• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.355-360
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• 2019

In this study, the structural stability of the railway level crossing system using rubber panel for high speed lines was investigated by applying the specification for wind load conditions (Train gust) of high speed train (300km/h and 360km/h). A finite element analysis using three-dimensional modeling was carried out by applying the field conditions that was installed with the complicated configuration of the rubber plate panel system. As a result of this study, the structural stability of the rubber plate panel system for high speed train gust was analytically verified.

• Journal of the Korean Society for Railway
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• v.8 no.2
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• pp.145-154
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• 2005

Traffic accidents at highway-rail crossing result in larger social and economic damages than the accidents at the typical highway intersections. The traditional control and warning systems of the highway-rail crossing have limitations in that 1) they do not recognize the differences of the trains' arrival times because they rely on the distance-based control system, rather than the time-based one, and 2) thereby they usually cause longer delays of vehicles and pedestrians at the highway-rail crossings. The objective of this study is to develop a time-based railroad crossing control system which takes into account the speed and expected arrival time of trains. using the spot speeds and acceleration rates of trains measured at three points, the developed system was found to be able to accurately estimate the arrival time of train. VISSIM simulation package was utilized to compare system effect of the developed time-based railroad crossing control system with that of the conventional distance-based one. It was found that the developed time-based railroad crossing control system reduced the average travel time, maximum delay length, average delay time, and average number of stop-experienced vehicles as much as 7.0$\%$, 75.6$\%$, 12.7$\%$, and 60.0$\%$, respectively, compared with those from the conventional distance-based one.

• Journal of Korean Society of Transportation
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• v.13 no.2
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• pp.43-58
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• 1995

This paper discusses some of the results of investigation of railroad-highway grade crossing accidents and accident-related inventory information that was collected from the Pusan District Office of the Korean National Railroads. Established statistical techniques were applied to tabulated data to obtain an accident prediction equation that estimates the expected probability of accidents at each crossing under various grade crossing situations. It was found that the most significant factor that influences the railroad crossing accidents was flagger. The other factors were train and traffic volumes, number of tracks. crossing angle, maximum timetable train speed, algebraic grade difference, and lighting facility. No significant effects was identified with railroad crossing gates. The results of the analysis and the uses of the prediction equation for the development of warrants for safety improvements are also discussed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.88-91
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• 2007

Turnout system is a mechanical installation enabling trains to be guided from one track to another which is consists of point blades, common crossing and guard rail etc. These structural feature causes vibration, noise and damages while railroad car wheel is passes by. A tilting train is a train with a tilting mechanism that enables increased speed on regular railroad tracks. The aim of this paper is to study a characteristics of the shock-vibration and noise of tilting and existing train passes by turnout systems. To analyze and assesment, noise and vibration measurement was carried out at the Naesu-station of Chungbuk-line which equipped with cast manganese crossing and built-up crossing and Illo-station of Honam-line which equipped with cast manganese crossing.

• Geomechanics and Engineering
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• v.20 no.2
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• pp.103-112
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• 2020

The dynamic response of crossing tunnels under heavy-haul train loads is still not fully understood. In this study, based on the case of a high-speed tunnel underneath an existing heavy-haul railway tunnel, a model experiment was performed to research the dynamic response characteristics of crossing tunnels. It is found that the under-crossing changes the dynamic response of the existing tunnel and surrounding rock. The acceleration response of the existing tunnel enhances, and the dynamic stress of rock mass between crossing tunnels decreases after the excavation. Both tunneling and the excitation of heavy-haul train loads stretch the tunnel base, and the maximum tensile strain is 18.35 µε in this model test. Then, the measured results were validated by numerical simulation. Also, a parametric study was performed to discuss the influence of the relative position between crossing tunnels and the advanced support on the dynamic behavior of the existing tunnel, where an amplifying coefficient of tunnel vibration was introduced to describe the change in acceleration due to tunneling. These results reveal the dynamic amplifying phenomenon of the existing tunnel during the new tunnel construction, which can be referred in the dynamic design of crossing tunnels.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.5
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• pp.352-359
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• 1987

The cycloconverter operating on a circulating current-free mode has many zero crossing points. If an exact zero crossing points are not detected, the three phase-unbalanced currents will flow in a motor. In this paper, the current feedback using a current reference wave is proposed to improve the problems of zero crossing detection, three phase-unbalanced voltages, currents, and torgue ripples. To prevent the saturation of the air gap flux and keep the torque constant, the constant voltage / hertz control with IR compensation is adopted. The PI-controller is designed using the linearized model of the cycloconverterinduction motor system. Alsi, Z-80A single board computer has been used to implement the proposed scheme which results in the performance improvement of cycloconterter-fed induction motor speed control system.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.163-169
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• 2003

In order to develop domestic railway technology, it is necessary that manufacturing technology of turnout should be kept up with update level, because turnout is the core component of high speed railway. Manganese crossing made of high manganese alloy steel is a important component of turnout. So far, this could not have been welded with rail steel due to metallic problem in Korea. However, joint technology hereunder between manganese crossing and rail by using Flash Butt Welding which is developed by Kangwon Railtech Co., Ltd is the state of the art and enable to realize rail continuousness in turnout section, speed up train velocity, reduce maintenance cost, and enhance riding quality.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.321-324
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• 2001

The accidents in a railway level crossing where passengers or vehicles pass on the track went through by the train with a inherent high rate on incidents lead to a vast economic damage on people and material resources. So, many protection equipments are placed on the railway crossing to prevent those kind of accidents. But there is a limit to control driver's rough activity, passenger's careless or an intentional accident. This study is trying to ensure the safety in railway crossing by providing the information on train's speed and expected passing time on the railroad to a road traffic control system or car driver. Additionally, this system has been studying the railway level crossing system concerning ITS to support harmonious traffic flow.

• Dementia and Neurocognitive Disorders
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• v.22 no.4
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• pp.139-147
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• 2023

Background and Purpose: Dual walking task such as crossing over an obstacle may serve as an excellent tool for predicting early cognitive decline. Thus, this study aimed to investigate correlation between walking while crossing over an obstacle and executive functions under different gait phases to validate the use of walking with an obstacle for predicting early cognitive decline. Methods: A cross-sectional study was conducted on 48 elderly individuals from 2 day-care centers and 3 welfare-centers in Seoul and Gyeonggi, Korea. Executive function tests (Trail Making Test, Stroop test) and dual walking tests (gait speed, cadence, stance time, gait cycle time) were performed and compared using partial correlation analysis. Results: There were significant correlations between executive function and most of the gait variables (stance time, cadence, and gait cycle time) (p<0.05) when crossing over an obstacle while walking. Especially, stance time exhibited significant correlations with most executive functions (p<0.05). Conclusions: When evaluating executive function during walking with an obstacle, post-obstacle-crossing phase and stance time need to be observed.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.2
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• pp.141-149
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• 2010

It is essential to find oscillating angles and periods in a seaway when designing and manufacturing stabilizers. It is difficult to find oscillating angles and periods in high speed turning and they vary with ship speed and wave heading angles, therefore, proper algorithm to measure oscillating periods in a seaway. In the present study, three kinds of algorithms are developed to measure oscillating angles periods in a seaway. Dual axis tilt sensor of low price is used to measure oscillating angles, and the effect of lateral accelerations on tilt sensor have been reduced by the fusion algorithm using the gyro sensor signals. Analog and digital filters are applied to minimize the noise of the signals. Three kinds of algorithms, zero crossing, peak to peak and moving zero crossing algorithm, are developed to measure oscillating periods in a seaway. It is found that the moving zero algorithm showed the best results in the sea trials.