• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.993-996
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• 2008

It has been reported that destruction test by core collection is the most reliable of the structural concrete strength in present building construction field. But it causes low efficiency by damage and cutting in structure due to the core collection. It also has some problems in repairing. Additionally in case of strength test with management specimen, different environment compared to the structure environment cause problems about estimation precise structure strength. Therefore, it is required to develop structure direct strength test that has test values and credibility above the ones obtained by core specimen collection strength test and seasonal specimen test to suggest a reasonable and practical management method of structural concrete.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.2
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• pp.10-16
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• 2012

A computational analysis of nozzle flow characteristics and plume structure is conducted to examine performance of the supersonic nozzle employed in a thruster for ground firing test. At first, flow simulations in two-dimensional converging-diverging nozzle are performed for the verification of computational capability as well as turbulence model validity. Axisymmetric converging-diverging nozzles for ground firing test are analyzed with the k-${\omega}$ SST model. A performance penalty caused by flow separation in a diverging section is observed in initially-designed nozzle. The performance could be enhanced by the modification of the diverging section of nozzle contour.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.22-22
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• 2018

의료기기는 사용목적과 사용 시 인체에 미치는 잠재적 위해성의 정도에 따라 4개의 등급으로 분류하며, 두 가지 이상의 등급에 해당되는 제품의 경우에는 가장 높은 등급으로 분류하게 된다. 의료기기 품목허가를 위해서는 기술문서를 작성하여야 하며, 이를 위해서는 기술문서 심사를 신청하는 절차를 이해하여야 한다. 의료기기 기술문서란 의료기기의 성능과 안전성 등 품질에 관한 자료로서 해당 품목의 원자재, 구조, 사용목적, 사용방법, 작용원리, 사용 시 주의사항, 시험규격 등이 포함되는 문서를 말하며, '의료기기 허가 신청서'와 '첨부자료(임상시험자료 포함)'로 구성되어 있다. 의료기기 품목허가 시 제출되는 기술문서를 통하여 해당 의료기기의 안전성 및 성능이 충분히 입증되어야 하며, 인체 삽입되는 표면처리 임플란트를 포함한 인체 접촉 의료기기의 안전성의 경우 '의료기기의 생물학적 안전에 관한 공통 기준규격'에 따라 평가 후 제조 수입품목 허가를 진행해야 한다. 또한 성능의 경우는 해당 규격 또는 자사의 기준 및 시험방법에 따른 성능에 관한 자료, 물리 화학적 특성에 관한 자료를 통하여 평가되어야 하며, 기허가 인증된 제품에 한 번도 사용되지 않은 원재료 또는 적용부위 및 적용방법이 달라 안전성 및 유효성 확인이 필요한 경우 임상시험에 관한 자료가 요구될 수 있다. 본 발표에서는 이러한 인체 삽입용 표면처리 임플란트의 전반적인 인허가 절차에 대해서 안내하고자 한다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.6
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• pp.119-126
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• 2015

The wall system has been also tending to shift from existing concrete wall to variable lightweight wall according to increasing use of column structure system in apartment construction. Therefore, wall needs certain amount of strength which also means the standard measurement of resistance against loading of wall attachments is needed. Nevertheless, there currently aren't enough researches of related standards for such measurement. For such reason, the research would be used as baseline data to development for test methods of load resistance about attachments on the lightweight wall, that presented improvements in the apparatus and maximum loads for domestic circumstances by researching current tests.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.5 s.51
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• pp.107-115
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• 2006

The power supply system is one of the most important infrafacilities which should maintain their inherent function during and after earthquakes. This study was performed to analyze dynamic characteristics and seismic performance of Korean typical 154kV transformer porcelain bushing. For the purpose of this study, actual 154kV porcelain bushings were selected and tested on the shaking table. The vibration tests consist of modal identification tests, seismic performance tests, and fragility tests. The sine sweep waves, artificial earthquake waves, and continuous resonant sine waves were used as shaking table motions. This paper describes the test specimens, shaking facilities, and test methods. Natural frequencies and damping ratios of the bushing have been evaluated from the experimental data. The failure mode and the performance level of the Korean transformer bushing have been first identified in this study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6A
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• pp.457-464
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• 2011

An experimental study was performed to evaluate the possibility of using stiff type PolyUrea(PU) on RC slab as a strengthening material. Stiff type PU(STPU) was sprayed on the bottom surface of the slab specimens, which were then attached with CFRP or GFRP sheets. Also the evaluation of the bond capacity, the single most influential parameter on strengthening of RC structures, was carried out the flexural capacity evaluation test results showed that the load carrying capacity of the PU specimen was greater and less than the unstrengthened and FRP sheet attached specimens, respectively. The STPU specimens showed a ductile flexural behavior in the plastic displacement range. With respect to bond capacity, the bond strength of all of the specimen exceeded the code required bond strength of 1.5 MPa. Also, the STPU sprayed specimen without using epoxy resin did not peel off when the tensile grip was applied for testing. The stability of the PU bond failure indicate a good bond strength of PU when applied to concrete.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.2
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• pp.109-116
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• 2007

The purpose of this paper is to evaluate the fire resistant performances of load-bearing wall using both composite and steel stud panel infilled with light-weight formed mortar under axial loading according to KS F 2257(1999). The minimum requirement of 2 hours fire resistant rating is needed for the residential and commercial buildings under the fire regulation of Korea. From test results, it is found that two types of specimen composed of the hybrid stud and steel stud panel filled with light-weight formed mortar fited in with the requirement of 2 hours fire resisting rate for the load-bearing wall. In the conclusions, the specimen with hybrid stud shows predominating fire-resistant performance on the adiabatic effects rather than that of the steel stud specimen.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.320.1-320
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• 2001

• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1924-1937
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• 1996

In this paper, we propose a ESP(Extended Scan Path) architecture for multi- board testing. The conventional architectures for board testing are single scan path and multi-scan path. In the single scan path architecture, the scan path for test data is just one chain. If the scan path is faulty due to short or open, the test data is not valid. In the multi-scan path architecture, there are additional signals in multi-board testing. So conventional architectures are not adopted to multi-board testing. In the case of the ESP architecture, even though scan paths either short or open, it doesn't affect remaining other scan paths. As a result of executing parallel BIST and IEEE 1149.1 boundary scan test by using, he proposed ESP architecture, we observed to the test time is short compared with the single scan path architecture. Because the ESP architecture uses the common bus, there are not additional signals in multi-board testing. By comparing the ESP architecture with conventional one using ISCAS '85 bench mark circuit, we showed that the architecture has improved results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.11a
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• pp.30-30
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• 1997

국내에서는 시도되지 않았던 조립식 맨드렐 및 prepreg 제작 방식을 적용하여 filament winding machine으로 압력 용기(STEB)를 제작, 음향 방출 측정 장비 및 strain gage 등을 부착한 수압 시험으로 압력용기의 구조적 건전성 예측 및 파열 압력을 측정하여 성능을 분석하였다. 동일한 winding pattern 및 조건하에 prepreg winding과 wet winding 방식을 적용하여 제작한 압력 용기의 성능을 비교하였고, prepreg winding의 설계 조건, 공정 변화를 통해 제작한 압력 용기의 파열 압력 및 형태를 분석하였다. 이러한 winding 조건들에 따라 제작된 압력용기는 최종적으로 PR(Performance ratio) 값을 산출하고, 이를 통하여 prepreg 제작 방식의 장단점, 제작에 필요한 설계 조건 및 기초 자료 등을 고찰하여 보았다.