• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.2
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• pp.97-104
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• 2017

In this paper, we designed and fabricated the multi band Transceiver Assembly(TCA) for the Multi Channel Synthetic Aperture Radar(MCSAR) containing C-band, X-band, Ku-band and we researched to verify electrical performance of TCA. The transceiver consists of transmitters, receivers, signal selection modules for each band, and stability oscillator, frequency synthesizer, controller, power distributor. The transceiver has a receive path selection and bandwidth selection functions in accordance with the operating mode. And the transceiver can transmit and receive all three bands simultaneously, each band has a bandwidth of up to 300 MHz. Final transmission output of transceiver for each band is over 20 dBm to be suitable for driving the T/R module. Receiver bandwidth is selected according to the required function and receiver gain has approximately C-band 52 dB, X-band 50 dB, Ku-band 60 dB, the maximum noise figure of Ku-band V polarization is 4.28 dB in the whole band H, V polarization. As a result of the electrical performance test, a multi-band TCA is satisfied the property requirements of the MCSAR.

• Annual Conference on Human and Language Technology
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• 1997.10a
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• pp.261-268
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• 1997

일본어에서 조동사 "-reru, -rareru"는 '피동', '가능', '자발', '존경' 등의 의미로 두루 쓰이고 있다. 일한 번역에서 이들은 여러 가지 대역어로 나타나며 일정한 규칙이나 패턴을 취하지 않으므로, 기계 번역시 조동사 "-reru, -rareru"는 그 처리가 쉽지 않다. 더구나, 조동사 "-reru, -rareru"는 일본어에서 높은 빈도로 등장하여 무시하기 어렵고 의미별 분포가 고루 퍼져 있어, 대표적 대역어인 "-아/어/여 지다. -되다" 등으로만 대응시킬 경우의 번역 에러는 의외로 치명적이다. 따라서, "-reru, -rareru"의 번역을 고려한 특수 처리를 행할 필요가 있다. 먼저, 본 논문에서는 조동사 "-reru, -rareru"가 포함된 아사히 신문 가사의 5,800여 문장을 대상으로 각각의 의미에 대한 분포 및 한국어 대역어의 빈도를 조사하였다. 대역어는 크게 8종류의 형태로 나누었으며 각 동사별로 "-reru, -rareru"와 결합된 경우의 의미 출현 빈도를 참고하여 대응 가능한 대역어 형태들을 미리 결정하였다. 그리고, 대역어가 여러 개 존재하는 경우는 패턴 매칭을 통하여 적절한 대역어를 선택할 수 있도록 하였다. 그 결과, 약 87%의 "-reru, -rareru"가 적절한 대역어로 번역되어, 본 논문에서 제시한 의미 출현 빈도에 기반한 각 동사별 대역어 형태 결정 방법이 "-reru, -rareru"의 다의성 해소에 유효하다고 판단된다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.9
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• pp.38-48
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• 2000

This paper presents the photonic bandgap structure that has a defect mode within a broad stopband. In order to create a broad stopband, we eliminated one of periodic stopbands of PBG structure by using a quarter-wavelength transformer and cascaded another PBG structure having a center frequency corresponding to the eliminated stopband. We have demonstrated that it is a simple and effective method that can solve an overlapping problem of periodic stopband in two cascaded PBG structures.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1053-1058
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• 2021

This paper presents the multi-band mixer which converts a X-, K- and Ka-band adaptively by adjusting the gate-bias voltage of an active device. The proposed mixer presented a conversion loss of -10 dB at -0.8 V gate-bias voltage for X-band, a conversion loss of -9 dB at -0.3 V gate-bias voltage for K-band and for Ka-band, a conversion loss of -7 dB at -0.2 V gate-bias voltage under the LO power of +6.0 dBm. The 1dB compression point (P1dB) is +0.5 dBm for all band.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.1107-1110
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• 2000

