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Mobile internet principles
Jehličková, Lenka ; Fencl, Josef (referee) ; Hanus, Stanislav (advisor)
Thesis concerns with mobile communications theory with focus on data transfer. In the introduction the history, the origin and individual mobile systems generations are described. It is followed by detailed description of second, third and fourth generation mobile systems. Frequency band allocation, signal processing, the system architecture itself, security management and basic features are also discussed. The GSM system is described together with individual data transmission types based on circuit switching – CSD and HSCSD and packet switching – GPRS and EDGE. For UMTS, FDD and TDD modes are listed as well as changes in individual releases, corresponding technologies and provided services. Next, there is the description of LTE and WiMAX systems, together with their improvements whose are part of the fourth generation of mobile systems. Last of the described systems is the still work in progress HAPS, also known as the system of stratospheric platforms. In the end important parameters are summarized and systems are compared with each other.
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Relaxation times in the polymer gel electrolytes by magnetic resonance methods
Jehličková, Lenka ; Kadlec, Radim (referee) ; Kubásek, Radek (advisor)
The purpose of this Bachelor’s thesis is measuring of gelly structure relaxation using magnetic resonance imaging. The first part closely describes the theory needed for upcoming measuring. There is explained basic physical principle of NMR and terms such as precession, Larmor frequency and RF pulses are established. The measuring instrument is also schematically introduced, as are its main parts and division in aspect of magnetic fields. The most important part is explanation and understanding of relaxation processes that happen during NMR. Individual sequences used for measuring of relaxation processes are demonstrated by the spin echo method, which is the basic building block of all successive methods. The second part is processing of results. Measuring of fall and spectre of given gelly samples is expressed as a function of time T2 on the sample solidification time.
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Relaxation times in the polymer gel electrolytes by magnetic resonance methods
Jehličková, Lenka ; Kadlec, Radim (referee) ; Kubásek, Radek (advisor)
The purpose of this Bachelor’s thesis is measuring of gelly structure relaxation using magnetic resonance imaging. The first part closely describes the theory needed for upcoming measuring. There is explained basic physical principle of NMR and terms such as precession, Larmor frequency and RF pulses are established. The measuring instrument is also schematically introduced, as are its main parts and division in aspect of magnetic fields. The most important part is explanation and understanding of relaxation processes that happen during NMR. Individual sequences used for measuring of relaxation processes are demonstrated by the spin echo method, which is the basic building block of all successive methods. The second part is processing of results. Measuring of fall and spectre of given gelly samples is expressed as a function of time T2 on the sample solidification time.
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|
|
Mobile internet principles
Jehličková, Lenka ; Fencl, Josef (referee) ; Hanus, Stanislav (advisor)
Thesis concerns with mobile communications theory with focus on data transfer. In the introduction the history, the origin and individual mobile systems generations are described. It is followed by detailed description of second, third and fourth generation mobile systems. Frequency band allocation, signal processing, the system architecture itself, security management and basic features are also discussed. The GSM system is described together with individual data transmission types based on circuit switching – CSD and HSCSD and packet switching – GPRS and EDGE. For UMTS, FDD and TDD modes are listed as well as changes in individual releases, corresponding technologies and provided services. Next, there is the description of LTE and WiMAX systems, together with their improvements whose are part of the fourth generation of mobile systems. Last of the described systems is the still work in progress HAPS, also known as the system of stratospheric platforms. In the end important parameters are summarized and systems are compared with each other.
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