• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2436-2441
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• 2015

BSR noise from automobiles is largely issued in recent as an emotional quality. This study describes the two test methods for determining BSR noise occurred in automotive seat system. First, the sine sweep test is found to be an effective excitation method for determining BSR noise with high frequency. Second, BSR operation test is introduced in such a way that BSR noise during operation of seat height system is measured by several accelerometer at each 800 cycles until 6400 cycles. The periodic noise signal is captured during one cycle after many cycles of operation. Two test method presented in this paper can be analyzed more efficiently BSR noise of the seat.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.542-548
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• 2003

This paper describes an overall Noise Assurance Plan(NAP) in the project for developing a new rolling stock. In this paper, the procedure for implementing noise control activities for each development stage on the basis of the NAP is also described. The NAP was developed by KITECH(Korea Institute of Industrial Technology) and ODS(${\Phi}$degaard ＆ Danneskiold-Samsoe in DENMARK). Generally, the main objective of NAP is that noise assurance plan applies to the establishment of organization and personnel's roles and responsibilities, set-up of overall procedure and internal audit program. Here, a few comments are made to the deviations of the actual procedure(G7 Project) relative to the suggested NAP presented. The major difference between the suggested NAP and the actual procedure was the late involvement of the noise consultant resulting in suggestions for design improvements could not be implemented due to the advanced stage of the design. Similarly, the important task of preparing sub-supplier specifications was performed. The proposed NAP will be an efficient tool for noise management in the R＆D project for new rolling stock. Specially, in case that several companies and institutes are involoved in the R＆D team

• Korean Journal of Health Education and Promotion
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• v.19 no.3
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• pp.107-120
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• 2002

There has been a rapid industrial progress in Korea since 1962 by the success of 5-year economic development plan, and the number of industrial work has also made a rapid increase. Consequently, the management of the occupational health for the purpose of promoting the health of industrial workers and improving the working environment is badly needed in these days. Health services on industrial noisy environment have been provided only for noise-induced hearing loss management until now. But gradually, modem diseases and death have come to be related to the stress and mental health, therefore noise-induced mental disorder, like a stress became very important. Thus, this study has been carried out to analyze the relationship between workers' stress symptoms and the perceived working environment and the perceived working conditions. This study included 786 industrial workers selected from II factories in Buchun. The results were as follows: 1. For demographic characteristics, most of the workers were males(75.7%), the 20～29 years old were 33.8% and those who graduated from high school were 56.1%. The workers whose monthly income ranged from 700,000 to 1,500,000 won were 37.9% and who has a religion were 49.0%. 2. For occupational characteristics, workers who had worked 5～10 years in the factories were 35.8%. Those who felt much for them workload were 42.7% and who worked more than 8 hours a day were 73.7%. Those who were dissatisfied with their pay and job were 51.1 % and 31.2%. The workers who responded ventilation condition of their worksites were bad were 50.4% and the dissatisfied with working environment of their worksites were 43.8%. 3. For the noise exposure level in worksite, workers who were exposed to 70∼90㏈ were 37.4%, 90∼100㏈ were 25.2% and 50∼70㏈ were 18.8%. 4. Workers∼ stress symptoms were significantly related to marital status and their monthly income(P〈0.05). Workers who were single and had lower monthly income showed higher PSI(Psychiatric Symptom Index) scores than those who were married and had higher monthly income. Higher PSI scores were also significantly related to the night-work, workload, dissatisfaction with their job, and bad relationship with their bosses or co-workers. 5. The higher noise exposure level in worksite from 80㏈ was, the more severe stress symptoms including PSI subparts were reported; Anxiety, Anger, Depression, and Cognitive disorder symptom(P〈0.001). 6. According to the results of stepwise multiple regression analysis, factors affecting workers' PSI scores were noise exposure level in worksite(R2=0.150), relationship with coworkers, amount of workload, monthly income and relationship with bosses orderly and the total R2 of this 6 factors was 29.7%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.175-182
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• 2021

As road noise became an issue, low-noise pavement (LNP) has emerged. The noise difference from general asphalt pavement (GAP) is a measure to explain the noise reduction of LNP. On the other hand, even for GAP, noise varies with the performance years (PY) and pavement condition. This study evaluated the representative noise value (RNV) by the speed and PY of GAP. Sections of 49selected from the National Road Pavement Management System, and the noise was measured at speeds from 50km/h to 80km/h at every 10km/h using the Close Proximity Method (CPX). Because the noise immediately after construction differed from the other, it was treated separately, and some outliers were removed. The noise increased with increasing PY. In addition, the noise increase by speed showed a reliable trend at all noise levels. The RNV for each speed and PY was obtained through analyses of the PY and speed. The average noise difference between the initial construction and the six-year-paced pavement was approximately 6dB. When evaluating the noise reduction of LNP, it is necessary to use RNV rather than the noise of old pavement. The RNV of GAP is necessary for a relative comparison with LNP and studying the road noise characteristics for each GAP type.

