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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Towards next-generation sequencing-based identification of norovirus recognition elements and microfluidic array using phage display technology / Phage Display als Tool zur Next Generation Sequencing-basierten Identifizierung von Norovirus-Erkennungselementen und zur Entwicklung eines mikrofluidischen Arrays

Pahlke, Claudia 28 November 2017 (has links) (PDF)
Noroviruses are the major cause of acute viral gastroenteritis worldwide. Thus, rapid and reliable pathogen detection and control are crucial to avoid epidemic outbreaks. Peptides which bind to these viruses with high specificity and affinity could serve as small and stable recognition elements in biosensing applications for a point-of-care diagnostic of noroviruses. They can be identified by screening large phage display libraries using the biopanning technique. In the present study, this method was applied to identify norovirus-binding peptide motifs. For this purpose, a biopanning based on column chromatography was established, and three rounds of selections were performed. After the second round, the cosmix-plexing recombination technique was implemented to enhance the chance of obtaining peptides with very high affinity. Biopanning data evaluation was based on next-generation sequencing (NGS), to show that this innovative method can enable a detailed analysis of the complete sequence spectrum obtained during and after biopanning. Highly enriched motifs could be characterized by their large proportion of the amino acids W, K, R, N, and F. Neighbourhood analysis was exemplarily performed for selected motifs, showing that the motifs FAT, RWN, and KWF possessed the fingerprints with the largest differences relative to the original library. This thesis thus presents next-generation sequencing-based analysis tools, which could now be transferred to any other biopanning project. The identified peptide motifs represent promising candidates for a future examination of their norovirus-specific binding. A new option for testing such phage-target interactions in the context of biopanning selections was studied in the second part of the thesis. For this purpose, a phage-based microarray was developed as a miniaturized binding assay. As a prerequisite, the different immobilization behaviour of phages on positively and negatively charged surfaces was studied, and a non-contact printing technique for bacteriophages was developed. Subsequently, the interaction of phages and antibodies directed against phage coat proteins was characterized in enzyme-linked immunosorbent assays, and the protocol was successfully transferred to the non-contact printed phage spots. At the proof-of-concept level, the phage array could finally be integrated into a microfluidic setup, showing a higher signal-to-background ratio relative to the static phage array. These results point the way towards a microfluidic phage array, allowing online monitoring, automation, and parallelisation of the phage array analysis. / Noroviren gelten als Hauptursache akuter viraler Magen-Darm-Erkrankungen. Nur eine zeitnahe und verlässliche Detektion und Kontrolle dieser Pathogene kann epidemische Ausbrüche vermeiden. Um dies zu ermöglichen, könnten Peptide, die an diese Viren mit hoher Spezifität und Affinität binden, als kleine und stabile Erkennungselemente in biosensorischen Anwendungen eingesetzt werden. Solche Peptide können mithilfe der Biopanning-Technik identifiziert werden, die auf dem Screening großer Phagen-Display-Bibliotheken beruht. In der vorliegenden Arbeit wurde diese Methode genutzt, um Norovirus-bindende Peptidmotive zu identifizieren. Dazu wurde ein auf Säulenchromatographie basierendes Biopanning entwickelt und drei Selektionsrunden durchgeführt. Die Cosmix-Plexing-Rekombinationstechnik wurde nach der zweiten Runde eingesetzt, um die Wahrscheinlichkeit der Gewinnung hochaffiner Binder zu erhöhen. Die Auswertung der Biopanningdaten erfolgte mittels Hochdurchsatzsequenzierung (Next-Generation Sequencing). Es konnte gezeigt werden, dass diese innovative Methode die detailierte Analyse des kompletten Sequenzspektrums während und nach dem Biopanning ermöglicht. Stark angereicherte Motive konnten durch ihren hohen Anteil an den Aminosäuren W, K, R, N und F charakterisiert werden. Eine Nachbarschaftsanalyse wurde exemplarisch für ausgewählte Motive durchgeführt. Dabei wurden die stärksten Unterschiede im Fingerprint im Vergleich zur Ausgangsbibliothek bei den Motiven FAT, RWN und KWF gefunden. Diese Dissertation stellt damit auf Next-Generation Sequencing basierende Analysetechniken vor, die für weitere Biopanningprojekte übernommen werden können. Die identifizierten Peptidmotive könnten als vielversprechende Kandidaten zukünftig auf ihre Norovirus-spezifische Bindung hin getestet werden. Eine neue Möglichkeit, solche Phagen-Analyt-Interaktionen zu untersuchen, wurde im zweiten Teil der Dissertation untersucht. Dafür wurde als miniaturisierter Bindungsassay ein Phagen-basiertes Mikroarray entwickelt. Als Voraussetzung wurde zunächst das unterschiedliche Immobilisierungsverhalten von Bakteriophagen auf positiv und negativ geladenen Oberflächen untersucht und eine kontaktfreie Drucktechnik für Bakteriophagen etabliert. Anschließend wurde die Interaktion von Phagen und gegen sie gerichteten Antikörpern in Enzym-gekoppelten Immunadsorptionstests charakterisiert und das Protokoll erfolgreich auf die kontaktfrei gedruckten Phagenspots übertragen. Schließlich wurde erstmals die grundsätzliche Möglichkeit gezeigt, das Array in ein mikrofluidisches Setup zu integrieren, was zu einem höheren Signal-zu-Hintergrund-Verhältnis im Vergleich zum statischen Array führte. Diese Ergebnisse zeigen damit den Weg zu einem mikrofluidischen Phagen-Array auf, das sowohl die Möglichkeit des Online-Monitorings als auch der Automatisierung und Parallelisierung der Phagen-Array-Analyse bietet.
102

