Results 61 to 70 of about 34,900 (279)
Hyperbolic-parabolic singular perturbation for Kirchhoff equations with weak dissipation [PDF]
, 2009 We consider Kirchhoff equations with a small parameter epsilon in front of the second-order time-derivative, and a dissipative term whose coefficient may tend to 0 as t -> + infinity (weak dissipation).
Ghisi, Marina, Gobbino, Massimo
core +2 more sources
Hidden symmetries of two-field cosmological models
, 2019 We determine the most general time-independent Noether symmetries of two-field cosmological models with rotationally-invariant scalar manifold metrics.
Anguelova, Lilia +2 more
core +1 more source
Mixed Problems for Singular and Degenerate Hyperbolic Equations
Publications of the Research Institute for Mathematical Sciences, 1987 The author considers a mixed problem for a degenerate hyperbolic equation with principal symbol \(\prod^ m_{j=1}(\tau-t^ k\Lambda_ j(t,x,y;\xi,\eta))\), where \(k\) is a real number, \(k>0\), the variables \((\xi,\eta)\) are dual to \((x,y)\), and the \(\Lambda^ j(t,x,y;\xi,\eta)\) are real and distinct. For this problem the author proves existence and
openaire +3 more sources
A Systematic Comparison of Alpha‐Synuclein Seed Amplification Assays for Increasing Reproducibility
Annals of Clinical and Translational Neurology, EarlyView.ABSTRACT Seed amplification assays (SAAs) enable ultrasensitive detection of misfolded α‐synuclein across biofluids and tissues. Yet, heterogeneity in protocols limits cross‐study comparability and clinical translation. Here, we review α‐synuclein SAA methods and their performance across various biological matrices.
Manuela Amaral‐do‐Nascimento +3 more
wiley +1 more source
Annals of Clinical and Translational Neurology, EarlyView.ABSTRACT Background Collaterals are crucial factors that influence the infarct growth rate (IGR). We aimed to determine whether a comprehensive multimodal collateral score (MCS), incorporating collateral assessment at the arterial, tissue, and venous levels, is associated with functional independence and provides incremental prognostic value over ...
Giorgio Busto +12 more
wiley +1 more source
Oblique derivative problems for second-order hyperbolic equations with degenerate curve
Electronic Journal of Differential Equations, 2011 The present article concerns the oblique derivative problem for second order hyperbolic equations with degenerate circle arc. Firstly the formulation of the oblique derivative problem for the equations is given, next the representation and estimates ...
Guo-Chun Wen
doaj
On a Class of Degenerate Abstract Parabolic Problems and Applications to Some Eddy Current Models
, 2020 We present an abstract framework for parabolic type equations which possibly degenerate on certain spatial regions. The degeneracies are such that the equations under investigation may admit a type change ranging from parabolic to elliptic type problems.
Pauly, Dirk +3 more
core
On Local Solutions of a Mildly Degenerate Hyperbolic Equation
Journal of Mathematical Analysis and Applications, 1999 In this paper existence and uniqueness of local solutions for the initial boundary problem associated to a second order hyperbolic equation are established. More precisely, the following problem is considered: \[ \begin{gathered} u_{tt}-M\left(\int_\Omega|Du|^2dx\right)a(x)\Delta u=0\qquad \text{in }\Omega\times\mathbb R_+,\\ u(x,t)\bigl|_{\partial ...
Aassila, Mohammed, Kaya, Dogan
openaire +1 more source
A Robust Adaptive One‐Sample‐Ahead Preview Super‐Twisting Sliding Mode Controller
International Journal of Adaptive Control and Signal Processing, EarlyView.Block Diagram of the Robust Adaptive One‐Sample‐Ahead Preview Super‐Twisting Sliding Mode Controller. ABSTRACT This article introduces a discrete‐time robust adaptive one‐sample‐ahead preview super‐twisting sliding mode controller. A stability analysis of the controller by Lyapunov criteria is developed to demonstrate its robustness in handling both ...
Guilherme Vieira Hollweg +5 more
wiley +1 more source
Electronic Journal of Differential Equations, 2009 This article concerns the oblique derivative problems for second-order quasilinear degenerate equations of mixed type with several characteristic boundaries, which include the Tricomi problem as a special case.
Guo Chun Wen
doaj