TY - THES A1 - Zinner, Thomas T1 - Performance Modeling of QoE-Aware Multipath Video Transmission in the Future Internet T1 - Leistungsmodellierung einer Mehrpfad Video Übertragung im zukünftigen Internet unter Berücksichtigung der QoE N2 - Internet applications are becoming more and more flexible to support diverge user demands and network conditions. This is reflected by technical concepts, which provide new adaptation mechanisms to allow fine grained adjustment of the application quality and the corresponding bandwidth requirements. For the case of video streaming, the scalable video codec H.264/SVC allows the flexible adaptation of frame rate, video resolution and image quality with respect to the available network resources. In order to guarantee a good user-perceived quality (Quality of Experience, QoE) it is necessary to adjust and optimize the video quality accurately. But not only have the applications of the current Internet changed. Within network and transport, new technologies evolved during the last years providing a more flexible and efficient usage of data transport and network resources. One of the most promising technologies is Network Virtualization (NV) which is seen as an enabler to overcome the ossification of the Internet stack. It provides means to simultaneously operate multiple logical networks which allow for example application-specific addressing, naming and routing, or their individual resource management. New transport mechanisms like multipath transmission on the network and transport layer aim at an efficient usage of available transport resources. However, the simultaneous transmission of data via heterogeneous transport paths and communication technologies inevitably introduces packet reordering. Additional mechanisms and buffers are required to restore the correct packet order and thus to prevent a disturbance of the data transport. A proper buffer dimensioning as well as the classification of the impact of varying path characteristics like bandwidth and delay require appropriate evaluation methods. Additionally, for a path selection mechanism real time evaluation mechanisms are needed. A better application-network interaction and the corresponding exchange of information enable an efficient adaptation of the application to the network conditions and vice versa. This PhD thesis analyzes a video streaming architecture utilizing multipath transmission and scalable video coding and develops the following optimization possibilities and results: Analysis and dimensioning methods for multipath transmission, quantification of the adaptation possibilities to the current network conditions with respect to the QoE for H.264/SVC, and evaluation and optimization of a future video streaming architecture, which allows a better interaction of application and network. N2 - Die Applikationen im Internet passen sich immer besser an unterschiedliche Anforderungen der Nutzer und variierende Netzwerkbedingungen an. Neue Mechanismen ermöglichen die zielgerichtete Anpassung der Anwendungsqualität und damit der benötigten Bandbreite. Im Falle von Videostreaming ermöglicht der skalierbare Videocodec H.264/SVC, die flexible Veränderung der Bildwiederholungsrate, der Auflösung des Videos und der Bildqualität an die vorhandenen Ressourcen im Netzwerk. Um eine gute vom Nutzer erfahrene Dienstgüte (Quality of Experience, QoE) zu garantieren, muss die Videoqualität richtig angepasst und optimiert werden. Aber nicht nur die Anwendungen des heutigen Internets haben sich verändert. Gerade in den letzten Jahren entstanden neue Netzwerk- und Transporttechnologien, welche eine flexiblere und effizientere Nutzung der Kommunikationsnetze erlauben. Eine dieser Techniken ist die Virtualisierung von Netzwerken. Sie erlaubt es auf einem gemeinsamen physikalischen Netz verschiedene logische Netze zu betreiben, die zum Beispiel Anwendungs-abhängige Adressierung unterstützen, eigene Namensgebung erlauben oder ein individuelles Ressourcen Management ermöglichen. Neuartige Transportmechanismen wie Mehrpfadübertragung auf Netzwerk- und Transportebene des ISO/OSI Stacks streben eine effiziente Ausnutzung der zur Verfügung stehenden Übertragungsmöglichkeiten an. Doch die simultane Übertragung von Daten über heterogene Kommunikationspfade und –technologien führt unausweichlich zu einer Veränderung der Reihenfolge, in der die Pakete ankommen. Es werden zusätzliche Mechanismen und Puffer benötigt, um die ursprüngliche Paketreihenfolge wieder herzustellen und so einen störenden Einfluss