Nachtrag zur Veranstaltung „Keine Sackgasse: Schnelles Internet und Straßenausbau im kommunalen Fokus“

Kilian, Maike 13 June 2019 (has links)
Die Verfügbarkeit von Breitbandnetzen wird für die Sicherung und Weiterentwicklung des Wirtschafts-, Technologie- und Tourismusstandortes Sachsen immer wichtiger. Eine gute Nachricht gleich zu Beginn: Das Land Sachsen stellt seit Ende letzten Jahres Fördermittel für den Aufbau von Breitbandnetzen auch für die zukunftsfähigen Next-Generation-Access-Netze (NGA) zur Verfügung. Zuwendungsempfänger sind neben Gemeinden, Landkreisen, Verwaltungsgemeinschaften und Gemeindeverbände auch Eigenbetriebe und Zweckverbände. Das ließ viele Zuhörer auf der Informationsveranstaltung „Breitband und Straßen als kommunale Herausforderung“ am 26. März 2015 in Leipzig aufhorchen.
103

A critical appraisal of the European Commission´s policy towards regulating next generation communications networks

Briglauer, Wolfgang, Gugler, Klaus January 2012 (has links) (PDF)
Fiber-deployment of telecommunications networks is currently a great challenge for sector-specific regulators, national governments, as well as for investing operators. One of the most controversial regulatory issues in Europe (and elsewhere) is whether the emerging next generation access (NGA) infrastructure should be subjected to cost-based access regulation or whether at least a temporary removal of ex ante obligations ("regulatory holidays") should be granted. In answering this question we examine the current and foreseeable EU regulatory framework and show that it does not provide positive incentives for NGA deployment and increasing penetration rates. On the basis of an international comparison with the most recent data on NGA deployment and penetration, it appears, in turn, that deregulatory and/or state aid driven approaches targeted at the demand (subscribers) and supply side (coverage) are more promising. (author's abstract) / Series: Working Papers / Research Institute for Regulatory Economics
104

Efficient contracts for government intervention in promoting next generation communications networks

