We study the picture space X (G) of all embeddings of a finite graph G as point-andline arrangements in an arbitrary-dimensional projective space, continuing previous work on the planar case. The picture space admits a natural decomposition into smooth quasiprojective subvarieties called cellules, indexed by partitions of the vertex set of G, and the irreducible components of X (G) correspond t...

The ground-state properties of the t-J model on a d-dimensional hypercubic lattice are examined in the limit of large d . It is found that the undoped system is an ordered antiferromagnet, and that the doped system phase separates into a hole-free antiferromagnetic phase and a hole-rich phase. The latter is electron free if J.4t and is weakly metallic ~and typically superconducting! if J,4t . T...

Based on Jordan Curve Theorem, a universal classification method called hyper surface classification (HSC) has recently been proposed. Experimental results are exciting, which show that in three-dimensional space, this method works fairly well in both accuracy and efficiency even for large size data up to 107. However, designing a number of new classifiers is needed with the growing of feature ...