Search results for " Ordinary"
showing 10 items of 19 documents
Minimally implicit Runge-Kutta methods for Resistive Relativistic MHD
2016
The Relativistic Resistive Magnetohydrodynamic (RRMHD) equations are a hyperbolic system of partial differential equations used to describe the dynamics of relativistic magnetized fluids with a finite conductivity. Close to the ideal magnetohydrodynamic regime, the source term proportional to the conductivity becomes potentially stiff and cannot be handled with standard explicit time integration methods. We propose a new class of methods to deal with the stiffness fo the system, which we name Minimally Implicit Runge-Kutta methods. These methods avoid the development of numerical instabilities without increasing the computational costs in comparison with explicit methods, need no iterative …
A third integrating factor for indefinite integrals of special functions
2020
An integrating factor f ~ x is presented involving the terms in y ′ ′ x and q x y x of the general homogenous second-order linear ordinary differential equation. The new integrating factors obey se...
On critical behaviour in generalized Kadomtsev-Petviashvili equations
2016
International audience; An asymptotic description of the formation of dispersive shock waves in solutions to the generalized Kadomtsev–Petviashvili (KP) equation is conjectured. The asymptotic description based on a multiscales expansion is given in terms of a special solution to an ordinary differential equation of the Painlevé I hierarchy. Several examples are discussed numerically to provide strong evidence for the validity of the conjecture. The numerical study of the long time behaviour of these examples indicates persistence of dispersive shock waves in solutions to the (subcritical) KP equations, while in the supercritical KP equations a blow-up occurs after the formation of the disp…
Responsabilità degli organi di amministrazione e controllo di società a partecipazione pubblica (anche in house) e riparto di giurisdizione
2019
Le disposizioni in tema di responsabilità degli organi di amministrazione e controllo di società a partecipazione pubblica e di giurisdizione applicabile, contenute nell’art. 12, d.lgs. 19 agosto 2016, n. 175, T.U. in materia di società a partecipazione pubblica, e l’espressa previsione all’art. 14 del citato T.U. della fallibilità di tali società hanno dato luogo al moltiplicarsi di azioni civili di responsabilità proposte dalla curatela del fallimento di società a partecipazione pubblica. Nel seno di simili azioni, esperite anche ex art. 2497 c.c. nei confronti dell’ente pubblico socio, la Cassazione si è da ultimo orientata, con le ordinanze a sez. un. del 13 settembre 2018, n. 22406, e …
Determinants of COVID-19 Vaccine Rollouts and Their Effects on Health Outcomes
2022
Background Vaccination against the coronavirus disease (SARS-CoV-2) is understood to be the key way out of the COVID-19 pandemic. Limited evidence exists on the determinants of vaccine rollouts and their health effects at the country level. Objective Examine the determinants of COVID-19 vaccine rollouts and their effects on health outcomes. Methods Ordinary least squares regressions with standard errors clustered at the country level for Cross-section and Panel daily data of vaccinations and various health outcomes (new COVID-19 cases, fatalities, intensive care unit (ICU) admissions) for an unbalanced sample of about 200 countries during the period 16 December 2020 to 20 June 2021. Results…
Floquet theory: exponential perturbative treatment
2001
We develop a Magnus expansion well suited for Floquet theory of linear ordinary differential equations with periodic coefficients. We build up a recursive scheme to obtain the terms in the new expansion and give an explicit sufficient condition for its convergence. The method and formulae are applied to an illustrative example from quantum mechanics.
L'ordinamento giudiziario. Ciclo di seminari (Palermo, marzo-maggio, 2018)
2019
The collected contributions constitute the backbone of a series of seminars on the “Judiciary rules”, which took place in the spring of 2018 in the context of the master's degree course in Law of the University of Palermo. The volume aims to offer the trainee lawyer a closer look at a profile not always investigated of the jurisdictional activity: that of the constitution and functioning of the offices of the ordinary judiciary. Even in their unity, the issues addressed can ideally be divided into two thematic areas: the first aims to provide a general view of the system; the second is dedicated to the analysis of specialized sections and the honorary judiciary. In the appendix, the feature…
DEGENERATE MATRIX METHOD FOR SOLVING NONLINEAR SYSTEMS OF DIFFERENTIAL EQUATIONS
1998
Degenerate matrix method for numerical solving nonlinear systems of ordinary differential equations is considered. The method is based on an application of special degenerate matrix and usual iteration procedure. The method, which is connected with an implicit Runge‐Kutta method, can be simply realized on computers. An estimation for the error of the method is given. First Published Online: 14 Oct 2010
Attendibilità dei modelli per la valutazione dei moduli elastici delle murature suggeriti dalle norme tecniche
2012
In this paper the results of an experimental investigation aimed to the assessment of Young moduli, rigidity moduli and other mechanical properties for different types of masonry are shown. The mechanical characteristics predicted by models proposed by some technical codes were compared against experimental data. This study was motivated by the suggestion of the Masonry Standards Joint Committee's (MSJC) code that, while proposing the use of such models, acknowledges the lack of testing in support of their validation. The experimental investigation has included compressive tests on components (blocks and mortar), diagonal compressive tests and ordinary compressive tests (orthogonally to bed…
An operator-like description of love affairs
2010
We adopt the so--called \emph{occupation number representation}, originally used in quantum mechanics and recently considered in the description of stock markets, in the analysis of the dynamics of love relations. We start with a simple model, involving two actors (Alice and Bob): in the linear case we obtain periodic dynamics, whereas in the nonlinear regime either periodic or quasiperiodic solutions are found. Then we extend the model to a love triangle involving Alice, Bob and a third actress, Carla. Interesting features appear, and in particular we find analytical conditions for the linear model of love triangle to have periodic or quasiperiodic solutions. Numerical solutions are exhibi…