• Journal of the Institute of Convergence Signal Processing
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• v.3 no.3
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• pp.6-13
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• 2002

In this paper, we propose an image processing based method to measure red-time and green-time backward moving shockwave speed automatically at signalized intersections. Shockwave means the discontinuous boundary line between different vehicle traffic flows, and its moving speed is called shockwave speed which is obtain from the slope of boundary line. In this paper, we compose distance-time diagram for measuring shockwave speed automatically. By global vehicle tracking, we draw all of the vehicle moving path on distance-time diagram. We analyze the slope change pattern of curved moving path line, and compute red-time and green-time backward moving shockwave speed. We obtain the measurement result of shockwave speed, when applying above mentioned proposed method to experiment at signalized intersections, Once we can measure the shockwave speed, we could apply the result to highway ramp metering and automatic signal control at intersections effectively since we know the situation of frontal congestion easily.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.187-192
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• 2003

of the road would be a key index judged for a safety at the vehicle driving on the road. In Korea, as seen through a lot of documents, the vehicle driving speed is much faster compared with the design speed. The vehicle driving speed is an important element to get to know the vehicle driving characteristics. However, it is not easy to obtain the vehicle driving speed relating to vehicles' consecutive movements just merely through the presently used methods of vehicle driving speed. In consequence, this study has conducted photographing vehicle movements by use of digital moving images. Based on digital moving Images pictured, we have obtained a certain time interval frame and extracted out vehicles' coordinates and calculated vehicle speed from the firstly rectified image and the secondly rectified image. We could obtain comparatively exact results in the calculation of vehicle driving speed as errors of about 4%, as a result of comparison and verification of vehicle speed calculated from the digital moving images and the speed obtained from DGPS.

• Geomechanics and Engineering
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• v.32 no.5
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• pp.483-494
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• 2023

High-speed trains became common nowadays due to the need for fast and safe mean to transport goods and people. However, the use of high-speed trains necessitates the examination of the critical speed, which is the train speed at which the maximum settlement of the railway track occurs. The critical speed and railway track settlement have been investigated considering only one train in previous studies. However, it is normal to have two adjacent trains moving at the same time. This paper aims to understand how the interference of two moving trains affects the settlement and critical speed of ballasted railway track. Calibrated three-dimensional finite element models of railway track subjected to one moving train and two moving trains have been developed to address the aim of the study. It is found that the interference dramatically increases the railway track settlement with a percentage increase ranges between 5 and 100%. It is also found that the percentage increase of the railway track settlement depends on the train speed and the distance between the moving trains. In addition, it is found that the thickness of the ballast layer and the stiffness of the subgrade have minor influence on the percentage increase of the settlement. Importantly, the results of this paper illustrate the importance of the interference of the moving trains on the dynamic response of the railway track. Thus, there is a need to consider the dynamic interaction between the adjacent moving trains in the design of railway track foundation.

• Journal of the Korean Society for Railway
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• v.6 no.2
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• pp.129-134
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• 2003

This paper investigates the dynamic characteristics of a beam axially moving over multiple elastic supports. The spectral element matrix is derived first for the axially moving beam element and then it is used to formulate the spectral element matrix for the moving beam element with an interim elastic support. The moving speed dependance of the eigenvalues is numerically investigated by varying the applied axial tension and the stiffness of the elastic supports. Numerical results show that the fundamental eigenvalue vanishes first at the critical moving speed to generate the static instability.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.5
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• pp.15-25
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• 2000

The purpose of this paper is to examine the visual evaluation structure about the formal changes of streetscape by the different moving speed in two alternative control plans for the building height and the setback regulation. The virtual reality system is applied to the experimental tool. Eighty-two experimental models are made in consideration of the height and the setback of the building regulation cased by Midou-suji street in Osaka City, Japan. and ten typical models are selected by pre-experiment. Since the changes of the landscape structure consists of the height and the setback of the building, four the evaluation items are set: grade of continuity, order, openness, preference. As there are eighty-two landscape models which are too many to be applied in this experiment, ten role models are drawn out and used in this experiment. The mean difference test, discriminant analysis, and multiple linear regression methods had been used for the statistical analysis methods. The results of this study are as follows; 1) It is found out the fact of the difference evaluation structure amount experiments models. 2) From the sketch analysis and interview, it is found out difference cognition structure by the moving speed and alternatives. 3) From the discriminant and regression analysis, it is found out that the evaluation value about continuity becomes low by the moving speed change from walking speed to driving speed. We suggest that continuous experiment should be made with a variety of groups and models, and general and universal results should also be come out of the experiments above.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.125-130
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• 2002

This paper investigates the dynamic characteristics of a beam axially moving over multiple elastic supports. The spectral element matrix is derived first for the axially moving beam element and then it is used to formulate the spectral element matrix for the moving beam element with an interim elastic support. The moving speed dependance of the eigenvalues is numerically investigated by varying the applied axial tension and the stiffness of the elastic supports. Numerical results show that the fundamental eigenvalue vanishes first at the critical moving speed to generate the static instability.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1092-1099
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• 2011

This paper is concerned with the ATO speed profile generation method in the moving block system. The ATO speed profile is calculated using the acceleration limit and the jerk limit to improve ride comfort. In addition, the speed limit and stop distance provided from ATP profile should be considered to ensure safety. In the moving block system, the speed limit and the stop position are frequently changed in real-time. Therefore, the ATO speed profile should be regenerated immediately according to change of the speed limit and the stop position, within the acceleration limit and the jerk limit. In this paper, the ATO speed profile generation method is proposed, which considers not only frequent changes of the speed limit and the stop position but also acceleration limit and jerk limit. Futhermore the simulation result is presented to verify usefulness of this method.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.87-94
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• 2002

In order to manufacture a precision mold/die by machining, users need high speed ＆ precision mold/die machining center. So, for development of this machine, we intend to use linear motor that is instead of ball-screw, servo-motor and coupling, high-speed spindle of pressurized air journal bearing and composite materials. In this paper we research column moving type and table moving type. The former is mainly piling 3 axes on one moving body, the latter is consist of two independent carriages. Both types are available to high speed & precision machine, but we finally draw a conclusion column moving type due to an advantage of high-speed control of linear motor.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.96.6-96
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• 2002

In this study an image processing system is designed and developed, which can detect and assort some defects on the surface of an object moving with high speed. For real time surface detection of high speed moving object, the fast processing should be managed and the image information including some surface features should be captured. It is difficult to acquire the noise free image due to various light sources and high speed moving materials under the environment of the general industrial site. In general, because pre-processing methods are employed for getting a noise free feature, the image processing speed has some limitation and the expensive image processing devices are required. This...

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.688-692
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• 2000

This study proposed design parameters of opening spring of circuit breaker that cut off the over-current in order to protect the electric device about opening speed using the energy method. We simulated the opening kinetic energy, the potential energy of opening spring and the design parameters of opening spring with respect to opening speed of VCB (Vacuum Circuit Breaker)'s moving contactor which has 24kV 25kA break capacity. From the result of simulation the initial tensional force and the final tensional force of the opening spring chose 107kgf and 282kgf respectively. Through the dynamic analysis using ADAMS, We verified that the opening speed of moving contactor satisfied break capacity of VCB and analyzed opening dynamic characteristics of VCB such as the opening displacement, the opening velocity and the opening acceleration of moving contactor in time domain.