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.
Characterization refers to the methods used by the author to create or reveal the characters in a story. The most common methods of revealing the characters are: (1) by what the character says or thinks; (2) by what the character does; and (3) by what other characters say about the character.