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71.
Minkowski's projection bodies have evolved into Lp projection bodies and their asymmetric analogs. These all turn out to be part of a far larger class of Orlicz projection bodies. The analog of the classical Petty projection inequality is established for the new Orlicz projection bodies. 相似文献
72.
In this paper we establish various existence, nonexistence and multiplicity results for fully nonlinear Dirichlet problems associated to nonlocal Hamilton–Jacobi equations. This study is accomplished by a careful analysis of the principal eigenvalues of the elliptic operator. Resonance phenomena and anti maximum principles are also established. 相似文献
73.
Erwin Hernández Dante Kalise Enrique Otárola 《Computational Optimization and Applications》2010,47(1):161-178
The aim of this work is to obtain optimal-order error estimates for the LQR (Linear-quadratic regulator) problem in a strongly
damped 1-D wave equation. We consider a finite element discretization of the system dynamics and a control law constant in
the spatial dimension, which is studied in both point and distributed case. To solve the LQR problem, we seek a feedback control
which depends on the solution of an algebraic Riccati equation. Optimal error estimates are proved in the framework of the
approximation theory for control of infinite-dimensional systems. Finally, numerical results are presented to illustrate that
the optimal rates of convergence are achieved. 相似文献
74.
Jeroen M. van Oostrum Eelco Bredenhoff Erwin W. Hans 《Annals of Operations Research》2010,178(1):91-104
Operating room (OR) planning and scheduling is a popular and challenging subject within the operational research applied to
health services research (ORAHS). However, the impact in practice is very limited. The organization and culture of a hospital
and the inherent characteristics of its processes impose specific implementation issues that affect the success of planning
approaches. Current tactical OR planning approaches often fail to account for these issues. Master surgical scheduling (MSS)
is a promising approach for hospitals to optimize resource utilization and patient flows. We discuss the pros and cons of
MSS and compare MSS with centralized and decentralized planning approaches. Finally, we address various implementation issues
of MSS and discuss its suitability for hospitals with different organizational foci and culture. 相似文献
75.
Erwin Bolthausen Jean-Dominique Deuschel Uwe Schmock 《Probability Theory and Related Fields》1993,95(3):283-310
Summary We discuss the limiting path measures of Markov processes with either a mean field or a polaron type interaction of the paths. In the polaron type situation the strength is decaying at large distances on the time axis, and so the interaction is of short range in time. In contrast, in the mean field model, the interaction is weak, but of long range in time. Donsker and Varadhan proved that for the partition functions, there is a transition from the polaron type to the mean field interaction when passing to a limit by letting the strength tend to zero while increasing the range. The discussion of the path measures is more subtle. We treat the mean field case as an example of a differentiable interaction and discuss the transition from the polaron type to the mean field interaction for two instructive examples.Research supported by the Swiss National Foundation (21-29833.90)This article was processed by the authors using the Springer-Verlag TEX ProbTh macro package 1991. 相似文献
76.
77.
We present a fully polynomial time approximation scheme (FPTAS) for a capacitated economic lot-sizing problem with a monotone
cost structure. An FPTAS delivers a solution with a given relative error ɛ in time polynomial in the problem size and in 1/ɛ. Such a scheme was developed by van Hoesel and Wagelmans [8] for a capacitated economic lot-sizing problem with monotone
concave (convex) production and backlogging cost functions. We omit concavity and convexity restrictions. Furthermore, we
take advantage of a straightforward dynamic programming algorithm applied to a rounded problem. 相似文献
78.
Flight gate scheduling with respect to a reference schedule 总被引:1,自引:0,他引:1
Ulrich?Dorndorf Florian?Jaehn Erwin?PeschEmail author 《Annals of Operations Research》2012,194(1):177-187
This paper considers the problem of assigning flights to airport gates. We examine the general case in which an aircraft serving
a flight may be assigned to different gates for arrival and departure processing and for optional intermediate parking. Restrictions
to this assignment include gate closures and shadow restrictions, i.e., the situation where certain gate assignments may cause
blocking of neighboring gates. The objectives include maximization of the total assignment preference score, a minimal number
of unassigned flights during overload periods, minimization of the number of tows, maximization of a robustness measure as
well as a minimal deviation from a given reference schedule. We show that in case of a one period time horizon this objective
can easily be integrated into our existing model based on the Clique Partitioning Problem. Furthermore we present a heuristic
algorithm to solve the problem for multiple periods. 相似文献
79.
On the use of Helmholtz resonators as sound attenuators 总被引:1,自引:0,他引:1
Jakob J. Keller Erwin Zauner 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1995,46(3):297-327
Summary In the present paper a nonlinear acoustic theory is proposed, to accurately describe the properties of a generalized type of Helmholtz resonators. The theory may be used as a layout tool to design sound attenuators for combustion facilities. The present investigation shows that, in addition to the nonlinear effects, the effects due to thermoacoustic boundary layers and the first frequency correction to the Helmholtz approximation should be taken into account, in order to predict the frequency-dependent attenuation properties of Helmholtz attenuators with the accuracy required by typical technical applications. A series of experiments is presented which is used to validate the theoretical predictions.
Zusammenfassung In der vorliegenden Abhandlung wird eine nichtlineare akustische Theorie vorgeschlagen, mit der das Verhalten einer verallgemeinerten Art von Helmholtzresonatoren beschrieben werden kann. Die Theorie kann als Werkzeug zur Auslegung von Schalldämpfern für Verbrennungsanlagen benutzt werden. Die vorliegende Arbeit zeigt, dass neben den nichtlinearen Effekten auch die Einflüsse der thermoakustischen Grenzschichten und der ersten Frequenzkorrektur zur Helmholtzapproximation berücksichtigt werden müssen, damit die frequenzabhängigen Eigenschaften von Helmholtzdämpfern mit technisch ausreichender Genauigkeit beschrieben werden können. Mit einer Reihe von Experimenten werden die theoretischen Ergebnisse untermauert.相似文献
80.
In this article we study various convergence results for a class of nonlinear fractional heat equations of the form $\left\{ \begin{gathered} u_t (t,x) - \mathcal{I}[u(t, \cdot )](x) = f(t,x),(t,x) \in (0,T) \times \mathbb{R}^n , \hfill \\ u(0,x) = u_0 (x),x \in \mathbb{R}^n , \hfill \\ \end{gathered} \right.$ where I is a nonlocal nonlinear operator of Isaacs type. Our aim is to study the convergence of solutions when the order of the operator changes in various ways. In particular, we consider zero order operators approaching fractional operators through scaling and fractional operators of decreasing order approaching zero order operators. We further give rate of convergence in cases when the solution of the limiting equation has appropriate regularity assumptions. 相似文献