• 충청수학회지
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• 제36권2호
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• pp.93-97
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• 2023

Let f : M → M be a diffeomorphism of two dimensional manifold M. If f has a homoclinic tangency associated to a hyperbolic periodic point p then there is a diffeomorphism g : M → M with C¹ close to f such that g is not continuum-wise expansive.

• Journal of Animal Science and Technology
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• 제44권5호
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• pp.633-642
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• 2002

1. ETEC F41 균주로부터 분리한 섬모항원의 분자량은 29.5 kDa으로 나타났으며, western blot을 통하여 섬모항원임을 확인하였다. 2. 분리한 섬모항원의 농도를 50 ${\mu}g$/$m\ell$, 200 ${\mu}g$/$m\ell$, 600 ${\mu}g$/$m\ell$로 조정 후 산란계에 접종하였다. 이 후 ELISA법을 이용하여 난황의 항체역가를 측정한 결과 최고치가 320,000(antigen 50${\mu}g$/$m\ell$), 450,000(antigen 200${\mu}g$/$m\ell$), 320,000(anti- gen 600${\mu}g$/$m\ell$)으로 나타났다. 3. F41난황항체와 K88, K99, 987P 섬모항원과의 교차반응을 ELISA법을 이용하여 조사해본 결과 난황항체를 30,000배 희석 시 교차반응이 없었다. 4. 실험실조건하에서 난황항체의 항원결합능력을 조사한 결과, 동결건조한 WSF을 2${\sim}$4 mg/$m\ell$ 첨가 시 균체의 농도가 $10^9$ CFU/$m\ell$에서 $10^5$ CFU/$m\ell$로 급격하게 감소하였다.

• Kyungpook Mathematical Journal
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• 제55권3호
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• pp.515-530
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• 2015

We say that (R, f, g) is an additive (m, n)-semihyperring if R is a non-empty set, f is an m-ary associative hyperoperation, g is an n-ary associative operation and g is distributive with respect to f. In this paper, we describe a number of characterizations of additive (m, n)-semihyperrings which generalize well-known results. Also, we consider distinguished elements, hyperideals, Rees factors and regular relations. Later, we give a natural method to derive the quotient (m, n)-semihyperring.

• 대한수학회보
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• 제54권6호
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• pp.2091-2106
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• 2017

The authors investigate f-biharmonic maps u : (M, g) ${\rightarrow}$ (N, h) from a Riemannian manifold into a Riemannian manifold with non-positive sectional curvature, and derive that if $\int_{M}f^p{\mid}{\tau}(u){\mid}^pdv_g$ < ${\infty}$, $\int_{M}{\mid}{\tau}(u){\mid}^2dv_g$ < ${\infty}$ and $\int_{M}{\mid}du{\mid}^2dv_g$ < ${\infty}$, then u is harmonic. When u is an isometric immersion, the authors also get that if u satisfies some integral conditions, then it is minimal. These results give an affirmative partial answer to conjecture 4 (generalized Chen's conjecture for f-biharmonic submanifolds).

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.629-630
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• 2006

To investigate sliding friction and wear behaviors of WC-Co/WC-Co pairs containing different WC grain sizes, the ball-on-disc test in air were carried out, where WC grain sizes a $0.5\;{\mu}m$ (F.G.) and $1.5\;{\mu}m$ (C.G.). The wear volume of F.G. pin for F.G. pin/C.G. disc is larger than that of F.G. pin for F.G. pin/F.G. disc due to higher friction coefficient, and the surfaces after wear test are richer in oxygen compared to those before test. Furthermore, the wear debris, which is composed of nona-scale grain, after the wear test are remarkably richer in oxygen than to those before test.

• Journal of Microbiology and Biotechnology
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• 제26권5호
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• pp.959-966
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• 2016

