• Bulletin of the Korean Mathematical Society
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• v.58 no.1
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• pp.21-30
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• 2021

In this paper, we prove some rigidity results about embedded minimal hypersurface M ⊂ ℝn+1 with compact ∂M that has one end which is regular at infinity. We first show that if M ⊂ ℝn+1 meets a hyperplane in a constant angle ≥ ��/2, then M is part of an n-dimensional catenoid. We show that if M meets a sphere in a constant angle and ∂M lies in a hemisphere determined by the hyperplane through the center of the sphere and perpendicular to the limit normal vector nM of the end, then M is part of either a hyperplane or an n-dimensional catenoid. We also show that if M is tangent to a C2 convex hypersurface S, which is symmetric about a hyperplane P and nM is parallel to P, then M is also symmetric about P. In special, if S is rotationally symmetric about the xn+1-axis and nM = en+1, then M is also rotationally symmetric about the xn+1-axis.

• Economic and Environmental Geology
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• v.32 no.5
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• pp.519-535
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• 1999

Precambrian metasedimetay rocks in the Sunchang Shear Zone (so-called Seologri and Yongamsan Formation) consist of black slate, phylite, mica schistm quartzite and rarely calc schist. The metamorphic rocks in the area have undergone at least three stages of metamorphism, which are two prograde (M1 and M2) and one contact metamorphism (M3). The metamorphism which made the most prevailing mineral assemblages in the area, is M2 stage metamorphism. The metamorphic grade of M2 methamorphism in metapelites increases from the Chlorite zone through Biotituzone, Garnet zone to Staurolite zone. The M1 stage metamorphism is recognized by kyanite and sillimanite pressure type regional metamorphism. The M3 stage methamorphism is represented in the contact boundary, which area is the chlorite zone and biotite zone near the Sunchang foliated granite and the namwon granite. The M3 stage methamorphism is characterized by andalusite bearing mineral assemblages. The peak temperature condition of M2 metamorphism estimated from coexising garnet and biotite (Kretz, 1990) is 518~598$^{\circ}C$.

• Archives of Pharmacal Research
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• v.16 no.4
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• pp.318-321
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• 1993

Cyanoaccetic acid hydrazide reacted with some 2-pyrazolin-5-one, isoxazol-5-one and 2-thiazolin-4-one and their ylidene derivatives to yield several new annelated pyran heterocycles. Structures wre established on the basis of elementary analyses and spectral data studies in addition to synthesis via other routes.

• Korean Journal of Ichthyology
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• v.29 no.2
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• pp.139-145
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• 2017

The spontaneous color mutant, albino individuals of genus Misgurnus, are rarely discovered in Korea and there are difficult to identify morphological species due to lack melanin pigmentation. In this study, we developed a genetic identification method for the species of albino Misgurnus individuals based on phylogenetic analysis by using recombination activating gene 1 (rag1) and cytochrome b (cytb) region of mitochondrial DNA. As a result of molecular phylogenetic analysis, three clades were identified as Misgurnus mizolepis, M. anguillicaudatus and M. mohoity. The homology of the cytb sequences of M. mohoity was best match to that of M. mohoity sequences in GenBank database. As a result of species identification of 25 albino Misgurnus individuals based on the phylogenetic tree, the red-eye type was identified as 16 M. anguillicaudatus and one M. mizolepis. The remaining three individuals were identified as one M. mizolepis ♀${\times}$M. anguillicaudatus ♂, and two M. mohoity ♀${\times}$M. anguillicaudatus ♂, respectively. In addition, the five black-eye type individuals were identified as one M. anguillicaudatus, three M. mizolepis and one M. mohoity. Therefore, this genetic identification method will be an useful techniques for species or hybrid identification in genus Misgurnus.

• Journal of Plant Biology
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• v.37 no.2
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• pp.237-244
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• 1994

Callus tissues derived from protoplast of Alnus hirsuta were shown to produce red pigments under the continuous light. The R4 cell line with high yield of the pigments was selected. One of the red pigments was identified as anthocyanin; glucose and galactose as sugar moiety and cyandin as aglycone, by spectroscopic analysis, cellulose TLC and GLC. Both callus growth and anthocyanin accumulation were remarkably stimulated by 2,4-D. The highest anthocyanin yield was observed when $1\;\mu\textrm{M}$ 2,4-D in combination with $0.1\;\mu\textrm{M}$ BAP was supplemented to the culture medium. In case of inorganic salts, anthocyanin yield was enhenced by reducing concentration of phosphate from 5.0 mM to 2.5 mM and by increasing the ratio of ${NO_3}^{-}$ type to 80% for total nitrogen source.source.

• Journal of Korea Multimedia Society
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• v.6 no.1
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• pp.161-166
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• 2003

This paper presents a high gain LNA for a bluetooth application using 0.25$\mu\textrm{m}$ CMOS technology. The conventional one stage LNA has a low power gain. The presented one stage LNA using a cascode inverter LNA with a voltage reference and without a choke inductor has an improved Power gain. Simulation results of the 2.4GHz designed LNA shows a high power gain of 21dB, a noise figure of 2.2dB, and the power consumption of 255mW at 2.5V power supply.

