A graph is a split graph if its vertices can be partitioned into a clique and a stable set. A graph is a k-split graph if its vertices can be partitioned into k sets, each of which induces a split graph. We show that the strong perfect graph conjecture is true for 2-split graphs and we design a polynomial algorithm to recognize a perfect 2-split graph.

The scratching of pen against paper signaled something at once mundane and momentous. “What is your name, your age, your residence?” asked Harvey Risk, a representative of the Southern Claims Commission. “My name is Mary Blackburn.... My age is about forty-fi ve years. My residence near Middlebrook,” the claimant responded. The commission awarded compensation for property losses during the Amer...

In this paper we propose an architecture for using crossorganization information sharing to identify members of a group of hosts enslaved for malicious purposes on the Internet. We root our system in so-called “detectives”— savvy network monitors like sophisticated intrusion detection systems or honeyfarms that have a deep understanding of malicious behavior. We augment information from these d...

The enforced migration of Africans to the Americas in conditions of slavery lasted from the middle of the sixteenth century until the 1860s and constituted the largest movement of people across the Atlantic until the middle of the nineteenth century. Referred to as the notorious “Middle Passage” because of the terrible conditions on board slave ships, this migration involved at least 12 million...

It is difficult to make sweeping statements about the status of women during the first century because there were exceptions to any characterization that might be made. However, there were laws, widely accepted codes, and assumptions regarding roles of women. These provide insight into the sort of life women lived during this period. As might be expected, there was a wide range of lifestyles fo...

We present a method for generating exact diagonal G2-cosmological solutions in dilaton gravity coupled to a radiation perfect fluid and with a cosmological potential of a special type. The method is based on the symmetry group of the system of G2-field equations. Several new classes of explicit exact inhomogeneous perfect fluid scalar-tensor cosmologies are presented.

We define two decreasing filtrations by ramification groups on the absolute Galois group of a complete discrete valuation field whose residue field may not be perfect. In the classical case where the residue field is perfect, we recover the classical upper numbering filtration. The definition uses rigid geometry and log-structures. We also establish some of their properties.

A “perfect matching” of a graph G with n vertices is a set of n/2 independent edges of G. In the present study, we succeeded in determining the trees whose complements have the extremal number of “perfect matchings” for two different group of trees. Some further problems are also posed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem 105: 131–141, 2005

Let R be a perfect ring of characteristic p. We show that the group of continuous R-linear automorphisms of the perfect power series ring over R is generated by the automorphisms of the ordinary power series ring together with Frobenius; this answers a question of Jared Weinstein.

A practical method is presented that permits retrieval from a table in constant time. The method is suitable for large tables and consumes, in practice, O(n) space for n table elements. In addition, the table and the hashing function can be constructed in O(n) expected time. Variations of the method that offer different compromises between storage usage and update time are presented.