National Repository of Grey Literature 28 records found  beginprevious19 - 28  jump to record: Search took 0.00 seconds. 
Analysis of long-term electrocardiograms
Vojtíšek, Jiří ; Vítek, Martin (referee) ; Kolářová, Jana (advisor)
This work deals with long-therm analysis of electrocardiogram using heart rate variability representation. Project explains heart anatomy and electrophysiology, creation and shape of ECG curve. Heart rate variability is described by power spectral density, which we obtain from created algorithm. This algorithm was used in graphic user interface application Spider Pig Analysis, which analyze long-term ECG focused on showing Power Spectral Density graph. Practicality of this program was verified in experiment. In the experiment HRV at rest and HRV at tilt were compared.
Influence of breathe to baroreceptor reflex
Humpolík, Tomáš ; Janoušek, Oto (referee) ; Kolářová, Jana (advisor)
This Master's thesis deals with the influence of breathe to baroreceptor reflex. The first chapter is focused on measuring of blood pressure, in reference to later used method. In the second part is detailed analysis and explanation of term baroreflex, relationship between frequency spectra of systolic blood pressure, heart rate and breathing, mechanisms of regulation of blood pressure and heart rate variability. Third chapter deals with possible ways, how to analyze data, which are needed for estimation of baroreflex sensitivity, analyze of heart rate variability and estimation of power spectral density. Next parts of this thesis is paid attention to technical equipment and methods of acqusition of data, using this equipmnent. Part of this work is also software application, which makes possible from the recorded data estimate baroreflex sensitivity.
Noise generator
Pospíšil, Miroslav ; Kubásek, Radek (referee) ; Fiala, Pavel (advisor)
The goal of bachelor’s thesis „Noise generator“ is circuit design and construction of noise generator. The first part is concentrated on description of random signals. There are circuits of noise generators in the second part. In the third part is example of utilization noise generator in microwave sensors. And in fourth part are designed circuit and made measurements.
PROBLEM OF IDENTIFICATION OF DETERMINISTIC CHAOS IN THE INTERACTIVE DRIVE SYSTEMS
Kratochvíl, Ctirad ; Švéda, P. ; Houfek, Martin ; Houfek, Lubomír
Chaos and chaos theory is a field of study in mathematics, computer sciences, electronics, physics and also engineering too. In our article will be explored chaotic behaviour and numerical solutions of the models of drive systems with electric DC motors. These solutions are also bounded like equilibrium, periodic and quasiperiodic solution. There is no precise definition for a chaotic solution because it cannot be represented through standard mathematical functions. However, a chaotic solution is aperiodic solution, which is endowed with some special identifiable characteristics, for example attractors, bifurcations or one-and two dimensional maps.
Spectral analysis of continual and synthetic jet
Broučková, Z. ; Trávníček, Zdeněk ; Šafařík, P.
This experimental work deals with a characterization of three types of air jet flows (continual jet, synthetic jet and continual jet which is controlled by a synthetic jet). The characterization is performed using the power spectral density (PSD). All the characteristics were obtained from single-point measurements of flow velocity. The velocity was measured by a hot-wire anemometer (CTA). Power spectral density was acquired directly from measured signal (or from velocity data) by means of MATLAB software. Obtained graphs showed the control effect on the main flow behaviour. The significant qualitative change was revealed near a boundary of synthetic jet formation. Moreover it was concluded that this significant change can be also well quantified.
Measurements of Selected Parameters of the Flow Field in front of the Cascade TR-L-3
Hofer, Tomáš ; Kordík, Jozef ; Luxa, Martin ; Šimurda, David
The report contains the results and analysis of the pneumatic and thermoanemometric measurements performed on the inlet flow field upstream the turbine blade cascade TR-L-3. The description of the experiment covers the cases with and without the turbulent grid usage.
A proposal of methology for the estimation of durability of structures exposed to random loading
Svoboda, Jaroslav ; Balda, Miroslav
The paper describes results of fatigue tests, which have been carried out, on flat specimens with the notch in form of a hole in the middle. Specimens were loaded with three types of random blocks of 20 minutes duration. They mutually differed in a form of the power spectral density (PSD). All the PSDs were of linear form e.g. constant(white noise), linearly increasing and linearly decreasing in the frequency range 0-10Hz. Damage was measured and the method for estimation of live has been proposed.
Návrh metodiky výpočtu náhodně zatěžovaných konstrukcí
Svoboda, Jaroslav ; Balda, Miroslav
The report describes results of fatigue tests which have been carried out on flat speciments with the a hole in the middle. Speciments were loaded with three types of random blocks with 20 minutes duration. They mutually differed in a form of the power spectral density (PSD). All the PSDs were of linear form: constant,linearly increasing and linearly decreasing in the frequency range 0-10 Hz. The damage was observed and the metod for estimation of live for arbitrary form of PSD was proposed.
The influence of power spectral density on the crack propagation by the random loading
Svoboda, Jaroslav ; Mazanec, Jiří
The study of fatigue properties of the steel E460 proved that the form of the power spectral density influences the durability of test specimens stressed with a wideband random loading.
The influence of power spectral density on durability of the constructions under random loading
Svoboda, Jaroslav ; Václavík, Martin ; Balda, Miroslav
Paper follows the effect of power spectral density shape on fatigue life of three random wide-band processes with Gaussian amplitude distribution and frequency range 0-10 Hz. Compared are three modes: constant - white noise, linearly increasing and linearly decreasing.

National Repository of Grey Literature : 28 records found   beginprevious19 - 28  jump to record:
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