This paper presents a new method for unsupervised change detection which combines independent component modeling and probabilistic outlier detection. The method further provides a compact data representation, which is amenable to interpretation, i.e., the detected condition changes can be investigated further. The method is successfully applied to unsupervised condition change detection in larg...

Detailed acoustical measurements were made in 41 active elementary school classrooms near Ottawa, Canada to obtain more representative and more accurate indications of the acoustical quality of conditions for speech communication during actual teaching activities. This study found: a mean speech-to-noise ratio in active classrooms of 11dBA, reverberation times from 0.3 to 0.6 s that were not re...

Acoustical materials are usually used for architectural design, ambient noise, and traffic noise to absorb sound. The sound absorption coefficient (SAC) is often as the performance index of acoustical materials. It measured using reverberation room method (RRM) impedance tube (ITM). source RRM a random incidence in various directions, whereas that ITM normal incident. SAC by more extensive, pra...

environmental noise pollution is among the most urban problems which can be caused due to real sources like traffic, train and virtual sources provided by rigid surfaces. one of the urban structures in which can perform as a virtual noise source are the installed gutters alongside highways. these structures are mostly used to pass the wastewater or the rainfall. in this research, the acoustical...