In view of the instability and low efficiency of the present image retrieval method, especially for simple image comparison with some salient shapes, a new image retrieval algorithm based on salient closed boundary is presented. Firstly, the Canny operator is performed to detect edges. Secondly, the ratio contour is used to extract the most salient closed boundary of some shape from the image. ...

Phasic right atrial and ventricular pressures and heart sounds were simultaneously recorded from dogs with normal and ectopic ventricular contractions. Heart sounds and electrocardiograms were recorded from humans. The first heart sound is significantly delayed in the absence of atrial systole. The time between onset of the ventricular pressure rise due to ventricular contraction and the beginn...

Species do not merely evolve, they also coevolve with other organisms. Coevolution is a major force driving interacting species to continuously evolve exploring their fitness landscapes. Coevolution involves the coupling of species fitness landscapes, linking species genetic changes with their inter-specific ecological interactions. Here we first introduce the Red Queen hypothesis of evolution ...

NK fitness landscapes are stochastically generated fitness functions on bit strings, parameterized (with genes and interactions between genes) so as to make them tunably ‘rugged’. Under the ‘natural’ genetic operators of bit-flipping mutation or recombination, NK landscapes produce multiple domains of attraction for the evolutionary dynamics. NK landscapes have been used in models of epistatic ...

Starting from fitness correlation functions, we calculate exact expressions for the amplitude spectra of fitness landscapes as defined by Stadler [1996. Landscapes and their correlation functions. J. Math. Chem. 20, 1] for common landscape models, including Kauffman's NK-model, rough Mount Fuji landscapes and general linear superpositions of such landscapes. We further show that correlations de...

Fig. 2. Results from one representative subject. (a) Selected ICs characterized by alpha modulation; (b) fMRI statistical maps contrasting eyes-open vs. eyes-closed; (c) Temporal averaged cortical source distribution underlying task-modulated alpha rhythm; (d) fMRI map from back view; (e) Spatially averaged alpha spectral power (red) vs. fMRI time course (blue) from occipital and parietal activ...

Our main result describes how to extend a matroid so that its ground set is a modular hyperplane of the larger matroid. This result yields a new way to view Dowling lattices and new results about line-closed geometries. We complement these topics by showing that line-closure gives simple geometric proofs of the (mostly known) basic results about Dowling lattices. We pursue the topic of line-clo...

We propose a control system for humanoid robot reaching using a motor-motor mapping that is learnt online. The system combines endpoint closed-loop and open-loop visual servo control. The closed-loop component moves the eyes, head, arm, and torso, based on the position of the target and the robot’s hand, as seen by the robot’s head mounted cameras. The learned, open-loop component brings the ha...

In both artificial and biological evolution, autocorrelation is commonly cited as a statistic which speaks to the “ruggedness”— and by implication evolvability— of a fitness landscape. But while the standard definition of autocorrelation involves uniform sampling of genotypes, it is a truism that evolution most decidedly does not sample a landscape uniformly. This is of particular significance ...