• Tribology and Lubricants
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• v.26 no.6
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• pp.341-345
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• 2010

The NAUT(Non contact Air coupled Ultrasonic Testing) is one of the ultrasonic wave inspection methods. It compensates High power ultrasound Pulser Receiver, pre-amp, air probe of high sensitivity in air to generate loss energy by NAUT methods. Generally, in case of ultrasound inspection, it applies contact methods by using couplant. However it can inspect of UT without couplant by this NAUT. The ultrasound transmission reception is composed in stable condition in NAUT. It can inspect high low material or the specimen of rough part, the narrow spot, too. The spot welding is applying the inosculation of automobile component, car body, all boards. The CFRP is necessity of NDE because of the solidity changes material according to lamella tearing. Therefore it checked on realization whether and commercialization in the spot welding and CFRP inspection that the NAUT would be applied them.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6432-6439
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• 2014

The NAUT (Non-contact Air coupled Ultrasonic Testing) technique is one of the ultrasonic testing methods that enables non-contact ultrasonic testing by compensating for the energy loss caused by the difference in acoustic impedance of air with an ultrasonic pulser receiver, PRE-AMP and high-sensitivity transducer. As the NAUT is performed in a state of steady ultrasonic transmission and reception, testing can be performed on materials of high or low temperatures or specimens with a rough surface or narrow part, which could not have been tested using the conventional contact-type testing technique. For this study, the internal defects of spot weld, which are often applied to auto parts, and CFRP parts, were tested to determine if it is practical to make the NAUT technique commercial. As the spot welded part had a high ultrasonic transmissivity, the result was shown as red. On the other hand, the part with an internal defect had a layer of air and low transmissivity, which was shown as blue. In addition, depending on the PRF (Pulse Repetition Frequency), an important factor that determines the measurement speed, the color sharpness showed differences. With the images obtained from CFRP specimens or an imaging device, it was possible to identify the shape, size and position of the internal defect within a short period of time. In this paper, it was confirmed in the above-described experiment that both internal defect detection and image processing of the defect could be possible using the NAUT technique. Moreover, it was possible to apply NAUT to the detection of internal defects in the spot welded parts or in CFRP parts, and commercialize its practical application to various fields.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.50-50
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• 2010

최근 토요타 자동차의 대량 리콜 사태로 안전과 관련된 자동차 품질에 대한 관심과 중요성이 크게 부각되었다. 본 연구에서는 나날이 높아지고 있는 자동차 품질 기준과 생산 비용 절감, 공정 자동화 요구에 부응하기 위한 차체 저항 점 용접부 품질 검사 자동화 기술 개발을 위해 적용 가능한 센서들을 비교, 검토하였다. 알려진 비파괴 검사 방법은 초음파, 와전류, 방사선 검사법 등 다양한 방법들이 존재하지만, 이 연구에서는 생산 라인 현장 적용이 가능한 소형 센서들을 중심으로 검토 영역을 제한하였다. 검토된 비파괴 검사 방법은 총 5가지 종류로 종래의 수동 초음파 검사법, 집적된 탐촉자를 이용한 3차원 초음파 검사법, NAUT(Non-contact Air-coupled Ultrasonic Test), EMAT(EletroMagnetic Acoustic Test), 그리고 너겟 프로파일러$^{TM}$이다. 이 연구에서는 각 검사법의 원리와 장단점을 설명하고 생산 라인 적용에 필요한 필수 항목들에 대해 고찰하였다.

• The Korean Journal of Zoology
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• v.35 no.3
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• pp.295-307
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• 1992

In order to study the differentiation of the epithelial cells during the development of fetal rat lung tissue, histological changeB in organotypic culture and in vivo were examined. Light microscopy and scanning electron microscopy were used to analvre the histological change in rat lung from the 15th nary of gestation to the 111th nary after birth. In organotypic culture system, the pulmonary epithelial cell differentiation was studied by scanning electron microscopy. The results obtained from this study were as follows. 1. During deveiopment of lung, the glandular stage lasted from the Isth day to the lsth naut of gestation; the canalicular stage from the 17th nay to the 19th naut of gestation; the saccuiar stage from 20th nary to the birth. Alveolar stage was observed at the 3rd nary of postnatal rat lung. 2. In organotvpic culture of fetal rat lung cells organized alveolar-like structures resembling those of in uiuo state were observed on the gelatin matrix. In contrast with in vivo state, fetal lung cells formed group of type ll pneumocytes predominently along the contours of the matrix. These cells have large apical surface, short microvilli and secreted materials which may be sunactant. These results suggested that an orsanotypic culture retaining epithelial- -mesenchvmal relationships is appropriate culture model to study the pulmonary epithelial cell (especially type ll pneumocvte) differentation.

