• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.316-323
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• 2003

The gear system is commonly applied in the marine propulsion shafting system using the diesel engine with the power take off/in system and it also is necessary to reduce propeller revolution increasing the propulsion efficiency. The diesel engine has the advantage more than other thermal engines in high thermal efficiency and mobility. But the large vibratory torque which induced by higher combustion pressure is transmitted to these gears. In this paper, the surface durability and bending stress of gear system considering vibratory and transient torque is evaluated by ISO and AGMA regulation. And the influence of these in gear design is investigated with the theoretical analysis and onboard measurement result of torsional vibration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1126-1131
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• 2002

Offices and other multipurpose buildings commonly have suspended ceilings installed over room dividing wall. But Korean Standards don't include any code on test methods and test facility of the suspended ceiling system. Therefore, test methods and test facility from ISO or ASTM have been used for evaluating sound performance in domestic so far. In this study, every regulation from ISO, ASTM, especially for airborne sound insulation against suspended ceiling system, is analyzed in order to apply to establishment of Korean Standards on test methods and test facility of suspended ceiling system and materials.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1194-1197
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• 2006

Recently, international standard for measurement of sound absorption in a reverberation room has been amended. In the revised version, temperature, humidity and air pressure conditions are strictly restricted and also the concrete procedures are presented to reduce the differences in test results by adding inspection of diffusion, measurement uncertainty etc. In this paper, the systematic tests are conducted based on the inspection guide of diffusion defined by ISO 354 and the effects of diffusers on the measurement of sound absorption ratio are considered. As a result, we perceived that the averaged sound absorption ratio in mid and high frequency range is expected to measure around $0.05{\sim}0.1$ higher in high sound absorption material. Therefore, as for the reverberation room for measurement of sound absorption, we need to take into consideration not only the spatial standard deviation of sound pressure mandated by ISO 3741, but also, inspection regulation of diffusion showed by ISO 354.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1198-1201
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• 2006

ISO 140-1 recommends installing diffusing elements in the room if there are large variations of the sound pressure level caused by strong standing wave. Also it requires that reverberation time should not be long or short. In accordance to this regulation, we adjusted the reverberation time in the range of $1{\sim}2$ sec by using 4 types of diffusing elements. This paper demonstrates how to balance the reverberation time in the range of $1{\sim}2$ sec by using several types of diffusing elements.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.255-260
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• 2003

The regulation for floor impact sound level is expected to be amended to 50㏈(L$\_$i, Fmax, AW/) and below in heavy-weight impact sound and 58㏈(L'$\_$n, AW/) and below in light-weight impact sound in Korea. The purpose of this paper is to analyze the influence factors of floor impact sound levels in apartments. The influence factors were air pressure of bang machine, height of microphones, data acquisition rate, etc. The air pressure range of bang machine were from 2.2 Pa to 2.6 Fa. Five microphones were installed at a height of 0.5m, 0.7m, 0.9m, 1.2m, 1.5m or 1.7m from floor level. The floor impact sound level was varied about 1-3㏈(L$\_$i, Fmax, AW/) in heavy-weight impact sound according to the influence factors.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.796-799
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• 2005

In 2005, a regulation on the heavy-weight impact sound was released, which restricted concrete slab thickness of standard floor to 210mm. To reduce heavy-weight impact sound, damping materials and structural reinforcement system have been proposed. In this study, the effect of compressive strength on the heavy-weight impact vibration and sound were investigated. FEM analysis was conducted for the 34PY apartment with different concrete strength (210, 350, 420kg/cm$^2$). In addition, apartment floors with different concrete strength were constructed and the floor impact vibration and sound were measured. Results of FEM analysis and measurement show that the resonance frequency of concrete slab was increased by the increment of concrete strength. However, floor impact sound pressure level did not decrease because the nor impact vibration and sound pressure level in 63Hz band increased.

• Journal of KSNVE
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• v.8 no.6
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• pp.1009-1014
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• 1998

유럽 18개 국가의 표준제정기구가 회원으로 구성되어 있는 유럽 규격제정 위원회(CEN：Comite europeen de Normalisation 또는 European Committee on Standardization)는 유럽 내에서 시판. 사용되는 모든 제품이 만족해야 할 규격 또는 규제안(regulation)을 제정하는 일을 담당하고 있다. 이들이 제정하는 규격의 기본적인 내용은 국제규격이나 각 나라의 규격과 대동소이하지만 그 내용에 있어서 구체적인 제품을 지정하기 때문에 보다 세분화되어 있으며 상업적인 성격을 띈다는 측면에서 ISO, DIN. BS등의 국제표준규격과 성격을 달리한다고 할 수 있다 특히, 이 위원회에서 공동으로 제정된 사안은 각 회원국에서 수정 없이 그대로 국가 인증규격으로 사용하므로 산업계에서는 상당한 영향력을 지닌 기구라고 할 수 있다.(중략)

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.156-156
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• 1999

This paper describes the characteristics and the criteria of electrical environmental effects produced from power system especially transmission line. Audible noise radio and TV interference, electric and magnetic inductions which are main items for optimal conductor selection as well as major contributors to the community complaint of electrical environmental problem, are surveyed and studied comparing with the criteria or the environmental protection regulation of domestic and foreign countries. As a result a domestic criteria of electrical environmental on power system was suggested.

• Journal of IKEEE
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• v.15 no.3
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• pp.218-226
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• 2011

In this paper, the leaky electric field intensity of outdoor CATV facilities on CDMA mobile service band defined in technical regulation related with CATV is investigated if appropriate or not. From experimental and theoretical analysis results, Maximum allowable power level of CATV leakage should be -110dBm/1.23MHz. Also, the CATV leakage intensity thresholds, which may not nearly give an impact on the uplink performance of CDMA mobile base station for outdoor background noise of -100~-80dBm/1.23MHz to be measured in outdoor environment, couldn't conform to the current CATV technical regulation. Therefore, the leakage intensity in the current CATV technical regulation is rated as a too much low level in view of an overly worst case.

• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.110-117
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• 2004

The environmental-related disputes and claims are steeply increasing recently. Among them the number of disputes and claims on noise and vibration incurred in the process of construction is more than $85\%$. Since those disputes and claims cause cost overrun and or penalty and bad impression for the construction company, it is necessary to develop a systematic management method for solving them. This study presents a environmental management structure based on the examining many kinds of environmental-related laws including 'The Act on Regulation of Noise and Vibration' furthermore, through analysing various dispute and claim cases, and surveying literatures we suggest environmental study noise and vibration management method using for the preconstruction phase, the construction phase and the post construction phase, respectively.