• Bulletin of the Korean Mathematical Society
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• v.53 no.6
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• pp.1753-1769
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• 2016

This paper is concerned with the quasilinear $Schr{\ddot{o}}dinger$ system $$(0.1)\;\{-{\Delta}u+a(x)u-{\Delta}(u^2)u=Fu(u,v)+h(x)\;x{\in}{\mathbb{R}}^N,\\-{\Delta}v+b(x)v-{\Delta}(v^2)v=Fv(u,v)+g(x)\;x{\in}{\mathbb{R}}^N,$$ where $N{\geq}3$. The potential functions $a(x),b(x){\in}L^{\infty}({\mathbb{R}}^N)$ are bounded in ${\mathbb{R}}^N$. By using mountain pass theorem and the Ekeland variational principle, we prove that there are at least two solutions to system (0.1).

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.6 s.237
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• pp.828-834
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• 2005

Recently, injection molded plastic optical products are widely used in many fields, because injection molding process has advantages of low cost and high productivity. However, there remains residual birefringence and residual stresses originated from flow history and differential cooling. The present study focused on developing a technique to measure the birefringence in optical plastic parts using R-G-B separation of white light. The main idea of an analysis comes from the fact that more information can be obtained from the distribution of retardation caused by different wavelengths. A complete system to give the quantitative values of retardation covering high order 2-D birefringence will be demonstrated. Further investigation is under way to improve the accuracy of the system using diodes as light sources.

• Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.8.1-8.11
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• 2016

To quantitatively estimate the influence of cuttlebone on the target strength (TS) of golden cuttlefish, the cuttlebone was carefully extracted from 19 live cuttlefish caught using traps in the inshore waters around Geojedo, Korea, in early May 2010 and the TS was measured using split-beam echosounders (Simrad ES60 and EY500). The TS-length relationships for the cuttlefish (before the extraction of cuttlebone, Fish Aquat Sci. 17:361-7, 2014) and the corresponding cuttlebone were compared. The cuttlebone length ($L_b$) ranged from 151 to 195 mm (mean $L_b$ = 168.3 mm) and the mass ($W_b$) ranged from 29.3 to 53.2 g (mean $W_b$ = 38.8 g). The mean TS values at 70 and 120 kHz were -33.60 dB (std = 1.12 dB) and -32.24 dB (std = 1.87 dB), respectively. The mean TS values of cuttlebone were 0.19 dB and 0.04 dB lower than those of cuttlefish at 70 and 120 kHz, respectively. For 70 and 120 kHz combined, the mean TS value of cuttlebone was -32.87 dB, 0.11 dB lower than that of cuttlefish (-32.76 dB). On the other hand, the mean TS value of cuttlebone predicted by the regression ($TS_b$ = 24.86 $log_{10}$ $L_b$ - 4.86 $log_{10}$ ${\lambda}$ - 22.58, $r^2$ = 0.85, N = 38, P < 0.01) was -33.10 dB, 0.04 dB lower than that of cuttlefish predicted by the regression ($TS_c$ = 24.62 $log_{10}$ $L_c$ - 4.62 $log_{10}$ ${\lambda}$ - 22.64, $r^2$ = 0.85, N = 38, P < 0.01). That is, the contribution of cuttlebone to the cuttlefish TS determined by the measured results was slightly greater than that by the predicted results. These results suggest that cuttlebone is responsible for the TS of cuttlefish, and the contribution is estimated to be at least 99 % of the total echo strength.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.43-51
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• 2021

