• Bulletin of the Korean Mathematical Society
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• v.47 no.2
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• pp.319-339
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• 2010

In this paper, we prove that if $f^nf'\;-\;P$ and $g^ng'\;-\;P$ share 0 CM, where f and g are two distinct transcendental meromorphic functions, $n\;{\geq}\;11$ is a positive integer, and P is a nonzero polynomial such that its degree ${\gamma}p\;{\leq}\;11$, then either $f\;=\;c_1e^{cQ}$ and $g\;=\;c_2e^{-cQ}$, where $c_1$, $c_2$ and c are three nonzero complex numbers satisfying $(c_1c_2)^{n+1}c^2\;=\;-1$, Q is a polynomial such that $Q\;=\;\int_o^z\;P(\eta)d{\eta}$, or f = tg for a complex number t such that $t^{n+1}\;=\;1$. The results in this paper improve those given by M. L. Fang and H. L. Qiu, C. C. Yang and X. H. Hua, and other authors.

• Resources Recycling
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• v.11 no.3
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• pp.3-9
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• 2002

Relnoval of ammonia from aqueous solutions has been studied with zeolite and bentonite minerals. Zeolite and bentonite powder were supplied by a domestic company and used as delivered without further purification. The aqueous pH was found to increase by addition of zeolite or bentonite up to pH 8.5 from initial pH of 5.5∼5.7. From the C.E.C. measurement by ammonium acetate leaching method, the values of C.E.C. of zeolite and bentonite sample were observed to be 129.7 meq/100 gr and 65.1 meq/100 gr, respectively and Na+ ion accounted for the major part of total C.E.C. in both cases. In the removal of ammonia with zeolite and bentonite, physical adsorption of ammonium ion onto minerals was believed to contribute to the removal of it as well as the intrinsic cation exchange reaction. Finally, zeolite was found to be superior to bentonite in the removal of ammonia from aqueous solutions.

• Current Photovoltaic Research
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• v.4 no.3
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• pp.93-97
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• 2016

Light-emitting chromophores have been separated from silica spheres modified the surface with 3-(trimethoxysilyl)propylmethacrylate (TMSPM). The photoluminescence characteristics of the chromophores were investigated with various excitation wavelengths. The TMSPM was attached to the surface of silica spheres at $75^{\circ}C$. Large number of round shaped particles of the TMSPM was on the surface of silica spheres after 3 h reaction. The TMPSM was completely covered on the surface of the spheres after 6 h reaction. The surface modified silica spheres were soaked into acetone and stored for 20 days at ambient condition. The solution color slowly changed from light yellow to deep yellow with the increase of the storing time. The FTIR absorption peaks at 3348, 2869, 2927, 1715, 1453/1377, 1296, and $1120cm^{-1}$ represent C-OH, $R-CH_3$, $R_2-CH_2$, -C=O, C-H, C=C-H, and Si-O-Si absorption, respectively. The FTIR absorption peak at $1715cm^{-1}$ representing the ester -C=O stretching vibration for silica spheres stored for 20 days was increased compared with the spheres without aging. The UV-visible absorption peaks were at 4.51 eV (275 nm) and 3.91 eV (317 nm). There were two luminescence peaks at 2.51 eV (495 nm) and 2.25 eV (550 nm). The emission at 2.51 eV was dominant peak when the excitation energy was higher than 2.58 eV, and emission at 2.25 eV became dominant peak when the excitation energy was lower than 2.58 eV.

• International Commerce and Information Review
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• v.16 no.1
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• pp.247-269
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• 2014

This study is to present alternatives of strategical utilization of e-L/C in respective of transaction cost. Documentary credit is most used for trade importers' credit quality and the guarantee of the purchase price as the form of payment in export and import business dealings. The beneficiary must provide the documents required in a letter of credit in order to claim payment documents from the issuing bank, this leads to certain complexity during the procedure in practice, the preparation and the expenses of significant requirements and additional documents as well as in completing demands from the credit. In a result, there has been issues raised about the aspects of time and cost during the payment process. The outcome of such problems caused by delays in the existing trade procedure is the public to require the use of e-L/C in order to improve problems from the 'Transaction Cost' side. This study provides e-L/C's use to overcome the problems that are appearing from 'Transaction Cost' side as the aspect of time and the cost. In order to do so, we have to identify the problems in the original credit and e-L/C. Thus, provide the propose strategy of e-L/C from the Transaction Cost aspect.