auf den Datentransport zu verhindern. Die richtige Dimensionierung dieser Puffer sowie die Klassifizierung des Einflusses von variierenden Pfadparametern wie Bandbreite und Verzögerungen setzen passende Evaluierungsmethoden voraus. Darüber hinaus werden für die Auswahl von geeigneten Pfaden aus einer Menge vorhandener Pfade echtzeitfähige Bewertungsmechanismen benötigt. Eine bessere Interaktion zwischen Applikationen und Netzwerk und der damit verbundene Informationsaustausch ermöglicht die effiziente Anpassung der Applikationsqualität an das Netzwerk und umgekehrt. Diese Doktorarbeit analysiert eine auf Mehrpfadübertragung und skalierbarer Videokodierung basierende Videostreaming Architektur und erarbeitet die folgenden Optimierungsmöglichkeiten und Auswertungen: Analyse- und Dimensionierungsmethoden für Mehrpfadübertragung, Quantifizierung der Anpassungsmöglichkeiten von SVC an das Netzwerk unter Berücksichtigung der QoE und Evaluierung und Optimierung einer zukünftigen Videostreaming Architektur, welche eine stärkere Interaktion zwischen Applikation und Netzwerk ermöglicht. T3 - Würzburger Beiträge zur Leistungsbewertung Verteilter Systeme - 03/12 KW - Videoübertragung KW - H.264 SVC KW - Modellierung KW - Quality-of-Experience KW - Mehrpfadübertragung KW - Multipath Transmission KW - Video Streaming KW - H.264/SVC KW - QoE KW - Performance Modeling Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-72324 ER - TY - JOUR A1 - Zirkel, J. A1 - Cecil, A. A1 - Schäfer, F. A1 - Rahlfs, S. A1 - Ouedraogo, A. A1 - Xiao, K. A1 - Sawadogo, S. A1 - Coulibaly, B. A1 - Becker, K. A1 - Dandekar, T. T1 - Analyzing Thiol-Dependent Redox Networks in the Presence of Methylene Blue and Other Antimalarial Agents with RT-PCR-Supported in silico Modeling JF - Bioinformatics and Biology Insights N2 - BACKGROUND: In the face of growing resistance in malaria parasites to drugs, pharmacological combination therapies are important. There is accumulating evidence that methylene blue (MB) is an effective drug against malaria. Here we explore the biological effects of both MB alone and in combination therapy using modeling and experimental data. RESULTS: We built a model of the central metabolic pathways in P. falciparum. Metabolic flux modes and their changes under MB were calculated by integrating experimental data (RT-PCR data on mRNAs for redox enzymes) as constraints and results from the YANA software package for metabolic pathway calculations. Several different lines of MB attack on Plasmodium redox defense were identified by analysis of the network effects. Next, chloroquine resistance based on pfmdr/and pfcrt transporters, as well as pyrimethamine/sulfadoxine resistance (by mutations in DHF/DHPS), were modeled in silico. Further modeling shows that MB has a favorable synergism on antimalarial network effects with these commonly used antimalarial drugs. CONCLUSIONS: Theoretical and experimental results support that methylene blue should, because of its resistance-breaking potential, be further tested as a key component in drug combination therapy efforts in holoendemic areas. KW - methylene blue KW - malaria KW - elementary mode analysis KW - drug KW - resistance KW - combination therapy KW - pathway KW - metabolic flux Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123751 N1 - This is an open access article. Unrestricted non-commercial use is permitted provided the original work is properly cited. VL - 6 ER - TY - CHAP ED - Kolla, Reiner T1 - 9. Fachgespräch Sensornetze der GI/ITG Fachgruppe Kommunikation und Verteilte Systeme N2 - Jährliches Fachgespräch zu Sensornetzen der GI/ITG Fachgruppe Kommunikation und Verteilte Systeme, 16. - 17. September 2010, Universität Würzburg KW - Drahtloses Sensorsystem KW - Fachgespräch KW - Aufsatzsammlung KW - sensor network KW - wireless network Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-51106 ER - TY - GEN T1 - Jahresbericht 2014 T1 - Annual Report 2014 N2 - Jahresbericht 2014 des Rechenzentrums der Universität Würzburg N2 - Annual Report 2014 of the Computer Center, University of Wuerzburg T3 - Jahresbericht des Rechenzentrums der Universität Würzburg - 2014 KW - Rechenzentrum Universität Würzburg KW - annual report KW - Computer Center University of Wuerzburg KW - Jahresbericht Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124432 UR - https://www.rz.uni-wuerzburg.de/infos/publikationen/ ER - TY - GEN T1 - Jahresbericht 2015 T1 - Annual Report 2015 N2 - Jahresbericht 2015 des Rechenzentrums der Universität Würzburg N2 - Annual