Julie Rousset is a graphic designer who designed a system
of graphic representation of the UST :

It's based on the UST classification developed by Xavier Hautbois^[1] :

This representation describes the morphology of the UST, in particular concerning the energy (strength, speed), the direction, the breaking points...

Other explanations in her site and in the proceedings of the colloquium Les UST, Nouvel outil d'analyse musicale, Théories et applications.