• Title/Summary/Keyword: NRD

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WDM Transmission using Inline Dispersion Management of Bi-end Schemes in Optical Transmission Links (광전송 링크에서 bi-end 구조의 inline 분산 제어를 이용한 WDM 전송)

  • Lee, Seong-Real
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.784-786
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    • 2010
  • Implementation possibility of inline dispersion management (DM) using bi-end schemes, which consist of one single mode fiber (SMF) and two dispersion compensating fiber (DCF) placed at front and rear of SMF, respectively, is investigated for compensating total dispersion accumulated in a span of WDM transmission links. It is confirmed that if net residual dispersion (NRD) is decided to be ${\pm}10\;ps/nm$ then bi-end scheme is effective to compensate for WDM channels with wide launching power range.

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System Performance Depending on the Deviation of RDPS in Dispersion Managed Optical Transmission Link with Random Distribution of RDPS (RDPS 분포가 랜덤한 분산 제어 광 링크에서 RDPS 편차에 따른 시스템 성능)

  • Lee, Seong-Real
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.967-970
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    • 2014
  • The compensation characteristics are investigated as a function of the deviation of residual dispersion per span (RDPS) in the optical transmission links with a randomly distributed RDPS and optical phase conjugation (OPC). The simulation results show that the effective launch power are more increased and the effective net residual dispersions (NRDs) are more increased, as the deviation of RDPS is more narrow.

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Identification of Genes for Growth with Oxygen in Escherichia coli by Operon Fusion and Southern Blot Techniques

  • Kim, Il-Man;Lee, Yong-Chan;Won, Jae-Seon;Choe, Mu-Hyeon
    • Journal of Microbiology and Biotechnology
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    • v.13 no.6
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    • pp.976-983
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    • 2003
  • Seven Escherichia coli cells defective with aerobic growth were isolated by the insertion of ${\lambda}placMu53$, a hybrid bacteriophage of ${\lambda}$ and Mu, which created a transcriptional fusion to lacZY. These insertion mutant cells were tested on an XG ($5-bromo-4-chloro-3-indolyl-{\beta}-D-galactopyranoside$) medium for anaerobic expression of lacZ by fusion to a promoter. The chromosomal DNA from these strains were digested by EcoRI, and the EcoRI fragments that contained the fused gene and lacZ sequence were identified by Southern hybridization, using lacZ containing plasmid as a probe. The EcoRI fragment from each strain was cloned and sequenced. The sequence data were compared with the GenBank database. The mutated gene of three strains, CYT4, CYT5, and OS11, was found to be identical, and it was nrdAB that encoded ribonucleoside diphosphate reductase. The gene nrdAB was at min 50.5 on the Escherichia coli linkage map and 2,348,084 on the physical map, and is involved in hemAe-related reduction-oxidation reaction. OS6 and OS14 mutant strains had insertion at min 8.3 and the mutated gene was hemB. The hemB encodes 5-aminolevulinate dehydratase or porphobilinogen synthase. The OS3 mutant had insertion in cydB at min 16.6. The cydAB encodes cytochrome d oxidase. In the case of OS1, the fusion was made with sucA, the E1 component of ${\alpha}-ketoglutarate$ dehydrogenase.

NRZ versus RZ Modulation Format in Lumped Dispersion Managed Systems (집중형 분산 제어 시스템에서 NRZ 변조 형식 대 RZ 변조 형식)

  • Lee, Seong-Real;Cho, Sung-Eon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.2
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    • pp.328-335
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    • 2008
  • The system performance of NRZ format in WDM transmission system with lumped dispersion management(DM) and optical phase conjugator(OPC) is compared with that of RZ format. It is confirmed that eye opening penalty(EOP) of both NRZ and RZ format in WDM transmission system having lumped DM combined with OPC are greatly improved than those in WDM system with only OPC. The optimal net residual dispersion(NRD) in the case of RZ format is decided to so small value that path-averaged dispersion coefficient become almost zero, while that in the case of NRZ format is decided to larger value, for the best improvement of overall WDM channels. It is also confirmed that EOP in the case of RZ format is more improved than that in the case of NRZ format in lumped DM with optimal NRD. This is resulted from that lumped DM combined with OPC suppress the signal distortion due to intrachannel four-wave mixing(IFWM) and intrachannel cross phase modulation(IXPM). Consequently, lumped DM combined with OPC proposed in this paper is effective technique to mitigate intrachannel nonlinearities in WDM transmitting RZ format.

Compensation Characteristics of WDM Signals Depending on Dispersion Coefficient of Dispersion Compensating Fiber and Residual Dispersion Per Span (분산 보상 광섬유의 분산 계수와 중계 구간 당 잉여 분산에 따른 WDM 신호의 보상 특성)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.17 no.1
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    • pp.16-23
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    • 2013
  • The effects of dispersion coefficient of dispersion compensating fiber (DCF) and residual dispersion per span (RDPS) on in the dispersion managed optical links for compensating the distorted 960 Gbps wavelength division multiplexd (WDM) signals due to group velocity dispersion (GVD) and optical nonlinear effects of single mode fiber (SMF) are investigated. It is confirmed that optimal net residual dispersion (NRD), which greatly affects compensating for optical signals, should be induced under the large launch power condition, irrelevant on the considered dispersion coefficient of DCF and RDPS. It is also confirmed that system performances are greatly improved by selecting the very small RDPS and very large dispersion coefficient of DCF.

