Quaderni di Dipartimento
Collezione dei preprint del Dipartimento di Matematica.
La presenza del full-text è lacunosa per i prodotti antecedenti maggio 2006.
Trovati 868 prodotti
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QDD4 - 13/10/2006
Bouchitte, G. ; Fragala, I.
Optimal design of thin plates by a dimension reduction for linear constrained problems | Abstract | | Our main goal is to give a rigorous justification
for the Hessian-constrained problems introduced in [*] and to show how they are linked to the optimal design of thin plates.
To that aim, we study the asymptotic behaviour of a sequence of optimal elastic compliance problems, in the double limit when both the maximal height of the design region and the total volume of the material tend to zero. In the vanishing volume limit, a sequence of linear constrained first order vector problems is obtained, which in turn - in the vanishing thickness limit - produces a new linear constrained problem where both first and
second order gradients appear. When the load is suitably chosen, only the Hessian constraint is active, and we recover exactly the plate optimization problem studied in [*]. Some attention
is also paid to the possible different approaches to the afore mentioned double limit process, in both the cases of real and ficticious materials, which might favour some debate on the modelling of thin plates.
[*] Bouchitte, G. ; Fragala, I.
Optimality conditions for mass design problems and applications to thin plates. Arch. Rat. Mech. Analysis, to appear.
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QDD3 - 02/10/2006
Barchielli, A.
Some stochastic differential equations in quantum optics and measurement theory: the case of counting processes | Abstract | | Stochastic differential equations of jump type are used in the theory of measurements continuous in time in quantum mechanics and have a concrete application in describing direct detection in quantum optics (counting of photons). In the paper the connections are explained among various types of stochastic equations: linear for Hilbert-space unnormalized vectors, non-linear for Hilbert space normalized vectors, linear for trace-class
operators, non-linear for density matrices. These equations allow to construct a posteriori states and probabilities for the counting process describing the direct detection. Relations with master equations and a priori states are also explained. Two concrete applications related to a
two-level atom are presented. |
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QDD2 - 14/06/2006
Klee, V. ; Maluta, E. ; Zanco, C.
Basic properties of evenly convex sets | Abstract | | A subset of a finite-dimensional real vector space is called evenly convex if it is the intersection of a collection of open halfspaces. The study of such sets was initiated in 1952 by Werner Fenchel, who defined a natural polarity operation and mentioned
some of its properties. Over the years since then, evenly convex sets have made occasional appearances in the literature but there has been no systematic study of their basic properties. Such a
study is undertaken in the present paper. |
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QDD1 - 16/05/2006
Salvati, S. ; Fumagalli, E. ; Lo Schiavo, L. ; Secchi, P.
Analysis Of The Methodology Adopted By The Italian Regulatory Authority For Identifying Major Event Days | Abstract | | The Italian regulatory mechanism for quality of service in electricity distribution links the tariff to the SAIDI indicator, net of contributions from exceptional events. In the year 2004 a two-step statistical methodology was introduced to identify major event days (MEDs). This statistical criterion defines a potential MED as a day with a daily CAIDI greater than the mean plus one standard deviation of the annual distribution of daily CAIDI for the relevant spatial unit, the territorial district; within this subset, a MED is a day with a daily SAIDI greater than the mean plus three standard deviations of the daily SAIDI distribution. A one year experience with this approach confirms its validity and suggests an alternative definition of the first step. The suggested definition is still based on a model-free statistical approach, but refers instead to percentiles. This modification would enhance the robustness of the method and enable to drop a currently necessary ex-post adjustment of the regulatory procedure. |
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QDD5 - 01/05/2006
Caliò, F. ; Marchetti, E.; Muresan, V.
On some Volterra-Fredholm integral equations
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650-P - 01/01/2006
Masiero Federica
Regularizing properties for transition semigroups and semilinear parabolic equations in Banach spaces
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648-P - 01/12/2005
Frezzotti, Aldo
A Numerical Investigation of the Steady Evaporation of a Polyatomic Gas
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649-P - 01/12/2005
Gregoratti, Matteo
A Universal Dilation of Discrete Markov Evolutions
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