Results 71 to 80 of about 714 (196)
ON COMPLETE RIESZ–FISCHER SEQUENCES IN A HILBERT SPACE
Проблемы анализаWe prove that if {𝑓_𝑛}^\infty_{n=1} is a complete Riesz–Fischer sequence in a separable Hilbert space 𝐻, then 𝑇 :={𝑓 \in 𝐻 : \Sum ...
Elias Zikkos
doaj +1 more source
Abstract and Applied Analysis, 2011 This paper is concerned with analyzing the mathematical properties, such as the regularity and stability of nonstationary biorthogonal wavelet systems based on exponential B-splines.
Yeon Ju Lee, Jungho Yoon
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Ecology and Evolution, Volume 16, Issue 6, June 2026.Plumage coloration is widely recognized as an important component in intraspecific communication. Our aim was to examine the variation of oxidative parameters and their associations with the coloration of two different nestling plumage traits in collared flycatchers (Ficedula albicollis).
Gabriella Kőmüves +5 more
wiley +1 more source
Characterizing Riesz Bases via Biorthogonal Riesz-Fischer sequences
, 2022 In this note we prove that if two Riesz-Fischer sequences in a separable Hilbert space $H$ are biorthogonal and one of them is complete in $H$, then both sequences are Riesz bases for $H$. This complements a recent result by D. T. Stoeva where the same conclusion holds if one replaces the phrase ``Riesz-Fischer sequences'' by ``Bessel sequences''.
openaire +2 more sources
Ibn Al-Haitham Journal for Pure and Applied Sciences, 2017 The aim of this paper is prove a theorem on the Riesz mean of expansions with respect to Riesz bases, which extends the previous results of Loi and Tahir on the Schrodinger operator to the operator of 4-th order.
M. B. Tahir, A. A. Aswhad
doaj
Building a Digital Twin for Material Testing: Model Reduction and Data Assimilation
Proceedings in Applied Mathematics and Mechanics, Volume 26, Issue 2, June 2026.ABSTRACT The rapid advancement of industrial technologies, data collection, and handling methods has paved the way for the widespread adoption of digital twins (DTs) in engineering, enabling seamless integration between physical systems and their virtual counterparts.
Rubén Aylwin +5 more
wiley +1 more source
Financial Statement Information and Equity Value: The Role of Real Options Characteristics
Financial Management, Volume 55, Issue 2, Page 301-328, Summer 2026.ABSTRACT This paper examines whether firm‐specific real options characteristics are equity value‐relevant beyond valuation estimates anchored in financial statements. Using extensive historical data for the United Kingdom, we assess and compare the forecast accuracy and explanatory power for stock prices of equity valuation models based on residual ...
Mingyu (Chandler) Chen +2 more
wiley +1 more source
Discrete Subspace Multiwindow Gabor Frames and Their Duals
Abstract and Applied Analysis, 2013 This paper addresses discrete subspace multiwindow Gabor analysis. Such a scenario can model many practical signals and has potential applications in signal processing.
Yun-Zhang Li, Yan Zhang
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Hub‐and‐Spoke Collusion With a Third‐Party Pricing Algorithm
The Journal of Industrial Economics, Volume 74, Issue 2, Page 181-196, June 2026.ABSTRACT A data analytics company delivers an efficiency by supplying a pricing algorithm that allows prices to more effectively respond to demand variation. In this setting, I consider a new form of hub‐and‐spoke collusion: A data analytics company (hub) coordinates the prices of competitors (spokes) through its pricing algorithm.
Joseph E. Harrington Jr.
wiley +1 more source
An Angle Criterion for Riesz Bases [PDF]
, 1999 We present a characterization of Riesz bases in terms ofthe angles between certain finite dimensional subspaces.
Bittner, B., Lindner, Alexander M
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