The electromagnetically induced transparency (EIT) phenomenon in a four level atomic system with tripod configuration is studied. The results show that this configuration is equivalent to the combination of two single three-level Λ configurations, which, under certain conditions, results in the so-called double-EIT (DEIT) phenomenon. The properties of the double transparency windows for DEIT ar...

For automatic and recursive graphs, we investigate the following problems: (A) existence of a Hamiltonian path and existence of an infinite path in a tree (B) existence of an Euler path, bounding the number of ends, and bounding the number of infinite branches in a tree (C) existence of an infinite clique and an infinite version of set cover The complexity of these problems is determined for au...

At CT-RSA 2009, a new principle to secure RSA (and modular/group exponentiation) against fault-analysis has been introduced by Rivain. The idea is to perform a so-called double exponentiation to compute a pair (md,mφ(N)−d) and then check that the output pair satisfies the consistency relation: m ·mφ(N)−d ≡ 1 mod N . The author then proposed an efficient heuristic to derive an addition chain for...

We construct orthogonal double covers of Kn,n by Pm+1 ∪∗ Sn−m, where n and m are integers, 2 ≤ m ≤ 10, m ≤ n and Pm+1 ∪∗ Sn−m is a tree obtained from the path Pm+1 with m edges and a star Sn−m with n − m edges by identifying an end-vertex of Pm+1 with the center of Sn−m.

In a recent paper [9], the authors introduced the extended Q-bipartite double of an almost dual bipartite cometric association scheme. Since the association schemes arising from linked systems of symmetric designs are almost dual bipartite, this gives rise to a new infinite family of 4-class cometric schemes which are both Q-bipartite and Q-antipodal. These schemes, the schemes arising from lin...

Abstract Let H be a graph on n vertices and G a collection of n subgraphs of H, one for each vertex. Then G is an orthogonal double cover (ODC) of H if every edge of H occurs in exactly two members of G and any two members of G share exactly an edge whenever the corresponding vertices are adjacent in H. If all subgraphs in G are isomorphic to a given spanning subgraph G, then G is said to be an...

We analyzed simultaneous observation data with ground-based synthetic aperture radar (GB-SAR) and airborne SAR (PiSAR) over a flood test site at which a simple house was constructed in a field. The PiSAR σ◦ under flood condition was 0.9 to 3.4 dB higher than that under nonflood condition. GB-SAR gives high spatial resolution as we could identify a single scattering component and a double bounce...

The large-N behavior of Yang-Mills and generalized Yang-Mills theories in the double-scaling limit is investigated. By the double-scaling limit, it is meant that the area of the manifold on which the theory is defined, is itself a function of N . It is shown that phase transitions of different orders occur, depending on the functional dependence of the area on N . The finite-size scalings of th...

We find arbitrarily large finite sets S of points in general position in the plane with the following property. If the points of S are equitably 2-colored (i.e., the sizes of the two color classes differ by at most one), then there is a polygonal line consisting of straight-line segments with endpoints in S, which is Hamiltonian, non-crossing, and alternating (i.e., each point of S is visited e...

We present a self-contained proof that the number of diameter pairs among n points in Euclidean 3-space is at most 2n − 2. The proof avoids the ball polytopes used in the original proofs by Grünbaum, Heppes and Straszewicz. As a corollary we obtain that any three-dimensional diameter graph can be embedded in the projective plane. Let S be a set of n points of diameter D in Rd. Define the diamet...