• Journal of applied mathematics & informatics
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• v.8 no.3
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• pp.773-793
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• 2001

The explicit expressions for the 2n+1 primitive idempotents in R/sub pⁿ/ = F[x]/< x/sup pⁿ/ -1>, where F is the field of prime power order q and the multiplicative order of q modulo pⁿ is ø(pⁿ)/2(n≥1 and p is an odd prime), are obtained. An algorithm for computing the generating polynomials of the minimal QR cyclic codes of length pⁿ, generated by these primitive idempotents, is given and hence some bounds on the minimum distance of some QR codes of prime length over GF(q)(q=2, 3, ...) are obtained.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.2
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• pp.113-119
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• 2007

In this study, we investigated antimicrobial and cytotoxicity effects of Gelidium amansii L., which using methanol, dichloromethane and ethanol were extracted and fractionated into four different types : methanol (GAMM), hexane (GAMH), butanol (GAME) and aqueous (GAMA). The antimicrobial activity was increased in proportion to its concentration by the paper disc method. Among the solvent fractions, The methanol partition layer (GAMM) showed the strongest antimicrobial activities and cytotoxic effects on all cancer cell lines. We also observed quinone reductase (QR) induced effects in all fraction layers of GA on HepG2 cells. The QR induced effects of GAMM on HepG2 cells at $40{\mu}g/mL$ concentration indicated 2.5 with a control value of 1.0.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.288-293
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• 2008

In this study, we investigated the anticancer activity of Makgeoly (MG). MG was fractionated into four fractions by using solvent partition method, affording hexane (MGH), methanol (MGM), butanol (MGB) and aquous (MGA) soluble fractions. We determined the cytotoxicity of these four fractions in four kinds of cancer cell lines, such as HepG2, MCF-7, B16-F10 and HT29 by MTT assay. Among the various fractions, the MGM showed the strongest cytotoxic effects on all cancer cell lines. The morphological changes such as membrane shrinking and blebbing of cells were also observed by MGM treatment in HepG2 cell. In addition, we observed quinone reductase (QR) activity stimulating effects in all fraction layers of MG on HepG2 cells. QR activity increased approximately 2.6 and 2.1 times in MGM and MGH treated HepG2 cell at $100{\mu}g/mL$, respectively, compared to that in control value. Although further studies are needed, the present work could suggest that the fin of MG has a potential to be used as a chemopreventive agent against cancer.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.217-219
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• 2005

This paper describes implicit restated arnoldi method algorithm and Its application to small size power systems In order to observe the salient features of IRAM algorithm. Two area system with 36 state variables and England 39-bus system with 150 state variables have been tested using IRAM, and the eigenvalue results of IRAM are compared with those of the results obtained from QR method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9C
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• pp.734-742
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• 2008

In spatially multiplexed MIMO systems that enable high data rate transmission over wireless communication channels, the spatial demultiplexing at the receiver is a challenging task and various demultiplexing methods have been developed. Among the previous methods, maximum likelihood detection with QR decomposition and M-algorithm (QRM-MLD), sphere decoding (SD), QOC, and MOC schemes have been reported to achieve a (near) maximum likelihood (ML) hard decision performance. In general, however, the reliability of soft output of these schemes is not satisfactory. In this paper, we propose a method which enhances the reliability of soft output. By computer simulations, we demonstrate the improved performance by the proposed method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9C
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• pp.771-777
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• 2010

This paper proposes a new signal detection method, called QR-OSIC with Candidates (QOC) method, for spatially multiplexed multiple input multiple output (MIMO) systems. By using the ordered successive interference cancellation (OSIC) algorithm and the maximum likelihood (ML) metric, the proposed method achieves near-ML performance without requiring a large number of candidates. Although the proposed method can be used for both hard and soft decoding systems, it is especially useful for soft decoding systems since the LLR values for all the bits can be efficiently computed without using LLR estimation. The proposed method is also suitable for VLSI implementation since it leads to fixed throughput system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.3
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• pp.276-281
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• 2019

Food printers must use food ink cartridges approved by the Ministry of Food and Drug Safety (MFDS). A 2D bar code is used to read whether the ink cartridge is authentic. However, since the dye is diverged by heat pressure and printed, the barcode is contaminated. In this paper, we propose a pre-processing algorithm to solve the problem of barcode contamination by food coloring dust in a latte art printer. The algorithm is based on various morphological operations. We apply this algorithm before reading contaminated barcode images with a general QR code reader. It has been confirmed that, as compared with the existing QR code reader, the contamination rate that can be perceived is increased from 25% to 40% and even at a contamination rate of 45%, the recognition rate reaches 50%.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.295-297
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• 2005

This paper presents a novel current driving method for the synchronous rectifier (SR) in a Flyback topology. The proposed current driven synchronous rectifier features low Power loss, good performance and the gate voltage of FET in the synchronous rectifier is easily controlled by zener voltage. The proposed SR driving method is implemented in a 200W Flyback converter with 400Vdc input and achieved excellent performance at full load.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1395-1397
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• 2005

This paper presents a novel current driving method for the synchronous rectifier(SR) in a flyback topology. The proposed current driven synchronous rectifier features low power loss, good performance and the gate voltage of FET in the synchronous rectifier is easily controlled by resistor ratio. The proposed SR driving method is implemented in a 200W Flyback converter with 400Vdc input and achieved excellent performance at full load.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.201-203
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• 1998

This paper presents the framework for analysis of small-signal stabili1ty. In this framework the equilibrium points of system DAE model are traced using continuation method and instability points are determined on the solution path. Especially Implicit shift QR-modified ARnoldi method is utilized to calculated the rightmost eigenvalues. ISPS measure is utilized to determine critical parameters.