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Digital Steganography for Executables
Tobiáš, Pavel ; Bidlo, Michal (referee) ; Strnadel, Josef (advisor)
This bachelor's thesis concerns itself with steganographic concealment of arbitrary data in executable files . Initially it speaks in general terms , mainly about injection - and substitution - based steganographic methods for various types of cover - objects . Afterwards , the focus is on executable files in the ELF format and the x86 ISA family ; permutation - based methods for instructions and basic block chains are mentioned and the substitution - based method of instruction equivalence classes is examined . Consequently , the design, implementation , testing and optimization of a custom solution based on the last mentioned method are described . Finally , the methods and outcomes of experimenting with the custom solution are described .
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Development of chemically resistant sprayed mixture
Hermann, Radek ; Dohnálek,, Pavel (referee) ; Drochytka, Rostislav (advisor)
Production wastes for which a direct use in another production is found become secondary raw materials. There are several institutions in Czech Republic and in the world, which are currently dealing with the issue. This thesis deals with the issue of cementitious spray concrete mixtures and deals with the possibilities of using secondary raw materials and waste from production as partial replacement of binder and filler in these mixtures. The aim of this theses is to optimize the composition of additives in the recipe of the commercially produced pray mixture and to verify the influence of the degree of substitution of binder or filler by secondary raw materials on its physical-mechanical properties. The aim is to maintain or increase these properties while substituting the binder and filler as much as possible. After the evaluation of results, it is possible to say, by suitable optimization of the additives it is possible to achieve a significant improvement of the physical-mechanical properties of the mass and furthermore, from the results of this thesis follows, that by substitution of 100% fine filler in combination with substitution of 30% binder it is possible to maintain or increase the physical-mechanical properties after 28 days of curing and to significantly increase these properties after 90 days of curing. The results of this thesis are also related to the reduction of economic impact on production of the spray mixture, mainly due to the use of secondary raw materials.
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Library of Algorithms for Text Ciphering
Vozák, Petr ; Řezníček, Ivo (referee) ; Kubíček, Radek (advisor)
p, li { white-space: pre-wrap; } p, li { white-space: pre-wrap; } This thesis deals with text ciphering. The presented paper describes at first basic theoretical background of cryptology and basic distribution of cryptographic algorithms. Then it describes a brief history of encryption from beginning to present. Theoretical description of ciphering methods and its implementation details are discussed here. All basic types of conventional encryption algorithms and also some modern ciphering methods are included; these are substitution, transposition, steganographic or combinations encryption systems. The result of this thesis is the library of algorithms for text ciphering in Java with a sample application, which demonstrates its funcionality.
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Specific cement composite based on secondary raw materials with emphasis on durability
Figala, Petr ; Dohnálek,, Pavel (referee) ; Drochytka, Rostislav (advisor)
Nowadays the attention to the utilization of secondary raw materials as a component of building materials is being paid to in the Czech Republic and in the world. This thesis deals with possibilities of using secondary raw materials as partial cement substitutes in industrial floors. The aim of this thesis is to verify the influence of cement substitution amount with secondary raw materials and their fineness of grinding on the properties of the floor surface in time and on its structure. On the basis of the acquired knowledge, the influence of the pre-treatment of the secondary raw material on the properties of the floor ceiling with an emphasis on the economic aspect was assessed. After evaluating the results, some substitution of cement in the floor screed with secondary raw materials is beneficial. The significant influence of more intensive milling of the floor screeds base on the parameters of the final floor screed was not confirmed. It seems, that it is possible to achieve very good results even when using secondary raw materials with a lower percentage of fine particles. This brings together the economic benefits of lowering the cost of a lower dose of expensive cement by using cheaper secondary raw materials, because pre-treatment of such materials does not require the use of a large amount of energy.
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Evolutionary models for evaluation of organisms relationship
Gregorová, Kateřina ; Maděránková, Denisa (referee) ; Škutková, Helena (advisor)
The work is focused on the study and description of evolutionary models for the evaluation of the evolutionary distances of DNA sequences and protein sequences in the amino acids and the codon representation. In the framework of this work was created a program that evaluates the genetic distance between DNA sequences and protein sequences for the use of some evolutionary models. The program calculates the genetic distance of the compared sequences and on the basis thereof renders the phylogenetic tree. This can be relatively easily and quickly evaluate the affinity of the organisms. For easy operation is part of the evaluation program also graphical user interface (GUI).