망 복구에 있어서 주요한 과제는 복구의 대상으로 하고 있는 작업 경로(working path)에 대한 복구경로(restoration path) 흑은 대체 경로(backup path)를 설정하는 것이다. 대체 경로를 설정할 때 작업경로의 대역을 보장할 수 있는 대체 경로를 설정해야 한다. 따라서 이 과제는 대역의 보장을 고려하여 경로를 설정하는 QoS 라우팅의 해결책이 요구된다. 본 논문에서는 동일 링크의 작업 경로가 아닐 경우 대체 경로의 대역을 공유함으로써 최대한 대역의 소비를 피하면서, 작업 경로의 대역을 보장하는 대체 경로를 설정하는 disjoint 경로를 계산하는 알고리즘을 제시하고 시뮬레이션을 통해서 대체 경로로 인한 대역의 소비(bandwidth consumption) 효과를 분석하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.131-134
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• 2006

가입자 망은 광대역화, 서비스 융복합화로 가입자 망의 비대칭적인 트래픽이 심화되어 QoS에 문제점을 안겨주고 있다. 이더넷망에 가입자망의 비대칭 트래픽을 적용하기 위해 대역제어의 기술이 적용되고 있다. 가입자망에 적용되고 있는 대역제한 방법에는 여러 가지 방법이 있다. 본 논문에서는 대역제한의 여러 가지 방법을 알아보고 실험을 통해 대역제한 방법에 대한 분석을 한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.3
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• pp.376-379
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• 2014

In this paper, we designed more improving a dual-band power amplifier than the transceiver of RFID reader that operates at 910 MHz and 2.45 GHz. A dual-band power amplifier has two circuits. One matching circuit is composed lumped element in the band of 910 MHz. The other matching circuit using distributed element in the high band of 2.45 GHz. So, this dual-band power amplifier works as Band Rejection Filter in the band of 910 MHz but in the high band of 2.45 GHz works as Band Pass Filter. Therefore, this is composed a microstrip transmission line. A power amplifier is showed gains of 8 dB output power at 910 MHz and 1.5 dB output power at 2.45 GHz. If input power is 10 dBm, both of bands output 20 dBm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.772-779
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• 2015

In this paper,a reconfigurable multi-band mobile antenna with switching line for LTE band 13, GSM, K-PCS, WCDMA band. The proposed antenna is planar strip line design and composed of stub shorted to the ground plane and two switching line for proposed band operation. To obtain the optimized parameters, we used the simulator, Using the obtained parameters is fabricated. The numerical and experiment results demonstrated that the proposed antenna satisfied the -6 dB impedance bandwidth requirement while simultaneously covering when the state of sw1 and sw2 on for LTE band 13, the state of sw1 off and sw2 on for GSM, K-PCS, the state of sw1 off and sw2 off for WCDMA. Respectively and characteristics of gain and radiation patterns are determined for a reconfigurable multi-band mobile terminal.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.4
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• pp.362-370
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• 2001

In this paper, we proposed multispectral image compression method using CIP (classified inter-channel prediction) and SVQ (selective vector quantization) in wavelet domain. First, multispectral image is wavelet transformed and classified into one of three classes considering reflection characteristics of the subband with the lowest resolution. Then, for a reference channel which has the highest correlation and the same resolution with other channels, the variable VQ is performed in the classified intra-channel to remove spatial redundancy. For other channels, the CIP is performed to remove spectral redundancy. Finally, the prediction error is reduced by performing SVQ. Experiments are carried out on a multispectral image. The results show that the proposed method reduce the bit rate at higher reconstructed image quality and improve the compression efficiency compared to conventional methods. Index Terms-Multispectral image compression, wavelet transform, classfied inter-channel prediction, selective vetor quantization, subband with lowest resolution.

• Journal of Navigation and Port Research
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• v.32 no.6
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• pp.481-487
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• 2008

Ship's wireless LAN was in the limelight as equipment of ease, cost reduction, various func tion al i ty. In the paper, a dual-bandpass filter for wireless LAN has proposed, which was designed by using dual-mode square loop resonator with square patch in compliance with 2.4 GHz and 5 GHz band of wireless LAN. The dual-bandpass filter could be designed by adjusting sizes of one perturbation element and three of reference elements in compliance with the frequency bands of 2.4 GHz and 5.8 GHz, Furthermore, new dual-bandpass filter was also designed by adjusting stopband of using open stubs in compliance with the frequency bands of 2.4 GHz and 5.2 GHz. The measured results for the fabricated dual-bandpass filters agreed well with the simulated ones, and hence, it was confirmed that the proposed design method is valid.