in partial ful2llment of the requirements for the degree of

Abstract. Semantic sensor networks use declarative descriptions of sen-sors promote reuse and integration, and to help solve the difficulties of installing, querying and maintaining complex, heterogeneous sensor net-works. This paper reviews the state of the art for the semantic specifi-cation of sensors, one of the fundamental technologies in the semantic sensor network vision. Twelve sensor ontologies are reviewed and anal-ysed for the range and expressive power of their concepts. The reasoning and search technology developed in conjunction with these ontologies is also reviewed, as is technology for annotating OGC standards with links to ontologies. Sensor concepts that cannot be expressed accurately by current sensor ontologies are also discussed. 1

April 29, 2011Für UnsShe had never before seen a rabbit with either a waistcoat-pocket, or a watch to take out of it, and burning with curiosity, she ran across the field after it Lewis CarrollThe following document, written under the supervision of Dr. reviewed by:

First, I would like to thank my advisors Prof. Gal A. Kaminka and Dr. David Sarne for their excellent guidance and constant support in the past two years. I learned quite a bit about scientific research, all thanks to their great instruction. Working with them was a real pleasure, not only

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments

group and of the IAM for our various interesting discussions about all kinds of topics and for making the institute a very pleasant and friendly place to work at. Special thanks go to David Steiner, Marc Steinemann, Matthias Scheidegger, Florian Baumgartner, Ruy De Oliveira, and Attila Weyland

/2; where α = 5/3, f ∝ Re−1/4. These findings cannot be reconciled with the classic theory of the frictional drag. The classic theory provides no means of distinguishing between one type of turbulent spectrum and another, and cannot account for the existence of a “spectral link ” between the frictional drag

I declare that this thesis is my own account of my research and contains as its main content work which has not previously been submitted for a degree at any tertiary education institution.

Prüfungsbehörde vorgelegen. Darmstadt, den 30th March 2011 Massively multiplayer online games (MMOGs) are very popular nowadays, but mostly still are implemented in a client-server based approach. This thesis is part of a study on the question: Are peer-to-peer networks suitable for real time applications like

by now in favor of better performing variants. Thirdly, the usage of local search algorithms for improving the solutions constructed by the ants is very successful in practice. Finally, the integration of other techniques such as constraint programming, tree search techniques or multi-level frameworks