Die Dozenten der Informatik-Institute der Technischen Universität
Braunschweig laden im Rahmen des Informatik-Kolloquiums zu folgendem
Vortrag ein:
Dr. Stephan Sigg, Institut für Betriebssysteme und Rechnerverbund,
Technische Universität Braunschweig:
Feedback based distributed adaptive transmit beamforming - Algorithmic
considerations
Beginn: 31.01.2011, 17:00 Uhr
Ort: TU Braunschweig, Informatikzentrum, Mühlenpfordtstraße 23,
1.OG, Hörsaal M 160
Webseite: http://www.ibr.cs.tu-bs.de/cal/kolloq/2011-01-31-sigg.html
Kontakt: Dr. Stephan Sigg
Distributed adaptive beamforming in wireless sensor networks is the
attempt to achieve phase coherency in a transmission among a set of
distributed transmitters to a remote receiver. With this technique
it is possible to decrease the transmission power required by each
individual node, to increase the transmission range or to improve the
robustness of transmission. Traditional algorithmic solutions require
significant computational capabilities of nodes and utilise, for instance,
CDMA techniques together with Phase locked loops to each individual
transmitter. These requirements typically surcharge the computational
capabilities of simple sensor nodes. Recently, however, a computationally
cheap randomised scheme for phase synchronisation was presented in [1].
We derive an asymptotically sharp bound on the synchronisation speed of
this randomised black box optimisation technique for closed-loop feedback
based distributed adaptive beamforming in wireless sensor networks. We
also show that the feedback function that guides this synchronisation
process is weak multimodal.
Given this knowledge that no local optimum exists, we consider an
approach to locally compute the phase offset of each individual carrier
signal. With this design objective an asymptotically optimal algorithm is
derived. Additionally, we discuss the concept to reduce the optimisation
time and energy consumption by hierarchically clustering the network
into subsets of nodes that achieve beamforming successively over all
clusters. For the approaches discussed we demonstrate their practical
feasibility in simulations and experiments.
[1] R. Mudumbai, G. Barriac, and U. Madhow, "On the feasibility of
distributed beamforming in wireless networks," IEEE Trans. on Wireless
Commun., vol. 6, no. 5, pp. 1754-1763.
Die Dozenten der Informatik-Institute der Technischen Universität
Braunschweig laden im Rahmen des Informatik-Kolloquiums zu folgendem
Vortrag ein:
Prof. Dr. Holger Giese, Hasso-Plattner-Institut, Potsdam:
Model-Driven Engineering of Self-Adaptive Software
Beginn: 28.01.2011, 11:00 Uhr
Ort: TU Braunschweig, Informatikzentrum, Mühlenpfordtstraße 23,
1. OG, Hörsaal M 161
Webseite: http://www.ibr.cs.tu-bs.de/cal/kolloq/2011-01-28-giese.html
Kontakt: Dr. Michaela Huhn
While software is an immaterial object that does not decay with time,
Parnas pointed out that it is in fact aging. Lehman's laws of software
evolution accordingly states that a system that is being used undergoes
continuing adaption or degrades in effectiveness. Consequently, we
can observe that the ability to cost-effectively adapt software has
become one of the most important critical success factors for software
development today.
One particular vision to address this challenge is self-adaptive
software that incorporates the capability to adjust itself to the
changing needs into the software itself. This capability promises at
first to considerably reduce the costs for required administration
and maintenance and to avoid a decline in quality. In addition, future
generation of software systems that interconnect the today more or less
decoupled applications into complex, evolving software landscapes will
require the capability to adapt itself as an important cornerstone as
the software as whole can no longer be engineered at development time.
In this talk we want review why we should look for means to engineer
self-adaptive software systematically and what requirements have to be
fulfilled to achieve the systematic software engineering of self-adaptive
systems. Then, we will look into the particular role of models for
engineering self-adaptive systems and discuss the current vision for the
model-driven software engineering of self-adaptive systems. Besides the
means to build self-adaptive systems with models, we will also review the
role of models for the validation and verification of such systems.Der
genaue Ort des Vortrags wird noch bekannt gegeben.
