• Journal of the Korean Society for Nondestructive Testing
• /
• v.34 no.5
• /
• pp.390-396
• /
• 2014

A study on smart seats for railroad vehicles was conducted using piezoelectric (PZT) sensors. For this purpose, the concept of passenger friendly smart seats was defined, and a PZT sensor was selected as the optimum sensor based on this concept. Using PZT sensors, simulation tests were performed using a sub-scale model railroad vehicle. In these tests, the main functions of the smart seats were extracted and simplified to improve the effectiveness of the simulation tests. Based on the test results, the system for smart seats proposed in this paper was successfully verified using PZT sensors and the dedicated operation software for the system. This paper will contribute to the improvement of services in high-speed rail systems through advances in ticket checking tasks.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.11
• /
• pp.3525-3537
• /
• 1996

This paper presents a CAD program develpoed on a microcomputer in order to support graphic and computational assessment of ergonomic problems associated with the design of a man-in-cab system. The program is coded to help workspace designers with ergonomic evaluations needed in the design stage. This paper proposed a biomechanical -ergonomic evaluations needed using man and workplace models. The human model is developed to have dimensions obtained from the Korean anthropometric data reported in 1992. Its graphical representation is based on a wire-frame model but, whenever necessary, body segments can be represented by a solid model with hidden line/faces removed and shaded. Workplace models are presented for cabs of the excavator, one of the most popular construction vehicles. A workplace model consists of an operator seat, a steering wheel. two control levers, two pedals, and a control panel. The workplace elements can be modified in their sizes, positions, and orientations by changing the reference point and design parameters. An algorithm for the view test is suggested and loaded to provide a visual evaluaiton of the overall layout of a workplace model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2008.04a
• /
• pp.472-475
• /
• 2008

Generally, a linear vibration theory regards a vibratory system as the superposition of many degrees of vibratory system. Modal analysis stems, in fact, considers the vibration system as what has input, output, and transfer function that relates the input and output. When we want to control, however, the vibratory system, we define, first, the object function that can be vibration energy of certain vibratory system. Then, we try to find the transfer function that can minimize the object function. We can readily extend this approach to control the distributed vibration system. For example, the vibrations of a vehicle, including ships and trains. In this case, we may want to minimize the vibration of the area we select. For example, minimize the vibration of the passengers' seat, but allowing the vibration of other area; for example engines and wheels. This paper introduces a general theory that can control the vibration of the selected area, which can be called as "regional control of vibration." In fact, this is the extended theory of well known sound control of "bright zone"(Choi and Kim, 2002).]. Several illustrative examples demonstrate the applicability and properties that are not available if we use modal analysis method.

• Advances in Automotive Engineering
• /
• v.1 no.1
• /
• pp.61-77
• /
• 2018

In this study, the effects of sitting position of the driver on the whiplash neck injury have been analyzed experimentally by using hybrid III series 50 percentile male crash test dummy. A testing platform consisting of vehicle ground, driver foot rest, driver seat and a 3-point seatbelt has been prepared. This testing platform and the instrumented crash test dummy are prepared for tests according to the Euro NCAP whiplash testing protocol. The prepared test set-up has been exposed to 3 different acceleration-time loading curves defined in the Euro NCAP whiplash testing protocol by performing sled tests. 9 different sled tests have been performed with the combinations of 3 different seating positions of the crash test dummy and 3 different acceleration-time loading curves. The sensor data obtained from the crash test dummy and high-speed videos taken are analyzed according to the injury assessments criteria defined in the Euro NCAP whiplash testing protocol and the criticality of the whiplash injury is defined. It is seen that the backset distance of the driver head with the headrest and the height difference of the top of the head of the driver with the headrest have a great importance on whiplash injuries.

• Journal of Korean Institute of Industrial Engineers
• /
• v.26 no.3
• /
• pp.257-264
• /
• 2000

This research suggested a method by which the driver space can be designed to best accommodate the driver's anthropometric characteristics. Three-dimensional manikins and a variable seating buck were developed and used for this study. Manikins were designed with 18 links comprising the 95th percentile male and 5th percentile female data. The seating buck was built to create various driving environments using the distance and the height between the H-point(hip pivot) of the seat and the AHP(accelerator heel point), the angle of the back rest, the angle of the steering wheel, the vertical distance of the steering wheel, and the location of the T.G.S.(transmission gear shift) knob. Measurements of each variable were collected with a coordinate measuring machine by positioning the 3-D manikin under various combinations of the design factors of the seating buck, which was constructed based on mid-size domestic passenger cars. The data were then converted to the joint angles of the driver. The combination of the measurements for an optimal driving environment is suggested by applying sets of the joint angles at which the driver feels comfortable.

• Journal of Mechanical Science and Technology
• /
• v.19 no.7
• /
• pp.1469-1477
• /
• 2005

Vibrations related to ride comfort should be considered at the beginning of design stage. In general, ride comfort of human is mainly affected by vibration transmitted from the floor and seat. Also, vibration level is very important regarding with running safety on freight wagon. To ensure ride comfort for passenger coach and vibration level for freight wagon, tests had been repeated by different test procedures with several equipments. With different measuring and evaluations for these results, it took much time to evaluate test results. In this paper, a new evaluation procedure was developed combining several software for ride comfort and vibration level test on railway vehicles. In addition, this developed system is capable of ride comfort test and vibration test by a single integrated system that is capable of immediate reporting the test result. With this developed system, the comfort in a passenger coach and the vibration in a freight car were evaluated. And the simulation results from the proposed system are verified by a field test.

