TY - JOUR A1 - Kling, Christoph A1 - Schneidenbach, Lars A1 - Schnor, Bettina T1 - A high performance gigabit ethernet messaging method for PVFS N2 - Parallel File Systems like PVFS2 are a necessary compo nent for high-performance computing. The design of ef ;cient communication layers for these systems is still of great research interest. This paper presents a low- latency messaging method for PVFS2 dedicated for Gigabit Ether net networks and discusses relevant design issues. In con trast to other approaches, we argue that zero-copying can be achieved also for big messages without use of a rendez vous protocol. Further, ef;ciency within the communica tion layer like a small call stack plays an important role. Y1 - 2005 SN - 0-88986-525-6 ER - TY - JOUR A1 - Rasch, T. A1 - Schindler, R. T1 - A new condensation principle N2 - We generalize del(A), which was introduced in [Schinfinity], to larger cardinals. For a regular cardinal kappa>N-0 we denote by del(kappa)(A) the statement that Asubset of or equal tokappa and for all regular theta>kappa(o), {X is an element of[L-theta[A]](<) : X &AND; &ISIN; &AND; otp (X &AND; Ord) &ISIN; Card (L[A&AND;X&AND;])} is stationary in [L-[A]](<). It was shown in [Sch&INFIN;] that &DEL;(N1) (A) can hold in a set-generic extension of L. We here prove that &DEL;(N2) (A) can hold in a set-generic extension of L as well. In both cases we in fact get equiconsistency theorems. This strengthens results of [Ra00] and [Ran01]. &DEL;(N3) () is equivalent with the existence of 0# Y1 - 2005 SN - 1432-0665 ER - TY - JOUR A1 - Gunther, U. A1 - Zhuk, Alexandre A1 - Bezerra, Valdir B. A1 - Romero, C. T1 - AdS and stabilized extra dimensions in multi-dimensional gravitational models with nonlinear scalar curvature terms R-1 and R-4 N2 - We study multi-dimensional gravitational models with scalar curvature nonlinearities of types R-1 and R-4. It is assumed that the corresponding higher dimensional spacetime manifolds undergo a spontaneous compactification to manifolds with a warped product structure. Special attention has been paid to the stability of the extra-dimensional factor spaces. It is shown that for certain parameter regions the systems allow for a freezing stabilization of these spaces. In particular, we find for the R-1 model that configurations with stabilized extra dimensions do not provide a late-time Acceleration (they are AdS), whereas the solution branch which allows. for accelerated expansion (the dS branch) is incompatible with stabilized factor spaces. In the case of the R-4 model, we obtain that the stability region in parameter space depends on the total dimension D = dim(M) of the higher dimensional spacetime M. Tor D > 8 the stability region consists of a single (absolutely stable) sector which is shielded from a conformal singularity (and an antigravity sector beyond it) by a potential barrier of infinite height and width. This sector is smoothly connected with the stability region of a curvature-linear model. For D < 8 an additional (metastable) sector exists Which is separated from the conformal singularity by a potential barrier of finite height and width so that systems in this sector are prone to collapse into the conformal singularity. This second sector is not smoothly connected with the first (absolutely stable) one. Several limiting cases and the possibility of inflation are discussed for the R-4 model Y1 - 2005 SN - 0264-9381 ER - TY - JOUR A1 - Baake, Ellen A1 - Baake, Michael A1 - Bovier, Anton A1 - Klein, Markus T1 - An asymptotic maximum principle for essentially linear evolution models N2 - Recent work on mutation-selection models has revealed that, under specific assumptions on the fitness function and the mutation rates, asymptotic estimates for the leading eigenvalue of the mutation-reproduction matrix may be obtained through a low-dimensional maximum principle in the limit N --> infinity (where N, or N-d with d greater than or equal to 1, is proportional to the number of types). In order to extend this variational principle to a larger class of models, we consider here a family of reversible matrices of asymptotic dimension N-d and identify conditions under which the high-dimensional Rayleigh-Ritz variational problem may be reduced to a low-dimensional one that yields the leading eigenvalue up to an error term of