Briglauer, Wolfgang, Holzleitner, Christian 07 1900 (has links) (PDF)
Although the future socio-economic benefits of a new fibre-based ("next generation access", NGA) telecommunications infrastructure seem to be uncontroversial, most countries have to date only undertaken NGA investments on a small scale. Accordingly, a universal NGA coverage appears to be a rather unrealistic objective without government intervention. Indeed, many governments have already initiated diverse subsidy programs in order to stimulate NGA infrastructure deployment. We contend, however, that the current contract practice of fixing ex ante targets for network expansion is inefficient given the uncertainty about future returns on NGA infrastructure-based services and the public authorities' incomplete information about the capital costs of the network provider. This paper puts forward to delegate the choice of the network expansion to the NGA provider. Simple linear profit-sharing contracts can be designed to control the NGA provider's incentives and to put in balance the public objectives of network expansion and limitation of public expenditure. (author's abstract) / Series: Working Papers / Research Institute for Regulatory Economics
105

Formalization of a converged internet and telecommunications service environment

Blum, Niklas January 2010 (has links)
The programmable network envisioned in the 1990s within standardization and research for the Intelligent Network is currently coming into reality using IPbased Next Generation Networks (NGN) and applying Service-Oriented Architecture (SOA) principles for service creation, execution, and hosting. SOA is the foundation for both next-generation telecommunications and middleware architectures, which are rapidly converging on top of commodity transport services. Services such as triple/quadruple play, multimedia messaging, and presence are enabled by the emerging service-oriented IPMultimedia Subsystem (IMS), and allow telecommunications service providers to maintain, if not improve, their position in the marketplace. SOA becomes the de facto standard in next-generation middleware systems as the system model of choice to interconnect service consumers and providers within and between enterprises. We leverage previous research activities in overlay networking technologies along with recent advances in network abstraction, service exposure, and service creation to develop a paradigm for a service environment providing converged Internet and Telecommunications services that we call Service Broker. Such a Service Broker provides mechanisms to combine and mediate between different service paradigms from the two domains Internet/WWW and telecommunications. Furthermore, it enables the composition of services across these domains and is capable of defining and applying temporal constraints during creation and execution time. By adding network-awareness into the service fabric, such a Service Broker may also act as a next generation network-to-service element allowing the composition of crossdomain and cross-layer network and service resources. The contribution of this research is threefold: first, we analyze and classify principles and technologies from Information Technologies (IT) and telecommunications to identify and discuss issues allowing cross-domain composition in a converging service layer. Second, we discuss service composition methods allowing the creation of converged services on an abstract level; in particular, we present a formalized method for model-checking of such compositions. Finally, we propose a Service Broker architecture converging Internet and Telecom services. This environment enables cross-domain feature interaction in services through formalized obligation policies acting as constraints during service discovery, creation, and execution time. / Das programmierbare Netz, das Ende des 20. Jahrhunderts in der Standardisierung und Forschung für das Intelligente Netz entworfen wurde, wird nun Realität in einem auf das Internet Protokoll basierendem Netz der nächsten Generation (Next Generation Network). Hierfür kommen Prinzipien aus der Informationstechnologie, insbesondere aus dem Bereich dienstorientierte Architekturen (Service-Oriented Architecture / SOA) für die Diensterstellung, -ausführung und -betrieb zum Tragen. SOA bietet hierbei die theoretische Grundlage für Telekommunikationsnetze, vor allem jedoch für die dazugehörigen Dienstplattformen. Diese erlauben dem Telekommunikationsbetreiber seine Position in einem offenen Marktplatz der Dienste auszubauen. Dazu bedarf es allerdings möglichst flexibler Dienstumgebungen, die die Kooperation zwischen Dienstanbietern und Nutzern aus unterschiedlichsten Domänen durch Unterstützung geeigneter Werkzeuge und Mechanismen fördert. Im Rahmen dieser Dissertation definieren wir aufbauend auf Forschungsergebnisse im Bereich Overlay-Netze, Netzabstraktion und Zugriff auf exponierte Dienste eine Service Broker genannte Dienstumgebung für konvergente Internet- und Telekommunikationsdienste. Dieser Service Broker stellt Mechanismen für die Komposition von Diensten und Mediation zwischen unterschiedlichen Dienstparadigmen und Domänenspezifika beim Dienstaufruf zur Verfügung. Der Forschungsbeitrag dieser Arbeit findet auf unterschiedlichen Ebenen statt: Aufbauend auf einer Analyse und Klassifikation von Technologien und Paradigmen aus den Bereichen Informationstechnologie (IT) und Telekommunikation diskutieren wir die Problemstellung der Kooperation von Diensten und deren Komposition über Domänengrenzen hinweg. In einem zweiten Schritt diskutieren wir Methoden der Dienstkomposition und präsentieren eine formalisierte Methode der modellbasierten Diensterstellung. Der Schwerpunkt der Arbeit liegt auf der Spezifikation der Service Broker Dienstumgebung und einem zugrundeliegenden Informations- und Datenmodell. Diese Architektur erlaubt die Komposition und Kooperation von Diensten über Domänengrenzen hinweg, um konvergente Internet- und Telekommunikationsdienste zu realisieren. Hierfür wird ein auf Obligationspolitiken basierendes Regelsystemformalisiert, das Interaktionen zwischen Dienstmerkmalen während der Diensterstellung und -ausführung definiert.
106

