• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.147-152
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• 2006

This paper presents the dynamic characteristics of MR impact damper for vehicle collision system. Various types of mechanism have been proposed for reduce transmitted force to vehicle chassis and finally protect occupants from injury. In the case of frontal collision, the bumper make main role of isolation material for collision attenuation. In this study, proposed bumper system composed of MR impact damper and structures. The MR impact damper is to adopted MR fluid which has reversible properties with applied magnetic field. MR fluid operates under flow mode with Bingham flow and bellows is used for generation of fluid flow. Mathematical model of MR impact damper incorporated with MR fluid is established. Field dependent damping force is investigated with time and frequency domain. The MR impact damper is then incorporated with vehicle crash system. The governing equation of motion of vehicle model is formulated considering occupant model. Dynamic characteristics of vehicle collision system investigated with computer simulation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.11 s.242
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• pp.1518-1526
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• 2005

With increasing need of transportation services for people with disabilities and the aged, wheelchairs are used as their assistive devices to participate in daily and recreational activities and as seats of motor vehicle. However, as wheelchairs are primarily designed fer mobility assistive devices, not for vehicle seats, wheelchair users may experience serious injury when they meet car crashes. To date, neither engineering guidance for a wheelchair mounting system on the vehicle floor nor safety assessment analysis by a car crash has been studied for the domestic users. In this paper, in accordance with the ANSVRESNA WC-19, a fixed vehicle mounted wheelchair occupant restraint system (FWORS), wheelchair integrated restraint system (WIRS), and wheelchair integrated x-bend restraint system (WIXRS) subjected to frontal impact (20 g, 48 U) were analyzed using compute. simulations for domestic users. We present surrogate wheelchair occupant safety by head injury criteria (HIC), motion criteria (MC), and combined injury criteria (CIC).

• Journal of the Ergonomics Society of Korea
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• v.33 no.2
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• pp.87-96
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• 2014

Objective: The present study is intended to objectively classify upper- & lower-body sitting strategies and identify the effects of gender and OPL type on the sitting strategies. Background: A sitting strategy which statistically represents comfortable driving posture can be used as a reference posture of a humanoid in virtual design and evaluation of a driver's seat. Although previous research has classified sitting strategies for driving postures in various occupant package layout (OPL) types, the existing classification methods are not objective and the factors affecting sitting strategies have not been identified. Method: Forty drivers' preferred driving postures in three different OPL types (coupe, sedan, and SUV) were measured by a motion capture system. Next, the measured driving postures were classified by K-means cluster method. Results: Sitting strategies of upper-body were classified as erect (33%), slouched (41%), and reclined (26%) postures, and those of lower-body were classified as knee bent (42%), knee extended (32%), and upper-leg lifted (26%) postures. Significant differences at ${\alpha}$ = 0.05 in the upper-body sitting strategy by gender and lower-body sitting strategy by OPL type were found. Application: Both the classified sitting strategies and the identified factors would be of use in ergonomic seat design and evaluation.

• Wind and Structures
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• v.2 no.3
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• pp.201-251
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• 1999

Flexible structures may experience excessive levels of vibration under the action of wind, adversely affecting serviceability and occupant comfort. To ensure the functional performance of a structure, various design modifications are possible, ranging from alternative structural systems to the utilization of passive and active control devices. This paper presents an overview of state-of-the-art measures that reduce the structural response of buildings, including a summary of recent work in aerodynamic tailoring and a discussion of auxiliary damping devices for mitigating the wind-induced motion of structures. In addition, some discussion of the application of such devices to improve structural resistance to seismic events is also presented, concluding with detailed examples of the application of auxiliary damping devices in Australia, Canada, China, Japan, and the United States.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.11
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• pp.1397-1405
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• 2013

The optimal rib pattern design of B-pillar trim considering occupant head protection can be determined by two methods. One is the conventional approximate optimization method that uses the statistical design of experiments (DOE) and response surface method (RSM). Generally, approximated optimum results are obtained through the iterative process by trial-and-error. The quality of results strongly depends on the factors and levels assigned by a designer. The other is a methodology derived from previous work by the authors, called the sequential design of experiments (SDOE), to reduce the trial-and-error procedure and to find an appropriate condition for using artificial neural network (ANN) systematically. An appropriate condition is determined from the iterative process based on the analysis of means. With this new technique and ANN, it is possible to find an optimum design accurately and efficiently.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.1
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• pp.138-144
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• 2004

Occupant protection in the side impact of a vehicle becomes one of the most important issues today. So, to reduce development time and cost, it needs test equipment which conducts an accurate simulation of the side impact crash. This paper describes a new test method for side impact, which utilizes a standard 12inch-HYGE-type sled facility. If a side impact sled test can simulate vehicle intrusion very well, it will contribute to develop full-scale side impact crash performance. The newly developed sled test method enables simulation for dummy motion, injury, door velocity, trim crack, and vehicle structure to be accurate. Ant also this sled test method can be applied to the development of side air-bag.

