• Title/Summary/Keyword: operators on function spaces

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HADAMARD-TYPE FRACTIONAL CALCULUS

  • Anatoly A.Kilbas
    • Journal of the Korean Mathematical Society
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    • v.38 no.6
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    • pp.1191-1204
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    • 2001
  • The paper is devoted to the study of fractional integration and differentiation on a finite interval [a, b] of the real axis in the frame of Hadamard setting. The constructions under consideration generalize the modified integration $\int_{a}^{x}(t/x)^{\mu}f(t)dt/t$ and the modified differentiation ${\delta}+{\mu}({\delta}=xD,D=d/dx)$ with real $\mu$, being taken n times. Conditions are given for such a Hadamard-type fractional integration operator to be bounded in the space $X^{p}_{c}$(a, b) of Lebesgue measurable functions f on $R_{+}=(0,{\infty})$ such that for c${\in}R=(-{\infty}{\infty})$, in particular in the space $L^{p}(0,{\infty})\;(1{\le}{\le}{\infty})$. The existence almost every where is established for the coorresponding Hadamard-type fractional derivative for a function g(x) such that $x^{p}$g(x) have $\delta$ derivatives up to order n-1 on [a, b] and ${\delta}^{n-1}[x^{\mu}$g(x)] is absolutely continuous on [a, b]. Semigroup and reciprocal properties for the above operators are proved.

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[Lp] ESTIMATES FOR A ROUGH MAXIMAL OPERATOR ON PRODUCT SPACES

  • AL-QASSEM HUSSAIN MOHAMMED
    • Journal of the Korean Mathematical Society
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    • v.42 no.3
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    • pp.405-434
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    • 2005
  • We establish appropriate $L^p$ estimates for a class of maximal operators $S_{\Omega}^{(\gamma)}$ on the product space $R^n\;\times\;R^m\;when\;\Omega$ lacks regularity and $1\;\le\;\gamma\;\le\;2.\;Also,\;when\;\gamma\;=\;2$, we prove the $L^p\;(2\;{\le}\;P\;<\;\infty)\;boundedness\;of\;S_{\Omega}^{(\gamma)}\;whenever\;\Omega$ is a function in a certain block space $B_q^{(0,0)}(S^{n-1}\;\times\;S^{m-1})$ (for some q > 1). Moreover, we show that the condition $\Omega\;{\in}\;B_q^{(0,0)}(S^{n-1}\;\times\;S^{m-1})$ is nearly optimal in the sense that the operator $S_{\Omega}^{(2)}$ may fail to be bounded on $L^2$ if the condition $\Omega\;{\in}\;B_q^{(0,0)}(S^{n-1}\;\times\;S^{m-1})$ is replaced by the weaker conditions $\Omega\;{\in}\;B_q^{(0,\varepsilon)}(S^{n-1}\;\times\;S^{m-1})\;for\;any\;-1\;<\;\varepsilon\;<\;0.$

An improved parametric formulation for the variationally correct distortion immune three-noded bar element

  • Mukherjee, Somenath;Manju, S.
    • Structural Engineering and Mechanics
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    • v.38 no.3
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    • pp.261-281
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    • 2011
  • A new method of formulation of a class of elements that are immune to mesh distortion effects is proposed here. The simple three-noded bar element with an offset of the internal node from the element center is employed here to demonstrate the method and the principles on which it is founded upon. Using the function space approach, the modified formulation is shown here to be superior to the conventional isoparametric version of the element since it satisfies the completeness requirement as the metric formulation, and yet it is in agreement with the best-fit paradigm in both the metric and the parametric domains. Furthermore, the element error is limited to only those that are permissible by the classical projection theorem of strains and stresses. Unlike its conventional counterpart, the modified element is thus not prone to any errors from mesh distortion. The element formulation is symmetric and thus satisfies the requirement of the conservative nature of problems associated with all self-adjoint differential operators. The present paper indicates that a proper mapping set for distortion immune elements constitutes geometric and displacement interpolations through parametric and metric shape functions respectively, with the metric components in the displacement/strain replaced by the equivalent geometric interpolation in parametric co-ordinates.

Study on Virtuality and Subjectivity of Augmented Reality in Media Remediation (미디어 재매개적 관점에 의한 증강현실 가상성과 주체성에 대한 연구)

  • Kim, Jin-Kon
    • Journal of Digital Contents Society
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    • v.12 no.4
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    • pp.519-530
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    • 2011
  • This study purposed to interpret subjectivity, which centers on the concept of virtuality embedded in the process of virtualizing contextual awareness and mixing the boundary between realities and virtual realities for renewing the feeling of time and space represented by augmented realities in daily spaces, from the viewpoint of traditional media. By explaining how the reflection of reality is exposed focusing on immediacy and hypermediacy from the viewpoint of media remediation, we found that, different from conventional media, augmented reality enables the screen to function as a part of subject and play a role and, by doing so, converts it to the complete subject of digital media comprehending observers and operators.