Chlorophyll synthase (ChlG) and bacteriochlorophyll synthase (BchG) have a high degree of substrate specificity. The BchG mutant of Rhodobacter sphaeroides, BG1 strain, is photosynthetically incompetent. When BG1 harboring chlG of Synechocystis sp. PCC 6803 was cultured photoheterotrophically, colonies arose at a frequency of approximately 10^-8. All the suppressor mutants were determined to have the same mutational change, ChlG_I44F. The mutated enzyme ChlG_I44F showed BchG activity. Remarkably, BchG_F28I, which has the substitution of F at the corresponding 28^th residue to I, showed ChlG activity. The K_m values of ChlG_I44F and BchG_F28I for their original substrates, chlorophyllide (Chlide) a and bacteriochlorophyllide (Bchlide) a, respectively, were not affected by the mutations, but the K_m values of ChlG_I44F and BchG_F28I for the new substrates Bchlide a and Chlide a, respectively, were more than 10-fold larger than those for their original substrates, suggesting the lower affinities for new substrates. Taken together, I44 and F28 are important for the substrate specificities of ChlG and BchG, respectively. The BchG activity of ChlG_I44F and the ChlG activity of BchG_F28I further suggest that ChlG and BchG are evolutionarily related enzymes.

• Journal of Plant Biology
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• 제29권1호
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• pp.53-65
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• 1986

The montane forests of Ulreung Island, Korea, were investigated by the ZM school method. By comparing the montane forests of this island with those of Korean Peninsula and of Japan, a new order, F a g e t a l i a m u l t i n e r v i s, a new alliance, F a l g i o n m u l t i n e r v i s, a new association, H e p a t i c o-F a g e t u m m u l t i n e r v i s and Rhododendron brachycarpum-Pinus parviflora community were recognized. The H e p a t i c o - F a g e t u m m u l t i n e r v i s was further subdivided into four subassociations; Subass. of Sasa kurilensis, Subass. of Rumohra standishii, Subass. of Rhododendron brachycarpum and Subass. of typicum. Each community was described in terms of floristic, structural and environmental features.

• 한국자원식물학회지
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• 제24권2호
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• pp.236-242
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• 2011

제주산 녹차 및 발효 정도를 20%, 50%, 80%로 달리한 3종류의 발효차를 $90^{\circ}C$ 열수에 추출하여 추출물의 항산화능, 지질과산화 억제능 그리고 혈관내피세포(CPAE)를 이용하여 산화스트레스에 대한 세포 보호효과를 조사하였다. 녹차나 다른 발효차에 비해 20% 발효차에서 항산화능을 평가하는 DPPH 소거능이 가장 우수한 것으로 나타났다. 20% 발효차의 80 ${\mu}g/mL$ 처리 시 50 ${\mu}M$ 농도의 EGCG 처리와 거의 유사한 free radical 소거율을 보였다. 녹차와 3종류의 발효차 모두 LDL 산화를 억제하여 우수한 지질과 산화 억제능을 보였으나 특히 저농도인 40 ${\mu}g/mL$ 처리 시에 녹차와 20% 발효차의 경우 다른 발효차에 비해 25~30% 정도 더 LDL의 산화가 억제 되어 50 ${\mu}M$/mL EGCG 처리 시와 거의 동일한 수준의 지질과산화 억제 효과를 보였다. CPAE 세포에 녹차 및 3종류의 발효차 추출물을 처리한 실험에서 전혀 추출물을 처리하지 않은 세포에 비해 세포활성이 40~60% 증가하였다. 특히 세포에 1 mM 과산화수소를 처리하여 산화스트레스를 유발한 실험에서 녹차 및 발효차 추출물의 처리가 세포의 산화스트레스에 대한 보호효과를 나타내는 것을 알 수 있었다. 이상의 결과들은 녹차 및 발효차 추출물이 세포 내 free radical을 제거함으로써 산화스트레스에 대한 세포 보호효과에 중요한 기능 중의 하나로 작용한 것과 20% 발효차가 다른 발효차에 비해 우수한 항산화기능을 나타낸다는 것을 보여주었다.

• 대한수학회지
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• 제55권3호
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• pp.553-574
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• 2018

In this paper, we study harmonic maps and biharmonic maps on the principal G-bundle in Kobayashi and Nomizu and also the warped product $P=M{\times}_fF$ for a $C^{\infty}$(M) function f on M studied by Bishop and O'Neill, and Ejiri.

• 대한수학회보
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• 제50권2호
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• pp.589-599
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• 2013

In this paper, we propose a sufficient condition for the existence of solutions to general variational inequality problems (GVI(K, F, $g$)). The condition is also necessary when F is a $g-P^M_*$ function. We also investigate the boundedness of the solution set of (GVI(K, F, $g$)). Furthermore, we show that when F is norm-coercive, the general complementarity problems (GCP(K, F, $g$)) has a nonempty compact solution set. Finally, we establish some existence theorems for (GNCP(K, F, $g$)).