• Journal of Sensor Science and Technology
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• v.5 no.5
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• pp.85-95
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• 1996

Based on the transmission of coupled gap solitons in nonlinear periodic media, we present an all-optical switching scheme which has a novel architecture and principle. The proposed switch with an extremely small switching element can be realized on a semiconductor waveguide. We here investigate the switching performance with a GaAs waveguide in order to give criteria for the experimental realization of the all-optical switching phenomena. We also suggest a variation of an index-matching scheme to solve the technical problem such as the input-energy coupling into a periodic waveguide.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2039-2041
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• 1998

In this paper, Operation characteristics of the active clamp(ACL) zero-voltage-switching(ZVS) forward converter(FC) and active clamp hard- switching(HS) forward converter are compared with respect to loss analysis. The losses of semiconductor (including conduction losses and switching losses), transformer(containing the core loss and copper loss) and parasitic element of passive element (capacitor, inductor) are measured and compared for each type. For an experiment we have built 50W ACL ZVS-FC and ACL HS-FC, in which the switching frequency is 200kHz, and test it. The experimental results show that both types of operation have nearly same characteristics.

• KIEE International Transactions on Power Engineering
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• v.4A no.2
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• pp.79-83
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• 2004

A new small signal stability analysis method for eigenvalue analysis is presented. This method utilizes the Resistive Companion Form (RCF) for the computation of the transition matrix over a specified time interval, which corresponds to a single cycle operation of the system. This method is applicable to any system, with or without switching element. An illustrative example of the method is presented and the eigenvalues are compared with those of the conventional state space method (analog) in order to demonstrate the accuracy of the proposed eigenvalue analysis method. Also, the variations of oscillation modes that are caused by the switching operation can be precisely analyzed using this method.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.100.2-100
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• 2001

In this paper, we presented a switching-based control algorithm for improving the speed of response on temperature control of an extruder. We proposed a switching actuating value method in a temperature control of extruder and showed the effect of H$\infty$ control and PID control. Recently, the memoryless feedback control had proposed, which was not only the real time integration element, but also the memory elements. We examined the application of a switching actuating value method to a memoryless feedback, in a unit barrel temperature control of an extruder.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.220-224
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• 1991

Uninterruptible Power Supply(UPS) Systems are widely used in a varietyof fields as highly reliable power sources. This paper describes the operation and performance of an UPS using sinusoidal Pulse Width Modulation (PWM)techniques. A newly developed UPS adopted switching element -power TR, power MOSFET, IGBT- is introduced. Experimental results showed that sinusoidal PWM techniques have good features for UPS systems.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1534-1544
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• 2002

The TDCSA(Time Delay Control with Switching Action) method, which consists of Time Delay Control(TDC) and a switching action of sliding mode control(SMC), has been proposed as a promising technique in the robust control area, where the plant has unknown dynamics with parameter variations and substantial disturbances are preset. When TDCSA is applied to the plant with saturation nonlinearity, however, the so-called windup phenomena are observed to arise, causing excessive overshoot and instability. The integral element of TDCSA and the saturation element of a plant cause the windup phenomena. There are two integral effects in TDCSA. One is the integral effect occurred by time delay estimation of TDC. Other is the integral term of an integral sliding surface. In order to solve this problem, we have proposed an anti-windup scheme method for TDCSA. The stability of the overall system has been proved for a class of nonlinear system. Experiment results show that the proposed method overcomes the windup problem of the TDCSA.

• Journal of KIISE:Information Networking
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• v.28 no.4
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• pp.657-664
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• 2001

In our predecessor paper(Part I)[13], we introduced a graph that represents the crosstalk relationship among multicast connections in the photonic Banyan-type switching network, and found the upper bound on the degree of it. In this paper(Part II), we consider the number of routing rounds(i.e., scheduling length) required for SE(switching element)-disjoint multicasting in photonic Banyan-type switching networks. Unfortunately, the problem to find an optimal scheduling length is NP-complete thus, we propose an approximation algorithm that gives its scheduling length is always within double of the upper bound on the optimal length. We also study the scheduling length on the Iink-disjoint(i.e., nonblocking) multicasting. Various nonblocking Banyan-type multicasting networks are found under the scheduling lengths.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.4
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• pp.361-367
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• 2014

This paper is related to a new solar power conditioner for a built-in step-up chopper function. In the first step-up chopper proposed solar PV power conditioner for mutually connected in series with the input voltage of the bypass diodes are respectively connected to the positive terminal should install the mutual boosting chopper diode connected in series with the boost chopper switching element between the two power supply and at the same time the first and the second was connected to a second diode and a resonance inductor and a snubber capacitor in series with each other. And the common connection point between the bypass diode and the step-up chopper and the step-up chopper diode common connection point of the switching elements of the input voltage was set to the boost inductor for storing energy. In addition, between the step-up chopper and the step-up chopper diode and a switching element of a joint connection point of the first auxiliary diode and the second common connection point of the auxiliary diode was provided, the resonance capacitor. Between the step-up chopper and the step-up chopper diode and a switching element of a joint connection point and the common connection point of the resonance inductor snubber capacitor and connecting the third secondary diode, between two power supply lines is characterized by configuring the DC link capacitor bus lines in parallel. Therefore, it is possible to suppress the switching loss through, DC link bus lines, as well as there could seek miniaturization and weight reduction of the power conditioner itself by using a common capacitor of the non-polar non-polar electrolytic capacitor having a capacitor, the service life of the circuit can be extended and it is possible to greatly reduce the loss can be greatly improve the reliability of the product and the operation of the product itself.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.4
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• pp.399-404
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• 2012

In this paper, a stator-separated axial flux-switching hybrid excitation synchronous machine (SSAFHESM) is presented, of which the structure and operational principle are introduced. The magnetic field distribution under different excited currents is analyzed, and some characteristics including flux-linkage, EMF and field control ability are studied by finite element analysis (FEA). Tests are carried out on a 12/10-pole prototype machine to validate the analysis results, and an excellent agreement is obtained.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.310-312
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• 1989

From the viewpoint of an effective energy use, many method for reactive power compensation has been developed. Among of the reactive power compensation, this paper describes the relation of operation interpretation, filter, hysteresis width and switching time of current controlled PWM converter which has excellent reactive power compensation. This current controlled PWM convertor is excellent the view of reactive power compensation by current control method using hysteresis comparator method, but is required element of high response characteristics. Therefore this paper offers the series of data for system considering switching characteristics of switching element.