• Journal of Korean Society of Transportation
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• 제23권6호
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• pp.115-125
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• 2005

The line planning problem is to determine the origin and destination stations of the lines with their frequencies so as to meet the OD demands. Since the advent of high speed trains, Korea railway is confronted with the urgent difficulty to reconstruct the line configuration with the frequencies of each line and each fleet type so the demands could be newly created as well as satisfied. Furthermore. the existing trains except the high speed trains suffer from a longer traveling time than before. Now, to reduce the passenger traveling time, the trains with the various halting patterns are run in the same line. Therefore, it is necessary to develop a new line planning model to consider the various halting patterns. Most of studies find the frequencies of each lines which meet the link traffic loads or minimum link frequencies. But these are based on the assumption of all stop patterns. Furthermore, it is not easy to include the actual constraints as like the minimum number of stops at a station, the maximum number of stops or a train, etc. We develop the line planning model considering not only the various halting patterns but also the actual constraints which is based on the multicommodity network flow model with the additional constraints.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제13권7호
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• pp.716-725
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• 2002

In this paper, we showed the applicability of power symmetric MSSI(Mid-Span Spectral Inversion) to the long-haul WDM system with the channel interference due to FWM(Four Wave Mixing). And we showed the degree of performance improvement. We used 1 dB EOP(Eye-Opening Penalty) criterion so as to evaluate the degree of compensation dependent on the variation of chirp parameter of optical pulse for the various input power in high speed tansmission system. And we evaluated the maximum input power of channel be able to be the signal to crosstalk noise (SNR) above 20 dB in the transmission link with the channel interference due to FWM. Consequently the proposed MSSI compensation method is capable to transmitting the total 68 WDM channels simultaneously with a 0.4 nm channel spacing and 5.3 dBm maximum input power in a 10 Gbps transmission link. Therefore the proposed power symmetric MSSI compensation method may be very useful for the implementation of long-haul wideband WDM transmission systems with relatively high power and improved performance.

• Journal of the Korea Society of Computer and Information
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• 제25권7호
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• pp.1-8
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• 2020

In this paper, we present an implementation of high speed image data transfer using XDMA for a video signal generation / acquisition device developed as a military test equipment. The technology proposed in this study obtains efficiency by replacing the method of copying data using the system buffer in the kernel area with the transmission and reception through the DMA engine in the FPGA. For this study, the device was developed as a PXIe platform in consideration of life cycle, and performance was maximized by using a low-cost FPGA considering mass productivity. The video I/O board implemented in this paper was tested by changing the AXI interface clock frequency and link speed through the existing memory copy method. In addition, the board was constructed using the DMA engine of the FPGA, and as a result, it was confirmed that the transfer speed was increased from 5~8Hz to 140Hz. The proposed method will contribute to strengthening defense capability by reducing the cost of device development using the PXIe platform and increasing the technology level.

• Journal of the Institute of Electronics Engineers of Korea TC
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• 제39권6호
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• pp.10-10
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• 2002

This paper introduces the high-resolution channel estimation technique which are used to estimate the first arrival multipath delay component. The proposed technique yields the precise estimate of the first time arrival which is directly related to the performance of TDOA-based position location. The proposed technique utilizes the transformed auto-correlation function of received common pilot signal in frequency domain, its samples compose the hermitian Toeplitz matrix at sequel. Then the time delay components could be estimated with precision by the analysis of eigen-structure of corresponding matrix. In this paper, obeying the modified CODIT model, the performance of the PR-IPDL(Pseudo Random-Idle Period Downlink) and TA-IPDL(Time Aligned-Idle Period Downlink considered as 3GPP position location technique will be exploited systematically through the computer simulations with applying the proposed technique.

• Journal of the Institute of Electronics Engineers of Korea TC
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• 제39권6호
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• pp.268-276
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• 2002

This paper introduces the high-resolution channel estimation technique which are used to estimate the first arrival multipath delay component. The proposed technique yields the precise estimate of the first time arrival which is directly related to the performance of TDOA-based position location. The proposed technique utilizes the transformed auto-correlation function of received common pilot signal in frequency domain, its samples compose the hermitian Toeplitz matrix at sequel. Then the time delay components could be estimated with precision by the analysis of eigen-structure of corresponding matrix. In this paper, obeying the modified CODIT model, the performance of the PR-IPDL(Pseudo Random-Idle Period Downlink) and TA-IPDL(Time Aligned-Idle Period Downlink considered as 3GPP position location technique will be exploited systematically through the computer simulations with applying the proposed technique.

