Search results for " Opera"
showing 10 items of 3606 documents
Unit Operations in Approximation Spaces
2010
Unit operations are some special functions on sets. The concept of the unit operation originates from researches of U. Wybraniec-Skardowska. The paper is concerned with the general properties of such functions. The isomorphism between binary relations and unit operations is proved. Algebraic structures of families of unit operations corresponding to certain classes of binary relations are considered. Unit operations are useful in Pawlak's Rough Set Theory. It is shown that unit operations are upper approximations in approximation space. We prove, that in the approximation space (U, R) generated by a reflexive relation R the corresponding unit operation is the least definable approximation i…
Multilinear Fourier multipliers related to time–frequency localization
2013
We consider multilinear multipliers associated in a natural way with localization operators. Boundedness and compactness results are obtained. In particular, we get a geometric condition on a subset A⊂R2d which guarantees that, for a fixed synthesis window ψ∈L2(Rd), the family of localization operators Lφ,ψA obtained when the analysis window φ varies on the unit ball of L2(Rd) is a relatively compact set of compact operators.
An extension of Guo's theorem via k--contractive retractions
2006
Abstract Let X be a infinite-dimensional Banach space. We generalize Guo's Theorem [D.J. Guo, Eigenvalues and eigenvectors of nonlinear operators, Chinese Ann. Math. 2 (1981) 65–80 [English]] to k- ψ -contractions and condensing mappings, under a condition which depends on the infimum k ψ of all k ⩾ 1 for which there exists a k- ψ -contractive retraction of the closed unit ball of the space X onto its boundary.
La investigación en docencia en dirección de operaciones: Tendencias y retos
2011
[EN] Purpose: The objective is to analyse research in Operations Management (OM) teaching published in high impact journals in the area in order to examine trends and set future challenges. Design/methodology/approach: A bibliometric study was carried out of 45 of the main JCR OM and Management journals for the 1995-2010 period. The 129 articles identified on research in OM teaching were analysed. Findings: There is a dearth of articles on teaching in the main OM and Management journals. Sixty-two point two percent of the journals analysed have not published any and the remainder (17) have devoted only 0.4% of all their publications to this subject area. Descriptive and theoretical/conceptu…
A reconsideration of the link between vertical externality and managerial incentives
2018
Previous research revealed that the strategic role of delegation contracts disappears if two quantity†setting firms outsource input production to a monopolistic supplier. I show that this role is restored if the assumption of a downstream duopoly is relaxed. Thus, delegation contracts allow downstream profit†maximizing owners to commit their firms to a behavior that differs from their preferences. This behavior varies nonmonotonically with the number of firms in the downstream market. Corresponding deviations from profit maximization are larger if the upstream monopolist makes a price precommitment. But little to no deviation occurs if the number of firms is large.
Giustizia ambientale e recupero delle aree verdi: il caso di Palermo
2021
L’urban shrinkage è diventata una questione centrale tanto nel dibattito scientifico quanto nell’agenda politica di diverse città europee. Secondo i dati EUROSTAT (2019), circa il 40% delle città europee con più di 200.000 abitanti stanno perdendo popolazione; una contrazione che si esplicita maggiormente, sotto il profilo spaziale, in una progressiva sottoutilizzazione del patrimonio edificato, così come nel contestuale incremento di aree e terreni in stato di abbandono. In questo quadro controverso di mutazione strutturale della città, così come l’abbiamo conosciuta, le politiche urbane alla prova in Europa tentano di declinare la decrescita quale occasione strategica di investimento sull…
Fractional-order theory of thermoelasticicty. I: Generalization of the Fourier equation
2018
The paper deals with the generalization of Fourier-type relations in the context of fractional-order calculus. The instantaneous temperature-flux equation of the Fourier-type diffusion is generalized, introducing a self-similar, fractal-type mass clustering at the micro scale. In this setting, the resulting conduction equation at the macro scale yields a Caputo's fractional derivative with order [0,1] of temperature gradient that generalizes the Fourier conduction equation. The order of the fractional-derivative has been related to the fractal assembly of the microstructure and some preliminary observations about the thermodynamical restrictions of the coefficients and the state functions r…
EFFETTI DELLE CAMPAGNE DI VACCINAZIONE ATTIVA CONTRO L'INFLUENZA TRA IL PERSONALE DELL'AZIENDA OSPEDALIERA UNIVERSITARIA POLICLINICO DI PALERMO (AOUP)
2007
Effetti delle campagne di vaccinazione attiva contro l’influenza tra il personale dell’Azienda Ospedaliera Universitaria Policlinico di Palermo (AOUP…
2007
The role of NFkappaB inducing kinase (NIK) in the pathogenicity of EAE
2014
pathways (PTPN6, SLC3A2, VAV3, DDR1) and modulators of oxidative stress (MT1A, HMOX1, SLC30A1) were also significantly affected by the CBD treatment. The microarray results were confirmed using qPCR on selected gene targets. Immunoblotting demonstrated that CBD reduces IL-17 by decreasing STAT3 phosphorylation and increasing that of STAT5. In conclusion, our observations increase our understanding of the mechanisms of the anti-inflammatory activities of CBD.