A recurrent 2-dimensional (double) sequence t(m,n) is given by fixing particular sequences t(m, 0), t(0, n) as initial conditions and a rule of recurrence t(m,n) = t(a(m,n − 1), t(m − 1, n − 1), t(m − 1, n)) for m,n ≥ 1. We display such a sequence with values in the set {0, 1} and show that all rows are periodic and that the minimal period of the n-th row has length 2. We conclude that this 2-d...

This study concerns the relationship between gender and job performance among brokerage firm equity analysts. Women’s representation in analyst positions dropped from 16 percent in 1995 to 14 percent in 2005. The study found significant gender-based differences in performance on various dimensions. For example, women cover roughly 9 stocks, on average, as compared with 10 for men, and women’s e...

Let P be a simple polygon, and let Q be a set of points in P . We present an almostlinear time algorithm for computing a minimum cover of Q by disks that are contained in P . We then generalize the algorithm, so that it can compute a minimum cover of Q by homothets of any fixed compact convex set O of constant description complexity that are contained in P . This improves previous results of Ka...

a College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, OR 97331, USA b Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada c Department of Geoscience, University of Wisconsin-Madison, 1215 West Dayton Street, Madison, WI 53706, USA d Department of Environmental, Earth & Atmospheric Sciences, University of Massac...

A k-dimensional box is the cartesian product R1 ×R2 × · · · ×Rk where each Ri is a closed interval on the real line. The boxicity of a graph G, denoted as box(G), is the minimum integer k such that G is the intersection graph of a collection of k-dimensional boxes. A unit cube in k-dimensional space or a k-cube is defined as the cartesian product R1 × R2 × · · · × Rk where each Ri is a closed i...

Proof. The first equality follows directly from (1). To see the second equality, first let M be a matching of size ν(G). For each of the |V | − 2|M | vertices v missed by M , add to M an edge covering v. We obtain an edge cover of size |M |+ (|V | − 2|M |) = |V | − |M |. Hence ρ(G) ≤ |V | − ν(G). Second, let F be an edge cover of size ρ(G). For each v ∈ V delete from F , dF (v) − 1 edges incide...

We analyse a newspaper market where media …rms compete for advertising as well as for readership. Firms …rst choose the political position of their newspaper, then set cover prices and advertising tari¤s. We build on the duopoly work in two-sided markets of Gabszewicz, Laussel, and Sonnac (2001, 2002) who show that advertising …nancing can lead to minimum political di¤erentiation. We extend the...