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.
Making the world better, one answer at a time. Character study is defined as a work of fiction in which the delineation of the main character's personality is important. The main character's personality is considered more important the story's plot. Character study is defined as a work of fiction in which the delineation of the main character's personality is important.