Durch das Forschungszentrum Rossendorf wurde in den Jahren 1996-1998 ein eigenes Strahlrohr fuer Experimente mit Synchrotronstrahlung an der ESRF (European Synchrotron Radioation Facility) in Grenoble/Frankreich aufgebaut. Das Strahlrohr verfuegt ueber zwei alternativ nutzbare Messplaetze fuer die Untersuchung von radioaktiven Proben mittels Roentgenabsorptionsspektroskopie und fuer Materialstrukturuntersuchungen mit Roentgendiffraktion. Der Bericht konzentriert sich auf die Arbeiten, die fuer die Steuerung der Optik und die Nutzung der Messplaetze hinsichtlich der Elektronik, Rechentechnik und Software erforderlich waren. Nach einer Beschreibung der Randbedingungen und einer Kurzcharakteristik der geraetetechnischen Basis werden wichtige Hardwarekomponenten fuer die Instrumentierung der Systeme vorgestellt. Die rechentechnische Basis wird anschliessend beschrieben. Die angewendeten Software-Grundprinzipien werden erlaeutert und diskutiert sowie an einigen Applikationen beispielhaft verdeutlicht. Abschliessend werden spezifische Probleme bei der Programmierung von Applikationen mit grafischer Bedienoberflaeche in Verbindung mit Geraetezugriffen behandelt. Tabellen, in denen die benutzten Hardware-Module und die Softwarekomponenten zusammengestellt sind, ermoeglichen einen Ueberblick ueber das Gesamtsystem. Das Literaturverzeichnis dient als Leitfaden fuer die Detaildokumentationen.

The MPI_Barrier-collective operation, as a part of the MPI-1.1 standard, is extremely important for all parallel applications using it. The latency of this operation increases the application run time and can not be overlaid. Thus, the whole MPI performance can be decreased by unsatisfactory barrier latency. The main goals of this work are to lower the barrier latency for InfiniBand networks by analyzing well known barrier algorithms with regards to their suitability within InfiniBand networks, to enhance the barrier operation by utilizing standard InfiniBand operations as much as possible, and to design a constant time barrier for InfiniBand with special hardware support. This partition into three main steps is retained throughout the whole thesis. The first part evaluates publicly known models and proposes a new more accurate model (LoP) for InfiniBand. All barrier algorithms are evaluated within the well known LogP and this new model. Two new algorithms which promise a better performance have been developed. A constant time barrier integrated into InfiniBand as well as a cheap separate barrier network is proposed in the hardware section. All results have been implemented inside the Open MPI framework. This work led to three new Open MPI collective modules. The first one implements different barrier algorithms which are dynamically benchmarked and selected during the startup phase to maximize the performance. The second one offers a special barrier implementation for InfiniBand with RDMA and performs up to 40% better than the best solution that has been published so far. The third implementation offers a constant time barrier in a separate network, leveraging commodity components, with a latency of only 2.5 microseconds. All components have their specialty and can be used to enhance the barrier performance significantly.

Die "Mitteilungen des URZ" informieren die Nutzer des Universitätsrechenzentrums der TU Chemnitz umfassend über neue Dienste und Projekte, vermitteln ggf. Hintergrundwissen und dienen der Berichterstattung.

Šiuo metu informacija yra sukaupta paskirstytuose šaltiniuose, kurie kaip saugojimo priemonę naudoja duomenų bazes. Šios bazės yra skirtingų tipų. Vartotojo tikslas yra naudoti keletą nepriklausomų informacijos šaltinių kaip vieną. Dėl savo nepriklausomumo nuo DBVS ir platformos tipo, XML tapo ypatingai naudingas atviroms susisiekiančioms sistemoms, kuomet duomenys apsikeičiami tarp paskirstytų duomenų šaltinių. Šiame darbe pateikiamas ontologijų, kaip dalykinės srities apibrėžimo informacijos paieškai, panaudojimas. Tai leidžia optimizuoti reikiamos informacijos paieškos procesą ir išvengti užklausos rezultatų pertekliškumo. / The main problem in heterogeneous database integration is data incompatibility in different databases. XML is perfect solution in data exchange between different databases as it is independent from OS, applications or hardware. To implement XML in data exchange XML must be created corresponding to the databases. This work propose use of ontologies for information retrieving from heterogenous data bases. Such method let optimize user query to avoid wasted information.

