Pathways to servers of the future

The Special Session on “Pathways to Servers of the Future” outlines a new research program set up at Technische Universität Dresden addressing the increasing energy demand of global internet usage and the resulting ecological impact of it. The program pursues a novel holistic approach that considers hardware as well as software adaptivity to significantly increase energy efficiency, while suitably addressing application demands. The session presents the research challenges and industry perspective

Disorder effects in cellular automata for two-lane traffic

For single-lane traffic models it is well known that particle disorder leads to platoon formation at low densities. Here we discuss the effect of slow cars in two-lane systems. Surprisingly, even a small number of slow cars can initiate the formation of platoons at low densities. The robustness of this phenomenon is investigated for different variants of the lane-changing rules as well as for different variants on the single-lane dynamics. It is shown that anticipation of drivers reduces the influence of slow cars drastically.Comment: RevTeX, 22 eps-figures included, 10 page

Per Aspera ad Astra: On the Way to Parallel Processing

Computational Science and Engineering is being established as a third category of scientific methodology; this innovative discipline supports and supplements the traditional categories: theory and experiment, in order to solve the problems arising from complex systems challenging science and technology. While the successes of the past two decades in scientific computing have been achieved essentially by the technical breakthrough of the vector-supercomputers, today the discussion about the future of supercomputing is focussed on massively parallel computers. The discrepancy, however, between peak performance and sustained performance achievable with algorithmic kernels, software packages, and real applications is still disappointingly high. An important issue are programming models. While Message Passing on parallel computers with distributed memory is the only efficient programming paradigm available today, from a user's point of view it is hard to imagine that this programming model, rather than Shared Virtual Memory, will be capable to serve as the central basis in order to bring computing on massively parallel systems from a sheer computer science trend to the technological breakthrough needed to deal with the large applications of the future; this is especially true for commercial applications where explicit programming the data communication via Message Passing may turn out to be a huge software-technological barrier which nobody might be willing to surmount.KFA Jülich is one of the largest big-science research centres in Europe; its scientific and engineering activities are ranging from fundamental research to applied science and technology. KFA's Central Institute for Applied Mathematics (ZAM) is running the large-scale computing facilities and network systems at KFA and is providing communication services, general-purpose and supercomputer capacity also to the HLRZ ("Höchstleistungsrechenzentrum") established in 1987 in order to further enhance and promote computational science in Germany. Thus, at KFA - and in particular enforced by ZAM - supercomputing has received high priority since more than ten years. What particle accelerators mean to experimental physics, supercomputers mean to Computational Science and Engineering: Supercomputers are the accelerators of theory

Metallorganische Lewissäuren. Metallkomplexe mit schwach koordinierten Liganden

Die Umsetzung der Tetrafluoroborato-Komplexe (η5-C5H5)(CO)2(L)MoFBF3 mit verschiedenen Alkinen liefert Mono- und Bis-Alkin-Komplexe [(η5-C5H5)-Mo(CO)(RCCR′)2]+BF4−(III) und [(η5-C5H5)Mo(CO)(L)(RCCR′)]+BF4−(IV) (L = CO, P(OPh)3, PEt3; R = R′ = H, Me, Ph; R = H, R′ = Ph). Der Anteil von III bzw. IV im Produktgemisch ist abhängig von der Natur von L und der des eingesetzten Alkins. Die Struktur von [(η5-C5H5)Mo(CO)L(RCCR′)]+BF4− wurde röntgenographisch bestimmt

Metallorganische Lewissäuren. Metallkomplexe mit schwach koordinierten anionischen Liganden

Durch Umsetzung von (π-C5H5)(CO)3MoX (X− = BF4−, SbF6−) mit (π-C5H5)(CO)3MoCH2Ph bzw. (π-C5H5)(CO)2FeCH3 wurden die acylverbrückten Komplexe [(π-C5H5)(CO)2Mo(μ2-, η2-COCH2Ph)Mo(CO)2(π-C5H5)]+ BF4− (2b) und [(π-C5H5)(CO)2Fe(μ2-, η1-COCH3)Mo(CO)3(π-C5H5)]+ SbF6− (4) erhalten. Die Röntgenstruktur von 4 wurde bestimmt. Bei der Reaktion von (π-C5H5)(CO)3MoFBF3 mit (CO)5MCH3 (M = Mn, Re) erfolgt Hydrid- und Methylübertragung unter Bildung der Verbindungen (π-C5H5)(CO)3MoCH3, (CO)5MFBF3 und {[(π-C5H5)(CO)3Mo]2H}+ BF4−. (π-C5H5)(CO)3MoFBF3 und (π-C5H5)Co(CO)2) liefern ein 1:1-Addukt, während bei der Umsetzung von (π-C5H5)(CO)3MoX (X− = BF4−, PF6−, AsF6−, SbF6−) mit den Metallocenen M(π-C5H5)2 (M = Co, Ni) Redoxreaktionen auftreten