The Impact of Regulation and Competition on the Adoption of Fibre-Based Broadband Services: Recent Evidence from the European Union Member States

Briglauer, Wolfgang 07 1900 (has links) (PDF)
Fibre deployment of next-generation high-speed broadband networks is considered to be a decisive development for any information-based society, yet investment activities and especially the adoption of fibre-based broadband services take place only very gradually in most countries. This work identifies the most important determinants of the adoption of fibre-based broadband services, using the most recent panel data from the European Union member states (EU27) for the years from 2004 to 2012. The results show that the stricter previous broadband access regulation has a negative impact on adoption, while competitive pressure from mobile networks affects adoption in a non-linear manner. It appears that the approach of strict cost-based access regulation embedded in the EU regulatory framework is at odds with the targets outlined in the European Commission's "Digital Agenda". Finally, we also find strong evidence for network effects underlying the adoption process. (author's abstract) / Series: Working Papers / Research Institute for Regulatory Economics
107

The Impact of Regulation and Competition on the Adoption of Fiber-based Broadband Services: Recent Evidence from the European Member States

Briglauer, Wolfgang 01 1900 (has links) (PDF)
Although fibre-deployment of next generation access (NGA) broadband networks is considered as a decisive development for any information-based society, investment activities and especially the adoption of fiber-based broadband services take place only very gradually in most countries. This work identifies the most important determinants of NGA broadband adoption, using most recent panel data from the European Union member states (EU27) for the years from 2004 to 2012. The results show that stricter previous broadband access regulation has a negative impact on NGA adoption, while competitive pressure from mobile networks affects NGA adoption in a non-linear manner. It appears that the approach of strict cost-based access regulation embedded in the EU regulatory framework is at odds with the ambitious targets outlined in the European Commission´s "Digital Agenda". Finally, we find strong evidence for network effects underlying the NGA adoption process. (author's abstract) / Series: Working Papers / Research Institute for Regulatory Economics
108

The Impact of Regulation and Competition on the Adoption of Fiber-based Broadband Services: Recent Evidence from the European Member States

Briglauer, Wolfgang 01 1900 (has links) (PDF)
Fibre deployment of next-generation high-speed broadband networks is considered to be a decisive development for any information-based society, yet investment activities and especially the adoption of fibre-based broadband services take place only very gradually in most countries. This work identifies the most important determinants of the adoption of fibre-based broadband services, using the most recent panel data from the European Union member states (EU27) for the years from 2004 to 2012. The results show that the stricter previous broadband access regulation has a negative impact on adoption, while competitive pressure from mobile networks affects adoption in a non-linear manner. It appears that the approach of strict cost-based access regulation embedded in the EU regulatory framework is at odds with the targets outlined in the European Commission's "Digital Agenda". Finally, we also find strong evidence for network effects underlying the adoption process. (author's abstract) / Series: Working Papers / Research Institute for Regulatory Economics
109

Production automatique de modèles tridimensionnels par numérisation 3D / Automatic production of three-dimensionnel models by 3D digitization