Performance Improvements through Controling Residual Dispersion Per Span in WDM Transmission Links with Zero Net Residual Dispersion (전체 잉여 분산이 영인 WDM 전송 링크에서 광 중계 거리 당 잉여 분산 제어를 통한 성능 향상)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.13 no.5
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    • pp.656-661
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    • 2009
  • High-quality transmission of $24{\times}40$ Gbps WDM signals obtained through controling residual dispersion per span (RDPS) in optical transmission links with zero net residual dispersion (NRD) of inline dispersion management (DM) of optical transmission links is researched. It is confirmed that RDPS values, which is improving system performance, depends on launch power of WDM channels, but optimal RDPS, which can simultaneously improve WDM signals with relative wide launch power ranges, becomes to be 210~230 ps/nm. Also, it is shown that effective launch power range that making eye opening penalty (EOP) of worst channel to below 1 dB is more increased as RDPS is more increased.

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Q-factor Improvements of WDM Signals using Optical Transmission Link with Dispersion Management and OPC (분산 제어와 OPC를 갖는 광전송 링크를 이용한 WDM 신호의 Q-factor 개선)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.13 no.1
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    • pp.27-33
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    • 2009
  • New optical transmission link techniques improving performance of WDM channels, each channel have bit rate of 40 Gbps, are proposed. The proposed optical link configuration consist of optical phase conjugator (OPC) placed at middle of total transmission length, and dispersion management (DM) as a role of compensating dispersion cumulated in transmission line. It is confirmed that Q-factor of total channels are improved by combining OPC and DM in optical transmission link as a result of following fact; DM not only mitigate the cumulated dispersion in total transmission line but also help OPC to compensate optical nonlinearities. And, it is confirmed that the improvement of Q-factor of overall WDM channels depends on net residual dispersion (NRD) of optical link.

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Compensation Characteristics of WDM Signals Depending on RDPS Slope of Fiber Span in Dispersion Managed Optical Transmission Links (분산 제어 광전송 링크에서 중계 구간의 RDPS 기울기에 따른 WDM 신호의 보상 특성)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.17 no.2
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    • pp.208-217
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    • 2013
  • The optimal residual dispersion per span (RDPS) slope is induced through the analyses of the compensation characteristics of the wavelength division multiplexed (WDM) channels depending on RDPS slope in the optical links with a dispersion management (DM) and an optical phase conjugation. The simulation results show that the effective launch power of WDM is more increased and the performance difference between the channels is more decreased as RDPS slope is more increased. The simulation results also show that the effective net residual dispersion (NRD) range is more increased as RDPS slope is more increased, and consequently, it is more advantageous to use the large RDPS slope for implementing the flexible optical links.

Proposal and Evaluation of Ultra High Speed Wireless Cell Backbone Networks (도시형 초고속 무선통신 셀백본망의 제안 및 평가)

  • 신천우
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.2B
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    • pp.151-157
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    • 2004
  • In this paper, we investigated ultra high speed wireless communication cell backbone net of city using of wireless communication transceiver for millimeter wave band. A new type of 60GHz wave band wireless transceiver using NRD waveguide. This 60㎓ transceiver has excellent signal's absorption characteristics of oxygen molecule than the other millimeter wave bands. We constructed to wireless networks interval within 500m to 3km on wireless backbone node using 60GHz transceivers, and did it so that city type wireless communication cell backbone networks of 155.52MbpsATM(OC-3) may be possible. Therefore, if use transceiver, it is possible that city type ultra high speed wireless communication cell backbone networks construction of 100Mbps, 155.52Mbps, 622Mbps, 1Gbps, and 1.2Gbps degrees.

Transmission Performance of 960 Gbps WDM Signals Depends on Dispersion Compensation Configurations (분산 보상 구조에 따른 960 Gbps WDM 신호의 전송 성능)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.15 no.2
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    • pp.248-255
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    • 2011
  • An investigation has been carried out, by computer simulation, to evaluate the impact of dispersion compensation configurations on 960 Gbps wavelength division multiplexed (WDM) system with optical phase conjugator (OPC). The considered dispersion compensation configurations in this research are conventional one-end type and bi-end type. One-end and bi-end type are made by using one dispersion compensating fiber (DCF) and two DCFs to decrease dispersion accumulated in one single mode fiber (SMF) span, respectively. It is found that bi-end compensation configuration offers the equal performance with that of one-end configuration in WDM system with residual dispersion per span (RDPS) of 400 ps/nm if net residual dispersion (NRD) had to be optimized in each cases.