1,721,221 research outputs found
Introduction: Reshaping International Norms and State Models? China and Russia's New Role in the World Arena
No full textThe introduction to the volume presents a discussion on the resurgence of the Strong State in both China and Russia
BV solutions of the semidiscrete upwind scheme
No full textWe consider the semidiscrete upwind scheme u(t, x), + 1/ε (f(u(t, x)) - f(u(t, x - ε))) = 0. (1) We prove that if the initial data ū of (1) has small total variation, then the solution uε(t) has uniformly bounded BV norm, independent of t, ε. Moreover by studying the equation for a perturbation of (1) we prove the Lipschitz-continuous dependence of uε(t) on the initial data. Using a technique similar to the vanishing-viscosity case, we show that as ε → 0 the solution uε(t) converges to a weak solution of the corresponding hyperbolic system, ut + f(u)x, = 0. (2) Moreover this weak solution coincides with the trajectory of a Riemann semigroup, which is uniquely determined by the extension of Liu's Riemann solver to general hyperbolic systems
On the Shift Differentiability of the Flow generated by a Hyperbolic System of Conservation Laws
No full textWe consider the notion of shift tangent vector introduced in [7] for real valued BV functions and introduced in [9] for vector valued BV functions. These tangent vectors act on a function u ∈ L1 shifting horizontally the points of its graph at different rates, generating in such a way a continuous path in L1. The main result of [7] is that if the semigroup S generated by a scalar strictly convex conservation law is shift differentiable, i.e. paths generated by shift tangent vectors at u0 are mapped in paths generated by shift tangent vectors at Stu0 for almost every t ≥ 0. This leads to the introduction of a sort of differential, the "shift differential", of the map u0 → Stu0. In this paper, using a simple decomposition of u ∈ BV in terms of its derivative, we extend the results of [9] and we give a unified definition of shift tangent vector, valid both in the scalar and vector case. This extension allows us to study the shift differentiability of the flow generated by a hyperbolic system of conservation laws
Southeastern Europe
No full textIl sito della rivista è: http://www.brill.nl/seeu. Southeastern Europe è inserita fra le riviste di fascia A dell'area 14. Southeastern Europe è una rivista specialistica il cui obiettivo è fornire analisi degli sviluppi sociali, politici ed economici nell’area del Sud-Est Europeo tramite un approccio fortemente multidisciplinare. Southeastern Europe applica un rigido sistema di peer-reviews. Southeastern Europe è una rivista specialistica che opera con l’obiettivo di pubblicare ricerche innovative sugli sviluppi contemporanei nell’area del Sud-Est Europa. Southeastern Europe utilizza un approccio fortemente multidisciplinare e comparativo. La rivista pubblica numeri tematici composti da essays, articoli, interviste, dibattiti e recensioni. Southeastern Europe è promossa dall’ Università di Bologna e prodotta in collaborazione con il Europe and the Balkans International Network . La sede della redazione è presso il Dipartimento di Scienze Politiche e Sociali dell’Università di Bologna – sede di Forlì. La rivista è uscita fra il 2009 e il 2011 semestralmente (nel 2008, al momento del nostro rilevamento della rivista come responsabilità scientifica, il vol. XXXI-XXXII è stato pubblicato come numero doppio) e dal 2012 esce regolarmente come quadrimestrale. La rivista ha come co-editor in chief: Anna Krasteva (New Bulgarian University, Sofia). Inoltre, la sua struttura è così articolata: Associate Editors: Florian Bieber (University of Kent, UK) Gvozdan Flego (Univerity of Zagreb, Croatia) Henry Huttenbach (the City College of New York, USA) Book Review Editor : Vjeran Pavlakovic, (University of Rijeka, Croatia) Editorial Managers: Editorial assistant Sara Barbieri (Istituto per l'Europa Centro-Orientale e Balcanica, Italy) e Book Review assistant: Leonas Tolvaisis (Istituto per l'Europa Centro-Orientale e Balcanica, Italy). La rivista ha un comitato scientifico internazionale composto da: Vesna Bojcic (London School of Economics and Political Science, UK), George Contogeorgis, (Pantheion University, Greece), Zdravko Grebo, (University of Sarajevo, BiH), Damir Grubiša, (University of Zagreb, Croatia), Dušan Janjic (Forum for Ethnic Relations, Belgrade, Serbia), Julie Mostov, (Drexel University, USA) Günay Göksu Ozdogan (Marmara University, Turkey), Francesco Privitera, (University of Bologna, Italy), Sabrina P. Ramet (The Norwegian University of Science and Technology, Trondheim), Violette Rey, (Ecole Normale Superieure, Lyon, France), Mikola Riabchuk, (University of Kiev, Ukraine), Rudolf Rizman, (University of Ljubljana, Slovenia), Mitja Žagar, (Institute for Ethnic Studies, Slovenia)
