Depth maps taken by the low cost Kinect sensor are often noisy and incomplete. Thus, post-processing for obtaining reliable depth maps is necessary for advanced image and video applications such as object recognition and multi-view rendering. In this paper, we propose adaptive directional filters that fill the holes and suppress the noise in depth maps. Specifically, novel filters whose window ...

We propose topology-based maps as a new representation of the workspace of a mobile robot. These maps capture the structure of the free space in the environment in terms of the basic topological notions of con-nectivity and adjacency. Topology-based maps can be automatically extracted from an occupancy grid built from sensor data using techniques borrowed from the image processing eld. Since th...

In this paper we report on progress using ambient noise correlation with a dense 3D survey conducted in Long Beach, California, to estimate subsurface velocity. We show that both Rayleigh wave and body wave signals can be clearly observed between 0.2-10 Hz frequency range in the noise cross-correlations. The observed signals also compare well with an active source gather. We apply eikonal tomog...

The effect of noise is studied in one-dimensional maps undergoing transcritical, tangent, and pitchfork bifurcations. The attractors of the noiseless map become metastable states in the presence of noise. In the weak-noise limit, a symplectic two-dimensional map is associated with the original one-dimensional map. The consequences of their noninvertibility on the phase-space structures are disc...

The effect of stochastic perturbations on nearly homoclinic pulse trains is considered for three model systems: a Duffing oscillator, the Lorenz-like Shimizu-Morioka model, and a co-dimension-three normal form. Using the Duffing model as an example, it is demonstrated that the main effect of noise does not originate from the neighbourhood of the fixed point, as is commonly assumed, but due to t...

Scholars writing books that are widely used to support teaching in higher education may be undervalued due to a lack of evidence of teaching value. Whilst sales data may give credible evidence for textbooks, it may poorly reflect educational uses of other types of books. As an alternative, this article proposes a method to automatically search for mentions of books in online academic course syl...