• Journal of the Ergonomics Society of Korea
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• v.30 no.5
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• pp.605-611
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• 2011

Objective: The aim of this study was to investigate the influence of seat heights for optimizing the ingress/egress performance in the elderly people. Background: Recently elderly users have been increasing in number and the ease of ingress/egress of the vehicle becomes an important issue. Method: Seven elderly subjects participated in this study(age: 71.7${\pm}$3.6yr, height: 167.7${\pm}$5.4cm, weight: 68.1${\pm}$11.5kg). Each subject performed the sitting and rising task from comfortable seated position on the chair under the following conditions: (1) with a lumbar support and (2) without a lumbar support. We measured EMG activities of seven muscles(tibialis anterior, soleus, gastrocnemius, vastus lateralis, rectus femoris, biceps femoris and erector supinae) and ranges of motion in lower limb during sitting and standing from three different heights (400mm, 500mm and 600mm from ground) of slide-up seat. Results: Muscle activities and angular movements of hip and knee joints during standing-up and sitting-down with a high seat height(600mm) were reduced mean 30.4% in extensor muscles, 57.11% in flexor muscle, 18.74% in erector muscle and 31.0% in joints compared with a low seat height(400mm). Conclusion: Muscle activities and joint movements in hip and knee were reduced when rising/sitting from a high seat height(600mm) compared with a low seat height(400mm). Application: This study can be used to design vehicle that are easy to get in and out of by older peoples with or without impairments.

• Journal of Auto-vehicle Safety Association
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• v.7 no.3
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• pp.7-13
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• 2015

Occupant protection performance in frontal crashes has been developed and assessed for mainly front seat occupants over many years, and in recent years protection of rear seat occupants has also been extensively discussed. Unlike the front seats, the rear seats are often occupied by children seated in rear-facing or forward - facing child restraint systems, or booster seats. In the ENCAP, child occupant protection assessments using 18-month-old(P1.5) and 3-year-old(P3) test dummies in the rear seat have already been changed to new type of 18-month-old (Q1.5)and 3-year-old(Q3) test dummies. In addition, ENCAP are scheduled with the development and introduction of test dummies of 6-year-old (Q6) and 10.5-year-old children(Q10) starting 2016. In KNCAP, Q6 and Q10 child dummies will be introduced in 2017 as well. Automobile manufacturers need to develop safety performance for new child dummies closely. In this paper, we focused on Q6 and Q10 child dummies sitting in child restraint system. Offset frontal crash tests were conducted using two types of test dummies, Q6 and Q10 child dummies, positioned in the rear seat. Q6 and Q10 were used to compare dummy kinematics in rear seating positions between Q6 behind the driver's seat and Q10 behind the front passenger's seat. The full vehicle sled test results of both dummies were conducted with different restraint systems. It showed that several injury and image data was collected as the result of the full vehicle sled test. Based on the results of these investigations, this paper describes which factor is most important and combination is the best performance when evaluating rear seat occupant protection for Q6 and Q10 child dummies.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.994-995
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• 2014

Supporting stiffness of seats is an important component affecting dynamic characteristics cognized by a passenger. To analyze dynamic characteristic of a seat for vehicles operating on various road conditions, the seat vibration from road irregularity should be understood and compared. In this study, the seat is analyzed as distributed supporting system. The dynamic stiffness is measured using masses. The characteristic of the seats is analyzed by measuring distributed dynamic stiffness. The distributed dynamic stiffness of the seat is estimated on various locations and the effects of each component such as spatial distribution, compression level and vibration amplitude are analyzed. The influence of seat cover, elastic support and flexible polyurethane foam on the measured stiffness was analyzed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.2
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• pp.130-136
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• 2018

This study develops a seat with electric motor technology for a one-ton grade commercial vehicle. While applying electric motor technology, the FMVSS 210 seat frame strength test is also conducted to examine the product's weak parts. The seat frame strength test used the FMVSS 210 test standard and the ANSYS program was used to simulate the test and identify weak parts in the deformation and strain values. The test results showed that the cushion frame and slide rail connection bracket were fractured at loads of about 10,000 N. Similarly, the maximum stress and strain values in the bracket were obtained in the simulation results. On this basis, it was evaluated that the connection part bracket was a considerably weak part in the case of the first model, and changing the shape of the bracket and reinforcing the strength were required. In addition, the seat belt anchorage test results and simulation results were compared to assure their validity. In the comparison results, the error for each is about 5-10%. Therefore, the simulation performed in this study is considered to have produced reasonably accurate results.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.3
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• pp.151-160
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• 2014

In this study, the effect of the automotive haptic-seat technology which can transmit the driving information by the vibro-stimulus from the seat was investigated to overcome previous system's limitation relied on the visual and audial method and to help handicap driving. A prototype haptic seat cover with 30 coin-type motors and driver module were developed for this sake. In an experiment of seat vibration stimulation being performed under virtual driving situation by targeting the elderly aged over 65 years old, average score of test subjects for total vibration recognition was 3.5/4 points and recognition rate of 87.5% was represented. In addition, a result that all the test subjects totally recognized overspeed warning signal of 4 times was represented. As a result of statistical analysis for vibration recognition score by each group depending on TMT score, a significant difference was not found and a result that tactile function of which vibration is recognized even by the aged whose visual, perceptional function is declined showed an equal ability was obtained.. In this study it was shown that the seat vibration stimulus could be used to transfer the old drivers' information while driving.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.1
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• pp.16-26
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• 1998

The major effective factors on the ride quality of a vehicle are the vibration and noise of the engine and drive system. Engine contributes about 80% of the vibration and noise in the vehicle, and exciting forces of the engine are transmitted onto the vehicle frame through the engine mount. This paper studies the vibration reduction of a vehicle through the improvement of the engine mount. A computer program for optimal design is developed and the engine mount conditions are optimized to reduce the WRMS of PSD of acceleration at the driver's seat, which are caused by the exciting forces at the idle speed. Design variables are selected as the stiffness, mount angle and the location of the engine mount rubber. It is shown through computer simulation that the PSD of acceleration at the driver's seat can be improved by redesigning the engine mount system.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1736-1740
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• 2003

There have been various studies to find out the correlation between subjective and objective evaluation ride comfort in vehicle. To be proper, subjective evaluation considers the signal pattern of vibration generated by vehicle. In this study, driving test is carried out to extract the correlation between subjective evaluation by subjects and vibration signals measured on the seat when a test vehicle is passing over test bumpers, which have two sorts of width change and height change respectively. A unique reference bumper is used to be compared with the relative comfort of test bumpers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.961-962
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.138-145
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• 2005

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.973-974
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• 2010