• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1175_1176
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• 2009

In comparison with different mass transportation systems, the streetcar is lower, both in speed and transportation capacity. However, it has the advantage of reducing the cost of construction, because it makes infrastructure simple, by using the road. It is proper in the city, where the population is few, to raise the efficiency of traffic. The convenience is high to passengers. On time accuracy and the commercial speed is influenced by operating condition. Generally that is organized into 21m degree in 6 quantity. All passengers in a streetcar are about 180 people. The maximum speed is 40~60km/h. When road traffic is considered, the speed can be reduced to 15km/h. To enhance the speed, the construction of a priority signaling system is necessary which is integrated with the road traffic operation information system. In order to develop a better Traffic Control System which is connected to a Traffic Control Center, a Priority Signaling System which incorporates Intersection Control Technics must be included.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.694-697
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• 1997

As the life cycle of the vehicle become shorter, the method that reduce the development time of new model become more important. In this reason, the development of the simulator that provides similar environment with the actual vehicle load characteristics is increasing. In this paper, the link unit of the 3-axis road simulator is designed and simulated with dynamic analysis software ADMS. and the maximum stress and strain are analyzed for the safety of link and specifications of optimal design using finite element method.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.303-303
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• 2000

It is difficult to determine the static axle weight of a vehicle with weigh-in-motion systems which in absence measure instantaneous axle impact forces. The difficulty in determining a static axle weight results from dynamic effects induced by vehicle/road interactions. One method to improve the problem is to quantify a statistical confidence level for measured axle weight. The quarter-car model is used to simulate vehicle motion, Also, the road input to vehicle model can be characterized in statistical terms by PSD (power spectral density) of appropriate amplitude and frequency contents other than an exact spatial distribution. The confidence levels for the measured axle weight can be obtained by the random process analysis using both vehicle model and road input.

• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.125-130
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• 2004

It is not difficult to see the road repairing. There are many and various machines that can crush road surface. The efficiency and power of the machine depend on crushing head-shape, crushing interval, crushing load, crushing stress, machine's dropping height and roller's kind. The objective of this study is to select the optimal model among ten models of crushing machine with constraints such as crushing depth, variation, and crushed particle size. The data for this study are chosen from the site of construction in Kangnung during three months ($2004.\;6.\;1\;\sim\;2004.\;8.\;31$). The provided methodology in this paper will be fruitful not only for the selection of crushing machine but also for the aspects of construction period, cost, work efficacy according to the condition from the various sites of construction.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.211-219
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• 2003

The main study experiments to obtain engine torque of the vehicle during performance test of the recent automobile. Torque was measured through the engine dynamometer to produces engine torque of the vehicle but the research method calculated engine torque of the vehicle without the engine dynamometer. The performance of the vehicle receive various running resistance. The study certificates performance of certification before a certification of used vehicle didn't carry out and certificate. This way evaluated on road test and chassis dynamometer The result of the study shows that it is much possible to apply the test. After comparing the engine torque of road driving with that of chassis dynamometer, the results are approximately the same. When rapidly speeded up, the road-load vehicle can pitch in some degrees, which may result in the fluctuations of acceleration, and then affect on the engine torque. Therefore it is confirmed that this method is easier way to measure the performance of vehicles.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.139-147
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• 2004

The purpose of engine control TCS is to regulate engine torque to keep driven wheel slip in a desired range. In this paper, engine control TCS using sliding mode control law based on engine model and estimated load torque is proposed. This system includes a two-level controller. Slip controller calculates desired wheel torque, and engine torque controller determines throttle angle for engine torque corresponding to desired wheel torque. Another issue is to measure load torque for model based controller design. Luenberger observer with state variables of load torque and engine speed solves this problem as estimating load torque. The performance of controller and observer is certificated by simulation using 8-degree vehicle model, Pacejka tire model, and 2-state engine model. The simulation results in various maneuvers during slippery and split road conditions showed that acceleration performance and ability of the vehicle with TCS is improved. Also, the load torque observer could estimate real load torque very well, so its performance was proved.

• International Journal of Railway
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• v.8 no.1
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• pp.5-9
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• 2015

Reliability based limit state design method is replacing traditional deterministic designs such as allowable stress design and/or ultimate strength design methods in world trends. European design code(Eurocode) has adopted limit state design, and Korea road bridge design standard has also recently been transferred to limit state design method. In this trend, Korea railroad design standard is also preparing for adopting the same design concept. While safety factors are determined empirically in traditional design, load combinations as well as load factors are determined by solving limit state equations. General partial safety factors are evaluated by using AFORM(Advanced First Order Reliability Method) in the reliability based limit state design method. In this study sensitivity analysis is carried out for a dead load factor and a live load factor. Relative precisions of the dead load and the live load factors are discussed prior to the AFORM analysis. Furthermore the sectional forces of design and the material quantities required by two different design methods are compared for a PSC box girder railway bridge.

• Journal of the Society of Disaster Information
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• v.12 no.1
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• pp.40-46
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• 2016

Nowdays, adjacent loading bringing enormous harm to the existing bridge in engineering construction. In this paper, the influencing mechanism of adjacent loading to pier and Law of displacement of pier is researched through living examples, and the safe influence area has been defined. Research shows that: the main damages to piers is caused by the side loading; lateral displacement index of pier top surface is more conservative than the pier additional stress index; it is secure when the distance of adjacent load is 0.5 times of the height of accumulation or 6m, otherwise it would be very scary, and the monitoring measure is necessary.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.29-36
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• 2012

In this study, frequently passing vehicles with two, three, four, and five axles were chosen through traffic volume analysis in Kyung-In Expressway in order to analyze how the road roughness and vehicle speed affect on the dynamic loads for roads in various vehicle classes. Dynamic loads according to chosen vehicles are estimated by TruckSim program. Dynamic load amplification factor is ratio between dynamic and static loads, and it is also determined for each vehicle classes. From the result of dynamic loads estimated by the dynamic load amplification factor, it is shown that for three-axles vehicle, when IRI is 3.5 and vehicle speed is 100km/hr, asphalt pavements receive additional 36% of static loads in maximum. The analysis of the amplification factor according to each vehicle classes also indicates that the amplification factor increases as the distance between the axles becomes smaller and each axle receives more loads.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.4
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• pp.647-657
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• 2017

The main purpose of this study is to investigate the static & dynamic behavior of a precast bracket under precast road deck slab of double deck tunnel. In order to improve the construction speed, the field prefabricated bracket to connect the intermediate slab to the precast shield tunnel lining structure has been developed in the 'SPC (Steel Precast Concrete) bracket'. The experiments were performed for the full scale model in order to evaluate the performance of the 'SPC bracket', the structural stability was verified through the FEM analysis. The result of static loading test, no deformations or cracks of the bracket undergo the ultimate load was investigated. In addition, no pulling or deformation of the chemical anchor for fixing the bracket was measured. As a result of dynamic loading test, it was investigated that there is no problem in the chemical anchor for fixing the bracket. FEM analysis showed similar behavior to static load test and it was determined that there is no problem in serviceability and structural safety.