• Journal of applied mathematics & informatics
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• 제37권5_6호
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• pp.481-489
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• 2019

In this manuscript, we provide some new results with short proofs for the existence of Picard-Jungck operators in the framework of generalized metric spaces using $C_G$-simulation functions. An example is also provided to illustrate the usability of the results.

• 대한수학회논문집
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• 제36권1호
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• pp.165-171
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• 2021

The purpose of this paper is to investigate the geometry of complete gradient Yamabe soliton (Mn, g, f, λ) with constant scalar curvature admitting a non-homothetic conformal vector field V leaving the potential vector field invariant. We show that in such manifolds the potential function f is constant and the scalar curvature of g is determined by its soliton scalar. Considering the locally conformally flat case and conformal vector field V, without constant scalar curvature assumption, we show that g has constant curvature and determines the potential function f explicitly.

• 융합보안논문지
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• 제19권1호
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• pp.3-10
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• 2019

5G 네트워크는 초고속, 초연결, 초저지연이라는 요구를 구현하기 위해 다양한 ICT 기술들을 접목한 차세대 융합 네트워크로서, 이전 세대 이동통신 네트워크의 보안취약점을 해결하기 위해 다양한 노력들이 시도되었다. 그러나 현재까지 발표된 표준화 규격들에는 USIM 탈취 및 복제, 메시지 재전송 공격, 경쟁조건 공격 등의 보안취약점이 여전히 존재한다. 이러한 문제를 해결하기 위해, 본 논문에서는 물리적 복제방지 기능인 PUF 기술을 적용한 새로운 5G 인증 및 키합의 프로토콜을 제시한다. 제시된 PUF 기반의 인증 및 키합의 프로토콜은 특정 입력값에 대해 장치별로 고유하게 생성되는 응답값과 해시함수를 이용하여 현재까지 식별된 보안취약점을 개선한다. 이러한 접근 방법은 보안성이 중요하게 요구되는 영역에서 5G 네트워크를 활용할 경우, 저렴한 PUF 회로의 추가를 통해 강력한 화이트리스트 정책을 구현할 수 있게 해 준다. 또한 기존 프로토콜에 추가적인 암호 알고리즘을 적용하지 않기 때문에 연산 비용 증가나 인증 파라미터 저장 공간 증가의 부담도 상대적으로 적다.

• BMB Reports
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• 제34권2호
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• pp.95-101
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• 2001

Tissue transglutaminase (TGII, $G{\alpha}h$) belongs to a family of enzymes which catalyze post-translational modification of proteins by forming isopeptides via $Ca^{2+}$-dependent reaction. Although TGII-mediated formation of isopeptides has been implicated to play a role in a variety of cellular processes, the physiological function of TGII remains unclear. In addition to this Tease activity, TGII is a guanosine triphosphatase (GTPase) which binds and hydrolyzes GTP It is now well recognized that the GTPase action of TGII regulates a receptor-mediated transmembrane signaling, functioning as a signal transducer of the receptor. This TGII function signifies that TGII is a new class of GTP-binding regulatory protein (G-protein) that differs from "Classical" heterotrimeric G-proteins. Regulation of enzyme is an important biological process for maintaining cell integrity. This review summarizes the recent development in regulation of TGII that may help for the better understanding of this unique enzyme. Since activation and inactivation of GTPase of TGII are similar to the heterotrimeric G-proteins, the regulation of heterotrimeric G-protein in the transmembrane signaling is also discussed.

• 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, $g$)).

• Korean Journal of Mathematics
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• 제25권2호
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• pp.215-227
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• 2017

Let D be an integral domain with quotient field K, X be an indeterminate over D, K[X] be the polynomial ring over K, and $R=\{f{\in}K[X]{\mid}f(0){\in}D\}$; so R is a subring of K[X] containing D[X]. For $f=a_0+a_1X+{\cdots}+a_nX^n{\in}R$, let C(f) be the ideal of R generated by $a_0$, $a_1X$, ${\ldots}$, $a_nX^n$ and $N(H)=\{g{\in}R{\mid}C(g)_{\upsilon}=R\}$. In this paper, we study two rings $R_{N(H)}$ and $Kr(R,{\upsilon})=\{{\frac{f}{g}}{\mid}f,g{\in}R,\;g{\neq}0,{\text{ and }}C(f){\subseteq}C(g)_{\upsilon}\}$. We then use these two rings to give some examples which show that the results of [4] are the best generalizations of Nagata rings and Kronecker function rings to graded integral domains.