As the number of mobile devices has been increasing tremendously, system capacity should be enlarged in future next generation communication, such as the fifth-generation (5G) and beyond 5G (B5G) mobile networks. For such future networks, non-orthogonal multiple access (NOMA) has been considered as promising multiple access technology. In this paper, to reduce both latency and complexity in existing NOMA, we propose non-successive interference cancellation (SIC) NOMA with asymmetric binary pulse amplitude modulation (2PAM), nearly without bit-error rate (BER) loss. First, we derive the closed form of BER expressions for non-SIC NOMA with asymmetric 2PAM, especially under Rayleigh fading channels. Then, it is shown that the BER performance of the stronger channel user who is supposed to perform SIC in conventional NOMA can be nearly achieved by the proposed non-SIC NOMA with asymmetric 2PAM, especially without SIC. Furthermore, we also show that the BER performance of the weaker channel user in conventional NOMA can be more closely achieved by the proposed non-SIC NOMA with asymmetric 2PAM. These BERs are shown to be achieved over the part of the power allocation range, which is consistent with the NOMA principle of user fairness. As a result, the non-SIC NOMA scheme with asymmetric 2PAM could be considered as a promising NOMA scheme toward next generation communication.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.778-780
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• 2006

High performance liquid chromatography (HPLC) was used for the analysis of the lignans eleutheroside B and eleutheroside E in the fruits of Acanthopanax species. A reverse-phase system using a gradient of $H_2O$ and acetonitrile as the mobile phase was developed and detection was at 210 nm. The analysis was successfully carried out within 20 min. The content of eleutheroside B and eleutheroside E in Acanthopanax species was measured in the fruits of A. senticosus (0.58 and $1.66\;{\mu}g/mg$, respectively), A. sessiliflorus (1.15 and $8.49\;{\mu}g/mg$, respectively), A. koreanum (2.16 and $1.80\;{\mu}g/mg$, respectively), and A. divaricatus (1.06 and $7.08\;{\mu}g/mg$, respectively).

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.953-958
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• 1996

A simple and rapid ELISA (enzyme-linked immunosorbent assay) system for fumonisins, a group of potentent carcinogen, was developed. To produce anti-fumonisin B1 (FB1) antibodies, FB1 conjugated to keyhole lympet hemocyanin (KLH) and Freund's adjuvant were immunized into rabbits subcutaneously 3 times. From one of the antisera showing high titer and good competition with the toxin in ELISA, polyclonal antibodies were purified. The cross-reactivities of the antibodies against fumonisin $B_1,\;B_2\;and\;B_3$ were 100%, 69%, and 166%, respectively. When competitive direct ELISA established by use of the antibody was applied to the spike test of $FB_1$ onto uncontaminated corns, the assay recovery was unstable unless 75% methanol extracts of corn were diluted to 1/100 with buffer. In that condition the mean ELISA recovery of FB1 from corns spiked $1-30\;{\mu}g/g$ was 67% and stable (coefficient of variation (CV) of each recovery percentage, 3.4%). The results suggest that the ELISA system established in this study needs no cleanup procedure and therefore would be powerful to screen a large number of corn samples contaminated with fumonisins.

• IMMUNE NETWORK
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• v.5 no.2
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• pp.68-77
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• 2005

Background: Costimulation is a critical process in Ag-specific immune responses. Both B7.1 and CD28 molecules have been reported to stimulate T cell responses during antigen presentation. Therefore, we tested whether Ag-specific immune responses as well as protective immunity are influenced by coinjecting with B7.1 and CD28 cDNAs in a mouse HSV-2 challenge model system. Methods: ELISA was used to detect levels of antibodies, cytokines and chemokines while thymidine incorporation assay was used to evaluate T cell proliferation levels. Results: Ag-specific antibody responses were enhanced by CD28 coinjection but not by B7.1 coinjection. Furthermore, CD28 coinjection increased IgG1 production to a significant level, as compared to pgD+pcDNA3, suggesting that CD28 drives Th2 type responses. In contrast, B7.1 coinjection showed the opposite, suggesting a Th1 bias. B7.1 coinjection also enhanced Ag-specific Th cell proliferative responses as well as production of Th1 type cytokines and chemokines significantly higher than pgD+pcDNA3. However, CD28 coinjection decreased Ag-specific Th cell proliferative responses as well as production of Th1 types of cytokines and chemokine significantly lower than pgD+pcDNA3. Only MCP-1 production was enhanced by CD28. B7.1 coimmunized animals exhibited an enhanced survival rate as well as decreased herpetic lesion formation, as compared to pgD+pcDNA3. In contrast, CD28 vaccinated animals exhibited decreased survival from lethal challenge. Conclusion: This study shows that B7.1 enhances protective Th1 type cellular immunity against HSV-2 challenge while CD28 drives a more detrimental Th2 type immunity against HSV-2 challenge, supporting an opposite role of B7.1 and CD28 in Ag-specific immune responses to a Th1 vs Th2 type.

