|
|
Wavelet analysis and enhancement of MR tomography and ultrasound images
Matoušek, Luděk ; Bartušek, Karel (referee) ; Smékal, Zdeněk (advisor)
Tomographic MR (Magnetic Resonance) and sonographic biosignal processing are important non-invasive diagnostic methods used in a medicine. A noise added into processed data by an amplifier of tomograph receiving part and by circuits of sonograph is resulting in a body organ diagnosis degradation. Image data are stored in a standardized DICOM medical file format. Methods using wavelet analysis for noise suppression in image data have been designed and their comparation with classical methods has been made in this work. The MATLAB was utilized for data processing and data rewriting back to the DICOM format.
|
|
|
Analysis of Heart Rate Variability
Škrtel, Karol ; Kolářová, Jana (referee) ; Provazník, Ivo (advisor)
The project describes the methods useful for observe changes of heart rate in ECG signal. Heart rate variability become (HRV) the conventionally accepted term to describe variations of NN intervals between consecutive heart beats and generally it is function of instantaneous heart rate or NN interval on time. HRV may be evaluated by time domain or frequency domain measures. In Matlab was developed algorithm, realized like function, which counts HRV parameters from ECG signal series. Analysis in time domain adverts to high correlation between statistic and geometric parameters and similarly with signal HRV. Results of frequency domain analysis shows similarity of power spectral density, which was calculated by two different ways (from interpolated and no interpolated signal HRV). Functionality of developed algorithm was verified on each signal. Project results have signification in progress of analysis ECG signal methods with a view to observe pathological changes in heart rate.
|
|
|
FIELD II - modelling of the ultrasound field
Štrbík, Jiří ; Čížek, Martin (referee) ; Kolář, Radim (advisor)
This bachelor thesis presents the way of modelling the ultrasonic field with FIELD II package implemented in MATLAB 7 enterprise. The first part of the thesis provides the theoretical information about supersound. It describes the main properties of supersound and the processes that composse ultrasonic pulse. The principle and the significance of Doppler effect is also cleared up in this section. Finally, this part deals with ultrasonic probes, with their subdivision and their main parameters. In the second part of the thesis the FIELD II package is described. This part provides the information on the installation of the package and about the usage of the functions for modelling the ultrasonic field. This part also shows examples that illustrate the utilization of the package for teaching purposes.
|
|
|
Sensitivity analysis in distributed-parameter systems
Kapusta, Ján ; Dostál, Tomáš (referee) ; Brančík, Lubomír (advisor)
The aim of this bachelor’s thesis was to familiarize with calculation of modified nodal analysis and its application in distributed-parameter systems. Realize evaluation of sensitivities with respect to a primary parameters R0,L0,C0,G0 and length l of transmission line. Then apply this technique on example in Matlab language using graphical user interface GUIDE. Selected technique is accelerated method based on efficient computation of matrix exponential function. The results are sensitivities of circuit values with respect to a primary parameters R0,L0,C0,G0 and length l of transmission line.
|
|
|
Electromyography, measurement of muscle electric activity
Kořínek, Peter ; Provazník, Ivo (referee) ; Kolářová, Jana (advisor)
The task of this thesis was to become acquainted with the issue of measuring of muscle electric activity.In the theoretical part we became familiar with the computer measuringsystem BIOPAC and its options to measure monitored magnitudes. This continue with practical part, in which we watch the problematic according to a theory in a group of people. We learned data with BIOPAC according to protocol of the result of physicaleffort influence on EMG. In the end the results were statistically analysed. The data as a product offallowing research were verified by hypothesis. In thelast step, the data are presented in graphical user interface development environment. After loading of the EMG of measured person, the process are displayed-without, with and after the power with onus. It is possible to choose from different analyses.
