• Proceedings of the KIEE Conference
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• 1986.07a
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• pp.293-295
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• 1986

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.99.5-99
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• 2001

This study presents a simulation of the traction return current based on $2{\times}25kV$ power supply system in order to determine the impedance bond intensity of impulse type track circuit on the electrified Gyeongbu line. The results of the simulation enables us to measure the precise intensity of catenary current that returns to the substation through KTX (Korean Train Express) operated by $2{\times}25kV$ power supply system with common earth network. The combination of $2{\times}25kV$ and common earth network established on the electrified Gyeongbu line for the first time in Korea. We show that the relationships among the traction return current, earth current, and catenary current, and catenary current can be applied to this line in order to determine the optimal impedance bond intensity ...

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1175-1178
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• 2004

On-line partial discharge(PD) monitoring system has been developed to monitor in operating large motor stator insulations. This system makes use of remote diagnosis techniques for the evaluation of PD activity in the control center of thermal power plant. This system can be remotely accessed via a modem to build database, analyze status and interpret the pattern of PD activity. A personnel computer is generally connected to ten motors to continuous measurement of the PD activity. The test data can be easily interpreted by a maintenance staff. For assessing the condition of stator winding in motors, this system ensures a reliable measurement and accurate estimation. Capacitive couplers used for on-line PD measurement have been 80pF. The maximum PD magnitude(Qmax), PD pattern and normalized quantity number(NQN) were performed by this system.

• The Journal of Engineering Geology
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• v.24 no.2
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• pp.171-178
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• 2014

In seismic reflection data processing, the crossdip correction effectively focuses the stacking energy near the sharp bends of a crooked survey line. Additionally, approximate 3-D information on the reflector (e.g., true crossdip angle and lateral continuity) are locally investigated as a by-product of the crossdip correction procedure. Improvement of the signal-to-noise ratio and estimation of reflector crossdip attitude are tested, in terms of both common midpoint bin direction and processing-line type, using synthetic seismic reflection data. To effectively image the reflection energy near bends in seismic survey lines, straight-line binning is preferred to slalom-line binning.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.213-216
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• 2006

During the last decade several different methods have been proposed for the estimation of thermal deformations in the line heating process. These are mainly based on the assumption of residual strains in the heat-affected zone or simulated relations between heating conditions and residual deformations. However these results were restricted in the application from the too simplified heating conditions or the shortage of the data. The purpose of this paper is to develop a simulator of thermal deformation in the line heating using the artificial neural network. Two neural network predicting the maximum temperature and deformations at the heating line are studied. Deformation data from the line heating experiments are used for learning data for the network. It was observed that thermal deformation predicted by the neural network correlate well with the experimental result.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.4
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• pp.446-456
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• 2024

This paper addresses a novel approach to performance enhancement of the naval gun fire control system(FCS) by using the projectile tracking filter without any distortion of radar measurements. Under the assumption that the maneuvering between the projectile and the ship equipped with the radar is not quite large, this method is based on the concept of polar-coordinate target tracking, which separates the range estimation filter and the direction cosine estimation filter. Note that using polar-coordinates allows tracking to be performed in the same coordinate system from which the radar line-of-sight(LOS) measurements are obtained, unlike the conventional tracking process in Cartesian. Also, it is easy to implement in real-time and guarantees consistent estimates due to its linear filter structure. With the help of the above method, therefore, the proposed filter is able to improve the overall performance of FCS which requires stability of projectile estimates within a short engagement time. The effectiveness of the presented scheme is validated through computer simulations.

• Journal of Power Electronics
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• v.5 no.4
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• pp.282-288
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• 2005

In this paper, a new speed sensorless induction motor scheme which can estimate rotor speed and rotor resistance simultaneously is presented. The rotor flux with a low frequency sinusoidal waveform is used to conduct on-line simultaneous estimation of the rotor speed and rotor resistance. Hence the proposed sensorless control method is robust to rotor resistance variations. Also, the control scheme has no current minor loop to determine voltage references. It contributes to good control performance at low speeds. Some simulation results supported by experiments are given to show the effectiveness of this method.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.915-923
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• 2023

As environmental regulations on carbon emissions are strengthened worldwide, the existing internal combustion engine-centered automobile industry is being reformed. In particular, large buses and large cargo trucks are pointed out as one of the main causes of environmental destruction due to excessive carbon emissions. The E-Highway power collection system, which has recently been proposed as a solution, uses the vehicle's battery as a backup power source or regenerative braking, depending on whether the pan head of the pentograph installed in the vehicle is in contact with the overhead line. It is used to store the excess energy generated. However, wear through contact due to continuous contact reduces the current collection effect and causes failure. In this paper, by using the current difference, the horizontal position information of the panhead in contact with the overhead line is acquired, thereby reducing the abrasion of the conductor and the panhead Make it possible to follow the overhead line. The position estimation method proposed in this paper simply configures a device that can detect the position of the overhead line of the pantograph by the difference in resistance. It is economical and has the advantage of reducing the volume. The characteristics of the pantograph estimating the location of overhead lines were analyzed using the difference between the two currents of the current collector, the feasibility of the positioning estimation system was verified through simulations and experiments.

• Journal of information and communication convergence engineering
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• v.7 no.4
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• pp.545-550
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• 2009

A method fully utilizing multiscale line filter responses is presented to estimate the point spread function(PSF) of a CT scanner and diameters of small tubular structures based on the PSF. The estimation problem is formulated as a least square fitting of a sequence of multiscale responses obtained at each medical axis point to the precomputed multiscale response curve for the ideal line model. The method was validated through phantom experiments and demonstrated through phantom experiments and demonstrated to accurately measure small-diameter structures which are significantly overestimated by conventional methods based on the full width half maximum(FWHM) and zero-crossing edge detection.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.371-376
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• 1994

This paper presents an on-line modeling method approach for the machine condition. the machine condition is continuously monitored with a sensor such as, a vibration, a current, an acoustic emission (AE) sensor. In this study, neural network modeling by radial basis function is designed for analysis a prediction error. An on-line learning algorithm is designed using the RLS(recursive least square) estimation and the existing clustering method of Kohonen neural network. Experimental results show that the proposed RBNN modeling is suitable for predicting simulated data.