Campusleben_HAW_Hamburg_28

Lehrende_HAW_Hamburg_9

Studierende_HAW_Hamburg_24

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Publikationen von Professorinnen und Professoren der HAW Hamburg

Jahr:  
Alle : 1982, ... , 2010, 2011, 2012, ... , 2019
Autor:  
Alle : A, À, B, C, D, E, F, G, H, I, J, K, L, M, N, O, Ö, P, Q, R, S, T, U, V, W, Y, Z 
Alle : W. Biersack, ... , Wetzel, Weyand, Weyhe, ... , Wöste 
Präferenzen: 
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Referenzen

Zeitschriftenbeiträge:

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U. Hoffmeister, M. Bullinger, A. van Egmond-Fröhlich, C. Goldapp, R. Mann, U. Ravens-Sieberer, T. Reinehr, Joachim Westenhöfer, N. Wille und R.W. Holl
Übergewicht und Adipositas in Kindheit und Jugend. Evaluation der ambulanten und stationären Versorgung in Deutschland in der „EvAKuJ-Studie“
Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz, 54:128-35
2011
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Simon Guentner und Uwe-Jens Walther
Zurück auf Los? Das Programm Soziale Stadt in seinem zweiten Jahrzehnt
vhw Forum Stadtentwicklung, (1):15-19
2011

Marker: WS-SozA

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Thomas C. Schmidt, Matthias Wählisch, Markus de Brühn und Thomas Häberlen
Ein Routing-Atlas für die strukturelle und visuelle Exposition des deutschen Internets
Praxis der Informationsverarbeitung und Kommunikation (PIK), 34(2):60--72
2011

Marker: TI-I

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Thomas C. Schmidt, Gabriel Hege, Matthias Wählisch, Hans L. Cycon, Mark Palkow und Detlev Marpe
Distributed SIP Conference Management with Autonomously Authenticated Sources and its Application to an H.264 Videoconferencing Software for Mobiles
Multimedia Tools and Applications, 53(2):349--370
2011

Marker: TI-I

Zusammenfassung: The design of conferencing systems for achieving efficient and flexible communication in a fully distributed, infrastructure-independent fashion is a promising direction, both in terms of research and practical development. In the particular case of video communication, the seamless adaptation to heterogeneous mobile devices poses an additional strong challenge to those seeking for interoperable and easy-to-deploy solutions. In this paper, we make several contributions towards a generic peer-to-peer (P2P) videoconferencing solution that extends into the mobile realm. We describe the essential building blocks for conference management and media distribution that are necessary for a distributed conferencing approach. Establishing a distributed SIP conference focus, participants share the conference according to their individually given capabilities and resources in terms of bandwidth and processing power rather than in a centralized and fixed way. Overall concepts and SIP-primitives for such an autonomous organization are presented. Security issues that derive from this decentralized identity management are resolved by so-called \em Overlay AuthoCast, a novel use of cryptographically generated identifiers. Furthermore, this work is dedicated to the development of a software-based H.264 video codec implementation and the specific aspects resulting from tuning such a highly resource-intensive software codec to the given target platform of a standard consumer smartphone.

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Hans L. Cycon, Thomas C. Schmidt, Matthias Wählisch, Detlev Marpe und Martin Winken
A Temporally Scalable Video Codec and its Applications to a Video Conferencing System with Dynamic Network Adaption for Mobiles
IEEE Transactions on Consumer Electronics, 57(3):1408--1415
2011

Marker: TI-I

Zusammenfassung: In this paper we present a multipoint video conferencing system that adapts to heterogeneous members including mobiles. The system is built upon a low complexity scalable extension of our H.264 codec DAVC, and a congestion-aware dynamic adaptation layer. We show that our temporally scaled video codec DSVC has the same RD performance as the non-scaled version with comparable configuration. We achieve this by QP cascading, i.e., assigning gradually refining quantization parameters to the declining temporal layers. The different quantization of frames does not lead to visually distinguishable quality fluctuations. We also present and analyze a mobile-compliant version of DSVC at reduced complexity that still admits comparable performance. Finally, we report on early work of dynamic layer tuning. Derived of delay variation measures, senders exploit scalable video layering to adapt the video transmission to varying network conditions. Initial results indicate that video performance remains close to optimal.

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Matthias Wählisch, Thomas C. Schmidt und Georg Wittenburg
On Predictable Large-Scale Data Delivery in Prefix-based Virtualized Content Networks
Computer Networks, 55(18):4086--4100
2011

Marker: TI-I

Zusammenfassung: IPTV, software replication, and other large scale content distribution services urge the need for fast and efficient content delivery mechanisms in underlay as well as overlay networks. Multicast, the natural approach on the network layer, has not been deployed globally, and solutions are pushed to the application layer. For a flexible, sustainable deployment the distribution mechanisms in use should scale up to many thousand group members and provide predictable performance to dynamically adjust to actual performance requirements. In this paper, we present a rigorous analytical model complemented by extensive simulations for content delivery on prefix-based overlay trees. We examine BIDIR-SAM, a generic multicast distribution scheme guided by prefixes that allow for late next-hop binding. Our evaluation quantitatively substantiates all major performance aspects. We derive the distribution functions of hop counts, packet replication loads, as well as all relevant cost measures, which scale logarithmically with network and receiver sizes. Prefix-based content delivery exhibits a churn resistance similar to the underlying key-based routing layer and a multicast efficiency scaling factor close to native group communication protocols. These results make the approach especially suitable for large and very large content groups.

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Thomas C. Schmidt, Matthias Wählisch, Benjamin Jochheim und Michael Gröning
WiSec 2011 Poster: Context-adaptive Entropy Analysis as a Lightweight Detector of Zero-day Shellcode Intrusion for Mobiles
ACM SIGMOBILE Mobile Computing and Communications Review (MC2R), 15(3):47--48
2011

Marker: TI-I

Konferenz, Symposium, Vortragsreihe, Einzelausstellung, Modenschau, Künstl. Leitung (als Ausrichter):

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Th. Willner
3rd generation biofuels – HAW Hamburg`s applied research on direct liquefaction of biomass
International DAAD Journalist Meeting, HAW Hamburg

Marker: DMI- Information

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Th. Willner
Thermochemische Direktverflüssigung
. ProcessNet Fachtagung „Alternative Brenn- und Kraftstoffe“ (Leitung Th. Willner, K. Lucka), Frankfurt/Main

Marker: LS-VT

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Th. Willner
Verflüssigung von Biomasse
. 5. Life Science Day in Bergedorf zum Thema „Erneuerbare Energien”, HAW Hamburg

Marker: LS-VT

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Letzte Änderung: 23.01.15

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