• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05e
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• pp.89-91
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• 2003

In this paper, using a Langmuir probe Ar gas characteristic of electrodeless fluorescent lamp which used an inductively coupled plasma were investigated. The RF output changed into 5-50W in 13.56MHz. At this time internal plasma voltage of the chamber and probe current were measured while changing in -70V - +70V with a supply voltage by Langmuir probe. If pressure of Ar gas was increased, the electric current tended to decrease. Also, an electric current was increased according to an increase of a RF output.

• Journal of Korea Port Economic Association
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• v.24 no.1
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• pp.85-102
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• 2008

The purpose of this study is to analyze the effects of Logistic Information System on performance by efficiency of internal operation and organizational innovation. The results of this study as follows : The characteristic variable evaluation model that extended from the performance(user's value, perceived usefulness) of Logistic Information System were verified meaningfully. In this study, the efficiency of internal operation and organizational innovation were very important factor, to analyze the effects of Logistic Information System on performance. This study expect that Logistic Information System will achieve their Logistic Information System competitiveness through continuous quality measurement and improvement to increase the performance.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.63-70
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• 2014

A low-N phase-locked loop clock generator with frequency multiplier is proposed to improve phase noise characteristic. Delay-variance voltage converter (DVVC) generates output voltages according to the delay variance of delay stages in voltage controlled oscillator. The output voltages of average circuit with the output voltages of DVVC are applied to the delay stages in VCO to reduce jitter. The HSPICE simulation of the proposed phase-locked loop clock generator with a $0.18{\mu}m$ CMOS process shows an 11.3 ps of peak-to-peak jitter.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.118-123
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• 2015

The study of input and output characteristics in dynamic motion control is important indicator of the performance of mechanical equipment and is the factors to be considered during commissioning and maintenance of machinery or equipment, and project planning. The Analysis on dynamical characteristic of the input/output of the automation solution that used for motion control in machinery, is represented the control performance of device and including controller which connected at automation network by considering period of the frequency as applied load. This paper was constructed the simulator of B & R Powerlink to be widely used for motion control in the machine and showed the dynamic system characteristics by analysing the period.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.423-426
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• 2001

In this paper, an electronic step-down transformer with output voltage stabilization characteristics is presented. The proposed electronic transformer has some advantages and features as follows: 1) It has 40 % weights lighter than that of commercial magnetic transformer, 2) It has output voltage stabilization characteristic with regulated output voltage over input variations, 3) It cab be operated as circuit breaker in the case of emergency, 4) It can be operated with so called soft starting function. Moreover, the electronic transformer may have stand-by power cutoff function and act as distortion compensator. This paper show the circuit diagram and present its features through various PSPICE simulations.

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.120-127
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• 2011

Solar array has the following nonlinear characteristic, such as whose output current increases, output voltage is reduced. For this reason, boost converter with solar array system is always controlled to remain on the maximum power point of the solar array. In this case, we are not focused on the output of the solar array and not consider efficiency of the boost converter, which is assumed reliable. But efficiency of the converter also should be considered, which affects the total efficiency of the overall solar energy system. In this paper, efficiency calculation of the boost converter using power balance method is proposed, which will be used for a powerful reference before hardware realization.

• Journal of information and communication convergence engineering
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• v.16 no.1
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• pp.12-16
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• 2018

In this work, a voltage controlled oscillator (VCO) monolithic microwave integrated circuit (MMIC) was demonstrated for 10-GHz band motion detecting sensors. The VCO MMIC was fabricated using a $2-{\mu}m$ InGap/GaAs HBT process, and the tuning of the oscillation frequency is achieved by changing the internal capacitance in the HBT, instead of using extra varactor diodes. The implemented VCO MMIC has a micro size of $500{\mu}m{\times}500{\mu}m$, and demonstrates the value of inserting the VCO into a single chip transceiver. The experimental results showed that the frequency tuning characteristic was above 30 MHz, with the excellent output flatness characteristic of ${\pm}0.2dBm$ over the tuning bandwidth. And, the VCO MMIC exhibited a phase noise characteristic of -92.64 dBc/Hz and -118.28 dBc/Hz at the 100 kHz and 1 MHz offset frequencies from the carrier, respectively. The measured values were consistent with the design values, and exhibited good performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.238-240
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• 2017

Balun using a coaxial lines i often used in microwave circuits due to easy fabrication, high operating power, and stable operation. However, it is difficult to predict an accurate balun operation characteristic due to the parasitic reactance component to be generated when the coaxial line is connected to the microstrip line existing on the substrate, and the inductance and the capacitance component of the coaxial line itself. In this paper, it is measured the phase characteristics at two output ports of the coaxial line balun which should have opposite phase characteristics. Based on these results, it will examine closely the feasibility of making more improved coaxial line balun.

• Journal of the Korea Society of Computer and Information
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• v.13 no.5
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• pp.263-272
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• 2008

The proposed system can achieve more safety of RFID system with the 2-step authentication procedures for the enhancement about the security of general RFID systems. After it has authenticated RFID tag, additionally, the proposed system extract the characteristic information in the user image for acquisition of the additional authentication information of the user with the camera. In this paper, the system which was proposed more enforce the security of the automatic entrance and exit authentication system with the cognitive characters of RFID tag and the extracted characteristic information of the user image through the camera. The RFID system which use the active tag and reader with 2.4GHz bandwidth can recognize the tag of RFID in the various output manner. Additionally, when the RFID system have errors. the characteristic information of the user image is designed to replace the RFID system as it compare with the similarity of the color, outline and input image information which was recorded to the database previously. In the experimental result, the system can acquire more exact results as compared with the single authentication system when it using RFID tag and the information of color characteristics.

• The KIPS Transactions:PartB
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• v.9B no.2
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• pp.173-180
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• 2002

The virtual cell loss rate was introduced for the training pattern of the neural network in the VOB(Virtual Output Buffer) model. The VOB model shows that the neural network can find the connection admission boundary without the real cell loss rate. But the VOB model tends to overestimate the cell loss rate, so the utilization of network is low. In this paper, we uses the reference curve of the cell loss rate, which contains the information about the cell loss rate at the connection admission boundary. We process the patterns of the virtual cell loss rate using the reference curve, We performed the simulation with two major ATM traffic classes. One is On-Off traffic class that has the traffic characteristic of LAN data and other is Auto-Regressive traffic class that has the traffic characteristic of a video image communication.