• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.587-592
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• 2005

Main transformer's integrity assessment in nuclear power plant is estimated by the electrical test of electrical core and wire and the chemical analysis of insulating oil. Mechanical test or analysis has not been so far. So this study makes it with the vibration velocity rating. The vibration velocity rating in main transformer which is based on the real data of vibration velocity measurement under operating and other machinery vibration code such as ISO code is renewed.

• Journal of KSNVE
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• v.7 no.3
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• pp.419-426
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• 1997

The psychological, physiological, and material effects of ground vibrations induced from railroad were surveyed with the magnitudes of vibration sensing using questionnaire on residents living near railroad. These magnitude of vibration sensing and effects were compared as rate or percent total based on double distances from railraod. Also overall effects of railraod vibrations were compared with vibration levels measured or predicted. The about 70% of residents living within 40m from railroad sense railroad vibration, 15% of residents are influenced phychologically. But physilogical and material effects disappeared beyond 40m.

• International Journal of Automotive Technology
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• v.5 no.3
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• pp.189-194
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• 2004

The viscoelastic layer material is widely used to control the noise and vibration characteristics of the panel structure. This paper describes the design technology of the effective vibration damping treatment using the concept of the equivalent parameter of viscoelastic layer materials. Applying the equivalent parameter concepts based on theories of shell, it is possible to simulate the finite element analysis of damping layer panel treatments on the vibration characteristics of the structure. And it is achieved the reduced computational cost and the optimal design of topological distribution for the reduction of vibration effect.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.889-898
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• 2008

In this study, analyze the status and problem of a noise and vibration control laws of it through the questionnaire. The method of survey was made by questionnaires which were the civil worker 138 persons and civil servant 132 persons. Based on this survey, we suggest a improvement of the noise and vibration control laws.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.433-438
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• 2001

This study is performed to evaluate hand-arm vibration syndrome(HA VS) of the workers in swaging process. Vibration measurement and assessment of human exposure are based on the international standard(ISO 5349). Triaxial acceleration of each operation and exposure time are measured to predict the periods before finger blanching, As results, it is found that acceleration is concerned with the diameter of pipes in swaging process, and also found that combined work is more harmful than a single operation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.679-680
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• 2011

The Forced vibration characteristics of elastically restrained pipe conveying fluid with the attached mass are investigated in this paper. Based on the Euler-Bernoulli beam theory, the equation of motion is derived by using Hamilton's principle. The effect of attached mass and spring constant on forced vibration of pipe system is studied. Also, the critical flow velocities and stability maps of the valve-pipe system are obtained as each parameters.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.430-435
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• 2009

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.996-997
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• 2014

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.561-566
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• 2008

Recently, because of development of the high speed train technology, the vibration loads by train is significantly increased ever than before. This buried gas pipelines are exposed to both repeated impact loads, and, moreover, they have been influencing by vibration loads than pipeline which is not located under vehicle loads. The vibration characteristic of pipeline is examined by dynamic analysis, and variable is only train speed. Since an effect of magnitude of vibration loads is more critical than cover depth, as increasing the train speed, the vibration speed of buried pipelines is also increased. The slope of vibration velocity is changed by attenuation of wave, at train speed, 300 km/h. From the analysis results, the vibration velocity of pipelines is satisfied with the vibration velocity criteria which are established by Korea Gas Corporation. The results present operation condition of pipelines under rail loads has fully sound integrity based on KOGAS specification.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.1
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• pp.74-80
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• 2011

Front-back vibrations of high-speed elevator need to be suppressed as in the case of lateral vibrations. The dynamic model for the front-back vibrations is different from the lateral vibration model since the supporting structure varies. In this study, a dynamic model was derived using the energy method. Based on the free vibration analysis, it was observed that the fundamental frequency for the front-back vibration is slightly lower than the fundamental frequency of the lateral vibration, which means that the active vibration control should be carried out in both directions. The PPF control algorithm was applied to the numerical model under measured rail irregularities. The numerical results show that the active vibration control of elevator front-back vibration is also possible.