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The AmBe Laboratory Neutron Source Field Determination Using Experimental Stend
Jelínek, Martin ; Šťastný, Ondřej (referee) ; Katovský, Karel (advisor)
This master’s thesis provides a comprehensive overview of the conventional neutron sources from the perspective of reactions which lead to the production of neutrons, advantages, disadvantages, properties and their possible utilization. In the relation to the assembly of the laboratory neutron source and the unique experimental stand “Candle” basic methods of the neutron field analysis are outlined and two of them, the neutron activation analysis and the calculation using the MCNP software code are discussed in depth to apply and compare these methods. The experimental part deals with the realization of neutron activation analysis from its design itself, through gamma spectrometry to the cadmium ratio calculation. In compliance with the measurements, a calculation with MCNP code was run and both methods were evaluated and compared. The computation is complemented with the analysis of radiation situation on the borders of the supervised area, which is compared to the legal limit.
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Suggestion of a Company Communication Mix
Sombergová, Markéta ; Jelínek, Martin (referee) ; Kaňovská, Lucie (advisor)
The diploma thesis focuses on problems associated with the suggestion of the communication mix of the Fitness centre „Kameňák“. It includes evaluation of the current state of company´s communication mix and revelation of problems in this field. Afterwards the thesis contains suggestions for improvement of this state. The diploma thesis is divided into three parts. The first part contains theoretical knowledge of the subject, the second part is focused on analysis of the company´s current state and the main content of the third part is suggestion of such a communication mix that can help the company present better its services and brings more customers.
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Security of wireless computer networks
Jelínek, Martin ; Pelka, Tomáš (referee) ; Doležel, Radek (advisor)
The master's thesis deals with the issue of Wireless Local Area Network (WLAN) from the viewpoint of the security and functional principle of security mechanisms. The transition to the issue concerning the security is accompanied by the methods of wireless data transmission operating on the level of physical layer (FHSS, DSSS, OFDM, MIMO), which is followed by the summary of individual 802.11 standards. The next part deals with the issue of shared transmission medium (CSMA/CA), influence of interference and correcting mechanisms (RTS/CTS). Within the security, the principles of the authentication along with the commonly used methods of security (WEP, WPA, WPA2) are described in detail. The first part concerning security deals with the security in the form of the WEP protocol, which is considered insufficient nowadays and points out the imperfect implementation and the consequent risks. The following part describes the security in the form of WPA which eliminates the implementation weaknesses of the previous WEP security protocol. The description of commonly used mechanisms of authentication (PSK, 802.1x), required temporary key management (PTK, GTK), data integrity (MIC) and encryption which uses TKIP protocol are also included. The last part, possible WLAN security, is aimed at the full support of 802.11i standard, which is called WPA2 (sometimes RSN). That part describes the basic encryption security element CCMP, which is based on the AES block cipher modes. The practical part of the thesis deals with the security verification of current wireless networks. In the process of verification the accessible HW means and programming tools of Open Source Software (OSS) are used. By means of verification it has been pointed out that there are possible security risks resulting from the security method which has been used. Also several recommendations how to reduce the security risks of the used method to minimum are mentioned.
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Use of Head-mounted displays in risk management for machine tools
Jelínek, Martin ; Kotek, Luboš (referee) ; Tůma, Zdeněk (advisor)
This diploma thesis deals with the design and technical possibilities of VR headsets and their application in mechanical engineering, specifically in the field of risk management in machine tools, using experience from other areas and history. The practical part of the thesis comprises a risk analysis carried out on a single selected machine (vertical machining center) by means of checklists and virtual technologies. The risk analysis techniques used are subsequently compared and evaluated. The results are then assessed and a proposal for the use of virtual reality in practice is put forward.