• Bulletin of the Korean Mathematical Society
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• v.60 no.3
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• pp.637-647
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• 2023

Let R be a commutative Noetherian ring, 𝔞 an ideal of R, M an arbitrary R-module and X a finite R-module. We prove a characterization for Hⁱ_𝔞(M) and Hⁱ_𝔞(X, M) to be 𝔞-weakly cofinite for all i, whenever one of the following cases holds: (a) ara(𝔞) ≤ 1, (b) dim R/𝔞 ≤ 1 or (c) dim R ≤ 2. We also prove that, if M is a weakly Laskerian R-module, then Hⁱ_𝔞(X, M) is 𝔞-weakly cofinite for all i, whenever dim X ≤ 2 or dim M ≤ 2 (resp. (R, m) a local ring and dim X ≤ 3 or dim M ≤ 3). Let d = dim M < ∞, we prove an equivalent condition for top local cohomology module H^d_𝔞(M) to be weakly Artinian.

• Microbiology and Biotechnology Letters
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• v.14 no.6
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• pp.495-500
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• 1986

Enzymatic micro-assay methods were studied those were capable of determining ammonia down to 10$^{-5}$M(0.01 $\mu$mole/ml) in the presence of other nitrogenous compounds such as protein and amino acid. Microquantities of ammonia (0.01-0.1 $\mu$mole) could be determined indirectly by measuring phosphorous, one of the products of the enzymatic reaction catalyzed by glutamine synthetase. In this reaction, L-glutamate, ATP and ammonium chloride were used as substrates, and phosphorous was formed in propotion to the concentration of ammonium chloride In the reaction mixture. Another procedure was examined in which glutamine synthetase reaction coupled with pyruvate kinase and lactate dehydrogenase reactions was used. One mililiter of the assay mixture contained; phosphoenol pyruvate, 3 mM, L-glutamate, 10 mM; ATP, 1mM: MgSO$_4$, 20 mM: KCl, 75mM: NADH, 0.2mM: Tris-HCl buffer(pH 7.0), 100mM; pyruvate kinase, 10 U: lactate dehydrogenase, 12 U and glutamine synthetase, 4 U. After preincubation for 20 min at 3$0^{\circ}C$, NH$_4$Cl was added and the rates of NADH oxidation were followed at 340nm. The effective range of this method was proved to be from 0.01 to 0.05 $\mu$mole/$m{\ell}$. Glutamine synthetase reaction coupled with glutamate synthase reaction could also be effectively used for determining microquantities of ammonia. The one mililiter assay mixture contained; ATP, 5mM: L-glutamate, 5mM; L-ketoglutarate, 5mM; MgCl$_2$, 15mM; NADPH, 0.15mM; Tris-HCl buffer(pH 7.0); 100mM; glutamine synthetase, 1U and glutamate synthase, 0.5U. After preincubation for 20min at 3$0^{\circ}C$ NH$_4$Cl was added and the rates of NADPH oxidation were followed at 340nm. The effective range of this procedure was appeared to be from 0.01 to 0.05$\mu$mole/$m{\ell}$.

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.507-509
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• 1997

Several new spiro compounds were synthesized via one-pot ternary condensation of isatin, malononitrile and each of thiobarbituric acid, barbituric, 3-methyl-pyrazolin-5-one, 1-phenyl-3-methyl-pyrazolin-5-one, acetylacetone, benzoylacetone, ethyl acetoacetate, phenacyl cyanide or ethyl-cyanoacetate dimer. Structures and reaction mechanisms were reported and supported via a second synthetic route.

• Journal of applied mathematics & informatics
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• v.26 no.3_4
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• pp.457-469
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• 2008

In this paper, we study the existence of positive solutions for the following nonlinear m-point boundary value problem with p-Laplacian: $\{{{{(\phi_p(u'))'\;+\;f(t,u(t))=0, \;0<t<1,} \atop u'(0)={\sum}{^{m-2}_{i=1}}\;a_iu'(\xi_i),} \atop u(1)={\sum}{^k_{i=1}}\;b_iu(\xi_i)\;-\;{\sum}{^s_{i=k+1}}\;b_iu(\xi_i)\;-\;{\sum}{^{m-2}_{i=s+1}}\;b_iu'(xi_i),}$ where ${\phi}_p(s)$ is p-Laplacian operator, i.e., ${\phi}_p(s)=\mid s\mid^{p-2}s$, p>1, ${\phi}_q\;=\;({\phi}_p)^{-1}$, $\frac{1}{p}+\frac{1}{q}=1$, $1\;{\leq}\;k\;{\leq}\;s\;{\leq}m\;-\;2$, $b_i\;{\in}\;(0,+{\infty})$ with $0\;<\;{\sum}{^k_{k=1}}\;b_i\;-\;{\sum}{^s_{i=k+1}}\;b_i\;<\;1$, $0\;<\;{\sum}{^{m-2}_{i=1}}\la_i\;<\;1$, $0\;<\;{\xi}_1\;<\;{\xi}_2\;<\;{\cdots}\;<\;{\xi}_{m-2}\;<\;1$, $f\;{\in}\;C([0,\;1]\;{\times}\;[0,\;+{\infty}),\;[0,\;+{\infty}))$. We show that there exists one or two positive solutions by using fixed-point theorem for operator on a cone. The conclusions in this paper essentially extend and improve the known results.