A Scale-Space Medialness Transform Based on Boundary Concordance Voting

The Concordance-based Medial Axis Transform (CMAT) presented in this paper is a multiscale medial axis (MMA) algorithm that computes the medial response from grey-level boundary measures. This non-linear operator responds only to symmetric structures, overcoming the limitations of linear medial operators which create “side-lobe” responses for symmetric structures and respond to edge structures. In addition, the spatial localisation of the medial axis and the identification of object width is improved in the CMAT algorithm compared with linear algorithms. The robustness of linear medial operators to noise is preserved in our algorithm. The effectiveness of the CMAT is accredited to the concordance property described in this paper. We demonstrate the performance of this method with test figures used by other authors and medical images that are relatively complex in structure. In these complex images the benefit of the improved response of our non-linear operator is clearly visible

Central limit theorem for an additive functional of the fractional Brownian motion II

We prove a central limit theorem for an additive functional of the $d$-dimensional fractional Brownian motion with Hurst index $H\in(\frac{1}{2+d},\frac{1}{d})$, using the method of moments, extending the result by Papanicolaou, Stroock and Varadhan in the case of the standard Brownian motion

On the importance of prismatic/basal interfaces in the growth of (-1012) twins in hexagonal close-packed crystals

The growth process of of (-1012) twins is studied in Magnesium using atomistic simulations. Two twin seeds are considered and both cases, a specific interface, which places face-to-face prismatic and basal planes, plays an important role. This interface has a low energy corresponding to a cusp in the orientation-dependent interface energy of a twinned bicrystal. This interface appears in several published twin structures and for instance accommodates the large deviations of twin interfaces from (-1012) planes reported recently [Zhang et al., Scr. Mater. 67 (2012) 862].Comment: 11 pages, 4 figures, submitted to Scripta Materiali

An evaluation technique for content interaction in web-based teaching and learning environments

Interactivity is a central element in teaching and learning. The Web as a new educational platform enables new forms of teaching and learning. The consequence for the Web – a constantly evolving environment that provides less direct feedback – is the importance of evaluation. In particular the learners’ interaction with the Web-based multimedia features is central. We propose Web usage mining, a technology that has already been used to analyse e-commerce Web sites, in conjunction with an analytic model as the evaluation approach