Global ETD Search

31	A high-throughput in-memory index, durable on flash-based SSD: Insights into the winning solution of the SIGMOD programming contest 2011 Kissinger, Thomas, Schlegel, Benjamin, Böhm, Matthias, Habich, Dirk, Lehner, Wolfgang January 2012 (has links) Growing memory capacities and the increasing number of cores on modern hardware enforces the design of new in-memory indexing structures that reduce the number of memory transfers and minimizes the need for locking to allow massive parallel access. However, most applications depend on hard durability constraints requiring a persistent medium like SSDs, which shorten the latency and throughput gap between main memory and hard disks. In this paper, we present our winning solution of the SIGMOD Programming Contest 2011. It consists of an in-memory indexing structure that provides a balanced read/write performance as well as non-blocking reads and single-lock writes. Complementary to this index, we describe an SSD-optimized logging approach to fit hard durability requirements at a high throughput rate. info:eu-repo/classification/ddc/004 ddc:004
32	Exkursion ins Museum der deutschsprachigen Bewohner der böhmischen Länder in Ústí nad Labem (Aussig) Küster, Kerstin, Mallinckrodt, Felicitas von January 2013 (has links) Werden normalerweise neue Museen für bereits bestehende Sammlungen gebaut, so verkehrt sich in Ústí nad Labem dieses Prinzip ins Gegenteil. Auf Initiative des Collegium Bohemicum und unterstützt von der Jan Evangelista Purkyně-Universität Ústí nad Labem wurde 2006 das „Museum für die deutschsprachigen Bewohner der böhmischen Länder“ ins Leben gerufen. Das im Aufbau befindliche Museum hat sich zum Ziel gesetzt, das Wirken und den Beitrag der deutschsprachigen Bewohner in den böhmischen Ländern aus tschechischer Perspektive, aber in europäische Zusammenhänge eingebettet darzustellen und zu vermitteln. (...) info:eu-repo/classification/ddc/020 ddc:020 info:eu-repo/classification/ddc/069 ddc:069
33	Measuring energy consumption for short code paths using RAPL Hähnel, Marcus, Döbel, Björn, Völp, Marcus, Härtig, Hermann 28 May 2013 (has links) Measuring the energy consumption of software components is a major building block for generating models that allow for energy-aware scheduling, accounting and budgeting. Current measurement techniques focus on coarse-grained measurements of application or system events. However, fine grain adjustments in particular in the operating-system kernel and in application-level servers require power profiles at the level of a single software function. Until recently, this appeared to be impossible due to the lacking fine grain resolution and high costs of measurement equipment. In this paper we report on our experience in using the Running Average Power Limit (RAPL) energy sensors available in recent Intel CPUs for measuring energy consumption of short code paths. We investigate the granularity at which RAPL measurements can be performed and discuss practical obstacles that occur when performing these measurements on complex modern CPUs. Furthermore, we demonstrate how to use the RAPL infrastructure to characterize the energy costs for decoding video slices. info:eu-repo/classification/ddc/004 ddc:004
34	Energy-Efficient In-Memory Database Computing Lehner, Wolfgang January 2013 (has links) The efficient and flexible management of large datasets is one of the core requirements of modern business applications. Having access to consistent and up-to-date information is the foundation for operational, tactical, and strategic decision making. Within the last few years, the database community sparked a large number of extremely innovative research projects to push the envelope in the context of modern database system architectures. In this paper, we outline requirements and influencing factors to identify some of the hot research topics in database management systems. We argue that—even after 30 years of active database research—the time is right to rethink some of the core architectural principles and come up with novel approaches to meet the requirements of the next decades in data management. The sheer number of diverse and novel (e.g., scientific) application areas, the existence of modern hardware capabilities, and the need of large data centers to become more energy-efficient will be the drivers for database research in the years to come. info:eu-repo/classification/ddc/004 ddc:004
35	Wireless Interconnect for Board and Chip Level Fettweis, Gerhard P., ul Hassan, Najeeb, Landau, Lukas, Fischer, Erik January 2013 (has links) Electronic systems of the future require a very high bandwidth communications infrastructure within the system. This way the massive amount of compute power which will be available can be inter-connected to realize future powerful advanced electronic systems. Today, electronic inter-connects between 3D chip-stacks, as well as intra-connects within 3D chip-stacks are approaching data rates of 100 Gbit/s soon. Hence, the question to be answered is how to efficiently design the communications infrastructure which will be within electronic systems. Within this paper approaches and results for building this infrastructure for future electronics are addressed. info:eu-repo/classification/ddc/620 ddc:620 info:eu-repo/classification/ddc/621.3 ddc:621.3
36	Waiting for Locks: How Long Does It Usually Take? Baier, Christel, Daum, Marcus, Engel, Benjamin, Härtig, Hermann, Klein, Joachim, Klüppelholz, Sascha, Märcker, Steffen, Tews, Hendrik, Völp, Marcus January 2012 (has links) Reliability of low-level operating-system (OS) code is an indispensable requirement. This includes functional properties from the safety-liveness spectrum, but also quantitative properties stating, e.g., that the average waiting time on locks is sufficiently small or that the energy requirement of a certain system call is below a given threshold with a high probability. This paper reports on our experiences made in a running project where the goal is to apply probabilistic model checking techniques and to align the results of the model checker with measurements to predict quantitative properties of low-level OS code. info:eu-repo/classification/ddc/004 ddc:004
