@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} } @article{ToepferCorovicFetteetal.2015, author = {Toepfer, Martin and Corovic, Hamo and Fette, Georg and Kl{\"u}gl, Peter and St{\"o}rk, Stefan and Puppe, Frank}, title = {Fine-grained information extraction from German transthoracic echocardiography reports}, series = {BMC Medical Informatics and Decision Making}, volume = {15}, journal = {BMC Medical Informatics and Decision Making}, number = {91}, doi = {doi:10.1186/s12911-015-0215-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125509}, year = {2015}, abstract = {Background Information extraction techniques that get structured representations out of unstructured data make a large amount of clinically relevant information about patients accessible for semantic applications. These methods typically rely on standardized terminologies that guide this process. Many languages and clinical domains, however, lack appropriate resources and tools, as well as evaluations of their applications, especially if detailed conceptualizations of the domain are required. For instance, German transthoracic echocardiography reports have not been targeted sufficiently before, despite of their importance for clinical trials. This work therefore aimed at development and evaluation of an information extraction component with a fine-grained terminology that enables to recognize almost all relevant information stated in German transthoracic echocardiography reports at the University Hospital of W{\"u}rzburg. Methods A domain expert validated and iteratively refined an automatically inferred base terminology. The terminology was used by an ontology-driven information extraction system that outputs attribute value pairs. The final component has been mapped to the central elements of a standardized terminology, and it has been evaluated according to documents with different layouts. Results The final system achieved state-of-the-art precision (micro average.996) and recall (micro average.961) on 100 test documents that represent more than 90 \% of all reports. In particular, principal aspects as defined in a standardized external terminology were recognized with f 1=.989 (micro average) and f 1=.963 (macro average). As a result of keyword matching and restraint concept extraction, the system obtained high precision also on unstructured or exceptionally short documents, and documents with uncommon layout. Conclusions The developed terminology and the proposed information extraction system allow to extract fine-grained information from German semi-structured transthoracic echocardiography reports with very high precision and high recall on the majority of documents at the University Hospital of W{\"u}rzburg. Extracted results populate a clinical data warehouse which supports clinical research.}, language = {en} } @phdthesis{Hopfner2008, author = {Hopfner, Marbod}, title = {Source Code Analysis, Management, and Visualization for PROLOG}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-36300}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {This thesis deals with the management and analysis of source code, which is represented in XML. Using the elementary methods of the XML repository, the XML source code representation is accessed, changed, updated, and saved. We reason about the source code, refactor source code and we visualize dependency graphs for call analysis. The visualized dependencies between files, modules, or packages are used to structure the source code in order to get a system, which is easily to comprehend, to modify and to complete. Sophisticated methods have been developed to slice the source code in order to obtain a working package of a large system, containing only a specific functionality. The basic methods, on which the visualizations and analyses are built on can be changed like changing a plug-in. The visualization methods can be reused in order to handle arbitrary source code representations, e.g., JAML, PHPML, PROLOGML. Dependencies of other context can be visualized, too, e.g., ER diagrams, or website references. The tool SCAV supports source code visualization and analyzing methods.}, subject = {Refactoring}, language = {en} } @phdthesis{Binder2006, author = {Binder, Andreas}, title = {Die stochastische Wissenschaft und zwei Teilsysteme eines Web-basierten Informations- und Anwendungssystems zu ihrer Etablierung}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-26146}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2006}, abstract = {Das stochastische Denken, die Bernoullische Stochastik und dessen informationstechnologische Umsetzung, namens Stochastikon stellen die Grundlage f{\"u}r das Verst{\"a}ndnis und die erfolgreiche Nutzung einer stochastischen Wissenschaft dar. Im Rahmen dieser Arbeit erfolgt eine Kl{\"a}rung des Begriffs des stochastischen Denkens, eine anschauliche Darstellung der von Elart von Collani entwickelten Bernoullischen Stochastik und eine Beschreibung von Stochastikon. Dabei werden sowohl das Gesamtkonzept von Stochastikon, sowie die Ziele, Aufgaben und die Realisierung der beiden Teilsysteme namens Mentor und Encyclopedia vorgestellt. Das stochastische Denken erlaubt eine realit{\"a}tsnahe Sichtweise der Dinge, d.h. eine Sichtweise, die mit den menschlichen Beobachtungen und Erfahrungen im Einklang steht und somit die Unsicherheit {\"u}ber zuk{\"u}nftige Entwicklungen ber{\"u}cksichtigt. Der in diesem Kontext verwendete Begriff der Unsicherheit bezieht sich ausschließlich auf zuk{\"u}nftige Entwicklungen und {\"a}ußert sich in Variabilit{\"a}t. Quellen der Unsicherheit sind einerseits die menschliche Ignoranz und andererseits der Zufall. Unter Ignoranz wird hierbei die Unwissenheit des Menschen {\"u}ber die unbekannten, aber feststehenden Fakten verstanden, die die Anfangsbedingungen