of Risk status, We tested Risk occurring frequency and it's strength by checking the level of Risk. The results of this study were as follows; Each Method Check List made out through the rearrangement of Construction Inspection list which used in construction company. To solve and compensate the matter which happened by changing the each Method Check List to each General Inspection List, we added the each Method Check List by checking the importance of check list of each process. By doing this, The Check List for finding Risk level of Method was created by using the check list of each Method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.668-670
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• 1999

We have developed a automatic surface inspection system for cold Rolled strips in steel making process for several years. We have experienced the various kinds of surface inspection systems, including linear CCD camera type and the laser type inspection system which was installed in cold rolled strips production lines. But, we did not satisfied with these inspection systems owing to insufficient detection and classification rate, real time processing performance and limited line speed of real production lines. In order to increase detection and computing power, we have used the Dark Field illumination with Infra_Red LED, Bright Field illumination with Xenon Lamp, Parallel Computing Processor with Area typed CCD camera and full software based image processing technique for the ease up_grading and maintenance. In this paper, we introduced the automatic inspection system and real time image processing technique using the Object Detection, Defect Detection, Classification algorithms. As a result of experiment, under the situation of the high speed processed line(max 1000 meter per minute) defect detection is above 90% for all occurred defects in real line, defect name classification rate is about 80% for most frequently occurred 8 defect, and defect grade classification rate is 84% for name classified defect.

• 한국화재소방학회논문지
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• 제22권4호
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• pp.50-53
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• 2008

본 연구는 우리나라 소화설비중 화재감지기 자체점검의 문제점 및 개선방안에 대하여 고찰하였다. 화재감지기의 현장점검시 사용되고 있는 현장점검용 기기의 신뢰도 및 성능 분석을 통하여 현장점검의 문제점을 파악하고 개선방안을 도출하는데 초점을 두었다. 분석결과 현장에서 사용되고 있는 화재감지기 현장점검용 기기의 신뢰도 및 성능상에 문제와 점검방법상에 문제가 있는 것을 확인 할 수 있었다.

• 한국건축시공학회지
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• 제2권4호
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• pp.131-135
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• 2002

The purpose of this study was to Identification the Risk of construction method to protect and reduce the risk of construction period. For this study we are using the pre and during construction period Inspection list. The inspection list was used by construction company for check a flaw of Construction field. So we rearrange the individual item of inspection list to match the Risk factor. This inspection list usually has the difference of importance because this list is not made by Method which is not focused on Method. Therefore, To find the difference of these importance, We surveyed this matter by doing interview of specialist group. To find the application of field and the possibility of measurement of Risk status, We tested Risk occurring frequency and it's strength by checking the level of Risk. The results of this study were as follows; Each Method Check List made out through the rearrangement of Construction Inspection list which used in construction company. To solve and compensate the matter which happened by changing the each Method Check List to each General Inspection List, we added the each Method Check List by checking the importance of check list of each process. By doing this, The Check List for finding Risk level of Method was created by using the check list of each Method.

• 한국정밀공학회지
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• 제24권11호
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• pp.76-83
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• 2007

The dark-field laser scattering system has been developed to inspect surface defects in infrared cut-off filters and then laser scattering characteristics against the defects are investigated. The qualitative analysis for the reliable and accurate detection performance is described through the correlation between incident angles of a laser and viewing ones of a camera. In this paper, reliable and important information with laser scattering is given for the surface defect inspection of IR filters. Its performance has been verified through various experiments.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1442-1447
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• 2003

Computer is a very powerful machine which is widely using for data processing, DB construction, peripheral device control, image processing etc. Consequently, many researches and developments have progressed for high performance processing unit, and other devices. Especially, the core units such as semiconductor parts are rapidly growing so that high-integration, high-performance, microminiat turization is possible. The packaging in the semiconductor industry is very important technique to de determine the performance of the system that the semiconductor is used. In this paper, the inspection of the inner defects such as delamination, void, crack, etc. in the semiconductor packages is studied. ESPI which is a non-contact, non-destructive, and full-field inspection method is used for the inner defect inspection and its results are compared with that of C-Scan method.

• 한국철도학회논문집
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• 제5권2호
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• pp.104-111
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• 2002

The purpose of interlocking system was to prevent the route for a train being set up and its protecting signal cleared if there was already another, conflicting route set up and the protecting signal for that route cleared. This paper proposed Interlocking Inspection System(IIS) consisting of interlocking simulator and field simulator to operate interlocking test of computer based Electronic Interlocking System(EIS) in this paper. Interlocking simulator consists of Design Edit System(DES), Logical Database Management Tool(LDMT) and real-time confirming system, field simulator is a equipment to simulate a control object of EIS and constitutes configuration operated in 19 inch standard rack. As a result of test to prove capacity of this IIS, the efficiency was shown as excellent. Therefore by using inspection system, we obtain every advantages. It has the functions for test data generation and automatic test execution based on personal computer. Time and cost for test work can be reduced more efficiently by using this developed inspection system

• 한국구조물진단유지관리공학회 논문집
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• 제2권2호
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• pp.151-161
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• 1998

In this study, an attempt is made to apply the concept of fuzzy-bayesian theory to the integrity assessment of RC highway bridge, and uncertainty states are represented in terms of fuzzy sets which define several linguistic variables such as "very good", "good", "average", "poor", "very poor", etc. Especially, the concept of fuzzy conditional probability aids to derive a new reliability analysis which includes the subjective assessment of engineers without introducing any additional correction factors. The fuzzy concept are also used as reliability indexes for the condition assessment based on the proposed models, the proposed fuzzy theory-based approach with the results of visual inspection and extensive field load tests are applied to the integrity assessment of a new RC highway bridge, namely, Jichok bridge.