Report 2015 of the Computer Center, University of Wuerzburg T3 - Jahresbericht des Rechenzentrums der Universität Würzburg - 2015 KW - Julius-Maximilians-Universität Würzburg. Rechenzentrum KW - annual report KW - Computer Center University of Wuerzburg KW - Jahresbericht KW - RZUW Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-136599 UR - https://www.rz.uni-wuerzburg.de/wir/publikationen/ ER - TY - RPRT ED - Hoßfeld, Tobias ED - Wunderer, Stefan T1 - White Paper on Crowdsourced Network and QoE Measurements – Definitions, Use Cases and Challenges N2 - The goal of the white paper at hand is as follows. The definitions of the terms build a framework for discussions around the hype topic ‘crowdsourcing’. This serves as a basis for differentiation and a consistent view from different perspectives on crowdsourced network measurements, with the goal to provide a commonly accepted definition in the community. The focus is on the context of mobile and fixed network operators, but also on measurements of different layers (network, application, user layer). In addition, the white paper shows the value of crowdsourcing for selected use cases, e.g., to improve QoE or regulatory issues. Finally, the major challenges and issues for researchers and practitioners are highlighted. This white paper is the outcome of the Würzburg seminar on “Crowdsourced Network and QoE Measurements” which took place from 25-26 September 2019 in Würzburg, Germany. International experts were invited from industry and academia. They are well known in their communities, having different backgrounds in crowdsourcing, mobile networks, network measurements, network performance, Quality of Service (QoS), and Quality of Experience (QoE). The discussions in the seminar focused on how crowdsourcing will support vendors, operators, and regulators to determine the Quality of Experience in new 5G networks that enable various new applications and network architectures. As a result of the discussions, the need for a white paper manifested, with the goal of providing a scientific discussion of the terms “crowdsourced network measurements” and “crowdsourced QoE measurements”, describing relevant use cases for such crowdsourced data, and its underlying challenges. During the seminar, those main topics were identified, intensively discussed in break-out groups, and brought back into the plenum several times. The outcome of the seminar is this white paper at hand which is – to our knowledge – the first one covering the topic of crowdsourced network and QoE measurements. KW - Crowdsourcing KW - Network Measurements KW - Quality of Service (QoS) KW - Quality of Experience (QoE) KW - crowdsourced network measurements KW - crowdsourced QoE measurements Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202327 ER - TY - CHAP ED - von Mammen, Sebastian ED - Klemke, Roland ED - Lorber, Martin T1 - Proceedings of the 1st Games Technology Summit BT - part of Clash of Realites 11th International Conference on the Technology and Theory of Digital Games N2 - As part of the Clash of Realities International Conference on the Technology and Theory of Digital Games, the Game Technology Summit is a premium venue to bring together experts from academia and industry to disseminate state-of-the-art research on trending technology topics in digital games. In this first iteration of the Game Technology Summit, we specifically paid attention on how the successes in AI in Natural User Interfaces have been impacting the games industry (industry track) and which scientific, state-of-the-art ideas and approaches are currently pursued (scientific track). KW - Veranstaltung KW - Künstliche Intelligenz KW - Mensch-Maschine-Kommunikation KW - Computerspiel KW - natural user interfaces KW - artificial intelligence Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-245776 SN - 978-3-945459-36-2 ER - TY - GEN T1 - Jahresbericht 2016 des Rechenzentrums der Universität Würzburg T1 - Annual Report 2016 of the Computer Center, University of Wuerzburg N2 - Das Dokument umfasst eine jährliche Zusammenfassung der Aktivitäten des Rechenzentrums als zentraler IT-Dienstleister der Universität Würzburg T3 - Jahresbericht des Rechenzentrums der Universität Würzburg - 2016 KW - Jahresbericht KW - Julius-Maximilians-Universität Würzburg KW - Rechenzentrum KW - annual report KW - Computer Center University of Wuerzburg KW - RZUW Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-153558 UR - https://www.rz.uni-wuerzburg.de/wir/publikationen/ ET - 1. Auflage ER -