List of Theses Defences in the Year 2009

Mgr. Ondřej Daněk

Summary of the thesis:

Cell, the basic building block of all living organisms, is a very complex system. The main component of a cell is its nucleus containing the genome which stores the entire information required for the construction and function of the organism. Better understanding of the roles of particular genes and proteins during the cell cycle and the ability to detect cell abnormalities are essential for early diagnosis and subsequent treatment of severe diseases such as cancer or leukemia. Hence, investigation on the spatial structure and mutual interactions of the genetic material in the cell nucleus is one of the most challenging tasks for modern molecular and cell biology.
The research in this field is performed mainly by the means of fluorescence microscopy. Modern confocal microscopes are fully automated devices capable of producing huge amounts of image data. Therefore, there is a natural demand for reliable, fast and accurate image processing methods. Even though many sophisticated methods are available, some crucial tasks are still problematic, such as the boundary extraction of cell nuclei in cell clusters and tissues.
The thesis was defended.

Mgr. Jaromír Plhák

Summary of the thesis:

The accessibility of computer graphics is one of the most important issues that assistive technology for the visually impaired meets. Up to now, most of the works in this area have been connected with tactile devices or oriented to using sound to help the user to investigate graphics. The proposed objectives of the thesis are based on the approach, that enables the user to obtain the desired information in freely choosing combinations of verbal and non-verbal form, having simultaneously full control in the way in which he or she investigate the picture.
In this context, interesting problems are connected with the annotation of pictures. The manual annotation is time consuming while the automatic annotation is still not usable due to its high error rate. It seems to be reasonable to investigate semi-automatic methods supported by graphical ontology to improve the efficiency of the image annotation. The concept of the vector graphics indicates that its annotation can be handled even more efficiently by integrating a knowledge database consisting of additional pieces of information about the annotated objects. In this area, I will focus especially on semi-automatic annotation supported by a graphical ontology and a knowledge database in relation to the problems related to the sonification.
The system for image sonification is the complementary part to the annotation system that explores the graphical data verbally using a dialogue system for the communication with the user. In this connection, the thesis will also analyse the principles for efficient exploration of colors in the image by presenting them by non-verbal sounds. The previous research indicates that the semantic color model can be exploited in this area.
Developing dialogue communication for combining both verbal and non-verbal image information is another important objective of the thesis. It seems to be reasonable to expect that the grammar evolution approach and mixed-initiative dialogue strategy implementation will enhance the efficiency of the dialog strategies.
The thesis was defended.

Mgr. Matěj Štefaník

Summary of the thesis:

The paper presents current state in field of text document clustering and introduces new method that can solve the clustering problem. This method is called KCF (Knowledge comes first) and it is a combination of methods SearchPoint and OBSA.
The thesis was defended.

Mgr. Václav Lorenc

Summary of the thesis:

The "New Approaches to Design and Development of Secure SmartCard Applications" thesis proposal deals with the security issues of applets intended for deployment in smartcards.
Currently, methods of producing secure code are known and followed in many occasions. For a specific subset of smartcards, the Java Card platform, many of these were involved to enable programmers to use well typed programming language with possible bytecode verification. As a benefit of underlying smartcard platform, the bytecode and confidential data are protected by hardware itself.
However, not only software-specific issues represent a threat for Java Card. With involvement of indirect attacks and covert channels analysis, attackers have possibilities to discover what was meant to remain hidden, getting the very detailed insight into the code and data on the card. This gives them interesting ways of possible code modifications and misuse.
The thesis proposal discusses some possible countermeasures to bytecode reverse engineering; state automata principles are considered as a way that can both prevent side-channel analysis up to certain extent and provide provable mechanism for handling communication between the card and the host PC and corresponding processing routines.
Possible approaches are mentioned and partially identified; the thesis proposes that threat of insecure code and side-channel prevention should be studied simultaneously as interconnected disciplines of the Java Card engineering process. New methodology based on state automata principles for creating and verification Java Card applets is the objective of the upcoming research.
The thesis was defended.

Mgr. Pavel Minařík

Summary of the thesis:

The work titled “Network Traffic Processing and Visualization” offers an alternative perspective of network traffic analysis and visualization domain. In contrast to the common approaches oriented to statistically significant indicators the proposed approach focuses on processing and analysing of details. The presented methods are usable in the encrypted traffic whose amount is growing continuously. The work also deals with advanced methods of NetFlow data processing (L3 traffic statistics). Achieved results including the proposed visualization method are illustrated on the real security incident example.
The thesis was defended.

Mgr. Andriy Stetsko

Summary of the thesis:

In the section 1 there is an introduction to wireless sensor networks (WSNs), which are highly distributed networks composed of a large number of tiny low-cost devices, denoted as sensor nodes, and a few general-purpose computing devices referred to as base stations.
A wireless medium exposes data to an adversary, which may eavesdrop or even alter the ongoing communication. Attacker model and taxonomy of attacks are available in the section 2. Cryptographic techniques used to secure conventional networks are not always applicable because WSNs are infrastructure-less and resource-constrained. Moreover, cryptographic techniques are not always useful because they do not take into account node compromise, which allows the adversary to extract cryptographic material, to become a “legal” network participant and to launch insider attacks. Therefore, there is a need to introduce a second line of defense – an intrusion detection system (IDS).
In the section 3 there is an analysis of the state-of-the-art in IDSs for WSNs: how they are classified, the components they can involve, what kind of detection techniques they use, the placement of the detection agents, and how the different attacks are detected.
Several open questions related to IDS development are introduced in the section 4: localization of attacks -- most of the proposed schemes detect an intrusion, but do not localize its source; software attacks -- any vulnerability in any component might be exploited to compromise all sensor nodes; placement problem -- there is a need to choose a proper IDS placement strategy in order to minimize energy consumption and maximize IDS effectiveness; usage of cryptography -- we should carefully consider what key distribution scheme to employ since it might have an impact on an IDS effectiveness; WSN economical model -- should help to find an optimal IDS for a particular WSN.
Finally, in the section 5 there is the intent of the dissertation thesis.
The thesis was defended.