Khalfaoui, Souhaiel 19 November 2012 (has links)
La numérisation 3D telle que pratiquée aujourd'hui repose essentiellement sur les connaissances de l'opérateur qui la réalise. La qualité des résultats reste très sensible à la procédure utilisée et par conséquent aux compétences de l'opérateur. Ainsi, la numérisation manuelle est très coûteuse en ressources humaines et matérielles et son résultat dépend fortement du niveau de technicité de l'opérateur. Les solutions de numérisation les plus avancées en milieu industriel sont basées sur une approche d'apprentissage nécessitant une adaptation manuelle pour chaque pièce. Ces systèmes sont donc semi-automatiques compte tenu de l'importance de la contribution humaine pour la planification des vues.Mon projet de thèse se focalise sur la définition d'un procédé de numérisation 3D automatique et intelligente. Ce procédé est présenté sous forme d'une séquence de processus qui sont la planification de vues, la planification de trajectoires, l'acquisition et les post-traitements des données acquises. L'originalité de notre démarche de numérisation est qu'elle est générique parce qu'elle n'est pas liée aux outils et méthodes utilisés pour la réalisation des tâches liées à chaque processus. Nous avons également développé trois méthodes de planification de vues pour la numérisation d'objets sans connaissance a priori de leurs formes. Ces méthodes garantissent une indépendance des résultats par rapport au savoir-faire de l'opérateur. L'originalité de ces approches est qu'elles sont applicables à tous types de scanners. Nous avons implanté ces méthodes sur une cellule de numérisation robotisée. Nos approches assurent une reconstruction progressive et intelligente d'un large panel d'objets de différentes classes de complexité en déplaçant efficacement le scanner / The manual 3D digitization process is expensive since it requires a highly trained technician who decides about the different views needed to acquire the object model. The quality of the final result strongly depends, in addition to the complexity of the object shape, on the selected viewpoints and thus on the human expertise. Nowadays, the most developed digitization strategies in industry are based on a teaching approach in which a human operator manually determines one set of poses for the ranging device. The main drawback of this methodology is the influence of the operator's expertise. Moreover, this technique does not fulfill the high level requirement of industrial applications which require reliable, repeatable, and fast programming routines.My thesis project focuses on the definition of a procedure for automatic and intelligent 3D digitization. This procedure is presented as a sequence of processes that are essentially the view planning, the motion planning, the acquisition and the post-processing of the acquired data. The advantage of our procedure is that it is generic since it is not performed for a specific scanning system. Moreover, it is not dependent on the methods used to perform the tasks associated with each elementary process. We also developed three view planning methods to generate a complete 3D model of unknown and complex objects that we implemented on a robotic cell. Our methods enable fast and complete 3D reconstruction while moving efficiently the scanner. Additionaly, our approaches are applicable to all kinds of range sensors.
110

Praktické využití Web Intelligence / Practical use of Web Intelligence

Hnízdil, Jan January 2010 (has links)
Web Intelligence has been quiet a popular topic lately. This thesis doesn't try to form the exact definition of Web Intelligence, because it's impossible. The aim is to demonstrate practical use of WI in retail banking instead. Since Web Intelligence can be seen as some kind of advanced Web Analytics system, the text starts off with explaining basics of Web Analytics. Then a hypothetical story about Mr. Cerny ' looking for a bank that would give him a mortgage loan is told. Meanwhile, a bank that provides Mr. Cerny 's current account tries to sell its own mortgage loan to him. Unfortunately, wrong channel at a wrong time is used to communicate the message which ends up with Mr. Cerny denying the offer instantly. Obvious mistakes made by the bank are then picked up and discussed. The conclusion is you need to know your customer very good to have long and healthy relationship. One way to achieve this is to deployWeb Intelligence solution that would reveal online habits of every one of your customers. Event Driven Marketing online campaigns can then be used to identify customers needs and target them at the right time, through the right channel and with the right message. If everything works well, the customer starts to percieve marketing communication as a personal support rather than annoying advertisement.

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