• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.770-773
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• 2006

In order to remove the whine noise which has high frequency spectrum related to the uniform tinning space in concrete pavements, randomization study of the tinning space has been done. One of the random tinning space proposed by the authors in the previous study has been applied to the certain region of tile Daegu-Pohang high way construction. In this study, the vehicle interior noise and vibration have been measured in the proposed random tinning road and compared with the data measured in the uniform tinning road. The results show that the magnitude of the peak spectrum is decreased by 18dB(A), and the overall noize level decreased by 4dB(A).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.974-977
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• 2007

본 연구에서는 건설 공사소음 예측 및 가설방음벽 설계를 위해 개발한 공사장 소음예측 프로그램에 대해 소개하고자 한다. 또한, 건설장비가 운영되는 동안 이격거리별 소음측정을 수행한 후 측정결과와 해석결과와의 비교검토를 통해 개발 프로그램의 타당성을 검증하고자 하며, 상용되고 있는 소음해석 전용 소프트웨어를 이용해 다양한 경우에 대한 소음해석을 수행한 후 해석결과를 개발 프로그램의 해석결과와 비교함으로서 개발 프로그램의 타당성을 검증하는 것을 본 연구의 목적으로 한다.

• Special Issue of the Society of Naval Architects of Korea
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• 2005.06a
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• pp.97-106
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• 2005

According to the trends of construction of large size vessel with high power the natural frequencies of the bending modes of propeller blades have been lower than the past. Therefore, it is expected that the noise and vibration problems of the marine propeller are frequently occurred. As main issue of the propeller noise and vibration problem, the cavitation noise and singing noise due to the flow induced excitation of the bending modes of propeller blade in the high frequency range has been studied by the hydrodynamic researchers in the view point of the excitation force reduction. In this paper, the vibration mode characteristics of propeller with a large diameter in very large vessel are investigated by the vibration analysis of the finite element method using MSC/Nastran and the vibration measurement by the impact test on the propeller blade. According to the results, the natural frequencies of various blade bending modes in water entrained condition could be estimated from the natural frequencies taken by the measurement and free vibration analysis in the dry condition, and it could be estimated how the high frequency noise such as singing is generated from the blade bending modes.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.659-662
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• 2009

Railway has been pointed to the efficiency of transportation, rapid transit, and comfortable train ride. the construction of railway near the downtown area and station building are increasing for maximization of utilization and convenience. but the heavy of transportation and rapid transit lead to increase noise and vibration. the noise and vibration of railway may cause the civil appeal, decline in the serviceability and insufficiency of environmental standard. In this study, floating slab system which is one of the solution to avoid noise and vibration in railway has been introduced, and analyzed floating Slab Track into arrangement of reduction material of vibration. As a result of analysis, It was estimated the bearing installation though slab have not a negative factor and terminal arrangement of reduction material of vibration have advantage for static behavior.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.30-37
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• 2009

In doing the foundation work in the downtown, the popular complaints by means of Noise and vibration have been became heavy burden. Therefore, the noise & vibration-free screw PHC pile method will contribute to the foundation work by removal of the popular complaints and improvement of the constructability. In this paper, the load bearing capacity and displacement characteristics of the noise & vibration-free screw PHC pile were analyzed. The noise & vibration-free screw PHC pile's behavior was better well than the existing PHC pile's one.

• Journal of the Korean Geotechnical Society
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• v.29 no.4
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• pp.5-11
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• 2013

In close to downtown construction, the main problem is complaints caused by blasting vibration and noise. To reduce blasting vibration and noise, deck-charge blasting method using electronic detonator can be more secure because there is no cut-off problem. And in this method it is possible to blast in horizontal direction. In this study, the efficiency of horizontal direction deck-charge blasting method using electronic detonator is compared to that of the existing blasting method. And the possibility of applying the construction site is evaluated. As a result, the reduction of blasting vibration, noise and secondary breaking has been determined, as well as large-scale blasting in the vibration criterion can be regulated by the overall increase in blasting efficiency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.37-45
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• 2003

The diesel engines was invented a little more than one hundred years ago and has ever since been developed for better fuel economy, increased power and smaller size. Thanks to its fuel economy, the diesel engine is today the dominating prime mover in many applications, such as smaller power plants, commercial ships, trains, trucks, buses and all kinds of mobile construction machinery. As engine for passenger cars, the diesel engine is steadily increasing its share of the market. However, its versatility and, consequently, large prevalence have led to environmental demands to its exhaust emissions, noise and vibration. This paper deals with the noise aspects of diesel engine designs of the so-called low speed two-stroke type installed in most large ships.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.11
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• pp.1153-1160
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• 2004

In contemporary society, vibration and noise in the road nearby buildings have become social problems as vehicles operation has increased. Especially. in the case of the building used to art performance, available suitability of the building is tested by the indoor noise class. Therefore, the Purpose of this paper is the measurement of the structure-borne noise of Seoul Art Center nearby Umyeonsan tunnel and analyzing the effects of countermeasure to it. To measure the effects of countermeasure, not only structure-borne noise is measured, but also the vibration is measured, before and after the construction of Pavement using pad and porous asphalt. Consequently, the sound pressure level in art center 1st floor is reduced after mat pavement method, structure-borne noise that was high In 25Hz wide-band before pavement decreased regardless of experimental vehicle's velocity Using porous asphalt pavement the noise was reduced about 3 dB(A).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.480-483
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• 2007

Recently, many apartment houses were built in nearby road and railway. Road traffic noise level and railroad traffic noise level are important factors on apartment houses inhabitant's acoustic comforts. The measurement methods which noted by Ministry of Construction & Transportation, Ministry of Environment and Korean Industrial Standard are used for measurement of exterior noise at apartment houses. The purpose of this study compare the noise level characteristic by the measuring methods and evaluating methods. The results show that road traffic noise in the daytime appeared by not greatly noise level difference by the measuring method and evaluating methods. But railroad traffic noise appeared by greatly the noise level difference by the equivalent noise level(1hour) and continuous time.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.390-393
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• 2005

In this study, examined heavy-weight floor impact sound to rahmen structure(steel reinforced concrete structure) and bearing-wall structure(box frame type structure) that have slab thickness of 4 form at a standard laboratory through noise and vibration measured. The results of ANSYS modeling of structures was predicted that the nature natural frequency increased according to change of thickness of each slab by finite element analysis, and acceleration value decreased. Rahmen structures compares with bearing-wall structure, nature frequency was predicted low. Measurement results of natural frequency and acceleration level for structures at a standard laboratory, tendency department such as ANSYS modeling appeared. Rahmen structures appeared that reduction effect is less in Acceleration level and heavy impact sound transmission level comparing with bearing-wall structure.