• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2000.11a
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• pp.121-126
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• 2000

국내 원자력발전은 전체 전력공급의 40%이상을 차지하고 있으면서도 그 특성상 기저부하용으로만 사용되고 있다. 그러나 전기에너지의 효율적인 이용과 다양한 전력수요에 능동적으로 대처할 수 있도록 원전의 부하추종운전 능력이 더욱 중요하게 인식되고 있는 상황이다. G7과제의 하나인 차세대원자로(Korean Next Generation Reactor, KNGR)는 기본적인 요건으로 부하추종운전 능력을 갖도록 개발되고 있다. 여기에서는 기존에 개발된 부하추종운전 제어논리를 변경된 부하추종운전 기본요건에 맞도록 하고, 구동 제어군 특성의 극대화 및 온도불감대 출력분포 제어논리 등을 개선시킴으로써 주기초 및 주기중 뿐만아니라 90% 주기말에서도 ASI(Axial Shape Index)가 만족스럽게 제어됨을 확인하였다.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.545-548
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• 2012

1차 에너지 소비량은 계속 증가 되고 있는데 화석연료의 고갈과 기후문제 등으로 소비량을 줄이기 위해 원자력발전과 신재생에너지인 풍력 및 태양광 등이 현재 증가하고 있다. 하지만 증가하는 부하에 대한 대응방안으로 원자력 발전소는 가변제어가 아닌 고정방식이기 때문에 기저부하에 대한 공급을 담당하고 신에너지는 발전량이 일정하지 않기 때문에 또한 피크부하 대응에 불가능하다 그러므로 양수발전소 또는 다른 발전소를 통해 피크부하를 관리하고 있는 상황이다. 하지만 단 몇 시간의 피크부하를 위해 지속적인 발전소를 지을 수 있는 부지도 없고 건설시간도 매우 많이 걸리는 단점이 있다. 본 논문에서는 양수발전 또는 다른 발전소를 대체할 수 있는 전력저장시스템(BESS)의 부하평준화효과에 대한 경제성평가 기법에 대하여 제시한다.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.305-306
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• 2019

본 논문에서는 고전압 커패시터 충전용 3상 LCC 공진형 컨버터를 설계하고 제작하였다. 고전압 커패시터 충전시간과 충전전압간에 선형성을 확보하기 위하여 컨버터는 충전 전 구간에서 정전류원으로 동작하도록 설계되었다. 공진탱크 설계를 위해서 FHA(Fundamental Harmonic Analysis) 기법을 이용하여 첨예도(Q; Quality factor)와 기저 주파수 변동에 따른 입출력 전류이득특성을 도출하였고 이를 바탕으로 28.8kJ/s의 충전속도를 가지며 최대 충전전압은 10kV 인 3상 LCC 공진형 컨버터를 제작하였다. 제작된 컨버터는 10kV, 600kJ 규격의 12mF 고전압 커패시터를 이용한 충전 실험을 통해 설계의 타당성을 확인하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.8
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• pp.610-618
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• 2017

This paper presents a 868/915 MHz CMOS RF transceiver for the ZigBee application. Using a switchless matching network, the off chip switch is removed to achieve the low cost RF transceiver, and by the elimination of the switch's insertion loss we can achieve the benefits for the RF receiver's noise figure and transmitter's power efficiency at the given output power. The receiver is composed of low-noise amplifier, mixer, and baseband analog(BBA) circuit. The transmitter is composed of BBA, mixer, and driver amplifier. And, the integer N type frequency synthesizer is designed. The proposed ZigBee RF full transceiver is implemented on the $0.18{\mu}m$ CMOS technology. Measurement results show that the maximum gain and the noise figure of the receiver are 97.6 dB and 6.8 dB, respectively. The receiver consumes 32 mA in the receiver mode and the transmitter 33 mA in the transmission mode.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.219-226
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• 2000