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Investigation of nanomaterials for their nuclear power and research utilization
Jelínek, Martin ; ČEZ,, Jiří Skalička, (referee) ; Katovský, Karel (advisor)
This bachelor thesis provides a comprehensive overview of the properties of various nanomaterials and summarizes the latest findings and knowledge of advanced applications in all sectors of nuclear power engineering from construction materials through nuclear fuel, fuel cladding, neutron moderator and coolant to the advanced methods for detection of ionizing radiation ad its direct utilization for electricity production. A significant space is devoted to the applications in safety systems of nuclear power plants. The experimental part of the thesis deals with the possibility of using carbon nanofibers as an additive to the coolant in VVER reactor type in order to improve the thermal properties of the coolant. So far a very little examined issues of neutron balance changes due to interaction with nanoparticles was experimentally verified on the paraffin wax mixture of two different concentrations. The comparison with the reference sample of pure paraffin was also made.
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Safety of milling machines
Jelínek, Martin ; Blecha, Radim (referee) ; Blecha, Petr (advisor)
This bachelor thesis sort out a review of legislative requirements and standards according to the European Parliament and Council in the field of machine tools. It also deals with the explanation and inclusion of harmonized standards into the czech legal system. The safety requirements and the check lists are developed for the selected universal milling machine.
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Design of mountain-bike crossbar and its FEM analysis
Jelínek, Martin ; Maňas, Pavel (referee) ; Vrbka, Martin (advisor)
The aim of this diploma thesis is the part of evolution of the new bicycle frame for mountain biking, category enduro. The first part of this thesis is focused on creating dimensional modified model of the bike frame in CAD system SolidWorks. Subsequently this frame will be detailed by FEM analysis in software ANSYS Workbench and determine boundary conditions for this analysis. The final part is about visualization of the new bike frame.
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Systems with frequency hopping
Jelínek, Martin ; Říha, Kamil (referee) ; Pust, Radim (advisor)
This bachelor´s thesis deals the systems, which use the Frequency Hopping (FH). The brief history of frequency hopping and its development together with Adaptive Frequency Hopping technology (AFH) is introduced. The general function principle of AFH, which differs AFH from FH, is described. Advantages and disadvantages of frequency hopping and its division into fast (FFH) and slow (SFH) are described next. Some of military communication systems (e.g. SINCGARS, Eritac, MRR, Panther V-EDR and next) as well as some of commercial systems (e.g. worldwide-spread Bluetooth system) are introduced. Mentioned systems use digital modulations, three of basic digital modulations are demonstrated (ASK - Amplitude Shift Keying, FSK - Frequency Shift Keying and PSK - Phase Shift Keying). Basic types of used spectrum spreading (FHSS, DSSS, OFDM) are mentioned next. The FHSS type of spectrum spreading is described in more detail, because the spectrum spreading is done by frequency hopping. Particular systems contain error control of radio transmission of information, which is realized by FEC (Forward Error Correction) and ARQ (Automatic Repeat Query) techniques. Practical part of the bachelor´s thesis demonstrates, with usage of Matlab programme, adaptive frequency hopping function (AFH) during communication of Master-Slave devices, where more systems are active. This causes the interference of the communication. This interference is caused by static and dynamic jammers, that work in the same band as the Master-Slave devices.
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Czechoslovak Tourism in Socialist Yugoslavia. Institutions, Imaginations and Reality.
Jelínek, Martin ; Čechurová, Jana (advisor) ; Rychlík, Jan (referee)
International tourism has become a common part of human life. This phenomenon, originating in the modernization of society in the 19th century, has undergone a complex and long development. From its initial stages, when it was reserved for high society, through the understanding of its economic potential for the modern state and economy, to the final massification of international tourism in the second half of the 20th century. In a bipolar world, the specifics of the development of international tourism are shown with respect to which side of the Iron Curtain this tourism is developing on. A special example is if the development takes place somewhere on the border of both blocks. Czechoslovak tourism heading to Yugoslavia is a good example of blending the Eastern approach to traveling abroad with a specific model of the Yugoslav perspective on the phenomenon of tourism. Czech and Slovak tourists have been regular guests since the 19th century, heading precisely to the countries that made up the Yugoslav state. The presented work deals with how the institutionalization of Czechoslovak tourism in socialist Yugoslavia developed and was anchored, i.e. which institutions and in what way they ensured tourism, how and with which institutions on the Yugoslav side they were forced to cooperate and how this...
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