• Korean Journal of Clinical Laboratory Science
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• 제40권1호
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• pp.48-54
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• 2008

Nine types of staphylococcal enterotoxin (SE) genes (sea~see, seg~sej), 3 types of virulence genes (eta, etb, tst), mecA and 16S rRNA as internal positive control were detected from 187 clinical MRSA (methicillin resistance Staphylococcus aureus) strains isolated from a variety hospitalized patients in Daegu and Gyeongsangbuk-do areas using the multiplex PCR. The frequency of the S. aureus strains harboring recently reported SE genes (seg~sej) were found to be very high (65.9%) and greater than that of the strains harboring classical SE (sea~see) genes (47.8%) as previously established. Taking into account that the newly described pairs form SE genes (i.e., sec+seg+sei, seg+sei) were many, in the other hand, single form SE genes (i.e., seg, seh, sei and sej) were rarely detected. The S. aureus with pairs form enterotoxigenic genes become more potentially toxigenic strains. Furthermore, this work indicated a systematic association between the seg and sei genes and their high incidence among the S, aureus strains, which suggests that these two SE's could be an important phylogenetic link among the staphylococcal enterotoxins.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제65권5호
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• pp.843-850
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• 2016

In this paper, we propose a digital controller design process for the interleaved type of a boost PFC (Power Factor Correction) converter which can disperse the heat of the switching devices due to the interleaved topology. We establish a mathematical model of a boost PFC converter and propose a controller design method based on the root locus. The performance of the designed controller is verified by simulations. The measurement of the input voltage, inductor currents, and the converter output link voltage are needed for the control of the converter system which consists of a power unit and a control unit where a high-performance 32-bit microcontroller is used. The adjustment of A/D conversion timing is also needed to avoid high frequency noise generated when the switches on/off. It is illustrated by the real experiments that the designed control system with the properly adjusted ADC timing satisfies the given performance specifications of the interleaved boost PFC converter in the on-board slow battery charger.

• Journal of the Korean BIBLIA Society for library and Information Science
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• 제30권3호
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• pp.267-290
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• 2019

The purpose of this study is to investigate the current status and condition of continuing education to improve professionalism of school library and to suggest ways to improve continuing education. The survey was conducted for 69 librarians and school librarians teachers in elementary, middle and high school libraries in Goyang, Gyeonggi-do, and frequency analysis and cross analysis were conducted. The research results are as follows. First, the study found that librarians have a high interest in and participation in continuing education. Second, the type of continuing education with the highest percentage of participation was short-term training and training courses, and the link between educational content and practice was low. Third, managers' awareness needs to be improved, and regional constraints and the lack of suitable continuing education programs are the obstacles to continuing education. Fourth, preference for continuing education during working hours and vacation was emphasized. Through this, it was suggested that continuous and long-term continuing education, policy support for encouraging continuing education, development of continuing education courses for professionalism, manager's awareness call.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.29-38
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• 2023

Recent studies have highlighted the link between diseases and inflammation across our lifespan. Our sedentary lifestyle, high-calorie diet, chronic stress, chronic infections, and exposure to pollutants and xenobiotics, collectively intensify the course and recurrence of infections and inflammation in our bodies, promoting the prevalence of chronic diseases and aging. Given such phenomena and considering additional factors such as the frequency of prescription, and easy access to over-the-counter drugs, the need for anti-inflammatory therapeutics is ever-increasing. However, the readily available anti-inflammatory treatment option comes with a greater risk of side effects or high cost (biologics). Therefore in this growing competition of discovering and developing new potent anti-inflammatory drugs, we focused on utilizing the established knowledge of traditional medicine to find lead compounds. Since lead optimization is an indispensable step toward drug development, we applied this concept for the production of potent anti-inflammatory compounds achieved by structural modification of flavonoids. The derivative obtained through acetylation of myricetin, 3,3',4',5,5',7-hexaacetate myricetin, showed a greater inhibitory effect in the production of pro-inflammatory mediators such as nitric oxide, Prostaglandin E₂, and pro-inflammatory cytokines like interleukin-6, interleukin1β, in lipopolysaccharide-stimulated RAW264.7 mouse macrophage cells compared to myricetin. The increased potency of inhibition was in conjunction with an increased inhibitory effect on inducible nitric oxide synthase and cyclooxygenase-2 proteins. Through such measures, this study supports lead optimization for well-established lead compounds from traditional medicine using a simpler and greener chemistry approach for the purpose of designing and developing potent anti-inflammatory therapeutics with possibly fewer side effects and increased bioavailability.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제39C권12호
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• pp.1250-1260
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• 2014

In this paper, a novel resource scheduling, which is used for hub network based long distance airborne tactical communication, is proposed. Recently, some countries of the world has concentrated on developing data rate and networking performance of CDL, striving to keep pace with modern warfare, which is changed into NCW. And our government has also developed the next generation high capacity CDL. In hub network, a typical communication structure of CDL, hybrid FDMA/TDMA can be considered to exchange high rate data among multiple UAVs simultaneously, within limited bandwidth. However, due to different RTT and traffic size of UAV, idle time resource and unnecessary packet transmission delay can occur. And these losses can reduce entire efficiency of hub network in long distance communication. Therefore, in this paper, we propose RTT and data traffic size based UAV scheduling, which selects time/frequency resource of UAVs by using iterative sorting algorithm. The simulation results verified that the proposed scheme improves data rate and packet delay performance in low complexity.