In this paper, we design and implement a IF(intermediate frequency) module for WLL(wireless local loop) CDMA(code division multiple access) basestation. The implemented IF transceiver is consists of transmitter, receiver and local oscillator. The considered signal bandwidth is 10 MHz and the local carrier frequency is 40 MHz. As test results, the If transmitter output power is -5dBm $\pm3dB$when the baseband input is -10dBm $\pm3dB$, and the IF receiver output power is -10dBm $\pm3dB$when the IF input is -5dBm $\pm3dB$. Also the AGC(automatic gain control) circuit has dynamic range of 9 dB from -7dBm to +2dBm with output power 2dBm. And the group delay characteristic is analyzed by comparing the phase delay from 1 MHz to 5 MHz and the phase distortion is very low. We can conclude that this IF system can be applied to high speed data rate communication system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.3
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• pp.685-690
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• 2013

This paper has proposed a multi-channel and wide gain-range baseband circuit blocks for the IEEE 802.15.4g MR-OFDM SUN systems. The proposed baseband circuit blocks consist of two negative-feedback VGAs, an active-RC 5th-order chebyshev low-pass-filter, and a DC-offset cancellation circuit. The proposed baseband circuit blocks provide 1 dB cut-off frequencies of 100 kHz, 200 kHz, 400 kHz, and 600 kHz respectively, and achieve a wide gain-range of +7 dB~+84 dB with 1 dB step. In addition, a DC-offset cancellation circuit has been adopted to mitigate DC-offset problems in direct-conversion receiver. Simulation results show a maximum input differential voltage of $1.5V_{pp}$ and noise figure of 42 dB and 37.6 dB at 5 kHz and 500 kHz, respectively. The proposed I-and Q-path baseband circuits have been implemented in $0.18-{\mu}m$ CMOS technology and consume 17 mW from a 1.8 V supply voltage.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.4
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• pp.153-159
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• 2011

The MUSIC (MUltiple SIgnal Classification) method estimates the directions of arrival (DOAs) of the signals impinging on a sensor array based on the fact that the noise subspace is orthogonal to the signal subspace. In the conventional MUSIC, an estimate of the basis for the noise subspace is obtained by eigendecomposing the sample matrix, which is computationally expensive. In this paper, we present a simple DOA estimation method which finds an estimate of the signal subspace basis directly from the columns of the sample matrix from which the noise power components are removed. DOA estimates are obtained by searching for minimum points of a cost function which is defined using the estimated signal subspace basis. The minimum points are efficiently found through the Brent method which employs parabolic interpolation. Simulation shows that the simple estimation method virtually has the same performance as the complex conventional method based on the eigendecomposition.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.1
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• pp.24-36
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• 2002

It is important to use frequency resource effectively to support much more users, to maximize the DS-CDMA system performance. In this paper, we use MPSK, QAM, MFSK and PR coder as a baseband modulation method for DS-CDMA system. Increasing user's number, we compare the performance of each system using different baseband modulation method, by expecting BER performance. BPSK has generally good performance, in case of low power operation of terminal 8FSK has excellent performance relatively, PR has excellent performance when high power operation of terminal and also good for situation of excessive user's number. QAM is not suitable for DS-CDMA system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.10
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• pp.2194-2200
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• 2010

In this paper, the power detectors using metamaterials were designed and fabricated for multi-band six-port direct conversion method. The RF short-stubs for power detector were designed by using metamaterials which provide multi-band characteristics. The power detectors with metamaterial RF short-stub were analyzed and fabricated by using lumped and distributed element. The measured results of metamaterial power detectors show the good agreement with the simulation results. The performance of lumped-metamaterial RF short-stub shows the insertion loss below 1 dB and the good frequency response characteristics. Also, the distributed-metamaterial RF short-stub shows the good frequency response characteristics and the insertion loss under that of lumped-metamaterial RF short-stub. The multi-band power detectors with metamaterial RF short-stub detect the input RF signal in the designed dual frequency bands very well.

• Journal of Advanced Navigation Technology
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• v.5 no.2
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• pp.134-140
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• 2001

Ultra Wideband(UWB) system uses wide band signal, which power spectral density likes as a noise floor, so UWB system can be used high speed communication without interfering with other communication system. As this system doesn't use carrier, its structure would be very simple and consume very low power. But conventional UWB system uses Pulse Positioning Modulation(PPM) Method. Therefore it could be to produce discrete power spectrum which decreases system efficiency unintentionally. For eliminating discrete power spectrum and further Euclidean distance, we propose UWB system using Antipodal signal. And we design and simulate antipodal tranceiver using Advanced Design System(ADS).