The traditional opinion sentence recognition tasks mainly realize the classification by emotional features inside the sentence. In the task of cross-lingual multi-document opinion sentence recognition, the certain supporting function for opinion sentence recognition was provided by the association between sentences in different languages and documents. Therefore, a Chinese-Vietnamese bilingual multi-document news opinion sentence recognition method was proposed by combining Bi-directional Long Short Term Memory (Bi-LSTM) network framework and sentence association features. Firstly, emotional elements and event elements were extracted from the Chinese-Vietnamese bilingual sentences to construct the sentence association diagram, and the sentence association features were obtained by using TextRank algorithm. Secondly, the Chinese and Vietnamese news texts were encoded in the same semantic space based on the bilingual word embedding and Bi-LSTM. Finally, the opinion sentence recognition was realized by jointly considering the sentence coding features and semantic features. The theoretical analysis and simulation results show that integrating sentence association diagram can effectively improve the precision of multi-document opinion sentence recognition.

Since the computational complexity of public key cryptography is high, and Power Delay Profile (PDP) model is limited by the distance between the attacker and the user, a wireless communication security strategy based on Differential Flag Byte (DFB) was proposed in the identification and defense of impersonation attack. Meanwhile, the equation to generate the DFB was given. The strategy utilized the transmission data information to generate the DFB equation, establishing the correlation that current flag byte of transmission data frame was determined by the relevant parameter of last frame. Finally, receiving terminal identified attack by testing and verifying the DFB received from the data frame with threshold decision. Through theoretical analysis, DFB could prevent recurrent impersonation attack, when the attacker knew the communicational parameter. Meanwhile, the attacker's effective attack time was shorter, and the attack cycle was longer. And the attacker was limited to a finite ellipse in space. Simulation analysis was carried out with a simple DFB at the end. The results show that wireless communication based on the simple DFB strategy can identify and defense impersonation attack by setting the appropriate threshold, when the communication system's Signal-to-Noise Ratio (SNR) was above -4 dB.