Using wavelet transform (WT) for increasing signal-to-noise ratio (SNR) of discrete-time signals corrupted by additive noise is explained and compared with some other techniques (averaging, frequency filtration, correlation). Signal processing for de-noising is applied to basic periodical signals and repeated transients (in non-destructive ultrasonic testing of welds, where presence of flaws should be detected). Results of both computer simulations and measurements are reported, and some best suitable wavelets, levels of signal decomposition and methods and parameters of thresholding are given. A new efficient method of wavelet thresholding suitable for ultrasonic flaws detection in welds testing is described as a part of practical wavelets SNR enhancement (SNRE) application, and correlation function used for the same purpose is also described.. Wavelet Toolbox of MATLAB environment is used both for computer simulations and practical signal de-noising.

This paper describes a new sigma delta modulation technique. This technique is used for measurement of changes in half capacitive bridge to detect deflections, which can result from acceleration input in practice. The half bridge is connected to a modified flip-flop circuit, the outputs of which are used for one-bit force feedback. The modification of flip-flop consists in the implementation of a switched capacitor structure to achieve a perfect flip-flop value symmetry and compensation of a flicker noise. Some theoretical considerations are verified by experimental results. An experimental circuit has been constructed from discrete elements.

Image filtering by Richardson-Lucy algorithm show an iterative solution for monodimensional signal deconvolution. In this paper the performance of this algorithm will verified when LIDAR signals are pre- filtere by an adaprive low-pass filter. Most intresting results, for real-time deconvolution and filtering of lidar signal, will also showed.

The paper describes a prototype of ultrasonic distance/level meter. The meter is based on a digital signal processor (DSP), mandated to supervise its whole functioning. Besides driving the piezoelectric transducer, the DSP manages the digitization of the received ultrasonic signal, processes the acquired samples, according to a suitable measurement algorithm, and delivers the desired result to the final user. The measurement algorithm, already presented and validated, grants functionalities typically provided by analog circuitry, with a consequent reduction of the impact of production tolerances of analog components on measurement accuracy.
Meter’s performance has been assessed through a number of laboratory tests involving known distances in different measurement conditions. A comparison of the experienced performance to that granted by other meters available on the market finally corroborate the reliability and efficacy of the proposed meter.

The paper deals with sound intensity measurement technique and its application in dominant sound sources identification as well as the reduction of total radiated sound power from a complex technical system.
Based on more restrictive regulation and other demands, mainly related to the environment protection, noise attenuation of technical systems has become common task for. Often the only solution is only system redesign. To enable cost effective approach to this demand the paper exposes a rational methodoloque. The SI mapping is used as framework for sound power integration across the independent subsystems, ranking their contribution to the total system noise level and finally, optimizing redesigning process based on expenses and expected noise attenuation.
Paper presents results achieved through the diesel engine noise attenuation.