TY - CHAP A1 - Grammel, Martin A1 - Back, Godmar A1 - Wunderling, Roland A1 - Hege, Hans-Christian T1 - Ein paralleles C++/C-Programmiermodell für ein objektorientiertes B&C-Framework T2 - GI/ITG-Workshop, Sept.1994, Mitteilungen der Fachgruppe PARS der Gesellschaft für Informatik (GI) Y1 - 1994 VL - 13 SP - 50 EP - 59 CY - Potsdam ER - TY - GEN A1 - Grammel, Martin A1 - Hege, Hans-Christian A1 - Wunderling, Roland T1 - On the Impact of Communication Latencies on Distributed Sparse LU Factorization. N2 - Sparse LU factorization offers some potential for parallelism, but at a level of very fine granularity. However, most current distributed memory MIMD architectures have too high communication latencies for exploiting all parallelism available. To cope with this, latencies must be avoided by coarsening the granularity and by message fusion. However, both techniques limit the concurrency, thereby reducing the scalability. In this paper, an implementation of a parallel LU decomposition algorithm for linear programming bases is presented for distributed memory parallel computers with noticable communication latencies. Several design decisions due to latencies, including data distribution and load balancing techniques, are discussed. An approximate performance model is set up for the algorithm, which allows to quantify the impact of latencies on its performance. Finally, experimental results for an Intel iPSC/860 parallel computer are reported and discussed. T3 - ZIB-Report - SC-93-28 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-1245 ER - TY - THES A1 - Wunderling, Roland T1 - Paralleler und objektorientierter Simplex-Algorithmus Y1 - 1996 ER - TY - CHAP A1 - Wunderling, Roland A1 - Grammel, Martin A1 - Hege, Hans-Christian T1 - Parallele LU-Zerlegung großer, unsymmetrischer, dünn besetzter Matrizen bei hohen Kommunikationslatenzen T2 - GI/ITG-Workshop, Sept.1994, Mitteilungen der Fachgruppe PARS der Gesellschaft für Informatik (GI) Y1 - 1994 VL - 13 SP - 191 EP - 200 CY - Potsdam ER - TY - GEN A1 - Wunderling, Roland A1 - Hege, Hans-Christian T1 - AGIL - the Adaptable Graphical Interface Layer, Programmierer-Handbuch Y1 - 1992 SP - 34pp. PB - Interner Report, Konrad-Zuse-Zentrum für Informationstechnik Berlin (ZIB), Germany ER -