• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.2
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• pp.29-34
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• 1983

A simulated inductance, with a phase parameter control circuit containing only two resistors and one operational amplifier, is realized as a two terminal network. Analytical results of the proposed circuit avow that we can realize a simulated inductance for constant inductance value, and experimental results confirm the theoretical predictions. Error of maximum 4%, between theoretical and experimental results of equivalent inductance, has been observed over a wide range of frequencies up to about 100 KHz.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1087-1091
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• 2007

Exact impedance modeling of the electrode/electrolyte interface is important in bio-signal sensing electrode development. Therefore, the investigation of the equivalent circuit models for the interface has been pursued for a long time by several researchers. Previous circuit models fit the experimental results in limited conditions such as frequency range, type of electrode, or electrolyte. This paper describes a new electrical circuit model and its capability of fitting the experimental results. The proposed model consists of three resistors and two constant phase elements. Electrochemical impedance spectroscopy was used to characterize the interface for Au, Pt, and stainless steel electrode in 0.9% NaCl solution. Both the proposed model and the previous model were applied to fit the measured impedance results for comparison. The proposed model fits the experimental data more accurately than other models especially at the low frequency range, and it enables us to predict the impedance at very low frequency range, including DC, using the proposed model.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.1077-1080
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• 1998

In this paper, a simple low-power current-mode CMOS wotage reference circuit is proposed. The reference circuit of enhancement-mode MOS transistors and resistors. Temperature compensation is made by adding a current component proportional to a thermal voltage to a current component proportional to a threshold voltage. The designed circuit has been simulated using a $0.65\mu\textrm{m}$ n-well CMOS process parameters. The simulation results show that the reference circuit has a temperature coefficient less than $7.8ppm/^{\circ}C$ and a power-supply(VDD) coefficient less than 0.079%/V for a temperature range from $-30^{\circ}C$ to $130^{\circ}C$ and a VDD range from 4.0V to 12V. The power consumption is 105㎼ for VDD=5V and $T=30^{\circ}C.$ The proposed reference circuit can be designed to generate a wide range of reference voltages owing to its current-mode operation.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.193-196
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• 2003

This paper describes a micro DC-DC converter using LTCC(Low Temperature Cofired Ceramics) technology. We have designed a inductor, an embedded structure to maximize the effect of miniaturizing, and applied the Neumann's formula to calculate inductance. Also, we have implemented a micro DC-DC conveter of which whole volume is $13{\times}18{\times}0.13[mm^3]$ by embeding other passive components such as resistors and capacitors.

• Journal of electromagnetic engineering and science
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• v.7 no.1
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• pp.42-46
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• 2007

This paper presents a linear amplitude equalizer developed to secure the linearity of the slope of the amplitude over the frequency band ranging $2\sim18\;GHz$. The circuit model is featured by the resistor placed between each pair of a transmission-line and a stub. The design includes finding the values of resistors and stubs to have the optimal linear slope and return loss performances. The measured data show the acceptable performances of the slope variation and return loss over $2\sim18\;GHz$.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.6
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• pp.1010-1016
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• 2004

In this paper, a scheme for estimating the parameters of solar cells and a NN-based emulator for predicting the maximum power point are presented. The diode model with series and shunt resistors is used to estimate parameters highly affecting its V-I characteristic curve and both a real-coded genetic algorithm and the model adjustment technique are employed. For implementing the emulator, a multi-layered neural network incorporating with the BP algorithm is used. A set of simulation works using both field data and generated data are carried out to demonstrate the effectiveness of the proposed method.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.3
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• pp.113-121
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• 1993

The pressure distribution between body and seat surface has been considered as one of the most important factors which affect seation comfort. The pattern of body pressure distribution has been an index of measuring comfort of an automobile seat. There has been numerous studies that measured the body pressure distribution. But, studies have many problems(pressure distortion, resolution, reliability, portability, usability, and shape fitness) in measuring the body pressure distribution. In this study, the new body pressure distribution measuring equipment has been developed by using the thin, flat, and polymer-film devices known as Force Sensing Resistors(FSRs) in order to solve those problems.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.243-245
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• 2009

In this paper, wireless remote controller for welderss are implemented using RF communication. It can be used for general welding power sources. Sometimes, wireless remote controllers for welders are needed because welding torches are far away from welding sources in the case of big ship-building or big tank constructions. In order to use the wireless remote controllers, digital cpu-based welding systems are essential for digital interfaces. But, in this paper, using digital resistors makes wireless remote controllers be easily applied to digital or analog welders. To demonstrate the practical significance of our results, some experimental results are presented.

• Journal of Power Electronics
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• v.18 no.4
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• pp.997-1006
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• 2018

This paper proposes a transformerless photovoltaic (PV) power converter system based on the DC/AC boost inverter, which can solve the leakage current and second-order ripple power issues in single-phase grid-connected PV inverters. In the proposed topology, the leakage current can be decreased remarkably since most of the common-mode currents flow through the output capacitor, by-passing parasitic capacitors, and grounding resistors. In addition, the inherent ripple power component in the single-phase grid inverter can be suppressed without adding any extra components. Therefore, bulky electrolytic capacitors can be replaced by small film capacitors. The effectiveness of the proposed topology has been verified by simulation and experimental results for a 1-kW PV PCS.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1012-1015
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• 1992

A gate-turn-off thyristor (GTO) that has a fuction of self-commutation is a device that can be turned on like a thyristor with a single pulse of gate current and turned-off by injecting a negative gate current pulse. GTOs have been in existence almost from the beginning of thyristor era, recently are these devices being developed with large power-handling capabilities and improved performance, and they are gaining popularity In conversion equipment. In this paper, the effects of internal parameters of GTO model using a circuit containing two transistors and three resistors the switching operation and the turn-off snubber characteristics is investigated using SPICE program.