• Journal of Applied Reliability
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• v.5 no.1
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• pp.149-165
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• 2005

Air spring system was accepted for railway vehicle secondary suspension to reduce and absorb the vibration and noise. The low natural frequency ensures a comfortable ride and an invariably good stiffness. In this paper, the characteristics and durability test was conducted in laboratory by using servo-hydraulic fatigue testing system to reliability evaluation of air spring for electric railway vehicle. The experimental results show that the characteristics and durability of domestic development productions are obtained the good results. And to guarantee the adaption of air spring, the ride comfort and air pressure variation were measured in train test on subway line.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.4
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• pp.37-43
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• 1997

Damages and public complaints are increased due to construction noise and vibration from several sources. It is urgently needed to develop the easy and practical method to estimate the vibration effect. In this study, to predict the vibration effect, the method using the response spectrum with amplification factor concepts prroposed by Newmark and Hall is used. Also the applicability of the method is examined. Vibration measurement on subway structure, foundation and building structures are performed and the results show that the provided method is practical and can be used to predict the vibration effect.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.6
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• pp.99-103
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• 2014

A hypoid gear is a type of spiral bevel gear whose axis does not intersect with the axis of the meshing gear. The size of a hypoid gear is compact and the ratio of contact is high; therefore, the noise is lower than in other types. Due to these characteristics, the hypoid gear is commonly used in manufacturing processes such as those of escalators and subway screen doors. The purpose of this paper is to develop a reducer using the hypoid gear. In order to check the stability of the proposed reducer, 3D modeling is carried out by CATIA, and a structural analysis is performed using FEM (a finite element method).

• Journal of Environmental Impact Assessment
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• v.21 no.2
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• pp.297-314
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• 2012

This study investigates the stigma effect of unwelcomed facilities on apartment prices through multiple regressions based on hedonic price method. The areas studied are Sang-gye Jugong 7, 9, 10 apartment complexes. The facilities analyzed are the Chang-dong Electric Subway Depot and the Do-bong Driver's License Agency. The factors studied include the environmental variable (the elapsed time since the announcement of the re-location of these facilities), the view commanding, the distance from Chang-dong Depot, the distance from Do-bong Driver's License Test Course, the distance from neighboring facilities (subway stations, schools, parks and so on), the floor and each dwelling's exclusive space. The data used are 2,822 sales which have been collected since January 1, 2006. The facts found are as follows; first, the view commanding and the distance from the unwelcomed facilities are statistically significant. second, the environmental variable, 'days' turns out to have a positive (+) and a negative (-) significant relationship with the dependent variable, 'price', in period II and period IV respectively. This implies that the stigma effect is real. third, there are significant differences in the influence on the apartment prices among the independent variables according to time. fourth, the stigma effect is estimated as 33,686,920 Korean won in the case of the apartments which have the view commanding and 30,311,844 won in the other case before the global economic crisis. This effect seems to decrease to 22,085,078 won after the crisis. These facts suggest that stigma effects could be considered as one of the benefits in the cost-benefit analysis of Chang-dong Depot re-location project to produce somewhat higher NPV or B/C ratio.

• Journal of Digital Contents Society
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• v.12 no.3
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• pp.279-289
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• 2011

The latest hardware and software techniques are combined to give safe walking guidance and convenient service of realtime walking assistance system for visually impaired person. This system consists of obstacle detection and perception, place recognition, and sign recognition for pedestrian can safely walking to arrive at their destination. In this paper, we exploit the sign object detection system in subway station for sign recognition that one of the important factors of walking assistance system. This paper suggest the adaptive feature map that can be robustly extract the sign object region from complexed environment with light and noise. And recognize a sign using fast zernike moment features which is invariant under translation, rotation and scale of object during walking. We considered three types of signs as arrow, restroom, and exit number and perform the training and recognizing steps through adaboost classifier. The experimental results prove that our method can be suitable and stable for real-time system through yields on the average 87.16% stable detection rate and 20 frame/sec of operation time for three types of signs in 5000 images of sign database.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.4
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• pp.47-53
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• 2011

The Electric Multiple Unit (EMU) has many types of door system such as sliding door, plug door etc.al. according to customer's requirements. The sliding door is widely used in Korea but has weak point in the noise problem. In the low operation speed, the noise coming from outer side of the EMU is not an important factor. As the speed is higher than before, noise is increased and make a problem. The main cause of noise is the imperfect air tightness in the EMU. The plug door system has advantages for the noise reduction characteristic in the high speed area. We have been developing electric plug-in door. The door is controlled by Door Control Unit(DCU) following the order of Automatic Train Protection (ATP) that is a kind of train signalling system. DCU has to simultaneously open and close the doors and the operation of it is related to the passengers safety. So DCU is a safety device that is important to reliability and safety. DCU is composed of several devices of control, motor driving, Input/Output, communication and power. In this paper, we will describe the functions, characteristic, requirement, subsystem and test results of DCU used for the electric plug-in door.

