Transcranial Doppler (TCD), first described in 1982 [1], is a noninvasive ultrasound (US) study that involves the use of a low-frequency (â¤2 MHz) transducer probe to insonate the basal cerebral arteries through relatively thin bone windows.
Details. as.character and is.character are generic: you can write methods to handle specific classes of objects, see InternalMethods. Further, for as.character the default method calls as.vector, so dispatch is first on methods for as.character and then for methods for as.vector.
In this method, every user has the same encryption algorithm and the key. The decryption algorithm and the key, however, are kept secret. Anyone can encrypt the information, but only an authorized receiver can decrypt it. Character-Level Encryption In this method, encryption is done at the character level.