• 한국소음진동공학회논문집
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• 제17권8호
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• pp.766-770
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• 2007

Fuel sloshing in a vehicle fuel tank generates a reluctant low frequency noise, called slosh noise. To reduce slosh noise, whilst many approaches have used the Computational Fluid Dynamics method to first identify fuel behavior in a fuel tank, this paper applies the Transfer Path Analysis method. It is to find contribution of each transfer path from noise transfer function, vibration transfer function and acceleration. Then the final goal is to attenuate slosh noise by controlling them. To this aim, two types of models are studied. One is the decoupled model in which some of connection points of the fuel tank with the vehicle underbody are separated. The other is the modified model which is created by changing noise transfer function and acceleration from the original model. The analysis and validation test results show that the transfer path analysis can be an approach to enhancing slosh noise.

• 한국철도학회논문집
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• 제8권5호
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• pp.483-489
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• 2005

Railway wheel/rail contact conditions have influences on dynamic behavior of the rolling stock. If there are incompatibility problems between the wheel and rail, damages like wheel wear, wheel spalling, rail wear, etc are occurred. Especially wheel and rail profiles are important factors of vehicle curving performance, so compatibility studies between wheel and rail profiles have to be carried out preferentially. In this study, we have studied the compatibility between wheel and rail profiles of KNR conventional line to analyze the dynamic performances of the rolling-stock. Thus we showed the results relating to wheel/rail geometric contact, vehicle running performances as the change of wheel/rail combination.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 특별세미나 특별세션
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• pp.219-227
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• 2006

Since the Maglew ehicle is run over an elevated guideway, the types of guideways affect the running behavior of the vehicle and guideway. The design of a guideway has a strong effect on the costs of constructing guideways, the optimized design of a guideway satisfying running performance is needed for the commercialization of the Maglew vehicle. With an analysis program for dynamics of Maglew vehicles, the dynamic responses of the UTM01 and guideway are numerically analyzed according to types of guideway.

• 한국군사과학기술학회지
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• 제12권5호
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• pp.676-682
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• 2009

The idler wheel installed at the front side of the newly developed tracked vehicle didn't meet the durability requirement by showing the crack failure near the jointed region at the wheel during the field test. To find the crack developing mechanism we constructed finite element model for the idler wheel representing the behavior of interface between each suspension units, material properties from the material test data and actual loading conditions. This paper shows a result that maximum von Mises stress near the bolt hole on the outer rim is higher than inner idler coressponding to the actual test result and that result was reversed by adopting the reinforcement outside of the outer rim.

• 한국정보처리학회논문지
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• 제7권4호
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• pp.1160-1168
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• 2000

Due to the increase in importance of factory-automation (FA) in the field of production, the importance of he autonomous guided vehicle's (AGV) role has also increased. This paper is about an active and effective controller which can flexibly prepare for changeable circumstances. For this study, research about an behavior-based system evolving by itself is also being considered. In this paper, constructed an active and effective AGV fuzzy controller to be able to carry out self-organization. To construct it, we tuned suboptimally membership function using a genetic algorithm (GA) and improved the control efficiency by self-correction and the generation of control rules.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제2권3호
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• pp.242-247
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• 2002

According to increase of the factory-automation(FA) in the field of production, the importance of the autonomous guided vehicle's(AGV) role has also increased. This paper is about an active and effective controller which can flexibly prepare for changeable circumstances. For this study, research about an behavior-based system evolving by itself is also being considered. In this Paper, we constructed an active and effective AGV fuzzy controller to be able to carry out self-organization. To construct it, we tuned suboptimally membership function using a genetic algorithm(GA) and improved the control efficiency by self-correction and the generation of control rules.

• 로봇학회논문지
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• 제6권2호
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• pp.173-181
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• 2011

Recognition of traffic signs helps an unmanned ground vehicle to decide its behavior correctly, and it can reduce traffic accidents. However, low cost traffic sign recognition using a vision sensor is very difficult because the signs are exposed to various illumination conditions. This paper proposes a new approach to solve this problem using an illuminometer which detects the intensity of illumination. Using the intensity of illumination, the recognizer adjusts the parameters for image processing. Therefore, we can reduce the loss of information such as the shape and color of traffic signs. Experimental results show that the proposed method is able to improve the performance of traffic sign recognition in various weather and lighting conditions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.323-328
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• 2002

The control performance of a vehicle installed with an MR(magnetorheological) fluid-based damper is investigated on the basis of Herschel-Bulkley shear model. Generally, most of MR fluid damper has been analyzed based on a simple Bingham-plastic shear model. However, the Bingham-plastic shear model can not well describe the behavior of the damper on the condition of high velocity and high current field input. Therefore, in this study, the Herschel-Bulkley shear model in which the constant post-yield plastic viscosity in Bingham model is replaced with a power law model dependent on shear rate is used to assess control performance of a vehicle with MR fluid damper suspension system. This study deals with a two-degree-of-freedom suspension using the MR fluid damper for a quarter car model. The response for the bump input to identify the fastness of MR fluid damper embedded skyhook controller and requested magnetic field are investigated.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1524-1530
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• 2008

Generally a road vehicle's wrong entry into level crossing gives rise to hazardous events, the eventual collision with a approaching train depends on the effective operation of safety barriers such a abnormal condition detecting or emergency braking. In this paper, the risk assessment models developed for the level-crossing accidents will be introduced. The definition of hazardous events and the related hazardous factors are identified by the review of the accident history and engineering interpretation of the accident behavior. A probability of the hazardous events will be evaluated by the FTA, which is based on the accident scenario. For the severity estimation, the critical factors which can effect on the consequence will be reviewed during the ETA. Finally, the number of casualty for the public(vehicle drivers) and the train passengers are converted into an equivalent fatality.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.356-357
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• 2018

Fuel-cell powered Railway Vehicle Propulsion Systems (RVPSs) are highly desirable due to environment friendly characteristics, and high efficiency of fuel cell (FC). Among various types, the faster start-up and optimality to frequent starts and stops of Polymer electrolyte membrane fuel cell (PEMFC) makes it well suited for propulsion systems. A comprehensive model of PEMFC with reflection of multi-physics behavior required to identify and validate its performance in real RVPSs. Thus this paper will model and simulate the PEMFC unit cell model: a detailed reflection of governing laws and account of dynamic conditions.