# Technical Reports

## A list with abstracts sorted by year - 2007

### Adaptive Approximate Similarity Searching through Metric Social Networks

by *
Jan Sedmidubský,
Stanislav Bartoň,
Vlastislav Dohnal,
Pavel Zezula,
* A full version of the paper presented at ICDE 2008. November 2007, 22 pages.

**FIMU-RS-2007-06.**
Available as *Postscript*,
**PDF**.

#### Abstract:

Exploiting the concepts of social networking represents a novel approach to the approximate similarity query processing. We present an unstructured and dynamic P2P environment in which a metric social network is built. Social communities of peers giving similar results to specific queries are established and such ties are exploited for answering future queries. Based on the universal law of generalization, a new query forwarding algorithm is introduced and evaluated. The same principle is used to manage query histories of individual peers with the possibility to tune the tradeoff between the extent of the

### Key Distribution and Secrecy Amplification in Wireless Sensor Networks

by *
Petr Švenda,
Václav Matyáš,
* November 2007, 63 pages.

**FIMU-RS-2007-05.**
Available as *Postscript*,
**PDF**.

#### Abstract:

This report targets the area of wireless sensor networks, and in particular their security. Probabilistic key pre-distribution schemes were developed to deal with limited memory of a single node and high number of potential neighbours. We present a new idea of group support for authenticated key exchange that substantially increases the resilience of an underlaying probabilistic key pre-distribution scheme against the threat of node capturing.

### LOBS: Load Balancing for Similarity Peer-to-Peer Structures

by *
David Novák,
Pavel Zezula,
* June 2007, 36 pages.

**FIMU-RS-2007-04.**
Available as *Postscript*,
**PDF**.

#### Abstract:

The real-life experience with the similarity search shows that this task is

### Strategy Synthesis for Markov Decision Processes and Branching-Time Logics

by *
Tomáš Brázdil,
Vojtěch Forejt,
* A full version of the paper presented at CONCUR 2007 July 2007, 28 pages.

**FIMU-RS-2007-03.**
Available as *Postscript*,
**PDF**.

#### Abstract:

We consider a class of finite

### Formalisms and Tools for Design and Specification of Network Protocols

by *
Jindřich Babica,
Vojtěch Řehák,
Petr Slovák,
Pavel Troubil,
Martin Zavadil,
* May 2007, 33 pages.

**FIMU-RS-2007-02.**
Available as *Postscript*,
**PDF**.

#### Abstract:

Message Sequence Charts (MSC) are a useful formalism for formalization of

### LTL model checking with I/O-Efficient Accepting Cycle Detection

by *
Jiří Barnat,
Luboš Brim,
Pavel Šimeček,
* January 2007, 20 pages.

**FIMU-RS-2007-01.**
Available as *Postscript*,
**PDF**.

#### Abstract:

We show how to adopt existing non-DFS-based algorithm OWCTY for accepting cycle detection to the I/O efficient setting and compare the I/O efficiency and practical performance of the adopted algorithm to the existing I/O efficient LTL model checking approach of Edelkamp et al. We show that while the new algorithm exhibits similar I/O complexity with respect to the size of the graph, it avoids the quadratic increase in the size of the graph of the approach of Edelkamp et al. Therefore, the absolute numbers of I/O operations are significantly smaller and the algorithm exhibits better practical performance.

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