• Journal of Power Electronics
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• v.11 no.1
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• pp.51-58
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• 2011

In this paper, a function model of back-to-back PWM converters, based on the switching function, is developed for simplified simulation of power electronic application systems. For the function model, the PWM power switches are represented by dependent power sources. By using the proposed function model, the computer memory and the run time required for the simulation of power circuits can be significantly reduced. It is shown that the simulation results generated from the function models are almost the same as the ones obtained by using the switching power device model.

• Proceedings of the KIEE Conference
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• 1979.08a
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• pp.26-28
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• 1979

The optimal selection of Prime Implications for the multi-output switching function is difficult task, as the input variables increase. This paper is concerned with the technique for the minimization of the multi-output switching function using the intersection table. This procedure is applicable to both manual and computer-programmed realization without complexity.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.6
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• pp.625-632
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• 1992

This paper presents a new dc-motor position control approached by Variable Structure System. In order to eliminate a steady-state position error, we propose a switching function composed of position error, velocity, and current ripple. The switching function has an advantage compared to other ones. To determine the control signal voltage, we use a fuzzy logic method. The simulation results show expected performances.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.4
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• pp.168-178
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• 2002

The CNC machine toots has two kinds of fault. One is the fault due to degraded parts and the other is the fault due to operation disability. The phenomena of degradation is predictable but the operational fault is unpredictable because it occurred without any warning. The major faults of CNC machine tool are operational faults which are charged over 70%. This paper describes the model of remote service and the intelligent fault diagnosis system to diagnosis operational faults of CNC machine tools. To generalize fault diagnosis, two diagnosis models such as SF(Switching Function) and SSF(Step Switching Function) are proposed. The SF is static model and SSF is dynamic model for expression of fault. The SF and SSF model can be generated using SFG(Switching Function Generator) which is developed in this research. The three major operational faults such as emergency stop error, cycle start disability and machine ready disability are applied to experiment of fault modeling. To remote service of faults fur CNC machine tool, the web server and client system based internet are proposed as the suitable environment. The developed two technologies are implemented with the internal function of open architecture controller. The implemental results for two technologies are presented to validate the proposed scheme.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.92-97
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• 2001

The major faults of CNC machine tool is operational error which is charge over 70%. This paper describes model of remote service and fault diagnosis for CNC machine tool with open architecture controller. For intelligent fault diagnosis, new model is proposed. In this paper, the three major operational faults, emergency stop error, cycle start disable and machine ready disable, are defined. Two diagnostic models based on the ladder diagram, switching function model, step switching function model, are proposed. For internet based remote service, suitable environment is proposed and implemented with web server and client.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.195-198
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• 2008

Recently, with the growth of photovoltaic system, many researchers and companies have concerned about the multi-level inverter which has an efficiency of boosting voltage. This paper implements a multi-level switching function based on the FPGA. It is efficient to implement the switching function based on the FPGA as a program able logic device. In order to implementation the switching function, this paper synchronized with the microprocessor through the clock and synchronous signal from the microprocessor.

• ETRI Journal
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• v.9 no.4
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• pp.26-35
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• 1987

Switching system can be regarded as the key node of Integrated Services Digital Networks(ISDN) because it plays the Important role in realization of ISDN. As ISDN is evolved from the telephony Integrated Digital Network(IDN), the switching system for ISDN will be evolved from the function and structure of telephony digital switching system. At near future, ISDN switching system is expected to implement the integrated access and transparent switching functions for both voice and data. As final goals of switching system, advanced switching methods for information having various traffic characteristics such as voice, data, text and image should be considered. This paper considered. This paper will show some of the fundamental design challenges and architectural trends in ISDN switching system.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.315-318
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• 2003

This paper proposes a switching control method applicable to any affine, 2nd order nonlinear system with single input. The key contribution is to develop a control design method which uses a piecewise continuous Lyapunov function non-increasing at every discontinuous point. The proposed design method requires no restrictions except full state availability. To obtain a non-increasing, piecewise continuous Lyapunov function, we change the sign of off-diagonal term s of the positive definite matrix composing the former Lyapunov function according to the sign of the Inter-connection term. And we use the solution of inequalities which guarantee each Lyapunov function is non-increasing at any discontinuous point.

• 전기의세계
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• v.28 no.6
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• pp.61-77
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• 1979

This paper is concerned with minimization process of the binary logic function. This paper describes an algorithm called the SIMPLE TABLE METHOD that well suited to minimization a switching function of any number of variables. For the Simple Table construction, a theorem based upon the numerical properties of the logic function is derived from the relationships governing minterms of the given function. Finally the minimal sum of products can be obtained in terms of the Direct Method or the Indirect Method from the table and table characteristics derived from the Simple Table. The properties and table characteristics used in this paper are described. All the minterms of a switching function are manipulated only by decimal numbers, not binary numbers. Some examples are used as a vehicle to guide the readers who are familiar with the Karnaugh map and Quine-McCluskey tabular method to this New method. These examples not only treat how to handle Don't Care miterms but also show the multiple output functions.

• International Journal of Control, Automation, and Systems
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• v.4 no.4
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• pp.428-437
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• 2006

Many physical systems are hybrid in the sense that they have continuous behaviors and discrete phenomena. In control system with multiple models, switching strategy and stability of the closed-loop system under switching are very important issues. In this paper, a novel adaptive control scheme based on multiple parameter models is proposed to cope with a change in Parameters. Switching strategy guarantees the non-increase in the global control Lyapunov function if the estimation of Lyapunov function value converges. Least-square estimation is used to find the estimated value of the Lyapunov function. Switching and adaptation law guarantees the stability of closed-loop system in the sense of Lyapunov. Simulation results on anti-lock brake system are shown to verify the effectiveness of the proposed controller in view of a large change in system parameters.