TY - GEN A1 - Schäfer, Patrick T1 - Bag-Of-SFA-Symbols in Vector Space (BOSS VS) N2 - Time series classification mimics the human understanding of similarity. When it comes to larger datasets, state of the art classifiers reach their limits in terms of unreasonable training or testing times. One representative example is the 1-nearest-neighbor DTW classifier (1-NN DTW) that is commonly used as the benchmark to compare to and has several shortcomings: it has a quadratic time and it degenerates in the presence of noise. To reduce the computational complexity lower bounding techniques or recently a nearest centroid classifier have been introduced. Still, execution times to classify moderately sized datasets on a single core are in the order of hours. We present our Bag-Of-SFA-Symbols in Vector Space (BOSS VS) classifier that is robust and accurate due to invariance to noise, phase shifts, offsets, amplitudes and occlusions. We show that it is as accurate while being multiple orders of magnitude faster than state of the art classifiers. Using the BOSS VS allows for mining massive time series datasets and real-time analytics. T3 - ZIB-Report - 15-30 KW - Time Series KW - Classification KW - Data Mining Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-54984 SN - 1438-0064 ER - TY - GEN A1 - Taentzer, Gabriele A1 - Golas, Ulrike T1 - Local Confluence Analysis for Amalgamated Graph Transformation: Long Version N2 - Amalgamated graph transformation allows to define schemes of rules coinciding in common core activities and differing over additional parallel independent activities. Consequently, a rule scheme is specified by a kernel rule and a set of extending multi-rules forming an interaction scheme. Amalgamated transformations have been increasingly used in various modeling contexts. Critical Pair Analysis (CPA) can be used to show local confluence of graph transformation systems. It is an open challenge to lift the CPA to amalgamated graph transformation systems, especially since infinite many pairs of amalgamated rules occur in general. As a first step towards an efficient local confluence analysis of amalgamated graph transformation systems, we show that the analysis of a finite set of critical pairs suffices to prove local confluence. T3 - ZIB-Report - 15-29 KW - amalgamated graph transformation KW - parallel independence KW - critical pair analysis Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-54943 SN - 1438-0064 ER - TY - GEN A1 - Wende, Florian T1 - SIMD Enabled Functions on Intel Xeon CPU and Intel Xeon Phi Coprocessor N2 - To achieve high floating point compute performance, modern processors draw on short vector SIMD units, as found e.g. in Intel CPUs (SSE, AVX1, AVX2 as well as AVX-512 on the roadmap) and the Intel Xeon Phi coprocessor, to operate an increasingly larger number of operands simultaneously. Making use of SIMD vector operations therefore is essential to get close to the processor’s floating point peak performance. Two approaches are typically used by programmers to utilize the vector units: compiler driven vectorization via directives and code annotations, and manual vectorization by means of SIMD intrinsic operations or assembly. In this paper, we investigate the capabilities of the current Intel compiler (version 15 and later) to generate vector code for non-trivial coding patterns within loops. Beside the more or less uniform data-parallel standard loops or loop nests, which are typical candidates for SIMDfication, the occurrence of e.g. (conditional) function calls including branching, and early returns from functions may pose difficulties regarding the effective use of vector operations. Recent improvements of the compiler's capabilities involve the generation of SIMD-enabled functions. We will study the effectiveness of the vector code generated by the compiler by comparing it against hand-coded intrinsics versions of different kinds of functions that are invoked within innermost loops. T3 - ZIB-Report - 15-17 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-54163 SN - 1438-0064 ER - TY - GEN A1 - Wende, Florian A1 - Steinke, Thomas A1 - Reinefeld, Alexander T1 - The Impact of Process Placement and Oversubscription on Application Performance: A Case Study for Exascale Computing N2 - With the growing number of hardware components and the increasing software complexity in the upcoming exascale computers, system failures will become the norm rather than an exception for long-running applications. Fault-tolerance can be achieved by the creation of checkpoints during the execution of a parallel program. Checkpoint/Restart (C/R) mechanisms allow for both task migration (even if there were no hardware faults) and restarting of tasks after the occurrence of hardware faults. Affected tasks are then migrated to other nodes which may result in unfortunate process placement and/or oversubscription of compute resources. In this paper we analyze the impact of unfortunate process placement and oversubscription of compute resources on the performance and scalability of two typical HPC application workloads, CP2K and MOM5. Results are given for a Cray XC30/40 with Aries dragonfly topology. Our results indicate that unfortunate process placement has only little negative impact while oversubscription substantially degrades the performance. The latter might be only (partially) beneficial when placing multiple applications with different computational characteristics on the same node. T3 - ZIB-Report - 15-05 KW - Fault-tolerance KW - Process placement KW - Oversubscription Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-53560 SN - 1438-0064 ER -