to date, a number of numerical methods, including the popular finite-difference time domain (fdtd) technique, have been proposed to simulate ground-penetrating radar (gpr) responses. despite having a number of advantages, the finite-difference method also has pitfalls such as being very time consuming in simulating the most common case of media with high dielectric permittivity, causing the for...

National Institute of Mental Health grant MH-63972, and NSF grant BCS-0446637. We would like to thank Malte Elson, Christopher Morris, and Helena Yardley for their help in collecting data. Acquiring experiential traces 2 Abstract Two experiments investigated the activation of perceptual representations of referent objects during word processing. In both experiments, participants learned to asso...

Michael N. Nunes Department of Computer Science University of Calgary [email protected]

In the classical Mazurkiewicz trace approach the behaviour of a concurrent system is described in terms of sequential observations that differ only with respect to their ordering of independent actions. This paper aims to determine a full generalisation of the trace model to the case that actions can be observed as occurring simultaneously. Thus observations are sequences of steps, i.e., sets o...

Provenance is information about the origin, derivation, ownership, or history of an object. It has recently been studied extensively in scientific databases and other settings due to its importance in helping scientists judge data validity, quality and integrity. However, most models of provenance have been stated as ad hoc definitions motivated by informal concepts such as “comes from”, “influ...