• 대한수학회지
• /
• 제42권5호
• /
• pp.893-912
• /
• 2005

We discuss a certain geometric property $X_{{\theta},{\gamma}}$ of dual algebras generated by a polynomially bounded operator and property ($\mathbb{A}_{N_0,N_0}$; these are central to the study of $N_{0}\timesN_{0}$-systems of simultaneous equations of weak$^{*}$-continuous linear functionals on a dual algebra. In particular, we prove that if T $\in$ $\mathbb{A}$$^{M}$ satisfies a certain sequential property, then T $\in$ $\mathbb{A}^{M}_{N_0}(H) if and only if the algebra $A_{T}$ has property $X_{0, 1/M}$, which is an improvement of Li-Pearcy theorem in [8].

• 대한수학회논문집
• /
• 제39권2호
• /
• pp.313-329
• /
• 2024

An (additive) commutative monoid is called atomic if every given non-invertible element can be written as a sum of atoms (i.e., irreducible elements), in which case, such a sum is called a factorization of the given element. The number of atoms (counting repetitions) in the corresponding sum is called the length of the factorization. Following Geroldinger and Zhong, we say that an atomic monoid M is a length-finite factorization monoid if each b ∈ M has only finitely many factorizations of any prescribed length. An additive submonoid of ℝ_≥0 is called a positive monoid. Factorizations in positive monoids have been actively studied in recent years. The main purpose of this paper is to give a better understanding of the non-unique factorization phenomenon in positive monoids through the lens of the length-finite factorization property. To do so, we identify a large class of positive monoids which satisfy the length-finite factorization property. Then we compare the length-finite factorization property to the bounded and the finite factorization properties, which are two properties that have been systematically investigated for more than thirty years.

• Korean Journal of Mathematics
• /
• 제13권1호
• /
• pp.91-101
• /
• 2005

In this paper, we give the notion of the D-shadowing property, D-inverse shadowing property for dynamical systems. and investigate the density of D-shadowing dynamical systems and the D-inverse shadowing dynamical systems. Moreover we study some relationships between the D-shadowing property and other dynamical properties such as expansivity and topological stability.

• 전기학회논문지P
• /
• 제60권3호
• /
• pp.126-132
• /
• 2011

A conventional LDO(Low Dropout Regulator) uses one OPAMP and one signal path. This means that OPAMP's DC Gain and Bandwidth can't optimize simultaneously within usable power. This also appears that regulation property and settling time of LDO can't improve at the same time. Based on this idea, a proposed LDO uses two OPAMP and has two signal path. To improve regulation property, OPAMP where is used in the path which qualities DC gain on a large scale, bandwidth designed narrowly. To improve settling time, OPAMP where is used in the path which qualities DC gain small, bandwidth designed widely. A designed LDO used 0.5um 1P2M process and provided 200mA of output current. A line regulation and load regulation is 12.6mV/V, 0.25mV/mA, respectively. And measured settling time is 1.5us in 5V supply voltage.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1999년도 봄 학술발표회 논문집
• /
• pp.137-144
• /
• 1999

The finite element method was adopted to find out the natural frequencies of a sinusoidally tapered beam with simply supported boundary conditions. The parameters considered in the numerical analysis are the taper parameter, $\alpha$ ($\alpha$=0.0, 0.1, ~ , 2.0) and the sectional property parameters, m and n [(m, n):(0, 2), (1, 3), (2, 4)]. It is generally known that the results of the numerical analysis corresponding to each pair of sectional property parameters, (m, n) are represented by second order polynominals of $\alpha$ . The coefficients of a in the polynominals are determined by using the regression technique, which reveals small m in most cases of given sectional property parameters (m, n).

• 대한수학회보
• /
• 제33권3호
• /
• pp.385-392
• /
• 1996

Smale [16] posed the following question; is having an attracting periodic orbit a generic property for diffeomorphisms of two-sphere $S^2\ulcorner$(A generic property of $f \in Diff(M)$ is one that is true for a Baire set in Diff(M)). Mane[5] and Plykin[13] had an positive answer for Axiom A diffeomorphisms of $S^2$. To explain our theorem, we begin by briefly recalling stability conjecture posed by palis and smale.

• 대한수학회보
• /
• 제40권3호
• /
• pp.503-508
• /
• 2003

We prove that every M-ideal is strongly proximinal and that, for any Banach space X, $K(X,\;c_0)$ is an M-ideal in $L(X,\;\ell^{\infty})$.

• 대한수학회논문집
• /
• 제18권3호
• /
• pp.481-484
• /
• 2003

We will show that if U is a Bergman ball E($\alpha;\;\delta$) in $B_n\;\subset\;{\mathbb{C}_n}$ and if U has M-harmonic volume mean value property at a for all M-harmonic functions f on $\={U} $, then U must be a ball centered at the origin with $\alpha\;=\;0$.

• 호남수학학술지
• /
• 제28권1호
• /
• pp.141-164
• /
• 2006

Let $G=O(2){\times}O(2){\times}O(2)$ and let $M^4$ be a closed G-invariant minimal hypersurface with constant scalar curvature in $S^5$. In this paper, we prove a property on $M^4$.

• Kyungpook Mathematical Journal
• /
• 제49권3호
• /
• pp.411-418
• /
• 2009

In this paper we introduce the notions of strict persistence and weakly strict persistence which are stronger than those of persistence and weak persistence, respectively, and study their relations with shadowing property. In particular, we show that the weakly strict persistence and the weak inverse shadowing property are locally generic in Z(M).