ambiguity is one of very important techniques in persian rhetoric, but in spite of its importance, it seems there is not enough accuracy in its definition and types.  the present essay tries to redefine the concept of ambiguity. we will begin by analyzing the definitions of ambiguity and amphiboly according to the old and new persian sources; then we presents a new definition and review and ana...

| We present results concerning three diierent types of quartic (fourth order) time-frequency distributions. First, we present new results on the recently introduced local ambiguity function, and show that it provides more reliable estimates of instantaneous chirp rate than the Wigner distribution. Second, we introduce the class of quartic, shift-covariant, time-frequency distributions, and inv...

The paper investigates the properties of ambiguity functions of 2-D analytic, quaternionic and monogenic signals. In the introduction the notions of the above signals and their Wigner distributions and ambiguity functions are recalled. The properties of the ambiguity functions are investigated using two kinds of test signals: A band-pass test signal in the form of a sum of two harmonic signals ...