Search results for " flows"

The Case for Contingent Convertible Debt for Sovereigns

2015

We make the case for sovereigns to issue contingent convertible bonds as a means to forestall debt crises. These instruments contractually stipulate payment standstill, contingent on a sovereign’s credit default swap spread breaching a distress threshold. This is a financial innovation solution to the lack of sovereign debt restructuring mechanisms, limiting ex ante the likelihood of debt crises and imposing ex post risk sharing between creditors and the debtor. The new instruments are contingent contracts addressing neglected risks in sovereign debt. Building on literature for contingent convertible debt for banks we address the design of sovereign contingent debt, including market discipl…

Dehn surgeries and smooth structures on 3-dimensional transitive Anosov flows.

2020

The present thesis is about Dehn surgeries and smooth structures associated with transitive Anosov flows in dimension three. Anosov flows constitute a very important class of dynamical systems, because of its persistent chaotic behaviour, as well as for its rich interaction with the topology of the ambient space. Even if a lot is known about the dynamical and ergodic properties of these systems, there is not a clear understanding about how to classify its different orbital equivalence classes. Until now, the biggest progress has been done in dimension three, where there is a family of techniques intended for the construction of Anosov flows called surgeries.During the realization of this th…

Gradient flows in random walk spaces

2021

El món digital ha comportat l'aparició de molts tipus de dades, de mida i complexitat creixents. De fet, els dispositius moderns ens permeten obtenir fàcilment imatges de major resolució, així com recopilar dades sobre cerques a la xarxa, anàlisis sanitàries, xarxes socials, sistemes d'informació geogràfica, etc. En conseqüència, l'estudi i el tractament d'aquests grans conjunts de dades té un gran interès i valor. En aquest sentit, els grafs ponderats proporcionen un espai de treball natural i flexible on representar les dades. En aquest context, un vèrtex representa una dada concreta i a cada aresta se li assigna un pes segons alguna mesura de semblança adequadament triada entre els vèrte…

Magnetically Driven Swirling Flow Guided by Steady Magnetic Field and Imposed Rotation

1998

MAST-RT0 SOLUTION OF 3D NAVIER STOKES EQUATIONS ON UNSTRUCTURED MESHS. PRELIMINARY RESULTS IN THE LAMINAR CASE

2021

MAST-RT0 solution of 3D Navier Stokes equations in very irregular domains. Preliminary results in the laminar case

2021

A new numerical methodology to solve the 3D Navier-Stokes equations for incompressible fluids within complex boundaries and unstructured body-fitted tetrahedral mesh is presented and validated with three literature and one real-case tests. We apply a fractional time step procedure where a predictor and a corrector problem are sequentially solved. The predictor step is solved applying the MAST (Marching in Space and Time) procedure, which explicitly handles the non-linear terms in the momentum equations, allowing numerical stability for Courant number greater than one. Correction steps are solved by a Mixed Hybrid Finite Elements discretization that assumes positive distances among tetrahedr…

Flots de Smale en dimension 3: présentations finies de voisinages invariants d'ensembles selles

2002

Abstract Given a vector field X on a compact 3-manifold, and a hyperbolic saddle-like set K of that vector field, we consider all the filtering neighbourhood of K: by such, we mean any submanifold which boundary is tranverse to X, the maximal invariant of which is equal to K and which intersection with every orbit of X is connected. Up to topological equivalence, there is only a finite number of such neighbourhoods. We give a finite combinatorial presentation of the global dynamics on any such neighbourhood. A key step is the construction of a unique model of the germ of X along K; this model is, roughly speaking, the simplest three-dimensional manifold and the simplest Smale flow exhibitin…

Parametric measurement of partial damage in building.

2015

The valuation of the property damage is a double appraisal that considers a before situation and an after situation to the damage, reported both to the same moment. An elementary measure of the partial damage is represented, in a first approximation, by the restoration’s cost, when the return of the original situation is possible and economically profitable, this last circumstance imposes that the cost is great or equal to the suffered damage. In the building practice, the restoration of the buildings is often combined with operations of substitution and integration. For the indemnity of the partial damage, the restoration’s cost also includes the lost incomes of the property for the period…

Market Values and Socioeconomic Mixité in Palermo. The Role of Migrants in the Commercial Real Estate Market

2022

Socioeconomic and functional mixité has been an objective placed at the basis of urban development to guide the transformation processes of urban areas, associating it with social inclusion as opposed to the morphological and spatial segregation, often caused by monofunctional zoning. The implementation of social mixité involves all social groups and, particularly, migrant communities that, in turn, are formed by groups with different cultures, nationalities, resources and income levels. The location choices of migrants and native residents produce an ever-changing urban geography of residential, commercial and service activities that directly impact on the real estate market. Migrants’ act…

Free-surface flows solved by means of SPH schemes with numerical diffusive terms

2010

A novel system of equations has been defined which contains diffusive terms in both the continuity and energy equations and, at the leading order, coincides with a standard weakly-compressible SPH scheme with artificial viscosity. A proper state equation is used to associate the internal energy variation to the pressure field and to increase the speed of sound when strong deformations/compressions of the fluid occur. The increase of the sound speed is associated to the shortening of the time integration step and, therefore, allows a larger accuracy during both breaking and impact events. Moreover, the diffusive terms allows reducing the high frequency numerical acoustic noise and smoothing …