• Journal of ILASS-Korea
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• v.21 no.3
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• pp.130-136
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• 2016

NOx and PM are important air pollutants as vehicle management policy aspect. Medium-duty truck is the main source of the pollutants although the vehicle market share is only 3.5%. National emission portion of NOx and PM form the mobile sourece are 14% and 16% respectively. In this study it was investigated that characteristics of air pollutants emission on medium duty truck equipped with EGR and SCR system. Vehicle's test reflected driving cycle on the chassis dynamometer, and applied test cycle was WHVC(World Harmonized Vehicle Cycle) mode. The test cycle include three segments, represent urban, rural and motorway driving. Based on the test results NOx, PM, HC were less emitted form SCR vehicle than EGR vehicle. And CO was less emitted form EGR vehicle than SCR vehicle due to CO oxidation reaction on DPF surface. And most air pollutants reduced as average vehicle speed increased. Pollutants were less emitted on motorway section than urban and rural sections. But highly NOx emission on motorway section was verified according to increased EGR ratio on fast vehicle speed. HC and CO additional emission was identified as 68%, 58% respectively during SCR vehicle's cold engine start emission test. NOx additional emission was detected by 24% on SCR vehicle's condition of engine cold start while not detected on vehicle equipped with EGR. SCR vehicle's additional NOx emission was derived from low reaction temperature during engine cold start condition. medium-duty truck emission characteristics were investigated in this study and expected to used to improve air pollutants management policy of medium-duty truck equipped with SCR & EGR.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.115.1-115
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• 2002

This study proposes a new conceptual Hybrid Electric Brake System (HEBS) which overcomes the problems of the conventional hydraulic brake system. The HEBS uses the contactless brake system when vehicle speed is high to obtain superior braking force by eddy current, which is induced in pole area by magnetic flux through a rotating conductive disk. On the contrary, when a vehicle speed is low, contact type brake system such as conventional hydraulic brake system makes higher braking force. HEBS transfers faster a braking intention of drivers and guarantees a safety of drivers because of vehicle dynamic superior controllability. Braking torque analysis is peformed based upon Lee. Barn\ulcornermath...

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.51-56
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• 2013

With the active development of hybrid electric vehicle (HEV), the application of interior permanent magnet synchronous motor (IPMSM) has been expanded. As wide driving region of IPMSM for electric vehicle (EV) traction motor is required, many studies are conducted to improve characteristics of a motor in both low and high-speed driving regions. A motor in high-speed driving region generates (produces) large stress to the rotor. Thus, the rotor needs to be designed considering the mechanical safety. Therefore, in this paper, we conducted stress analysis and electromagnetic analysis to determine the centerpost's distance which is considered important during the design of IPMSM for EV traction motor in order to secure mechanical safety and satisfy specifications of output requirement.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.942-948
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• 2011

The performance of a supercharger for vehicle using solar cell attached on the exterior of a car, an auxiliary battery, and an air compressor was evaluated in this study. This supercharger is composed of a solar cell of 40W, a battery of 60 Ah, an air compressor of 17 A, 8 $kgf/cm^2$ and an air tank of 8L. It takes about 6 days to charge the battery with the solar cell and the high pressure air of 8L can be supplied about 70 times to engine intake with this battery. The intake pressure increased by about 20~40% with this supercharger. The vehicle power and accelerating performance are enhanced by 87% and 50% each in the low speed range. But the performance improved little in the high speed range because of the rather constant flow rate of air supplied by this type of supercharger.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2473-2481
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• 2013

The two characteristics of two-lane-and-two-way traffic flow are platoon and overtaking triggered by low-speed vehicle. It is crucial to develop a robust model which simultaneously generates the behaviors of platoon by low-speed vehicle and overtaking using opposite lane. Hence, a microscopic two-lane and two-way vehicle model was introduced (B. Yoon, 2011), which is based on CA (Cellular Automata) which is one of discrete time-space models, in Korea. While the model very reasonably explains the behaviour of overtaking low-speed vehicle in stable traffic flow below critical density, it has shortcomings to the overtaking process in unstable traffic flow above the critical density. Therefore, the objective of this study is to develope a vehicle model to more realistically explain overtaking process in unstable traffic flow state based on the model developed in the previous study. The experimental results revealed that the car-following model robustly generates the various macroscopic relationships of traffic flow generating stop-and-go traffic flow and the overtaking model reasonably explains the behaviors of overtaking under the conditions of both opposite traffic flow and stochastic parameter to consider overtaking in unstable traffic flow state. The vehicle model presented in this study can be expected to be utilized for the analysis of two-lane-and-two-way traffic flows more realistically than before.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.9
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• pp.950-956
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• 2014

