In many bird monitoring surveys, no attempt is made to estimate bird densities or abundance. Instead, counts of one form or another are made, and these are assumed to correlate with bird density. Unless complete counts on sample plots are feasible, this approach can easily lead to false conclusions, because detectability of birds varies by species, habitat, observer and many other factors. Tren...

A notion of detectability for nonlinear systems is discussed. Within the framework of “input to state stability” (ISS), a dual notion of “output to state stability” (OSS), and a more complete detectability notion, “input-output to state stability” (IOSS) have appeared in the literature. This note addresses a variant of the IOSS property, using an integral norm to measure signals, as opposed to ...

Abstract Several studies demonstrate the effectiveness of pulsed thermography for detection and visualization sub-superficial flaws in composites. Continuous improvement thermal data manipulation makes active an attractive powerful inspection method industrial process control maintenance aims. Therefore, temperature image-processing is major ongoing challenge thermographic research field. Howev...

Rotation dynamics of eigenvectors of modular network adjacency matrices under random perturbations are presented. In the presence of q communities, the number of eigenvectors corresponding to the q largest eigenvalues form a "community" eigenspace and rotate together, but separately from that of the "bulk" eigenspace spanned by all the other eigenvectors. Using this property, the number of modu...

A procedure is described for the automatic derivation of aspect graphs of surface-based geometric models. The object models are made of finite, typed, second order surface patches allowing the representation of a large number of complex curved objects while retaining ease of recognition. A new representation, the detectability sphere, is developed to encode feature detectability constraints. Th...

We define observability and detectability for linear switching systems as the possibility of reconstructing and respectively of asymptotically reconstructing the hybrid state of the system from the knowledge of the hybrid outputs for a suitable choice of the control input. We derive a necessary and sufficient condition for observability that can be verified computationally. A characterization o...