• International Journal of Automotive Technology
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• v.6 no.2
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• pp.161-169
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• 2005

Neck injuries sustained during low speed rear impact are the most commonly sustained traffic injury. Therefore, the analysis of neck injury mechanisms and methods for mitigating and reducing neck injuries during low speed rear impact are a very important issue in the vehicle safety field. In order to find a method to absorb the shock that is transmitted to the occupant, the response of frontal and rear dummy due to the motion of the struck vehicle and the rotational angular displacements of dummies' necks during rear impact at 12km/h speed were investigated using a Working Model 2D. The results suggest that the shock absorption system should be equipped in the bottom of the seat of the vehicle to reduce shock and mitigate neck injury to the occupants.

• Journal of Auto-vehicle Safety Association
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• v.10 no.4
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• pp.7-12
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• 2018

Injury mechanisms of lower extremity injuries in motor vehicle accidents are focused on fractures, sprains, and contusions. The purpose of this study is to evaluate the analysis of lower extremity injury mechanism in occupant motor vehicle accident by using Hospital Information System (HIS) and reconstruction program, based on the materials related to motor vehicle accidents. Among patients who visited the emergency department of Wonju Severance Christian Hospital due to motor vehicle accidents from August 2012 to February 2014, we collected data on patients with agreement for taking the damaged vehicle's photos. After obtaining the verbal consent from the patient, we asked about the cause of the accident, information on vehicle involved in the accident, and the location of car repair shop. The photos of the damaged vehicle were taken on the basis of front, rear, left side and right side. Damage to the vehicle was presented using the CDC code by analytical study of photo-images of the damaged vehicle, and a trauma score was used for medical examination of the severity of the patient's injury. Among the 1,699 patients due to motor vehicle crashes, 88 (5.2%) received a diagnosis of lower extremity fracture and 141 (8.3%) were the severe who had ISS over 15. Nevertheless during 19 months for research, it was difficult to build up in-depth database about motor vehicle crashes. It has a limitation on collecting data because not only the system for constructing database about motor vehicle crash is not organized but also the process for demanding materials is not available due to prevention of personal information. For accurate analysis of the relationship between occupant injury and vehicle damage in motor vehicle crashes, build-up of an in-depth database through carrying out various policies for motor vehicle crashes is necessary for sure.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.347-362
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• 2022

Current vibration serviceability assessment criteria for wind-induced vibrations in tall buildings are based largely on human 'perception' thresholds which are shown not to be directly translatable to human 'acceptability' of vibrations. There is also a considerable debate about both the metrics and criteria for vibration acceptability, such as frequency of occurrence or peak vs mean vibration, and how these might vary with the nature of the vibration. Furthermore, the design criteria are necessarily simplified for ease of application so cannot account for a range of environmental, situational and human factors that may enhance or diminish the impact of vibrations on serviceability. The dual-site VSimulators facility was created specifically to provide an experimental platform to address gaps in understanding of human response to building vibration. This paper considers how VSimulators can be used to inform general design guidance and support design of specific buildings for habitability, in terms of vibration, which allow engineers and clients to make informed decisions with regard to sustainable design, in terms of energy and financial cost. This paper first provides a brief overview of current vibration serviceability assessment guidelines, and the current understanding and limitations of occupants' acceptability of wind-induced motion in tall buildings. It then describes how the dual-site VSimulators facility at the Universities of Bath and Exeter can be used to assess the effects of motion and environment on human comfort, wellbeing and productivity with examples of how the facility capabilities have been used to provide new, human experience based experimental research approaches.

• Journal of the Korean Solar Energy Society
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• v.37 no.2
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• pp.23-33
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• 2017

Accurate prediction of stochastic behavior of occupants is a well known problem for improving prediction performance of building energy use. Many researchers have been tried various sensors that have information on the status of occupant such as $CO_2$ sensor, infrared motion detector, RFID etc. to predict occupants, while others have been developed some algorithm to find occupancy probability with those sensors or some indirect monitoring data such as energy consumption in spaces. In this research, various sensor data and energy consumption data are utilized for decision tree algorithms (C4.5 & CART) for estimation of sub-hourly occupancy status. Although the experiment is limited by space (private room) and period (cooling season), the prediction result shows good agreement of above 95% accuracy when energy consumption data are used instead of measured $CO_2$ value. This result indicates potential of IoT data for awareness of indoor environmental status.