• Journal of KSNVE
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• v.9 no.6
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• pp.1145-1151
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• 1999

Sensitivity analysis and structural modification technique are used to reduce the interior noise of a passenger car. The sensitivity analysis for the noise level at the rear seat shows that the stiffness change at the front lower member and the rear roof rail are sensitive. Using the structural modification method, we verified that the reinforcements at those members decrease the noise transfer function from the body to the rear seat. The combined application of the sensitivity analysis and structural modification method can decrease the noise level effectively.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.264-266
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• 1997

Fuel cell systems offer high energy efficiencies for transportation application. In addition, they can use alcohols and alternative fuels as the fuel, while producing little or no noxious emissions. Fuel cell-powered vehicles should be competitive in performance characteristics and in capital and maintenance costs with internal combustion engine vehicles. The objective of the present study is to design a fuel cell-powered passenger car to analyze technical feasibility.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.291-298
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• 1998

The object of this study is to investigate the effect of elastic wheel from the viewpoint of noise and vibration of railway vehicle. The vibration reduction was predicted from the FRF difference between elastic wheel and solid wheel by FEM simulation. The elastic wheel and solid wheel were compared in viewpoint of carbody vibration and car interior noise level. The effect of elastic wheel on the noise and vibration of subway vehicle was obtained. But, the application of elastic wheel must be reviewed in some aspect.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.495-502
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• 2000

For the tunnel design of the first class on new Seoul-Chunchon railway, we investigated for train speeds to run through tunnels without ear-discomfort of passenger in cabin by application of numerical analysis. Also we analyzed the effect of the wind speed induced by train in tunnel that is very harmful to the workers on railroad and the effect of the air-pressure fluctuations which get the fatigue to the tunnel lining and the car body.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.487-494
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• 1999

The object of this study is to reduce the subway noise by the low noise wheel. The vibro-acoustic reduction was predicted from the FRF difference between low noise wheel and solid wheel by experimental modal analysis. The low noise wheel and solid wheel were compared in viewpoint of car interior/exterior noise. The effect of low noise wheel on the noise of subway train of 6 vehicles was obtained. But, the application of low noise wheel must be reviewed in some aspect.

• Science of Emotion and Sensibility
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• v.5 no.4
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• pp.77-84
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• 2002

In this paper, we propose the NAVER, a general framework for multipurpose virtual environments, and introduce the case study of evaluating car prototypes using cave-like systems. As a framework to implement variant applications in virtual environment, NAVER is extensible, reconfigurable and scalable. NAVER consists of several external modules (Render Server, Control Server and Device Server), which communicate each other to share states and user-provided data and to perform their own functions. NAVER supports its own scripting language based on XML which allows a user to define variant interactions between objects in virtual environments as well as describe the scenario of an application. We used NAVER to implement the system for evaluating car prototyes in a CAVE-like virtual environment system. The CAVE-like virtual environment system at KIST consists three side screens and a floor screen (each of them is a square with side of 2.2m), four CRT projectors displays stereoscopic images to the screens, a haptic armmaster, and a 5.1 channel sound system. The system can provide a sense of reality by displaying auditory and tactile senses as well as visual images at the same time. We evaluate car prototypes in a CAVE-like system in which a user can observe, touch and manipulate the virtual installation of car interior.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2672-2678
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• 2011

Carbody of rolling stock has been gradually changed as whole wood, steel frame with wood car body, whole steel car body with rivet and whole monocoque carbody with welding. And also mild steel has been used widely to material of structure, but usage of stainless and aluminium which have lightweight and high corrosion resistance is being increased lately. Structure is being commercialized to AED(All Extrusion Design),whole double skin with hollow excluded shape such as aluminium structure from SSD(Sheet Stringer Design), single skin consists of traditional frame and outside plat. Traditional aluminium carbody had many problems from reduced strength in welding combination section because car body is consist of small extruded material affected heat by welding. On this study, we proposed the plan to improve the body strength and quality with large-scale aluminium extruded material by minimizing welding concentration in combination section.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.760-771
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• 2012

In this paper, a blind spot of motor car, and the put case that is driven the miniature model motor system, when make practical application of the permanent magnet synchronous motors(PMSM) braking and having had the ability that can all absorb regenerative power by means of electric brake which is occurred. a tow system of a miniature model motor traction system is established by 1C1M methods to control individually permanent magnet synchronous motors (PMSM) of each motor. vector control method is applied in order to improve ride quality of motor car and the efficient use of energy. it was obtained excellent experiment results from the simulations as a function of momentum load and miniature model. Also, this study is investigated the regenerative braking power securities of permanent magnet synchronous motors, speed detection to stop electric brake at extremely very low speed and motor control method of algorithm.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.57-65
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• 2011

In this study, estimated the minimum lane width for the curved section by analyzing of lateral sway distance and compared the lane width for result of this study and a precedent study for straight section on urban roads. Then suggested minimum lane width of road alignments and vehicle classes. The lane width of curved section that was investigated was 2.79m~3.40m. Analysis of frequency distribute and cumulative frequency distribution for lateral sway distance on the basis of 85% of the suggested vehicles. The result of study, minimum lane width for the curved section was 2.31m~2.58m in the case of small size car and 2.80m~3.27m in the case of large size car. Result of this study is judged that it is necessary to case for introduction of green transit, during road construction and construct a road for small size car. Expect result of this study can be used for the application of flexible design standard according the purpose of road designer.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.4
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• pp.109-118
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• 2012

Large number of part design for aircraft and automobile is preceded by functional or sectional design groups for efficiency. However, interferences and gaps can be found when the parts and sub-assemblies by those design groups are to be assembled. These interferences and gaps cause design changes and additional repair processes. While interference problem has been resolved by digital mockup and concurrent engineering methodology, gap problem has been covered by temporary treatment of filling gap with sealant. This kind of fast fix causes fatal problem of leakage when the gap is too big for filling or the treatment gets old. With this research, we have developed a program to find the gap automatically among parts of assembly so that users can find them to correct their design before manufacturing stage. By using decomposition model representation method, the developed program can search the gap among complex car body parts to be visualized with volumetric information. It can also define the boundary between the gap and exterior empty space automatically. Though we have proved the efficiency of the developed program by applying to automobile assembly, application of the program is not limited to car body only, but also can be extended to aircraft and ship design of large number of parts.