• Journal of Biosystems Engineering
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• v.36 no.1
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• pp.1-8
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• 2011

Six models of operator seat supplied to local tractor manufacturers were tested in the laboratory in accordance with ISO 5007 and 78/764/EEC. No models out of the six met the allowable damping and transmissibility performance criteria of both ISO 5007 and 78/764/EEC. From the ISO criterion standpoint, one model failed in damping performance and 4 models in isolation performance. From the 78/764/EEC criterion standpoint, 4 models failed in damping performance and 4 models in isolation performance. However none of them failed in all of the criteria, either. Each model met the one acceptance criterion but failed in another. This indicated that operator seat must be improved to meet the current ISO 5007 or 78/764/EEC and the exposure limit value that will be enforced in EU tractor market from 2014 by EU Directive 2002/44 EC.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.558-567
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• 2011

One of the main objectives of noise control act is to define and ensure application and respect of noise exposure limits. Most advanced countries have prepared a legal framework for noise limits either by national laws, ordinances or municipal by-laws. A large number of advaced countries have adopted the $L_{eq}$ index for the main sources of noise (road, railway, industry). The exception is aircraft noise for which regulatory practice is highly disparate. These differences in the indices adopted, the periods and areas to which regulations apply, definitions of measurement conditions and ways in which noise levels are calculated make it difficult to compare the current advanced countries standards. This study presents the current noise abatement policy of the advanced countries and proposes the improvement of the current noise abatement policy of Korea to catch up with it of the advanced countries.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.2 s.107
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• pp.156-162
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• 2006

For the reduction and efficient management of railway noise, first of all prediction of railway noise is necessarily requisited. Many studies for prediction of railway nearby noise have been accomplished. But it is impossible to predict easily and exactly for the Korean Railway, because the acoustic powers for each rolling stock operated in Korea have not been built yet. So in this study, Prediction model equation for environmental noise for Korean rolling stock Saemaeul was suggested using SEL of engine and rolling noise component separately. Finally for the validation of prediction equation, the predicted result was compared to the measured.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.610-615
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• 2002

This study is to evaluate the risk perception of noise of the ground-crews in the Korean airbases who exposed to noise of jet plane. 1148 ground-crews and 231 pilots of 2 airbases participated in this study. The questionnaires of risk perception with visual analogue scale were completed by the participants. For comparison, the perception of other risks such as beef contaminated with dioxin, AIDS, lung cancer, otitis media, shigellosis, driving, drinking, and smoking were also included in the questionnaire of risk perception. The results of this study suggested the necessity of risk communication about noise and activation of effective hearing conservation program in the Korean air-force.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.138-140
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• 2014

The image quality of the color laser printer is highly related with the motion quality of actuators. However, the high precision system requires high production costs in general. The proposed design method in this paper improves image quality without increasing production costs. Using the synchronization method, time gap between exposure and transfer in organic photo conductive (OPC) drum and the period of driving gear revolution are synchronized. The proposed method is verified by computer simulations and experiment, and showed by printed images.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.885-887
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• 2014

Outdoor spaces in an apartment complex have been enlarged by the increased underground car parking. It has become accepted as important place for acoustic comfort of resident. This paper attempts to determine the noise exposure to the outdoor area in 21 apartment complexes built within 5 years. The results showed that the average noise level of outdoor area ranged from 37.6dB(A) to 67.2dB(A). And the percentage of areas below the noise level of 55dB(A) range 0.1% to 95.0%. The analysis on correlations shows that the traffic volume and building coverage have significant effects on noise level.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.7-9
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• 2014

An auditory experiment was conducted to establish annoyance criteria for floor impact noise in apartment buildings. Heavyweight floor impact sounds were recorded using an impact ball; the impact sound pressure level (SPL) together with the temporal decay rate (DR), which is quantified by the dB drop per second, was analyzed. For the experiment, A-weighted exposure levels of the heavy-weight floor impact sounds ranging 34~73 dB were evaluated at 3 dB intervals. Participants used a 7-point verbal scale to evaluate the level of annoyance from floor impact noise. The results show that the annoyance increases with increasing impact SPL and decreasing DR. Consequently, a classification and an acceptable level of floor impact sounds were proposed.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.388-392
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• 2003

In this study, various railroad geotechnical informations were standardized. The standardization was progressed by classifying the informations as basic properties, railroad vibrations and design plans. Basic informations included soil properties(27), dynamic property(1), geophysical prospecting(1), and elastic wave prospecting(4). Specification for 'human exposure to whole-body vibration' was used to construct the information of railroad vibration. And in the case of the information of design plan, the way to save by graphic files was chosen. Thus standardized informations examined their application by setting up database. Entity-Relation(E-R) model was used in the design of database and by this, the database system was constructed. This database system will be able to serve the performance enhancement of railroad system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.8 s.113
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• pp.789-796
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• 2006

The characteristics of the four standard floor impact sources (impact ball, bang machine, tapping machine, modified tapping machine) and a human impact source (jumping children) were investigated. First, the mechanical impedance of each source were evaluated. Then, the impact force exposure level of each source were measured. The results showed that fundamental frequency and impedance produced by the impact ball are the most similar to those of the human impact source. The frequency characteristics of the impact ball were most similar to those of jumping children. Consequently, the impact ball more accurately reproduces human impact compared to the other standard impact sources. Therefore, the impact ball should be considered as the reliable impactor in evaluating floor impact noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.808-811
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• 2005

To use the impact ball as a new standard floor impact source, the objective and subjective properties of the impact bali were investigated. The results showed that not only the objective properties of the impact ball such as the Impact force exposure level, mechanical impedance but also the psychological parameters were more similar to those of the human impact than the bang machine. In addition, most of the subjects chose the impact bail sound as the most similar sound to the human impact sound in the auditory experiment.