• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.125-131
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• 2000

This study was performed to evaluate the whole-body vibration and occupational noise for excavator drivers. Measurement, evaluation and assessment were based on the ISO 2631 and OSHA. Average vibration level was 0.65m/$s^2$(z axis) for breaking work and 0.36 m/$s^2$(z axis) for excavating work. Vibration levels during breaking work exceed the health guidance caution zone and this means that the drivers are exposed to potential health risks. Average daily noise exposure level was 86.4 dB(A) for breaking work and 84.6 dB(A) for excavating work.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.768-771
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• 2002

국외 환경 소음과 진동은 이미 세계보건기구(WHO)와 UN산하 환경기관에서 선언한 바와 같이 “전세계인의 문제”(“global issues”)로 분류 인식하고 있으며, 이들 문제점들에 대한 접근은 선진국들의 국민 복지정책의 가장 핵심적 요소로 관리하고 있다. 예를 들어, WHO가 출판한 공중소음에 대한 지침서［1］, 그리고 유럽공동체의 전문가 그룹이 작성한 보고서［2］들은 최근의 환경소음에 대한 새로운 접근의 필요성, 새로운 측정 및 평가 방법, 그리고 인체에 미치는 복합적 영향들의 새로운 평가 기법 개발, 그리고 환경 개선을 위한 장기적 계획과 실천 방안들을 구체적으로 제시하고 있다.(중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.241-245
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• 2003

When considering the effects of whole-body vertical vibration, it is valuable to have an understanding of the mechanical characteristics (mechanical impedance and apparent mass) of the body. This paper addresses experimental results carried out to investigate the characteristics of apparent masses fer 41 Korean. The apparent masses of the seated human body in vertical direction were measured during different experimental conditions, such as vibration excitation level (0.5-2 ms$\^$-2/ r.m.s). frequency range (1-50Hz), and upper body posture (relaxed, normal and backrest-upright). We showed the average of all subjects and all conditions and compared the results with ISO5982/DIS (2000).

• Journal of Preventive Medicine and Public Health
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• v.28 no.4 s.51
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• pp.765-771
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• 1995

This study was performed to investigate the possibility of temporary threshold shift (TTS) of vibration sense could induced by exposure to high-frequency vibration or by work position taking by dentists in drilling or polishing. The vibratory perception thresholds (VPT) of 28 healthy men were measured on the index fingertip pulp of dominant hand at 250 Hz. The vibrating tool used in test was a low-speed handpiece of 34,000 rpm. For the TTS test, the dominant hand was exposed to high-frequency vibration and to work position for five minutes, respectively. The VPTs before and after vibratory exposure were $23.5{\pm}3.5dB,\;30.8{\pm}4.2dB$, respectively and VPT after work position was $23.7{\pm}4.6dB$. The difference between before and after vibartory exposure was statistically significant (p<0.001). The correlation of height, weight and BMI with baseline VPTs was not statistically significant. Also, there was no difference of VPTs by smoking. These results suggest that high-frequency vibration from dental handpieces might cause the impairment of vibration sensation.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.4
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• pp.284-290
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• 2015

Road traffic noise is closely related with urban forms and urban components, such as population, building, traffic and land-use, etc. Hence, it is possible to minimize the noise exposure problem depending on how to plan new town or urban planning alteration. This paper provides ways to apply for urban planning in consideration of noise exposure through road traffic noise estimation for alteration of small-scale urban form. Spatial autoregressive model from the former study is used as statistical model for noise simulation. The simulation results by the spatial statistical model are compared with those by the engineering program-based modeling for 5 scenarios of small-scale urban form alteration. The error from the limitation of containing informations inside the grid cell and the difficulties of reflecting acoustic phenomena exists. Nevertheless, in the stage of preliminary design, the use of the statistical models that have been estimated well could be useful in time and economically.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.6_spc
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• pp.674-679
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• 2016

According to the conventional studies on the noise and cardiovascular effect, railway noise is better associated with hypertension and adverse cardiovascular events than road traffic noise. But the underlying mechanisms remain unclear. We investigated the hypothesis that exposure to acute railway noise would the unfavorable effect of cardiovascular and autonomic system in healthy young subjects. Using a randomized, sham-controlled cross-over design, ten subjects were assigned to receive either an exposure to high speed train noise (84 dB) for 30 minutes or a control condition (non noise), separated by two days. Blood pressure, heart rate, augmentation index and heart rate variability as indices of cardiovascular and autonomic system function were measured at baseline, during, and recovery from two trials. The results show that exposure to acute railway noise significantly increased diastolic blood pressure and augmentation index, which may cause of adverse cardiovascular effects.

