Search results for " Opera"
showing 10 items of 3606 documents
The best constant for the Sobolev trace embedding from into
2004
Abstract In this paper we study the best constant, λ 1 ( Ω ) for the trace map from W 1 , 1 ( Ω ) into L 1 ( ∂ Ω ) . We show that this constant is attained in BV ( Ω ) when λ 1 ( Ω ) 1 . Moreover, we prove that this constant can be obtained as limit when p ↘ 1 of the best constant of W 1 , p ( Ω ) ↪ L p ( ∂ Ω ) . To perform the proofs we will look at Neumann problems involving the 1-Laplacian, Δ 1 ( u ) = div ( Du / | Du | ) .
The best choice problem with an unknown number of objects
1993
The secretary problem with a known prior distribution of the number of candidates is considered. Ifp(i)=p(N=i),i ∈ [α, β] ∩ ℕ, whereα=inf{i ∈ℕ:p(i) > 0} andβ=sup{i ∈ℕ:p(i)≳0}, is the prior distribution of the numberN of candidates it will be shown that, if the optimal stopping rule is of the simple form, then the optimal stopping indexj=minΓ satisfies asymptotically (asβ → ∞) the equationj=exp $${{\left[ {\left( {\sum\limits_{i = max(\alpha ,j)}^\beta {p(i) \log (i)/i} } \right)} \right]} \mathord{\left/ {\vphantom {{\left[ {\left( {\sum\limits_{i = max(\alpha ,j)}^\beta {p(i) \log (i)/i} } \right)} \right]} {\left. {\left( {\sum\limits_{i = max(\alpha ,j)}^\beta {p(i)/i} } \right) - 1} \ri…
Some Quantitative Aspects of Stability Management Strategy in a Bank
2012
Abstract The stability of commercial bank system is the result of balanced development, which can be characterised by equilibrium and security over a longer period of time. The history of commercial bank system development indicates that reaching and sustaining this qualitative and quantitative state requires regulations and management. One of the most important parts of commercial bank management system is correctly chosen strategy in the circumstances of a changing environment. Strategy gives a possibility to look into the future of the commercial bank, forecast its goals, areas, scale and potential operational results in relation to resource sources and expenses. Nowadays a commercial ba…
Regulation and efficiency: the case of European railways
2001
Abstract During the long period of regulation of the railway system in Europe (1950s–1990s) the companies notably improved their levels of productivity. However, parallel to this, the state of their financial accounts also significantly worsened. In order to explain this fact we have estimated both cost and revenue frontier functions, calculating the losses associated with both cost and revenue inefficiencies as well as inefficiencies on the cost side. The results obtained show the existence of significant potential losses of revenue, which can be explained above all by the strong policy of regulation and intervention reigning in this period. A better commercial policy and a supply adapted …
La committenza gesuitica e la pittura a Palermo tra XVI e XVIII secolo
Il presente lavoro di ricerca mira ad approfondire e arricchire, mediante nuove acquisizioni, lo studio in merito alle opere pittoriche di committenza gesuitica custodite presso le fondazioni palermitane dell’Ordine: chiesa del Gesù a Casa Professa, Collegio Massimo dei Gesuiti, chiesa di San Stanislao Kostka e chiesa di San Francesco Saverio. A queste si aggiungono i dipinti di committenza della Compagnia trasferiti presso altre sedi. Ulteriore intento è quello di organizzare in maniera più organica la trattazione delle commissioni artistiche dell’Ordine a Palermo, che si presentava dispersiva e frammentaria. Tra i risultati più significativi si annovera il ritrovamento di un ciclo di affr…
Assessing interactional skills in a paired speaking test : raters’ interpretation of the construct
2019
The operationalization of interactional competence (IC) within the paired speaking test format allows for a range of interactional skills to be tested. However, in terms of assessment, challenges are posed with regard to the co-constructed nature of IC, making investigations into raters’ perceptions of the construct essential to inform test score interpretation. This qualitative study explores features of IC that raters attended to as they evaluated performances in a paired speaking test, part of a Swedish national test of English as a Foreign Language (EFL). Two groups of raters, 17 EFL teachers from Sweden, using national standards based on the Common European Framework of Reference for L…
Fixed points in weak non-Archimedean fuzzy metric spaces
2011
Mihet [Fuzzy $\psi$-contractive mappings in non-Archimedean fuzzy metric spaces, Fuzzy Sets and Systems, 159 (2008) 739-744] proved a theorem which assures the existence of a fixed point for fuzzy $\psi$-contractive mappings in the framework of complete non-Archimedean fuzzy metric spaces. Motivated by this, we introduce a notion of weak non-Archimedean fuzzy metric space and prove that the weak non-Archimedean fuzzy metric induces a Hausdorff topology. We utilize this new notion to obtain some common fixed point results for a pair of generalized contractive type mappings.
Weak commutation relations of unbounded operators and applications
2011
Four possible definitions of the commutation relation $[S,T]=\Id$ of two closable unbounded operators $S,T$ are compared. The {\em weak} sense of this commutator is given in terms of the inner product of the Hilbert space $\H$ where the operators act. Some consequences on the existence of eigenvectors of two number-like operators are derived and the partial O*-algebra generated by $S,T$ is studied. Some applications are also considered.
Monitoring multidimensional phenomena with a multicriteria composite performance interval approach
2021
[EN] In the last two decades, the construction of composite indicators to measure and compare multidimensional phenomena in a broad spectrum of domains has increased considerably. Different methodological approaches are used to summarise huge datasets of information in a single figure. This paper proposes a new approach that consists in computing a multicriteria composite performance interval based on different aggregation rules. The suggested approach provides an additional layer of information as the performance interval displays a lower bound from a non-compensability perspective, and an upper bound allowing for full-compensability. The outstanding features of this proposal are: 1) a dis…
Variational differential inclusions without ellipticity condition
2020
The paper sets forth a new type of variational problem without any ellipticity or monotonicity condition. A prototype is a differential inclusion whose driving operator is the competing weighted $(p,q)$-Laplacian $-\Delta_p u+\mu\Delta_q u$ with $\mu\in \mathbb{R}$. Local and nonlocal boundary value problems fitting into this nonstandard setting are examined.