• Proceedings of the KWS Conference
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• 2006.05a
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• pp.157-159
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• 2006

This study used by high speed DSP for more developing capability of inverter GMA welding machine. It also is designed by high speed DSP GMA welding system for real time control and improve of welding capability throught the switching frequency control by using of high speed DSP.

• Proceedings of the Korean Statistical Society Conference
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• 2003.05a
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• pp.203-206
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• 2003

This paper studies constrained optimization of an M/G/1 queue with a server that can be switched on and off. One criterion is an average number of customers in the system and another criterion is an average operating cost per unit time, where operating costs consist of switching and running costs. With the help of queueing theory, we solve the problems of optimization of one of these criteria under a constraint for another one.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.3
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• pp.262-268
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• 1988

In this paper conditions are derived, which ensure the existence of a quasi-sliding mode on the control switching hyperplane in discrete variable structure control systems and also remove the reaching phase problem observed in continuous-time variable structure systems. In addition, a discrete variable structure tracking controller which has adaptive properties is devised based on these results. This controller has useful properties, such as small sensitivity to the variation of plant parameters and to disturbances and its performing speed is fast compared to that of other adaptive controller.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.303-306
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• 2002

The EMI filter used in switching apparatus is designed on the basis of personal designer experience. A try and error approach leads to a considerables waste of time without assurance to come out to a good solution. The difficulty in the right choice of the component values resides on the dominant role played by their parasitic components at high frequencies and is aggravated by the poor knowledge of the internal impedance of the noise generators. In this paper, we proposed the design technique for the EMI filter effectively using the LISN and the EMI analyzer in the industrial field.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1807-1809
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• 1996

The axial discharge at switching operations of EHV $SF_6$ disconnector can lead to the breakdown to the enclosure. Precursor in periphery zone leads to formation of leader over some time delay. Injected charge value depends on electric field and gap geometry. The calculation method for parameters of $SF_6$ insulation for DS in EHV-GIS is suggested by using the new criterion of leader inception in connection with periphery field nearby the boundary of streamer zone.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2006.06a
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• pp.303-310
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• 2006

The sorting algorithms have been developed to take advantage of distributed computers. But the speedup of parallel sorting algorithms decrease rapidly with increased number of processors due to parallel processing overhead such as context switching time and inter-processor communication cost. In this paper, we propose a parallel sorting method which provides linear speedup of an optimal serial algorithm for a system with a large number of processors. This algorithm may even provide superlinear speedup for a practical system. The algorithm takes advantage of an interconnection network properties and its protocol.

• Journal of the Korean Mathematical Society
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• v.34 no.3
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• pp.553-567
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• 1997

This paper is concerned with the control problem $$ \dot{x}(t) = F(x) + u(t)G(x), t \in [0,T], x(0) = 0, $$ where F and G are smooth vector fields on $R^n$, and the admissible controls u satisfy the constraint $$\mid$u(t)$\mid$ \leq 1$. We provide the sufficient condition that the bang-bang trajectories having different switching orders intersect.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.1-6
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• 1998

To achieve fast control action, direct control methods should be used. "Direct Mean Torque Control" (DMTC) combines the good dynamic performance of Direct Torque Control (DTC) with the advantages of inherently constant switching frequency and time equidistant control for implementation in a digital signal processor. Since DMTC is a predictive control algorithm, the model and its correction deserves special investigations. This paper proposes a steady-state Kalman filter which is well suited for fast computation.mputation.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.13 no.3
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• pp.225-236
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• 2009

Image inpainting is the process of reconstructing lost or deteriorated parts of images using information from surrounding areas. We propose a computationally efficient and fast phase-field method which uses automatic switching parameter, adaptive time step, and automatic stopping of calculation. The algorithm is based on an energy functional. We demonstrate the performance of our new method and compare it with a previous method.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.510-513
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• 1988

This paper describes an effective trunk loop signal processing method and analyzes execution time of program in the DTCP(Digital Trunk Circuit Processor) in the TDX-1A digital switching system. To predict a maximum trunk capacity, also analyzes to Z80A system clock(4Mbit/s, 2.5Mbit/s) and scanning period(8mS,5mS) respectively.