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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
391

Rozměřování záznamů EKG s využitím kombinování metod / Delineation of ECG signals using methods combining

Zahradník, Radek January 2014 (has links)
The aim of this work is to study and describe the principles and method of delineation of ECG signals. Learn and describe about method of cluster analysis. In this work was created and described three different methods of delineations of ECG signals. Created algorithms were tested on complete CSE database. With cluster analysis were combine created methods. The obtained results from realized methods and combined method were compared with others known methods. At the end of this work is evaluate efficiency of detection of combined method.
392

Vlnkový wienerovský filtr EKG signálů / Wavelet Wiener filter of ECG signals

Janů, Joshua January 2014 (has links)
The thesis focuses on the use of wavelet wiener filtration to remove muscular interference from ECG signals. As part of it, a filter has been implemented in the MATLAB programming environment. The main part of the thesis deals with the optimization of numerical parameters of the proposed filter. The results of the filtration are compared with the results reported by other authors.
393

Detekce P vlny v EKG signálech / P wave detection in ECG signals

Bajgar, Jiří January 2015 (has links)
The aim of this diploma thesis is to introduce methods of detection of the QRS complex and the subsequent detection of P waves. The intention is to create a program by specified method in the software Matlab which will be able to implement this method. The thesis describes the basic and important methods of detection and subsequent algorithm to detect P waves. Solution of the algorithm is tested on real data. It also describes the automatic signal evaluation and the results of this automatic function.
394

Rozměření experimentálních záznamů EKG / Delineation of experimental ECG records

Bucsuházy, Kateřina January 2015 (has links)
This master thesis deals with QRS complex detection and ECG delineation. The theoretical part of this work describes wavelet transform, some of QRS detection approaches and some of ECG delineation approaches. For algorithm realization in Matlab is used redundant dyadic discrete wavelet transform. Algorithm is designed for experimental electrocardiograms of isolated rabbit hearts and it is evaluated through manually determined references.
395

Automatické rozměření signálů EKG / Automatic delineation of ECG signals

Vítek, Martin January 2011 (has links)
This dissertation deals with QRS complex detection and ECG delineation. The theoretical part of the work describes basics of electrocardiography, QRS detection approaches, ECG delineation approaches, the standard CSE database and the wavelet transform theory. The practical part of the work describes designed methods of QRS complex detection and ECG delineation. The designed methods are based on a continuous wavelet transform, appropriate scales, appropriate mother wavelet, cluster analysis and leads transformation. The introduced algorithms were evaluated on the standard CSE database. The obtained results are better, than directly comparable results of other methods and accomplished given database criteria. The robustness of designed algorithms was successfully tested on CSE database signals modified by compression and filtering. The proposed ECG delineation algorithm was successfully used as a tool for evaluation of diagnostic distortion of ECG signals modified by compression.
396

Segmentovaná diskrétní waveletová transformace / Segmentwise Discrete Wavelet Transform

Průša, Zdeněk January 2012 (has links)
Dizertační práce se zabývá algoritmy SegDWT pro segmentový výpočet Diskrétní Waveletové Transformace – DWT jedno i vícedimenzionálních dat. Segmentovým výpočtem se rozumí způsob výpočtu waveletové analýzy a syntézy po nezávislých segmentech (blocích) s určitým překryvem tak, že nevznikají blokové artefakty. Analyzující část algoritmu pracuje na principu odstranění přesahu a produkuje vždy část waveletových koeficientů z waveletové transformace celého signálu, které mohou být následně libovolně zpracovány a podrobeny zpětné transformaci. Rekonstruované segmenty jsou pak skládány podle principu přičtení přesahu. Algoritmus SegDWT, ze kterého tato práce vychází, není v současné podobně přímo použitelný pro vícerozměrné signály. Tato práce obsahuje několik jeho modifikací a následné zobecnění pro vícerozměrné signály pomocí principu separability. Kromě toho je v práci představen algoritmus SegLWT, který myšlenku SegDWT přenáší na výpočet waveletové transformace pomocí nekauzálních struktur filtrů typu lifting.
397

Vlnková filtrace elektrokardiogramů / Wavelet Based Filtering of Electrocardiograms

Smital, Lukáš January 2013 (has links)
This dissertation deals with possibilities of using wavelet transforms for elimination of broadband muscle noise in ECG signals. In this work, the characteristics of ECG signals and particularly the most frequently occurring type of interference are discussed firstly. The theory of wavelet transforms is also introduced and followed by design of the simple wavelet filter and the more sophisticated version with wiener filtering of wavelet coefficients. Next part is devoted to the design of our filter, which is based on wavelet wiener filtering and is complemented by algorithms that ensure full adaptability of its parameters when the properties of the input signal are changing. Suitable parameters of the proposed system are searched automatically and the algorithm is tested on the complete standard electrocardiograms database CSE, where it achieves significantly better results than other published methods.
398

Využití vlnkové transformace při zpracování obrazu / Wavelet Transform in Image Processing

Dostál, Martin January 2015 (has links)
The wavelet transform has been used for several decades and it is still an object of research - especially its recent modifications which are using the so-called second generation wavelets. It has several advantages over other integral transformations. The most important of them are the ability to localize both in time and frequency and an ability to decorrelate some real non-stationary signals such as images. For this reasons, the wavelet transform became an often used tool in many image processing tasks, for example in image compression, edge detection or contrast enhancement. In this thesis, the wavelet transform is explained, including the theoretical foundation and implementation for use with two-dimensional discrete signals. Some of the applications of the wavelet transform are presented and described. The wavelet transform showed to be suitable tool for edge detection, noise reduction, contrast enhancement and HDR compression.
399

Komprese obrazu pomocí vlnkové transformace / Image Compression Using the Wavelet Transform

Kaše, David January 2015 (has links)
This thesis deals with image compression using wavelet, contourlet and shearlet transformation. It starts with quick look at image compression problem a quality measurement. Next are presented basic concepts of wavelets, multiresolution analysis and scaling function and detailed look at each transform. Representatives of algorithms for coeficients coding are EZW, SPIHT and marginally EBCOT. In second part is described design and implementation of constructed library. Last part compare result of transforms with format JPEG 2000. Comparison resulted in determining type of image in which implemented contourlet and shearlet transform were more effective than wavelet. Format JPEG 2000 was not exceeded.
400

Detekce síťových anomálií / Network Anomaly Detection

Pšorn, Daniel January 2012 (has links)
This master thesis deals with detecting anomalies methods in network traffic. First of all this thesis analyzes the basic concepts of anomaly detection and already using technology. Next, there are also described in more detail three methods for anomalies search and some types of anomalies. In the second part of this thesis there is described implementation of all three methods and there are presented the results of experimentation using real data.

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