Wilfrid Sellars is widely known for two positions that he calls “nominalism.” On the one hand, there his “psychological nominalism,” according to which any awareness might have of abstract entities—be they properties, relations, or facts—is a thoroughly linguistic affair, and so cannot be presupposed in thinking about process learning (first) language. other ontological nominalism, world, as it...

This talk is based on a joint paper with A. Bonami and G. Garrigós [3] in which the phase retrieval problem for the Radar Ambiguity Function (i.e. the Radar Ambiguity Problem) has been tackled. In particular it was shown that for wide classes of signals, the radar ambiguity problem has a unique solution, up to trivial transformations. In the second part of the talk, we report on ongoing work by...

By using the fractional Fourier transformation of the time-domain signals, closed-form expressions for the projections of their auto or cross ambiguity functions are derived. Based on a similar formulation for the projections of the auto and cross Wigner distributions and the well known two-dimensional (2-D) Fourier transformation relationship between the ambiguity and Wigner domains, closed-fo...

Al-Najjar and Weinstein 2009 propose to scrutinize the implications of recent theories of ambiguity in dynamic settings. They conclude that such implications are so unreasonable as to cast doubts on the legitimacy of the theories under consideration. The present paper argues that the seemingly unreasonable implications highlighted by Al-Najjar and Weinstein can be understood as the result of ba...