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971.
Heinz Langer Alexander Markus Vladimir Matsaev 《Integral Equations and Operator Theory》2009,63(4):533-545
In this note we continue the study of spectral properties of a self-adjoint analytic operator function A(z) that was started in [5]. It is shown that if A(z) satisfies the Virozub–Matsaev condition on some interval Δ0 and is boundedly invertible in the endpoints of Δ0, then the ‘embedding’ of the original Hilbert space into the Hilbert space , where the linearization of A(z) acts, is in fact an isomorphism between a subspace of and . As a consequence, properties of the local spectral function of A(z) on Δ0 and a so-called inner linearization of the operator function A(z) in the subspace are established.
相似文献
972.
We propose and compare two classes of convergent finite element based approximations of the nonstationary Nernst–Planck–Poisson
equations, whose constructions are motivated from energy versus entropy decay properties for the limiting system. Solutions
of both schemes converge to weak solutions of the limiting problem for discretization parameters tending to zero. Our main
focus is to study qualitative properties for the different approaches at finite discretization scales, like conservation of
mass, non-negativity, discrete maximum principle, decay of discrete energies, and entropies to study long-time asymptotics. 相似文献
973.
We show that each elation generalized quadrangle with parameters (p, p), where p is a prime, is isomorphic to the symplectic quadrangle W(p) or its dual Q(4, p). Our results cover the more general case of linearly small elation generalized quadrangles. In particular, we obtain a characterization of the symplectic quadrangle over the field of complex numbers among compact connected quadrangles. We prove that every root elation quadrangle (Q, c, H F ) is a skew translation quadrangle. 相似文献
974.
975.
We consider an -hard variant (Δ-Max-ATSP) and an -hard relaxation (Max-3-DCC) of the classical traveling salesman problem. We present a -approximation algorithm for Δ-Max-ATSP and a -approximation algorithm for Max-3-DCC with polynomial running time. The results are obtained via a new way of applying techniques for computing undirected cycle covers to directed problems. 相似文献
976.
Markus Seidel 《Linear algebra and its applications》2009,430(4):1243-1281
We discuss the asymptotic behavior of matrix sequences belonging to a special class of non-commutative Banach algebras and study, in particular, the stability, and more general the Fredholm property of such sequences. The abstract results are applied to finite sections of band-dominated operators, especially in the case lp(Z), 1?p?∞. 相似文献
977.
Markus Mueller 《Linear algebra and its applications》2009,430(4):1292-1312
For multi-input multi-output (MIMO) linear systems with existing vector relative degree a normal form is constructed. This normal form is not only structural simple but allows to characterize the system’s zero dynamics for the design of feedback controllers. A characterization of the zero dynamics in terms of the normal form is given. 相似文献
978.
In the present paper, the aim was to develop a numerical method for optimisation an existing mechanical material model [1] including muscle activation concerning the excitation of skeletal muscles. The modelling idea was a weak and non-monolithic coupling of an electric current expressed by Ohm's law with a hyperelastic muscle model with transversal isotropic characteristics, see [2]. We confirmed the ability of the proposed model by applying on real reconstructed complex muscle geometry. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
979.
Markus Brede 《The Ramanujan Journal》2009,19(3):305-324
Let f be an analytic function in a complex domain D and (without loss of generality) assume 0∈D. Then the paper’s aim is to derive a Taylor-like integral expression for f, i.e. an integral representation analogous to the corresponding power series, say, ∑
k=0∞
a
k
t
k
/k!.
We start from the simplest case f(t)=e
t
, which leads to the identity
valid for Re
t>0, Γ denoting the Euler gamma function. This statement turns out as the result of a summation of the divergent integral ∫
−∞∞
t
y
/Γ(y+1)dy, so that, in the sense of summability, the formula
holds, i.e. a perfect integral analogue of the corresponding series.
Next, we consider the important case of polynomial, resp. monomial f. Then we will apply our statements (on polynomials) to the general case of any function f analytic at 0. Particularly, we will deduce some remarkable statements about the function log (1+x) and its powers, i.e. on the Stirling numbers of the first kind and their generalization to C, the so-called Butzer-Stirling functions. Finally we present a general method for deriving results for large classes of other
functions.
Dedicated to Prof. Dr. Paul L. Butzer, Aachen. 相似文献
980.
Markus Scholle 《PAMM》2011,11(1):693-694
Variational formulations of the governing equations are of great interest in continuum mechanics: on the one hand a deeper theoretical insight in the respective system is possible, on the other hand variational formulations give rise for the development of semi-analytical and numerical methods like Ritz' direct method, especially FEM. Despite these benefits, there are many problems in continuum mechanics for which a variational principle is not available. The reason for this is that in contrast to conservative Newtonian mechanics, where the Lagrangian is given as difference between kinetic and potential energy, no generally valid construction rule for the Lagrangian has been established in the past. In this paper a construction rule is developed, on the Galilei-invariance of the system, leading to a general scheme for Lagrangians the individual analytical form of which is determined by an inverse treatment of Noether's theorem. This procedure is demonstrated for an elastically deforming body. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献