• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.764-769
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• 2007

This paper is studied the noise and vibration characteristics analysis of the three-phase induction AC motor of the electrical forklift. And we suggest the method which the reduction orders the noise and vibration to be the mechanical. In other to investigate these characteristics, we considered the mechanical characteristics, the electromagnetic effects, and these interactions. In mechanical, we studied the characteristic of the stator, the bearing supported condition of the rotor, and the sound radiation. In electronically, this paper is considered the harmonic effect which is related the magnetic motive force (mmf) with respect to the characteristic of the slot number of the rotor and the stator and the pole number of the motor. Finally we investigated the overall noise and vibration of the induction motor by relations between the electronically harmonic and the mechanical resonance of the stator. By the analysis of the generally three-phase induction motor, we suggest the design methodology to low noise and vibration.

• Journal of The Korean Digital Architecture Interior Association
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• v.5 no.2
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• pp.36-42
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• 2005

The interest about noise and vibration which occurs in buildings is increasing by a living level elevation recently. Particularly, the vibration which occurs from the elevator cage of the building is possibility of damage to the users of the building continuously. So, the purpose of this study is a placeThe interest about noise and vibration which occurs in buildings is increasing by a living level elevation recently. Particularly, the noise and vibration which occurs from the elevator of the building is possibility of damage to the users of the building continuously. So, the objective of this research is to investigate the noise and vibration of the elevator and propose the method which reduces of it gained thorough this study.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.875-878
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• 2004

The noise and vibration diagnostic of the industrial robot reducer is ultimately the purpose. We evaluated a noise and vibration tendency of the industrial robot reducer to be made in the outside (RV reducer) through the experiment. Also, we compared the RV reducer to the industrial robot reducer (RD reducer) in the domestic. We measured the noise level with the sound level meter and analyzed the vibration tendency with the waterfall plot. Through the comparison of RV reducer and RD reducer diagnose the industrial robot reducer. We guessed the improvement direction of RD reducer. (The domestic's industrial robot reducer).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.342-352
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• 2003

Idle NVH characteristics are one of the most important aspects among the vehicle performances. Vehicle developers are devoted to improve vehicle interior noise and steering wheel and seat vibrations. In order to improve the idle quality, noise and vibration transfer path should be carefully evaluated. Also, effects of various components related to the idle performance should be confirmed. A general procedure for improving the idle qualify is described in detail. The relationship among cylinder pressure characteristics, crankshaft rotational speed variation, and vehicle vibrations is also investigated. Influences of drive shaft, torque converter, air conditioning system, vehicle structure including engine mount system, and idle control parameters on the vehicle idle quality are studied. Weak points of typical vehicles on the idle qualify are identified. Some of improvement measures are proposed and verified.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.1041-1042
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• 2004

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.360-368
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• 2010

Noise and vibration triggered by pile driving in a construction site not only give hard time to the surrounding areas but could also cause residents nearby to file civil complaints to the extent of bringing construction to a halt. To deal with this issue, construction engineers have worked strenuously to develop low noise & low vibration pile methods. A noise & vibration-free screw concrete pile method proposed in this study is one of the successful outputs. It penetrates pile underground by rotating and pressing in body of the pile to avert noise and vibration while maximizing bearing capacity. A prototype of noise and vibration-free precast screw pile method was manufactured, which is not seen anywhere in Korea and elsewhere, and have undergone pilot tests twice to determine construction method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.5
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• pp.363-369
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• 2004

Vibration/noise analysis as well as strength of gear teeth, roller bearing life. joural bearing design are considered in order to develop the high-speed machine centrifugal pump which had a speed increaser. A Campbell diagram, in which the excitation sources caused by the mass unbalance of the rotors and the transmitted errors of the gearing are considered. shows that. at the operating speed. there are not the critical speed. A high-speed machine centrifugal pump was made in order to evaluate developed speed increaser. Also, strict API standard were introduced for reliability evaluation of developed speed increaser, and performance evaluation were carried out. The result that evaluation items about bearing vibration, shaft vibration, noise, and lubrication temperature were selected, and were tested. a high-speed machine centrifugal pump were able to know what were satisfied with API standard all.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.5
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• pp.317-322
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• 2002

A solution procedure of vibration and radiated noise of the plate covered with damping material has been studied. To predict the vibration level and the radiated noise level of the plate covered with damping material, FEM and BEM have been utilized, respectively. A property of damping material has been measured by using a composite beam. Two different kinds of measuring procedure for the composite beam have been introduced by comparing its characteristics. The numerical prediction of vibration level of the Plate covered with damping material has been proved with experimental data.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.5
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• pp.394-400
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• 2013

Underwater radiated noise is one of the important performances related to stealth of the naval vessel. However, the evaluation can't be performed frequently due to the cost. Therefore, the estimation method of the underwater radiated noise with average hull vibration is suggested in this paper assuming that the hull of the ship is infinite plate which consists of various unit plates. Through the experiment, the estimated noise is verified from the comparison to the measured data. In addition the difference of underwater radiated noise according to the operating equipments is estimated with measured vibration velocity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.159-160
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• 2014

The floor impact noise arising between upper and lower households in residential houses has been known as one of major causes worsening residential environment and still led to serious social troubles in a residential community. It is known that the heavy weight floor impact noise is induced by flexural vibration modes in the relatively lower frequency ranges. In this study, a procedure is examined to evaluate the relations between the vibration modes and the corresponding noise of the slab. In the process, for simplicity of the numerical analysis, it is assumed that the slab is simply supported plate-like structure and the acoustic mode formed in the lower room by acoustic boundary conditions is ignored.