Extremal Faces of the Range of a Vector Measure and a Theorem of Lyapunov
No full textAbstractA theorem of Lyapunov states that the range R(μ) of a nonatomic vector measure μ is compact and convex. In this paper we give a condition to detect the dimension of the extremal faces of R(μ) in terms of the Radon–Nikodym derivative of μ with respect to its total variation |μ|: namely, R(μ) has an extremal face of dimension less than or equal tokif and only if the set (x1,…,xk+1) such thatf(x1),…,f(xk+1) are linear dependent has positive |μ|⊗(k+1)-measure. Decomposing the setXin a suitable way, we obtain R(μ) as a vector sum of sets which are strictly convex. This result allows us to study the problem of the description of the range of μ if μ has atoms, achieving an extension of Lyapunov's theorem
SBV regularity of Systems of Conservation Laws and Hamilton-Jacobi Equation
Full text linkWe review the SBV regularity for solutions to hyperbolic systems of conservation laws and Hamilton-Jacobi equations. We give an overview of the techniques involved in the proof, and a collection of related problems concludes the paper
A Glimm type functional for a special Jin-Xin relaxation model
No full textWe consider a special case of the Jin-Xin relaxation systems
u(t) + v(x) = 0, v(t) + lambda (2)u(x) = (F(u) - v)/epsilon. (*)
We assume that the integral curves of the eigenvectors r(i) of DF(u) are straight lines. In this setting we prove that fur every initial data ii, v with sufficiently small total variation the solution (u(epsilon), v(epsilon)) of (*) is well defined for all t > 0, and its total variation satisfies a uniform bound, independent of t, epsilon. Moreover, as epsilon tends to 0(+), the solutions (u(epsilon), v(epsilon)) converge to a unique limit (u(t), v(t)): u(t) is thr: unique entropic solution of the corresponding hyperbolic system u(t) + F(u)(x) = 0 and v(t, x) = F (u(t, x)) for all t > 0, a.e. x is an element of R. The proofs rely on the introduction of a new functional for the solutions of (*), corresponding to the Glimm interaction potential for the approaching waves of different families. (C) 2001 Editions scientifiques et medicales Elsevier SAS. AMS classification: 35
Interaction estimates and Glimm functional for general hyperbolic systems
No full textWe consider the problem of writing Glimm type interaction estimates for the hyperbolic system ut + A(u)ux = 0. (0.1) The aim of these estimates is to prove that there is Glimm-type functional Q(u) such that Tot.Var.(u) + C1Q(u) is lower semicontinuous w.r.t. L1 - norm, (0.2) with C1 sufficiently large, and u with small BV norm. In the first part we analyze the more general case of quasilinear hyperbolic systems. We show that in general this result is not true if the system is not in conservation form: there are Riemann solvers, identified by selecting an entropic conditions on the jumps, which do not satisfy the Glimm interaction estimate (0.2). Next we consider hyperbolic systems in conservation form, i.e. A(u) = D f(u). In this case, there is only one entropic Riemann solver, and we prove that this particular Riemann solver satisfies (0.2) for a particular functional Q, which we construct explicitly. The main novelty here is that we suppose only the Jacobian matrix Df(u) strictly hyperbolic, without any assumption on the number of inflection points of f. These results are achieved by an analysis of the growth of Tot.Var.(u) when nonlinear waves of (0.1) interact, and the introduction of a Glimm type functional Q, similar but not equivalent to Liu's interaction functional [11]
2015. Nationalities Papers
No full textNationalities Papers is the journal of the Association for the Study of Nationalities, bringing together scholars worldwide working on nationalism, ethnicity, ethnic conflict and national identity in Central Europe, the Balkans, the former Soviet Union, the Caucasus, the Turkic world and Central Eurasia. The journal also publishes contributions on theories of nationalism, comparative studies of nationalism, and trans- and supranational aspects of interethnic relations and national identity. Nationalities Papers publishes timely, high quality articles from a variety of disciplines, including history, political science, sociology, anthropology, and literature.
All articles published in Nationalities Papers have undergone rigorous peer review, based on initial editor screening and double-blind refereeing by a minimum of two anonymous referees.
Find out how you can access this journal at Taylor & Francis Online - Nationalities Papers
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