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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Multiplatformní komunikace v přístupových sítích / Multiplatform communication in access networks

Novotný, Bohumil January 2017 (has links)
Doctoral thesis deals with failure detection methods in wireless access network using distributed stochastic algorithms. A new method of detecting a fault based on the push-sum algorithm has been designed and simulated. Within the scope of the work objectives, the statistical credibility of the average push-sum protocol convergence rate representative and the effect of message loss during the calculation on the robustness of the system using this protocol were compared. Based on the acquired knowledge, the ability of the protocol to mathematically derive deviations from the real average of the values in the specified topology was demonstrated and thereby the existence of an abnormality in the network has been proved or refuted.
142

Vliv stochastických selhávaní linek na protokol push-sum / Impact of stochastic link failures on push-sum protocol

Ecler, Tomáš January 2018 (has links)
This master’s thesis deals with the distributed computing and mathematical tools for modelling the distributed systems. Firstly, my attention is focused on a description of the distributed algorithms, characteristic failures for the distributed systems, and mathematical tools for an analysis of the distributed systems.The experimental part is concerned with the impact of stochastic link failures on the chosen parameters of the protocol Push-sum, namely the deviation of the final states from the average value, the convergence rate of the protocol, the distribution of the final states, and the distribution of the convergence rates. My intention is demonstrated using Matlab on a tree, a ring, a line, a star, and a fully-connected mesh topology. Was analyzed two functionalities of the protocol Push-sum, namely an estimation of the average value and an estimation of sum.
143

Problematika vyhodnocování blokovacích podmínek rozvodny pomocí GOOSE zpráv / The issue of evaluating of interlocking in substations using GOOSE messages

Ditrych, Marek January 2019 (has links)
This master thesis focuses on problematics of GOOSE messages used for evaluation of blocking conditions of substations in the electrical power plant in Opatovice (EOP). Firstly, the thesis describes the multifunctional electrical protection relay 7SJ64 as well as GOOSE messages, that are run by protocol IEC 61850. Next, it contains a brief description of the energy consumption of EOP itself, since the project was written for its protection relays. In the practical part of the thesis, an experimental network consisting of two distinct substations with three 7SJ64 multifunctional protection relays was designed together with simple blocking conditions. These require information about the state of circuit breakers. The whole communication is carried by GOOSE messages. Moreover, to inform about the loss of GOOSE messages, the logical function SI_GET_S (decoder) was used inside the coding interface of DIGSI programme called CFC. This function was then tested in the experimental network using each different condition, that experienced interruptions of communication caused either by simulated defect of optical cabels, or by „user‘s mistakes“ in the settings of communication parameters in DIGSI. Finally, the system protecting from the loss of GOOSE messages was incorporated into the existing project evaluating blocking conditions in the block substation of EOP.
144

Anonymita v P2P sítích / Anonymity in P2P Networks

Brunai, Adam January 2014 (has links)
Freedom of speech and the right to privacy are maybe the most important elements of a modern society, yet the rights are often violated. This fact was the main reason for writing this thesis covering P2P network models, anonymity, censorship resistance and their use in real P2P networks and publishing systems. We discuss their effectiveness and suitability for specific purposes, but also the security considerations of their use. The second part of this thesis presents the LSPP publishing protocol, which is an library implementation of an anonymous censorship resistant P2P network. Finally, we analyze the proposed protocol and compare it with existing solutions.
145

Zpracování dat z online diagnostického systému / Data processing from the online diagnostic system

Cirhanová, Iva January 2021 (has links)
This master thesis deals with data processing from an online diagnostic system. The theoretical part of the work is divided into three chapters, the first deals with technical diagnostics as such, there are basic terminology and concepts associated with technical diagnostics, such as diagnostic methods, tools, models and signals. The second part is focused on diagnostic systems and their division. This chapter also provides some examples of online diagnostic monitoring systems from three different companies. The last chapter of the theoretical part is devoted to the description of the possibilities of data collection from diagnostic systems, ie. description of communication buses and protocols. The practical part of this work focuses on creating an application for data collection and visualization.
146

