• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.938-943
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• 2003

In accordance with the tendance to construct high-rise apartment buildings, the elevators tend to high speed up and to the drive more frequently. So, the problem of vibration and noise produced by the operating elevator has been treated as an important subject all the more. In this research, the actual levels of vibration and noise which generated and transmitted by the elevator operation in apartment buildings were measured and these characteristics were analysed to examine the countermeasures to be able to reduce the these vibration and noise level, and to design the several vibration and noise control.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.488-493
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• 2001

In accordance with the tendance to construct high-rise apartment buildings, the transporting elevators tend to speed up to 90-105m／min and to drive more frequently. So, the problem of noise produced by the elevator operation has been treated as an important subject. In this research, the actual conditions of noise and vibration which generated and transmitted by the elevator operation in apartment buildings were measured and analysed. And the several noise and vibration control design which helps reduce noise were examined.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.509-513
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• 2013

There are so many types of construction equipment. Excavator is one of typical construction equipment which is working under the tough and severe environments. It's important for engineers to design CE components by the vibration durability point of view. Traditionally, two typical vibration durability methods to verify the durability of components. The first is experimental method which is using the vibration durability test bench. But experimental approach on vibration durability is needed a lot of cost and time. The second is analytical method which is using the vibration durability analysis such as Dirlik, Stainberg, Lalanne and others methodologies. The one of main advantages on vibration durability analysis can reduce the cost and time. We present a vibration durability analysis process and methodology on the guardrail system in excavator.

• Journal of Environmental Impact Assessment
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• v.17 no.6
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• pp.381-391
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• 2008

The instances of the damage to livestock are increasing with frequent environmental disputes on the noise and vibration. This study analyzed 134 open cases dealing with the environmental disputes on livestock damaged by noise and vibration, and being intervened by National Environmental Dispute Resolution Commission. The environmental disputes on the noise and vibration account for 86% of all the disputes, and cases of the consequent damages to livestock have increased. As shown in the 134 cases, pig is the most lethal livestock attacked by the noise and vibration. During last 10 years, 89% of the noise damages hurting the livestock resulted from the noises pertaining to construction and 58% was due to the noise damages from the road constructions. The noise levels in the range of 70~80 dB(A) and the vibration levels of 70~75 dB(V) caused most of the disputes. The average rate of reimbursement for the livestock damages for the last 10 years was higher than the average rate of reimbursement of the total disputes intervened by National Dispute Resolution Commission.

• Journal of Environmental Impact Assessment
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• v.22 no.4
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• pp.369-379
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• 2013

Noise and vibration problems at the construction site, expansion of construction scale and frequency of urban construction is increased, has given the damage to local residents. Also, the result of civil complaint about noise and vibration that occurred in 2011 was 56,244; it is showing an increasing trend of more than 4% annually. In particular, the construction noise and vibration, the civil complaints of around construction site accounts for 64.6%(36,353), are harmful to the tranquility of living environment. As a result, the government has managed to strengthen the regulatory standard of construction noise (65dB(A), Day-time) from 2011. However, the regulatory standard of construction noise and vibration does not meet and also complaints related the construction noise and vibration not decreased. Because the management system can be applied to the construction site is insufficient and a shortage of manpower. In this study, investigated the status and problems of the regulatory standards related to construction noise and vibration, we propose an efficient management plan of construction noise and vibration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.530-533
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• 2005

Recently, modern reciprocating air compressors tend to be smaller and lighter. But, as the development of performance, they have many problems for noise and vibration. For this reason, many researches are processing for the reduction of noise and vibration by arranging cylinders with V/W type. Especially, noise and vibration problems of reciprocating air compressor cause a rotating unbalance of crankshaft, so it needs a change of crankshaft parameters appropriately. Hence in this study, we changed crankshaft parameters to solve the rotating unbalance and compared results in order to verify the noise and vibration reduction between new and original air compressor. According to modify a crankshaft parameter, the improvements of noise and vibration were showed results of spectrum measured at selected points of the air compressor crankshaft housing and sound intensity contours measured at a belt left side, table that figure out characteristics of noise. Furthermore, we analyzed objective sound quality metrics with recording data of systems. The results showed that, the new design has improved the level of the first harmonic of vibration displacement, noise and objective sound quality metrics.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.1
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• pp.3-9
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• 2009

This paper presents the reduction of acoustic noise generated by electromagnetic force in an induction motor of the electrical forklift. After summarizing the electromagnetic excitation forces due to the interaction between the stator/rotor slot permeance and the stator winding magnetomotive force, the effects of the electromagnetic force on the noise and vibration of an induction motor are analyzed. In order to experimentally identify the noise sources of the motor, the signal analyses for noise and vibration are performed by using waterfall plots of noise and vibration spectrums. It is found that severe noise and vibration are caused by the electromagnetic force when the mode number of the excitation shape for a stator is low. Furthermore, it is verified that the motor noise is amplified if the excitation frequency of the electromagnetic force coincides with one of the natural frequencies of the stator. It is experimentally demonstrated that this severe noise can be considerably reduced by structure modifications. Finally, some design guidelines are suggested to develop an induction motor with a low level of noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.829-835
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• 2001

The sources of wayside noise for the high speed train are the aerodynamic noise, rolling noise and power unit noise. One of the best ways to control the wayside noise is to analysis the noise level. In this paper, we measure the wayside noise and the vibration of the rail/sleeper for Korean Train Express (KTX) and compare with the results for the conventional train. The measurement results for KTX show that the characteristics of the noise and vibration are different from the conventional train and the rolling noise and power unit noise are the major sources.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.480-485
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• 2002

The overall noise reduction was compared in regard to the vibrational characteristics of floor impact noise in a multi story residential building which has several noise reduction treatments. The vibration through its structural elements such as wall, floor and ceiling and sound emitting were investigated for each insulation treatment. It was found that, in case of heavy-weight impact noise, the vibration energy is emitted mostly from ceiling, but for the light-weight impact noise, most of the energy comes through ceiling and walls. That is, the vibration of a ceiling is the main factor that determines the frequency characteristics of the transmitting noise to lower floors.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.269-274
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• 2007

With the importance of comfortable environment, research about noise reduction of construction is consisting much. If construction receives the input force, noise will be generated thereby. We must predict vibration and noise characteristic to reduce structured borne noise, and construction which become a basis of such research is plate. In order to predict the radiating noise from the vibrating surface. It is required to know the velocity distribution of vibration surface exactly. It is good to use bead for reducing vibration and noise of plate. In this study, we have analyzed structure-borne noise of plate with bead and compare with plate that there is no bead about equal exciting force.