• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.3
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• pp.229-235
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• 2019

The implementation of an in-band full-duplex wireless communication system is demonstrated in this study. In the analog/RF domain, the self-interference(SI) signal is reduced using a separate antenna for the transmitter and receiver paths, and most of the SI signal is canceled in the digital domain. A software defined radio(SDR) is used to implement the in-band full-duplex wireless communication system. The USRP X310 device uses transmitting and receiving antennas. By adjusting the gain of the transmitting and receiving ends of the SDR device, the magnitude of the SI signal entering the receiving antenna, and the size of the received signal from the outside, are both set to -64 dB. To verify the in-band full-duplex wireless communication performance, the source data is image and orthogonal frequency-division multiplexing is used for modulation. A WiFi standard frame with a carrier frequency of 2.67 GHz and bandwidth of 20 MHz is used. In the received signal, the SI signal is canceled by digital signal processing and the SI signal is attenuated by up to 34 dB. OFDM demodulation was impossible when the SI signal was not removed. However, the bit error rate is reduced to $2.63{\times}10^{-5}$ when the SI signal is attenuated by 34 dB, and no error is detected in the 100 Mbit data output as a result of passing through the Viterbi decoder.

• World Technopolis Review
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• v.8 no.1
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• pp.59-70
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• 2019

Where is a better place to live? In the coming era, this should be more than simply a livable place. It should be an adaptable place that has a flexible system adaptable to any new situation in terms of diversity. Customization and real-time operation are needed in order to realize this technologically. We expect a smart city to have a flexible system that applies technologies of self-monitoring and self-response, thereby being a promising city model towards being a better place to live. Energy demand and supply is a crucial issue concerning our expectations for the flexible system of a smart city because it is indispensable to comfortable living, especially city living. Although it may seem that energy diversification, such as the energy mix of a country, is a matter of overriding concern, the central point is the scale of place to build grids for realizing sustainable urban energy systems. A traditional hard energy path supported by huge centralized energy systems based on fossil and nuclear fuels on a national scale has already faced difficult problems, particularly in terms of energy flexibility/resilience. On the other hand, an alternative soft energy path consisting of small diversified energy systems based on renewable energy sources on a local scale has limitations regarding stability, variability, and supply potential despite the relatively light economic/technological burden that must be assumed to realize it. As another alternative, we can adopt a holonic path incorporating an alternative soft energy path with a traditional hard energy path complimentarily based on load management. This has a high affinity with the flexible system of a smart city. At a system level, the purpose of all of the paths mentioned above is not energy itself but the service it provides. If the expected energy service is fixed, the conclusive factor in choosing a more appropriate system is accessibility to the energy service. Accessibility refers to reliability and affordability; the former encompasses the level of energy self-sufficiency, and the latter encompasses the extent of energy saving. From this point of view, it seems that the small diversified energy systems of a soft energy path have a clear advantage over the huge centralized energy systems of a hard energy path. However, some insuperable limitations still remain, so it is reasonable to consider both energy systems continuing to coexist in a multiplexing energy system employing a holonic path to create and maintain reliable and affordable access to energy services that cover households'/enterprises' basic energy needs. If this is embodied in a smart city concept, this is nothing else but smart energy inclusion. In Japan, following the Fukushima nuclear accident in 2011, a trend towards small diversified energy systems of a soft energy path intensified in order to realize a nuclear-free society. As a result, the Government of Japan proclaimed in its Fifth Strategic Energy Plan that renewable energy must be the main source of power in Japan by 2050. Accordingly, Sony vowed that all the energy it uses would come from renewable sources by 2040. In this situation, it is expected that smart energy inclusion will be achieved by the Japanese version of a smart grid based on the concept of a minimum cost scheme and demand response.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.9-16
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• 2022

