• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.211-214
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• 2002

In this paper, we present a simple method for characterizing a rectangular waveguide to circular waveguide transition Three standard loads consisting of a short circuit, an offset short circuit 1, and an offset short circuit 2 are sequentially connected to the circular waveguide port and the reflection coefficient at port 1 Is measured for each case. From known reflection coefficients, of standard loads and measured reflection coefficients, the scattering matrix of the transition Is obtained. The proposed method Is verified by the numerical experiment using a commercial software HFSS and by measurments of a actual rectangular-to-circular waveguide transition.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.1005-1008
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• 2000

This paper presents a simple method to estimate short-circuit power dissipation and propagation delay for static CMOS logic circuits. Short-circuit current expression is derived by accurately interpolating peak points of actual current curves which is influenced by the gate-to-drain coupling capacitance. The macro model and its expressions estimating the delay of CMOS circuits, which is based on the current modeling expression, are also proposed after investigating the voltage waveforms at transistor output modes. It is shown through simulations that the proposed technique yields better accuracy than previous methods when signal transition time and/or load capacitance decreases, which is a characteristic of the present technological evolution.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2094-2096
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• 2005

In this paper, we studied the cross section analysis based on the short circuit conditions of the low voltage bare wires. The copper wires prepared for the experiment were 1.2mm 1.6mm and 2.0mm in diameter. Through the cross section analysis(CSA), it was confirmed that the dendrite structure grew at the angle of about $40^{\circ}$ or $60^{\circ}$ when the fusing current was applied to the wires. The larger the fusing current is, the more decreased the growth angle of the dendrite structure is. It was confirmed that the dendrite structure was arranged like the columnar structure. In this paper, the characteristics analysis of short circuit was carried out in the range of transient duration.

• Journal of Welding and Joining
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• v.9 no.2
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• pp.20-28
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• 1991

The main subject of this study is the construction of an automatic welding system that has the capability to trace the weld seam in GMA welding of lap joints. The system was composed of a vision sensor, moving torch, and personal computer(IBM-PC). In the developed vision sensor, an image was captured by the frame grabber at the time of short circuit during welding. The threshold method was adopted for determining the structured light and the central difference method for detecting the weld joint. And the seam tracing of the torch was performed by using the data regeneration algorithm. In this system using the image at the time of short circuit, weld seam tracking was performed without any relations to arc light and spatters.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.4
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• pp.523-531
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• 2019

This paper deals with a wound-field synchronous machines(WFSM), with an electromagnet on its salient rotor, as an alternative to a permanent magnet in the rotor. We then examine the power performance characteristics, loss characteristics, V-curves and large short-circuit ratios for a large-scale synchronous generator, considering the leading and lagging operations, based on the finite-element method. We predict the performance of a 100MVA-class generator based on the operating range for a constant short-circuit ratio. At the last, We compared with the electromagnetic characteristics of three model according to number of slots.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.130-134
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• 2022

An anti-reflective coating is used to improve the performance of the solar cell. The anti-reflective coating changes the value of the short-circuit current about the thickness. However, the current-voltage characteristics about the anti-reflective coating are difficult to calculate without simulation tool. In this paper, a modeling technique to determine the short-circuit current value and the current-voltage characteristics in accordance with the thickness is proposed. In addition, artificial neural network is used to predict the short-circuit current with the dependence of temperature and thickness. Simulation results incorporating the artificial neural network model are obtained using MATLAB/Simulink and show the current-voltage characteristic according to the thickness of the anti-reflective coating.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.6
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• pp.658-663
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• 2015

In the previous work, we have proposed an integrate-and-fire neuron circuit and synaptic device based on the floating body MOSFET [1-3]. Integrate-and-Fire(I&F) neuron circuit emulates the biological neuron characteristics such as integration, threshold triggering, output generation, refractory period using floating body MOSFET. The synaptic device has short-term and long-term memory in a single silicon device. In this paper, we connect the neuron circuit and the synaptic device using current mirror circuit for summation of post synaptic pulses. We emulate spike-timing-dependent-plasticity (STDP) characteristics of the synapse using feedback voltage without controller or clock. Using memory device in the logic circuit, we can emulate biological synapse and neuron with a small number of devices.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.876-880
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• 2013

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The principal factor of the fire is electric arc or spark accompanied with such electric faults. Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB), that is, Residual Current Protective Devices (RCDs) used on low voltage distribution lines cut off earth leakage and overload, but the RCD can not cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied in low voltage distribution panel are prescribed to rated breaking time about 30[ms] (KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To improve such problems, this paper studies on an arc fault circuit interrupter (AFCI) using the distorted voltage wave in electric arc faults. The proposed voltage sensing type AFCI is an electrical fire prevention apparatus of new conception that operates a circuit breaker with sensing the instantaneous voltage drop of line voltage at electrical faults occurrence. The proposed AFCI is composed of control circuit topology using some semiconductor switching devices. Some experimental tests of the proposed AFCI confirm practicality and the validity of the analytical results.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.6
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• pp.284-292
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• 2005

Because all of the short-circuit testing laboratories have the limitation of test facilities, the synthetic making test methods have been used to estimate the short-circuit making performance of the ultra high-voltage circuit breaker as the alternative to direct test methods. So, KERI(Korea Eelctrotechnology Research institute) has completed the construction of the synthetic making test facilities using the low capacity step-up transformer method which fulfill the requirements specified in newly revised IEC 62271-100 Edition 1.1(2003) and have the testing capability up to 550kV, 63kA full-pole circuit breaker. The test facilities using the low capacity step-up transformer method presented in this paper are made up of the unit equipments such as HCS(High-speed Closing Switch), ITMC(Initial Transient Making Current) circuit and UP TR(low capacity step-up transformer) and have the operating range of 17.6$^{\circ}$ $\~$ 145.1$^{\circ}$ for testing the circuit breaker rated on up to 50kA and 43.1$^{\circ}$ $\~$ 119.6$^{\circ}$ for more than 50kA.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.3
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• pp.365-373
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• 2015

We propose a simple and compact thyristor-based neuron circuit. The thyristor exhibits bi-stable characteristics that can mimic the action potential of the biological neuron, when it is switched between its OFF-state and ON-state with the help of assist circuit. In addition, a method of inter-neuron connection with synaptic devices is proposed, using double current mirror circuit. The circuit utilizes both short-term and long-term plasticity of the synaptic devices by flowing current through them and transferring it to the post-synaptic neuron. The double current mirror circuit is capable of shielding the pre-synaptic neuron from the post synaptic-neuron while transferring the signal through it, maintaining the synaptic conductance unaffected by the change in the input voltage of the post-synaptic neuron.