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The Role of Ferrous Sulphate as a Setting Regulator and a Portland Clinker Reduction Agent
Mončeková, Miroslava ; Rovnaníková, Pavla (referee) ; Drábik, Milan (referee) ; Havlica, Jaromír (advisor)
In 2003, the European Community Obligation (directive 2003/5C/EC) regulates a maximal value of soluble hexavalent chromium to 0.0002 % (per weight of dry cement). This limitation leads to modifications of the regular Portland cement by using of suitable reduction agents. Therefore, the possibilities of chromium reduction become a very actual topic. The primary goal of this work is a basic research of the ferrous sulphate influence on hexavalent chromium reduction and also its influence on Portland clinker hydration process. The reduction ability was determined by UV/VIS method. The mechanism and ferrous sulphate influence on Portland clinker hydration process was observed by isothermal calorimetry and mechanical strength tests. XRD method, SEM-EDS analysis and Raman microscopy were used for identification of formed hydration products. Study of hydration mechanism occurring in this system was focused on the divergence observations from the regular Portland cement hydration. Pore solution analysis provided significant information about chromium behavior during the hydration process (substitution and releasing). Chromium incorporation into structure of hydration products during the reduction process was also studied in the pure tricalciumaluminate system with targeted Cr6+ content. This work suggests the possible substitution of the trivalent and hexavalent chromium into structure of monosulphate (AFm) phase.
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Elastomer fillers as a potential raw material for concrete and mortar products
Jankech, Filip ; Balog, Oliver (referee) ; Bodnárová, Lenka (advisor)
To attain a sustainable development in the field of building materials, it is necessary to consider environmental, economic, and social aspects of the industrial production. This thesis addresses the first two aspects. Both theoretical and practical research were implemented in order to study the possibility to replace the commonly used RDPs, that are being used in the dry-mix mortar industry as a primary additive, with the industrially processed elastomer waste materials, such as recycled tire rubber. The review of the scientific literature processed within the theoretical research discloses the state of the art in the field of polymer modification of the mortar products and the effect of the commonly used modifiers and elastomer fillers on the performance of mortar and concrete products. The experimental research was implemented to study the possibility of the replacement of the RDPs for the elastomer fillers. The performance of fresh and hardened mortar containing various amounts of elastomer particles was studied. The results indicate, that the partial replacement could be feasible without worsening the performance of the product.
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Development of Meta-Server for Prediction of Mutations Effects on Protein Function
Lisák, Peter ; Burgetová, Ivana (referee) ; Jaša, Petr (advisor)
This bachelor thesis deals with analysis of genomic data, more specifically prediction of effects of mutations on protein function using a protein sequence or tertiary structure. The theoretical introduction describes the basics of genetics and bioinformatics and is followed by description of selected prediction tools such as SIFT, MAPP and AUTO-MUTE. A unified interface for work with different tools is proposed in the thesis. The meta-server interface allows running a computation and collecting results from one site. meta-server combines results of implemented tools and provides a consensual prediction, which is expected to be more accurate than the results from individual tools. Finally, testing of meta-server on the real data and comparisons of predictions with the experimentally obtained results are presented.
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Electrically conductive composites based on secondary raw materials
Baránek, Šimon ; Šteffan,, Pavel (referee) ; Černý, Vít (advisor)
Electroconductive composites are modern materials that are commonly used in many industries such as the construction industry among others. For example these materials can be useful as sensors for monitoring changes in constructions. The aim of this thesis is the research of electrically conductive silicate composite based on secondary raw materials. The design of this composite is based on the development of its own mixtures and experimental verification of the effect of the structure. The introduction part consists of a detailed analysis of 15 materials. Samples of the 5 fine and 2 coarse electrically conductive fillers were tested. Composite with filler Condufit C4 was selected as representative for type of fine fillers. Composite with filler Supragraphite C300 was selected as representative for type of coarse fillers. The selection of the composites was based on the impedance of the fabricated composites with these fillers. Subsequently, the individual components of the primary mixture were substituted. The cement was replaced by high-temperature fly ash in the amount of 20, 30, and 40 %, the aggregate of a similar fraction was replaced by steel sawdust, and the primary electrically conductive fillers were replaced by secondary ones in the amount of 30 and 50 %. All proposed replacements reduced the impedance of the composite. The most effective replacement for impedance reduction was replacement with waste graphite (up to 92 % reduction), which also slightly improved the mechanical properties of the composite. The result of this thesis is an optimized electrically conductive composite based on secondary raw materials with a fine type of filler with 30 % replacement by waste graphite "odpad vysavač"which achieves an impedance of 5 ohms. The partial goal of this thesis is a verification of the influence of moisture on the impedance of composites. Results are significantly affected by moisture when using the coarse type of filler, when using the fine type are not.
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Development of new grouting materials for reverse grouting of sewers
Dolák, Martin ; Dohnálek,, Pavel (referee) ; Drochytka, Rostislav (advisor)
ABSTRACT This thesis deals with the development of silicate based reverse grouts for the purpose of rehabilitation of sewers. The work also examines the possibility of substitution of basic input raw materials with secondary raw materials, meaning replacements of both filler components and binder components. As secondary raw materials, we refer to wastes from the production process which, after the necessary treatment, are used in another production. The development and experimental verification of the functionality of the developed grout was focused mainly on the use of secondary raw materials as much as possible, while maintaining or even improving its physical and mechanical properties. Based on the results of the work, it can be stated that with a 100% replacement rate of filler components in combination with 20% replacement rate of binder components, it is possible to largely maintain the properties of the material, or even optimize them. The results of the thesis also point to the possibility of reducing the economic and environmental demands of production of building materials.
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