바로가기메뉴

본문 바로가기 주메뉴 바로가기

logo

Vol.27 No.4

Aydinoglu, Selin ; Ornek, Bulent Nafi pp.157-169 https://doi.org/https://doi.org/10.7468/jksmeb.2020.27.4.157
초록보기
Abstract

In this paper, we improve a new boundary Schwarz lemma, for analytic functions in the unit disk. For new inequalities, the results of Rogosinski's lemma, Subordinate principle and Jack's lemma were used. Moreover, in a class of analytic functions on the unit disc, assuming the existence of angular limit on the boundary point, the estimations below of the modulus of angular derivative have been obtained.

Amin, Ruhul ; Nayeem, Sk. Md. Abu pp.171-186 https://doi.org/https://doi.org/10.7468/jksmeb.2020.27.4.171
초록보기
Abstract

Long back in 1972, it was shown that the sum of the squares of vertex degrees and the sum of cubes of vertex degrees of a molecular graph both have large correlations with total 𝜋-electron energy of the molecule. Later on, the sum of squares of vertex degrees was named as first Zagreb index and became one of the most studied molecular graph parameter in the field of chemical graph theory. Whereas, the other sum remained almost unnoticed until recently except for a few occasions. Thus it got the name "forgotten" index or F-index. This paper investigates extremal graphs with respect to F-index among the class of bicyclic graphs with n vertices and k pendant vertices, 0 ≤ k ≤ n - 4. As consequences, we obtain the bicyclic graphs with largest and smallest F-indices.

Prasad, Gopi ; Tomar, Anita ; Dimri, Ramesh Chandra ; Bartwal, Ayush pp.187-205 https://doi.org/https://doi.org/10.7468/jksmeb.2020.27.4.187
초록보기
Abstract

In this article, we prove coincidence point theorems for comparable 𝜓-contractive mappings in ordered non-Archimedean fuzzy metric spaces utilizing the recently established concept of 𝓣-comparability and relatively weaker order theoretic variants. With a view to show the usefulness and applicability of this work, we solve the system of ordered Fredholm integral equations as an application. In the process, this presentation generalize and improve some prominent recent results obtained in Mihet [Fuzzy Sets Syst., 159 (6), 739-744, (2008)], Altun and Mihet [ Fixed Point Theory Appl. 2010, 782680, (2010)], Alam and Imdad [Fixed Point Theory, 18(2), 415-432, (2017)] and several others in the settings of partially ordered non-Archimedean fuzzy metric spaces.

초록보기
Abstract

We establish fixed point and multidimensional fixed point results satisfying generalized (𝜓, 𝜃, 𝜑)-contraction on partially ordered non-Archimedean fuzzy metric spaces. By using this result we obtain the solution for periodic boundary value problems and give an example to show the degree of validity of our hypothesis. Our results generalize, extend and modify several well-known results in the literature.

Lee, Chaeyoung ; Wang, Jian ; Jang, Hanbyeol ; Han, Hyunsoo ; Lee, Seongjin ; Lee, Wonjin ; Yang, Kisung ; Kim, Junseok pp.231-249 https://doi.org/https://doi.org/10.7468/jksmeb.2020.27.4.231
초록보기
Abstract

We present an efficient and robust finite difference method for a two-asset jump diffusion model, which is a partial integro-differential equation (PIDE). To speed up a computational time, we compute a matrix so that we can calculate the non-local integral term fast by a simple matrix-vector operation. In addition, we use bilinear interpolation to solve integral term of PIDE. We can obtain more stable value by using the payoff-consistent extrapolation. We provide numerical experiments to demonstrate a performance of the proposed numerical method. The numerical results show the robustness and accuracy of the proposed method.

Cheon, Eun Ju ; Kim, Seon Jeong pp.251-267 https://doi.org/https://doi.org/10.7468/jksmeb.2020.27.4.251
초록보기
Abstract

We classify all semigroups each of which arises as a Weierstrass semigroup at a pair of non-Weierstrass points on a smooth plane curve of degree 5. First we find the candidates of semigroups by computing the dimensions of linear series on the curve. Then, by constructing examples of smooth plane curves of degree 5, we prove that each of the candidates is actually a Weierstrass semigroup at some pair of points on the curve. We need to study the systems of quadratic curves, which cut out the canonical series on the plane curve of degree 5.

Journal of the Korean Society of Mathematical Education Series B: The Pure and Applied Mathematics