• The Korean Journal of Zoology
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• v.34 no.3
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• pp.394-402
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• 1991

Yolk protein-3 (YP3) was purified from the ovary of Hvpharatria cunea D. and the synthesis and fate during embryogenesis of WP3 were investisated by electrophoresis and fluorography. YP3 purified through gel slice and electrophoretic elution'was determined to have M. W. of 18 Kd and consist of one subunit. Haemolymph and fat body of male and female %were electrophoresed during vifellogenic stages to indentifv the vitellosenin in female. The result showed that there was no distinct difference in electrophoretic patterns betweerl male and female. However, tissue culture of fat body and maturing ovary indicated that YP3 was svuthesized by fat body. Aiso, vP3 in iaid eggs was maintained constant untii naut s artier oviposition and then decreased, indicating that YP3 was drastically used during late embryosenesis. However, a part of YP3 was present even in newly hatched first instar larvae.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.87-88
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• 2011

다기능 선박조종시뮬레이터(Full-mission Shiphandling Simulator)를 이용한 사고분석 방법을 한국해양수산연수원이 보유한 DNV(Det Norske Veritas)선급에서 "Integrated Simulator System, NAUT AW(SIM), DYNPOS-AUT(SIM), HSC, TUG, ICE" Class로 인정하고, STCW 협약 Regulation I/12를 충족한 Russia TRANSAS사의 "NAVI-TRAINER PROFESSIONAL 5000 NTPRO 5000" Full-mission Shiphandling Simulator를 이용하여 시행하였다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.3
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• pp.36-43
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• 2016

Carbon fiber-reinforced silicon carbide (Cf-SiC) and SiC / SiC composites have high thermal conductivity, and excellent corrosion and wear resistance, a low coefficient for thermal expansion and are lightweight. This is why they are commonly used in parts of the aerospace industry to develop an aircraft thrust deflector, jet vane, combustion chamber, elevens, body flap, and a shingle. So, understanding how this state-of-the-art Cf-SiC affects both internal and external crack detection and determining issues during the manufacturing process of composite materials, should be evaluated according to valuation techniques in the external environment. In this paper, we apply a non-contact air ultrasonic technique of non-destructive testing techniques to perform a study on internal defect detection identification and assessment of carbon-fiber reinforced silicon carbide composites to perform basic research and applied research.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.1
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• pp.286-296
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• 2017

This paper conducted a simulation to research the motion of a vessel, which had the flooding accident in the Bering Sea in 2014, thereby being flooded and un-steerable. As the wind condition was very harsh, the vessel was modeled as 3D including large upper deck structures and the Fujiwara's method was used for an estimation of the effect of wind forces and moments acting on ship. In the case of wave influence, AQWA-Drift that enables considering the effects of drift force and AQWA-Naut that enables considering the effects of green water were mainly used. Basically, loading and flooding condition were equal to the accident condition but half-drained condition was also used to consider drain ability. Furthermore, both 6 DOF and 5 DOF option that Yaw motion is fixed, were utilized to compare the steerable and un-steerable condition. As a result, the author found out that what roll angle triggers green water, how often it happens, and how the vessel moves on the stormy weather condition.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.6
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• pp.1739-1750
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• 2016

This paper proposed a process for estimating the required capacity of emergency drainage system on a ship when the ship encounters a flooding accident. The process was established by selecting target vessel, making a scenario of flooding accident, considering static behavior of flooding water and the effect of ship motion due to ocean condition. In order to obtain the object of the research, MATLAB codes were developed for analyzing of static behavior of flooding water. Additionally, Ansys AQWA-NAUT was used to analyze the motion of the ship under an ocean condition and then the effect of ship motion was considered when the static behavior of flooding water was studied. The research exploited a trawler as a target vessel, and estimate the necessary capacity of the trawler's emergency drainage system by simulating a flooding water in the vessel.

• The Korean Journal of Zoology
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• v.35 no.3
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• pp.322-331
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• 1992

To investigate the svnthyesis of muscle proteins during differentiation of chicken myoblast, cvtosolic and membrane fractions were used for both sodium dodecvl sulfate polvcrylamide gel eBectrophoresis and two-dimensional gel electrophoresis. An extensive cell fusion was observed in 4 day culture. In the protein pattern of the cvtosolic fraction from SDS-PAGE. several protein bands including 250 kDa and 46 kDa showed remarkable changes during culture. the protein of 46 kDa was the most prominent one ann its optical density was the highest in 5 day culture (OD = 1.30). In the membrane fraction, band of 19.8 kDa showed the highest absorbance with 0.93 OD at 12 hr after initial plating and decreased gradually thereafter to 0.23 in 5 nay culture. From the results of two-dimensional gel electrophoresis of cytosolic fraction, the 46 kDa spot was observed as ko separated forms from culture 2 nary culture, and the sixte of this spot was the largest in 5 nay culture. In the pattern of membrane protein, the extensive appearance of newiv synthesized Proteins was found in a naut culture, but no Prominent spot was observed throughout culture. From the results of the present clay, we found that, during myoblast differentiation, the most prominent proteins were bands of 46 kDa and 19.8 kDa in cvtosolic and membrane fraction, respectively, and the appearance of new proteins was initiated at 48 hr after initial plating, and the 46 kDa protein was predominant in the cytoplasm of late culture in which extensive cell fusion was observed.