1,721,126 research outputs found
A PERTURBATION THEOREM FOR ABSTRACT LINEAR NON-AUTONOMOUS SYSTEMS WITH AN APPLICATION TO A MIXED HYPERBOLIC PROBLEM
No full textWe show a perturbation theorem of Myiadera type for linear abstract non-autonomous Cauchy problems. We exhibit an application to a hyperbolic system with dynamic boundary conditions
On the Cauchy-Dirichlet problem for fully nonlinear equations with fractional time derivative
Full text linkWe consider quite general fully nonlinear mixed Cauchy-Dirichlet problems with a Caputo derivative D-alpha with respect to the time variable and a in (0, 2). Under natural conditions, we show the existence of a local solution u such that D(alpha)u and the second order space derivatives D-xi,D-x j u belong to the class C-alpha theta/2,C-theta ([0, T] x (Omega) over bar), for some T positive, with theta is an element of(0, 1). Moreover, we show the uniqueness of global solutions in the same class of functions
ON HYPERBOLIC MIXED PROBLEMS WITH DYNAMIC AND WENTZELL BOUNDARY CONDITIONS
Full text linkWe study mixed hyperbolic systems with dynamic and Wentzell boundary conditions. The boundary condition contains a tangential operator which is strongly elliptic on the boundary. We prove results of generation of strongly continuous groups and well-posedness
On maximal regularity for abstract parabolic problems with fractional time derivative
No full textWe consider initial value problems for abstract evolution equa- tions with fractional time derivative. Concerning the Caputo derivative Dαu, we show that certain assumptions, which are known to be suf- ficient to get a unique solution with a prescribed regularity, are also necessary. So we establish a maximal regularity result. We consider sim- ilar problems with the Riemann–Liouville derivative ∂αu. Here, we give a complete proof (necessity and sufficiency of the assumptions) of the corresponding maximal regularity results
On maximal regularity for the Cauchy-Dirichlet parabolic problem with fractional time derivative
No full textWe prove two maximal regularity results in spaces of continuous and Hölder continuous functions, for a linear Cauchy-Dirichlet problem with a fractional time derivative Dαt. This derivative is intended in the sense of Caputo and αis taken in (0, 2). In case α =1, we obtain maximal regularity results for parabolic problems already known in mathematical literature
Neurological manifestations of vasculitis
No full textPrimary vasculitis syndromes are diseases characterized by inflammation and necrosis of blood vessel, resulting in vessel occlusion and secondary ischemia of involved tissues. The presentation and clinical manifestations of the vasculitides are extremely variables, and an accurate diagnosis is often difficult. Because neurologic symptoms may be the presenting, the first and in some cases the only manifestations of the underlying disease process, a systematic diagnostic and therapeutic approach to the vasculitic syndromes is essential for the neurologist. Furthemore, a wide variety of clinical manifestations, particularly neurological, of connective tissue disorders may also be related to vasculitis. This review focuses on the neurological manifestations of the late primary vasculitis and of the vasculitis associated with connective tissue disorders. An early diagnosis and the begun of appropiate therapy will prevent the development or progression of central nervous system and peripheral nervous system manifestations
An inverse problem for the beam equation with memory with non homogeneous boundary conditions
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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