der zuk{\"u}nftigen Entwicklung repr{\"a}sentieren. Die Bernoullische Stochastik liefert ein Regelwerk und erm{\"o}glicht die Entwicklung eines quantitativen Modells zur Beschreibung der Unsicherheit und expliziter Einbeziehung der beiden Quellen Ignoranz und Zufall. Das Modell tr{\"a}gt den Namen Bernoulli-Raum und bildet die Grundlage f{\"u}r die Herleitung quantitativer Verfahren, um zuverl{\"a}ssige und genaue Aussagen sowohl {\"u}ber die nicht-existente zuf{\"a}llige Zukunft (Vorhersageverfahren), als auch {\"u}ber die unbekannte feststehende Vergangenheit (Messverfahren). Das Softwaresystem Stochastikon implementiert die Bernoullische Stochastik in Form einer Reihe autarker, miteinander kommunizierender Teilsysteme. Ziel des Teilsystems Encyclopedia ist die Bereitstellung und Bewertung stochastischen Wissens. Das Teilsystem Mentor dient der Unterst{\"u}tzung des Anwenders bei der Probleml{\"o}sungsfindung durch Identifikation eines richtigen Modells bzw. eines korrekten Bernoulli-Raums. Der L{\"o}sungsfindungsprozess selber enth{\"a}lt keinerlei Unsicherheit. Die ganze Unsicherheit steckt in der L{\"o}sung, d.h. im Bernoulli-Raum, der explizit die vorhandene Unwissenheit (Ignoranz) und den vorliegenden Zufall abdeckend enth{\"a}lt.}, subject = {Stochastik}, language = {de} } @phdthesis{Binzenhoefer2007, author = {Binzenh{\"o}fer, Andreas}, title = {Performance Analysis of Structured Overlay Networks}, doi = {10.25972/OPUS-2250}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-26291}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2007}, abstract = {Overlay networks establish logical connections between users on top of the physical network. While randomly connected overlay networks provide only a best effort service, a new generation of structured overlay systems based on Distributed Hash Tables (DHTs) was proposed by the research community. However, there is still a lack of understanding the performance of such DHTs. Additionally, those architectures are highly distributed and therefore appear as a black box to the operator. Yet an operator does not want to lose control over his system and needs to be able to continuously observe and examine its current state at runtime. This work addresses both problems and shows how the solutions can be combined into a more self-organizing overlay concept. At first, we evaluate the performance of structured overlay networks under different aspects and thereby illuminate in how far such architectures are able to support carrier-grade applications. Secondly, to enable operators to monitor and understand their deployed system in more detail, we introduce both active as well as passive methods to gather information about the current state of the overlay network.}, subject = {Overlay-Netz}, language = {en} } @phdthesis{Pries2010, author = {Pries, Jan Rastin}, title = {Performance Optimization of Wireless Infrastructure and Mesh Networks}, doi = {10.25972/OPUS-3723}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-46097}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2010}, abstract = {Future broadband wireless networks should be able to support not only best effort traffic but also real-time traffic with strict Quality of Service (QoS) constraints. In addition, their available resources are scare and limit the number of users. To facilitate QoS guarantees and increase the maximum number of concurrent users, wireless networks require careful planning and optimization. In this monograph, we studied three aspects of performance optimization in wireless networks: resource optimization in WLAN infrastructure networks, quality of experience control in wireless mesh networks, and planning and optimization of wireless mesh networks. An adaptive resource management system is required to effectively utilize the limited resources on the air interface and to guarantee QoS for real-time applications. Thereby, both WLAN infrastructure and WLAN mesh networks have to be considered. An a-priori setting of the access parameters is not meaningful due to the contention-based medium access and the high dynamics of the system. Thus, a management system is required which dynamically adjusts the channel access parameters based on the network load. While this is sufficient for wireless infrastructure networks, interferences on neighboring paths and self-interferences have to be considered for wireless mesh networks. In addition, a careful channel allocation and route assignment is needed. Due to the large parameter space, standard optimization techniques fail for optimizing large wireless mesh networks. In this monograph, we reveal that biology-inspired optimization techniques, namely genetic algorithms, are well-suitable for the planning and optimization of wireless mesh networks. Although genetic algorithms generally do not always find the optimal solution, we show that with a good parameter set for the genetic algorithm, the overall throughput of the wireless mesh network can be significantly improved while still sharing the resources fairly among the users.}, subject = {IEEE 802.11}, language = {en} } @inproceedings{EppleeLangbehn2021, author = {Eppl{\´e}e, Rafael and Langbehn, Eike}, title = {Overlapping Architecture: Implementation of Impossible Spaces in Virtual Reality Games}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246045}, pages = {37-46}, year = {2021}, abstract = {Natural walking in virtual reality games is constrained by the physical boundaries defined by the size of the player's tracking space. Impossible spaces, a redirected walking technique, enlarge the virtual environment by creating overlapping architecture and letting multiple locations occupy the same physical space. Within certain thresholds, this is subtle to the player. In this paper, we present our approach to implement such impossible spaces and describe how we handled challenges like objects with simulated physics or precomputed global illumination.