• Korean Journal of Mathematics
• /
• v.28 no.2
• /
• pp.205-221
• /
• 2020

Paranormed spaces are important as a generalization of the normed spaces in terms of having more general properties. The aim of this study is to introduce a new paranormed space |𝜙_z|(p) over the paranormed space ℓ(p) using Euler totient means, where p = (p_k) is a bounded sequence of positive real numbers. Besides this, we investigate topological properties and compute the α-, β-, and γ duals of this paranormed space. Finally, we characterize the classes of infinite matrices (|𝜙_z|(p), λ) and (λ, |𝜙_z|(p)), where λ is any given sequence space.

• Honam Mathematical Journal
• /
• v.35 no.1
• /
• pp.101-107
• /
• 2013

The Gamma function ${\Gamma}$ which was first introduced b Euler in 1730 has played a very important role in many branches of mathematics, especially, in the theory of special functions, and has been introduced in most of calculus textbooks. In this note, our major aim is to explain the convergence of the Euler's Gamma function expressed as an improper integral by using some elementary properties and a fundamental axiom holding on the set of real numbers $\mathbb{R}$, in a detailed and instructive manner. A brief history and origin of the Gamma function is also considered.

• Bulletin of the Korean Mathematical Society
• /
• v.61 no.2
• /
• pp.557-584
• /
• 2024

An almost complex torus manifold is a 2n-dimensional compact connected almost complex manifold equipped with an effective action of a real n-dimensional torus Tⁿ ≃ (S¹)ⁿ that has fixed points. For an almost complex torus manifold, there is a labeled directed graph which contains information on weights at the fixed points and isotropy spheres. Let M be a 6-dimensional almost complex torus manifold with Euler number 6. We show that two types of graphs occur for M, and for each type of graph we construct such a manifold M, proving the existence. Using the graphs, we determine the Chern numbers and the Hirzebruch χ_y-genus of M.

• Communications of the Korean Mathematical Society
• /
• v.22 no.4
• /
• pp.609-621
• /
• 2007

Comparison of high Mach number jets using positive schemes and Weighted ENO methods is considered in this paper. The positive scheme introduced by [11, 14] and Weighted ENO [9, 10] have allowed us to simulate very high Mach numbers more than Mach 80. Simulations at high Mach numbers and with radiative cooling are essential for achieving detailed agreement with astrophysical images.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.8 no.1
• /
• pp.27-37
• /
• 2004

The convergence characteristics of preconditioned Euler equations were studied. A perturbation analysis was conducted to understand the behavior of the preconditioned Euler equations. Various speed flows in a two-dimensional channel with a 10％ circular arc in the middle of the channel were calculated. Roe's FDS scheme was used for spatial discretization and the LU-SGS scheme was used for time integration. It is shown that the convergence characteristics of pressure and velocity were maintained regardless of the Mach numbers but that the convergence characteristics of temperature were strongly related to the Mach number and became worse as the Mach number decreased. The perturbation analysis well explained the trend of the convergence characteristics and showed that the convergence characteristics are strongly related with the behavior o( the Preconditioning matrix.

• Journal of the Society of Naval Architects of Korea
• /
• v.31 no.1
• /
• pp.63-70
• /
• 1994

The three-dimensional incompressible clavier-Stokes equations are solved to simulate the flow field around a Wigley model with free-surface. The IAF(Implicit Approximate Factorization) method is used to show a good success in reducing the computing time. The CPU time is almost an half of that if the IAF method were used. The present method adopts the local linearization and Euler implicit scheme without the pressure-gradient terms for the artificial viscosity. Calculations are carried out at the Reynolds number of $10^6$ and the Froude numbers are 0.25, 0.289 and 0.316. For the approximations of turbulence, the Baldwin-Lomax model is used. The resulting free-surface wave configurations and the velocity vectors are compared with those by the explicit method and experiments.

• Journal of the Korean Mathematical Society
• /
• v.45 no.2
• /
• pp.435-453
• /
• 2008

In this paper, by using q-deformed bosonic p-adic integral, we give $\lambda$-Bernoulli numbers and polynomials, we prove Witt's type formula of $\lambda$-Bernoulli polynomials and Gauss multiplicative formula for $\lambda$-Bernoulli polynomials. By using derivative operator to the generating functions of $\lambda$-Bernoulli polynomials and generalized $\lambda$-Bernoulli numbers, we give Hurwitz type $\lambda$-zeta functions and Dirichlet's type $\lambda$-L-functions; which are interpolated $\lambda$-Bernoulli polynomials and generalized $\lambda$-Bernoulli numbers, respectively. We give generating function of $\lambda$-Bernoulli numbers with order r. By using Mellin transforms to their function, we prove relations between multiply zeta function and $\lambda$-Bernoulli polynomials and ordinary Bernoulli numbers of order r and $\lambda$-Bernoulli numbers, respectively. We also study on $\lambda$-Bernoulli numbers and polynomials in the space of locally constant. Moreover, we define $\lambda$-partial zeta function and interpolation function.

• Honam Mathematical Journal
• /
• v.43 no.4
• /
• pp.741-749
• /
• 2021

A variant of up-down posets described below and the number of their linear extensions were studied. We obtained the exponential generating functions which showed that how they are related to the Euler's up-down numbers.

• Journal of the Chungcheong Mathematical Society
• /
• v.26 no.4
• /
• pp.769-780
• /
• 2013

Motivated essentially by their potential for applications in a wide range of mathematical and physical problems, the log-sine and log-cosine integrals have been evaluated, in the existing literature on the subject, in many different ways. Very recently, Choi [6] presented explicit evaluations of some families of log-sine and log-cosine integrals by making use of the familiar Beta function. In the present sequel to the investigation [6], we evaluate the log-sine and log-cosine integrals involved in more complicated integrands than those in [6], by also using the Beta function.

• Bulletin of the Korean Mathematical Society
• /
• v.52 no.2
• /
• pp.467-481
• /
• 2015

Choi and Park introduced an invariant of a finite simple graph, called signed a-number, arising from computing certain topological invariants of some specific kinds of real toric manifolds. They also found the signed a-numbers of path graphs, cycle graphs, complete graphs, and star graphs. We introduce a signed a-polynomial which is a generalization of the signed a-number and gives a-, b-, and c-numbers. The signed a-polynomial of a graph G is related to the $Poincar\acute{e}$ polynomial $P_{M(G)}(z)$, which is the generating function for the Betti numbers of the real toric manifold M(G). We give the generating functions for the signed a-polynomials of not only path graphs, cycle graphs, complete graphs, and star graphs, but also complete bipartite graphs and complete multipartite graphs. As a consequence, we find the Euler characteristic number and the Betti numbers of the real toric manifold M(G) for complete multipartite graphs G.