• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.573-580
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• 1997

본 고에서는 공력음향학에 대한 여러 분야 중에서 최근 국내에서 관심 있게 연구되어온 분야에 대하여 그 연구 내용과 연구 방법 등을 소개하고자 한다. 먼저 전형적인 유체의 소음원에 대해서 설명하고, 이에 대한 수치적 해석방법과 무향풍동을 이용한 실험, 그리고 본 음향학 이론에 대한 응용 사례들에 대해서 간략히 소개하고자 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.130-134
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• 1996

본 논문에서는 광대역 소음원의 위치를 탐지하여 2차원 영상면에 소음원을 영상화할 수 있는 3차원 마이크로폰 배열을 제안하였다. 배열요소간의 상호상관함수가 2차원 영상면의 화소의 밝기에 대응되도록 영상함수를 유도하였으며 영상면은 사각면 및 원통면등으로 선택 가능 하도록 하여 소음원의 위치동정 해석이 용이하도록 하였다. 몇가지 소음원에 대한 수치 모의 실험결과는 제안된 배열이 소음제어 분야 등에 응용 될 수 있음을 보인다.

• Journal of Korean Society of Steel Construction
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• v.18 no.1
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• pp.1-10
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• 2006

paper presents the results of the use of the differential transformation technique in analyzing the free vibration of circular plates.calculations were carried out and were compared with previously published results. The results that were obtained when this method was used coincide with the results of The present analysis shows the usefulness and validity of differential transformation in solving a solid-circular and annular-plate problem in terms of free-vibration responses.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.819-822
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• 2009

환경 소음,진동 개선의 측면에서 철도 레일 하부로 전달되는 진동 및 구조소음을 효과적으로 차단하기 위하여 국내에서도 탄성 이산지지 구조의 플로팅 슬라브를 적용하는 경우가 증가하고 있다. 플로팅 슬라브 구조설계에 있어 주안점은 방진효율 증대와 슬라브 자체 중량의 2~3배 되는 열차 주행간의 동하중에 대한 열차 주행 안정성을 고려해야 하는 점이며 열차의 고속화 경향에 따라 동하중의 증가는 더욱 커지고 있다. 본 연구에서는 이산지지 방진장치를 적용한 철도 슬라브 궤도의 동특성과 이동질량에 의한 응답을 방진장치의 지지 간격, 스프링 상수 등을 설계변수로 하여 수치해석적 방법으로 시뮬레이션하였다.

• The Journal of Korean Institute for Practical Engineering Education
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• v.3 no.2
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• pp.83-92
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• 2011

The computer program for analysis of mechanical vibration has been developed using visual C++. This program is organized in a format similar to most standard texts on the mechanical vibration. This program consists of a number of menus to perform various calculations as well as a set of dedicated graphical user interfaces. Solutions to problems are given in both graphical and numerical forms. Numerical examples show the effectiveness and applicability of the program. This program can be utilized to analyze the vibration behavior of mechanical systems.

• Journal of the Korea Computer Industry Society
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• v.5 no.3
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• pp.355-362
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• 2004

This paper presents the common and different results between the galloping cable and torsional oscillations in suspension bridge. Numerical results of the galloping cable and torsional oscillations in suspension bridge are presented by using the second-order Runge Kutta method under the initial conditions. This paper shows that large amplitude solution can coexist with the small amplitude one as the frequency and amplitude of the oscillation change. The differences in symmetry and transient effects are presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.6
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• pp.371-378
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• 1986

In the reflection and transmission of a transverse magnetic wave(TM wave) from a dielectric plane osillating sinusoidally perpendicular to ist surface, one could assume that the boundary moves with a uniform nelocity equal to the instantaneous socillating velodity. According to the extended Lorentz transform, the reflected and the transmitted field are obatained as the function of the dielectric permittivity, the oscillating velocities, and the incident angles. The above results are analyzed graphically.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.10 no.4
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• pp.193-200
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• 1985

In the reflection and transmission of a plane wave(TE) from a dielectric plane surface oscillating sinusoidally perpendicular to its surface, one could assume that the boundary moves with a uniform velocity equal to the instantaneous oscillating velocity. The reflected and the transmitted fields are obtained as the function of the incident angles, the dielecri'c permittivity, and the oscillating velocities according to the extended Lorentz transform.

• Journal of KSNVE
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• v.10 no.4
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• pp.679-685
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• 2000

A procedure is presented for calculating the magnitude and shape of impact pulses in a vibro-impact system when an arbitrary input force is applied to a point in the system. The procedure utilizes the condition that the displacements of two contacting point in the primary and secondary system are the same during a contacting period. The displacements of those points are calculated numerically through the convolution integral which involve the impulse response functions and applied forces. The validity of the calculation procedure is demonstrated by using it to calculated the impact forces of a simple system where a theoretical solution is known and also of systems for which other researchers have published results. The agreement between the results derived by the numerical method and the theoretical and also some published results is good.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.10
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• pp.791-797
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• 2003

A liquid storage rectangular tank structures are used In many fields of civil, mechanical and marine engineering. Especially, Ship structures have many tanks In contact with Inner or outer fluid, like ballast, fuel and cargo tanks. Fatigue damages are sometimes observed in these tanks which seem to be caused by resonance with exciting force of engine and propeller. Vibration characteristics of these thin walled tanks in contact with fluid near engine or propeller are strongly affected by added mass of containing fluid. Therefore it is essentially important to estimate the added mass effect to predict vibration of the tank structures. In the previous report, we have developed numerical tool of vibration analysis of 3-dimensional tank structure using finite elements for plates and boundary elements for fluid region. In the present report, using the numerical analysis, vibrations characteristics In deep water tank are investigated and discussed.