• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.12 s.105
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• pp.1327-1331
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• 2005

This Paper addresses what amount of whole-body vibration is exposed to Korean pilots of UH60 helicopters during their mission flight. To measure the expose4 whole-body vibration, the 12-axis whole-body vibration measurement system was used. It enables the direct measurement of whole-body vibration exposed from the body contact area consisting of the feet, hip and back. The measured 12-axis vibration signals were used to evaluate the vibration comfort level experienced by the pilots of UH60 helicopters. The evaluated vibration comfort level is found to be closeto 0.74-0.79m/s, which is equivalent to the semantic scale of 'fairly uncomfortable'. To assess the health effects of whole-body vibration exposed to Korean pilots of UH60 helicopters during their mission flight, the rms-based and VDV(vibration dose value)-based evaluation schemes, recommended by ISO 2631-1:1977, were exploited in this work. The evaluated results indicate that Korean pilots cannot avoid the fatigue-decreased proficiency limit after two-hour continuous flight. The whole-body vibration level exposed from the UH60 helicopters during continuous 10-hours mission flight is found to reach to the vibration exposure limit.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.04a
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• pp.29-33
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• 1996

This paper addresses a systematic way of understanding the transfer characteristics of whole-body vibration due to the external excitation. Amirouche's and Tamaoki's models are considered, whose analysis shows a new result that resonant frequencies related to the head vibration are well coincided with those of the body. This point reveals that the improvement of the ride quality of passenger cars can be achieved by isolating only external vibration components transfered to the body. Finally, this paper points out the limitation of previous whole-body vibration models, which gives the motivations of setting up more 'practical and generalized' whole-body vibration models of interests in this study.

• Journal of KSNVE
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• v.6 no.5
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• pp.625-633
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• 1996

This paper addresses a systematic way of understanding the transfer characteristics of whole-body vibration due to the external excitation. Amirouche's and Tamaoki's models are considered, whose analysis shows a new result that resonant frequencies related to the head vibration are well coincided with those of the body. This point reveals that the improvement of the ride quality of passenger cars can be achieved by isolating only external vibration components transfered to the body. Finally, this paper points out the limitation of previous whole-body vibration models, which gives the motivations of setting up more 'practical and generalized' whole-body vibration models of interest in this study.

• Journal of the Ergonomics Society of Korea
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• v.32 no.4
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• pp.381-387
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• 2013

Objective: This paper studies the method of measuring whole-body vibration in the car and terms associated. Background: Human exposure to vibration can be broadly classified as localized and whole-body vibration. The whole-body vibration affects the entire body of the exposed person. It is mainly transmitted through the seat surfaces, backrests, and through the floor to an individual sitting in the vehicle. It can affect the comfort, performance, and health of individuals. Method: Human responses to whole-body vibration can be evaluated by two main standards such as ISO 2631 and BS 6841. The vibration is measured at 8 axes - three translations at feet, 3 translations of hip and two translations of back proposed by Griffin. B&K's sensors used in this study are the 3-axes translational acceleration sensor to measure the translational accelerations at the hip, back and foot. Results: The parameters associated with the whole-body vibration in the car are frequency weightings, frequency weighted root-mean-square, vibration dose values, maximum transient vibration value, seat effective amplitude transmissibility, ride values and ride comfort. Conclusion: Studied the evaluating methods of vibration exposure and ride comfort. Application: Evaluation of whole-body vibration in the car.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.148-159
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• 2004

This paper discusses vibration mode of the drivesystem considered the vehicle body's dynamic characteristics to study the influence of the vehicle body's dynamic characteristics on the vibration mode of the engine mount system and the ride quality of a vehicle. The simulation model consists of the engine mount system, the powertrain and the rigid or elastic vehicle body. Variables used in this study are the stiffnesses of an engine mount system and the excitation forces. The Goals of the study are analyzing both the vibration transmitted to the vehicle body including the drivesystem and the influence of the vehicle body's dynamic characteristics on the engine mount system. The mode of drivesystems with a rigid and a elastic vehicle body was compared. From the result of the forced vibration analysis for the drivesystem with a elastic vehicle body, it is shown that the vehicle body's dynamic characteristics influence on the engine mount system reciprocally.

