共查询到20条相似文献,搜索用时 15 毫秒
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Aequationes mathematicae - We prove that every K–subadditive set–valued map weakly K–upper bounded on a “large” set (e.g. not null–finite, not... 相似文献
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Merrilyn Goos John ODonoghue Mire N Rordin Fiona Faulkner Tony Hall Niamh OMeara 《ZDM》2020,52(5):893-905
“Out-of-field” teaching refers to the practice of assigning secondary school teachers to teach subjects that do not match their training or edu 相似文献
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Journal of Heuristics - 相似文献
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Designs, Codes and Cryptography - In this work, we study functions that can be obtained by restricting a vectorial Boolean function $$F :\mathbb {F}_{2}^n \rightarrow \mathbb {F}_{2}^n$$ to an... 相似文献
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Attila Nagy 《Semigroup Forum》2011,83(2):289-303
By the separator
\operatornameSepA\operatorname{\mathit{Sep}}A of a subset A of a semigroup S we mean the set of all elements x of S which satisfy conditions xA⊆A, Ax⊆A, x(S−A)⊆(S−A), (S−A)x⊆(S−A). In this paper we deal with the separator of subsets of semigroups. 相似文献
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The quaternion algebraB[j] over a commutative ringB with 1 defined byS. Parimala andR. Sridharan is generalized in two directions: (1) the ringB may be non-commutative with 1, and (2)j
2 may be any invertible element (not necessarily –1). LetG={} be an automorphism group ofB of order 2, andA={b inB| (b)=b}. LetB[j] be a generalized quaternion algebra such thataj (a) for eacha inB. It will be shown thatB is Galois (for non-commutative ring extensions) overA which is contained in the center ofB if and only ifB[j] is Azumaya overA. Also,A[j] is a splitting ring forB[j] such thatA[j] is Galois overA. Moreover, we shall determine which automorphism group ofA[j] is a Galois group. 相似文献
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Let $X$ and $ Z$ be Banach spaces, $A$ a closed subset of $X$ and a mapping $f:A\rightarrow Z$ . We give necessary and sufficient conditions to obtain a $C^1$ smooth mapping $F:X \rightarrow Z$ such that $F_{\mid _A}=f$ , when either (i) $X$ and $Z$ are Hilbert spaces and $X$ is separable, or (ii) $X^*$ is separable and $Z$ is an absolute Lipschitz retract, or (iii) $X=L_2$ and $Z=L_p$ with $1<p<2$ , or (iv) $X=L_p$ and $Z=L_2$ with $2<p<\infty $ , where $L_p$ is any separable Banach space $L_p(S,\Sigma ,\mu )$ with $(S,\Sigma ,\mu )$ a $\sigma $ -finite measure space. 相似文献
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We characterize the restrictions of first-order Sobolev functions to regular subsets of a homogeneous metric space and prove the existence of the corresponding linear extension operator. 相似文献
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Tamás Dékány 《Semigroup Forum》2014,89(3):600-608
An example of an extension of a completely simple semigroup \(U\) by a group \(H\) is given which cannot be embedded into the wreath product of \(U\) by \(H\) . On the other hand, every central extension of \(U\) by \(H\) is shown to be embeddable in the wreath product of \(U\) by \(H\) , and any extension of \(U\) by \(H\) is proved to be embeddable in a semidirect product of a completely simple semigroup \(V\) by \(H\) where the maximal subgroups of \(V\) are direct powers of those of \(U\) . 相似文献
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Sheng Wang Wang Ming Chu Gao 《Proceedings of the American Mathematical Society》1999,127(6):1651-1663
This paper establishes automatic extensions for local regularized semigroups and local regularized cosine functions in a certain sense and applies the results to abstract Cauchy problems.
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Roman Ger 《Results in Mathematics》1994,26(3-4):281-289
Let X, Y be two linear spaces over the field ? of rationals and let D ≠ ? be a (?—convex subset of X. We show that every function ?: D → Y satisfying the functional equation $${\mathop\sum^{n+1}\limits_{j=0}}(-1)^{n+1-j}\Bigg(^{n+1}_{j}\Bigg)f\Bigg((1-{j\over {n+1}})x+{j\over{n+1}}y\Bigg)=0,\ \ \ x,y\in\ D,$$ admits an extension to a function F: X → Y of the form $$F(x)=A^o+A^1(x)+\cdot\cdot\cdot+A^n(x),\ \ \ x\in\ X,$$ where A o ∈ Y, Ak(x) ? Ak(x,…,x), x ∈ X, and the maps A k: X k → Y are k—additive and symmetric, k ∈ {1,…, n}. Uniqueness of the extension is also discussed. 相似文献
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For any numerical function we give sufficient conditions for resolving the controlled extension problem for a closed subset A of a normal space X. Namely, if the functions , and satisfy the equality E(f(a),g(a))=h(a), for every a∈A, then we are interested to find the extensions f? and ? of f and g, respectively, such that , for every x∈X. We generalize earlier results concerning E(u,v)=u·v by using the techniques of selections of paraconvex-valued LSC mappings and soft single-valued mappings. 相似文献
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The problem of extending partial functions is considered from the general viewpoint. Some aspects of this problem are illustrated by examples, which are concerned with typical real-valued partial functions (e.g. semicontinuous, monotone, additive, measurable, possessing the Baire property). 相似文献
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Saulius Norvidas 《Lithuanian Mathematical Journal》2017,57(2):236-243
Here we deal with the following question: Is it true that, for any closed interval on the real line ? that does not contain the origin, there exists a characteristic function f such that f(x) coincides with the normal characteristic function \( {\mathrm{e}}^{-{x}^2/2} \) on this interval but f(x) ? \( {\mathrm{e}}^{-{x}^2/2} \) on ?? The answer to this question is positive. We study a more general case of an arbitrary characteristic function g of a continuous probability density, instead of \( {\mathrm{e}}^{-{x}^2/2} \). 相似文献