• Journal of Preventive Medicine and Public Health
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• v.14 no.1
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• pp.75-80
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• 1981

Due to rapid industrialization and economic development, the occupational diseases have appeared as one of the social problems in Korea. Up until now little has been known about the prevalence rate, predisposing factors and symptomatology of the occupational disease due to localized vibration in Korea. The researcher intends to investigate the prevalence rate and affecting factors of the occupational disease due to localized vibration among rock-drillers in the anthracite mines. A total of 135 rock-drillers were interviewed and examined from May 15th to 31th, 1980. The results were revealed as follows; 1. The prevalence rate of the vibration syndrome among rock-drillers was 12.6%. 2. The latent period of the vibration syndrome was 6.8 years. 3. The prevalence rate of the vibration syndrome was not significantly different between smokers and non-smokers. 4. With the increase of total vibration exposure time, the prevalence rate of the vibration syndrome increased also. 5. The average vibration sensation threshold was high (6.4dB) in stage 1 of the vibration syndrome and low (-0.6dB) in stage 0. 6. The average pain sensation threshold was high (4.4g) in stage 1 of the vibration syndrome and low (2.5g) in stage 0.

• Journal of Biosystems Engineering
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• v.27 no.4
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• pp.273-282
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• 2002

This study was intended to measure and analyze hand-transmitted vibrations from cultivator in idle and operation modes for three different types of field works. Based on this analysis a time for the white finger syndrome to appear on 10% of the operators was estimated assuming that their daily exposure is 3 hours. The 4 methods to reduce the hand vibration were also proposed and compared with each other. The results of the study were summarized as follows : The highest vibration level was recorded during trenching operation, resulting in a total average vibration of 11.5 m/s$^2$. Followings were 7.6 m/s$^2$ during rotary tillage and 7.0 m/s$^2$ for weeding. When exposed to these levels of vibrations three hours a day, the white finger syndrome is likely to appear in 4 years for trenching, 6.2 years for rotary tillage and 6.8 years for weeding operations. Isolation of hand vibration performed by a rubber pad, anti-vibration gloves, a handle anti-vibration device and engine mounts were respectively 15.7%, 16.5%. 26.1% and 27.0%, resulting in most effective methods of the handle anti-vibration device and engine mounts. A better performance of about 33.9% was achieved when both the handle anti-vibration device and engine mounts were used.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.82-87
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• 2003

Nuclear fuel with a big slenderness ratio is susceptible to flow-induced vibration under very severe conditions of high temperature, high flow and exposure to irradiation in nuclear reactor. The fuel assembly should, therefore, be designed to escape any resonance due to the vibration during the reactor operation, in particular, in case of the design changes. In addition, the amplitudes due to the grid vibration, the fuel rod vibration and the fuel assembly vibration should be minimized to reduce the grid-to-rod fretting wear. Fuel assembly vibration tests in air at room temperature and in water at high temperature have been performed to investigate fuel vibration behaviors. The frequency and damping during the test in air have been compared to those in water. Through the hydraulic test, the advanced assembly has been evaluated not to be susceptible to any resonance. In addition, the test data from the tests can be used to make fuel model and to evaluate grid-to-rod fretting wear.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.911-916
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• 2005

Noise map is a presentation of existing data or predicted noise situation in terms of noise indicator. However, it has shortcoming for assessing the number of people exposed, or the number of dwellings affected to any relevant limit values of noise level in certain areas. In this study, so called over-ride value noise mapping is proposed to make up for the shortcoming by using over-ride function of object-oriented programming and it is to show the guard of the area where it is satisfied the standard of option, or it is not satisfactory. Over-ride value noisemap data is combined with topography layer, population and house statistics, and GIS space statistical analysis. The over-ride value noise mapping can also he applied to make the road traffic noisemap, the railroad noisemap, the aircraft noisemap, and the industrial site noisemap This can express noise damage information more exactly.