Grid-Computing

"Grid-Computing", ein Mitte der 90er Jahre eingeführter Begriff, bezeichnet eine Architektur für verteilte Systeme, die auf dem World Wide Web aufbaut und die Web-Vision erweitert. Mit dem Grid-Computing werden die Ressourcen einer Gemeinschaft, einer sogenannten “virtuellen Organisation” (siehe unten), integriert. Die Hoffnung ist, dass hierdurch rechen- und/oder datenintensiven Aufgaben, die eine einzelne Organisation nicht lösen kann, handhabbar werden. Ein “Grid” bezeichnet eine nach dem Grid-Computing-Ansatz aufgebaute Rechner-, Netzwerk- und Software-Infrastruktur zur Teilung von Ressourcen mit dem Ziel, die Aufgaben einer virtuellen Organisation zu erledigen. Zu Beginn war die Möglichkeit, ungenutzte CPU-Ressourcen an anderen Stellen für die eigenen Aufgaben einzusetzen, die wesentlich treibende Kraft für erste Experimente. Internet-Computing-Projekte wie SETI@Home, distributed.net u.a., bei denen die unbenutzten Rechenzyklen von weltweit verteilten privaten PCs verwendet werden, illustrieren das Potential des Grid-Computing. Die heutigen Grid-Konzepte und die ersten -Prototypen gehen weit über diese Anfänge hinaus. Sie versprechen die transparente Bereitstellung von Diensten unabhängig von der räumlichen Nähe. Es wird erwartet, dass das Grid-Computing die Nutzung von Rechnern und Rechnernetzen so grundlegend verändern wird, wie das Web den Datenaustausch bereits verändert hat

Turning Privacy Constraints into Syslog Analysis Advantage

Nowadays, failures in high performance computers (HPC) became the norm rather than the exception [10]. In the near future, the mean time between failures (MTBF) of HPC systems is expected to be too short, and that current failure recovery mechanisms e.g., checkpoint-restart, will no longer be able to recover the systems from failures [1]. Early fail- ure detection is a new class of failure recovery methods that can be beneficial for HPC systems with short MTBF. De- tecting failures in their early stage can reduce their negative effects by preventing their propagation to other parts of the system [3]. The goal of the current work is to contribute to the foun- dation of failure detection techniques via sharing an ongo- ing research with the community. Herein we consider user privacy as the main priority, and then turning the applied constraint for protecting users privacy into an advantage for analyzing the system behavior. We use De-identification, constantification, and hashing to reach this goal. Our ap- proach also contributes to the reproducibility and openness of future research in the field. Via this approach, system ad- ministrators can unwarily share their syslogs with the public domain

Performance-Analyse paralleler Programme: Die PARvis-Visualisierungsumgebung

PARvis ist eine Visualisierungsumgebung, die eine gegebene Trace-Datei in eine Reihe verschiedener graphischer Darstellungen, z.B. Momentaufnahmen, Statistiken oder auch Zeitachsendarstellungen, transferiert. Dies erleichtert die Programmoptimierung, wodurch der Entwicklungszyklus auf massiv-parallelen Rechnersystemen deutlich verkürzt wird. PARvis unterstützt die gängigen Programmiermodelle (physikalisch/virtuell gemeinsamer Speicher, Message-Passing) und ist auf einer breiten Palette von Workstations ablauffähig

Measurements of complement factor H-related protein (BTA-TRAK (TM) assay) and nuclear matrix protein (NMP22 assay) - Useful diagnostic tools in the diagnosis of urinary bladder cancer?

Between 1997 and 2000 we investigated in a prospective study the voided urine samples of all consecutive patients undergoing cystoscopy independent from their clinical background (n=705) with the BTA-TRAK(TM) assay (Bard Diagnostics, Redmont, USA) detecting complement factor H-related protein (CFHrP) and the NMP22 assay (Matritech, Newton, USA) measuring nuclear matrix protein, which is supposed to be specific for bladder cancer. The individuals were divided into three groups concerning the clinical background: 233 patients had urological diseases, 268 patients had urinary bladder cancer and 150 patients had other urological malignancies. Based on the clinical findings we compared our results with well established diagnostic methods for urinary bladder cancer such as cytology and the detection of hematuria. In addition, we investigated urine samples from 30 healthy individuals and 24 patients with urinary tract infection without performing cystoscopy. Following the recommendations of the European Group on Tumor Markers we used 95% specificity for benign urological diseases and urinary tract infections, which resulted in a sensitivity of 17% for active bladder cancer for the BTA-TRAK(TM) assay and 31% for NMP22. We compared these results with the detection of hematuria (specificity: 72%) and cytology, which had a sensitivity of 64% and 89%, respectively. Subsequently, we calculated sensitivity and specificity for the detection of relapse of the disease. Again using 95% specificity, in this case for patients with no evidence of disease (NED), in patients with recurrent disease the BTA-TRAK(TM) assay showed % sensitivity as compared to 12% for the NMP22 assay. Due to an insufficient specificity and sensitivity, both tests can neither be clinically useful in screening of high risk patients, nor in primary diagnosis of bladder cancer. They cannot replace neither cystoscopy nor cytology. In the follow-up care more investigations may be necessary to prove the benefit of existing diagnostic strategies for the discrimination between active and inactive bladder cancer

Linux Cluster in Theory and Practice: A Novel Approach in Teaching Cluster Computing Based on the Intel Atom Platform

AbstractCurrent trends and studies on future architectures show, that the complexity of parallel computer systems is increasing steadily. Hence, the industry requires skilled employees, who have in addition to the theoretical fundamentals, practical experiences in the design and administration of such systems. However, investigations have shown, that practical approaches are still missing in current curricula, especially in these areas. For this reason, the chair of Computer Architecture at the faculty of Computer Science at the Technische Universiẗat Dresden, developed and introduced the course “Linux Cluster in Theory and Practice” (LCTP). The main objectives of this course are to provide background knowledge about the design and administration of large-scale parallel computer systems and the practical implementation on the available hardware. In addition, students learn how to solve problems in a structured approach and as part of a team. This paper analyzes the current variety of courses in the area of parallel computing systems, describes the structure and implementation of LCTP and provides first conclusions and an outlook on possible further developments