Constant propagation (CP) is one of the most widely used optimizations in practice (cf. [9]). Intuitively, it addresses the problem of statically detecting whether an expression always evaluates to a unique constant at run-time. Unfortunately, as proved by different authors [4, 16], CP is in general undecidable even if the interpretation of branches is completely ignored. On the other hand, it ...

Two sets of points in -dimensional space are given: a data set consisting of points, and a pattern set or probe consisting of points. We address the problem of determining whether there is a transformation, among a specified group of transformations of the space, carrying into or near (meaning at a small directed Hausdorff distance of) . The groups we consider are translations and rigid motions...

Successive interference cancellation (SIC) is a physical layer technique that enables the decoders to decode multiple simultaneously transmitted signals. The complicated model of SIC requires careful design of the MAC protocol and accurate adjustment of transmission parameters. We propose a new MAC protocol, known as CSMA-SIC, that employs the multi-packet reception capability of SIC. The propo...

We have obtained nonperturbative one-loop expressions for the mean energy-momentum tensor and current density of Dirac's field on a constant electric-like background. One of the goals of this calculation is to give a consistent description of back-reaction in such a theory. Two cases of initial states are considered: the vacuum state and the thermal equilibrium state. First, we perform calculat...

Sound propagation has been studied in a magnetically trapped dilute Bose-Einstein condensate. Localized excitations were induced by suddenly modifying the trapping potential using the optical dipole force of a focused laser beam. The resulting propagation of sound was observed using a novel technique, rapid sequencing of nondestructive phase-contrast images. The speed of sound was determined as...

Single-scattering theory is shown to be insufficient for the estimation of effective propagation constant in foliage at high microwave and millimeter-wave frequencies. Clusters of broad leaves and needles are treated as a unit scatterer whose ensemble forward scattering is used in Foldy’s approximation to estimate attenuation rate in foliage. It is shown that single-scattering approximation ove...