56 research outputs found
Influence of floral structure and flower bud quality on productivity and fruit shape in different apple cultivars
Global and exponential attractors for a Ginzburg-Landau model of superfluidity
The long-time behavior of the solutions for a non-isothermal model in
superfluidity is investigated. The model describes the transition between the
normal and the superfluid phase in liquid 4He by means of a non-linear
differential system, where the concentration of the superfluid phase satisfies
a non-isothermal Ginzburg-Landau equation. This system, which turns out to be
consistent with thermodynamical principles and whose well-posedness has been
recently proved, has been shown to admit a Lyapunov functional. This allows to
prove existence of the global attractor which consists of the unstable manifold
of the stationary solutions. Finally, by exploiting recent techniques of
semigroups theory, we prove the existence of an exponential attractor of finite
fractal dimension which contains the global attractor.Comment: 39 page
Non-existence and uniqueness results for supercritical semilinear elliptic equations
Non-existence and uniqueness results are proved for several local and
non-local supercritical bifurcation problems involving a semilinear elliptic
equation depending on a parameter. The domain is star-shaped but no other
symmetry assumption is required. Uniqueness holds when the bifurcation
parameter is in a certain range. Our approach can be seen, in some cases, as an
extension of non-existence results for non-trivial solutions. It is based on
Rellich-Pohozaev type estimates. Semilinear elliptic equations naturally arise
in many applications, for instance in astrophysics, hydrodynamics or
thermodynamics. We simplify the proof of earlier results by K. Schmitt and R.
Schaaf in the so-called local multiplicative case, extend them to the case of a
non-local dependence on the bifurcation parameter and to the additive case,
both in local and non-local settings.Comment: Annales Henri Poincar\'e (2009) to appea
Marking their own homework: The pragmatic and moral legitimacy of industry self-regulation
When is industry self-regulation (ISR) a legitimate form of governance? In principle, ISR can serve the interests of participating companies, regulators and other stakeholders. However, in practice, empirical evidence shows that ISR schemes often under-perform, leading to criticism that such schemes are tantamount to firms marking their own homework. In response, this paper explains how current management theory on ISR has failed to separate the pragmatic legitimacy of ISR based on self-interested calculations, from moral legitimacy based on normative approval. The paper traces three families of management theory on ISR and uses these to map the pragmatic and moral legitimacy of ISR schemes. It identifies tensions between the pragmatic and moral legitimacy of ISR schemes, which the current ISR literature does not address, and draws implications for the future theory and practice of ISR
Contrôle des externalités avec asymétrie d'information : recyclage des métaux ferreux et effet de "ruée vers l'or"
Cahier du Laboratoire d'Econométrie ; 2005-030 ; Diffusion du document : INRA Etablissement d'Economie et Sociologie rurales 65 boulevard de Brandebourg 94205 Ivry Cedex (FRA) ; Cote de localisation : PAR. FLE. 2005/P1915 2005-030Les auteurs proposent un modèle de l'organisation monopsonistique d'une filière de recyclage des métaux ferreux. Ce type d'activité se distingue par des externalités négatives propres à la collecte et de fortes asymétries d'information sur la qualité des matières collectées. Après avoir mis en lumière un effet de "ruée vers l'or" (la relation entre le niveau de prix et les externalités négatives de collecte), ils expliquent comment un recycleur monopsoneur régule l'activité de collecte en contrôlant le degré d'asymétrie d'information. En particulier, plus la valeur d'une ferraille est élevée, plus les asymétries d'information doivent être importantes. En terme de bien-être ceci peut être efficace mais induit un dilemme équité-efficacité, lequel est d'autant plus marqué que l'on intègre la dimension environnementale du problème
Contrôle des externalités avec asymétrie d'information : recyclage des métaux ferreux et effet de "ruée vers l'or"
Cahier du Laboratoire d'Econométrie ; 2005-030 ; Diffusion du document : INRA Etablissement d'Economie et Sociologie rurales 65 boulevard de Brandebourg 94205 Ivry Cedex (FRA) ; Cote de localisation : PAR. FLE. 2005/P1915 2005-030Les auteurs proposent un modèle de l'organisation monopsonistique d'une filière de recyclage des métaux ferreux. Ce type d'activité se distingue par des externalités négatives propres à la collecte et de fortes asymétries d'information sur la qualité des matières collectées. Après avoir mis en lumière un effet de "ruée vers l'or" (la relation entre le niveau de prix et les externalités négatives de collecte), ils expliquent comment un recycleur monopsoneur régule l'activité de collecte en contrôlant le degré d'asymétrie d'information. En particulier, plus la valeur d'une ferraille est élevée, plus les asymétries d'information doivent être importantes. En terme de bien-être ceci peut être efficace mais induit un dilemme équité-efficacité, lequel est d'autant plus marqué que l'on intègre la dimension environnementale du problème
Recommended from our members
Dynamics of the Ginzburg-Landau equations of superconductivity
This article is concerned with the dynamical properties of solutions of the time-dependent Ginzburg-Landau (TDGL) equations of superconductivity. It is shown that the TDGL equations define a dynamical process when the applied magnetic field varies with time, and a dynamical system when the applied magnetic field is stationary. The dynamical system describes the large-time asymptotic behavior: Every solution of the TDGL equations is attracted to a set of stationary solutions, which are divergence free. These results are obtained in the {open_quotes}{phi} = -{omega}({gradient}{center_dot}A){close_quotes} gauge, which reduces to the standard {close_quotes}{phi} = -{gradient}{center_dot}A{close_quotes} gauge if {omega} = 1 and to the zero-electric potential gauge if {omega} = 0; the treatment captures both in a unified framework. This gauge forces the London gauge, {gradient}{center_dot}A = 0, for any stationary solution of the TDGL equations
Nodal structure of the solution of a cooperative elliptic system near an eigenvalue.
International audienc
- …