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Loudspeaker Box for Laboratory Measurements of Loudspeaker Impedance
Nevole, Tomáš ; Káňa, Ladislav (referee) ; Schimmel, Jiří (advisor)
In this thesis there are solved problems of design and construction of a universal modular loudspeaker box, which should serve for laboratory measurements of broadband electro-magnetic loudspeaker’s impedance. These measurements should demonstrate how the electric parameters are changed by changing the acoustic impedance of surrounding into which the speaker transmits. In the first part there is explained necessary theory for solving the task, such as way of sound’s transmission in the environment, variable sorts of speakers and their characteristics. A special focus is given to description of the electro-magnetic speaker’s parameters and construction that was used for the loudspeaker box. Then there are introduced needed mathematical formulas for algebraic design of the loudspeaker box, various types of the loudspeaker boxes (open, closed, vented) and their parameters. In this thesis there is also solved the problem with leaks and settled the matter, if it is better to build one modular box or 2 or 3 separate boxes. Most important characteristics are the impedance characteristics for this thesis but the SPL characteristics are also included. Unfortunately the simulating programs couldn’t generate the hodographs of impedance. After the algebraic calculations, in the thesis there are presented outputs from simulation programs Unibox 408 and WinISD 0.6. The outputs also are compared with the algebraic calculations. In the last part of the thesis there is already described the own construction of the loudspeaker box and presented results from the box’s measuring in the anechoic chamber (in the laboratory of electro-acoustic). The measuring of the modular impedance characteristic was realized on the single speaker and all the boxes. The measuring of the SPL (sound pressure level) characteristic was realized on the boxes only. All these results are compared with the calculations and simulations and the inaccuracies are substantiated in the end. The comparing of the manufacturer’s characteristics with the measured characteristics is also included.
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The open mobile phone platform
Malinčík, Ondrej ; Šteffan, Pavel (referee) ; Macháň, Ladislav (advisor)
The aim of this work is construction of mobile phone which can be build using com- ponents that are widely available. The concept allows control of mobile communication in GSM network on AT commands level. Energy saving is emphasised and alternative power source using solar cell is examined. Manufacturing data and docummentation is available for user.
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Thermal baths Yverdon, five senses in architecture
Křížová, Iveta ; Křikavová, Iva (referee) ; Koleček, Ivan (advisor)
The aim of this work is the solution spa area includes Yverdon les Bains. The existing facility does not meet both their needs, but mainly it is very closed. Park is closed to the public and within his right in the spa area there are several other barriers. Spa Park means to me park, promenade, people moving and elegance. At this point I feel the potential that could reopen the spa park outside world and effortlessly be connected to the outside world, with reference to its historical and thermal value. Therefore, I leave the pit area as much free, with public functions. The spa itself would not be contrary overload the body, but rather a place to stop and peaceful rest. That is why I put myself into a compact mass flowing above the park, which leave the most relaxed movement of people and devote themselves intimacy baths, views of the surroundings and contact with water, the sky opened atrium. Its shape and facade of the building creates a barrier, but rather is permeable and in contact with their surroundings and park.
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Loudspeaker Box for Laboratory Measurements of Loudspeaker Impedance
Nevole, Tomáš ; Káňa, Ladislav (referee) ; Schimmel, Jiří (advisor)
In this thesis there are solved problems of design and construction of a universal modular loudspeaker box, which should serve for laboratory measurements of broadband electro-magnetic loudspeaker’s impedance. These measurements should demonstrate how the electric parameters are changed by changing the acoustic impedance of surrounding into which the speaker transmits. In the first part there is explained necessary theory for solving the task, such as way of sound’s transmission in the environment, variable sorts of speakers and their characteristics. A special focus is given to description of the electro-magnetic speaker’s parameters and construction that was used for the loudspeaker box. Then there are introduced needed mathematical formulas for algebraic design of the loudspeaker box, various types of the loudspeaker boxes (open, closed, vented) and their parameters. In this thesis there is also solved the problem with leaks and settled the matter, if it is better to build one modular box or 2 or 3 separate boxes. Most important characteristics are the impedance characteristics for this thesis but the SPL characteristics are also included. Unfortunately the simulating programs couldn’t generate the hodographs of impedance. After the algebraic calculations, in the thesis there are presented outputs from simulation programs Unibox 408 and WinISD 0.6. The outputs also are compared with the algebraic calculations. In the last part of the thesis there is already described the own construction of the loudspeaker box and presented results from the box’s measuring in the anechoic chamber (in the laboratory of electro-acoustic). The measuring of the modular impedance characteristic was realized on the single speaker and all the boxes. The measuring of the SPL (sound pressure level) characteristic was realized on the boxes only. All these results are compared with the calculations and simulations and the inaccuracies are substantiated in the end. The comparing of the manufacturer’s characteristics with the measured characteristics is also included.
