• 한국산업보건학회지
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• 제33권2호
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• pp.103-114
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• 2023

Objectives: This study was conducted to evaluate hand-arm vibration (HAV) exposure levels due to the use of power hand tools and to evaluate the determinants in the automobile assembly process. Methods: The exposure level to HAV was evaluated for 30 work lines in five assembly processes (body, engine, chassis, door, and design) that use air-powered tools and battery-powered tools and operate in circulation for two hours. The 2-hr equivalent energy vibration acceleration, A (2), of the task was measured. The 8-hr equivalent energy vibration acceleration, A (8), was estimated in consideration of the number of tasks that can be performed per day by each process. In addition, a survey on the working environment was conducted with workers exposed to vibration. Results: The geometric mean of the HAV exposure level, A (2), for a total of 30 tasks was 2.51 m/s², and one case was 10.30 m/s², exceeding TLV (2hr). The HAV exposure level of A (8) was evaluated from 1.03 m/s² to 5.36 m/s². A (2) showed a statistically significant difference (P<0.01) for each process, and the chassis process (GM=3.90 m/s²) was the highest. The larger the tool size and the longer the tool length, the higher was the vibration acceleration when using a battery-powered tool than an air-powered tool (P<0.01). Battery-powered tool users showed higher dissatisfaction on all items than did air-powered tool users. Conclusions: As a result of this study, it is necessary to implement a program to reduce the HAV exposure levels.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.251-254
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• 2005

In this study vibration transmissibilities of the selected anti-vibration gloves were measured, and the measurement uncertainty was estimated. Since human factors such as palm size, gripping condition and dynamic properties of the hand-arm effect the measurement a lot, it is necessary to know ow much the uncertainty is. This study takes the measurement procedure suggested in ISO 10819. Three subjects Joined at each test and each anti-vibration glove was tested twice per a subject. Average and standard deviation of vibration transmissibility were calculated and uncertainty of them were estimated at 95% confidence level.

• Structural Engineering and Mechanics
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• 제83권5호
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• pp.681-692
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• 2022

The vibrational response of the two bones in a Volleyball player's arm under ball impact is conducted. The two bones in hand, Ulna and Radius, are modeled as two cylindrical shells. The formulations associated with the shells' vibration are obtained using the energy method. Then, the results are extracted with the aid of the two-dimensional form of DQM in conjunction with Runge-Kutta. The results are validated by means of a published paper. Lastly, the role of parameters in determining vibrational frequency as well as deflection is explored through parametric studies. It was shown that the impactor speed and the time of the impact could be essential factors in determining the vibration behavior of the bones. This work can be used in the further investigation of the behavior of bones and physiological structures.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.227-230
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• 2000

This paper introduces international and Korean standards related to human-related vibration. It reviews recent standards of ISO and KS and compares them. This comparison and analysis reveals that the current direction and activity in ISO is in progress and presents logical ways of updating Korean standards in the future. Finally, the current activity of upgrading Korean standards in the Korean TC 108/SC4 is introduced.

• 한국컴퓨터정보학회논문지
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• 제22권6호
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• pp.149-156
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• 2017

In this paper, we propose to enhance a Physical working conditions to decrease absence from work. we demonstrated the correlation of worker's absence with various environmental factors in workplace by surveying 6,962 workers. As result, first, concerning exposure to physical work factors, most of them complained of vibration, and concerning exposure to improper working posture, most of them complained of repetitive arm and hand motions. Second, the absence experience had correlations with age, monthly income, smoking, number of employees, long term working, and shift work, and of the physical factors, hand vibration, noise, high temperature, low temperature and improper working posture had correlations with physical pain posture, movement of people and carrying heavy materials. Third, experience of exposure to hand vibration, noise and low temperature of the physical factors had impact on absence, and of the improper working posture, physical pain posture and carrying heavy stuff had impacts on absence. Through this study, it was found that of the work factors of Korean workers, physical factors and improper working posture had impacts on absence. The results of this study confirmed that physical factors and inappropriate working posture among work factors influenced the absenteeism. Therefore, it is required to improve the work environment regarding physical risk factors and prepare a systematic management plan.

• 대한인간공학회지
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• 제32권4호
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• pp.309-319
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• 2013

Objective: The aim of this study is to review and summarize human vibration measurement process, and necessity and methods of frequency weightings for human vibration. Background: Prolonged human exposure to hand-arm vibration and whole-body vibration can result in a range of adverse conditions and the development of occupational diseases such as vibration white finger. For preventing these adverse effects, it is important to correctly apply human vibration measurement process. Method: This manuscript was based on the review and summary of mechanical and human vibration relevant texts, academic papers, materials obtained through web surfing. Results: This manuscript summarizes human vibration measurement process described in ISO standards and relevant texts. The sensitivity of the human body to mechanical vibration is known to be dependent on both the frequency and direction of vibration. To take this into account, varying frequency weighting functions have been developed, and RMS frequency-weighted accelerations are used as the most important quantity to evaluate the effects of vibration on health. ISO provided nine frequency weighting functions in the form of curves and tables. Researches on frequency weightings are focused on development and validation of new frequency weightings to truly reflect the relationship between vibration exposure and its adverse effects. Application: This would be useful information for systematically applying human vibration measurement and analysis process, and for selecting appropriate frequency weighting functions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.65-69
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• 2004

