• Bulletin of the Korean Mathematical Society
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• v.36 no.2
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• pp.247-257
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• 1999

In this article, we give an example of local derivation, that is not derivation, on the algebra F(x1,…, xn) of rational functions in x1, …, xn over an infinite field F, and show that if X is a set of symbols and {x1,…, xn} is a finite subset of X, n$\geq$1, then each local derivation of F[x1,…, xn] into F[X] is a F-derivation and each local derivation of F[X] into itself is also a F-derivation.

• Bulletin of the Korean Mathematical Society
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• v.61 no.3
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• pp.813-823
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• 2024

In this paper, we prove that every 2-local derivation on several classes of C^*-algebras, such as unital properly infinite, type I or residually finite-dimensional C^*-algebras, is a derivation. We show that the following statements are equivalent: (1) every 2-local derivation on a C^*-algebra is a derivation, (2) every 2-local derivation on a unital primitive antiliminal and no properly infinite C^*-algebra is a derivation. We also show that every 2-local derivation on a group C^*-algebra C^*(𝔽) or a unital simple infinite-dimensional quasidiagonal C^*-algebra, which is stable finite antiliminal C^*-algebra, is a derivation.

• Journal of the Korean Mathematical Society
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• v.47 no.3
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• pp.523-535
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• 2010

In this paper, we show that Jordan $\tau$-centralizers and local $\tau$-centralizers are $\tau$-centralizers under certain conditions. We also discuss a new type of generalized derivations associated with Hochschild 2-cocycles and introduce a special local generalized derivation associated with Hochschild 2-cocycles. We prove that if $\cal{L}$ is a CDCSL and $\cal{M}$ is a dual normal unital Banach $alg\cal{L}$-bimodule, then every local generalized derivation of above type from $alg\cal{L}$ into $\cal{M}$ is a generalized derivation.

• Communications of the Korean Mathematical Society
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• v.38 no.4
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• pp.1101-1110
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• 2023

At the present paper, we investigate bounded approximately local derivations of ℓ¹-Munn algebra 𝕄_I(𝒜), where I is an arbitrary non-empty set and 𝒜 is an approximately locally unital Banach algebra. Indeed, we show that if _𝒜B(𝒜, 𝒜^*) and B_𝒜(𝒜, 𝒜^*) are reflexive, then every bounded approximately local derivation from 𝕄_I(𝒜) into any Banach 𝕄_I(𝒜)-bimodule X is a derivation. Finally, we apply this result to study bounded approximately local derivations of the semigroup algebra ℓ¹(S), where S is a uniformly locally finite inverse semigroup.

• Bulletin of the Korean Mathematical Society
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• v.58 no.5
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• pp.1193-1208
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• 2021

Let 𝓐 be a von Neumann algebra with no central summands of type I₁. In this article, we study Lie n-derivation on von Neumann algebra and prove that every additive Lie n-derivation on a von Neumann algebra has standard form at zero product as well as at projection product.

• Communications of the Korean Mathematical Society
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• v.38 no.2
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• pp.469-485
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• 2023

Let 𝓐 be a unital Banach *-algebra and 𝓜 be a unital *-𝓐-bimodule. If W is a left separating point of 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 W𝓐 = 𝓐W. Moreover we give a complete description of linear mappings 𝛿 and 𝜏 from 𝓐 into 𝓜 satisfying 𝛿(A)B^* + A𝜏(B)^* = 0 for any A, B ∈ 𝓐 with AB^* = 0 or 𝛿(A)◦B^* + A◦𝜏(B)^* = 0 for any A, B ∈ 𝓐 with A◦B^* = 0, where A◦B = AB + BA is the Jordan product.

• Korean Journal of English Language and Linguistics
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• v.1 no.4
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• pp.629-649
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• 2001

This paper aims to provide an account for the English anaphors under the framework of the recent development of minimalism (Chomsky 1999, 2001). I propose that the anaphor has the uninterpretable [a] feature. The Agree operation erases the [a] feature by feature match. Once the [a] is deleted, the derivation converges, providing a proper interpretation of the anaphor. When there is no matching phi-features, the [a] cannot be eliminated, inducing the derivation to crash. The Agree operation can account for not only the typical local binding cases in English but the apparent long-distance binding cases in the picture-DP and expletive constructions. Consequently, the traditional concept of the binding domain and dichotomy between local and long-distance types are abandoned in favor of the analysis under the framework of minimalism. The minimalist accounts thus maximally simplifies the binding principles, using the general operation Agree only.

• Kyungpook Mathematical Journal
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• v.60 no.4
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• pp.683-710
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• 2020

Let ℕ be the set of nonnegative integers and 𝕬 be a 2-torsion free triangular algebra over a commutative ring ℛ. In the present paper, under some lenient assumptions on 𝕬, it is proved that if Δ = {𝛿_n}_n∈ℕ is a sequence of ℛ-linear mappings 𝛿_n : 𝕬 → 𝕬 satisfying ${\delta}_n([[x,\;y],\;z])\;=\;\displaystyle\sum_{i+j+k=n}\;[[{\delta}_i(x),\;{\delta}_j(y)],\;{\delta}_k(z)]$ for all x, y, z ∈ 𝕬 with xy = 0 (resp. xy = p, where p is a nontrivial idempotent of 𝕬), then for each n ∈ ℕ, 𝛿_n = d_n + 𝜏_n; where d_n : 𝕬 → 𝕬 is ℛ-linear mapping satisfying $d_n(xy)\;=\;\displaystyle\sum_{i+j=n}\;d_i(x)d_j(y)$ for all x, y ∈ 𝕬, i.e. 𝒟 = {d_n}_n∈ℕ is a higher derivation on 𝕬 and 𝜏_n : 𝕬 → Z(𝕬) (where Z(𝕬) is the center of 𝕬) is an ℛ-linear map vanishing at every second commutator [[x, y], z] with xy = 0 (resp. xy = p).

• Journal of Korean Society of Rural Planning
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• v.18 no.3
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• pp.187-200
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• 2012

This article deals with rural village development project of Namsunghyun 'Gamggot(persimmon flower)' area, based on local tourism resources. For more efficient use of local tourism resources, questionnaire surveys for local residents and visitors were conducted. On the base of the results, the vision and objectives were established. And each items of project by division were also considered by the results of such surveys. Finally, priority scores of each items of project, based on importances and weighted value, were derived for more efficient propulsion of project and to construct sustainable rural community.

• Fire Science and Engineering
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• v.17 no.4
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• pp.92-97
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• 2003

It is necessary to build countermeasure for the reduction of flood damage, such as the analysis of shelter activities of local residents and the publishment of flood informations. The control factors for mental refuge activity by the questionnaire survey were classified and estimated into two categories: internal and external ones. Furthermore, the optimal time for refuse activities related to flood risk was derived by hydraulic simulation. The shelter activities considering inundation depth will serve citizen's consensus by exercise, it would aid to support the activities to minimize flood victims.