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Progress of welding in shipbuilding
Urban, Václav ; Kubíček, Jaroslav (referee) ; Kovář, Petr (advisor)
This work deals with the methods of welding in shipbuilding, summarises the basic techniques used for welding of the SAW, MAG, MIG, TIG, laser, Laser-Hybrid. It describes the properties of welded material. Especially the materials HY80 and HY100. It follows from the filler materials. In particular materials Spoolarc 95 and 120. Particular emphasis is placed on the method of Laser-Hybrid, its properties and use in shipbuilding. Finally, describes the method of welding aluminium using FSW, preparation of welded surfaces and producting of sandwich panels.
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Converged solution of speech services
Mácha, Tomáš ; Kovář, Petr (referee) ; Novotný, Vít (advisor)
Development in VoIP technology is connected with the rapid growth of quality and data rate of the Internet connection. The application of the VoIP technology has become one of the key areas in telecommunication and networking. The main task of this thesis was to explore the questions of IP telephony and voice transmission over data networks according to H.323, SIP and Cisco architectures. Next focus was on designing and implementing experimental workplaces of mentioned architectures and their converged solutions. The purpose of the first chapter is to introduce the theory background of architectures required for implementation of real-time services in data networks and their comparison. The key objectives of the second and third part are to design and implement experimental workplaces containing signaling and proxy servers and hardware or software IP phones of several architectures. Illustration examples of different network topologies are included to demonstrate designed and realized VoIP solutions. Several tests of established communication are done using a packet analyzer. These tests examine duplex data transmission over IP. This article also contains two laboratory exercises designed according to gained practical experiences. The laboratory exercises provide an overview of theory and clearly indicate the possibilities of IP telephony.
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Qualification of welding procedure - WPQR
Houra, Milan ; Kubíček, Jaroslav (referee) ; Kovář, Petr (advisor)
The project developed within the bachelor's degree field of B-STG Engineering technology is focused on developing protocols for a preliminary welding procedure specification for a given drawing pWPS weldments. Subsequent to preliminary approval of these protocols are implemented protocol for qualification of welding procedures WPQR. This WPQR protocol is drawn up for a similar award has developed pWPS protocols. The most important parts of the protocol WPQR are destructive and nondestructive tests, which are discussed from both theoretical and practical in the field. At the end of the WPS is the resulting log with a direct link to WPQR protocol is implemented and appreciation of the control tests.
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SIP/H.323 gateway with Asterisk PBX
Smékal, Lukáš ; Herman, Ivo (referee) ; Kovář, Petr (advisor)
This Bachelor’s thesis is engaged in problems of the internet telephony and its usage in today´s world, which offers many techniques how communicate among people. The internet telephony gives telephoning other format and shows new possibilities of IP protocol´s usage. The thesis is focused on the most used protocol corveying functions of VoIP technology, it is the standard H.323 and also the SIP protokol, which even if provides the same functions as H.323 is based on the different principle and because of its easy structure, it prepares good conditions for rise of new applications and services in internet telephony. In this thesis the Open Source private branch exchange Asterisk is also discussed. Asterisk, not only thanks to the usage of Voice over IP provides against the standard analogue private branch exchange many advantages and thanks to its modularity and expansibility also offers much more possibilities of configuration. The Session Initiation Protocol (SIP) is the basic protocol, with which Asterisk works. The standard H.323 is not implemented in the basic installation of Asterisk, therefore it is necessary to do its suitable installation and congiruation, in order to expand exchange´s functions for work with this standard and also to be able to realize translation between the protocol SIP and the standard H.323. The results, which I accomplished, are presented in the chapters „Dosažené výsledky“ and in the conclusion of the bachelor’s thesis.
