• Progress in Superconductivity
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• v.1 no.2
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• pp.81-84
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• 2000

A Josephson sampler circuit using high-Tc superconductor (HTS) ramp-edge junctions has been designed, fabricated, and experimentally tested. It consists of five ramp-edge junctions with a stacked groundplane and is based on single-flux-quantum (SFQ) operations. The sampler was used to measure current waveforms at picosecond and microampere resolutions. We are developing a system based on the sampler for measuring the current waveform in a room-temperature sample. And measuring current flowing through wiring in a semiconductor large-scale integrated circuit is a promising application for the HTS sampler system.

• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.287-292
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• 1998

As business looks towards the $21^{\st}$ century, a long-term strategy that focuses on global sourcing will be the vital factor in whether companies win or lose. At the same time, with electronic components, it is important to ensure stable quality and reliability, together with other important parameters. In order to achieve this, creating an effective mechanism of failure analysis and database management for electronic components is essential. The authors introduce the actual mechanism employed by NEC and explain the ideas and insight they have obtained from their experience.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1347-1350
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• 2006

최근 인터넷과 같은 개방된 네트워크의 발달로 데이터의 양이 기하급수적으로 증가하고 있으며 데이터의 단위 크기도 커지고 있다. NEC 시스템에서 이러한 크고 많은 데이터들을 효율적으로 관리하고 컴퓨터의 성능을 최대로 활용하기 위하여 파일 시스템을 설계하고 구현하여 그 성능을 시험하고 분석하였다. 전체 컴퓨터의 성능을 결정하는 요소는 CPU와 메모리, 디스크, 그리고 이들을 연결하는 네트워크 등 여러 가지가 있지만 이러한 각각의 부분적인 시스템 중에서 사용자가 수행할 프로그램 특성에 맞게 설계하여 사용할 수 있는 부분은 파일 시스템이다. 파일 시스템은 전체 시스템의 특성과 사용자의 프로그램 용도를 고려하여 알맞게 설계되면 시스템의 성능을 더 향상시킬 수 있다. 본 논문은 NEC 시스템에서의 파일 시스템을 시스템의 특성과 용도에 맞게 설계하고 테스트하여 그 성능 결과를 분석하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1212-1216
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• 2003

In this study, the ${\pi}/4$ shift QPSK(quadrature phase shift keying) with NEC(nonredundant error correction) on the multipath channel can detect the burst error as well as random error one by using the second and L-th order phase difference. Therefore, the BER(bit error rate) performance in ${\pi}/4$ shift QPSK is more improved than that of the ${\pi}/4$ shift QPSK without NEC structure. Also, this performance become a bit better in Rayleigh fading channel.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.711-712
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• 2008

여러 산업분야에서, 폭발이 발생할 경우 인명이나 장비에 심각한 피해를 입히게 되며, 폭발에 의한 피해를 최대한 줄이기 위하여 대부분의 국가는 나름대로의 법률이나 규칙, 규정 등의 적용을 강제하고 있으며, 그에 따른 인증 절차를 거치도록 하고 있다. 방폭형 전기기기에 대한 국제규격은 IEC와 북미의 NEC가 권위가 있다. 본 연구에서는 방폭형 전기기기에 대한 규격을 분석하기 전단계로 위험지역 분류에 대한 IEC, NEC 규격별 차이를 먼저 비교 분석하였으며, 또한 향후 대형 전동기의 방폭형 시장 확대가 예상되는 '압력'형 전동기에 대해 적용 규격을 분석하고 설계에 반영할 수 있도록 하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.762-765
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• 2000

The changes of carnitine levels including nonesterified-carnitine(NEC), acid-soluble acylcarnitine(ASAC) and total carnitine (TC) were investigated in developing soybean sprouts. The concentrations of carnitines were determined in ungerminated and germinated soybean seeds, and in dissected axis segments and cotyledone of the germinated sprouts. Soybean seeds contain 136 nmol of TC per gram dry weight. the contents of NEC, ASAC, and TC were increased during the germination of soybean seeds. The concentrations of NEC and ASAC were highest in cotyledone and inmeristematic tissues, respectively. These data indicate that developmental differences of carnitine levels do exist in plants, and that in delveoping soybean sprouts the levels of NEC and ASAC are highest in the cotyledone and in the youngest meristem, respectively.

• Bulletin of the Korean Chemical Society
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• v.16 no.4
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• pp.305-309
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• 1995

The enantiomeric separation of several amino acid derivatives by reversed-phase liquid chromatography using two (R)-and (S)-naphthylethylcarbamate-β-cyclodextrin(NEC-β-CD) bonded stationary phases was studied to illustrate the chiral recognition model of the enantiomeric separation. The retention and enantioselectivity of the chiral separations with (R)-and (S)-NEC-β-CD bonded phases were compared with similar separations with the native β-CD stationary phases. Especially, the enantioselectivity and elution orders between the derivatized amino acid enantiomers are carefully examined. These results can be illustrated by the chiral recognition models involving inclusion complexation, π-π interaction, and/or hydrophobic interaction. Inclusion complexation and hydrophobic interaction of the naphthyl group of the NEC moiety seem to be major chiral recognition components in the enantiomeric separation of 2,4-dinitrophenyl amino acids and dabsyl amino acids on (R)-and (S)-NEC-β-CD columns. For dansyl amino acids, only the inclusion complexation is the dominant factor. Three different chiral recognition models containing π-π interaction, inclusion complexation and hydrogen bonding were proposed for the separation of the 3,5-dinitrobenzoyl amino acid enantiomers, depending on the size and shape of amino acids.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.4
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• pp.429-438
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• 1986

In this paper we have designed and implemented a real-time, full-duplex SBC (sub-band coding) codec at 16kbps using a high speed digital signal processor, NEC 7720. The SBC codec employs a QMF(quadrature mirror filter) filter bank based on the tree structures of two-band analysis-synthesis pairs to partition speech signal into 4 octabe bands. Computer simulation has been done to investigate the effect of fixed-point computation of the NEC 7720. Three different performance measures, the conventional signal-to-noise ratio, the informal listening test, and an LPC(linear predictive coding)distance measure, have been used in this simulation. The necessary parameters have been optimized through the simulation. The developed hardware and software have been tested in real-time operation using a hardware emulator.

• Proceedings of the KIEE Conference
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• 1984.07a
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• pp.103-106
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• 1984

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2001.05a
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• pp.99-108
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• 2001