2-D projective moment invariants were firstly proposed by Suk and Flusser in [12]. We point out here that there is a useless projective moment invariant which is equivalent to zero in their paper. 3-D projective moment invariants are generated theoretically by investigating the property of signed volume of a tetrahedron. The main part is the selection of permutation invariant cores for multiple...

This paper contains four main results associated with an attractor of a projective iterated function system (IFS). The first theorem characterizes when a projective IFS has an attractor which avoids a hyperplane. The second theorem establishes that a projective IFS has at most one attractor. In the third theorem the classical duality between points and hyperplanes in projective space leads to c...

This paper contains four main results associated with an attractor of a projective iterated function system (IFS). The first theorem characterizes when a projective IFS has an attractor which avoids a hyperplane. The second theorem establishes that a projective IFS has at most one attractor. In the third theorem the classical duality between points and hyperplanes in projective space leads to c...

An R-module M is called epi-retractable if every submodule of MR is a homomorphic image of M. It is shown that if R is a right perfect ring, then every projective slightly compressible module MR is epi-retractable. If R is a Noetherian ring, then every epi-retractable right R-module has direct sum of uniform submodules. If endomorphism ring of a module MR is von-Neumann regular, then M is semi-...

In this article we prove two new criteria for the existence of rational general integral of an algebraic differential equation (cf. [4]) on the complex projective plane. These results are stated in terms of divisors and zero-cycles of a projective variety and are built by using intersection numbers of projective curves and multiplicities of singularities. We also prove a new result giving new s...

In most languages, most of the syntactic dependency relations found in any given sentence are projective: the word-word dependencies in the sentence do not cross each other. Some syntactic dependency relations, however, are non-projective: some of their word-word dependencies cross each other. Non-projective dependencies are both rarer and more computationally complex than projective dependenci...

These are notes for a talk at a topology seminar at ND. 1. GENERAL FACTS In the sequel, for simplicity we denote the complex projective space CPN by PN , and we denote the projective coordinates by [~z] = [z0, . . . , zN ]. A smooth projective variety is a connected compact complex submanifold of some projective space PN . All the smooth projective varieties are Kähler manifolds, but the conver...