Sub-direct product closed Fitting classes

On Arithmetical Classes Not Closed under Direct Union1

Closed Classes

A non empty class C of connected spaces is said to be a closed class if it is closed under weak equivalences and pointed homotopy colimits. A closed class can be characterized as a non empty class of connected spaces which is closed under weak equivalences and is closed under certain simple operations: arbitrary wedges, homotopy push-outs and homotopy sequential colimits. The notion of a closed...

Substitution-closed pattern classes

The substitution closure of a pattern class is the class of all permutations obtained by repeated substitution. The principal pattern classes (those defined by a single restriction) whose substitution closure can be defined by a finite number of restrictions are classified by listing them as a set of explicit families.

symmetry classes of polynomials associated with the ‎direct ‎product of permutation groups

‎let $g_{i} $ be a subgroup of $ s_{m_{i}}‎ ,‎ 1 leq i leq k$‎. ‎suppose $chi_{i}$ is an irreducible complex character of $g_{i}$‎. ‎we consider $ g_{1}times cdots times g_{k} $ as subgroup of $ s_{m} $‎, ‎where $ m=m_{1}+cdots‎ +‎m_{k} $‎. ‎in this paper‎, ‎we give a formula for the dimension of $h_{d}(g_{1}times cdots times g_{k}‎, ‎chi_{1}timescdots times chi_{k})$ and investigate the existe...

Direct Surface Fitting

In this paper, we propose a new method for estimating the shape of a surface from visual input. Assuming a parametric model of a surface, the parameters best explaining the perspective changes of the surface between different views are estimated. This is in contrast to the usual approach of fitting a model into a 3-D point cloud, generated by some previously calculated local correspondence matc...