A method for precise sound sources detection and localization in interiors is presented. Acoustic vector sensors, which provide multichannel output signals of acoustic pressure and particle velocity were employed. Methods for detecting acoustic events are introduced. The algorithm for localizing sound events in the audience is presented. The system set up in a lecture hall, which serves as a demonstrator of the proposed technology, is described. The accurracy of the proposed method is evaluated by the described measurement results. The analysis of the results is followed by conclusions pertaining the usability of the proposed system. The concept of the multimodal audio-visual detection of events in the audience is also introduced.
In this paper the development and method of production of modern, Ni-free sintered structural steels containing Cr, Mn and Mo, enabling the production of structural sintered steels in industrial conditions, using safe, with low H2-content, sintering atmospheres is presented. For this purpose, the analysis of microstructure and mechanical properties of these sintered structural steels produced in different processing conditions and also the connections between the microstructure of sintered material and its mechanical properties, was presented. Following the investigations, the appropriate chemical composition of sintered Ni-free steels with properties which are comparable or even better than those of sintered structural steels containing rich and carcinogenic nickel was choosen. Additionally, in the paper the properties of electrolitically coated carbon steels were presented, as the beginning of investigation for improving the mechanical properties of alloyed, structural sintered steels.