• Journal of Digital Contents Society
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• v.19 no.7
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• pp.1263-1270
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• 2018

We investigated the e-learning platforms for higher education in developing countries. First, we introduced e-learning environmental factors such as ICT technology as well as ASEAN Cyber University (ACU) project for developing countries. And then, we presented Cambodian case as an example of e-learning platform for developing countries. We analyzed the national education policy and ICT environment as well as the demands and obstacles of e-learning in Cambodia. We derived e-learning strategies and plans based on the analysis results, and finally proposed e-learning platform C-MOOC Net. In order to verify the proposed scheme, we developed prototype of C-MOOC Net system which is implemented based on open software. As a result, we have met the requirement of networking the C-MOOC hub, supporting localization of local language and personalization of favorite courses respectively.

• Food Science of Animal Resources
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• v.39 no.6
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• pp.877-887
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• 2019

This study was performed to determine changes in mutagenicity and biogenic amine concentrations in sausages fermented with six different starter cultures treated with vitamins C and E. Six different types of fermented sausages with different combination of starter cultures were manufactured. T1, Pediococcus acidilactici; T2, P. pentosaceus and Staphylococcus carnosus; T3, S. carnosus, S. xylosus, Debaryomyces hansenii, Lactobacillus curvatus, and P. pentosaceus; T4, S. carnosus and L. sakei; T5, S. xylosus and L. plantarum; and T6, Penicillium nalgiovensis. After treatment with vitamins C and E in fermented sausages, changes in mutagenicity and biogenic amine concentrations were measured. The sausages fermented with Staphylococcus xylosus and Lactobacillus plantarum starter cultures showed the most effective antimutagenic activity (p<0.05). The mutagenicity was further decreased in the sausages treated with vitamins C and E (p<0.05), regardless of the starter cultures. The use of Pediococcus acidilactici, S. xylosus, L. plantarum, and Penicillium nalgiovensis as starter cultures was effective in decreasing biogenic amine concentrations (p<0.05). In addition, vitamin E was more effective in decreasing the biogenic amine concentrations than vitamin C. In conclusion, we recommend the use of S. xylosus and L. plantarum as starter cultures, in addition to the use of vitamins C and E, to reduce the potential risk of meat mutagens in fermented sausages.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.6
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• pp.487-490
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• 2010

This paper describes the elecrtical and optical characteristics of $N_2$ doped porous 3C-SiC films. Polycrystalline 3C-SiC thin films are anodized by $HF+C_2H_5OH$ solution with UV-LED exposure. The growth of in-situ doped 3C-SiC thin films on p-type Si (100) wafers is carried out by using APCVD (atmospheric pressure chemical vapor deposition) with a single-precursor of HMDS (hexamethyildisilane: $Si_2(CH_3)_6)$. 0 ~ 40 sccm $N_2$ was used for doping. After the growth of doped 3C-SiC, porous 3C-SiC is formed by anodization with $7.1\;mA/cm^2$ current density for anodization time of 60 sec. The average pore diameter is about 30 nm, and etched area is increased with $N_2$ doping rate. These results are attributed to the decrease of crystallinity by $N_2$ doping. Mobility is dramatically decreased in porous 3C-SiC. The band gaps of polycrystalline 3C-SiC films and doped porous 3C-SiC are 2.5 eV and 2.7 eV, respectively.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.269-277
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• 2016

