  We develop theoretical formulas for the prediction of the rupture of systems
which are known to exhibit a critical behavior, based solely on the knowledge
of the early time evolution of an observable, such as the acoustic emission
rate as a function of time or of stress.
  From the parameterization of such early time evolution in terms of a
low-order polynomial, we use the functional renormalization approach introduced
by Yukalov and Gluzman to transform this polynomial into a function which is
asymptotically a power law. The value of the critical time tc,conditioned on
the assumption that tc exists, is thus determined from the knowledge of the
coefficients of the polynomials. We test with success this prediction scheme
with respect to the order of the polynomials and as a function of noise.