The small form factor optical data storage devices are developing rapidly nowadays. Since it is designed for portable and compatibility with flash memory, its components such as disk, head, focusing actuator, and spindle motor should be assembled within 5 m thickness. The thickness of focusing actuator is within 2 mm and the total working range is $+/-100{\mu}m$, with the resolution of less than $1{\mu}m$. Since the thickness is limited tightly, it is hard to place the yoke that closes the magnetic circuit and hard to make strong flux density without yoke. Therefore, Halbach array is adopted to increase the magnetic flux of one side without yoke. The proposed Halbach array type focusing actuator has the advantage of thin actuation structure with sacrificing less flux density than conventional magnetic array. The optical head unit is moved on the swing arm type tracking actuator. Focusing coil is attached to swing arm, and Halbach magnet array is positioned at the bottom of deck along the tracking line, and focusing actuator exerts force by the Fleming's left hand rule. The working range and resolution of focusing actuator are analyzed with FEM and experiment.

• 한국직업건강간호학회지
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• 제13권1호
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• pp.19-29
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• 2004

Purpose: This study was conducted at small-to-medium-sized manufacture enterprises less than 300 employees. Method: For 167 workers in 12 small-to-medium-sized manufacture, we examined the self-recording questionnaires about general characteristics, health characteristics, occupational characteristics and subjective musculoskeletal symptoms designed by NIOSH. Result: Related factors of upper limb musculoskeletal symptoms were found in using of the PC except work, the speed control at working and inappropriate positions for neck, and that using of the PC except work, the degree of intensity at working and the speed control at working for shoulder, and that the degree of intensity at working, the speed control at working, inappropriate positions and excessive workforce for arm/elbow, and that the degree of intensity at working, the speed control at working, inappropriate positions, excessive strong and vibration for hand/wrist/fingers. Conclusion: As a result of multiple logistic regression analysis, musculoskeletal symptoms of neck were influenced by use of the PC except work, household work, and the speed control at working, symptoms of shoulder by using of the PC of except work and the degree of intensity at working, symptoms of arm/elbow by the speed control at working, and symptoms of hand/wrist/fingers by the degree of intensity at work and excessive workforce.

• 대한의용생체공학회:의공학회지
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• 제41권6호
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• pp.264-271
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• 2020

The purpose of this study was to investigate the effects of active vibration exercise of upper limb on physical capacity index (endurance, grip strength, balance, and flexibility) and vasomotor index (capillary length and body surface temperature) in middle aged women. 20 participants randomly divided into two groups: vibro-swing exercise (VSE) and non vibro-swing exercise (NVSE). Subjects in each group measured the 30 second arm curl test, hand dynamometer, one leg standing test, back scratch test, nail fold capillary microscope (NFM), and digital infrared thermal imaging (DITI) before and after exercise. The results showed that active vibration exercise of upper limb with vibro-swing equipment increased the endurance, balance ability, and the capillary length. In addition, changes in body temperature immediately after exercise were predicted to affect vasomotor. Active vibration exercise of upper limb has the advantage of being able to exercise anywhere regardless of the location by inducing different frequency changes in movement of various ranges and velocity. For this reason, the combination of vibration and active movement can be expected the physiological effects when producing exercise programs for middle aged women.

• 대한인간공학회지
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• 제32권4호
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• pp.321-331
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• 2013

Objective: The aim of this study is to review the literatures on the regulation, standard and guideline for the human vibration in Korea and other countries. Background: This review can be used to prevent various diseases caused by the human vibration as a basis for the development of the policy. Results: In Korea, the general employers' duties related to human vibration are set forth the Health Measures(Article 24) in the Occupational Safety and Health Act. And then an employer shall take measures to protect the health of the workers concerned by improving other working conditions relating to working hours for the vibration prevention measures referred to in Article 24 of the Act. The European Union adopted a Directive in 2002 on minimum requirements for the health and safety of workers exposed to vibration. New Regulations on Vibration at Work will be introduced in Great Britain on 2005 to implement the Directive. In the U.S., both ANSI and ACGIH adopted the ISO standard for measurement and suggested exposure action and limit values. In Japan, the Ministry of Labor decided that the vibration syndrome among operators of rock drills and riveters etc. could be included in an occupational disease(1947). In addition, ISO standard was based on proposals and draft documents of many countries such as U.K, Japan and European, etc. Conclusion: In Korea, Occupational Safety and Health Act prevent vibration to health, but do not include exposure limits. It is therefore important to consider the new duties regarding to vibration risks added to the general duties.