In this paper, we propose a plan to design and utilize the RDBS(Record Block Data file management System) so that data can be recovered when data files in the Combat Management System are mismatched. The CMS(Combat Management System) manages the same files in multiple IPN(Infomation Processing Node) repositories to support multiplexing. However, mismatches in data files can occur due to equipment maintenance or user immaturity. The existing CMS does not manage the history of changes in data files, and when a mismatch occurs, data file were synchronized based on the latest date. But, It is difficult to say that files with the latest date have the highest reliability, and once the file synchronization has progressed, it cannot be recovered with pre-synchronization data. To solve this problem, data was stored and synchronized in units of record blocks using RDBS proposed in this paper, and the Rsync algorithm was used to reduce the overhead of file synchronization due to units of record blocks. SW applied with RDBS was tested for performance in a simulated environment, and it was confirmed that it could be applied to CMS through normal operation confirmation.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.4
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• pp.23-29
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• 2017

The packaged optical fiber Bragg grating sensors which were networked by multiplexing the Bragg grating sensors with WDM technology were investigated in application for the structural health monitoring of the marine trestle structure transporting the ship. The optical fiber Bragg grating sensor was packaged in a cylindrical shape made of aluminum tubes. Furthermore, after the packaged optical fiber sensor was inserted in polymeric tube, the epoxy was filled inside the tube so that the sensor has resistance and durability against sea water. The packaged optical fiber sensor component was investigated under 0.2 MPa of hydraulic pressure and was found to be robust. The number and location of Bragg gratings attached at the trestle were determined where the trestle was subject to high displacement obtained by the finite element simulation. Strain of the part in the trestle being subjected to the maximum load was analyzed to be ${\sim}1000{\mu}{\varepsilon}$ and thus shift in Bragg wavelength of the sensor caused by the maximum load of the trestle was found to be ~1,200 pm. According to results of the finite element analysis, the Bragg wavelength spacings of the sensors were determined to have 3~5 nm without overlapping of grating wavelengths between sensors when the trestle was under loads and thus 50 of the grating sensors with each module consisting of 5 sensors could be networked within 150 nm optical window at 1550 nm wavelength of the Bragg wavelength interrogator. Shifts in Bragg wavelength of the 5 packaged optical fiber sensors attached at the mock trestle unit were well interrogated by the grating interrogator which used the optical fiber loop mirror, and the maximum strain rate was measured to be about $235.650{\mu}{\varepsilon}$. The modelling result of the sensor packaging and networking was in good agreements with experimental result each other.

• Journal of Animal Science and Technology
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• v.51 no.3
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• pp.201-206
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• 2009

Seventeen porcine microsatellite (MS) markers recommended by the EID+DNA Tracing EU project, ISAG and Roslin institute were selected for the use in porcine individual and brand identification. The MSA, CERVUS, FSTAT, GENEPOP and API-CALC programs were applied for calculating heterozygosity indices. By considering the hetreozygosity value and PCR product size of each marker, we established a MS marker set composed of 13 MS markers (SW936, SW951, SW787, S00090, S0026, SW122, SW857, S0005, SW72, S0155, S0225, SW24 and SW632) and two sexing markers. The expected probability of identity among genotypes of random individuals (PI), probability of identity among genotypes from random half sibs ($PI_{half-sibs}$) and among genotypes of random individuals, probability of identity among genotypes from random sibs($PI_{sibs}$) were estimated as $2.47\times10^{-18}$, $6.39\times10^{-13}$ and $1.08\times10^{-8}$, respectively. The results indicate that the established marker set can provide a sufficient discriminating power in both individual and parentage identification for the commercial pigs produced in Korea.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.108-116
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• 2009