• 대한수학회지
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• 제43권2호
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• pp.311-322
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• 2006

For the Briot-Bouquet differential equations of the form given in [1] $${{\mu}(z)+\frac {z{\mu}'(z)}{z\frac {f'(z)}{f(z)}\[\alpha{\mu}(z)+\beta]}=g(z)$$ we can reduce them to $${{\mu}(z)+F(z)\frac {v'(z)}{v(z)}=h(z)$$ where $$v(z)=\alpha{\mu}(z)+\beta,\;h(z)={\alpha}g(z)+\beta\;and\;F(z)=f(z)/f'(z)$$. In this paper we are going to give conditions in order that if u and v satisfy, respectively, the equations (1) $${{\mu}(z)+F(z)\frac {v'(z)}{v(z)}=h(z)$$, $${{\mu}(z)+G(z)\frac {v'(z)}{v(z)}=g(z)$$ with certain conditions on the functions F and G applying the concept of strong subordination $g\;\prec\;\prec\;h$ given in [2] by the author, implies that $v\;\prec\;{\mu},\;where\;\prec$ indicates subordination.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제26권1호
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• pp.49-66
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• 2022

The G-Euler process has been proposed to overcome the difficulties of the calculation of the exponential function of the Jacobian. It is an explicit method that uses the exponential function of the scalar skew-symmetric matrix. We define the moving shapes of true solutions and the moving shapes of numerical solutions. It is discussed whether the moving shape of the numerical solution matches the moving shape of the true solution. The match rates of these two kinds of moving shapes are sequentially calculated by the G-Euler process without using the true solution. It is shown that the closer the minimum match rate is to 100%, the more closely the numerical solutions follow the true solutions to the end. The minimum match rate indicates the reliability of the numerical solution calculated by the G-Euler process. The graphs of the Lorenz system in Perko [1] are different from those drawn by the G-Euler process. By the way, there is no basis for claiming that the Perko's graphs are reliable.

• 대한조선학회지
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• 제19권2호
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• pp.33-39
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• 1982

It is one of the basic problems of naval architecture and ocean engineering how to describe the wave kinematics normally under the assumption of an ideal fluid. At present, there are many wave theories available for design purposes. These can be classified into two groups: One is the analytic theory and the other is the numerical theory. This paper briefly introduces the stream function method of R.G. Dean which belongs to the latter group and shows its numerical evaluations exemplified for two cases: One is applied to observed waves and the other is for design waves. In the former case, the wave profiles are calculated by the stream function method and compared with those of the observed waves and also with the results of R.G. Dean. They show good agreement. In the latter case, the wave kinematics and wave loads on a column of diameter 1m are calculated by the stream function method and these are compared with those resulted from the 5th-order gravity wave theory. As a result of comparison the values by the stream function method are slightly larger than those by the 5th-order gravity wave theory but the difference are negligible. From this it is concluded that the stream function method is very useful. And as characteristics of the numerical theories, the stream function method of R.G. Dean can be easily extended to the higher order terms and can include easily the current velocity and the pressure distribution on the free surface. In addition, when the data of observed wave profile are given, this method can reproduced the observed wave profile as closely as possible so that this method seems to describe the ocean wave more realistically. And from standpoint of a mathematical principle the stream function method exactly satisfies the kinematic free-surface boundary condition.

• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.491-495
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• 2006

Methanol extracts of fruits of 67 plants were screened for in vivo antifungal activity against Magnaporthe grisea, Corticium sasaki, Botrytis cinerea, Phytophthora infestans, Puccinia recondita, and Blumeria graminis f. sp. hordei. Among them, 13 plant extracts ($3,000\;{\mu}g/ml$) showed more than 90% disease-control efficacy against at least one of six plant diseases. Specifically, the extracts of Aleurites fordii, Angelica dahurica, Camellia japonica, Chamaecyparis pisifera, Pittosporum tobira, and Styrax japonica controlled more than 90% of the development of rice blast at $1,000{\mu}g/ml$. Extracts of both S. japonica and A. dahurica fruits at $333{\mu}g/ml$ concentration displayed strong antifungal activity against M. grisea on rice seedlings.