• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.133-134
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• 2009

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.182-194
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• 1999

Occupant injury in rear end impact is rapidly becoming one of the most aggravating traffic safety problems with high human suffering and societal costs. Although rear end impact occurs at relatively low speed , it may cause permanent disability due to neck injuries resulting from an abrupt moment, shear force , and tension/compression force at the occipital condyles. The analysis is performed for a combined occupant-eat model response, using the SAFE(Safety Analysis for occupant crash Environment) computer program. The computational results are verified by those from sled tests. A parameter study is conducted for many physical and mechanical properties. Seat design has been performed based on the design of experiment process with respect to five parameters; seat-back upholstery stiffness, torsional stiffness of the seat-back. An orthogonal array is selected from the parameter study. A good design has been found from the analysis results based on the orthogonal array. The results show that reductions of stiffness in seat-back upholstery and joint are the most effective for preventing neck injuries.

• Analytical Science and Technology
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• v.29 no.3
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• pp.136-141
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• 2016

In the present study, the distribution of glass particles inside 10 patrol cars of Chungnam Province has been studied. The target seats were front seats (driver’s seat, passenger’s seat) and the back seat. The target areas were the bottom of the seat (seat contacting buttocks, back of the seat, and the corner of the seat (the bottom and back attached part)). The target areas were tape lifted with an adhesive tape. The glass particles adhering to the adhesive tape were examined and counted under a stereomicroscope. The total number of glass particles found was 679. Among them, 471 (driver’s seat 293, passenger seat 178) were collected from front seats, which are usually occupied by police officers. The majority of glass particles were under 0.49 mm size. The results show that the majority of glass particles can be found on the front seats, rather than on the back seat. There is a high probability that glass particles found on the front seat adhere to police officers, so that to get further transferred to the convict upon physical contact (secondary transfer). Thus, there is a risk of misinterpretation of the value of glass evidence in the course of forensic examinations. Hence, a separate method to prevent cross contamination has to be prepared by police authorities as soon as possible.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.4751-4755
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• 2011

This study investigates the plastic suspension assembly which is installed on inside of vehicle seat and support passenger's back to supply the comfortable ride performance. It aims to develop the structural design in order to support driver's back uniformly and assemble seat back frame with plastic suspension effectively. The part of suspension is designed by considering the body pressure distribution of driver and it has the same size as the practical model on simulation analysis. It is confirmed that the analysis result of plastic suspension approaches the practical measured values and the better body pressure distribution can be obtained as compared with the existing wire type.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.476-482
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• 2017

This study examined the effects of the seat height of a chair on the muscle activity of the erector spinae and rectus abdominis. Thirty healthy subjects were asked to sit on chairs at three different seat heights. The muscle activities of both the erector spinae and rectus abdominis were measured by surface electromyography. The data were analyzed by repeated one way ANOVA and the muscle activity was compared according to the seat height. The alpha level was set to 0.05. The results showed that the muscle activities of the erector spinae were not significantly different among the three seat heights. The muscle activities of the rectus abdominis were significantly different among the three seat heights. Both the rectus abdominis muscle activities were significantly greater in the low seat height than the other seat heights. These results showed that the seat height of the chair affects the muscle activities of the rectus abdominis muscle, leading to musculoskeletal pain, such as low back pain. Therefore, the seat height of a chair with a correct sitting position is important for preventing musculoskeletal pain.

• Journal of KSNVE
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• v.10 no.2
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• pp.269-279
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• 2000

This paper deals with the development of biomechanical model on a seat with backrest support in the vertical direction. Four kinds of biomechanical models are discussed to depict human motion. One DOF model mainly describes z-axis motion of hip, two and three DOF models describe z-axis of hip and head, and while nine DOF model suggested in this study represents more motion than the otehr model. Three kinds of experiments were executed to validate these models. The first one was to measure the acceleration of the floor and hip surface in z-axis, the back surface in x-axis, and the head in z-axis under exciter. From this measurement, the transmissiblities of each subject were obtained. The second one was the measurement of the joint position by the device having pointer and the measurement of contact position between the human body and the seat by body pressure distribution. The third one was the measurement of the seat and back cushion by dummy. The biomechanical model parameters were obtained by matching the simulated to the experimental transmissiblities at the hip, back, and head.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.7 no.1
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• pp.87-98
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• 1997