• Biomedical Science Letters
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• v.11 no.1
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• pp.57-61
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• 2005

The number of sites at which a protein can be readily cleaved by a proteolytic enzyme is greatly influenced by its three-dimensional structure. For native, properly-folded proteins both the rate of cleavage and number of sites at which cleavage takes place are usually much less than for the denatured protein. In order to compare the tertiary structure of recombinant HepG2 type glucose transporter with that of its native counterpart in the erythrocyte, the pattern of tryptic cleavage of the protein expressed in insect cell membranes was therefore examined. After 30 minutes digestion, a fragment of approximate Mr 19,000-21,000 was generated. In addition to this, there were two less intensely stained fragments of apparent Mr 28,000 and 17,000. The pattern of labelling was similar up to 2 hours of digestion. However, the fragments of Mr 19,000-21,000 and Mr 17,000 were no longer detectable after 4 hours digestion. The observation of a very similar pattern of fragments yielded by tryptic digestion of the HepG2 type transporter expressed in insect cells suggests that the recombinant protein exhibits a tertiary structure similar if not identical to that of its human counterpart. Also, the endogenous sugar transporter(s) present in Sf21 cells did not bind cytochalasin B, the potent transporter inhibitor. Therefore, the baculovirus/Spodoptera frugiperda (Sf) cell expression system could be very useful for production of large amounts of human glucose transporters, heterologously.

• Journal of Life Science
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• v.28 no.9
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• pp.1007-1015
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• 2018

The E6-associated protein (E6AP) is known to induce the ubiquitination and proteasomal degradation of HCV core protein and thereby directly impair capsid assembly, resulting in a decline in HCV replication. To counteract this anti-viral host defense system, HCV core protein has evolved a strategy to inhibit E6AP expression via DNA methylation. In the present study, we further explored the mechanism by which HCV core protein inhibits E6AP expression. HCV core protein upregulated both the protein levels and enzyme activities of DNA methyltransferase 1 (DNMT1), DNMT3a, and DNMT3b to inhibit E6AP expression via promoter hypermethylation in HepG2 cells but not in Hep3B cells, which do not express p53. Interestingly, p53 overexpression alone in Hep3B cells was sufficient to activate DNMTs in the absence of HCV core protein and thereby inhibit E6AP expression via promoter hypermethylation. In addition, upregulation of p53 was absolutely required for the HCV core protein to inhibit E6AP expression via promoter hypermethylation, as evidenced by both p53 knockdown and ectopic expression experiments. Accordingly, levels of the ubiquitinated forms of HCV core protein were lower in HepG2 cells than in Hep3B cells. Based on these observations, we conclude that HCV core protein evades ubiquitin-dependent proteasomal degradation in a p53-dependent manner.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.104.2-104.2
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• 2014

The RGB Bayer filter system consists of mosaic R, G, and B filters on the grid of photo sensors with which typical commercial DSLR (Digital Single Lens Reflex) cameras and CCD/CMOS cameras are taken. Many unique astronomical data taken with RGB Bayer filter systems are available, including transient objects, e.g., supernovae, variable stars, and solar system bodies. The utilization of such data in scientific research strongly requires reliable photometry transformation methods. In this work, we develop a series of formulae to derive magnitudes in the Johnson-Cousins BVR filter system from those in the RGB Bayer filter system.