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The analysis of Cu-Sn-Sb ternary alloy
Kučera, Jan ; Doubrava, Marek (referee) ; Jan, Vít (advisor)
This bacholor thesis deals with substituting silver-based material, currently used for experimental semi-liquid extrusion. The proposed material is from the Cu-Sb-Sn system. The theoretical part of the work deals with soldering and phase diagrams. The experimental part is devoted to the analysis of three proposed alloys from the Cu-Sb-Sn system, their structural and mechanical properties. Thermal analyzes of the alloys were performed using differential scanning calorimetry (DSC), the microstructure using a light microscope and a scanning electron microscope, and a hardness tester was also used to determine the hardness. The results are summarized in the discussion.
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Technology to remove nitrogen oxides (NOx) from flue gases for large combustion plants
Kučera, Jan ; Brummer, Vladimír (referee) ; Jecha, David (advisor)
This diploma thesis deals with selected abatement techniques of nitrogen oxides (NOx) developed for large combustion plants. The first part describes selected NOx, their properties and explains the formation during combustion. Furthermore, there is an analysis of current legal legislation regulating the issue of emission limits. The third part presents selected primary and secondary measures that are widely used. The emphasis is placed on the description of selective catalytic (SCR) and non-catalytic reduction (SNCR). Finally, the basic design of these technologies for model combustion equipment is performed. The consumption of reducing medium and the volume of the catalyst for the mentioned techniques are calculated here. The estimate of selected operating and investment costs is a part of the basic scheme.
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Application Specific Processor for Stateful Network Traffic Processing
Kučera, Jan ; Matoušek, Jiří (referee) ; Kekely, Lukáš (advisor)
This bachelor's thesis deals with the design and implementation of an application-specific processor for high-speed network traffic processing. The main goal is to provide complex system for hardware acceleration of various network security and monitoring applications. The application-specific processor (hardware part of the system) is implemented on an FPGA card and has been designed with respect to be used in 100 Gbps networks. The design is based on the unique combination of high-speed hardware processing and flexible software control using a new concept called Software Defined Monitoring (SDM). The performance and throughput of the proposed system has been verified and measured.
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Similarity Search in Network Security Alerts
Štoffa, Imrich ; Kučera, Jan (referee) ; Žádník, Martin (advisor)
Network monitoring systems generate a high number of alerts reporting on anomalies and suspicious activity of IP addresses. From a huge number of alerts, only a small fraction is high priority and relevant from human evaluation. The rest is likely to be neglected. Assume that by analyzing large sums of these low priority alerts we can discover valuable information, namely, coordinated IP addresses and type of alerts likely to be correlated. This knowledge improves situational awareness in the field of network monitoring and reflects the requirement of security analysts. They need to have at their disposal proper tools for retrieving contextual information about events on the network, to make informed decisions. To validate the assumption new method is introduced to discover groups of coordinated IP addresses that exhibit temporal correlation in the arrival pattern of their events. The method is evaluated on real-world data from a sharing platform that accumulates 2.2 million alerts per day. The results show, that method indeed detected truly correlated groups of IP addresses.
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Netdev Driver for Acceleration COMBO Cards
Tran, Dominik ; Vrána, Roman (referee) ; Kučera, Jan (advisor)
This thesis deals with the development of the network device driver for the FPGA network COMBO cards, which should enable receiving and sending packets through standard network interface of Linux kernel. CESNET is developing a device called DDoS Protector for protection against an amplification (D)DoS attacks, which uses COMBO cards to achieve high performance. A SZE2 interface is used for high speed transfers of network data between COMBO card and a controlling software application, using technique of bypassing kernel network stack and other methods. DDoS Protector has to support standard network protocols, whose implementation directly on top of the SZE2 is very difficult. Instead, using kernel network stack, which is, by default, bypassed to achieve high performance, is much easier to implement and supports all sorts of protocols. Creation of the network device driver enables us to use kernel network stack and other network applications for COMBO cards. Based on the study of SZE2 interface and driver development, I designed and then successfully implemented network device driver. Driver was tested to ensure standard protocols work. It was also tested from the performance point of view. I have also developed the same type of driver for the newer interface - NDP and an application for an accelerated packet forwarding, both of which are functional and were not part of the thesis specification.
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IPv6 Prefix Generator
Obrusník, Vojtěch ; Kučera, Jan (referee) ; Matoušek, Jiří (advisor)
Incoming deployment of IPv6 technology in larger scale requires existence of effective route lookup algorithms suitable of manipulation with long IPv6 prefixes. Development of such algorithms is dependent on an huge amount of test data sets, which do not exist at the moment. This paper is focused on design and implementation of a tool, that would be able to generate such test data sets. Study phase of IPv6 address allocation polices and analysis of currently available pieces of prefix sets took place before the implementation. Validation of results was performed by bit value and prefix length scatter measurement.
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Protection Against DoS Attacks Using P4 Language
Vojanec, Kamil ; Fukač, Tomáš (referee) ; Kučera, Jan (advisor)
This thesis focuses on reimplementation of existing DoS (Denial of Service) attack mitigation device with high-level P4 programming language. The main reason for using P4 is to enhance adaptability and functionality to different types of DoS attacks. The created device is designed in a modular way and enables easy alterations by using interchangeable components. The target platform for this thesis is an FPGA acceleration card. The work results in designing several DoS mitigation components and implementing applications composed of these components. Pats of this work have been presented at IEEE ANCS (Symposium on Architectures for Networking and Communication Systems) in September 2019 at University of Cambridge.
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Implementation of Self-Correcting Codes for 100 Gb/s Ethernet
Velecký, Jan ; Kučera, Jan (referee) ; Kekely, Lukáš (advisor)
The thesis deals with the design of entire RS-FEC layer for the 100 Gb/s Ethernet according to IEEE 802.3-2015 standard including Reed-Solomon encoder and decoder. Text clarifies mathematical basis of finite fields, linear block codes, cyclic codes and particularly Reed-Solomon codes used in design. Design of RS-FEC layer transmit side has been adjusted for implementation in COMBO network cards which use Xilinx Virtex-7 FPGA and realized in VHDL. Encoder has been optimized in several steps - as for FPGA resource usage and as for VHDL code synthesis duration. Reduction of resource usage has been achieved by using pipelining thanks to properties of cyclic codes. Synthesis duration then by creating logic of encoder on gate level on its own. Resulting implementation has been tested in simulation and it is optimized enough for usage in FPGA for Ethernet implementation. It is possible to adapt both design and implementation for 400Gb/s Ethernet which does not exist yet at the time of design.
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Performance Measurement Tool for DNS Servers
Postolka, Matěj ; Kučera, Jan (referee) ; Vrána, Roman (advisor)
Tato práce popisuje návrh a tvorbu testovacího prostředí pro měření výkonnosti DNS serverů nad transportními protokoly TCP a UDP. Obsahuje výsledky výkonnostního měření tří různých implementací autoritativních DNS serverů nad síťovým provozem složeným z různých typů DNS dotazů zaslaných pomocí různých síťových a transportních protokolů. Je provedeno srovnání výkonnosti těchto implementací.
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