We propose a method for determining the shape (2D outline of the object) and follow-up position (set of simple geometric transformations on position), using a level set based curve evolution and combining the benefits of using the pixel-wise posterior term with a fast level-set algorithm to approximate curve evolution. The pixelwise posterior allows us to marginalize the model parameters at pix...

homogeneity and uniformity of soil particles is a most potent factor which affects soil spectral signatures. geometric standard deviation of soil particles (?g) exhibits the homogeneity of soil components. this study presents the influence of ?g on spectral studying of soil geometric mean particle diameter as well as lime. the study was conducted in pol-e-dokhtar using the data set of lissiii-p...

An algorithm is proposed to give a global approximation of an implicit real plane algebraic curve with rational quadratic B-spline curves. The algorithm consists of four steps: topology determination, curve segmentation, segment approximation and curve tracing. Due to the detailed geometric analysis, high accuracy of approximation may be achieved with a small number of quadratic segments. The f...

Let M be a matroid and F the collection of all linear orderings of bases ofM. orflags of M. We define the flag matroid polytope A(F)We determine when two vertices of A(F) are adjacent, and provide a bijection between maximal chains in the lattice of flats of M and certain maximal faces of A(F).

Appearance-based object recognition systems rely on training from imagery, which allows the recognition of objects without requiring a 3D geometric model. It has been little explored whether such systems can be trained from imagery that is unlabeled, and whether they can be trained from imagery that is not trivially segmentable. In this paper we present a method for minimally supervised trainin...

The secondary polytope of a point configuration A is a polytope whose face poset is isomorphic to the poset of all regular subdivisions of A. While the vertices of the secondary polytope – corresponding to the triangulations of A – are very well studied, there is not much known about the facets of the secondary polytope. The splits of a polytope, subdivisions with exactly two maximal faces, are...

Distributive supermatroids generalize matroids to partially ordered sets. Completing earlier work of Barnabei, Nicoletti and Pezzoli we characterize the lattice of flats of a distributive supermatroid. For the prominent special case of a polymatroid the description of the flat lattice is particularly simple. Large portions of the proofs reduce to properties of weakly submodular rank functions. ...