|
|
|
Video compression based on wavelet transform
Kintl, Vojtěch ; Číka, Petr (referee) ; Malý, Jan (advisor)
This diploma thesis focuses on current possibilities concerning the employment of wavelet transformation for video signal compression. One part of the work is devoted to the necessary execution of this task in practise. This deals with video signal and its features description, wavelet transformation and compression methods. The second part concentrates on description of selected compression method. It is the SPIHT (Set Partitioning In Hierarchical Trees) algorithm which is intended for compression of static image data. The algorithm is modified for usage with video signal compression which is specific for its time redundancy. The algorithm is called 3D SPIHT as it works in the spatial and time domain. The algorithm is implemented in the MATLAB programming environment which provides a sophisticated support for wavelet transformation (Wavelet Toolbox). To provide a simple and intuitive encoder control there has been developed an application delivering graphical user interface (GUI). On displayed image previews and measured graphs the user can change encoder parameters and monitor performed changes. There are four image test-sequential modes containing various scenes with different features. The final part of the work is focused on testing of the proposed encoding scheme, various image test-sequential modes and encoder settings. Measured values are graphically displayed and analyzed.
|
|
|
Watermarking of digital data
Kupka, Jan ; Přinosil, Jiří (referee) ; Číka, Petr (advisor)
The main aim of this project is to implement two different types of the watermarking algorithm in frequency (transforamtion) domain. Because of the huge amount of the watermarking algorithms is this thesis dedicated to the watermarking methods in the frequency domain. These methods use kind of transformation implemented on the original data, the second step is modification of transformation coeficients. This project is dedicated to the methods which use discrete wavelet transformation. Nowdays the most popular transformation, which meets the best efforts. The aim of every method is to embeed the watermark into the original data so precisly, that none observer can recognize any change between the original and watermarked data. On the contrary, watermarked picture should be as resistant to the attacks as possible. By the term of attack, we understand all the ways, that disable watermark extraction. The watermark method robustness will be tested with the use of Checkmark program.
|
|
|
Processing of electromagnetic and acoustic emission signals during mechanical stressing of solids
Šopík, Martin ; Holcman, Vladimír (referee) ; Koktavý, Pavel (advisor)
Electromagnetic emission and acoustic emission are physical phenomena evoked in non-conductive material by the sudden release of energy that generate rising cracks in material structure. The significant is a fact that these emission signals are detected already in stadium of materials loading whereof can be used e.g. at non-destructive diagnostics of building materials and constructions. In the appropriate manner processing of the emitted signals then make possible to obtain valuable informations for study physical properties of cracks. Master’s thesis describes methods designed for important signal data ascertainment in time, frequency even time-frequency domain. It can be e.g. start time, maximum value, dominant frequency in spectrum etc. All these methods are implemented into main program. Next load is formularization of source signal transformation which is given by used measuring circuit. Analytical method is chosen for solving. It means finding out reserve electrical circuit with constant element values. Resultant circuit approaches original circuit with less square error than existing way. The signal transformation is described by differential equation of second order with constant coefficients. MATLAB software is used for all computations and projections.
|
|
|
Watermarking of static images
Bambuch, Petr ; Burda, Karel (referee) ; Číka, Petr (advisor)
The thesis deals with the security of static images. The main aim is to embed the watermark into the original data so effectively, to avoid removal of the watermark with the use of simple and fast attacks methods. With developing of the watermarking techniques the technique of attacks are improved and developed also. The main aim of the attacks is to remove and devalue the hidden watermark in the image. The goal of the thesis is to check current techniques of static image watermarking and implement two methods of watermarking, which are to be tested for robustness against attacks.
|
|
|
Jiří Wolf Measurement of the properties of ultrasound system
Wolf, Jiří ; Čížek, Martin (referee) ; Kolář, Radim (advisor)
This diploma thesis deals with the displaying process evaluation from the resolution capabilities of the ultra-sonic probe point of view. As a part of the thesis a method for measuring the response from point spread function (PSF) and method for measuring the response from linear spread function LSF were designed. Collected data were processed in the Matlab environment. Basic evaluation parameters of the space resolution capabilities were set and used – axial, lateral and traversal resolution.
|
guest ::
