• Journal of the Ergonomics Society of Korea
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• v.32 no.4
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• pp.389-396
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• 2013

Objective: The ride qualities of the six passenger cars were evaluated in 4 subjects on the highway and uneven road. The relation between vibration with driving velocity and driving posture were also investigated separately. Background: Ride comfort plays an important role in the vehicle design. Vibration is the one of the principal components associated with ride comfort. Method: The acceleration of the foot, hip and back were measured using B&K accelerometers in this study. The velocity of the passenger cars was maintained at a constant speed of 80km/h on the highway and 40km/h on the uneven road. For evaluating the effects of driving velocity and driving posture on vehicle's vibration level, separate experiments were performed on the highway with 5 different vehicle speeds and 5 different backrest angles, respectively. Results: The overall ride value of the luxury car showed the best result while the smaller car showed the worst value on the highway. On the uneven road the overall ride value level was increased 75~98%. All the vehicles had the SEAT value less than 1. Faster the velocity lowers the SEAT value. The ride quality in terms of vibration gets worst when the backrest angle increased. Conclusion: The smaller car had a first mode at the higher frequency and showed higher vibration level. SEAT value was mostly affected by the seat property not by vehicle. We ranked the luxury car seat had a best vibration reduction quality than others based on SEAT values. When the driving velocity increased, the overall ride values were increased proportionally and the SEAT values were somewhat decreased. Application: Evaluation of whole-body vibration in the passenger car.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2179-2184
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• 2008

The ride comfort is more important according to train speedup. Generally it is defined as the vehicle vibration. There are many studies on evaluation method of ride comfort for railway. But the ride comfort for Korean high speed train(HSR 350x) has been assessed by statistical method according to UIC 513R. In this paper, the ride indices, which are measured in the Korean high speed train, have been analyzed and reviewed by appling the statistical methodology such as t-test, variance analysis(ANOVA) and regression analysis.

• 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.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.2
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• pp.57-65
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• 2016

The suspension system of a subway vehicle is composed of $1^{st}$ and $2^{nd}$ springs. The suspension system is the most important parameter in determining the vibration ride comfort. If the $1^{st}$ suspension spring is designed as a spring with strong stiffness to improve the running stability at high speed, it causes vehicle vibrations. In this paper, by testing and analyzing changes of the characteristics of Chevron springs, which have been the primary suspension springs used for about 20 years, we study how changing the characteristics affects vehicle acceleration and ride comfort. The lateral and longitudinal vibrational ride comfort index levels were lower than the vertical ones. Therefore, as increasing the stiffness of Chevron springs has the greatest effect on the vertical vibrational ride comfort index level, a countermeasure for vertical vibration reduction is needed when the stiffness increases owing to aging. Finally, maintenance guidelines, including the replacement time for the Chevron rubber, were proposed based on these findings.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.6
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• pp.102-109
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• 1998

As the fundamental study of an active suspension system, computer simulation is performed using a quarter model. Design data for the development of active suspension system are presented through performance estimation of active control laws in the time and frequency domain. The verification of compromise between ride quality and handling characteristics is carried out.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.33-40
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• 1999

Park and Ride(P＆R) system has not implemented it's intended object in Seoul metropolitan area, still less it didn't impact on diminishing the ridership of urban railway. This paper is focused on analysis of Park and Rail ride user survey of travel behavior and trip chain. We propose the ideal location of P＆R in Seoul and stratagies to increase the utilization of P＆R.

• Journal of Industrial Technology
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• v.20 no.B
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• pp.105-113
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• 2000

Air springs are now widely used in bus or truck suspensions due to their advantages over conventional metal spring as coil or leaf springs. Air springs have soft spring rates, which give better ride quality, and additional leveling system provides constant ride height and maintains almost same vertical natural frequencies. A mathematical model of an air spring suspension system with height control system is constructed and dynamic responses of the suspension system are investigated in the light of leveling valve motion characteristic, vertical motion natural frequency. Also, using a full vehicle model, handling characteristics of an air spring suspension is studied and the results are compared with real test results, which shows good agreements.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.272-277
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• 2007

Generally railway vehicle runs on the rail with endless interaction between wheel and rail. Irregularity of rail causes the periodic motion of the vehicle. In association with this motion, the design of vehicle would be carried out in order to avoid the resonance between car-body and bogie. It may be seen that the first vertical bending mode of car-body contributes considerably to the vertical ride comfort level. In this paper to know the effect of the car-body first vertical bending mode on vertical ride comfort, the mode has been considered with dynamic model. I-DEAS program was used to get the car-body first vertical bending mode and VAMPIRE program was used to analyze ride comfort index(Wz) with FE interface file.

• Archives of design research
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• v.15 no.3
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• pp.5-14
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• 2002

The amusement design of a large amusement park, including theme park, largely consists of attraction design, the main facilities, and auxiliary facilities design. The purpose of this study was to discuss the physical motion characteristics of major ride, a recently highlighted representative ride attraction, modern people's thirst for stronger stimuli, and some of the right future directions for amusement design. In theme park, there is an growing trend for rides, especially major rides, to be more thrilling, and Newton's Law motion is basically applied. The rides we can often see provides a thrilling experience that is different from that offered by vehicles we use everyday, due to a variety of speed change, namely of acceleration. Every entertainment facilities, including ride attractions, are externally cutting edge with the use of new technology. but internally, poor theme or concept not only makes it difficult to function properly as attraction but poses a severe threat to theme park survival itself. Theme park will be able to exist as a comprehensive entertainment entity, when attractions are designed to have a perfect harmony among story, method and environment with cultural universality.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1557-1558
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• 2011