• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.4
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• pp.72-81
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• 2012

This study investigates structural, fatigue and modal analyses at bicycle suspension seat post. When weight is applied to the saddle, models 1 and 2 have the weakest strength at the part connected with saddle. And model 2 is greater total deformation and equivalent stress than model 1. Among the cases of nonuniform fatigue loads at models 1 and 2, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of 0 to $-10^4MPa$ and the amplitude stress of 0 to $10^4MPa$, the possibility of maximum damage becomes 4%. This stress state can be shown with 5 to 7times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. Model 1 has better impulse relaxation and passenger sensitivity than model 2. The structural result of this study can be effectively utilized with the design of bicycle suspension seat post by investigating prevention and durability against its damage.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.205-212
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• 2003

This paper may provide a basic design data for the safer car seat mechanism and the quality of the material used by finding out the passenger's dynamic behavior when protected by seat belt during collision. A computer simulation with finite element method is used to accomplish this objective. At first, a detailed geometric model of the seat is constructed using CAD program. The formation of a finite element from a geometric data of the seat is carried out using Hyper-Mesh that is the commercial software for mesh generation and post processing. In addition to seat modeling, the finite element model of seat belt and dummy is formed using the same software. Rear impact analysis is accomplished using Pam-Crash with crash pulse. The part of the recliner and right frame is under big stress in rear crash analysis because the acceleration force is exerted on the back of the seat by dummy. The stress condition of the part of the bracket is checked as well because it is considered as an important variable on the seat design. Front impact model which including dummy and seal belt is analyzed. A Part of anchor buckle of seat frame has high stress distribution because of retraction force due to forward motion of dummy at the moment of collision. On the basis of the analysis result, remodeling and reanalysis works had been repeatedly done until a satisfactory result is obtained.

• The Journal of Korean Physical Therapy
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• v.27 no.2
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• pp.106-111
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• 2015

Purpose: Impaired reaching movement is commonly observed in children with cerebral palsy. The purpose of this study was to determine whether the inclination of seat surface can influence the reaching movement in children with spastic diplegic cerebral palsy (CP). Methods: The subjects were 31 children, 16 children with spastic bilateral CP and 15 typically developing (TD) children. The children performed static sitting and forward reaching under three conditions: a horizontal seat surface (Horizontal $0^{\circ}$), a seat surface inclined anterior 15 degrees (Ant $15^{\circ}$), and a seat surface inclined posterior 15 degrees (Post $15^{\circ}$). A 3-axis accelerometer ('ZSTAR3') was used for analysis of the reaching movement. A 3-axis accelerometer was attached on the manubrium of the sternum, lateral epicondyle of the humerus, and styloid process of the ulna. We measured the reaction time, movement time, and data amount during reaching the 8 cm target with an index finger on the three inclined seat surfaces. Results: Reaction time and movement time for CPs showed significant delay; comparing the TD's and CP's amount was significantly greater than the TD's during reaching task (p<0.05). In particular, CP's reaction time and movement time on a seat surface inclined Ant $15^{\circ}$ was significantly more delayed compared with the other seat surfaces (p<0.05). Conclusion: Our results suggest that seat-inclination intervention may provide an ergonomic approach for children with spastic cerebral palsy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1559-1564
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• 2011

This study presents the development of a machine vision inspection system(MVIS) purposely for car seat frames as an alternative for human inspection. The proposed MVIS is designed to meet the demands, features and specifications of car seat frame manufacturing companies in striving for increased throughput of better quality. This computer-based MVIS is designed to perform quality measures by detecting holes, nuts and welding spots on every car seat frame in real time. In this study, the NI Vision Builder software for Automatic Inspection was used as a solution in configuring the aimed quality measurements. The techniques for visual inspection are optimized through qualitative analysis and simulation of human tolerance on inspecting car seat frames. Furthermore, this study exemplifies the incorporation of the optimized vision inspection environment to the pre-inspection and post-inspection subsystems. The system built on this proposed MVIS for car seat frames has successfully found the possible detections.

• Journal of Sensor Science and Technology
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• v.27 no.4
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• pp.242-248
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• 2018

Bicycle fittings have been used to ride bicycles comfortably while minimizing non-traumatic injuries. To analyze the cause of non-traumatic injuries, it is necessary to measure the body weight distribution in various biking positions. In this study, a weight distribution measurement system was implemented by installing five weighable devices on the saddle, both pedals, and both handle grips of a bicycle. To measure the body weight applied through the saddle, the structure of a commercial seat post was modified and a load cell was installed inside. Weighable pedals and handle grips were designed using a 3D modeling program and fabricated by employing a 3D printer. The body weight distribution for ten bicycle riders was measured when the two pedals were aligned horizontally and vertically. Experimental results showed that the body weight distribution varied significantly depending on human body shape, even after the bicycle fitting was completed. The difference between the body weight measured by the proposed system and a commercial scale was less than 3 %.

