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Control and data structures in programming languages
Janeček, Jan ; Smrž, Jaroslav (referee) ; Dvořák, Jiří (advisor)
The essence of this work is to give basic information about the algorithm development and general pieces of knowledge of the structures in programming languages. These pieces of knowledge are specified for selected programming languages, to comparison is performed and application examples based on specific patterns for corresponding language are presented.
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Hydration of biomolecules
Flimel, Karol ; Janeček, Jiří (referee) ; Kučerík, Jiří (advisor)
The aim of this thesis was to apply methods of thermal analysis (differential scanning calorimetry and termogravimetry) to study kinetics of water evaporation from hyaluronan. This approach allowed to determine the changes of desorption energies in the course of evaporation and consequently helped to improve the understanding of the hyaluronan hydration. Thermoanalytical methods in combination with model-free kinetics previously suggested by Ozawa were used to determine kinetic parameters of studied processes. Results confirmed previous knowledge about the content of water located in primary hydration shell of hyaluronan, i.e. concentration range from 0.4 – 0.8 g of water per 1 g of hyaluronan. Further, it was found out that during the evaporation in this concentration range, the hyaluronan gel, stabilized probably by hydrogen bonds, is formed.
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Trust Management Systems in P2P Networks
Novotný, Miroslav ; Zavoral, Filip (advisor) ; Janeček, Jan (referee) ; Fujita, Satoshi (referee)
The architecture of certain class of services, such as distributed computing, distributed storages or content delivering networks shifts from the traditional client-server model to more scalable and robust peer to peer networks. Providing proper protection to such complex, open and anonymous systems is very complicated. Malicious peers can cooperate and develop sophisticated strategies to bypass existing security mechanisms. Recently, many trust management systems for P2P networks have been proposed. However, their effectiveness is usually tested only against simple malicious strategies. Moreover, a complex comparison of resistance of a particular method is missing. In this thesis, we (1) propose a new trust management system called BubbleTrust and (2) develop a simulation framework for testing trust management systems against various malicious strategies. Our simulation framework defines several criteria which determine the success of each malicious strategy in the network with a given system. We present results of four trust management systems that represent main contemporary approaches and BubbleTrust.
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Automated verification of software
Šerý, Ondřej ; Plášil, František (advisor) ; Janeček, Jan (referee) ; Ghezzi, Carlo (referee)
Despite the research e ort being invested into the eld of automated veri cation of software, its adoption in industry is still rather slow. Several reasons for this hesitation may be identi ed. The thesis focuses on the following two (i) dificulty of assessment of di erent tools, and (ii) difficulty of tools usage and integration in the development process. To facilitate tool assessment, we provide a comprehensive overview of code model checking techniques with evaluation based on a common set of criteria. In addition, we contribute by an industrial case study on applicability of the BLAST model checker. Since also proper education is necessary for the ability of tool assessment, we include our experience report on preparation of two master-level formal method courses. By incorporating an easy to use speci cation language into the BLAST model checker, the thesis contributes to facilitating tools usage. In addition, we introduce the concept of unit checking, a combination of unit testing and code model checking, which helps integration of code model checking in the software development process.
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Universality in Amorphous Computing
Petrů, Lukáš ; Wiedermann, Jiří (advisor) ; Janeček, Jan (referee) ; Neruda, Roman (referee)
Amorphous computer is a theoretical computing model consisting of randomly located tiny devices (called nodes) in some target area. The nodes of an amorphous computer can communicate using short-range radio. The communication radius is small compared to the size of the target area. The nodes are all identical, initially have no identi ers, work asynchronously and there is no standard communication protocol. An amorphous computer must work for any number of nodes under reasonable statistical assumptions concerning the spatial distribution of nodes. Moreover, the computation should use very limited amount of memory on each node. For the just described concept of amorphous computer we investigate the question whether a universal computation is possible at all in a corresponding theoretical model. To answer this question, several subsequent steps are performed. In the rst step, we design a formal minimalist model of a node and of the amorphous computer as a whole. In the second step, we develop communication protocol for the amorphous computer. In the last step, we show the universality by simulating a computation of a universal machine. The size of the amorphous computer will depend on the space complexity of the simulated machine. All the previously mentioned steps are described in detail in this work....
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Security in wireless networks
Mlčochová, Ivana ; Janeček, Jan (advisor) ; Peterka, Jiří (referee)
The more the popularity of wireless networks grows the more threatsb appear of being attacked or misused, either intentionally or by accident. This bachelor work describes security protocols in use, such as WEP, WPA and WPA2, analyses their vulnerabilities and discusses the danger of possible attacks against them. As the security protocol itself cannot entirely protect any wireless network there are additional security measures suggested that minimize the risk of an successful attack. One of the goals was to prove experimentaly that WEP is really as bad a protocol as it is said and should not be used for securing any networks not even the home ones. In connection with that a survey has been made examining how wireless networks in Prague are secured, what protocols are used. This survey showed an alarming fact that most wireless networks are still using deprecated protocol WEP or no security protocol at all.
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Aktivní XML
Ignáth, Štefan ; Janeček, Jan (advisor) ; Nečaský, Martin (referee)
This work is concerned about the usage of so called active XML for the implementation of distributed algorithms. The active XML is introduced in the form of Web Services and the XML-RPC protocol. Both of these technologies are based on the exchange of XML-based messages. While the XML-RPC protocol is nowadays an unused and almost forgotten technology, the Web Services are getting more and more attention over the last few years. The communication of Web Services is based on the exchange of SOAP messages. The interface of these services is described by WSDL files. Besides the description of these already mentioned technologies, this thesis is concerned with possible modifications of these technologies in order to implement distributed algorithms. Since the requirements of distributed algorithms, as they are conceived by the academics, are diametrically different from the requirements of business applications, for which were the Web Services developed, great compromises are necessary. The practical part of this work points at possible solutions for the usage of Web Services in the distributed algorithm computing on an exemplary implementation. Another distributed algorithm is implemented with the usage of the XMLRPC protocol and the comparison of these implementations is done.
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Connector-based Performance Data Collection for Component Applications
Bulej, Lubomír ; Tůma, Petr (advisor) ; Janeček, Jan (referee) ; Murphy, John (referee)
In this work, we propose a generic approach to collection of performance data for hetero-geneous component-based applications with the aim to provide easier and less costly access to performance data needed for measurement and model-based performance analysis of component applications. The technical foundation for the approach is built on generic solutions to various aspects of performance data collection and is made of three parts. The first part provides a design of a generic measurement infrastructure which handles common performance measurement tasks and allows collecting arbitrary performance data in response to performance events. The second part proposes using architecture-based connectors for instrumentation of component applications and provides a design of a performance instrumentation connector element for use with the measurement infrastructure. The third part proposes integration of connectors into deployment process of component applications which enables deployment and transparent instrumentation of heterogeneous component-based applications.
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