• Smart Media Journal
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• v.10 no.4
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• pp.35-44
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• 2021

Recently, the new subway project called "Great Train Express" is in progress. During the tunnel excavation in the center of city, vibration and noise are generated, which make an uncomfortable effect on nearby residents. In order to prepare for this situation, the construction company generally establishes a noise and vibration management plan at the site from the construction planning stage through consultation with the residents of nearby areas and establishment of countermeasures for complaints raised. However, despite the establishment of a noise and vibration management plan, civil complaints have not been fundamentally resolved due to occurring noise and vibration during the construction in progress. In order to solve this problems, one of the best solution is to provide noise and vibration simulation technology with a high sense of reality and immersion for residents of nearby areas. Considering the ease and convenience of using the system, we intend to develop a UI(User Interface) necessary for the development of a simulation system that can directly experience the air blast and vibration based on virtual reality. The results of this study are expected to contribute to the development of virtual reality-based air blast and vibration simulations in the future.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.485-490
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• 2004

Recently, distribution transfer velocity was extremely lowered by high supply rate of vehicle and low road rate. Therefore expansions of transfer network these were subway, road and railway to recover competitive power as a reform measure of physical distribution traffic were become preference previous subject. For reason of that, an expansion of transfer network is meeting competitive power as selected an elevated road in the ground road network that condition of location calm and get out of the existing urban than the underground road to connect oversensitive a large city and expanded small and medium satellite town. In the meantime, while elevated structures construct, they go through the civilian residential section, agriculture land, etc. The consequence is that it raises a vibration, noise, dust, an infringement of the right to a view and an infringement of the right to a sunshine. In this study, we analyzed Quantitatively sunshine quantity with building 3D simulation model of civil structure. Therefore, we present as planning data to reduce a civilian appeal for dispute of the right to sunshine and an economic and time loss between the government and construction company In addition to that, for the standard of the standard plan of usable sunshine quantity program in the practical business, the building of convenient user interface will be the project to be done.

• Explosives and Blasting
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• v.13 no.4
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• pp.5-27
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• 1995

Korea-America tungsten treaty is not only Earnning Us Dollar but also it was turnning point of tunnelling technology development such as a burn cut. Because 10th of specialist worked at Sangdong mine under treaty. The first of all, Experimental blasting pattern for single free face carried out. As a result it has brought the burden and $charge/m^3$ and also space distance. After the center holes are blasted. Remain of the works was the implementation of bench cut against the openning to make the full sectional are required. $Ca=\frac{A}{SW}$ where as A =ndi=m activated area S = Peripheral length of Charged room Ca = Rock Coefficient di=Holes diameter Later in 1980, The Oynaite Explosive is Replaced into Emulsion & Milli-Second Delay Electric Cap. Seqential Blasting machine were Applied in the Site. The Subway Tunnelling have been worked so Carefully for Vibration and Noise to near Shopping and housing area. We carried out Empirical formula to solve city Envoirement pollution as follow For Granite: $V=KW^{0.57}D^{-1.75}$ For Granite : $V=KW^{0.5}D^{-1.5}$ V=PPV(cm/sec) K=Coefficency D=Distance(m) W=Amount of power/delay(kg)

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.395-400
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• 2007

LRT(Light Railway Train), which is a intermediate system of train and bus, is arose for the solution of subway construction cost and the transportation capacity of bus. LRT was introduced in 1980's. About 30 local governments are plan to introduce LRT or constructing LRT, at present. AGT(Automated Guide-way Transit) system, which is a kind of LRT, is operated without driver. Rubber wheeled AGT system can reduce the noise and vibration compare to steel wheeled AGT, so it is estimated as ideal transportation system for urban area. And live loads at bridge are classified as the static load of vehicle and the dynamic wheel contact load which is occurred from the interaction of bridge and vehicle vibration, and the surface roughness. In the case of AGT system, the dynamic increment factor of bridge is greater than the normal train bridge and roadway bridge, because, the weight of AGT vehicle is more light that the train of truck. The exact method for dynamic increment factor is experiment. But this method is needed much money and time, moreover, this method cannot be adopted in design. Therefore, a simulation program for the interaction of AGT bridge, vehicle and surface roughness was developed, in this study. And the program was verified by experiment. As a result, the accuracy of the simulation program can be verified.