order 1/N. For a large class of mutation-selection models, this implies estimates for the mean fitness, as well as a concentration result for the ancestral distribution of types Y1 - 2005 SN - 0303-6812 ER - TY - BOOK A1 - Fang, Daoyuan A1 - Xu, Jiang T1 - Asymptotic behavior of solutions to multidimensional nonisentropic hydrodynamic model for semiconductors T3 - Preprint / Universität Potsdam, Institut für Mathematik, Arbeitsgruppe Partiell Y1 - 2005 SN - 1437-739X PB - Univ. CY - Potsdam ER - TY - INPR A1 - Fang, Daoyuan A1 - Xu, Jiang T1 - Asymptotic behavior of solutions to multidimensional nonisentropic hydrodynamic model for semiconductors N2 - In this paper, a global existence result of smooth solutions to the multidimen- sional nonisentropic hydrodynamic model for semiconductors is proved, under the assumption that the initial data is a perturbation of the stationary solutions for the thermal equilibrium state. The resulting evolutionary solutions converge to the stationary solutions in time asymptotically exponentially fast. T3 - Preprint - (2005) 02 KW - Multidimensional nonisentropic hydrodynamic model KW - semiconductors KW - asymptotic behavior KW - global solutions Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-29767 ER - TY - JOUR A1 - Harutjunjan, Gohar A1 - Schulze, Bert-Wolfgang T1 - Boundary problems with meromorphic symbols in cylindrical domains N2 - We show relative index formulas for boundary value problems in cylindrical domains and Sobolev spaces with different weights at too. The amplitude functions are meromorphic in the axial covariable and take values in the space of boundary value problems on the cross section of the cylinder. Copyright (c) 2005 John Wiley & Sons, Ltd Y1 - 2005 SN - 0170-4214 ER - TY - JOUR A1 - Savin, Anton A1 - Sternin, Boris T1 - Boundary value problems on manifolds with fibered boundary N2 - We define a class of boundary value problems on manifolds with fibered boundary. This class is in a certain sense a deformation between the classical boundary value problems and the Atiyah-Patodi-Singer problems in subspaces (it contains both as special cases). The boundary conditions in this theory are taken as elements of the C*-algebra generated by pseudodifferential operators and families of pseudodifferential operators in the fibers. We prove the Fredholm. property for elliptic boundary value problems and compute a topological obstruction (similar to Atiyah-Bott obstruction) to the existence of elliptic boundary conditions for a given elliptic operator. Geometric operators with trivial and nontrivial obstruction are given. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Y1 - 2005 SN - 0025-584X ER - TY - INPR A1 - Schulze, Bert-Wolfgang A1 - Tarkhanov, Nikolai Nikolaevich T1 - Boundary value problems with Toeplitz conditions N2 - We describe a new algebra of boundary value problems which contains Lopatinskii elliptic as well as Toeplitz type conditions. These latter are necessary, if an analogue of the Atiyah-Bott obstruction does not vanish. Every elliptic operator is proved to admit up to a stabilisation elliptic conditions of such a kind. Corresponding boundary value problems are then Fredholm in adequate scales of spaces. The crucial novelty consists of the new type of weighted Sobolev spaces which serve as domains of pseudodifferential operators and which fit well to the nature of operators. T3 - Preprint - (2005) 08 KW - Pseudodifferential operators KW - boundary values problems KW - Toeplitz operators Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-29837 ER - TY - JOUR A1 - Kapanadze, David A1 - Schulze, Bert-Wolfgang T1 - Boundary-contact problems for domains with conical singularities N2 - We study boundary-contact problems for elliptic equations (and systems) with interfaces that have conical singularities. Such problems represent continuous operators between weighted Sobolev spaces and subspaces with asymptotics. Ellipticity is formulated in terms of extra transmission conditions along the interfaces with a control of the conormal symbolic structure near conical singularities. We show regularity and asymptotics of solutions in weighted spaces, and we construct parametrices. The result will be illustrated by a number of explicit examples. (c) 2004 Elsevier Inc. All rights reserved Y1 - 2005 SN - 0022-0396 ER -