21 research outputs found

    Hybrid Routing in Delay Tolerant Networks

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    This work addresses the integration of today\u27s infrastructure-based networks with infrastructure-less networks. The resulting Hybrid Routing System allows for communication over both network types and can help to overcome cost, communication, and overload problems. Mobility aspect resulting from infrastructure-less networks are analyzed and analytical models developed. For development and deployment of the Hybrid Routing System an overlay-based framework is presented

    Hybrid routing in delay tolerant networks

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    This work addresses the integration of today\\u27s infrastructure-based networks with infrastructure-less networks. The resulting Hybrid Routing System allows for communication over both network types and can help to overcome cost, communication, and overload problems. Mobility aspect resulting from infrastructure-less networks are analyzed and analytical models developed. For development and deployment of the Hybrid Routing System an overlay-based framework is presented

    Flexible Application-Layer Multicast in Heterogeneous Networks

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    This work develops a set of peer-to-peer-based protocols and extensions in order to provide Internet-wide group communication. The focus is put to the question how different access technologies can be integrated in order to face the growing traffic load problem. Thereby, protocols are developed that allow autonomous adaptation to the current network situation on the one hand and the integration of WiFi domains where applicable on the other hand

    Next Generation Service Delivery Platforms and Service Overlay Networks

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively

    Emerging research directions in computer science : contributions from the young informatics faculty in Karlsruhe

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    In order to build better human-friendly human-computer interfaces, such interfaces need to be enabled with capabilities to perceive the user, his location, identity, activities and in particular his interaction with others and the machine. Only with these perception capabilities can smart systems ( for example human-friendly robots or smart environments) become posssible. In my research I\u27m thus focusing on the development of novel techniques for the visual perception of humans and their activities, in order to facilitate perceptive multimodal interfaces, humanoid robots and smart environments. My work includes research on person tracking, person identication, recognition of pointing gestures, estimation of head orientation and focus of attention, as well as audio-visual scene and activity analysis. Application areas are humanfriendly humanoid robots, smart environments, content-based image and video analysis, as well as safety- and security-related applications. This article gives a brief overview of my ongoing research activities in these areas

    Fiber Channel Vs. Internet Scsi On Storage Area Networks For Disaster Recovery Operations

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    Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2006Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2006Bu tez çalışmasında iSCSI tabanlı veri depolama ağlarının performansının iyileştirilmesi için iSCSI ve TCP katmalarının birbiriyle etkileşimi incelenmektedir. Bu inceleme neticesinde en uygun iSCSI ve TCP parametre değerleri belirlenmeye çalışılmıştır. Uygun parametre değerleri kullanılarak optimize edilmiş bir iSCSI veri depolama çözümünün Fiber Kanal tabanlı veri depolama çözümlerine alternatif olabileceği gösterilmeye çalışılmıştır.This thesis examines the interactions between the iSCSI and TCP layer in order to improve the performance of iSCSI-based storage system. As a result of this study, the most proper iSCSI and TCP parameter values were supposed to be determined. By using these proper parameter values, it was tried to be shown that an optimized iSCSI-based storage solution with suitable parameters can be an alternative to FC-based storage solutions.Yüksek LisansM.Sc

    P2P and SOA architecture for digital libraries

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    Doutoramento em Engenharia InformáticaIn an information-driven society where the volume and value of produced and consumed data assumes a growing importance, the role of digital libraries gains particular importance. This work analyzes the limitations in current digital library management systems and the opportunities brought by recent distributed computing models. The result of this work is the implementation of the University of Aveiro integrated system for digital libraries and archives. It concludes by analyzing the system in production and proposing a new service oriented digital library architecture supported in a peer-to-peer infrastructureNuma sociedade em que o volume e o valor da informação produzida e disseminada tem um peso cada vez maior, o papel das bibliotecas digitais assume especial relevo. O presente trabalho analisa as limitações dos actuais sistemas de gestão de bibliotecas digitais e as oportunidades criadas pelos mais recentes modelos de computação distribuída. Deste trabalho resultou a implementação do sistema integrado para bibliotecas e arquivos digitais da Universidade de Aveiro. Este trabalho finaliza debruçando-se sobre o sistema em produção e propondo uma nova arquitectura de biblioteca digital sustentada numa infrastrutura peer-to-peer e orientada a serviços

    A Novel Predictor Based Framework to Improve Mobility of High Speed Teleoperated Unmanned Ground Vehicles

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    Teleoperated Unmanned Ground Vehicles (UGVs) have been widely used in applications when driver safety, mission eciency or mission cost is a major concern. One major challenge with teleoperating a UGV is that communication delays can significantly affect the mobility performance of the vehicle and make teleoperated driving tasks very challenging especially at high speeds. In this dissertation, a predictor based framework with predictors in a new form and a blended architecture are developed to compensate effects of delays through signal prediction, thereby improving vehicle mobility performance. The novelty of the framework is that minimal information about the governing equations of the system is required to compensate delays and, thus, the prediction is robust to modeling errors. This dissertation first investigates a model-free solution and develops a predictor that does not require information about the vehicle dynamics or human operators' motion for prediction. Compared to the existing model-free methods, neither assumptions about the particular way the vehicle moves, nor knowledge about the noise characteristics that drive the existing predictive filters are needed. Its stability and performance are studied and a predictor design procedure is presented. Secondly, a blended architecture is developed to blend the outputs of the model-free predictor with those of a steering feedforward loop that relies on minimal information about vehicle lateral response. Better prediction accuracy is observed based on open-loop virtual testing with the blended architecture compared to using either the model-free predictors or the model-based feedforward loop alone. The mobility performance of teleoperated vehicles with delays and the predictor based framework are evaluated in this dissertation with human-in-the-loop experiments using both simulated and physical vehicles in teleoperation mode. Predictor based framework is shown to provide a statistically significant improvement in vehicle mobility and drivability in the experiments performed.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/146026/1/zhengys_1.pd
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