• Journal of Auto-vehicle Safety Association
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• v.7 no.1
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• pp.13-19
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• 2015

Recently, Child safety has become one of the issue with Q10 dummy representing large child. The objective of this paper was to evaluate performance of three child restraints system (backless booster, high-back booster and without booster) by changing D-ring location in the rear seat. Sled tests were carried out with a Q 10 in 64km/h frontal impact. Before the dynamic sled tests, we assessed dummy positioning with difference in CRS types and height adjustment positions. Dynamic sled test results indicated that there is different performance of CRS types and belt routing. These test results will use as base line data for development CRS safety performance for Q 10.

• Journal of Biomedical Engineering Research
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• v.32 no.3
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• pp.191-197
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• 2011

Lifting chair is a typical assistive product to aid for standing up and sitting down for persons with disability. It is particularly useful for the elderly persons whose muscular system is weakened by degenerative joint disease. This paper describes biomechanical assessments of lifting chair with hip-up function. In experiments we measured 3D motion and electromyographic(EMG) signal on the femoral muscle when subject performs the standing motion on the predetermined seat height. Based on assessment of the standing motion, we select the hip-up angle as 15 degrees to cover the relative femoral angle when EMG peak value is appeared. Using an implemented prototype lifting chair with hip-up function we perform standing experiments with five subjects. The experimental results show that the lifting and hip-up functions are effective to assist for standing up motion with less muscle force.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.373-378
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• 2012

The purpose of this study was to develop an electric riding machine for cycle fitting to control riding posture easily, to measure frame size quantitatively, and to overcome disadvantages of the traditional systems. The electric riding machine consisted of actuator, load controller, and display & control unit. The actuator unit by BLDC(BrushLess Direct Current) motor drives the saddle height up and down, the crank forward and backward, the handlebar up and down, and the handlebar forward and backward. The load controller unit controls loads by Eddy current controller with electromagnet and aluminum circular plate. The display & control unit consisted of frame size controller and display panel which shows top tube length(485~663mm), head tube length(85~243mm), seat tube length(481~671mm), and seat tube angle($62.7{\sim}76.4^{\circ}$). The range of frame size control for developed electric riding machine did not have difference compared to traditional commercial systems, but quantitative and precise control with 0.1 mm length and $0.1^{\circ}$ angle was possible through digital measurement. Unlike traditional commercial systems, frame size control was possible during riding through motor driven method, thus fitting duration decreased. It is necessary for further improvement to have feedback from users. It is believed that developed electric riding machine can help to develop domestic fitting system.

• Journal of the Ergonomics Society of Korea
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• v.25 no.3
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• pp.25-32
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• 2006

As national income increases, consumers began to place a great deal of weight on products or quality of their life. They would like to have products which are more convenient to use and could meet their emotional desire in addition to its basic functional requirements. An automobile is one of the transportation system for human beings and the factor such as safety or environmentaly-friendly is regarded as important things resulting from it's popularization. In fact, domestic design technology leaves much to be desired compared with excellent manufacturing techniques. For this reason, some problems, like lowering of usage, could be caused by introducing technological data as it is from overseas. A survey of domestic car users has found that the most preferred condition (step height) is 460~495cm when they get in and out of their car. Men use their visual information and then get in the car, taking motion fit for each condition when automobile condition is changed. In other words, men get in cars actively within the range of conditions used for this study. These results were found from a motion study, when getting in a car, and checking the possibility of getting injury in accordance with the change of condition as well.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.102-106
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• 2012

The purpose of this paper is to study the failure cases in relation to system of Air Bag in vehicle happened in the field. In the first example, it was separated the soldering parts connected the wire pin between air bag module and clock spring of air bag. Whenever the pin shake by the car's vibration, the driver verified the malfunction phenomenon appeared air bag warning lamp on instrument panel in front of driver's seat. in car inside room. The second example, it verified the warning lamp lighting phenomenon of air bag by produced the circuit plate non-contacting of single an element in air bag electronic control unit. The third example, it verified the light of air bag warning indicator lamp by separated with soldering parts connecting inner pin and resistance terminal of seat belt pretensioner using passenger seat. The fourth example, when the passenger car crash a back of truck, the former bumper get jammed under the latter as the roof height of car low less than that. Therefore, the impact of Car's collision verified that don't transfer with body frame of vehicle because of no attachment impact sensor in it.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.446-452
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• 2020

As the use of children's school buses increases, accidents caused by the negligence of school bus drivers and ride carers have also increased significantly. To prevent such accidents, the government is coming up with various policies. We propose an accident prevention and safety management system for children's school buses. Through this system, bus drivers can easily check whether each child is seated and whether the seat belt is used, so it is possible to quickly respond to children's conditions while driving. With the ability to recognize faces by analyzing camera images, children can use a seat belt that is automatically adjusted to their height. It is therefore possible to prevent secondary injuries that may occur in the event of a traffic accident. In addition, a sleeping child-check system is provided to confirm that all children get off the bus, and a text service is provided to inform parents of their children's locations in real time. Based on Raspberry Pi, the system is implemented with cameras, pressure sensors, motors, Bluetooth modules, and so on. This proposed system was attached to a bus model to confirm that the series of functions work correctly.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.1
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• pp.59-67
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• 1992

