• 터널과지하공간
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• 제24권1호
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• pp.81-88
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• 2014

Hoek-Brown 파괴함수를 적용하여 암반구조물의 안정성 분석을 수행하는 경우 암반의 강도를 내부마찰각과 점착력을 이용하여 평가해야하는 경우가 있다. 이러한 경우 ${\sigma}_1-{\sigma}_3$ 관계로 표시된 본래의 Hoek-Brown 함수는 수직응력 (${\sigma}$)과 전단응력 (${\tau}$) 관계인 Mohr 파괴포락선으로 변환되어야 한다. 이 연구에서는 Hoek-Brown 파괴함수의 Mohr 파괴포락선을 구하는 새로운 방법을 제시하였다. 제시한 방법은 Londe (1988)가 제안한 응력무차원화 변환방법을 기초로 하였다. 검증 예제를 통해 새로 유도된 ${\sigma}-{\tau}$ 관계식이 Bray가 유도한 관계식과 정확히 일치한다는 것이 확인되었다.

• 대한수학회논문집
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• 제27권3호
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• pp.441-448
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• 2012

Let R be a prime ring with center Z and characteristic different from two, U a nonzero Lie ideal of R such that $u^2{\in}U$ for all $u{\in}U$ and $d$ be a nonzero (${\sigma}$, ${\tau}$)-derivation of R. We prove the following results: (i) If $[d(u),u]_{{\sigma},{\tau}}$ = 0 or $[d(u),u]_{{\sigma},{\tau}}{\in}C_{{\sigma},{\tau}}$ for all $u{\in}U$, then $U{\subseteq}Z$. (ii) If $a{\in}R$ and $[d(u),a]_{{\sigma},{\tau}}$ = 0 for all $u{\in}U$, then $U{\subseteq}Z$ or $a{\in}Z$. (iii) If $d([u,v])={\pm}[u,v]_{{\sigma},{\tau}}$ for all $u{\in}U$, then $U{\subseteq}Z$.

• 대한수학회논문집
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• 제31권1호
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• pp.101-113
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• 2016

In this article, we considered the stability of the following (${\alpha}$, ${\beta}$, ${\gamma}$)-derivation $${\alpha}D[x,y]={\beta}[D(x),y]+{\gamma}[x,D(y)]$$ and homomorphisms associated to the quadratic type functional equation $$f(kx+y)+f(kx+{\sigma}(y))=2kg(x)+2g(y),\;x,y{\in}A$$, where ${\sigma}$ is an involution of the Lie $C^*$-algebra A and k is a fixed positive integer. The Hyers-Ulam stability on unbounded domains is also studied. Applications of the results for the asymptotic behavior of the generalized quadratic functional equation are provided.

• 대한수학회지
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• 제47권3호
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• pp.495-504
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• 2010

This paper continues a line investigation in [1]. Let A be a K-algebra and M an A/K-bimodule. In [5] Hamaguchi gave a necessary and sufficient condition for gDer(A, M) to be isomorphic to BDer(A, M). The main aim of this paper is to establish similar relationships for generalized ($\sigma$, $\tau$)-derivations.

• Kyungpook Mathematical Journal
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• 제60권2호
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• pp.415-421
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• 2020

In the proof of Theorem 3 on p.253 in [4], both right and left distributivity are assumed simultaneously which makes the proof invalid. We give a corrected proof for this theorem by introducing an extension of Lemma 2.2 in [2].

• Kyungpook Mathematical Journal
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• 제50권3호
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• pp.379-387
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• 2010

In this paper, we present some results concerning orthogonal generalized (${\sigma},{\tau}$)-derivations in semiprime near-rings. These results are a generalization of result of Bresar and Vukman, which are related to a theorem of Posner for the product of two derivations in prime rings.

• Journal of the Korean Data and Information Science Society
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• 제10권1호
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• pp.11-18
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• 1999

To estimate the mean and the variance of a lognormal distribution, Finney (1941) derived the uniformly minimun variance unbiased estimators(UMVUE) in the form of infinite series. However, the conditions ${\sigma}^{2}\;>\;n\;and\;{\sigma}^{2}\;<\;\frac{n}{4}$ for computing $E(\hat{\theta}_{AM})\;and\;E(\hat{\eta}^{2}_{AM})$ are necessary. In this paper, we give an alternative derivation of the UMVUE's.

• 호남수학학술지
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• 제46권1호
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• pp.1-11
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• 2024

In this paper, we introduce the notion of 𝜎-Jordan amenability of Banach algebras and some hereditary are investigated. Similar to Johnson's classic result, we give the notions of 𝜎-Jordan approximate and 𝜎-Jordan virtual diagonals, and find some relations between the existence of them and 𝜎-Jordan amenability.

• 경영과학
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• 제25권1호
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• pp.75-91
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• 2008

Information strategy planning (ISP) pursues alignment of business strategy and IT (Information Technology) strategy as well as derivation of feasible and valuable IT projects. However, conventional ISP methodology hardly obtains the objectives because of its intrinsic shortcomings. Diverse ways are proposed for the improvement of the conventional methodology including, for example, combination of EA (Enterprise Architecture) with ISP. Meanwhile, six-sigma methodology which is characterized by quantification, scientific and systematic approach, customer orientation, process orientation has been gaining considerable attention and extending its application scope continuously. In this paper, an innovative ISP methodology is proposed by decomposing activities, methods, and tasks from conventional ISP process and reorganizing them into DMADOV six-sigma framework. In addition, the usefulness and applicability of the newly proposed methodology are provided using an electronics company example. The methodology enhance the possibility of producing future oriented and beneficial IT projects by associating IT strategy and the projects in the form of quantified causal relationship. Besides, it can also increase the objectivity of IT vision and strategy.

• 대한수학회논문집
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• 제10권2호
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• pp.293-300
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• 1995

Let $R = k[y_1,\cdots,y_n] \otimes E[x_1, \cdots, x_n]$ with characteristic $k = p > 2$ (odd prime), where $$\mid$y_i$\mid$ = 2, $\mid$x_i$\mid$ = 1$ and $y_i = \betax_i, \beta$ is the Bockstein homomorphism. Topologically, $R = H^*(B(Z/p)^n,k)$. For a symmetric group $\sum_n, R^{\sum_n} = k[\sigma_1,\cdots,\sigma_n] \otimes E[d\sigma_1, \cdots, d\sigma_n]$ where d is the derivation satisfying $d(y_i) = x_i$ and $d(x_iy_i) = x_iy_i + x_jy_i, 1 \leq i, j \leq n$. We give a direct proof of this theorem by using induction.