• 대한수학회논문집
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• 제39권2호
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• pp.437-460
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• 2024

In this paper we present the weighted shift operators having the property of moment infinite divisibility. We first review the monotone theory and conditional positive definiteness. Next, we study the infinite divisibility of sequences. A sequence of real numbers γ is said to be infinitely divisible if for any p > 0, the sequence γ^p = {γ^p_n}^∞_n=0 is positive definite. For sequences α = {α_n}^∞_n=0 of positive real numbers, we consider the weighted shift operators W_α. It is also known that W_α is moment infinitely divisible if and only if the sequences {γ_n}^∞_n=0 and {γ_n+1}^∞_n=0 of W_α are infinitely divisible. Here γ is the moment sequence associated with α. We use conditional positive definiteness to establish a new criterion for moment infinite divisibility of W_α, which only requires infinite divisibility of the sequence {γ_n}^∞_n=0. Finally, we consider some examples and properties of weighted shift operators having the property of (k, 0)-CPD; that is, the moment matrix M_γ(n, k) is CPD for any n ≥ 0.

• 응용통계연구
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• 제22권5호
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• pp.1103-1113
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• 2009

피보나치수열의 첫 숫자수열이 벤포드법칙을 따름은 알려진 사실이다. 이러한 피보나치수열을 확장하여 임의의 두개의 자연수를 정하고 재귀식 $a_{n+2}=a_{n+1}+a_n$을 만족하는 수열을 만들었을 때 이 수열의 첫 숫자수열이 벤포드법칙을 만족하는 지를 확인하고 이러한 수열의 첫 숫자수열의 구조를 탐색적 자료분석의 입장에서 살펴보았다.

• Journal of applied mathematics & informatics
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• 제4권1호
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• pp.147-166
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• 1997

The convergence of the power sequence of an $n{\times}n$ fuzzy matrix has been studied. Some theoretical necessary and sufficient con-ditions have been established for the power sequence to be convergent generally. Furthermore as one of our main concerns the convergence index was studied in detail especially for some special types of Boolean matrices. Also it has been established that the convergence index is bounded by $(n-1)^2+1$ from above for an arbitrary $n{\times}n$ fuzzy matrix if its power sequence converges. Our method is concentrated on the limit behavior of the power se-quence. It helped us to make our proofs be simpler and more direct that those in pure algebraic methods.

• Journal of applied mathematics & informatics
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• 제4권2호
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• pp.513-528
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• 1997

A sort sequence $S_n$ is a sequence of all unordered pairs of indices in $I_n\;=\;{1,\;2,v...,\;n}$. With a sort sequence Sn we assicuate a sorting algorithm ($AS_n$) to sort input set $X\;=\;{x_1,\;x_2,\;...,\;x_n}$ as follows. An execution of the algorithm performs pairwise comparisons of elements in the input set X as defined by the sort sequence $S_n$, except that the comparisons whose outcomes can be inferred from the outcomes of the previous comparisons are not performed. Let $X(S_n)$ denote the acverage number of comparisons required by the algorithm $AS_n$ assuming all input orderings are equally likely. Let $X^{\ast}(n)\;and\;X^{\circ}(n)$ denote the minimum and maximum value respectively of $X(S_n)$ over all sort sequences $S_n$. Exact determination of $X^{\ast}(n),\;X^{\circ}(n)$ and associated extremal sort sequenes seems difficult. Here, we obtain bounds on $X^{\ast}(n)\;and\;X^{\circ}(n)$.

• 한국수학사학회지
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• 제21권4호
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• pp.87-104
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• 2008

본 연구에서는 유명한 피보나치 수열을 일반화하는 g-피보나치 수열 $\{g_n\}$={a, b, a+b, a+2b, 2a+3b, 3a+5b,...}의 여러 가지 성질과 특성을 조사한다. 특히, g-피보나치 수열의 합에 관한 항등식과 제 n항 $g_n$(비네의 공식의 일반화)을 구체적으로 구한다. 또한 피보나치 수열에 관한 카타란의 항등식의 일반화된 항등식과 A. Tagiuri의 항등식을 구하고 $g_n$과 파스칼 삼각형과의 관계식과 g-피보나치 수 $g_n$이 얼마나 빨리 커지는가를 조사한다. 아울러 g-피보나치 수열의 초항과 둘째 항이 서로 소일 때 연속하는 두 항은 서로 소이며, 연속하는 두 항의 비율 $\{\frac{g_{n+1}}{g_n}\}$은 황금비 $\frac{1+\sqrt5}2$ 수렴함을 밝히고자한다.

• 대한수학회보
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• 제36권4호
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• pp.747-754
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• 1999

We compute the mod p homology of the double loop space of Sp(n)/U(n) by the Serre spectral sequence and the Eilenberg-Moore spectral sequence with the homology operations.

• 대한수학회보
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• 제40권2호
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• pp.281-288
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• 2003

We compute the mod p homology of the double loop space of 50(2n)/U(n) by the Serre spectral sequence of Hopf algebras. We also obtain the torsion information of the integral homology.

• Journal of applied mathematics & informatics
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• 제19권1_2호
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• pp.191-201
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• 2005

In this paper, the existence of periodic positive solution and the attractivity are investigated for the rational recursive sequence $x_{n+1} = (A + ax_{n_k})/(b + x{n-l})$, where A, a and b are real numbers, k and l are nonnegative integer numbers.

• 대한수학회보
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• 제59권6호
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• pp.1349-1357
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• 2022

Let 𝒜 = (A_n)_n≥0 be an increasing sequence of rings. We say that 𝓘 = (I_n)_n≥0 is an associated sequence of ideals of 𝒜 if I₀ = A₀ and for each n ≥ 1, I_n is an ideal of A_n contained in I_n+1. We define the polynomial ring and the power series ring as follows: $I[X]\, = \,\{\, f \,=\, {\sum}_{i=0}^{n}a_iX^i\,{\in}\,A[X]\,:\,n\,{\in}\,\mathbb{N},\,a_i\,{\in}\,I_i \,\}$ and $I[[X]]\, = \,\{\, f \,=\, {\sum}_{i=0}^{+{\infty}}a_iX^i\,{\in}\,A[[X]]\,:\,a_i\,{\in}\,I_i \,\}$. In this paper we study the Noetherian and the SFT properties of these rings and their consequences.

• 호남수학학술지
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• 제40권1호
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• pp.199-210
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• 2018

In this paper we obtain some formulae for several sums of generalized Fibonacci numbers $U_n$ and generalized Lucas numbers $V_n$ and their dual forms $G_n$ and $H_n$ by using extensions of an interesting identity by A. R. Amini for Fibonacci numbers to these four kinds of generalizations and their first and second derivatives.