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The open mobile phone platform
Malinčík, Ondrej ; Šteffan, Pavel (referee) ; Macháň, Ladislav (advisor)
The aim of this work is construction of mobile phone which can be build using com- ponents that are widely available. The concept allows control of mobile communication in GSM network on AT commands level. Energy saving is emphasised and alternative power source using solar cell is examined. Manufacturing data and docummentation is available for user.
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|
Thermal baths Yverdon, five senses in architecture
Křížová, Iveta ; Křikavová, Iva (referee) ; Koleček, Ivan (advisor)
The aim of this work is the solution spa area includes Yverdon les Bains. The existing facility does not meet both their needs, but mainly it is very closed. Park is closed to the public and within his right in the spa area there are several other barriers. Spa Park means to me park, promenade, people moving and elegance. At this point I feel the potential that could reopen the spa park outside world and effortlessly be connected to the outside world, with reference to its historical and thermal value. Therefore, I leave the pit area as much free, with public functions. The spa itself would not be contrary overload the body, but rather a place to stop and peaceful rest. That is why I put myself into a compact mass flowing above the park, which leave the most relaxed movement of people and devote themselves intimacy baths, views of the surroundings and contact with water, the sky opened atrium. Its shape and facade of the building creates a barrier, but rather is permeable and in contact with their surroundings and park.
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Open Mobile Phone Platform
Malinčík, O.
The market provides a wide variety of GSM mobile phones, however, a platform which offers free hardware access is not known. The open mobile phone platform fills this gap and it allows user to approach it on electronic component level, what is useful for educational purposes. The paper describes the platform on the block diagram level with brief overview of used components.
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Analysis of open format videocodecs
Svoboda, Jaroslav ; Truhlář, Filip (advisor) ; Mezuláník, Radek (referee)
Hypothesis of this thesis states that even though open format codecs are available for free, they are equal alternative to the patented ones. This was verified by set of objective tests. Quality of videos was measured by PSNR and SSIM methods firstly on HD 8-bit sequences with various framerate encoded by Theora, VP8, VP9, H.264 and H.265. Afterwards were codecs tested on 4K 10-bit sequence encoded by coding standards H.264, H.265 and VP9 codec to see how they will perform in future usage in UHD content distribution. Last test shows computational demands and quality in fast encoding mode. Thesis also includes overview of each codec support by ICT devices, which is not as wide as H.264's but is raising.
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Open Source ERP systems
Šťastný, Kryštof ; Pour, Jan (advisor) ; Basl, Josef (referee)
The work describes the situation about Open Source ERP systems. Initially it is introducing expressions like Open Source and ERP system. Then it describes the structure of costs and expected effects. Next it analyzes the methodology and implementation processes of Open Source ERP system in the small and medium-sized enterprise. It reflects the relationship between supplier and customer and points out the importance of planning and evaluation of the achieved effects. The last part is focused on the classification of selected leading Open Source ERP systems. It deals with the analysis, definition of the key features and creating the unified overview. To conclude using a detailed weighting evaluation of individual criteria it compares selected leading Open Source ERP Systems with regard to the implementation of risk.
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