• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.600-601
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• 2013

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.6
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• pp.515-520
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• 2010

The noise map has been applied to predicting the effect of noise and establishing the noise abatement measure for several years overseas. However the introduction of the noise map in Korea is at the initial stage. Thus, we surveyed the several prediction models for road traffic noise used in EU, and the method of applying the noise map in noise impact assessment. In order to improve the noise impact assessment we have to apply the noise map, and propose the guideline of predicting the road traffic noise. We intend to obtain coherency and accuracy of prediction results. As a result of this study, we know that the prediction guideline is an essential prerequisite in order to predict the unified and accurate road traffic noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.992-995
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• 2006

In this Paper the noise characteristics of KTX are analyzed in order to study the interior noise mechanism of KTX in slab tracks, which has become an issue since the commercial operating in 2004. The analysis of the interior noise of KTX in tunnel with concrete track shows sharply increased noise level in the range of 80Hz that is the natural frequency of the KIX carbody. The frequency characteristics of noise and acceleration levels of KTX in tunnels are compared to understand the interrelation between the noise inside the vehicle and outside the vehicle in the slat track tunnel. As a noise abatement method, the mud-flap was modified with intend to reduce the noise outside gangway and the interior noise inside the passenger compartment ultimately. The effect of this mud-flap modification on the interior noise is introduced and discussed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.557-563
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• 1997

In order to satisfy the regulations concerned with the noise emission of fork-lift trucks and thereby increase export to the western countries, a noise reduction technique should be developed in the early design stage. In this paper, several noise sources are identified using the sound suppression method and sound intensity measurement, and their contributions to the sound levels at the operator's ears and at the distance of 7m from the vehicle are studied. For each of the major noise producting components, noise abatement alternative are suggested and their effects are analyzed.

• The Korean Journal of Air & Space Law and Policy
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• v.14
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• pp.305-330
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• 2001

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.4
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• pp.35-41
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• 1998

The workplace noise environment is composed of three basic elements : manufacturing (in a generic sense) facilities, office areas, and the community around the facility. Work must be done by all employees , and this involves communication within a variety of locations within the facility ; areas may be extremely noisy, moderately noisy, or quiet, such as an office. At the same time, the facility should not be annoying to the community. In this paper, the workplace environmental noise of office areas in power plant are studied. Turbine generator in power plant generates the noise of 90∼95 dB(A) in the frequency range of 1 kHz, which may cause occupational hearing loss. By abatement method which are made of isolation material and distance damping effect, about 29.5 dB(A) reduction has been obtained in office areas of the Power Plant . But, the workplace environmental noise of office areas in the power plant is not suited to office's purpose.

• Journal of the Korean Society for Advanced Composite Structures
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• v.7 no.1
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• pp.19-24
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• 2016

Most of the soundproof tunnels generate significant discharge noise through their inlets and outlets so that the length of the tunnel has been extended frequently than required to minimize the effect on such discharge noise. Thus, in this paper, we investigate reduction capability of discharge noise from the sound proof tunnel installed with lateral sound-absorbing panels on the partitioned truss members in the longitudinal direction of the tunnel. In conclusion, noise field analysis results shows that the sound proof tunnels with lateral sound-absorbing panels have an effect on discharge noise abatement and thereby tunnel's length reduction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1615-1620
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• 2000

The extensive increase of the rotating speed of HDD (hard disk drive) has improved the performance of HDD. One of drawbacks, however, is that it increase noise level. For the systematic noise control of HDD, it is important to know the way in which each source of HDD contributes to resulting noise. A conventional method for contribution analysis by using statistical information, however, is not proper for HDD. This paper reviews the conventional method, and explains the reason why the method is not proper for HDD, even though it is possible to find the number of independent sources by using statistical information. This paper also shows an experimental result for the identification of the number of independent sources of HDD.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.2
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• pp.99-104
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• 2013

Assessment of noise exposed population is to check the environmental noise level and social influence in order to reduce the risks such as annoyance and disturbance that are generated by environmental noise. Also, this method suggests the preferential noise abatement policy and action plan by accurately finding the area that the noise causes harmful effect to human health. Recently, a noise map, which can predict noise in comprehensive areas, is used for the assessment of noise exposed population, breaking from the methods using existing measures. In particular, countermeasure for the noise can be considered more effectively by using assessment methods of noise exposed population for specific noise levels, areas, and building types which are the main input factors in noise maps. In this study, assessment methods of noise exposed population by using 2 dimensional noise map are compared with those by 3 dimensional noise map.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.1-5
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• 2003

The random pulse width modulation(RPWM) on the noise and vibration abatement in inverter-fed induction motor drive is presented. This paper describes a RPWM technique based on space vector PWM strategy for shaping the switching noise spectrum in such a way it can merge with the natural system noise. To verify the validity of the proposed RPWM scheme, the experiment based on the TMS320 C3l microprocessor was executed. Finally, the simulation and experimental results will be given to demonstrate the effectiveness of the proposed RPWM technique.