The subject of this master’s thesis is „Frequency method for investigation discreet regulation systems“. It’s primary conversant of constructing frequency characteristics for discreet systems. The works has a two parts. The firs part indicates provides theoretical information and the basic relations needed to clarify construction of frequency characteristics continuous and discrete systems too. The second part includes main job description given by the headman of this thesis. It’s consisting of constructing catalogue of the frequency discrete characteristics for discrete systems and creation program for calculation and construction of this systems.

<p> Centre of pressure (CP) excursion frequency characteristics of normal and visually impaired children were examined. Thirty-six normal (N) children and 12 visually impaired (VI) children stood on a force platform under 4 conditions (eyes open or closed, normal or foam surface). CP excursions were analyzed by fast Fourier transformation. Total power was calculated between 0-4 Hz, and percent of total power was calculated in the low (0-1 Hz) and high (1-4 Hz) bands. Linear regression was performed on logarithmically transformed data and the slope was used to compare the relative power at low and high frequencies. Analysis of covariance removed the variance due to height in the N children. The Mann-Whitney test compared theN and VI children. Total power decreased with age. Young children (4-7 years) had more high frequency power. Young children may respond intermittently to feedback with ballistic type movements while older children may continuously monitor and respond to sensory feedback. Vision helped control CP adjustments, but power did not increase between 0-1 Hz with eyes closed. VI had higher total power on the normal surface. With eyes closed the differences were more obvious in the older children (10-12 years) which suggests vision is important in development to fine-tune the sensory systems. The foam reduced pressor receptor feedback, reducing the advantage of more finely tuned somatosense in N children. VI children had more low frequency power than N children (A-P). Young VI children did not have a large amount of high frequency power, as the N children did, suggesting that VI children may adapt at a younger age to continuously monitor and respond to feedback without relying on intermittent ballistic type responses. </p> / Thesis / Master of Science (MSc)

Discussion of the application of mathematical softwares for the determination of frequency characteristics of mechanical systems

This work provides an overview of methods for the numerical solution of differential equations. Options of their parallelization, a division of computational operations on multiple microprocessors, are provided with emphasis placed on the Taylor series. The next part of the work is devoted to the description of a specialized parallel system, which was design to fast solving of these equations. Differential equations are appropriate to describe electrical circuits. An important characteristic of each circuit is its behavior in the frequency domain. The aim of this thesis was to design and implement a program which investigate frequency characteristics of AC circuits. A method for analyzing a circuit and automatically assembling corresponding equations is presented. These differential equations are then solved in TKSL. At the end of this work a time consumption is evaluated and compared with Matlab.

This master's thesis describes functionality and principle of the Hefaistos measurement system, which is fully automated and modular. Its purpose is to measure frequency responses of materials and its temperature dependence. The thesis describes all the necessary parts of the modular measurement system. Main part of this system is the control application programmed in LabVIEW software environment. Another necessary parts are impedance analyzers for acquiring frequency dependencies and heating chambers for heating measured materials. The control application ensures hardware synchronization between impedance analyzers and heating chambers. Together they create the Hefaistos system. Modularity of the system means that a user may choose which instrument combination will be used. The system offers choice between three impedance analyzers Agilent 4294A, Wayne Kerr 6520B and HIOKI 3532 LCR Hi-Tester and two heating chambers AOIP GEMINI 700 LRI and AOIP HYPERION. Possibilities of the Hefaistos system are demonstrated on the results of an example measurement.

Master’s thesis deals with the issue of electronic filtering circuits with arbitrary frequency characteristics. First part of the thesis describes theoretical basis. Second part explores the possibilities of design procedures for filters with arbitrary frequency characteristics. Design procedures are demonstrated on examples accordingly to the presented methods, including their circuit implementation and computer simulation to verify the correctness of theoretical assumptions. Thesis also explores the possibilities of tuning circuit structures and electronic setting for characteristics using controllable active elements.

The aim of this thesis was to develop user interface in LabVIEW to make typical measurements with spectral analyzer HP89410A There is introduced the theory of operation of an analogue heterodyne and a digital FFT spectral analyzer. It is explained the background of the Fast Fourier Transform. There are discussed the key settings in measuring with FTT analyzer, like window function, bandwidth, number of frequency points, or the averaging. Further is described the program, which was developed for measuring frequency characteristic by white noise and by stepped measurement. It was also made a module for measuring Signal to Noise Ratio and module for Total Harmonic Distortion. In the last part of this thesis are shown the results of processed exemplar measurements.

This diploma work deals with active circuit elements and proposals of methods for measuring of some parameters of these elements. In the opening part the work deals with general classification of elements used in electronic circuits, ideal and real current sources and power supplies. Further there are stated basic parameters and characteristics presented by producers in a catalogue sheet for active elements MAX435, OPA660, AD844 and MAA741 element which already belongs to the history of IC. Main attention is paid to active circuit elements with current sources driven by CCCS (Current Controlled Current Source) and AD844 (high speed monolithic operational amplifier). In the work there is described a method for determining of selected parameters of active elements with CCCS. Examined parameters were frequency characteristics of current transfer, input impedance and output impedance. The proposed method was verified by a computer simulation on above mentioned active elements by means of PSpice software. Findings along with the description are summarized at the end of the work. In the closing part of the work there is undertaken a real measure of AD844 element based on the proposed method and the findings are compared with particular simulations. However, at first a flat connection board was made by means of EAGLE software and then the measure was performed on it.