The duration of raising seedling of infant rice seedling(IRS) in machine transplanting is 8 to 10 days. This experiment was conducted to investigate the minimum duration of IRS's raising seedling and its method by the combination of several treatments such as plant growth regulator, root-break-seat and temperature. The rice seeds of Hwaseongbyeo was soaked in the solution of metalaxyl for 24 hours at room temperature. Metalaxyl (25% wettable powder), a fungicide, was used in 1, 000 times dilution as a promting substance on the root-mat formation of IRS. The application of fungicide in the nursery soil for the controlling of damping-off and physiologyical seedling rot was omitted due to the metalaxyl seed-soaking treatment. Seeding rate was 220g per seed tray (30$\times$60$\times$3cm). To promote the root-mat formation of IRS, the sheets of polyethylene vinyl and absorptive paper were placed bottom the seed tray. The root-mat formation of IRS was promoted at higher temperature and longer duration of raising seedling. The metalaxyl-treated seeds markedly increased the root length and rooting activity of IRS as compared with the control, thus the root-mat formation was excellent. The absorptive paper with polyethylene vinyl as root-break-seat showed a better root-mat formation compared with control, polyethylene vinyl, alone. The minimum duration of raising seedling of IRS was 5 days after sowing based on the root-mat formation and seedling height under the condition of metalaxyl seed treatment, absorptive paper with polyethylene vinyl as a root-break-seat and the raising seedling temperature 30/2$0^{\circ}C$ (day /night).

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1996.11a
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• pp.42-48
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• 1996

Glare phenomenon by sun's altitude and strong sunlight make a much visual handicap. And so, it reaches to unreadable situation although enough illumination in the fore site student of a window site and passage site. In school student seat arrange in the order of their height. So, cause the eyesight acuity according to distance is different, eyesight of backseat's student drop 1.0 and less in spite of 1.0, a learning effect reduces rather then that of the fore site student for site and Passage sitestudents. Therefore. in school, the conclusion's alteration of school structure, position's alteration and material quality's improvement of blackboard are needed, should be local lighting in blackboard. Therefore, we think that in other in improve the effect of lesson by the student, the student seats are not given by uniform disposition in the order of their height but change by a specified period.

• The Journal of Korean Physical Therapy
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• v.25 no.6
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• pp.386-392
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• 2013

Purpose: This study aimed to verify the impact of the time that the sitting posture is maintained on changes in muscle performance and head alignment. Methods: The subjects of this study were healthy adults aged between 20 and 30 years. Ninety-three subjects participated in this study (male: 57, female: 36). The subjects were divided into a one-hour group, a two-hour group, and a three-hour group. All the subjects adjusted the height of their chair to a comfortable position and then seat for one, two, or over three hours. Both prior to and after the experiment, the muscle performance (muscle strength, endurance, and flexibility) of the subjects was measured. Results: In the 2-hours and 3-hour group, muscle strength, flexibility and endurance reduced significantly before and after the study, and the head alignment significantly changed. Conclusion: Thease findings showed that sitting continuously for longer than two hours decreases muscle strength, endurance, and flexibility. A flexed posture affects the muscle performance of the lumbar region and may result in problematic postures, such as a forward head position.

• Journal of the Ergonomics Society of Korea
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• v.34 no.2
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• pp.167-177
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• 2015

Objective: The objective of this research is to develop evaluation checklist for personal office furniture and apparatus to shape comfortable and efficient worksite for workers' welfare improvement, productivity enhancement and labor force preservation, and to identify office work environment by applying the checklist. Background: Because most office workers work using computers in a sitting posture, the ratio of office workers among total musculoskeletal disorders patients is forecast to increase. In this regard, an effort to prevent and manage such musculoskeletal disorders is required. Method: This research developed evaluation checklist for personal office furniture and apparatus by examining 25 domestic and international ergonomic literature and anthropometric data. This research carried out a fact-finding survey targeting the A Office and B Office of one public agency using the checklist. Results: Although, the checklist items on desks, chairs, computers and other goods conformed to the checklist standards, the following items did not conformed: desk height adjustment, seat board depth adjustment, lumbar support depth, foot rest, wrist rest, mouse tray, headset, speaker phone and Bluetooth. Conclusion: The evaluation checklist for personal office furniture and apparatus and fact-finding survey results are considered to be used as basic data for office work environment and workers' welfare improvement. Application: The information drawn from this research can be helpful to manufacturers' design and manufacture of ergonomic furniture and apparatus.