• Tribology and Lubricants
• /
• v.37 no.3
• /
• pp.112-116
• /
• 2021

Appropriate friction model usage is important for impact analysis because the relative motions between parts that are in contact for very short durations can vary greatly depending on the friction model. Vehicle seat components that have significant effects on impact analysis are also considered. This paper presents an experimental investigation of various material contact pairs to obtain the friction parameters of the Benson exponential friction model for impact simulation. The Coulomb friction model has limitations for impact analysis because of singularity at zero velocity. Metal/nonmetal materials are prepared, and friction tests are conducted for various sliding speeds, loads, and lubrication conditions. The obtained data are used in the friction model to implement finite element analysis. The parameters of the friction model are obtained by the curve-fitting method. The experimental results show that the friction coefficient with metal/nonmetal contact pairs is stable regardless of the working conditions. The friction model used in this study can also be applied for finite element analysis of the crash conditions, where the friction changes abruptly at the contact interface; the obtained friction parameters are also expected to be more accurate with more precise tests under different working conditions. These results can help improve the accuracy of the finite element analysis.

• Resources Recycling
• /
• v.23 no.2
• /
• pp.3-16
• /
• 2014

Car exhaust $CO_2$ gas reduction and fuel efficiency of the car lighter for the current era is a big challenge. The developments of high-performance Nd magnets, Li-ion secondary battery and exhaust gas purification performance of PGM catalysts used in the lightweight EV and HEV are activated. Country in order to improve the car lighter and function that use the resources of rare metals are ubiquitous imported from China because of export supply control, as soaring prices have unstable supply and demand. Compared to the emissions from the next-generation automotive recycling, waste scarce resources need to be. This study investigated the recycling technology analysis and development of the information technology, or delivered to the researchers by giving national car industry aims to contribute to the development. Findings, pulmonary high-performance motor vehicle emissions in the exhaust gas purification PGM Catalysts, Li-ion battery and Nd magnets recycling technology, such as pre- and post-processing techniques to classify technology, pre-urban mining technology mechanical separation by screening techniques under development, the study and post-processing technology has, pyro and hydro metallurgical smelting technology is established. Waste Recycling in terms of economic efficiency of mechanical components for the intensive study of screening techniques is needed.

• The Korean Journal of Emergency Medical Services
• /
• v.17 no.3
• /
• pp.9-20
• /
• 2013

Purpose: This research project addressed the need to designing more safe and efficient interior of the future ambulance in Korea. Methods: The study sample contained 760 paramedics in 4 districts. Data was collected by using a revised and complemented questionnaire based on literature review. Results: In relation to the efficacy and safety of work, answers related to storage closet showed to be the highest, and the most difficult part of paramedic work in an ambulance was lurching. CPR is the most frequently used emergency care inside an ambulance, but 66% of the paramedics responded that accurate CPR is not possible during vehicle transfer. Safety belts are not worn for 82.8% of the time, because of discomfort (51.3%). 13.8% of the paramedics responded that stretchers are unstable, 29.5% had an experience of having patients fall off the stretcher inside an ambulance. There were comments on installing equipments to prevent noise, and assist communication. Conclusion: The suggested practical layout contains five main modifications 1. Developing specially designed belt is needed for paramedic safety & efficient work. 2. The seats are molded to be ergonomically friendly. 3. Equipments to secure the body and safety devices for CPR are needed. 4. System improvement for communication between the driver seat and paramedics is needed. 5. The stretchers are molded to be maximize efficiency and minimize injury.

• Clinical and Experimental Pediatrics
• /
• v.61 no.8
• /
• pp.253-257
• /
• 2018

Purpose: Child safety seats (CSS) are critical for the protection of children, in case of motor vehicle accidents. Although the national legislation mandates that all newborns must be placed in an appropriately installed CSS during transportation, people often do not perceive the importance of CSS and do not use it as recommended. The purpose of this survey was to understand the use of CSS for the safe transport of newborns from hospital to home. Methods: We interviewed parents of newborn infants, using a structured questionnaire, at the time of their discharge from Cheil General Hospital & Women's Health Care Center, between May 2014 and July 2014. Results: A total of 403 participants were interviewed. The rate of CSS use was only 14.9%. Overall, 76.4% of the families interviewed were not aware about the recommendations on CSS use for newborns when travelling in a car. The provision of education on using CSS significantly influenced their rate of use. Parents who were educated about mounting the CSS in a car used it more as compared with others (25.7% vs. 12.2%) (P=0.002). Furthermore, if parents had heard about the importance or necessity of CSS, they used it more than others did (19.5% vs. 10.6%, P=0.032). Conclusion: Despite the legal regulation, most parents transport their newborn infants without a CSS while traveling from hospital to their home. The rate of CSS use was influenced by parental education and their knowledge about its necessity. Education programs for parents must be reinforced to increase the CSS use.