}, language = {en} } @phdthesis{Busch2016, author = {Busch, Stephan}, title = {Robust, Flexible and Efficient Design for Miniature Satellite Systems}, isbn = {978-3-945459-10-2}, doi = {10.25972/OPUS-13652}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-136523}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2016}, abstract = {Small satellites contribute significantly in the rapidly evolving innovation in space engineering, in particular in distributed space systems for global Earth observation and communication services. Significant mass reduction by miniaturization, increased utilization of commercial high-tech components, and in particular standardization are the key drivers for modern miniature space technology. This thesis addresses key fields in research and development on miniature satellite technology regarding efficiency, flexibility, and robustness. Here, these challenges are addressed by the University of Wuerzburg's advanced pico-satellite bus, realizing a generic modular satellite architecture and standardized interfaces for all subsystems. The modular platform ensures reusability, scalability, and increased testability due to its flexible subsystem interface which allows efficient and compact integration of the entire satellite in a plug-and-play manner. Beside systematic design for testability, a high degree of operational robustness is achieved by the consequent implementation of redundancy of crucial subsystems. This is combined with efficient fault detection, isolation and recovery mechanisms. Thus, the UWE-3 platform, and in particular the on-board data handling system and the electrical power system, offers one of the most efficient pico-satellite architectures launched in recent years and provides a solid basis for future extensions. The in-orbit performance results of the pico-satellite UWE-3 are presented and summarize successful operations since its launch in 2013. Several software extensions and adaptations have been uploaded to UWE-3 increasing its capabilities. Thus, a very flexible platform for in-orbit software experiments and for evaluations of innovative concepts was provided and tested.}, subject = {Kleinsatellit}, language = {en} } @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} } @article{KuhnGrippFliederetal.2015, author = {Kuhn, Joachim and Gripp, Tatjana and Flieder, Tobias and Dittrich, Marcus and Hendig, Doris and Busse, Jessica and Knabbe, Cornelius and Birschmann, Ingvild}, title = {UPLC-MRM Mass Spectrometry Method for Measurement of the Coagulation Inhibitors Dabigatran and Rivaroxaban in Human Plasma and Its Comparison with Functional Assays}, series = {PLOS ONE}, volume = {10}, journal = {PLOS ONE}, number = {12}, doi = {10.1371/journal.pone.0145478}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-136023}, pages = {e0145478}, year = {2015}, abstract = {Introduction The fast, precise, and accurate measurement of the new generation of oral anticoagulants such as dabigatran and rivaroxaban in patients' plasma my provide important information in different clinical circumstances such as in the case of suspicion of overdose, when patients switch from existing oral anticoagulant, in patients with hepatic or renal impairment, by concomitant use of interaction drugs, or to assess anticoagulant concentration in patients' blood before major surgery. Methods Here, we describe a quick and precise method to measure the coagulation inhibitors dabigatran and rivaroxaban using ultra-performance liquid chromatography electrospray ionization-tandem mass spectrometry in multiple reactions monitoring (MRM) mode (UPLC-MRM MS). Internal standards (ISs) were added to the sample and after protein precipitation; the sample was separated on a reverse phase column. After ionization of the analytes the ions were detected using electrospray ionization-tandem mass spectrometry. Run time was 2.5 minutes per injection. Ion suppression was characterized by means of post-column infusion. Results The calibration curves of dabigatran and rivaroxaban were linear over the working range between 0.8 and 800 mu g/L (r > 0.99). Limits of detection (LOD) in the plasma matrix were 0.21 mu g/L for dabigatran and 0.34 mu g/L for rivaroxaban, and lower limits of quantification (LLOQ) in the plasma matrix were 0.46 mu g/L for dabigatran and 0.54 mu g/L for rivaroxaban. The intraassay coefficients of variation (CVs) for dabigatran and rivaroxaban were < 4\% and 6\%; respectively, the interassay CVs were < 6\% for dabigatran and < 9\% for rivaroxaban. Inaccuracy was < 5\% for both substances. The mean recovery was 104.5\% (range 83.8-113.0\%) for dabigatran and 87.0\%(range 73.6-105.4\%) for rivaroxaban. No significant ion suppressions were detected at the elution times of dabigatran or rivaroxaban. Both coagulation inhibitors were stable in citrate plasma at -20 degrees C, 4 degrees C and even at RT for at least one week. A method comparison between our UPLC-MRM MS method, the commercially available automated Direct Thrombin Inhibitor assay (DTI assay) for dabigatran measurement from CoaChrom Diagnostica, as well as the automated anti-Xa assay for rivaroxaban measurement from Chromogenix both performed by ACL-TOP showed a high degree of correlation. However, UPLC-MRM MS measurement of dabigatran and rivaroxaban has a much better selectivity than classical functional assays measuring activities of various coagulation factors which are susceptible to interference by other coagulant drugs. Conclusions Overall, we developed and validated a sensitive and specific UPLC-MRM MS assay for the quick and specific measurement of dabigatran and rivaroxaban in human plasma.}, language = {en} }