Application of ICAMM to Impact-Echo Testing - On Statistical Pattern Recognition in Independent Component Analysis Mixture Modelling - page 110

Fig. 5.3 Examples of the different patterns of defective materials. The multichannel setup of the
impact-echo inspection is displayed
marble stones (5-9 m 3 , 6-10 tons of weight). This study combined single-channel
impact-echo testing and ultrasound for general classification of the status of marble
rocks into either sound or unsound material. The marble rock defects feature a
range of different shapes and sizes with volumes up to the order of cm 3 . Thus, an
acoustic-wave NDT system is appropriate for the application of general marble
diagnosis with capabilities to determine material defective zones and to classify
the general status of the block, depending on a given detail level of defect types.
5.3.1 ICA Mixture Statement of the Problem
First of all, note that the aim of this section is to find an underlying ICA mixture
model from physical reasoning. This will contribute to a better understanding of
the suitability of ICAMM to the impact-echo problem, as well as contribute to a
better interpretation of the obtained results. A detailed description of the proposed
procedure and the criteria for fitting the different parameters involved is included
in the experimental section of this approach.