|
|
Making up missing audio signal sections
Pospíšil, Jiří ; Rášo, Ondřej (referee) ; Mach, Václav (advisor)
The goal of this bachelor’s thesis is to get introduced with methods for reconstruction of missing samples in audio signal using periodicity-based interpolation and AR model based interpolation. Further it’s introducing us with Audio Inpainting method based on sparse representation. In practical part there are programmed three algorithms based on these interpolation methods and described an algorithm which is used in Audio Inpainting. These algorithms are compared with objective methods, SNR measurements depending on gap length and value of input parameter.
|
|
|
Neural networks in cryptography
Borkovec, Tomáš ; Rášo, Ondřej (referee) ; Martinásek, Zdeněk (advisor)
Bachelor's thesis aims to introduce neural networks and their properties, which can be used for creating cryptographic protocols based on neural networks. It proposed concrete use of neural networks in cryptography and creates a teoretical basis for the practical implementation. In practical section is discusses the creation of neural network on which we based cryptographic model. The constructed models are then subjected to testing. At the close of the thesis we discussed the advantages and disadvantages of possible use in real cryptographic modules.
|
|
|
Establishment of database of musical instruments recordings
Lavický, Vojtěch ; Mácha, Tomáš (referee) ; Rášo, Ondřej (advisor)
In this Bachelor thesis you can find created database of musical instruments. Recordings are descripted by it's waveforms and sectrograms. It may serve for example for removing noise from signal. A general data of instruments are descripted here. Human earing and his perception of sound is discuss here. There are also included parameters of sound itself and theory of calculations. Frequency and dynamic range are written to every instrument in database. These are consequently range by its size. As a part of the thesis is program with graphical user interface. The program include all the recordings from database and is open to any other recordings.
|
|
|
Real time signal processing
Nepovím, Pavel ; Rášo, Ondřej (referee) ; Mlýnek, Petr (advisor)
The aim of the master’s thesis is to acquaint the reader with Discrete Fourier Transform DFT and its introduction to spectral analysis descrete time signals. Furthermore it describes efficient computation of the DFT using the algorithm Fast Fourier Transform FFT and effects that appear in the DFT spectral analysis, the effect of the length of the DFT, the effect of the length of the segment of the analysed signal and the leakage. Next is explained the issue of the complex representation of real bandpass signals in the baseband, called the complex envelope of signals. This represenation uses the Hilbert Transform and the analytic signal. The thesis also describes the application library Real Time Toolbox of the software Matlab/Simulink, that uses the data acquition card AD622 allows to connect and process real signals in real time. In Matlab/Simulink with use this facilities is create the laboratory lesson, that simulating the complex represenation of real bandpass signals in real time.
|
|
|
Subjective evaluation of background noise in audio systems
Falešník, Vlastimil ; Mach, Václav (referee) ; Rášo, Ondřej (advisor)
In this bachelor thesis, the effect of additive background noise on audio recordings was researched. This kind of noise often occurs when these recordings are being restored. The most frequent effort is to suppress these unwanted noises. While suppressing the noises, the most problematic part is that it always depends on subjective evaluation of the listener. Practical impacts of these noises were researched throughout two listening tests. Afterwards, it was necessary to choose proper (ordinal) evaluating scale. The listening tests established the subjective assessment of jammed additive noise degree. Finally, the effect of selected parameters on subjective perceived quality was determined.
|
|
| |
|
|
Methods for automated camera focusing
Kičina, Pavol ; Rášo, Ondřej (referee) ; Šmirg, Ondřej (advisor)
This bachelor´s thesis is about methods of focusing with web camera. Edge detection method and Discrete cosine transform method are use in this thesis. In program MatLab I create a program, which take a picture from web camera. With handle focusing this program shows information how much is picture focus. Functional and elementary are subject, which I use to compare. Advantages and disadvantages are in this thesis, with important elements about quality of focus,too.
|
|
|
Real-time spectral analysis in LabVIEW software environment
Vašátko, Karel ; Průša, Zdeněk (referee) ; Rášo, Ondřej (advisor)
This bachelor thesis deals with issues of signal processing and display its spektrum in the environtment LabVIEW. Here is description signal processing theory, description of a block diagram of a spectral analysis and description of the methods for compute power spectral density. In the main part is a description of program developed for real-time spectral analysis. Part contains block diagrams and measurements.
|
|
|
IMS security solutions
Porubský, Tomáš ; Rášo, Ondřej (referee) ; Mácha, Tomáš (advisor)
In the first part of my master's thesis the network architecture of IMS (IP Multimedia Subsystem) is presented. The database of subscribers HSS (Home Subscriber Server) and SLF (Subscription Locator Function), as well as a SIP CSCF servers (Call Session Control Functions) process a SIP signalization and an AS application server performing services, etc. I focus on the registration of subscribers in the IMS network with a list of transmitted messages and description of each interface that is used in this network. The most important interfaces, which I described here, are Gm, Mw, Cx, Dx and Sh. Then I focused on security in IMS problems, which are divided into categories of access security and network security. After that is the implementation of IMS network in an open source Open IMS Core System considered under the Linux operating system. Here is the problem description from the actual system installation, through the configuration of all necessary elements of the network to the communication party itself. The communication analysis in the initial registration process and in subsequent communications is described. Finally I created laboratory exercises with a focus on the Open IMS Core System, where students learn about architecture and principle of networks based on IMS technology operation, with individual elements necessary for the operation of the network and their configuration. Students also test simple captured traffic analysis.
|
|
| |
guest ::