Middleware pro framework Testos / Middleware for Testos Framework

Červinka, Radim January 2021 (has links)
Cílem této práce je vytvořit komunikační sběrnici pro platformu Testos, což umožní nástrojům platformy spolu komunikovat a využívat navzájem svoje služby. V textu jsou prozkoum8na současná řešení a protokoly založené na modelu Publish-Subscribe. Dále také práce specifikuje požadavky na komunikační sběrnici vyhovující potřebám platformy Testos a také navrhuje řešení pro splnění daných požadavků.   V rámci výzkumu byly prozkoumány tři řešení - MQTT, DDS a AMQP. Průzkum každého řešení byl zaměřen na způsob komunikace a hlavní funkční prvky. Jako startovací bod implementace sběrnice byl vybrán protokol MQTT. Tato práce také specifikuje jak tento protokol rozšířit, aby byly splněny požadavky na sběrnici. Mezi stěžejní rozšíření navrhnuté v rámci této práce patří management životního cyklu požadavků rozšiřující způsob doručování zpráv a mechanismus zasílání požadavků standardu MQTT. Protokol byl také rozšířen o možnost shlukování zpráv do BULK paketu za účelem snížení množství potřebných síťových zdrojů. Výsledkem je Testos Bus, který je postavený na upraveném a rozšířeném protokolu MQTT, který zahrunuje implementaci brokeru a klientských knihoven pro Python a C++. Testos Bus naplňuje všechny povinné požadavky platformy, což ověřují automatické testy.
147

Správa a automatizace systému vytápění podniku / Management and Automation of Enterprise Facility Heating System

Hartmann, Jiří January 2021 (has links)
The aim of this work is to create a unified control and supervision system, SCADA, for controlling the heating and cooling of the company. The system is controlled by UniPi PLC units. Node-RED is used as control software. The user interface is created by an extension "dashboard". For communication between elements using the MQTT protocol. The InfluxDB database is used for data storage. The Grafana tool is used to visualize historical data. The majority of the created system consists of open software. The system is universal, expandable and it is possible to connect it with another system. The system can be used or adapted to similar problems of advanced heating control.
148

Implementace komunikačního protokolu CAN 2.0 v jednočipových mikroprocesorech / Implementation of the CAN 2.0 Communication Protocol in single-chip microprocessors

Machálka, Lukáš January 2008 (has links)
This diploma thesis deals with the implementation of the CAN 2.0 communication protocol in single-chip microprocessors. In the first part communication protocols currently used in automotive application and their properties are described, with impact on communication protocol CAN 2.0. The second part is dedicated to the description of communication protocol CAN 2.0 particular features. The principle of data transmission, principle of bus arbitration and also the structure of individual frames, which can occur on it are mentioned. The final part relates with the task to compare FIFO architecture to MailBox architecture. On the basis of measurement the comparison of these architectures in typical applications was performed. Because of setting these results the prototyping board was designed. This board was utilized to design the net conception.
149

Implementace kvality služby do řízení síťového prvku / Implementation of quality of service in the control of a network element

Boháč, Martin January 2008 (has links)
The main task of the Master Thesis is introduction into problems of quality of service in converged networks especially with use of IP protocol version 6. Converged networks are able to transfer different data types - voice, data or multimedia stream. Design of active network unit is realized in Matlab Simulink. Designed model consists of simple network with some computer terminals which are connected with network element - switch. Switch model simulates real traffic of computer terminals, that are sending data to remote users. Packets in switch are sorting by data stream type and QoS. Switch is managed by neuron network. Neuron network reacts to input data and controls switch depending on type of recipient. Switch model can be used in laboratory exercising. Solving this theme needs basic skill in Simulink and theme can be done in one laboratory exercise.
150

Analýza řídících protokolů využívaných v průmyslových aplikacích / Analysis of distributed control protocols for indistrial applications

Horych, Vladimír January 2009 (has links)
This master's thesis deals with distributed control protocols for industrial applications. It explains term distributed control system, control protocol and it is dealing with properties, frame structures and ways of communication within CAN, Modbus, IEC60870-5-101 and DLMS protocols. This thesis includes informations, which are in most cases difficult to find. Second part of the thesis is dedicated to education system. This part is contained by information about protocols and their layers based on ISO/OSI model, pictures of structure of messages, knowledge test and an application based on JavaScript language. This JavaScript application emulates behavior of workstations, which are using communication based on IEC 60870-5-101 protocol. This application can set various conditions for influence of message transfer. These conditions are setting way of message transfer, data availability, filling of workstation’s buffer or intentional damage of message's content. It also contains a large amount of context help, activated after moving mouse cursor over most of application's elements. Even visitor without great knowledge of distributed control systems should understand how this protocol works, thanks to these context help and messages printed in lower part of the application. The conclusion of this work is aimed to positive and negative features and comparison of mentioned control protocols.

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