Die Dozenten der Informatik-Institute der Technischen Universität
Braunschweig machen auf folgenden Vortrag der GI Regionalgruppe
Braunschweig aufmerksam:
GI-Vortrag: Prof. Dr. Ina Schiering, Ostfalia Hochschule für angewandte
Wissenschaften, Institut für angewandte Informatik:
Cloud Computing
Beginn: 20.01.2011, 18:00 Uhr
Ort: Haus der Wissenschaft, Raum Veolia, Pockelsstraße 11
Webseite: http://www.lineas.de/gi-bs/
Kontakt: Anja Schaar-Goldapp, Sprecherin der GI Regionalgruppe BS
Cloud Computing ist ein wichtiger Trend in der IT: Kunden können
IT-Ressourcen und Services flexibel nutzen und skalieren. Bekannte Cloud
Services wie Amazon Web Services, Google Apps, Microsoft Azure bieten
zudem ein attraktives, weil nutzungsabhängiges Preismodell. Damit
können Unternehmen grosse Anfangsinvestitionen in eigene IT-Projekte
vermeiden. Trotz der betriebswirtschaftlichen Vorteile haben viele
Unternehmen und Privatpersonen Bedenken, weil Cloud Services oft wenig
transparent sind.
Im Vortrag geht es darum Hintergrundinformationen für eine eigene
Einschätzung zu erhalten. Was ist eigentlich ein Cloud Service? Was
sind mögliche Betreibermodelle? Was sind Vorteile und Risken? Besonders
interessant sind hier Ansätze zum Thema Security.
Die Dozenten der Informatik-Institute der Technischen Universität
Braunschweig laden im Rahmen des Informatik-Kolloquiums zu folgendem
Vortrag ein:
Prof. Dr. Holger Giese, Hasso-Plattner-Institut, Potsdam:
Model-Driven Engineering of Self-Adaptive Software
Beginn: 28.01.2011, 11:00 Uhr
Ort: TU Braunschweig, Informatikzentrum, Mühlenpfordtstraße 23,
1. OG, Hörsaal M 161
Webseite: http://www.ibr.cs.tu-bs.de/cal/kolloq/2011-01-28-giese.html
Kontakt: Dr. Michaela Huhn
While software is an immaterial object that does not decay with time,
Parnas pointed out that it is in fact aging. Lehman's laws of software
evolution accordingly states that a system that is being used undergoes
continuing adaption or degrades in effectiveness. Consequently, we
can observe that the ability to cost-effectively adapt software has
become one of the most important critical success factors for software
development today.
One particular vision to address this challenge is self-adaptive
software that incorporates the capability to adjust itself to the
changing needs into the software itself. This capability promises at
first to considerably reduce the costs for required administration
and maintenance and to avoid a decline in quality. In addition, future
generation of software systems that interconnect the today more or less
decoupled applications into complex, evolving software landscapes will
require the capability to adapt itself as an important cornerstone as
the software as whole can no longer be engineered at development time.
In this talk we want review why we should look for means to engineer
self-adaptive software systematically and what requirements have to be
fulfilled to achieve the systematic software engineering of self-adaptive
systems. Then, we will look into the particular role of models for
engineering self-adaptive systems and discuss the current vision for the
model-driven software engineering of self-adaptive systems. Besides the
means to build self-adaptive systems with models, we will also review the
role of models for the validation and verification of such systems.Der
genaue Ort des Vortrags wird noch bekannt gegeben.