In this paper, we propose a Ethernet based audio distribution system with a new L1/L2 hybrid switching scheme, and evaluate its performance. The proposed scheme not only offers guaranteed low latency and jitter characteristics that are essentially required for the distribution of high-quality uncompressed audio traffic, and but also provide an efficient transmission of data traffic on the Ethernet environment. The audio distribution system with a proposed scheme consists of a master node and a number of relay nodes, and all nodes are mutually connected as a daisy-chain topology through up and downlinks. The master node generates an audio frame for each cycle of 125us, and the audio frame has 24 time slotted audio channels for carrying stereo 24 channels of 16-bit PCM sampled audio. On receiving the audio frame from its upstream node via the downlink, each intermediate node inserts its audio traffic to the reserved time slot for itself, then relays again to next node through its physical layer(L1) transmission - repeating. After reaching the end node, the audio frame is loopbacked through the uplink. On repeating through the uplink, each node makes a copy of audio slot that node has to receive, then play the audio. When the audio transmission is completed, each node works as a normal L2 switch, thus data frames are switched during the remaining period. For supporting this L1/L2 hybrid switching capability, we insert a glue logic for parsing and multiplexing audio and data frames at MII(Media Independent Interlace) between the physical and data link layers. The proposed scheme can provide a good delay performance and transmission efficiency than legacy Ethernet based audio distribution systems. For verifying the feasibility of the proposed L1/L2 hybrid switching scheme, we use OMNeT++ as a simulation tool with various parameters. From the simulation results, one can find that the proposed scheme can provides outstanding characteristics in terms of both jitter characteristic for audio traffic and transmission efficiency of data traffics.

• Journal of Animal Science and Technology
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• v.55 no.3
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• pp.185-194
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• 2013

Microsatellite markers have been a useful genetic tool in determining diversity, relationships and individual discrimination studies of livestock. The level of genetic diversity, relationships among two Korean indigenous chicken brand populations (Woorimatdag: WR, Hanhyup3: HH) as well as two pure populations (White Leghorn: WL, Rhode Island Red: RIR) were analyzed, based on 26 MS markers. A total of 191 distinct alleles were observed across the four chicken populations, and 47 (24.6%) of these alleles were unique to only one population. The mean $H_{Exp}$ and PIC were estimated as 0.667 and 0.630. Nei's $D_A$ genetic distance and factorial correspondence analysis (FCA) showed that the four populations represented four distinct groups. However, the genetic distance between each Korean indigenous chicken brand (WR, HH) and the pure population (WL, RIR) were threefold that among the WR and HH. For the STRUCTURE analyses, the most appropriate number of clusters for modeling the data was determined to be three. The expected probabilities of identity among genotypes of random individuals (PI) were calculated as $1.17{\times}10^{-49}$ (All 26 markers) and $1.14{\times}10^{-15}$, $7.33{\times}10^{-20}$ (9, 12 with the highest PI value, respectively). The results indicated that the brand chicken breed traceability system employing the own highest PI value 9 to 12 markers, and might be applicable to individual identification of Korean indigenous chicken brand.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.699-705
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• 2007

The present study was conducted to investigate the genetic characteristic and to establish the parentage verification system of the Korean native horse(KNH). A total number of 192 horses from six horse breeds including the KNH were genotyped using 17 microsatellite loci. This method consisted of multiplexing PCR procedure. The number of alleles per locus varied from 5 to 10 with a mean value of 7.35 in KNH. The expected heterozygosity and observed heterozygosity were ranged from 0.387 to 0.841(mean 0.702) and from 0.429 to 0.905(mean 0.703), respectively. The total exclusion probability of 17 microsatellite loci was 0.9999. Of the 17 markers, AHT4, AHT5, CA425, HMS2, HMS3, HTG10, LEX3 and VHL20 marker have relatively high PIC value(>0.7). This study found that there were specific alleles, P allele at AHT5, Q allele and R allele at ASB23, H allele at CA425, S allele at HMS3, J allele at HTG10 and J allele at LEX3 marker in KNH when compared with other horse populations. Also, the results showed two distinct clusters: the Korean native horse cluster(Korean native horse, Mongolian horse), and the European cluster(Jeju racing horse, Thoroughbred horse). These results present basic information for detecting the genetic markers of the KNH, and has high potential for parentage verification and individual identification of the KNH.