Physically Based Rendering Techniques

When the room to be simulated doesn t exist, we can attempt to predict its impulse response based on purely physical considerations. This requires detailed knowledge of the geometry of the room, properties of all surfaces in the room, and the positions and directivities of the sources and receivers. Given this prior information, it is possible to apply the laws of acoustics regarding wave propagation and interaction with surfaces to predict how the sound will propagate in the space. This technique has been termed auralization in the literature and is an active area of research [Kleiner et al., 1993]. Typically, an auralization system first computes the impulse response of the specified room, for each source-receiver pair. These finite impulse response (FIR) filters are then used to render the room reverberation. 

Characterization of HME-based solid dispersions is not solely motivated by the need to directly measure physical failure. By extension, characterization tools and techniques provide insight into the fundamental properties which facilitate physical failure. For instance, measures of the thermodynamic properties and modes of motion associated with amorphous systems serve to better assess risk of physicochemical failure. Also, as was noted above, in several instances, although the material may be rendered amorphous, the differences in length scale of mixing may manifest as differences in performance, and, thus, characterization tools also inform process development. 

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