• Proceedings of the KSR Conference
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• 1998.05a
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• pp.265-272
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• 1998

In this paper, the intoner noise reduction for subway railroad vehicles was studied by improving transmission loss of carbody panels and side doors, and on-line tests were conducted to examine the exterior noise levels at various running conditions. Also the transmission loss for design candidates of the carbody specimen was measured in two reverberation rooms. From the results of the tests, side door gap is the most dominant factor affecting the Interior noise level of subway railroad cars with a sliding typed side door. The next one is revealed to transmission loss of a floor panel. To improve the transmission loss of the carbody, many activities were conducted such as, treatment of resilient and sound-absorbing materials and reducing the gap of the side door by adopting a brush and rubber, etc. The estimated interior noise level for modified car which is designed with improved carbody panels is lower than original car by about 5㏈.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.801-806
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• 2002

The operation of double deck train have increased in many countries such as Japan france, and the Netherlands as efficient, safe and convenient alternative transportation systems. Because of continuous concentration of population into Seoul metropolitan and serious traffic jam, the number of passengers using the commuter train have been increased rapidly. Considering these situations, we can find one of the solutions for heavy traffic problems through double deck trains. Stainless steel, and aluminum extruded panel are used to reduce the weight of double deck train. In this paper we compare the results of structural analysis of the double deck car body structures with Al extruded panels and stainless steel. We hope the results of this study may be used as basic guidelines in designing double deck trains in the future.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.302-307
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• 2010

Development of light-weight high speed train (HST) based on distributed motor control with the top speed of 350 km/hr has engendered a need for abatement of the interior noise of the train cabin. The development of noise abatement measures is crucial at the design stage of the train car since the noise transmission characteristics of the car structure directly influences the cabin interior noise. Since the transmission loss measurement using the entire car structure is often not feasible, especially at the initial stages of the train development, investigation of transmission characteristics using small-scale reverberation chamber can furnish useful alternative source of predicting the noise level. In the present study, white noise is generated at source and transmission loss estimated by performing measurement of a specimen in a scaled reverberation chamber. Comparison of measured values with the previously derived numerical values show good agreement in the overall trend but appreciable quantitative differences still remain.

• IE interfaces
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• v.17 no.4
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• pp.482-489
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• 2004

As the functional characteristics of passenger cars have reached to a satisfactory level, customers place more concerns with the aesthetic aspects of interior designs. The present study developed satisfaction models of passenger car interior materials for six parts including crash pad, steering wheel, transmission gearshift knob, audio panel, metal grain, and wooden grain. Eight to fifteen material design variables such as color, embossing, and smoothness were defined for the six interior parts based on literature survey, customer reviews, and expert opinions. A satisfaction survey was conducted for 30 vehicles with 30 participants ($mean{\pm}SD$ of age = $28.7{\pm}6.6$) by using a modified magnitude estimation scale. Based on the survey results, the material design variables were screened from statistical, technical, and practical aspects. With the screened variables, satisfaction models were developed by using the quantification I method for the six interior parts, indicating the importance of material design variables and preferred material properties.

• Corrosion Science and Technology
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• v.2 no.5
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• pp.247-251
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• 2003

The corrosion forms of automotive body panels are various. One of the representations is a corrosion pitting and its propagation on the lapped portion by galvanic corrosion. But it has been difficult in correlation analysis about the corrosion propagation rate and mechanism of pitting and the actual automotive body in field. This present study interprets experimentally the rust pitting occurrence mechanism on the lapped panels through experimental methods. And field car investigation was executed for correlation analysis with experimental results. This paper compares corrosion propagation rate by pitting on hot-dip galvannealed steel sheets with corrosion forms in the automotive field condition. The research fundamentals which make it possible to predict the pitting occurrence and propagation on the lapped panels in the actual vehicles are given.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.141-148
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• 2002

Repair were made for front pillar, center pillar and side-step panel for lightweight vehicles with head-on and 40% off-set collision of 15 km/h in a RCAR standard. The salt dilution was sprayed and the compression tests were performed for vehicles with and without anti-corrosional treatment after repair. After 764 hours of salt-dilt sprayed test without using anti-corrosion, the mean penetration depth fur corrosion was shown to be 58% of the thickness. The resulyed decrease in bending stiffness by 10∼20% can cause reduction of the residual life and crash-absorption capability for damaged vehicles. The corrosoin safety tests showed that the anti-corrosional treatment should be made to improve the safety characteristics for a or damaged car.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.6
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• pp.786-794
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• 1998

This paper proposes an automatic microshaping technology using laser and applies it to implementation of semicutting control system of the panel inside which a car air bag is equipped. Since it is impossible to project laser directly onto the desired working point of a target panel due to fixedness of laser generator, we reflect the generated laser, using reflection mirrors and focusing lenses, to project onto the desired working point. Also, in order to conduct an uniform semicutting control with constant width and depth, we control the end-effector of manipulator, which grasp the laser reflection mirror, to track working path with constant speed and orientation. The validity and effectiveness of the proposed methods are checked through experiments tracking a path formatted with straight lines and arcs.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.91-97
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• 2003

In many countries such as Japan, France and so on, the number of double-deck trains has been dramatically increased for the purpose of public traffic. Several researchers have performed feasiblilty studies related to the operations of double deck rolling stock vehicles in Korea since 2001. In recent years, rolling stock vehicles are required to have light weight to save energy consumption and maintenance costs. For these reasons, the standard EMU vehicle developed by KRRI and Kwan-Ju EMU(Electric Multi Unit) are made of aluminum extruded panels. The concept model of a double-deck rolling stock vehicle investigated in this study is also designed to use AEP(Aluminum Extruded Panel). In this paper, the methods related to the structural strength improvements of the car body are proposed through careful modifications of thicknesses and shapes of AEP.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.567-571
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• 2002

In this study we reported the Smoke Density test method of interior panel of railroad passenger car and investigated the specific smoke density(Ds) by NBS smoke chamber to the variance of some test conditions. First we compared the result of Ds from ISO 5659-2 with that from ASTM E662 for same phenol FRP Secondary studied the Ds value to the variance of resin type and to the variance of specimen shape.

• Journal of the Korean Regional Science Association
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• v.31 no.3
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• pp.19-37
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• 2015

The purpose of this study is to confirm a structural relationship on factors affecting ratio of public transportation spending to a car-owning household's total transportation expenditure. For this purpose, informations of household's attributes and activities were gathered using the 13th Korean Labor and Income Panel Study (KLIPS), and information of land-use and transportation conditions on their residential locations was collected and processed. A structural equation model (SEM) on determinants affecting ratio of public transportation expenditure was constructed, based on an execution result of factor analysis using the analyzing database. The latent variables were derived as land-use/transportation characteristic, household's attribute and household's activity. In the analyzing result of the SEM, the entire latent variables were significant. And, the first two latent variables had positive influences, and the last latent variable had a negative impact. To promote public transportation use of the car-owning households, this study suggests that the policies such as enhancement of convenience in public transportation use for the household's activities and improvement of the land-use/transport conditions are required.