Quote Originally Posted by zonepress View Post
το οποίο εκπέμπεται σε ανάστροφη πολικότητα (=το "αγκάθι" στην 10η κυματομορφή) ως προς το στάσιμο με σκοπό την αλληλοακύρωση.
Στη συνέχεια υπολογίζει εμμέσως το Q:
Για τους λιγότερο γνώστες

In physics and engineering the quality factor or Q factor is a dimensionless parameter that compares the time constant for decay of an oscillating physical system's amplitude to its oscillation period. Equivalently, it compares the frequency at which a system oscillates to the rate at which it dissipates its energy. A higher Q indicates a lower rate of energy dissipation relative to the oscillation frequency, so the oscillations die out more slowly. For example, a pendulum suspended from a high-quality bearing, oscillating in air, would have a high Q, while a pendulum immersed in oil would have a low one.

The concept originated in electronic engineering, as a measure of the 'quality' desired in a good tuned circuit or other resonator.
http://en.wikipedia.org/wiki/Q_factor