• 한국전산유체공학회지
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• 제5권2호
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• pp.47-54
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• 2000

A robust Navier-Stokes code has been developed to efficiently predict hypersonic flows in chemical nonequilibrium. The HLLE+ flux discretization scheme is used to improve accuracy and robustness of hypersonic flow analysis. An efficient LU approximate factorization method is also used to solve the flow equations and species continuity equations in fully coupled fashion to implicitly treat stiff source terms of chemical reactions. The HLLE+ scheme shows lower grid dependency for the wall heating rates than other schemes. The developed code has been used to compute chemical nonequilibrium air flow through expanding hypersonic nozzle and past two and three dimensional blunt-nosed bodies. The results are in good agreement with existing numerical and experimental results.

• 한국약용작물학회지
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• 제18권1호
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• pp.34-39
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• 2010

Machilus thunbergii was an important medicinal resource and distributed widely in China. In this study, the bioactivities of dichloromethane fraction (DF) and water fraction (AF) from Machilus thunbergii methanol extract were investigated. Total phenolic contents of DF and AF were 57.90 mg Gal/g and 189.92 mg Gal/g, and total flavonoid contents were 17.34 mg Que/g and 58.38 mg Que/g respectively. The $EC_{50}$ for DPPH radical scavenging activity of DF and AF were $24.37\;{\mu}g/m{\ell}$ and $2.10\;{\mu}g/m{\ell}$. Reducing power and hydroxyl radical scavenging activities of AF were higher than those of DF. The $\alpha$-glucosidase inhibitory activity of AF ($IC_{50}\;=\;1.13\;{\mu}g/m{\ell}$) was higher than that of DF ($IC_{50}\;=\;5.34\;{\mu}g/m{\ell}$). The cell viability was showed that only the DF had anti-proliferation effect on human cancer cell HT-29. These results suggested that both the DF and AF extract of Machilus thunbergii were potential materials for anti-diabetes and functional food for their radical scavenging activity.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 춘계 학술대회논문집
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• pp.123-127
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• 2005

The numerical analyses of the complicated flows are widely attempted in these days. Because of the enormous demanding memory and calculation time, parallel processing is used for these problems. In order to obtain calculation efficiency, it is important to choose proper domain decomposition technique and numerical algorithm. In this research we enhanced the efficiency of the CFDS code developed by ADD, using parallel computation and newly developed numerical algorithms. For the huge amount of data transfer between blocks non-blocking method is used, and newly developed data transfer algorithm is used for non-aligned block interface. Recently developed RoeM scheme is adpoted as a spatial difference method, and AF-ADI and LU-SGS methods are used as a time integration method to enhance the convergence of the code. Analyses of the flows around the ONERA M6 wing and the high angle of attack missile configuration are performed to show the efficiency improvement.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.4957-4976
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• 2016

This paper investigates the error performance of the amplify-and-forward (AF) relaying systems in the context of full-duplex (FD) communication. In addition to the inherent self-interference (SI) due to simultaneous transmission and reception, coexistent FD terminals may cause crosstalk. In this paper, we utilize the information exchange via the crosstalk channel to construct a particular distributed space-time code (DSTC). The residual SI is also considered. Closed-form pairwise error probability (PEP) is first derived. Then we obtain the upper bound of PEP in high transmit power region to provide more insights of diversity and coding gain. The proposed DSTC scheme can attain full cooperative diversity if the variance of SI is not a function of the transmit power. The coding gain can be improved by lengthening the frame and proper power control. Feasibility and efficiency of the proposed DSTC are verified in numerical simulations.

• Computers and Concrete
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• 제8권5호
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• pp.563-581
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• 2011

The signal-based acoustic emission (AE) characterization of concrete fracture process utilizing home-programmed AE monitoring system was performed for three kinds of static loading tests (Cubic-splitting, Direct-shear and Pull-out). Each test was carried out to induce a distinct fracture mode of concrete. Apart from monitoring and recording the corresponding fracture process of concrete, various methods were utilized to distinguish the characteristics of detected AE waveform to interpret the information of fracture behavior of AE sources (i.e. micro-cracks of concrete). Further, more signal-based characters of AE in different stages were analyzed and compared in this study. This research focused on the relationship between AE signal characteristics and fracture processes of concrete. Thereafter, the mode of concrete fracture could be represented in terms of AE signal characteristics. By using cement-based piezoelectric composite sensors, the AE signals could be detected and collected with better sensitivity and minimized waveform distortion, which made the characterization of AE during concrete fracture process feasible. The continuous wavelet analysis technique was employed to analyze the wave-front of AE and figure out the frequency region of the P-wave & S-wave. Defined RA (rising amplitude), AF (average frequency) and P-wave & S-wave importance index were also introduced to study the characters of AE from concrete fracture. It was found that the characters of AE signals detected during monitoring could be used as an indication of the cracking behavior of concrete.

• 한국해양바이오학회지
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• 제12권2호
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• pp.108-114
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• 2020

A variety of shellfish species sold for human consumption are available for purchase in the domestic fish market. The microalgae families inhabit the ocean, where planktons supply the main nutritional resource for the growth of shellfish. Some phytoplanktons produce toxic compounds that are accumulated in shellfish and ultimately cause toxicity in humans. This article reports the cytotoxicity of commercially available shellfish species. Accordingly, hot water extract (HWE) and an aqueous fraction of 50% methanol extract (MEE-AF) showed no significant cytotoxicity on the two cell lines (i.e., HL-60 and Vero cell lines), but 50% methanol extract (MEE) in 3, 6 samples showed 50% cytotoxic effects on HL-60 cells, and 1, 4 samples showed 40%, 20% cytotoxic effects on Vero cells, respectively. In addition, their consequential dichloromethane fractions (MEE-DF) exhibited significant toxicities at the highest concentration (1,000 ㎍/ml) on HL-60 and Vero cells. Since the shellfish samples showed cytotoxicity in the dichloromethane fraction, it is possible that the dichloromethane fraction contains marine toxins. Further research will be needed to identify the toxic components from each sample.

• Asian-Australasian Journal of Animal Sciences
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• 제23권11호
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• pp.1405-1411
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• 2010

Calpastatin (CAST), an endogenous inhibitor of the calpains, plays an important role in post-mortem tenderization of meat. The objectives of this study were to investigate single nucleotide polymorphisms (SNPs) in the bovine CAST gene and association with carcass and meat quality traits. A total of 212 cattle from commercial herds were tested in this study including 2 pure introduced breeds, 4 cross populations, and 3 pure Chinese native breeds. Five SNPs were identified at position 2959 (A/G), 2870 (G/A), 3088 (C/T), 3029 (G/A) and 2857 (C/T) in the CAST gene (GenBank Accession No. AF159246). Allele frequencies of SNP2959 and SNP2870 were 0.701 (A) and 0.462 (A), respectively. A general linear model was used to evaluate the associations between the two markers and 7 traits. The results showed that both SNP2959 and SNP2870 were significantly (p<0.01) associated with the Warner-Bratzler shear force (WBSF), while they had no significant association with the other 6 traits in the whole population. However, in Chinese native pure breeds, only SNP2870 had significant association with WBSF (p<0.05). The simultaneous analysis of two-marker genotype effects indicated animals containing the A/G haplotype (A for SNP2959 and G for SNP2870) tended to have lower shear force than those containing the G/A haplotype, and, especially, animals homozygous for the A/G haplotype had approximately 2 kg lower shear force than those homozygous for the G/A haplotype (p<0.01). These results suggested that both markers may be effective for the marker-assisted selection of meat quality traits in Chinese commercial herds, especially SNP2870 which can be used for Chinese native cattle.