In this paper, the real-time detection method of a DDP (Driving Direction Point) is proposed for an unmanned vehicle to safely follow the center of the road. Since the DDP is defined as a center point between two lanes, the lane is first detected using a web camera. For robust detection of the lane, the binary thresholding and the labeling methods are applied to the color camera image as image preprocessing. From the preprocessed image, the lane is detected, taking the intrinsic characteristics of the lane such as width into consideration. If both lanes are detected, the DDP can be directly obtained from the preprocessed image. However, if one lane is detected, the DDP is obtained from the inverse perspective image to guarantee reliability. To verify the proposed method, several experiments to detect the DDPs are carried out using a 4 wheeled vehicle ERP-42 with a web camera.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1607-1613
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• 2008

The present investigate is a base investigate required in development of DMT wagon train. And it deduced that follows by developing trail analysis model about Modalohr wagon train and examining traveling movement specific using analysis model developed. Vibration acceleration of all direction was increased with addition of travel speed and first suspension. But in case of right and left vibration acceleration, that could influenced by nonlinear specific of first suspension. Therefore checking about those is needed. Frequency of $2{\sim}3\;Hz$ and $7{\sim}8\;Hz$ generated in Right and left, up, down vibration of vehicle. And right and left vibration of bogie generated $25{\sim}35\;Hz$ in low speed section and frequency of $40{\sim}50\;Hz$ in high speed section, $25{\sim}35\;Hz$ in low speed section, $10{\sim}15$ or $40{\sim}50\;Hz$ in high speed section.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.3
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• pp.197-204
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• 2005

A waterjet propulsion system has many advantages compared with a conventional screw propeller especially for amphibious armored wheeled vehicles because of a good maneuverability at low speed, good operation ability at shallow water, high thrust at low speed to aid maneuverability and exit from water, etc. The POD type waterjet is adequate for the present wheeled vehicle because the weight is lighter and L/B is longer than the conventional armored amphibious vehicle. Resistance and self-propulsion tests with a 1/3.5-scale model are conducted at PNU towing tank. Based on these measurements, the performance is analyzed according to ITTC 96 standard analysis method and also according to the conventional propulsive factor analysis method. Based on these two methods, the full-scale effective and delivered powers of amphibious armored wheeled vehicle are estimated. This paper emphasizes the analysis method of model test of the waterjet propulsion system for a amphibious armored wheeled vehicle and the model test technique together with the comparison of the two analysis methods.

• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.243-250
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• 2007

In general the Maglev vehicle is run over the elevated track called guideway. Since the guideway is elevated, the flexibility of the guideway has an effect on the dynamic responses of a vehicle such as its stability and ride quality. To improve the running performance of the Maglev vehicle and design a cost effective guideway using the dynamic analysis, the dynamic analysis of the system requires the coupling model of the Maglev vehicle and guideway. A coupling model based on multibody dynamics is proposed and programmed. With the program, the UTM01, a low speed Maglev vehicle, is analyzed and discussed.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.3
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• pp.238-245
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• 2001

This paper describes a method for detecting a close leading vehicle using the contour of the vehi-cles rear wheels. The contour of a leading vehicles rear wheels in 속 front road image from a B/W CCD camera mounted on the central front bumper of the vehicle, has vertical components and can be discerned clearly in contrast to the road surface. After extracting positive edges and negative edges using the Sobel op-erator in the raw image, every point that can be recognized as a feature of the contour of the leading vehicle wheel is determined. This process can detect the presence of a close leading vehicle, and it is also possible to calculate the distance to the leading vehicle and the lateral deviation angle. This method might be useful for developing and LSA (Low Speed Automation) system that can relieve drivers stress in the stop-and-go traffic conditions encoun-tered on urban roads.