Die Dozenten der Informatik-Institute der Technischen Universität
Braunschweig laden im Rahmen des Informatik-Kolloquiums zu folgendem
Vortrag ein:
Dr. Stephan Sigg, Institut für Betriebssysteme und Rechnerverbund,
Technische Universität Braunschweig:
Feedback based distributed adaptive transmit beamforming - Algorithmic
considerations
Beginn: 31.01.2011, 17:00 Uhr
Ort: TU Braunschweig, Informatikzentrum, Mühlenpfordtstraße 23,
1.OG, Hörsaal M 160
Webseite: http://www.ibr.cs.tu-bs.de/cal/kolloq/2011-01-31-sigg.html
Kontakt: Dr. Stephan Sigg
Distributed adaptive beamforming in wireless sensor networks is the
attempt to achieve phase coherency in a transmission among a set of
distributed transmitters to a remote receiver. With this technique
it is possible to decrease the transmission power required by each
individual node, to increase the transmission range or to improve the
robustness of transmission. Traditional algorithmic solutions require
significant computational capabilities of nodes and utilise, for instance,
CDMA techniques together with Phase locked loops to each individual
transmitter. These requirements typically surcharge the computational
capabilities of simple sensor nodes. Recently, however, a computationally
cheap randomised scheme for phase synchronisation was presented in [1].
We derive an asymptotically sharp bound on the synchronisation speed of
this randomised black box optimisation technique for closed-loop feedback
based distributed adaptive beamforming in wireless sensor networks. We
also show that the feedback function that guides this synchronisation
process is weak multimodal.
Given this knowledge that no local optimum exists, we consider an
approach to locally compute the phase offset of each individual carrier
signal. With this design objective an asymptotically optimal algorithm is
derived. Additionally, we discuss the concept to reduce the optimisation
time and energy consumption by hierarchically clustering the network
into subsets of nodes that achieve beamforming successively over all
clusters. For the approaches discussed we demonstrate their practical
feasibility in simulations and experiments.
[1] R. Mudumbai, G. Barriac, and U. Madhow, "On the feasibility of
distributed beamforming in wireless networks," IEEE Trans. on Wireless
Commun., vol. 6, no. 5, pp. 1754-1763.
Die Dozenten der Informatik-Institute der Technischen Universität
Braunschweig laden im Rahmen des Informatik-Kolloquiums zu folgendem
Vortrag ein:
Prof. Wilhelm Schäfer, FG Softwaretechnik, Heinz Nixdorf Institut und
Institut für Informatik, Universität Paderborn:
Ein UML basierter Ansatz für die Modellierung, Verifikation und
Implementierung der Informationsverarbeitung in mechatronischen Systemen -
Mechatronic UML
Beginn: 07.02.2011, 17:00 Uhr
Ort: TU Braunschweig, Informatikzentrum, Mühlenpfordtstraße 23,
1.OG, Hörsaal M 160
Webseite: http://www.ibr.cs.tu-bs.de/cal/kolloq/2011-02-07-schaefer.html
Kontakt: Prof. Dr. Ursula Goltz
Am Beispiel des Projekts Neue Bahntechnik Paderborn wird der, in der
Arbeitsgruppe Softwaretechnik im Rahmen des SFB 614 entwickelte Ansatz zur
Spezifikation und Analyse der Informationsverarbeitung in mechatronischen
Systemen vorgestellt.
Der Ansatz beruht auf einem gemeinsamen hierarchischen Architekturmodell
für alle Systemkomponenten sowie einer speziellen Anpassung und
Erweiterung der UML (Unified Modelling Language) und wird MechatronicUML
genannt.
Durch hybride Schnittstellen erweiterte UML-Komponentendiagramme
unterstützen die formale Abbildung des obigen Architekturmodells sowie
eine syntaktische Konsistenzprüfung der verschiedenen Systemebenen
und die korrekte Einbettung kontinuierlicher Systembeschreibungen. Zu
Realtime-Statecharts erweiterte Statecharts, die durch eine Abbildung auf
"Timed Automata" eine formale Semantik erhalten, ermöglichen das "Model
Checking" des Systemverhaltens und damit die formale Überprüfung von
sicherheitsrelevanten Eigenschaften. Letztlich wird der Ansatz durch
die Möglichkeit mit Graphtransformationssystemen komplexere Verhalten
beschreiben zu können, erweitert.