• Korean Journal of Health Education and Promotion
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• v.20 no.4
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• pp.79-93
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• 2003

Childhood injuries are the primary cause of death and disability among children aged 5 to 14. Consistent practice of learned safety behaviors can reduce the occurrence of severe injuries among children. However, safety behavior concern is low among Korean-American children specifically and American children, in general. The objective of the study is to evaluate the impact of an unintentional injury prevention curriculum, Risk Watch among Korean-American children. A quasi-experimental design with a nonequivalent control group was used for the designed of the study. Two intervention and two control Korean schools in Atlanta participated in this study. The intervention consisted of weekly lessons in traffic, bicycle, pedestrian, and fire safety. One hundred and two students completed a pre-test and a post-test. The main outcomes were safety behaviors (seat belt use or helmet use), behavioral intentions, and safety knowledge. Analysis of covariance was used for the statistical analyses. Strong intervention effects were found for increasing knowledge of all safety topics in the intervention group. Additionally, statistically significant intervention effects were detected for increasing seat belt and helmet use, as well as behavioral intentions of wearing a seat belt and wearing a helmet, among pre-kindergarten and kindergarten students. For students in grades 1 and 2, intervention effects were found for increasing helmet use. Among students in grades 3 to 8, the intervention group showed statistically significant increases for seat belt use. Limitations of the study and recommendations for modifying and supporting unintentional injury prevention programs for school children are discussed.

• Corrosion Science and Technology
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• v.9 no.6
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• pp.310-316
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• 2010

Recently a fuel oil of the diesel engine of the marine ship is being changed with heavy oil of low quality as the oil price is higher more and more. Therefore the wear and corrosion in all parts of the engine such as cylinder liner, piston crown, spindle and seat ring of exhaust valves are predominantly increased. In particular the degree of wear and corrosion of piston crown is more seriously compared to the other parts of the engine due to operating in severe environment such as the high temperature of exhaust gas and repeating impact. Thus the repair weldment of the piston crown is a unique method to prolong the its life in a economical point of view. In this case, filler metals having a high corrosion and wear resistance such as stellite 6, Inconel 625 and Inconel 718 are mainly being used for repair welding. However it has been often happened that piston crown on the ship,s job site is being actually inevitably welded with mild filler metals. Therefore in this study, filler metals such as E4301, E4313 and E4316 were welded at SS401 steel as the base metal, and corrosion property of their weld metals in the case of post weld heat treatment or not was investigated with some electrochemical methods such as measurement of corrosion potential, cathodic and anodic polarization curves, cyclic voltammogram and polarization resistance etc. in 0.1% $H_2SO_4$ solution. Corrosion resistance of the weld metal of E4301 was better than the other weld metals in the case of no heat treatment, however, its resistance was considerably decreased with post weld heat treatment(annealing:$625^{\circ}C$, 2 hr) compared to other weld metals. The weld metals of E4313 and E4316 showed a relatively good corrosion resistance by post weld heat treatment.

• Journal of architectural history
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• v.28 no.5
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• pp.27-41
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• 2019

This study covered the features and development process of the stylobate of the Sumijwa style, which emerged in Silla around the late 7th century. In the Period of North and South Dynasties, Sumijwa was used as the seat of the Buddha. It was used as a stylobate of tower in the Sui Dynasty and as a stylobate of central buildings in the Tang Dynasty, raising the status of buildings. In the late 7th century, Silla faithfully embodied Buddhist view of the world under its architecture by accepting the latest stylobate of the Sumijwa style. The pagoda of Hwangnyongsa Temple is believed to be the beginning of the stylobate of the Sumijwa style, in Silla. Gradually, in the central buildings within the capital, the stylobate of the Sumijwa style became common. Starting with Bulguksa Temple's Daeungjeon Hall, the materials of stylobate and staircaes will be integrated from the late 8th century. Silla's stylobate of the Sumijwa style can be evaluated as a step-by-step leap in religious, political, technical and aesthetic's terms.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.948-951
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• 2008

Ubiquitous sensor network (USN) based on ZigBee communication protocol has been used in various application fields, such as home-network, intelligent building and machine, logistics, environmental monitoring, military field, security field and etc. The ZigBee is targeted at radio-frequency application that require a low data rate, long battery life and secure network. Especially, the USN system can be applied efficiently to building-indoor where the complex geometry is adopted. In this study, all 90 points of railway cabin indoor were monitored for temperature and humidity using USN technology. All sensors were pre/post-calibrated and the temperature/humidity change were analyzed in a railway cabin in real-time. The results would be useful to develop the cabin heating, ventilating and air conditing (HVAC) system to meet all passengers' thermal comfort regardless of their seat position.

• Korean Journal of Child Studies
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• v.8 no.2
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• pp.61-71
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• 1987

The effects of token and social reinforcement on inappropriate study behaviors of nursery school children were investigated. The subjects were three nursery school boys, and the target behaviors were : 1) out-of-seat behaviors, 2) bothering other children, and 3) disruptive behaviors. The ABAB(Reversal) design was used in this experiment. It consisted of four periods : baseline, reinforcement I, reversal, and reinforcement II. During the reinforcement period, social reinforcement as well as token reinforcement was applied. In all three subjects, inappropriate study behaviors decreased during the reinforcement periods (I, II), and increased during the reversal period, showing the effects of token and social reinforcement. The subjects showed stability in three post-experimental tests, indicating that modification of inappropriate study behaviors was being maintained.