• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1292-1294
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• 2002

In this study, the block section length of the given area has been analyzed to improve the headway which caused by the mixed operation of high speed trains and normal trains on the electrified railway of Dongdaegu to Busan. After establishing the average length of block section and the adjustable average length of block section of Dongdaegu to Busan, it is possible to perform the headway simulation regarding the signal system based on the established length. Although high speed trains as well as low speed trains including freight trains operate together, the experimental results indicate that the modification of the block section length shows the possibility of the improvement of headway.

• Proceedings of the KSR Conference
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• 2006.05b
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• pp.917-917
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• 2006

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.492-494
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• 1999

To improve safety operation of urban transit, compatible design of signaling system is most important factor at future train operation and management. Therefore, signaling system should be designed compatible transport demand of target year. In addition, signaling system should be designed improved train safety, based fail-safe principle. Most of all, to solve passenger concentration, high density and to improve efficiency of train operation. Headway improvement of train is most important. Train organization length of new urban transit as light rail is generally shorter than EMU. Therefore, to increase passenger service and operation efficiency, minimum headway of one minute in this system should be important required.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.1
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• pp.1-10
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• 1989

The stress history of a bridge is different depending on the characteristic of traffic flow. Because the flow is varied with vehicle type, weight and headway time etc., statistical analysis in bridges is necessary to estimate the history by traffic flow. By applying the statistical analyses in fracture mechanics, the remaining service life of the structure can be estimated. In this paper, 1)the statistical analysis of vehicle type, weight and headway time etc. to analysis randomness of traffic flow, 2)measuring and analysis of stress history of a real bridge, 3)reappearance of stress history by Monte-Carlo Simulation using constitution ratio of vehicle type, weight and headway time as probabilitic variable, 4)comparision of the calculated and modelled stress history, 5)calculation of reduction factor, 6)comparision of frequency of stress range depending on span length etc. were performed. From the results, the basic modelled stress history which is necessary for the method of estimation of the remaining service life of the structure could be suggested.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.451-454
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• 1995

Increasing the transfortation efficiency is very important issue in railway system. Speed-up of train and shortage of headway can be its solution. Headway can vary with blocksection length, characteristics of the railway and signalling systems. Safety braking distance needed for passenger's safety is very important factor in block section division method. In this study, basic block section division program was developed with the differential ratio of braking distance resulted by grade value of the track. More complete block section division program is going to be developed by the help of experienced experts.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.227-234
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• 2009

At present, the length of deceleration lane at freeway diverging areas are designed based on the design speed of main lines and ramps. This is possible on assumption that diverging vehicles decelerate at deceleration section after moving to shoulder lane in advance. But with high diverging volume, several vehicles will try to change to exit lane at the same time. This will cause the distribution of main lane flows or some vehicles may encounter short deceleration length because they miss the proper time to change the lane. The purpose of this study is to establish a design guideline of the length of deceleration section considering the volume of diverging traffic. Also, the results of analysis by the FRESIM simulation model shows that some improvements in respect of delays, speeds and speed deviations of mainline and deceleration lane.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1992.04a
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• pp.105-110
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• 1992

This study deals with the effect of a series of moving trucks on the Dynamic Load Factor (DLF). The DLF is calculated by investigating the load effect of moving trucks. Therefore, analytical models for frocks, bridge, and road profiles were developed and dynamic structural analysis computer program were developed. Then the DLFs are calculated as a ratio of maximum dynamic load effect and maximum static load effect. Trucks used in this study are 5 axle semi tractor-trailer with the weight of 36 and 54 ton. Simply supported prestressed concrete box girder bridges with 20 and 40m span length are selected. From the results of the DLF for various headway distances, they show a very scattered and relatively high values of the DLF in case of a 20m span length bridge. For a 40m span length bridge, the results show less scattered and small increase of the DLF compared to a 20m span length bridge.

• Journal of Korean Society of Transportation
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• v.12 no.1
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• pp.97-116
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• 1994

Today advanced traffic management systems are required because of a high increase in traffic demand. Accordingly, the objective of this study is to take advantage of image processing systems and present image processing methods available for collection of the data on traffic characteristics, and then to investigate the possibility of traffic flow analysis by means of comparison and analysis of measured traffic flow. Data were collected at two places of Daegu city and Kyongbu expressway by using VTR. Rear view (down stream) and frontal view (up stream) methods were employed to compare and analyze traffic characteristics including traffic volume, speed, time-headway, time-occupancy, and vehicle-length, by analysis of measured traffic flow and image processing respectively. Judging from the results obtained by this study, image processing techniques are sufficient for the analysis of traffic volume, but a frame grabber equipped with high speed processor is necessary as well, with low level system judged to be sufficient for traffic volume analysis.

• Journal of Korean Society of Transportation
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• v.9 no.1
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• pp.5-18
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• 1991

Two-Lane, two-way roads account for approximately 92% of total road length in Korea and accomplish the majority of regional transport activities. Nevertheless not too many research have been made on two-lane roads particularly efficiency related topics such as capacity and travel time studies. In this study a full scale data collection was conducted using video equippments on rural two-lane roads to determine capacity Passenger Car Equivalents(PCE) and Level of Service criterion. Various PC programs were utilized to reduce traffic data and Walker ME? and Headway Method were employed to determine PCE's for heavy vehicles. The reseach has shown that capacity and PCE's for two-land two-way roads in Korea are 3200 pcph and 1.1∼1.9 resectively. In addition percent time delay was used as the basis of developing Level of service criterion on two-lane roads in Korea.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.8
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• pp.390-396
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• 2003

This paper is focused on an optimal block sectioning technique which are widely used in conventional railway system. We studied braking distance with pure train braking performance to generalize train braking. We tried to apply the braking distance to wayside signaling system to decide optimal block sectioning to reduce headway. The braking distances are obtained for 2 aspects, 3 aspects, 4 aspects and n aspects such that step speed control, are longer than the pure braking distance. We found an optimal solution with the generalized n aspects, and a minimum block distance for ATO mode.