Re search G roup on I ntelligent M achines

1. National School of Engineers of Sfax REsearch Group on Intelligent Machines ResearchGrouponIntelligentMachines Prediction of Psychophysical Laws with the Beta-Elliptic Model Production of handwriting requires a hierarchically organized flow of information undergoing a series of transformations. Hala Bezine IGS 2011 - Live Aqua Cancun, MEXICO On-line handwriting script Extraction of the curvilinear velocity signal V(t) Generation of the Beta profiles with the kinematic parameters (t0, tc, t1, p, q, H) for each stroke Extraction of the associated static parameters (a, b, X0, Y0, θ0) related to the elliptic shape Regeneration of the original handwriting script with Beta-elliptic strokes Extraction of a simple stroke (a) in the velocity domain (b) in the trajectory domain

2. Prediction of psychophysical laws with the Beta-elliptic model • The relation between the dynamics and the shape of a handwriting movement Use spiking neural networks. • An elliptic trajectory leads to a velocity signal that can be fitted with a Beta profile. • For different conditions most psychophysical laws are verified such as isochrony, speed and size scaling. The model yields to the isochrony principle, and the writing time is not unchanged across changes in writing size, but increases by a small amount The amount of time of the writing task decreases, if the speed increases. Hala Bezine IGS 2011 - Live Aqua Cancun, MEXICO Example of Arabic letter « س » generated for three times with variable velocity and constant shape, with the respective curvilinear velocity profiles Vx and Vy Example of Arabic letter «و »generated for three times with constant velocity and variable shape