Abstract : In this paper we present a full circle approximation method using parametric polynomial curves with algebraic coefficients which are curvature continuous at both endpoints. Our method yields the $n$-th degree parametric polynomial curves which have a total number of $2n$ contacts with the full circle at both endpoints and the midpoint. The parametric polynomial approximants have algebraic coefficients involving rational numbers and radicals for degree higher than four. We obtain the exact Hausdorff distances between the circle and the approximation curves.
Abstract : In the present paper, a Riemannian submersion $\pi$ between Riemannian manifolds such that the total space of $\pi$ endowed with a torse-forming vector field $\nu$ is studied. Some remarkable results of such a submersion whose total space is Ricci soliton are given. Moreover, some characterizations about any fiber of $\pi$ or the base manifold $B$ to be an almost quasi-Einstein are obtained.
Abstract : Let $\mathcal{A}$ be a unital Banach $*$-algebra and $\mathcal{M}$ be a unital $*$-$\mathcal{A}$-bimodule. If $W$ is a left separating point of $\mathcal{M}$, we show that every $*$-derivable mapping at $W$ is a Jordan derivation, and every $*$-left derivable mapping at $W$ is a Jordan left derivation under the condition $W \mathcal{A}=\mathcal{A}W$. Moreover we give a complete description of linear mappings $\delta$ and $\tau$ from $\mathcal{A}$ into $\mathcal{M}$ satisfying $\delta(A)B^*+A\tau(B)^*=0$ for any $A, B\in \mathcal{A}$ with $AB^*=0$ or $\delta(A)\circ B^*+A\circ\tau(B)^*=0$ for any $A, B\in \mathcal{A}$ with $A\circ B^*=0$, where $A\circ B=AB+BA$ is the Jordan product.
Abstract : A class of systems of Caputo fractional differential equations with integral boundary conditions is considered. A numerical method based on a finite difference scheme on a uniform mesh is proposed. Supremum norm is used to derive an error estimate which is of order $\kappa-1$, $1
Abstract : The object of the present paper is to study the properties of conharmonically flat $(LCS)_n$-manifold, special weakly Ricci symmetric and generalized Ricci recurrent $(LCS)_n$-manifold. The existence of such a manifold is ensured by non-trivial example.
Abstract : This paper attempts to investigate a new subfamily \linebreak $\mathcal{ST}_{\vartheta ,\sigma}\left( \alpha ,\beta ,\gamma ,\mu \right) $ of spirallike functions endowed with Mittag-Leffler and Wright functions. The paper further investigates sharp coefficient bounds for functions that belong to this class.
Abstract : In this paper, some estimations will be given for the analytic functions belonging to the class $\mathcal{R}\left( \alpha \right) $. In these estimations, an upper bound and a lower bound will be determined for the first coefficient of the expansion of the analytic function $h(z)$ and the modulus of the angular derivative of the function $\frac{zh^{\prime }(z)}{ h(z)}$, respectively. Also, the relationship between the coefficients of the analytical function $h(z)$ and the derivative mentioned above will be shown.
Abstract : In this erratum, we correct a mistake in the proof of Proposition 2.7. In fact the equivalence $(3)\Longleftarrow (4)$ ``$R$ is a quasi-regular ring if and only if $R$ is a reduced ring and every principal ideal contained in $Z(R)$ is a 0-ideal'' does not hold as we only have $Rx\subseteq O(S)$.
Abstract : For given non-negative real numbers $\alpha_k$ with $ \sum_{k=1}^{m}\alpha_k =1$ and normalized analytic functions $f_k$, $k=1,\dotsc,m$, defined on the open unit disc, let the functions $F$ and $F_n$ be defined by $ F(z):=\sum_{k=1}^{m}\alpha_k f_k (z)$, and $F_{n}(z):=n^{-1}\sum_{j=0}^{n-1} e^{-2j\pi i/n} F(e^{2j\pi i/n} z)$. This paper studies the functions $f_k$ satisfying the subordination $zf'_{k} (z)/F_{n} (z) \prec h(z)$, where the function $h$ is a convex univalent function with positive real part. We also consider the analogues of the classes of starlike functions with respect to symmetric, conjugate, and symmetric conjugate points. Inclusion and convolution results are proved for these and related classes. Our classes generalize several well-known classes and the connections with the previous works are indicated.
Abstract : In this article we relate the six Pr\"{u}fer conditions with the EM conditions. We use the EM-conditions to prove some cases of equivalence of the six Pr\"{u}fer conditions. We also use the Pr\"{u}fer conditions to answer some open problems concerning EM-rings.
Guodong Hua
Commun. Korean Math. Soc. 2023; 38(2): 319-330
https://doi.org/10.4134/CKMS.c210366
Asmaa Orabi Mohammed, Medhat Ahmed Rakha, Arjun K. Rathie
Commun. Korean Math. Soc. 2023; 38(3): 807-819
https://doi.org/10.4134/CKMS.c220217
Hieu Van Ha, Duong Quang Hoa, Vu Anh Le
Commun. Korean Math. Soc. 2022; 37(4): 1181-1197
https://doi.org/10.4134/CKMS.c210308
Ejaz Sabir Lone, Pankaj Pandey
Commun. Korean Math. Soc. 2023; 38(1): 223-234
https://doi.org/10.4134/CKMS.c220011
Ali Benhissi, Abdelamir Dabbabi
Commun. Korean Math. Soc. 2024; 39(1): 71-77
https://doi.org/10.4134/CKMS.c230111
Hyojun An, Hyungjin Huh
Commun. Korean Math. Soc. 2023; 38(4): 1091-1100
https://doi.org/10.4134/CKMS.c220362
Md. Adud, BIKASH CHAKRABORTY
Commun. Korean Math. Soc. 2024; 39(1): 117-125
https://doi.org/10.4134/CKMS.c230016
Souad DAKIR, Hajar EL MIR, Abdellah MAMOUNI
Commun. Korean Math. Soc. 2024; 39(1): 1-10
https://doi.org/10.4134/CKMS.c230052
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