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Possibilities of Error Controls in Frequency hopping Stations
Pust, Radim ; Kovář, Pavel (referee) ; Wieser,, Vladimír (referee) ; Burda, Karel (advisor)
The doctoral thesis deals with design of coding for frequency hopping stations in band with intensive jamming. In digital modulations erroneous determination of the modulation state occurs due to jam at the receiver side. The result is erroneously transferred symbols of the message. Errors created during the transmission can be eliminated by using error control systems. It is also possible to prevent these errors by using algorithms (techniques) of frequency hopping which select the appropriate channel. Appropriate communication channel is a channel with a lower probability of erroneous symbol in the message. The main contribution of this thesis is to design a new frequency hopping technique with collision avoidance (FH/CA). The station with FH/CA technique measures signal levels in the considered several channels before every jump. Based on the measurements the most appropriate channel with the lowest value of measured signal level is selected. Therefore, it is more probable that a jump to an unoccupied channel with a transmission will occur. Using a mathematical model, the performance of the newly proposed FH/CA technique is compared with the currently used techniques FH and AFH. Comparison criteria are the probability of a collision between an FH/CA communication system and a static (device transmitting continuously at a fixed frequency) or dynamic jammer (i.e. other FH or AFH systems). By comparing the values of the probability of jammed transmission, indisputable theoretical advantages of the new FH/CA technique were found, compared to the currently used FH and AFH techniques. The FH/CA technique always has better or equal results compared with the FH technique in the case of interference by static and dynamic jammers. The FH/CA technique in a band with static and dynamic jammers usually has better results than the AFH technique. A significant contribution of the FH/CA technique can be seen in the case of dynamic jammers. On the other hand, in the case of static jammers the FH/CA technique is in certain situations worse than the AFH technique. The accuracy of the mathematical models were successfully verified on a simulation model that was created as a part of this thesis in the MATLAB environment. Based on the obtained data from the model there was designed coding for frequency hopping stations with the new technique of frequency hopping FH/CA which is designed for small-volume data transfer in a band with intensive jamming.
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Modern treatments by powder paints
Blažek, Jaroslav ; Kovář, Petr (referee) ; Kubíček, Jaroslav (advisor)
The bachelor thesis was written in the subject B 2341 within the bachelor studies. It deals with the analysis of finishing treatment with the powder plastics. The growth of innovations has recently been registered in this field. The thesis contains analysis of particular surface pre-treatment methods suitable for powder coating. Next, there is the powder plastics analysis and their application methods. The setting process description and the description of several color systems used today are also part of the work.
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Analysis of adhesives in general engineering
Trhoň, Vojtěch ; Kovář, Petr (referee) ; Kubíček, Jaroslav (advisor)
This bachelor thesis is concerned with analysis of adhesives in general engineering and it is focusing on the partition of adhesives according to curring and usability. Positive and negative mechanical stress of glued joints are characterised here. The technologic process of gluding side panels of tram is elaborated in the end of this bachelor thesis.
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SMS Application for JavaME Platform
Růčka, Lukáš ; Burget, Radim (referee) ; Kovář, Petr (advisor)
The aim of this diploma thesis is to study the potential of Java ME platform for receiving and sending of SMS and to utilize obtained information subsequently in implementation of an application for this platform. The first part of the diploma thesis aims at explaining general terms of the Java language and its basic features. The next part deals with specific properties of the Java ME platform and properties of devices that support this platform. A design of the Java ME application based on theoretical knowledge is created then. This application has to be able to receive, process, store and send SMS and communicate with the server application based on the Java SE platform. The created Java ME application serves as an automated SMS voting server, which can be used in mobile devices that support the Java ME platform and can be remote-controlled via Internet from the Java SE platform application. The final chapter presents the results and conclusions of testing of the created application on real mobile devices.
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Detection Algorithms of Radar Targets
Štukovská, Petra ; Kovář, Pavel (referee) ; Veselý,, Jiří (referee) ; Kubíček, Michal (advisor)
This thesis focuses on detection algorithms of radar targets, namely on group of techniques for removing of disturbing reflections from static objects - clutter and for suppression of distortion products caused by the phase noise of the transmitter and receiver. Methods for distortion suppression in received signal are designed for implementation in the developed active multistatic radar, which operates in the code division multiplex of several transmitters on single frequency. The aim of the doctoral thesis is to design, implement in tool for technical computing MATLAB and analyze the effectiveness and computational complexity of these techniques on simulated and real data.
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