• Journal of the Korean Society of Safety
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• v.11 no.4
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• pp.34-41
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• 1996

The purpose of this study is to obtain an effective enclosing method for noise reduction of press machine operating in a manufacturing company located in Taegu region. Noise level of the machine is about 95～120 ㏈ which is higher than legal standards by industrial safety and health law. In this study, two experiments were conducted to achieve the above purpose. In the first experiment in which the effects of three independent variables-type and depth of sound-absorbing materials, and depth of air space-on noise level was investigated, it was found that depth of sound-absorbing materials and air space was significant at $\alpha$ = -0.01. In the second experiment studying relationship between depth of sound-absorbing materials and air space and noise level, it was shown that noise level lowered as depth of sound-absorbing materials and air space became thick. Based on these results, two alternatives of enclosing method adequate for the selected company's noise characteristics were suggested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.755-759
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• 2012

In this paper, it is about random number generator, which is based on hardware is utilized in medical science and game area. The Intel presents guideline of security level about hardware based true random number generator. At hardware based random number generator, the various test items, that are included in test suits as NIST statistical test, FIPS140-1, is applied. In this paper, it experiments about degree extent of randomness variation from filter scheme effects, which is applied in output stream of hardware noise source.

• Journal of Korea Society of Industrial Information Systems
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• v.2 no.2
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• pp.219-228
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• 1997

The Fano metric is the maximum likelihood decoding choice for convlutional code for binary symmetric channel. The Fano metric assumes that it has previous knowledge of channel error probability. However, the bit errors in real channel occur in bursts and the channel error probability can not be known exactly. Thus, the Fano metric is not the maximum likelihood choice for bursty-noise channel. In this paper universal metri which dose not require the previous knowlege of the channel transition probability is used for sequential decoding. It is shown that the complexity of the universal is much less than that of the Fano metric bursty-noise channel, since it is estimated on a branch by branch basis.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.5
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• pp.383-392
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• 2013

Taguchi method is a technique widely used in industries to attain a reliable quality even under existence of various noise variables. Basically, it relies on the interactions between the controllable and the noise factors. Under insignificant interactions between the design parameters and noises, the effectiveness of Taguchi methodology will be doubtful. Furthermore, existence of strong interactions among controllable factors may undermine the power of Taguchi approach. An abundant crop may be expected by a well planned Taguchi approach. A well designed set of experiments is one of the important prerequisites for its successful result. For this, we must have a clear understanding on strengths and weaknesses of Taguchi methodology together with a sound knowledge on the applicable system. This study provides some insights on Taguchi approach based on two case examples of one successful and the other unsuccessful. Eventually, this research aims to facilitate deeper understanding and right application of Taguchi methodology in industries.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.150-155
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• 2008

Dynamic characteristics of a wrist power transmission examine closely with mass property, to present a model which is able to induce the vibration is ultimately the purpose. A robot wrist power transmission for analysis model gets the mass property through the approach to be the experimental. A bearing equivalent stiffness which supports the axis and a gear contact equivalent stiffness are determined by the simplicity analysis model compared the result of the experiment. We calculate the vibration tendency of the robot wrist power transmission by an analysis tool which is called the RecurDyn. We compared it with a signal analysis experiment's which a robot operation happens which is based on the ambient noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.243-246
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• 2004

The dynamic characteristic of a wrist power transmission examine closely with mass property, to present the model which induce the vibration is ultimately the purpose. A robot wrist power transmission for analysis model got the mass property through the approach to be the experimental. A bearing equivalent stiffness which supports the axis and a gear contact equivalent stiffness are determined by the simplicity analysis model compared the result of the experiment. We calculate the vibration tendency of the robot wrist power transmission by an analysis tool which is called the RecurDyn. We compared it with a signal analysis experiment's which a robot operation happens which is based on the ambient noise.