• 대한조선학회논문집
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• 제32권2호
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• pp.56-67
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• 1995

본 연구에서는 케이블 비선형 정역학 방정식의 해로서 선박-케이블-잠수체 시스템의 정적모양이 보여지고, 선형 운동 방정식의 진동수영역해석에 의해 고유진동수가 구해진다. 또한 긴 연직케이블의 스내핑 현상을 클리핑 오프(clipping-off) 수치모형으로 이상화하여 극단장력을 계산한다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권2호
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• pp.688-698
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• 2019

If heave motion in the platform causes horizontal parametric vibration of a Compliant Vertical Access Riser (CVAR), the riser may become unstable. A combination of riser parameters lies in the unstable region aggravates vibrational damage to the riser. Change of axial tensile stress in the riser combined with its natural frequency and mode shape change results in mode coupling. In accordance with the state transition matrices of the riser in the coupled and uncoupled states, the stable and unstable regions were obtained by Floquet theory, and the vibration response under different conditions was obtained. The parametric excitation of the CVAR is shown to occur mainly in first-order unstable regions. Mode coupling may cause parametric excitation in the least stable regions. Damping reduces the extent of unstable regions to a certain extent.

• Archives of Pharmacal Research
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• 제28권10호
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• pp.1161-1163
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• 2005

Five compounds of iridoids, lignan and phenylpropanoid glycosides were isolated from the roots of Valeriana jatamansi by column chromatography. Their structures were elucidated as 11-methoxyviburtinal (1), baldrinal (2), prinsepiol-4-O-${\beta}$-D-glucoside (3), coniferin (4), and hexacosanic acid (5) by spectroscopic analysis. 11-Methoxyviburtinal was a new compound, and others were isolated from the plant for the first time.

• Corrosion Science and Technology
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• 제9권4호
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• pp.143-146
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• 2010

For the issue of flaking of the hot-dip galvanizing coating during drawing, the microcosmic characteristics of the coatings have been analyzed and experiments have been done to investigate the influence of coating thickness, Al content and steel substrate strength on its flaking-resistance. The results show that the fact of flaking is that the coating partially flaked off at the position far away from interface of steel substrate and coating, and not entirely flaked off from steel substrate because of poor adhesion. The flaking-resistance of coating decreases with the increasing of coating thickness and steel substrate strength, and increases with the increasing of Al content in coating at the same experimental conditions.

• 연구논문집
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• 통권30호
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• pp.15-23
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• 2000

In this study, develop the thermal pump using water evaporation and condensation. Vapor from heating room moves up to pumping room and press the water of pumping room. Consequently water is pumped out to water tank. Then hot vapor direct contact with cold water in condensing room after pumping process. At this time, pressure of condensing room is down to-5kPa and suck in water of tank. This pump executes self ping and good durability because of no mechanical moving parts. Thermal pump is pumped cyclic so that, this pump is not used single. Therefore thermal pump of hot water boiler used to multi-stage for stable pumping rate. As the result of performance test, the developed thermal pump proves pumping action of water evaporation/condensation. And total volume flow rate is 500liter during one hour. If three thermal pump is installed parallel, this pump can use to the hot water boiler in the 300,000kcal/h class.

• Journal of the Optical Society of Korea
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• 제18권5호
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• pp.485-494
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• 2014

A novel antenna with ellipsoid-paraboloid surfaces configuration is designed for matching the incident radial radiation fiber laser distribution for maximum transmission efficiency. The on-axial and off-axial defocus effects on the optical antenna system, resulting in energy loss, are analyzed in detail. Knowledge of the effects of those defocuses on beam divergence, aberration and antenna transmission efficiency is of great importance to the long range communication systems.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2001년도 춘계학술발표대회 개요집
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• pp.318-321
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• 2001

클래딩은 주요 산업분야에 내마모성, 내부식성의 향상을 위해 사용되고 있다. 그러나 클래딩 공정에서는 모재와 클래딩 재료의 물리적, 화학적 특성의 차이와 여러 가지 공정 변수의 영향으로 제품의 사용에 치명적인 손상을 줄 수 있는 균열, 슬래그 개재물, 기공등의 불연속이 발생하기 쉽다. 본 연구에서는 클래딩 시에 발생되는 불연속을 실시간으로 검출하는데 아주 우수한 검출능력을 갖고 있는 비파괴 검사 방법인 음향방출시험을 적용하고 검출된 신호에 대한 주파수 분석과 2차원 위치표정을 실시하여 균열, 기공 등의 불연속을 검출하였고 이를 주사전자현미경을 통하여 확인하였다. 음향방출법에 의해 클래딩부에서 발생하는 결함에 대한 실시간 평가가 가능함을 입증하였으며, 특히 다층 클래딩이나 넓은 면적의 클래딩시에 불연속을 가장 신속하게 감지할 수 있으므로 이를 생산공정에 활용한다면 클래딩 또는 용접부 품질감시를 위한 효과적인 방법이 될 것이다.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제11권3호
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• pp.185-196
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• 2007

In order to study the new curriculum, as well as to help teachers understand new textbooks well, the authors make horizontal comparisons between Editions A and B of Experimental Mathematics (2) textbook in ordinary senior high schools (Grades 10-12) of PEP Edition, which focuses on the topic of line slope. The interview was made with 11 selected teachers who are teaching the content in the light of Edition B. It was found that there are obvious differences in the introduction of concepts and the exercises. The interviews showed that teachers were familiar to the contents of Edition A and saw it reasonable, because few differences are found between Edition A and the old Edition. The teachers also viewed that though the contents of Edition B were easy and fit to self-educated, but its reasoning is not clear, and the examples are not enough so that the teachers need to add additional examples.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (3)
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• pp.619-621
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• 2004

ARP는 IP 네트워크 상에서 IP 주소를 물리적 네트워크 주소로 대응시키기 위해 사용되는 프로토콜이다. 네트워크에서 데이터를 전송할 때는 컴퓨터간의 물리적 주소를 이용하여 전승하는데 이 물리적 주소는 각각의 랜카드마다 고유하게 갖는 값으로 네트워크에서는 실제로 데이터를 전달할 때 네트워크 카드가 가진 물리적 주소를 이용하여 전달 하지만 소프트웨어 차원에서는 IP 주소라는 것을 사용한다. ARP 프로토콜은 IP 주소를 실질적인 네트워크 어댑터의 물리적 주소와 연관시킬 때 사용되는 것이다. 본 논문에서는 ARP 동보 패킷을 이용한 네트워크 강시 대상 노드들의 정보를 자동적으로 구축하는 기능을 갖는 네트워크 모니터링 시스템을 설계하고 구현한다. 본 네트워크 모니터링 시스템은 ARP 동보 패킷을 분석하여 네트워크 감시 대상 노드들을 인식하고 NETBIOS 모듈을 이용한 노드 이름 확인과 Ping 모듈을 이용한 노드 상태 및 정보를 표시하며 주기적인 업데이트를 통해 노드 정보를 표시하는 기능을 갖는다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.362-367
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• 2003

A new mechanical-electrical hybrid passive dam ping treatment is proposed to improve the performance of structural vibration control. The proposed hybrid passive damping system consists of a constrained layer damping treatment and a shunt circuit. In a passive mechanical constrained layer damping, a viscoelastic material damping layer is used to control the structural vibration modes in high frequency range. The passive electrical damping is designed for targeting the vibration amplitude in the low frequency range. The governing equations of motion are derived through the Hamilton's principle. The obtained mathematical model is validated experimentally. The presented theoretical and experimental techniques provide invaluable tools for controlling the multiple modes of a vibrating structure over a wide frequency band.