• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.393-395
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• 2006

We investigated the operational characteristics of the hybrid-type superconducting fault current limiter (SFCL) according to the serial and parallel connections of secondary circuits. The hybrid-type SFCL consists of a transformer, which has a primary winding and several secondary windings with $YBa_2Cu_3O_7$ films connected in series and parallel. In order to increase the capacity of the SFCL, the serial connection between each current limiting unit is necessary. The hybrid-type SFCL with the serial connection in secondary circuits could show superior characteristics than those of the parallel connections in the current limiting and quench time. The resistances generated in the superconducting units were also lowered at the parallel connections. We confirmed that the parallel connection reduced the power burden of each superconducting unit under the same conditions because of the simultaneous quenching between superconducting units.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.8
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• pp.18-25
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• 2008

The paper presents a modeling of the grid-connected wind turbine generation system on MATLAB/Simulink and aims to perform simulations for analysis of the system's characteristics. It performs a pitch regulation for control of the wind generator's output with respect to wind speed variation, and presents a relationship between interconnecting transformer's connections and fault current by reviewing the variations of fault current according to transformer connections in a grid-connected wind power generation system. It also investigates the effect of grounding methods of the interconnecting transformer's neutral point on fault current variations. The simulation results show the differences of fault currents, voltages and generator's characteristics for a line-to-ground fault according to interconnecting transformer's four different connections, and the differences of fault currents of the system according to grounding methods of the transformer neutral point. Therefore, the case studies demonstrate the effectiveness of the proposed simulation model on Simulink.

• Journal of Electrical Engineering and information Science
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• v.2 no.3
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• pp.22-28
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• 1997

In this paper, we propose an efficient multicast addressing scheme for he self-routing multistage networks. Using only N-bit routing header an the simple hardware logic, the new scheme can efficiently provides all point-to-multipoint connections in single pass through the multistage copy networks. We also designed a hardware logic of switching element to implementation of multicasting in ATM switches are performed.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.33 no.2
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• pp.47-55
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• 1984

This paper is concerned with a computer-aided state assignment, that is, coding race-free internal states of asynchronous sequential circuits, and a method for minimizing the combinational network of asynchronous sequential circuits. The FORTRAN version of the peoposed algorithm results in race-free state assignments and reduction of the number of connections and gates with near minimal hardware cost. Some examples are designed by the proposed computer program to illustrate the algorithm in this paper. Finally, results are compared with those of the other methods.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.323-327
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• 2008

We investigated the quench characteristics of a flux-lock type superconducting fault current limiter (SFCL) depending on the methods of the serial and parallel connections between the superconducting elements. The flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil through an iron core, and the secondary coil is connected to the superconducting elements in series and parallel. In this paper, the analyses of voltage, current, and resistance of the superconducting elements connected in serial and parallel were performed to increase the power capacity of the flux-lock type SFCL. A part of the superconducting elements was not quenched in $2{\times}2$ serial connection between the elements and then the power burden of the quenched elements was increased. However the elements with $2{\times}2$ parallel connection was all quenched. This means that the power burden of each superconducting element can be reduced under the same conditions. We found that $2{\times}2$ parallel connection was more profitable for the current limiting effects and the increase of the power capacity.

• Smart Structures and Systems
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• v.13 no.4
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• pp.567-585
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• 2014

The piezoelectric transverse $d_{15}$ shear sensing mechanism is firstly assessed experimentally for a cantilever smart sandwich plate made of a piezoceramic axially poled patched core and glass fiber reinforced polymer composite faces. Different electrical connections are tested for the assessment of the sensor performance under a varying amplitude harmonic (at 24 Hz) force. Also, the dynamic response of the smart sandwich composite structure is monitored using different acquisition devices. The obtained experimentally sensed voltages are compared to those resulting from the benchmark three-dimensional piezoelectric coupled finite element simulations using a commercial code where realistic features, like equipotential conditions on the patches' electrodes and mechanical updating of the clamp, are considered. Numerically, it is found that the stiffness of the clamp, which is much softer than the ideal one, has an enormous influence on the sensed voltage of its adjacent patch; therefore, sensing with the patch on the free side would be more advantageous for a cantilever configuration. Apart from confirming the latter result, the plate benchmark experimental assessment showed that the parallel connection of its two oppositely poled patches has a moderate performance but better than the clamp side patch acting as an individual sensor.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.356-361
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• 1998

Neural Networks, modeled succinctly from the real nervous system of a living body, can be categorized into two folds; artificial neural network(ANN) and biological neural network(BNN). While the former has been developed to solve practical problems using function approximation capability, pattern classification) clustering algorithm, etc, the latter has been focused on verifying the information processing capability to which brain research gives an impetus, by mimicking real biological systems. However, BNN suffers Iron severe nonlinearities dealt with. A bridge between two neural networks is chaotic neural network(CNN), which simply delineate the real nor-vous system and comprises almost all the ANN structures by selecting parameters. Main research theme of this area is to develop an explanation tool to clarify the information processing mechanism in biological systems and its extension to engineering applications. The CNN has a Gaussian-shaped refractory function with hysteresis effect and the chaotic responses of it have been observed fur a wide range of parameter space. Through the examination of the coupling effects of excitatory and inhibitory connections, the secrets of information processing and memory structure will appear.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.172-175
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• 2000

The crimping connection is a permanent connection that maintains mechanical and electrical property for a long time by crimping two conductors. In this paper, we have done a basic study to decide normal or abnormal condition depending on crimping. Using PZT piezo-sensor, we have analyzed crimping waveforms according to the crimping height. And hence the normal or abnormal condition of crimping connections in real time could be decided by comparison of crimping waveforms in the cases of normal crimping, over crimping, under crimping and core omitting.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.2
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• pp.216-221
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• 2004

This paper describes an optimal synthesis method of binary neural network for pattern recognition. Our objective is to minimize the number of connections and the number of neurons in hidden layer by using a Newly Expanded and Truncated Learning Algorithm (NETLA) for the multilayered neural networks. The synthesis method in NETLA uses the Expanded Sum of Product (ESP) of the boolean expressions and is based on the multilayer perceptron. It has an ability to optimize a given binary neural network in the binary space without any iterative learning as the conventional Error Back Propagation (EBP) algorithm. Furthermore, NETLA can reduce the number of the required neurons in hidden layer and the number of connections. Therefore, this learning algorithm can speed up training for the pattern recognition problems. The superiority of NETLA to other learning algorithms is demonstrated by an practical application to the approximation problem of a circular region.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.488-490
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• 2003

As aluminum becomes more widely used in power distribution systems, so the corrosion caused by bimetallic contacts of aluminum and copper becomes more serious problem. In particular, the poor contact of the commonly used compression type bimetal connections may bring about the disastrous interruption of the power supply resulted from the increased corrosion within the joints, which is accelerated by the permeation of water and electrolyte into the interface. In this paper, the corrosion characteristics of aluminum and copper are investigated to improve the reliability of Al-Cu connectons.