In this study, subway train vibration has been measured to characterize the whole body vibration of Seoul subway lines for various human postures. Results show that the floor vibration level of the subway trains in the vertical direction is higher than that in other directions. At the standing human posture, vibration level of the head in the right-left direction are increased while that in the vertical direction is decreased. It is assumed that the different flexibility of the human body and the rolling motion of the subway trains are the main cause. At the sitting posture with back seat on, vibration level in the right and left direction at the human ischial tuberosities is lower than that in other directions. Results also show that there were little difference between back-seat on model and back-seat off model. Transmissibility analysis shows how the subway vibration affects the response of a human body.

• Journal of the Ergonomics Society of Korea
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• v.15 no.1
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• pp.69-78
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• 1996

Current fighter pilots, flying new generation aircrafts with high performance, are under severe stress during aerial combat maneuvering when they are exposed to high sustained +Gz(Head-to-foot) acceleration stress. Two major factor limiting performance during high sustaied +Gz acceleration stress are loss of vision-greyout or blackout, and loss of consciousness (LOC). These symptoms are believed to occur as a result of insuff- icient blood flow to the retina and the brain. This study was conducted to evaluate the effects of high sustained +Gz stress under different seat back angle. The results. obtained by the biodvanmic computer simulations using the ATB(articulated total body) model, are represented with respect to three variables, such as HIC(head injury criterion) value, average G, and maximum G. The results demonstrate that the seat back angle(over $30^{\circ}C$) had a significant effect to decrease +Gz stress on the head segment and had no significant effect on HIC.

• Journal of Korean Physical Therapy Science
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• v.3 no.4
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• pp.171-179
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• 1996

This study was conducted to investigate on the standardization of wheel chair for Korean in the twenties college students. Study population included 200 students in Andong junior college from September 25, 1996 to October 16, 1996. Basic measurements for wheel chair production were carried out A(from behind calf to rear of buttocks), B(from the popliteal fossa to the bottom of the heel), C(from the bottom of the elbow to the seating surface), D(from the seating surface from to midseapula), E(across the hip at widest point). The results are as follows. There was a statistical significance between male and female body dimension measurements in the A(p=0.0018), B(p=0.0001), E(p=0.0001), the other side not significance of C(p=0.1193), D(p=0.8467). The standard dimension of wheel chair included seat depth 40.6 cm, seat height 48.1 cm, arm height 25.8 cm, back height 35.7 cm, seat width 39.6 cm in the twenties male college students and in female case included seat depth 39.3 cm, seat height 45.2 cm, arm height 26.5 cm, back height 35.8 cm, seat width 41.2 cm.

• Journal of Industrial Technology
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• v.28 no.A
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• pp.71-74
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• 2008

Belt Integrated Seat(BIS) has many advantages compared to the existing seats. Due to the development of materials and manufacturing technology, BIS, which has been used restrictely in the past, has gone through a rapid growth. As a result, its advantages have gained attention and the possibility of replacing the existing seats has grown. The need to develop BIS has risen and presently joint development with associated industries is in progress. For its first goal, the development and research of Recliner sensor has been selected. Recliner sensor is an essential part of the BIS in which the belt is incorporated onto the seat. In seat-belts, there is an inclination sensor which locks the belt according to the angle of a car. Because the inclination sensor can change frequently depending on the back of seat, a device which can enhance the inclination sensor according to the angle of the back of seat. It is the Recliner sensor that play's this role. Studies on Recliner sensor within and outside Korea has not yet made a salient progress, and due to this fact, the joint development has made a start by benchmarking other company's products. Currently, in other to set the course of the development, a research in patents and various other information is being done. In addition, for the purpose of developing a product which will be compatible with the existing products, a prototype will be made and tested before a new product makes its launching on the market.