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231.
Feng Luo Saul Schleimer Stephan Tillmann 《Proceedings of the American Mathematical Society》2008,136(7):2625-2630
It is shown that every non-compact hyperbolic manifold of finite volume has a finite cover admitting a geodesic ideal triangulation. Also, every hyperbolic manifold of finite volume with non-empty, totally geodesic boundary has a finite regular cover which has a geodesic partially truncated triangulation. The proofs use an extension of a result due to Long and Niblo concerning the separability of peripheral subgroups.
232.
Scheduling algorithms and their role in supply chain planning are topics that have been discussed in scheduling literature
for many years. Based on examples and experience with commercial supply chain planning software, this paper presents background
information about production planning and scheduling functionality in commercial supply chain planning software and interesting
scheduling coordination problems in supply chain planning for researchers. We first provide an overview of different planning
activities in supply chain planning, while taking into consideration existing functionalities that are available in commercial
supply chain planning software. As a second step, we show three scheduling coordination problems in supply chain planning,
namely the integration of production planning and production scheduling, the integration of sales order confirmation and production
scheduling and the integration of VMI planning and production scheduling. We conclude this paper with a detailed discussion
of an implementation of a supply chain planning solution at the tissue producer SCA Hygiene in Sweden.
This paper expresses the authors opinion and does not represent an official statement from SAP. 相似文献
233.
Stephan Matos Camacho 《Discrete Mathematics》2009,309(15):4916-4919
In 1992 Gyárfás showed that a graph G having only k odd cycle lengths is (2k+1)-colourable, if it does not contain a K2k+2. In this paper, we will present the results for graphs containing only odd cycles of length 2m−1 and 2m+1 as done in [S. Matos Camacho, Colourings of graph with prescribed cycle lengths, diploma thesis, TU Bergakademie Freiberg, 2006. [3]]. We will show that these graphs are 4-colourable. 相似文献
234.
Universally prestarlike functions (of order α ≤ 1) in the slit domain
L:=\mathbbC\[1,¥]{\Lambda:=\mathbb{C}{\setminus}[1,\infty]} have recently been introduced in Ruscheweyh et al. (Israel J Math, to appear). This notation generalizes the corresponding
one for functions in the unit disk
\mathbbD{\mathbb{D}} (and other circular domains in
\mathbbC{\mathbb{C}}). In this paper we study the behaviour of universally prestarlike functions under the Hadamard product. In particular it
is shown that these function classes (with α fixed), are closed under convolution, and that their members, as Hadamard multipliers, also preserve the prestarlikeness
(of the same order) of functions in arbitrary circular domains containing the origin. 相似文献
235.
Andrii Khrabustovskyi Holger Stephan 《Mathematical Methods in the Applied Sciences》2008,31(15):1809-1834
We consider a general linear reaction–diffusion system in three dimensions and time, containing diffusion (local interaction), jumps (nonlocal interaction) and memory effects. We prove a maximum principle and positivity of the solution and investigate its asymptotic behavior. Moreover, we give an explicit expression of the limit of the solution for large times. In order to obtain these results, we use the following method: We construct a Riemannian manifold with complicated microstructure depending on a small parameter. We study the asymptotic behavior of the solution to a simple diffusion equation on this manifold as the small parameter tends to zero. It turns out that the homogenized system coincides with the original reaction–diffusion system. Using this and the facts that the diffusion equation on manifolds satisfies the maximum principle and its solution converges to a easily calculated constant, we can obtain analogous properties for the original system. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
236.
In many practical optimization problems, evaluation of a solution is subject to noise, e.g., due to stochastic simulations
or measuring errors. Therefore, heuristics are needed that are capable of handling such noise. This paper first reviews the
state-of-the-art in applying simulated annealing to noisy optimization problems. Then, two new algorithmic variants are proposed:
an improved version of stochastic annealing that allows for arbitrary annealing schedules, and a new approach called simulated annealing in noisy environments (SANE). The latter integrates ideas from statistical sequential selection in order to reduce the number of samples required
for making an acceptance decision with sufficient statistical confidence. Finally, SANE is shown to significantly outperform
other state-of-the-art simulated annealing techniques on a stochastic travelling salesperson problem. 相似文献
237.
Ernst P. Stephan 《Mathematische Nachrichten》1987,134(1):21-53
Both exterior and interior mixed Dirichlet-Neumann problems in R3 for the scalar Helmholtz equation are solved via boundary integral equations. The integral equations are equivalent to the original problem in the sense that the traces of the weak seolution satisfy the integral equations, and, conversely, the solution of the integral equations inserted into Green's formula yields the solution of the mixed boundary value problem. The calculus of pseudodifferential operators is used to prove existence and regularity of the solution of the integral equations. The regularity results — obtained via Wiener-Hopf technique — show the explicit “edge” behavior of the solution near the submanifold which separates the Dirichlet boundary from the Neumann boundary. 相似文献
238.
Summary We study Vandermonde matrices whose nodes are given by a Van der Corput sequence on the unit circle. Our primary interest is in the singular values of these matrices and the respective (spectral) condition numbers. Detailed information about multiplicities and eigenvectors, however, is also obtained. Two applications are given to the theory of polynomials.Dedicated to R. S. Varga on the occasion of his sixtieth birthdayResearch of A. C. supported by the Fundación Andes, Chile, and by the German Academic Exchange Service (DAAD), Federal Republic of GermanyResearch of W. G. supported, in part, by the National Science Foundation, USA, (Grant CCR-8704404)Research of S. R. supported by the Fondo Nacional de Desarollo Cientßfico y Tecnológico (FONDECYT), Chile, (Grant 237/89), by the Universidad Técnica F. Santa Marßa, Valparaßso, Chile, (Grant 89.12.06), and by the German Academic Exchange Service (DAAD), Federal Republic of Germany 相似文献
239.
Dennis Dittrich Heiko Tewes Christoph Wölper Dieter Bläser Stephan Schulz Joachim Roll 《Transition Metal Chemistry》2017,42(3):237-241
Reaction of [Zn4(µ4-O)(O2CCH3)6] with one equivalent of 4-tertiary-butylpyridine leads to a nearly quantitative formation of the heptanuclear cluster [Zn7O2(O2CCH3)10(tbupy)2] (1). Here, we present the crystal structure of 1 and first results of the examination of its catalytic activity in transesterification reactions and polymerization of lactide compared to the activity of [Zn4(µ4-O)(O2CCH3)6] in the presence of 4-tertiary-butylpyridine. 相似文献
240.
Clarissa Müller Tim Ortmann Akram Abi Dave Hartig Stephan Scholl Hans-Joachim Jördening 《Applied biochemistry and biotechnology》2017,182(1):197-215
Immobilization methods and carriers were screened for immobilization of Euglena gracilis extract with laminaribiose phosphorylase activity. The extract was successfully immobilized on three different carriers via covalent linkage. Suitable immobilization carriers were Sepabeads EC-EP/S and ECR 8209M with epoxy groups and ECR 8309M with amino groups as functional units. Immobilization on Sepabeads EC-EP/S resulted in highest retained activity (65%). The immobilizates were characterized for pH, temperature, and buffer molarity preferences. The immobilized enzyme lost 48% of its activity when used seven times. Together with sucrose phosphorylase, laminaribiose phosphorylase was successfully applied for bienzymatic production of laminaribiose from sucrose and glucose with a final laminaribiose concentration of 14.3 ± 2.1 g/L (20% yield). 相似文献