The first examples of complete projective connections are uncovered: normal projective connections on surfaces whose geodesics are all closed and embedded are complete, as are normal projective connections induced from complete affine connections with slowly decaying positive Ricci curvature. Moreover, I explain the relationship between projective and affine connections.

We will show methods for interpolation of viewpoint from multiple cameras based on projective geometry. Projective relationship of multiple cameras can be obtained from weak calibration information, that can easily be corrected from the multiple view images. Such projective geometry provides sufficient information to reconstruct the 3D shape of the object with scale and projective transformatio...

If R is a ring of coefficients and G a finite group, then a flat RG-module which is projective as an R-module is necessarily projective as an RG-module. More generally, if H is a subgroup of finite index in an arbitrary group Γ, then a flat RΓmodule which is projective as an RH-module is necessarily projective as an RΓ-module. This follows from a generalization of the first theorem to modules o...

‎in [u‎. ‎dempwolff‎, ‎on extensions of elementary abelian groups of order $2^{5}$ by $gl(5,2)$‎, ‎textit{rend‎. ‎sem‎. ‎mat‎. ‎univ‎. ‎padova}‎, ‎textbf{48} (1972)‎, ‎359‎ - ‎364.] dempwolff proved the existence of a group of the‎ ‎form $2^{5}{^{cdot}}gl(5,2)$ (a non split extension of the‎ ‎elementary abelian group $2^{5}$ by the general linear group‎ ‎$gl(5,2)$)‎. ‎this group is the second l...

In this handout we will briefly explore the topic of projective modules in a bit more detail than we covered in class. Throughout R is a commutative ring. Recall that, by definition, a projective module is an R-module that is a direct summand of a free R-module. As mentioned in class, if the ring R is decomposable, e.g., R = R1 ⊕R2 is a direct sum of rings, then there are many examples of non-f...

We generalize the notion of Jacobson graphs into $n$-array columns called $n$-array Jacobson graphs and determine their connectivities and diameters. Also, we will study forbidden structures of these graphs and determine when an $n$-array Jacobson graph is planar, outer planar, projective, perfect or domination perfect.

In this paper, we consider the projective special linear group $PSL_2(59)$ and construct some 1-designs by applying the Key-Moori method on $PSL_2(59)$. Moreover, we obtain parameters of these designs and their automorphism groups. It is shown that $PSL_2(59)$ and $PSL_2(59):2$ appear as the automorphism group of the constructed designs.

Projective texture mapping is a method of texture mapping described by Segal [3] that allows the texture image to be projected onto the scene as if by a slide projector. Figure 1 shows some example screen shots from the projspot demo, available in the NVIDIA OpenGL SDK. Projective texture mapping is useful in a variety of lighting techniques, including shadow mapping [4]. This document provides...