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Static Analysis of Computer Networks
Hozza, Tomáš ; Veselý, Vladimír (referee) ; Ryšavý, Ondřej (advisor)
Some problems in configurations of network devices are difficult to identify. Access control lists present an important part of many configurations. Conflicts among rules of an access control list can cause holes in security policy or quality of service. In this paper we focus on identifying and classifying conflicts among rules of an access control list. Discovering all possible types of conflicts is not a trivial task. We present optimized algorithm for complete access control list analysis using tries, based on existing research by Baboescu and Varghese. The tool for detecting conflicts among access control list rules of one given Cisco, HP or Juniper device using tries based algorithm has been implemented. Bit vectors in tries use WAH compression method to reduce memory consumption. Implemented tool was tested for correctness and performance. The hypothesis that this solution would make the analysis of access lists significantly faster has been proven.
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Dynamic Data Race Detection and Self-Healing in Java Programs
Letko, Zdeněk ; Kolář, Dušan (referee) ; Vojnar, Tomáš (advisor)
Finding concurrency bugs in complex software is difficult. As a contribution to coping with this problem the thesis proposes an architecture for a fully automated dynamic detection and healing of data races and atomicity violations in Java. Two distinct algorithms for detecting of data races are presented. One of them is a novel algorithm called AtomRace which detects data races as a special case of atomicity violations. The healing is based on suppressing a recurrence of the detected problem and can be performed by introducing an additional synchronization or by legally influencing the Java scheduler. Basically forces certain parts of the code to be executed atomically. The proposed architecture uses bytecode instrumentation to be able to track and influence the execution. The architecture and algorithms were implemented and tested on multiple case studies.
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Material nonlinear solution of structures made of plastics
Weis, Lukáš ; Krejsa,, Martin (referee) ; Králík,, Juraj (referee) ; Kytýr, Jiří (referee) ; Němec, Ivan (advisor)
The presented thesis focuses on static analysis of plastic structures, taking into account nonlinear behaviour of the material depending on the stress. The static analysis is performed using the finite element method. The difference between material linear and material nonlinear approach is illustratively described in the introduction. A shell finite element, which is enhanced by the possibility of further delamination into layers and integration points along its thickness, is suitable to be used for a numerical analysis of a plastic structures. Separate chapters are devoted to the integration of the resulting values over the height of the cross-section. The integration of the material stiffness matrix correctly reflects the emergence of eccentricity. A part of the attention is devoted to the numerical quadrature rules. Next chapter is devoted to material nonlinear models. Two approaches are described: a simpler one, using the isotropic nonlinear elastic model, and more general one, using the orthotropic plastic model. The theoretical description is complemented by the graphic interpretation of the criteria according to the individual authors. A significant portion of this work is devoted to the algorithmization of calculation procedures described in the theoretical chapters. The algorithmization itself is implemented in Fortran language into a dynamic-link library which is part of the software program RFEM 5 which is widely used in engineering practice. A part of the work is a study comparing the performance of the different technologies applicable for the algorithmization of the described issues. The agreement of the theoretical analysis of the material models and subsequent implementation within the RFEM 5 is demonstrated on the example of the bent cantilever. The thermoplastic aboveground tank structure is subject of detailed material linear, and nonlinear analysis respectively. The various approaches are compared on the results of stress, deformation an
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High loading shovel for telehandlers LM1345 Turbo
Dragan, Lukáš ; Kubín, Martin (referee) ; Škopán, Miroslav (advisor)
This diploma thesis follow up the structural design high loading shovel for telehandlers LM1345 TURBO by New Holland. The introduction processed basic characteristics and parameters of the machine and material which will be in operation most frequently transported by the shovel. The work includes static analysis load acting on the shovel and frame when the machine is operating, strength calculations and the design and control of the peg.
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Modification of Aluminium Cooler Holder
Malovaný, Daniel ; Ramík, Pavel (referee) ; Svída, David (advisor)
The purpose of this thesis is to overview the basic design solutions of full aluminum radiators. By finite element method to check the first generation of full aluminum low temperature radiator bracket and based on this calculation to modify the design to reduce tension in the critical areas. At the end of this thesis to evaluate the new design.
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High loading shovel
Petro, Roman ; Lžičař, Roman (referee) ; Škopán, Miroslav (advisor)
This diploma thesis solves construction project high dumping shovel for back hoe loader New Holland B100 and B110. There are described operating conditions in the introduction, transport material and technical parameters for back hoe loader B100, B110. There are mentioned possible construction’s solutions and own design. Follow the kinematics analysis of material’s dumping and the static analysis on shovel and frame. This is connected with following peg’s control and the solidity analysis of shovel and frame for different load cases, where the MFE was used
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Hydraulic and mechanical holding device of front shovel of excavator LB 115
Bělov, Pavel ; Lžičař, Roman (referee) ; Škopán, Miroslav (advisor)
This Diploma thesis solves a quick coupler design for a loader. In introduction of the Diploma thesis are mentioned two potential designes and convenient solutions. Subsequently are outlined two practicable designes of a quick coupler for a original bucket, as a data componant of the second construction design is enclosed basic strength calculation. The ending point of the thesis deals and compare with the force decrease in use of a quick coupler and appraisals achieved ascertainment.
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London Eye
Hušek, Martin ; Hradil, Petr (referee) ; Zídek, Rostislav (advisor)
Performance of static analysis of the London Eye structure is the subject of this diploma thesis. First chapters of the thesis analyses overview of realized structures of the Ferris wheel. The main part of the thesis analyses the London Eye structure itself. Specifically are described response analyses, sensitivity analyses, analyses of ultimate limit state and serviceability, stress analyses, analyses of fatigue stress and lifetime analyses. The thesis describes among static analysis also a design of dynamic vibration absorbers. The results of each analysis are evaluated in the final chapters.
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Survey and Assessment of Masonry Buildings before Modernization
Stanislav, Štěpán ; Kocáb, Dalibor (referee) ; Cikrle, Petr (advisor)
This thesis deals with the exploration and evaluation of historic masonry building. The researched building was built in the 20th 20th century. Is located in the premises of the Philosophical Faculty of Masaryk University in Brno. During preparation for the planned modernization of the survey was conducted several objects of the university complex. In this work, however, we consider only the building named "C". It will be processed by selected diagnostic method. The findings will then serve as a basis for static analysis and follow-up activities associated with modernization.
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Dynamic analysis of steel tank with liquid
Farkasová, Zuzana ; Mrózek, Michal (referee) ; Hradil, Petr (advisor)
Master´s thesis deals with dynamic analysis of steel tank with liquid. There are given parametres of structure and thein introduction to ANSYS system. There are created three numerical models for comparison, which are static and modal analysis calculated for. Spectrum analysis is calculated only for numerical models with fluid elements. Shell elements are evaluated according to EC 3.
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