@phdthesis{Zinner2012, author = {Zinner, Thomas}, title = {Performance Modeling of QoE-Aware Multipath Video Transmission in the Future Internet}, doi = {10.25972/OPUS-6106}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72324}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {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.}, subject = {Video{\"u}bertragung}, language = {en} } @article{ZirkelCecilSchaeferetal.2012, author = {Zirkel, J. and Cecil, A. and Sch{\"a}fer, F. and Rahlfs, S. and Ouedraogo, A. and Xiao, K. and Sawadogo, S. and Coulibaly, B. and Becker, K. and Dandekar, T.}, title = {Analyzing Thiol-Dependent Redox Networks in the Presence of Methylene Blue and Other Antimalarial Agents with RT-PCR-Supported in silico Modeling}, series = {Bioinformatics and Biology Insights}, volume = {6}, journal = {Bioinformatics and Biology Insights}, doi = {10.4137/BBI.S10193}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123751}, pages = {287-302}, year = {2012}, abstract = {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.}, language = {en} } @inproceedings{OPUS4-4233, title = {9. Fachgespr{\"a}ch Sensornetze der GI/ITG Fachgruppe Kommunikation und Verteilte Systeme}, editor = {Kolla, Reiner}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-51106}, year = {2010}, abstract = {J{\"a}hrliches Fachgespr{\"a}ch zu Sensornetzen der GI/ITG Fachgruppe Kommunikation und Verteilte Systeme, 16. - 17. September 2010, Universit{\"a}t W{\"u}rzburg}, subject = {Drahtloses Sensorsystem}, language = {mul} } @misc{OPUS4-12443, title = {Jahresbericht 2014}, organization = {Rechenzentrum (Universit{\"a}t W{\"u}rzburg)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124432}, pages = {90}, year = {2016}, abstract = {Jahresbericht 2014 des Rechenzentrums der Universit{\"a}t W{\"u}rzburg}, subject = {Rechenzentrum Universit{\"a}t W{\"u}rzburg}, language = {de} } @misc{OPUS4-13659, title = {Jahresbericht 2015}, organization = {Rechenzentrum (Universit{\"a}t W{\"u}rzburg)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-136599}, pages = {88}, year = {2016}, abstract = {Jahresbericht 2015 des Rechenzentrums der Universit{\"a}t W{\"u}rzburg}, subject = {Julius-Maximilians-Universit{\"a}t W{\"u}rzburg. Rechenzentrum}, language = {de} } @techreport{OPUS4-20232, type = {Working Paper}, title = {White Paper on Crowdsourced Network and QoE Measurements - Definitions, Use Cases and Challenges}, editor = {Hoßfeld, Tobias and Wunderer, Stefan}, doi = {10.25972/OPUS-20232}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202327}, pages = {24}, year = {2020}, abstract = {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 W{\"u}rzburg seminar on "Crowdsourced Network and QoE Measurements" which took place from 25-26 September 2019 in W{\"u}rzburg, 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.}, subject = {Crowdsourcing}, language = {en} } @inproceedings{OPUS4-24577, title = {Proceedings of the 1st Games Technology Summit}, editor = {von Mammen, Sebastian and Klemke, Roland and Lorber, Martin}, isbn = {978-3-945459-36-2}, doi = {10.25972/OPUS-24577}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245776}, pages = {vi, 46}, year = {2021}, abstract = {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).}, subject = {Veranstaltung}, language = {en} } @misc{OPUS4-15355, title = {Jahresbericht 2016 des Rechenzentrums der Universit{\"a}t W{\"u}rzburg}, edition = {1. Auflage}, organization = {Rechenzentrum (Universit{\"a}t W{\"u}rzburg)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-153558}, pages = {72}, year = {2017}, abstract = {Das Dokument umfasst eine j{\"a}hrliche Zusammenfassung der Aktivit{\"a}ten des Rechenzentrums als zentraler IT-Dienstleister der Universit{\"a}t W{\"u}rzburg}, subject = {Jahresbericht}, language = {de} }