Fig. 1From: Unsupervised learning approach to automation of hammering test using topological informationHammering test conducted by a professional on the ceiling portion of a tunnel: only a simple hammer is needed thus the popularity of this non-destructive testing method. Still, there is the need of skilled operators to correctly differentiate hammering sounds and given the great population of structures in need of testing, automation is actively demanded. Also, since it relies heavily on the operator’s skills, the final result remains subjectiveBack to article page