This paper introduces a new and effective method of RMS value estimation in time domain. The new approach is based on signal windowing without subsequent processing in frequency domain. Examples of newly obtained analytical formulae, comparison to the classical method and extension to multi-frequency signals are presented. Both numerical simulation and measurements are used to verify the derived formulae. The first findings based on this new method were presented in [1].
The paper compares nine methods of measurement of the phase difference of digitized sinusoidal noised signals according to their sensitivity to sampling non-integer number of signal periods. The investigated methods can be classified into four groups - modifications of classical zerocrossing based measurements, DFT-based measurements, virtual vector voltmeter and modifications of sine-wave fit algorithm. Results of both simulations and measurements are presented.
The main purpose of the paper is to present a new approach to calculation of uncertainties in harmonic contents, which are induced due to imperfection of acquired values of samples. The acquired samples are representing true values but every sample is bearing errors caused by all front end elements wired to Analogue to Digital Converter, ADC, and errors of ADC converter itself. The method is similar to uncertainty distribution through measurement model, but the difference is in generation of distribution. The distribution is not generated for each sample itself and each all possible variants...
The paper presents accelerated impedance spectrum measurement method, oriented for measuring the quality of anticorrosion coating, modelled by a linear equivalent circuit. The method is based on applying multisine stimulation signal. Both stimulation and object response are analysed in frequency domain by digital filter bank. The theoretical description of method and a proposition of measurement methodology are presented. The simulation results are discussed, concerning spectrum calculation error and acceleration of measurements for several shape-designed multisine signals.
The paper presents results of investigations on the use of a mixed-signal test bus IEEE 1149.4 for measurements of passive RLC elements placed on electronic circuit boards. In the tests integrated circuits the STA400, the first commercial integrated circuits compliant with the IEEE 1149.4, were used. Measurements were carried out using methods proposed in the IEEE 1149.4 standard as well as newly-developed methods oriented at bus testing. The methodology of measurements and the achieved results are also presented.
The paper deals with the test signal selection to be adopted for the Voice Quality Measurement (VQM) in telecommunication networks. It is proposed to use the optimized multisine as test signal in place of both the natural and the artificial voices, suggested by the ITU-T recommendations. The effectiveness of the optimized multisine to the VQM is investigated by using four algorithms: (i) Perceptual Speech Quality Measurement, (ii) Perceptual Speech Quality Measurement plus, (iii) Perceptual Evaluation of Speech Quality, and (iv) Perceptual Analysis Measurement System. Numerical tests are...
The method to assess uncertainty in measuring the power spectrum density of a random waveform is presented. Then, the evaluation of assessing uncertainty of power spectrum density is carried out. It takes into account propagation of uncertainties associated with each sample recording in the algorithm of digital signal processing and an error of the estimator bias resulting from a mathematical model of the measured value. The dependences for uncertainties in measuring the power spectrum density of a random waveform are introduced.
The use of medians as filtering windows in digital signal processing is known since many years and applied especially when linear filters could not be used, because of specific character of disturbances which are to be removed. This is the case, if, for instance, impulsive disturbances, having very wide spectra, are observed, and linear filters are not suitable for their elimination. Median procedures, including also weighted medians, are particularly effective in such filtering procedures. According to the applied algorithm, disturbed signal samples are eliminated and replaced by some...
This paper presets a study of a fuel cell placed on an experimental car kit and an analysis of the energetic regime for this kit, supplied by the fuel cell and by a solar panel. It was estimated the efficiency of the supply elements. The energetic regime at the level of supply of kit motor depends by the illumination degree of solar panel and by the driving torque that the motor must to develop it for motion. These factors will influence also the conversion processes at fuel cell level.
During last years, ion track technology has attracted considerable attention. This technology uses as support polymer foils irradiated with ion beams produced by heavy ions accelerators. Accelerated ions passing through these foils produce latent ion tracks by breaking the polymer chains [1]. Latent ion tracks can be selectively removed by chemical etching and obtain nanopores with diameters going down to 10nm. Nanopores can be used as they are or can be filled with metals to obtain nanowires [2]. Both, the etching process and the electrodeposition can be performed in the same...