37	Chiefly Symmetric: Results on the Scalability of Probabilistic Model Checking for Operating-System Code Baier, Christel, Daum, Marcus, Engel, Benjamin, Härtig, Hermann, Klein, Joachim, Klüppelholz, Sascha, Märcker, Steffen, Tews, Hendrik, Völp, Marcus January 2012 (has links) Reliability in terms of functional properties from the safety-liveness spectrum is an indispensable requirement of low-level operating-system (OS) code. However, with evermore complex and thus less predictable hardware, quantitative and probabilistic guarantees become more and more important. Probabilistic model checking is one technique to automatically obtain these guarantees. First experiences with the automated quantitative analysis of low-level operating-system code confirm the expectation that the naive probabilistic model checking approach rapidly reaches its limits when increasing the numbers of processes. This paper reports on our work-in-progress to tackle the state explosion problem for low-level OS-code caused by the exponential blow-up of the model size when the number of processes grows. We studied the symmetry reduction approach and carried out our experiments with a simple test-and-test-and-set lock case study as a representative example for a wide range of protocols with natural inter-process dependencies and long-run properties. We quickly see a state-space explosion for scenarios where inter-process dependencies are insignificant. However, once inter-process dependencies dominate the picture models with hundred and more processes can be constructed and analysed. info:eu-repo/classification/ddc/004 ddc:004
38	Secure degrees of freedom on widely linear instantaneous relay-assisted interference channel Ho, Zuleita K.-M., Jorswieck, Eduard January 2013 (has links) The number of secure data streams a relay-assisted interference channel can support has been an intriguing problem. The problem is not solved even for a fundamental scenario with a single antenna at each transmitter, receiver and relay. In this paper, we study the achievable secure degrees of freedom of instantaneous relay-assisted interference channels with real and complex coefficients. The study of secure degrees of freedom with complex coefficients is not a trivial multiuser extension of the scenarios with real channel coefficients as in the case for the degrees of freedom, due to secrecy constraints. We tackle this challenge by jointly designing the improper transmit signals and widely-linear relay processing strategies. info:eu-repo/classification/ddc/621.3 ddc:621.3
39	Interference Leakage Neutralization in Two-Hop Wiretap Channels with Partial CSI Engelmann, Sabrina, Ho, Zuleita K.-M., Jorswieck, Eduard A. January 2013 (has links) In this paper, we analyze the four-node relay wiretap channel, where the relay performs amplify-and-forward. There is no direct link between transmitter and receiver available. The transmitter has multiple antennas, which assist in securing the transmission over both phases. In case of full channel state information (CSI), the transmitter can apply information leakage neutralization in order to prevent the eavesdropper from obtaining any information about the signal sent. This gets more challenging, if the transmitter has only an outdated estimate of the channel from the relay to the eavesdropper. For this case, we optimize the worst case secrecy rate by choosing intelligently the beamforming vectors and the power allocation at the transmitter and the relay. info:eu-repo/classification/ddc/621.3 ddc:621.3
40	Thermo-Energetische Gestaltung von Werkzeugmaschinen: Modellierung und Simulation 19 June 2014 (has links) (PDF) Der Beitrag "Voraussetzungen und Grenzen einer eigenschaftsmodellbasierten Korrektur St. Bäumler, C. Brecher, M. Wennemer; RWTH Aachen, Lehrstuhl für Werkzeugmaschinen" ist in dieser Version nicht enthalten, bitte nutzen Sie die Version unter oben angegebenen Link (Nachfolger). / Im Mittelpunkt der 2. Tagung des Sonderforschungsbereichs Transregio 96 „Thermo-energetische Gestaltung von Werkzeugmaschinen standen erste Ergebnisse zur Modellierung und Simulation von Komponenten und Baugruppen von Werkzeugmaschinen im Mittelpunkt. An den drei Standorten Aachen, Chemnitz und Dresden werden unterschiedliche Lösungsansätze für die steuerungsintegrierte Korrektur thermischer bedingter Strukturverformungen in spanenden Werkzeugmaschinen verfolgt. Von diesen wird eine unterschiedliche Wirksamkeit bzw. Eignung für verschiedene Einsatzfälle erwartet. Bevor diese in der Praxis umgesetzt werden können, müssen Fragen zur Beschreibung der Wärmequellen und zur Wärmeübertragung beantwortet werden. Außerdem bedarf die Umsetzung der Konzepte in den CNC-Steuerungen effizienter Verfahren zur Modellierung und Simulation der thermisch bedingten Strukturverformung. Für die Entwicklung und Bewertung der Korrekturverfahren sowie zur Berechnung der notwendigen Achs-Korrekturen ist die Systemsimulation u. a. an einem prozessaktuelle Werkzeugmaschinenabbild erforderlich. Für die Bewertung ihrer Praxisrelevanz werden die Einzellösungen nach und nach in ein betriebswirtschaftlich orientiertes Gesamtmodell integriert. FE-Modelle Netzwerkknotenmodell Simulation Korrektur Modellierung Fehlerkorrekturen Verlagerungsmessung modellgestützte Beschreibung Wärmeübergangsmechanismen Parametrierung gesteuerter Wärmefluss Parameteridentifikation eigenschaftsmodellbasierte Korrektur kennfeldbasierte Korrektur strukturmodellbasierte Korrektur Collaborative Research Centre network-node-model model heat transfer mechanism error correction correction by characteristic diagram structure model based correction parameter identification ddc:620 rvk:ZL 6100

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