• Korean Journal of Applied Biomechanics
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• v.31 no.1
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• pp.59-63
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• 2021

Objective: Through comparative analysis of muscle activity for whole-body vibration, walking and running movements, it is to verify the training effect of whole-body vibration exercise in terms of amount of exercise and muscle activity characteristics. Method: Flat ground walking and slope walking (10 degrees) at a speed of 5 km/h, flat ground running and slope running (10 degrees) at a speed of 11 km/h for running were performed on treadmill, and squats were maintained at 12 Hz, 20 Hz, and 29 Hz conditions on Whole body vibration exercise equipment (Galileo). Muscle activity was analyzed through EMG analysis device for one minute for each condition. Results: The Anterior Tibialis and Erector Spinae show greater exercise effect in whole-body vibration than walking and running. The Rectus Femoris, Biceps Femoris, and Gluteus Maximus have the best effect of exercise in flat running. Whole-body vibration exercise showed greater muscle activation effect as the frequency increased, and exercise effect similar to walking during the same exercise time. Conclusion: The amount of exercise through Whole-body vibration exercise was similar to that of walking exercise, and the Anterior Tibialis and Erector Spinae shows better exercise effect than walking and running.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.93-99
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• 2002

Ride comfort, one of the most important performances of a car, is affected by vibration, noise, dynamic movement, and ergonomic factors. Among these factors, ride comfort vibration is heavily affected by the seat system, tire, suspension, and body structure. In this study, vibration characteristics of seat, tire, suspension, and body structure are analyzed. The vibration transfer function from the road input to the human body is also investigated.

• Korean Journal of Exercise Nutrition
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• v.13 no.2
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• pp.147-153
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• 2009

Effect of whole body vibration exercise on intracerebral hemorrhage in rats. Intracerebral hemorrhage is one of the most devastating types of stroke. This disease is known to cause severe neurological damage and also has a very high mortality rate. In the present study, the effects of whole body vibration exercise on memory capability and apoptotic neuronal cell death in the hippocampal CA1 region following intracerebral hemorrhage in rats were investigated. Intracerebral hemorrhage was induced by injection of collagenase into the hippocampal CA1 region using a stereotaxic instrument. The rats were divided into 5 groups: the sham-operation group, the hemorrhage-induction group, the hemorrhage-induction and 8 Hz vibration exercise group, the hemorrhage-induction and 16 Hz vibration exercise group, and the hemorrhage-induction and 24 Hz vibration exercise group. The animals in the whole body vibration exercise groups received whole body vibration at 8 Hz, 16 Hz, and 24 Hz, respectively for 30 min once a day during 14 consecutive days. In the present results, the apoptotic neuronal cell death in the hippocampal CA1 region was significantly increased following induction of intracerebral hemorrhage, resulting in memory impairment. Whole body vibration exercise suppressed hemorrhage-induced apoptosis in the hippocampal CA1 region. This suppressive effect of whole body vibration exercise also alleviated hemorrhage-induced memory impairment. Here in this study, we have shown that whole body vibration exercise inhibited intracerebral hemorrhage-induced apoptotic neuronal cell death and thus facilitated recovery of brain function following intracerebral hemorrhage.

• International Journal of Control, Automation, and Systems
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• v.4 no.6
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• pp.714-724
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• 2006

In this note a method of designing optimal vibration control based on Haar functions to control of bounce and pitch vibrations in engine-body vibration structure is presented. Utilizing properties of Haar functions, a computational method to find optimal vibration control for the engine-body system is developed. It is shown that the optimal state trajectories and optimal vibration control are calculated approximately by solving only algebraic equations instead of solving the Riccati differential equation. Simulation results are included to demonstrate the validity and applicability of the technique.

• Journal of Biomedical Engineering Research
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• v.40 no.6
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• pp.235-241
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• 2019

The purpose of this study was to investigate the effect of the body temperature peripheral circulation with vibration shoes in healthy 10 adults. The magnetic vibration device with non-electric power was mounted in the midsole of the vibration shoes. The experiment was divided into two groups: vibration shoes and no vibration shoes. Subjects were randomly selected and measured body surface temperature by digital infrared thermal imaging (DITI) and non-invasive capillaries change by nailfold microscope (NFM). After walking in a treadmill for 15 minutes at 4.0 km/h speed wearing normal shoes or vibration shoes, DITI and NFM were measured. The walking with vibration shoes showed the body surface temperature shift from the proximal to the distal. In addition, the diameter of the nailfold capillary in the vibration shoes group was thicker and clearer due to the increased blood flow than that of the no vibration shoes group. The vibration shoes are easy to apply to anyone who can walk because it can give vibration stimulation by walking without additional time, cost, and effort in daily life. Further studies are needed to explain the physiological effects of vibration frequency and intensity on the long-term perspective of target subjects resulting from vascular dysfunction.