Abstract: A technique for tuning a silicon photonics (SiP) based nested (parent/child) Mach-Zehnder modulator (MZM). The technique includes a sequence of applying dither tones on individual arms of the child MZMs, observing changes in the output of the MZM, and adjusting the MZM until reaching the null points for the child MZMs and the quad point for the parent MZM.

Abstract: Provided are a method and device for recognizing spam short messages. In the method, a first feature word set is obtained in a spam short message sample set, and a first conditional probability of each feature word in the first feature word set is obtained; a second feature word set is obtained in a non-spam short message sample set and a second conditional probability of each feature word in the second feature word set is obtained; and a spam short message set is recognized from a short message set according to the number of words contained in each short message in the short message set to be processed, the number of repetition times of each short message in the short message set, the first feature word set, the second feature word set, the first conditional probability and the second conditional probability.