• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.528-533
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• 2007

A finned tube type heat transfer module has been proposed for a multi-burner water tube boiler. Fins change their geometry along the streamwise direction to maximize the performance, which makes it difficult to apply conventional bulk analysis. The design program has been improved by updating data for every row of tubes along the flow. A numerical simulation has been also performed to evaluate the effect of inlet conditions and validated with experiment. The heat transfer of the first row has been underpredicted by the conventional Zhukauskas correlation, where the acceleration of the flow due to the blockage is not fully inflected. The fin tip temperature is also underpredicted by Bessel solution, because of the interaction with neighboring fins.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1002-1004
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• 1996

In this paper, presented are the results of observability analysis for the vehicle maneuver during In-Flight Alignment of SDINS. The target system for observability analysis is 10th order one. Three trajectories for IFA are considered. To analyze the observability of the time varying system, correlation coefficient is used and to measure the degree of observability of the given system, simulation is carried out using covariance matrix. The results of simulation show that trajectories which are having continuous changes in attitude and acceleration of system is superior to straight trajectory in correcting navigation errors.

• 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.

• Journal of Mechanical Science and Technology
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• v.19 no.7
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• pp.1424-1431
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• 2005

In this study, head injury by impact force was evaluated by numerical analysis with 3-dimensional finite element (FE) model. Brain deformation by frontal head impact was analyzed to evaluate traumatic brain injury (TBI). The variations of head acceleration and intra-cranial pressure (ICP) during the impact were analyzed. Relative displacement between the skull and the brain due to head impact was investigated from this simulation. In addition, pathological severity was evaluated according to head injury criterion (HIC) from simulation with FE model. The analytic result of brain damage was accorded with that of the cadaver test performed by Nahum et al.(1977) and many medical reports. The main emphasis of this study is that our FE model was valid to simulate the traumatic brain injury by head impact and the variation of the HIC value was evaluated according to various impact conditions using the FE model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.119-131
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• 1997

Ball type automatic balancer is used to reduce the vibration caused by unbalance of rotor. In this study, A analytic modeling of a front loaded washing machine with ball type automatic balancer has been suggested theoretically and ADAMS has been used to analyze the dynamic characteristics of automatic balancer. It is found from simulation and experimental results that the automatic balancer suppress the steady state vibration of the washing machine effectively. The test results match well with the simulation results of ADAMS, thereby the dynamic model of ADAMS can be used as virtual prototype to predict the vibration characteristics which could be changed by the modification of design variable and can reduce the design cycle sharply. To maximize the balancing effect of automatic balancer, the friction between balls and race and the deviation between geometric center and rotation center of drum need to be minimized and the optimum design for the stiffness of flange shaft and the angular acceleration of drum should be achieved.

• Journal of the Earthquake Engineering Society of Korea
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• v.18 no.2
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• pp.73-78
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• 2014

In this paper, the stochastic 1D site response analysis method using Monte Carlo simulation and considering thespatial variation of shear wave velocity profile isproposed. To consider thespatial variation of shear wave velocity profile for 1D site response analysis, the proposed method generates random shear wave velocity profiles representing the target site, and Monte Carlo simulation is used to calculate theprobability distribution of the site response analysis results such as thepeak ground acceleration. Through the field application, The applicability of the proposed method is verified through field application.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.342-349
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• 2012

We study the gap effect on detonating high explosives using the characteristic acoustic impedance theory and numerical simulation. A block of charge embedded with multiple gap inserts is detonated at one end to understand the ensuing flame propagation through multiple gap materials. The present high-order multimaterial simulation provides meaningful validation of complex interface tracking algorithm as it is implemented in the SNU-Hydropack code.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.255-261
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• 1998

The train automatic operation control system is an on-board train control system that is widely adopted in modern rapid transit systems. The control system consists of TCMS(Train Control and Monitoring System), ATC(Automatic Train Control), ATO(Automatic Train Operation) and TWC(Train to wayside communication) in the train and wayside facilities. The functions of the system is to regulate train riding comfort, to service limited speed and smoothness during start, acceleration, constant speed travel, and fixed point parking under the corresponding commands. The paper describes the simulation model of the train automatic operation control of subway system, configuration of simulator hardware and software and operational algorithms.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.06a
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• pp.51-54
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• 2011

Telematics services include automatic location tracking for emergency rescue, which is available for use in case of a car accident due to falling off roadways. This paper presents a simulation study on how far a car will fall before it hits the ground, if dropped off the roadway due to an accident or a natural disaster. The greatest distance the falling car can travel is presented in this paper, on the assumption that air resistance as well as the direction and size of the acceleration due to gravity is negligible.

• Journal of Auto-vehicle Safety Association
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• v.13 no.3
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• pp.6-12
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• 2021

This paper presents a lateral stability control for rear wheel drive (RWD) vehicles using electronic limited slip differentials (eLSD). The proposed eLSD controller is designed to increase the understeer characteristic by transferring torque from the outside to inside wheel. The proposed algorithm is devised to improve the lateral responses at the steady state and transient cornering. In the steady state response, the proposed algorithm can extend the region of linear cornering response and can increase the maximum limit of available lateral acceleration. In the transient response, the proposed controller can reduce the yaw rate overshoot by increasing the understeer characteristic. The proposed algorithm has been investigated via computer simulations. In the simulation results, the performance of the proposed controller is compared with uncontrolled cases. The simulation results show that the proposed algorithm can improve the vehicle lateral stability and handling performance.