invisibility

The algorithm ensures invisibility and robustness of the watermarking, while not affects information reading of the carrier QR barcode. Last, for the QR barcode as watermark information, propose a new watermarking algorithm evaluation criteria: the barcode reading rate.

该算法保证了水印的鲁棒性和不可见性，同时不影响载体QR条形码的信息识读。最后针对QR条形码作为水印信息，提出了一种新的水印算法评价标准：条码识读率。

Underwater launching missile has the advantages of invisibility and removability. But simultaneously it also involves the extremely complex physical process, from which the time-dependent ignition process of an underwater missile is most.

水下发射导弹具有隐蔽性和可移动性两大突出的优点，但同时也涉及极为复杂的物理过程。其中以导弹发动机水下点火初期的非定常过程为最甚。

We have gone a long way to get a comprehensive understanding of speech organs. Since many speech organs are in the mouth, the invisibility of these speech organs has been an obstacle for our understanding and study of speech production.

我们已经对发音部位有了比较全面的认识，但由于多数的发音器官位于口腔内，一般不容易观察到，这是语音发音研究的一大障碍。