We show that every word hyperbolic, surface-by-(noncyclic) free group Γ is as rigid as possible: the quasi-isometry group of Γ equals the abstract commensurator group Comm(Γ), which in turn contains Γ as a finite index subgroup. As a corollary, two such groups are quasi-isometric if and only if they are commensurable, and any finitely generated group quasi-isometric to Γ must be weakly commensu...

The Chow flag varieties are introduced and studied. In a family of pure dimensional projective complex varieties defined via Chow flag varieties, the isomorphism type of Lawson homology of a general member in the family is discussed. Applications to morphic cohomology and motivic cohomology on smooth projective complex varieties are discussed.

This document presents the detailed design of the two main defense approaches under development within the project MILTIADES, namely the IP address space randomiza-tion proactive defense technique against hit-list worms, and the emulation-based poly-morphic attack detection technique.

A quasi-schemoid is a small category with a particular partition of the set of morphisms. We define a homotopy relation on the category of quasi-schemoids and study its fundamental properties. The homotopy set of self-homotopy equivalences on a quasi-schemoid is used as a homotopy invariant in the study. The main theorem enables us to deduce that the homotopy invariant for the quasi-schemoid in...

The word metric on a group is independent of the choice of generating set, so the quasiisometry type of a group is well defined. We say that two groups are (abstractly) commensurable if they are related to one another by any (finite) sequence of finite processes: taking finite-index subgroups or supergroups, finite quotients or extensions. Groups which are commensurable are quasi-isometric. The...

In this paper, we compute the number of fuzzy subgroups of some classes of non-abeilan groups. Explicit formulas are givenfor dihedral groups $D_{2n}$, quasi-dihedral groups $QD_{2^n}$, generalized quaternion groups $Q_{4n}$ and modular $p$-groups $M_{p^n}$.