• Proceedings of the KSR Conference
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• 2004.06a
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• pp.608-612
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• 2004

Safety from derailment has been evaluated according to the magnitude of the derailment coefficient, which does not always ensure sufficient safety evaluation, and is not necessarily helpful in clarifying the mechanism of derailment. When wheel rolls, point of contact between wheel and rail was change continuously and flange touches with rail. Established gauge so that can measure location of contact point between wheel and rail by strain gauge. Also, wish to describe result that compose bridge circuit and execute load test.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1093-1098
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• 2002

Dynamic behaviors of the Korean High-speed Train(KHST) have been analyzed to investigate the performance on the stability, the safety and the ride comfort. Multi-body dynamics analysis program using Recursive method, called RecurDyn, have been employed in the numerical simulation. To model the wheel-rail contact, the RecurDyn uses its built-in module which uses the square root creep law. The accuracy of the rail module in RecurDyn. however, decreases in the analysis of flange contact because it linearizes the shape of the wheel and rail. To solve this problem, a nonlinear contact theory have been developed that considers the profiles of the wheel and rail. The results show that the KHST still needs more stability. The problem should be solved by the examinations of module and modeling.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.222-231
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• 2003

After the reform of rail industry, a system to evaluate service qualities is required for the continuous improvement of railway service and the strength of competitiveness. This research provides evaluation categories and indices which are considered to be suited to the evaluation of rail service qualities. This study provides 4 categories and 11 indices to assess the rail service qualities: provision-operation interval/average operation speed, reliability-regularity/operation cancellation rate, safety- train usage term/facilities for the weak, client satisfaction- easiness of reserving and purchasing of tickets/comfort of queuing facilities/ kindness of train crews/ pleasantness of trains/provision of information, etc.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.786-790
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• 2006

Urban rail transit offers target performance and function because various lower part system such as rolling-stock, signal, power and trackis consisted as complex. In order to function properly an urban rail transit which is complicated system to work as safety and reliability, System must secure safety with structure, design, manufacture, install and verification and it is important to establish a safety standard follows it procedures, establish what step all it is important to operate. Safety standard of urban transit infrastructure is minimum standard necessary to secure safety of signal, power and track. Urban rail transit standard business leads to make many requirements. Recently, many types of equipment have applied to manage requirements and standards for system efficiently in part of universal, airline and car accordingly applied equipments use to manage a pursuit(Trace) between standard of system. Especially importance of management is emphasized more become more. Importance of standard management which usesa computing support tool recently in transit filed is embossed and is predicted to be more such forward. Therefore we propose the effective method of management with infrastructure system by constructed data-base system.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1946-1950
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• 2007

Switch rail is a very important part on the railway track, which not only accounts for the safety of the passing trains but also greatly influences the speed of the train. The higher the speed and the loads of the train the more it demands on the properties of the switch rail. Research shows that the higher mechanical properties of switch rail the longer the service life. Induction heat treatment is a good way of improving the mechanical properties of metallic materials. But the switch rail's section area changes gradually across the lengthways, which is difficult for induction heating especially for the small section. And the mechanical property of small section of the switch rail is the most important for its service life. The induction heat treatment used past always brings the low hardness on small section which can cause low service life of switch for wearing, or too high hardness because of martensite microstructure which can cause the shelling or even breaking of the switch rail. To prolong the service life of switch rail by higher mechanical properties, we researched the improved induction heat treatment for switch rail by adjusting speed of heating, and adopting compressed air cooling. The results showed that switch rail obtain almost the same high hardness across the length way after the improved induction heat treatment, which is very helpful to extend the service life of switch rail.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.674-678
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• 2003

This research is develop the sensing and measurement technology for measure that wheel/rail interaction force to use laser. Investigated existent laser measurement system, and examined transformation by load that action to wheel for achieve research purpose. A proposed to laser measurement system composition plan to analyze existent method that measure wheel/rail interaction force.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1264-1269
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• 2006

Measurement and estimation of rail irregularity is an important factor to concern travelling safety of train. Now a day, rail irregularity have been measured by EM120 and ROGER 1000K imported from MERMAC Co. Italy and making researches actively in Korea. This paper mainly consider to find correlation between acceleration value of wheel axle in HSR350x and rail irregularity value measured by EM120.

• Smart Structures and Systems
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• v.29 no.4
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• pp.625-640
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• 2022

Maglev rail joints are vital components serving as connections between the adjacent F-type rail sections in maglev guideway. Damage to maglev rail joints such as bolt looseness may result in rough suspension gap fluctuation, failure of suspension control, and even sudden clash between the electromagnets and F-type rail. The condition monitoring of maglev rail joints is therefore highly desirable to maintain safe operation of maglev. In this connection, an online damage detection approach based on three-dimensional (3D) convolutional neural network (CNN) and time-frequency characterization is developed for simultaneous detection of multiple damage of maglev rail joints in this paper. The training and testing data used for condition evaluation of maglev rail joints consist of two months of acceleration recordings, which were acquired in-situ from different rail joints by an integrated online monitoring system during a maglev train running on a test line. Short-time Fourier transform (STFT) method is applied to transform the raw monitoring data into time-frequency spectrograms (TFS). Three CNN architectures, i.e., small-sized CNN (S-CNN), middle-sized CNN (M-CNN), and large-sized CNN (L-CNN), are configured for trial calculation and the M-CNN model with excellent prediction accuracy and high computational efficiency is finally optioned for multiple damage detection of maglev rail joints. Results show that the rail joints in three different conditions (bolt-looseness-caused rail step, misalignment-caused lateral dislocation, and normal condition) are successfully identified by the proposed approach, even when using data collected from rail joints from which no data were used in the CNN training. The capability of the proposed method is further examined by using the data collected after the loosed bolts have been replaced. In addition, by comparison with the results of CNN using frequency spectrum and traditional neural network using TFS, the proposed TFS-CNN framework is proven more accurate and robust for multiple damage detection of maglev rail joints.

• 전자공학회논문지 IE
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• v.44 no.2
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• pp.41-46
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• 2007

In this paper, we have proposed Station Safety Management System to protect station accident. we establish a sensor part near an underground rail. If a passenger approaches an underground rail, at first, lamp is shining and warning sound is ringing. nevertheless he approaches end of underground rail, At the same time, lamp is shining, warning sound is ringing, this information transfer server and train using wireless LAN. We makes this system using low cost in comparison with another system.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.581-585
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• 2004

The purpose of this study is to suggest a method to support decision making of researchers, when we estimate the safety of the high-speed railway using F-AHP. To apply this method, Korean type of high-speed railway was engaged, and the 8 Stages of accident type and the five criteria were suggested that we must meet. Then, the interview with the researchers working for high-speed railway was used to confirm the alternatives suggested. The employed F-AHP for this study estimate using emotional words based on AHP of Saaty, so it is very good to estimate the high-speed railway safety.