Erm proteins methylate the specific adenine residue ($A_{2058}$, E. coli numbering) on 23S rRNA to confer the $MLS_B$ (macrolidelincosamide-streptogramin B) antibiotic resistance on a variety of microorganisms ranging from antibiotic producers to pathogens. When phylogenetic tree is constructed, two main clusters come out forming each cluster of Actinobacteria and Firmicutes. Two representative Erm proteins from each cluster were selected and their in vitro methylation activities were compared. ErmS and ErmE from Actinobacteria cluster exhibited much higher activities than ErmB and ErmC' from Firmicutes: 9 fold difference when ErmC' and ErmE were compared and 13 fold between ErmS and ErmB. Most of the difference was observed and presumed to be caused by N-terminal and C-terminal extra region from ErmS and ErmE, respectively because NT59TE in which N-terminal end 59 amino acids was truncated from wild type ErmS exhibited only 22.5% of wild type ErmS activity. Meanwhile, even NT59TE showed three and 2.2 times more activity when it was compared to ErmB and C, respectively, suggesting core region from antibiotic producers contains extra structure enabling higher activity. This is suggested to be possible through the extra region of 197RWS199 (from both ErmS and ErmE), 261GVGGSLY267 (from ErmS), and 261GVGGNIQ267 (from ErmE) and 291SVV293 (from ErmS) and 291GAV293 (from ErmE) by multiple sequence alignment.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1735-1743
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• 2010

The full-length genes gyrB (2,415 bp), parC (2,277 bp), and parE (1,896 bp) in Edwardsiella tarda were cloned by PCR with degenerate primers based on the sequence of the respective quinolone resistance-determining region (QRDR), followed by elongation of 5' and 3' ends using cassette ligation-mediated PCR (CLMP). Analysis of the cloned genes revealed open reading frames (ORFs) encoding proteins of 804 (GyrB), 758 (ParC), and 631 (ParE) amino acids with conserved gyrase/topoisomerase features and motifs important for enzymatic function. The ORFs were preceded by putative promoters, ribosome binding sites, and inverted repeats with the potential to form cruciform structures for binding of DNA-binding proteins. When comparing the deduced amino acid sequences of E. tarda GyrB, ParC, and ParE with those of the corresponding proteins in other bacteria, they were found to be most closely related to Escherichia coli GyrB (87.6% identity), Klebsiella pneumoniae ParC (78.8% identity), and Salmonella Typhimurium ParE (89.5% identity), respectively. The two topoisomerase genes, parC and parE, were found to be contiguous on the E. tarda chromosome. All 18 quinolone-resistant isolates obtained from Korea thus far did not contain subunit alternations apart from a substitution in GyrA (Ser83$\rightarrow$Arg). However, an alteration in the QRDR of ParC (Ser84$\rightarrow$Ile) following an amino acid substitution in GyrA (Asp87$\rightarrow$Gly) was detected in E. tarda mutants selected in vitro at $8{\mu}g/ml$ ciprofloxacin (CIP). A mutant with a GyrB (Ser464$\rightarrow$Leu) and GyrA (Asp87$\rightarrow$Gly) substitution did not show a significant increase in the minimum inhibitory concentration (MIC) of CIP. None of the in vitro mutants exhibited mutations in parE. Thus, gyrA and parC should be considered to be the primary and secondary targets, respectively, of quinolones in E. tarda.

• Kyungpook Mathematical Journal
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• v.49 no.3
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• pp.457-471
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• 2009

Let S = {a, b, c, ...} and ${\Gamma}$ = {${\alpha}$, ${\beta}$, ${\gamma}$, ...} be two nonempty sets. S is called a ${\Gamma}$-semigroup if $a{\alpha}b{\in}S$, for all ${\alpha}{\in}{\Gamma}$ and a, b ${\in}$ S and $(a{\alpha}b){\beta}c=a{\alpha}(b{\beta}c)$, for all a, b, c ${\in}$ S and for all ${\alpha}$, ${\beta}$ ${\in}$ ${\Gamma}$. An element $e{\in}S$ is said to be an ${\alpha}$-idempotent for some ${\alpha}{\in}{\Gamma}$ if $e{\alpha}e$ = e. A ${\Gamma}$-semigroup S is called an E-inversive ${\Gamma}$-semigroup if for each $a{\in}S$ there exist $x{\in}S$ and ${\alpha}{\in}{\Gamma}$ such that a${\alpha}$x is a ${\beta}$-idempotent for some ${\beta}{\in}{\Gamma}$. A ${\Gamma}$-semigroup is called a right E-${\Gamma}$-semigroup if for each ${\alpha}$-idempotent e and ${\beta}$-idempotent f, $e{\alpha}$ is a ${\beta}$-idempotent. In this paper we investigate different properties of E-inversive ${\Gamma}$-semigroup and right E-${\Gamma}$-semigroup.