• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.829-835
• /
• 2007

For constant operation, Electric Railway System has many electrically divided parts of the trolley lines to avoid error spreading. FRP-Section have a role to divide Catenary trolley lines electrically. If one electric train approach to the section at the same time with partial power failure, the pantograph of train can make a short circuit with supplied part to failure part. Electric arc induced with this switching effect, can break FRP-section, and there are such error cases. In this study, we propose one method to prevent FRP-section breakdown from these reason, with detecting sensor at the sectional position.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.1324-1329
• /
• 2007

For the commercialization of the urban maglev, an articulated turnout which consists of several segments of turnout girders and where switching is done by rotating those segments is under development. In this paper, to determine the alignment of this articulated turnout, the requirements for the alignement are analyzed. Requirements include: those for the levitation control and for the ride comfort. For the levitation control, rail joint width should be limited to a certain value, and for the ride comfort, the lateral acceleration and the time derivative of the lateral acceleration satisfy a guideline. According to these requirements, the alignment criteria are discussed.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.1386-1391
• /
• 2007

The ballast gravels are often contaminated by various pollutants, like diesel fuel, lubricants, and heavy metals. Especially, the gravels near the switching are apt to be polluted by the lubricant. Because this lubricant can pollute the soil of track, the contaminated ballast gravels should be cleaned immediately. In this study, a physical desorption method was used to remove the oil contaminants from the surface of the ballast gravels. Thermosetting resin was used as a media for physical remediation of ballast gravels. The total petroleum hydrocarbon of the gravels was monitored over time. In addition, scanning electron microscopic images were obtained to observe the removal of the oily pollutants from the surface of the gravels.

• Journal of the Korea Society for Simulation
• /
• v.9 no.1
• /
• pp.11-19
• /
• 2000

The main idea behind the Intelligent Networks (IN) concept is the separation of switching function from the service control, in order to meet various service requirements of subscribers and development of new services in time. The (N+l) architecture of the IN service system consists of front-end processors (FEP) and back-end processors (BEP), which is in service in a domestic telecommunication company, and balances the traffic load for services among the processors. Under this architecture, the IN service system can distribute the traffic load dynamically, and M services are easily launched and manipulated minimizing impacts on the existing services. This paper traces the performance of the (N＋1) structured system by means of the simulation approach, and shed a light on the result.

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2000.11a
• /
• pp.23-27
• /
• 2000

Simultaneous Switching Noise (SSN) propagated through parallel power and ground planes in high-speed multilayer printed circuit boards (PCBs) causes malfunction of both digital and analog circuits. To reduce SSN, decoupling capacitors are generally used in the PCBs. In this paper, we improve the equivalent circuit model of decoupling capacitor in high-frequency range to analyze the effect of SSN reduction accurately. The analysis is performed by the microwave and RF design system (MDS) method and the finite difference time domain (FDTD) method. We compared the results by the ideal capacitor model with those by the proposed model.

• Transactions on Control, Automation and Systems Engineering
• /
• v.2 no.2
• /
• pp.98-103
• /
• 2000

This paper is concerned with a delay-dependent sliding mode scheme for the robust stabilization of input-delay systems with bounded unknown uncertainties. A sliding surface based ona predictor is proposed to minimize the effect of the input delay. Then, a robust control law is derived to ensure the existence of a sliding mode on the surface. In input-delay systems, uncertainties given during te delayed time are not directly controlled by the switching control because of causality prolem of them. They can influence the stability of the system in the sliding mode. Hence, a delay-dependent stability analysis for reduced order dynamics is employed to estimate maximum delay bound such that the system is globally asymptotically stable in the sliding mode. A numerical example is given to illustrate the design procedure.

• Journal of Institute of Control, Robotics and Systems
• /
• v.14 no.9
• /
• pp.963-968
• /
• 2008

A new method to deal with GPS indoor positioning by means of time synchronized switching GPS repeater has been developed by authors[1]. But the developed indoor positioning system has problems. Therefore, we proposed a method for indoor positioning using GNSS Repeater-Assisted. To solve the 3-dimensional user's position, the 4 or more retransmission antennas are needed in the previously proposed methods. If a GPS repeater periodically transmits the signal like as pseudollite, the information for assisting an acquisition and tracking can be informed to receiver. Then, the user position can be calculated using the induced weak signal. The advantage of the proposed algorithm is use of only 1 re-transmission antenna because the re-transmitted signal are not used for positioning but used for assisting an acquisition and tracking weak signals induced indoor. We analyze the propose algorithms through the experiment and performed the test of feasibility.

• Proceedings of the IEEK Conference
• /
• 2002.06e
• /
• pp.51-54
• /
• 2002

As digital systems continue to use components with faster edge rate and clock speeds, transmission of the digital information can take place many troubles. The increasing requirement for controlled impedance PCBs becomes both a critical success factor and a design challenge. Especially, the noise sources in digital system include the noise in power supply, ground and packaging due to simultaneous switching of signal, signal reflections and distortions on single and multiple transmission lines. This paper simulates the tracks controlled impedance with the test coupon. So, it can saves the design time and supports the economical PCB design.

• Proceedings of the IEEK Conference
• /
• 2002.06e
• /
• pp.211-214
• /
• 2002

Under a continuous manufacturing process, two dimension inspection system causes problems as blurring effect and low resolution and requires position calibration between frames. One dimension inspection system is, therefore, being researched as a substitution. In this paper, we implement mechanism of switching memory and processing data for reasonable one dimension inspection system. Redundant weft image and noise was suggested to be reduced by new method using modified morphological process and masked erosion process. From resulting image, line data and possible error information were obtained and constructed as a structure. Finally, error detecting algorithm was performed with this data structure. Processing time of error detecting was 0.625ms per line in applied system and experiment showed 94.7% of error detecting ability. This method is 20% faster in speed and 2.7% higher in error detecting ability comparing with the present method.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.1
• /
• pp.60-67
• /
• 1998

In this paper, a gain scheduling method of PID controller is proposed using fuzzy logic for balancing control of an inverted pendulum. First, gains of PID controller are calculated using pole-placement technique for the linearized model of an inverted pendulum and these gains are modified by fuzzy logic throughout control operations. A PD controller is used by switching near the set-point to improve the performance. It is illustrated by simulations that the proposed hybrid fuzzy control method yidels smaller rising time and overshoot compared to the fixed-gain PID controller or fuzzy logic-based only PID controller.