http://journals.math.tku.edu.tw/index.php/TKJM/issue/feedTamkang Journal of Mathematics2018-09-04T13:58:07+08:00Editorial Officeeo-tkjm@mail2.tku.edu.twOpen Journal Systems<strong>Welcome to Tamkang Journal of Mathematics </strong><br /><br /><strong>~Hot News~ </strong><br /><br /><strong>Tamkang Journal of Mathematics(TKJM) is included in Emerging Sources Citation Index (ESCI)</strong> <br /><br /><img src="/public/site/images/admin/201709_ESCI收錄TKJM畫面.jpg" alt="" width="450" height="247" /><br /><br /><br /><strong>Aims and Scope</strong><br /><div>To promote research interactions between local and overseas researchers, the Department has been publishing an international mathematics journal, the Tamkang Journal of Mathematics. The journal started as a biannual journal in 1970 and is devoted to high-quality original research papers in pure and applied mathematics. In 1985 it has become a quarterly journal.</div>http://journals.math.tku.edu.tw/index.php/TKJM/article/view/2169Normal edge-transitive and \frac{1}{2}-arc-transitive cayley graphs on non-abelian groups of odd order 3pq, p and q are primes2018-09-04T13:58:07+08:00Ali Reza Ashrafiashrafi@kashanu.ac.irBijan Soleimanibijan_s59@yahoo.comSuppose $p$ and $q$ are odd prime numbers. In this paper, the connected Cayley graph of groups of order $3pq$, for primes $p$ and $q$, are investigated and all connected normal $\frac{1}{2}-$arc-transitive Cayley graphs of group of these orders will be classified.2018-09-30T00:00:00+08:00http://journals.math.tku.edu.tw/index.php/TKJM/article/view/2358Factorized enhancement of Copson's inequality2018-09-04T13:58:07+08:00Atanu Mannaatanuiitkgp86@gmail.comThis paper dealt with the factorized enhancement of Copson's inequality and improves one of the results given by Leindler.2018-09-30T00:00:00+08:00http://journals.math.tku.edu.tw/index.php/TKJM/article/view/2506Certain results on N(k)-contact metric manifolds2018-09-04T13:58:07+08:00Uday Chand Deuc_de@yahoo.comIn the present paper we study contact metric manifolds whose characteristic vector field $\xi$ belonging to the $k$-nullity distribution. First we consider concircularly pseudosymmetric $N(k)$-contact metric manifolds of dimension $(2n+1)$. Beside these, we consider Ricci solitons and gradient Ricci solitons on three dimensional $N(k)$-contact metric manifolds. As a consequence we obtain several results. Finally, an example is given.2018-09-30T00:00:00+08:00http://journals.math.tku.edu.tw/index.php/TKJM/article/view/2613Constant curvature surfaces in a pseudo-isotropic space2018-09-04T13:58:07+08:00Muhittin Evren Aydinmeaydin@firat.edu.trIn this study, we deal with the local structure of curves and surfaces immersed in a pseudo-isotropic space $\mathbb{I}_{p}^{3}$ that is a particular Cayley-Klein space. We provide the formulas of curvature, torsion and Frenet trihedron for spacelike and timelike curves, respectively. The causal character of all admissible surfaces in $\mathbb{I}_{p}^{3}$ has to be timelike up to its absolute. We introduce the formulas of Gaussian and mean curvature for timelike surfaces in $\mathbb{I}_{p}^{3}$. As applications, we describe the surfaces of revolution which are the orbits of a plane curve under a hyperbolic rotation with constant Gaussian and mean curvature.2018-09-30T00:00:00+08:00http://journals.math.tku.edu.tw/index.php/TKJM/article/view/2638Optimal casorati inequalities on bi-slant submanifolds of generalized sasakian space forms2018-09-04T13:58:07+08:00Aliya Naaz Siddiquialiyanaazsiddiqui9@gmail.comIn this paper, we use T Oprea's optimization method to establish some optimal Casorati inequalities, which involve the normalized scalar curvature for bi-slant submanifolds of generalized Sasakian space forms. In the continuation, we show that in both cases, the equalities hold if and only if submanifolds are invariantly quasi-umbilical.2018-09-30T00:00:00+08:00http://journals.math.tku.edu.tw/index.php/TKJM/article/view/2690Inequalities of Jensen's type for generalized k-g-fractional integrals2018-09-04T13:58:07+08:00Silvestru Sever DragomirSever.Dragomir@vu.edu.auIn this paper we establish some inequalities of Jensen and Hermite-Hadamard type for the $k$-$g$-fractional integrals of convex functions defined an interval $\left[ a,b\right] $. Some examples for the\textit{\ generalized} \textit{left-} and \textit{right-sided Riemann-Liouville fractional integrals} of a function $f$ with respect to another function $g$ on $\left[ a,b\right] $ and for classical Riemann-Liouville fractional integrals are also given.2018-09-30T00:00:00+08:00