• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.489-490
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• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.481-482
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• 2010

• Information and Communications Magazine
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• v.29 no.1
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• pp.38-47
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• 2011

본고에서는 스마트 시대의 기술혁명과 새로운 패러다임 변화를 중심으로 미래 한국사회가 직면할 거대한 변화의 흐름을 살펴보고, 'High Risk Society'와 'People Power Society'라는 미래 한국사회의 주요 특징을 제시한다. 또, High Risk Society 부분은 최소화 시키고, 새로운 가치를 창출하는 People Power Society를 확대시키는 방법의 하나로 '창의적 국민파워 기반 개방형 국정 운영 패러다임' 변화를 제시하였으며, 이를 위한 새로운 국가정보화의 정책적 방향을 제시하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.103-104
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• 2011

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.1
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• pp.74-82
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• 2010

Power flow analysis(PFA) methods have shown many advantages in noise predictions and vibration analysis in medium-to-high frequency ranges. Applying the finite element technique to PFA has produced power flow finite element method(PFFEM) that can be effectively used for analysis of vibration of complicated structures. PFADS(power flow analysis design system) based on PFFEM as the vibration analysis program has been developed for vibration predictions and analysis of coupled structural systems. In this paper, to improve the function of vibro-acoustic coupled analysis in PFADS, the PFFEM has been extended for analysis of the interior noise problems in the vibro-acoustic fully coupled systems. The vibro-acoustic fully coupled PFFEM formulation based on energy coupled relations is extended to structural system model by using appropriate modifications to structural-structural, structural-acoustic and acoustic-acoustic joint matrices. It has been applied to prediction of the interior noise in two room model coupled with panels, and the PFFEM results are compared to those of statistical energy analysis(SEA).

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.4
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• pp.328-334
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• 2012

Power flow finite element method(PFFEM) combining power flow analysis(PFA) with finite element method is efficient for vibration analysis of a built-up structure, and power flow boundary element method(PFBEM) combining PFA with boundary element method is useful for predicting the noise level of a vibrating complex structure. In this paper, the coupled PFFE/PFBE method is used to investigate the vibration and radiated noise of the unmanned underwater vehicle(UUV) in water. PFFEM is employed to analyze the vibrational responses of the UUV, and PFBEM is applied to analyze the underwater radiation noise. The vibrational energy of the structure is treated as an acoustic intensity boundary condition of PFBEM to calculate underwater radiation noise. Numerical simulations are presented for the UUV in water, and reliable results have been obtained.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.2
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• pp.43-51
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• 2004

In this paper, the element combination algorithm for designing an arbitrary type of the automatic transmissions is proposed. The powertrain simulation software using this algorithm is then developed. The deliveries of the angular velocities and torques are only considered for the motion characteristics of the automatic transmissions. The effects of the vibration and noise are not considered. The automatic transmission is defined by the basic elements, i.e., planetary gear set, clutch, brake, shaft, general gear, and inertia. The transmission system is defined by the combination of these elements. The element combination matrices automatically generate the equations of motion for each shift. The self error-correcting algorithm is also developed to verify the element combination algorithm. This automotive powertrain simulation/design software with user-friendly graphic user interface has two main modules. The first module, the automatic powerflow generation module, mainly consists of the automatic powerflow and component generation algorithms. This paper covers the theory and application for the first module. The second module deals with the automatic system generation algorithm and will be discussed in the second paper.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.767-770
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• 2006

To predict vibrational energy density of simple structural-acoustic coupled systems in medium-to-high frequency ranges, Power Flow Finite Element Method(PFFEM) is used, and PFFEM sofiware, PFADS has been developed for the vibration predictions and analysis of coupled system structures in medium-to-high frequency ranges. However, it needs to consider vibro-acoustic coupled analysis to get more accurate results. Prior to implement vibro-acoustic coupled analysis functions in PFADS, research on vibro-acoustic coupled analysis using PFFEH is performed for simple models. These predictions include the indirect transmission path associated, and also the direct transmission path, and the formulation is extended to structural system model by using appropriate modifications to structural-acoustic and acoustic-acoustic joint matrices. Concerning the waves in plate and acoustic, it is possible to calculate the structural-acoustic full matrix of a model using PFFEM, and the formulations developed are implemented for two rooms surrounded by plates.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.901-904
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• 2007

The power flow analysis (PFA) can be effectively used to predict structural vibration in medium-to-high frequency ranges. In this paper, vibration experiments have been performed to observe the analytical characteristics of the power flow analysis of the vibration of various coupled plates. Those plates include two plates coupled with angles of $90^{\circ}$\;and\;30^{\circ}$, respectively. In the experiment, the loss factor and the input mobility at a source point on each coupled plate have been measured. The data for the loss factors have been used as the input data to predict the vibration of the coupled plates with PFA. The frequency response functions have been measured over the surface of the coupled plates. The comparison between the experimental results and the predicted PFA results for the frequency response functions has been performed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.4
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• pp.400-410
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• 2008

Reduction of structure-borne noise in the compartment of a car is an important task in automotive engineering. Many methods which analyze noise transfer path have been generally used for structure-borne noise. These methods are useful in solving particular problem but do not quantify the effectiveness of vibration isolation for each isolator of a vehicle. To quantify the effectiveness of vibration isolation, the vibrational power flow measurement has been used for a simple isolation system or a laboratory based isolation system. This paper identifies the transfer path of booming noise in a SUV. The powertrain used for test has a in-line 4cylinder engine and 5-shift auto-transmission. This powertrain is transversely supported by four isolators. We calculated the energy flow throughout four isolator by the measurement of power flow and the contribution of energy flow at each isolator.