<p>Providing carrier grade characteristics for Internet Protocol (IP) communication applications is a significant problem for IP application providers in order to offer integrated services that span IP&nbsp / and telecommunication networks. This thesis addresses the provision of life-cycle management, which is only one carrier grade characteristic, for a SoftBridge application, which is an example of IP communication applications. A SoftBridge provides semi-synchronous multi-modal IP-based communication. The work related to IP-Telecommunication integrated services and the SoftBridge is analyzed with respect to life-cycle management in a literature review. It is suggested to use an Application Server in a Next Generation Network (NGN) to provide life-cyclemanagement functionality for IP-Telecommunication applications. In this thesis, the Application Server is represented by a JAIN Service Logic Execution Environment(JSLEE), in which&nbsp / a SoftBridge application can be deployed, activated, deactivated, uninstalled and upgraded online.Two methodologies are applied in this research: exploratory prototyping, which evolves the development of a SoftBridge application, and empirical comparison, which is concerned with the empirical evaluation of a SoftBridge application in terms of carriergrade capabilities. A SoftBridge application called SIMBA&nbsp / provides a Deaf Telephony service similar to aprevious Deaf Telephony SoftBridge, However, SIMBA&rsquo / s SoftBridge design and implementation are unique to this thesis. In order to test the life-cycle&nbsp / management ability of SIMBA, an empirical evaluation is carried out including the experiments oflife-cycle management and call-processing performance. The final experimental results of the evaluation show that a JSLEE is able to provide life-cycle management for SIMBA without causing a significant decrease in performance. In conclusion, the life-cycle management can be provided&nbsp / or a SoftBridge application by using an Application Server such as a JSLEE. Futhermore, the results indicate that&nbsp / approach of using Application Server (JSLEE) integration should be&nbsp / sufficiently general to provide life cycle management, and indeed other carrier grade capabilities, for other IP communication applications. This allows IP communication applications to be&nbsp / &nbsp / &nbsp / integrated into an NGN.</p>

This report covers the creation and implementation of a 3D audio application using FMOD Ex API. The report will also cover a walkthrough of the basic principles of 3D and surround audio, examples of other uses of 3D audio, a comparison between available technologies today, both software and hardware and finally the result of the implementation of the 3D sound environment software, both server and client. The application was created to explore the use of 3D audio in immersive environments. There was no application like this available when this project was conducted. An inductive approach along with a form of rapid application development and scenario creation was used to achieve the results presented in this report. The implementation resulted in a working client and server software which is able to create a 3D sound environment. Based on a user evaluation the software proved to be quite successful. With the help of the implementation the user, or operator, can now create a sound environment for another user, or a listener. The environment is created and designed by the operator using the client side of the implementation and later played through the server side which is connected to a 4.1 speaker system. The operator can steer and add sounds from the client to an active environment and the listener can experience the change in real time. This project was conducted as a bachelor thesis in computer science at Mälardalens University in Västerås, Sweden.

Network emulation has been widely used to aid in the development and evaluation of real-time applications. Many of today s applications and protocols need to be tested and evaluated in large scale network environments such as the Internet, which requires emulation tools that meet the requirements of scale, accuracy, timeliness. Due to physical resource constraints in network emulators, existing emulation tools fail to meet these requirements as they are either limited to small and static networks, use simplified network models, or fail to deliver timely emulation results. If more physical resources are devoted to network emulation by utilizing high performance computing facilities, the accuracy and scalability of network emulation can be greatly improved. However, for many users, high performance computing facilities may not be readily available in a local laboratory environment, and co-locating application code with a remote high performance computing facility may be cumbersome and inconvenient. This thesis proposes a network emulation approach called ROSENET (RemOte SErver-based Network EmulaTion) that utilizes a distributed server-based architecture in which local low-fidelity emulators provide real-time QoS predictions to distributed applications, coupled with a remote large scale high-fidelity simulator that continuously updates and calibrates the local low-fidelity emulators. A library-based modeling approach based on online simulation data collection is proposed and a system identification modeling technique is presented. Experimental results examining emulation end-to-end delay and loss show that ROSENET provides a promising approach to network emulation supporting accuracy and scale while meeting real-time constraints. Challenges faced in applying ROSENET to real world applications are addressed through two case studies including applying synthetic workload on DARPA s NMS network topology for large scale network simulation and a contemporary real-time distributed VoIP application Skype.

Thesis (Ph.D.)--University of Wollongong, 2005. / Typescript. Includes bibliographical references: leaf 88-95.

Based on the author's thesis (Ph.D.), 1993. / Includes bibliographical references ([239]-244) and index. Also issued online.

Humboldt-Univ., Diss.--Berlin, 2003.