Using the characteristic property of chordal graphs that they are the intersection graphs of subtrees of a tree, Erich Prisner showed that every chordal graph admits an eccentricity 2approximating spanning tree. That is, every chordal graph G has a spanning tree T such that eccT (v) − eccG(v) ≤ 2 for every vertex v, where eccG(v) (eccT (v)) is the eccentricity of a vertex v in G (in T , respect...

When illusory self-motion is induced in a stationary observer by optic flow, the perceived distance traveled is generally overestimated relative to the distance of a remembered target (Redlick, Harris, & Jenkin, 2001): subjects feel they have gone further than the simulated distance and indicate that they have arrived at a target's previously seen location too early. In this article we assess h...

PURPOSE The spatial distribution of macular pigment is generally assumed to monotonously decrease to very low values in the periphery. However, there are indications that this picture may be too simple. The purpose of this study was to examine the spatial distribution of the macular pigment optical density. METHODS Fundus reflectance and autofluorescence maps at 488 and 514 nm Argon laser wav...

The serial pattern found for conjunction visual-search tasks has been attributed to covert attentional shifts, even though the possible contributions of target location have not been considered. To investigate the effect of target location on orientation x color conjunction searches, the target's duration and its position in the display were manipulated. The display was present either until obs...

Observations of Keplerian disks of masers in NCG 4258 and other Seyfert galaxies can be used to obtain geometric distance estimates and derive the Hubble constant. The ultimate precision of such measurements could be limited by uncertainties in the disk geometry. Using a time-dependent linear theory model, we study the evolution of a thin initially eccentric disk under conditions appropriate to...

Early migration damped Neptune's eccentricity. Here, we assume that the value was much smaller than observed today, and show closest flyby of ∼0.1 M⊙ star over ∼4.5 Gyr in field, at a distance ∼103 au would explain eccentricity today.

let $d$ be a digraph with skew-adjacency matrix $s(d)$‎. ‎the skew‎ ‎energy of $d$ is defined as the sum of the norms of all‎ ‎eigenvalues of $s(d)$‎. ‎two digraphs are said to be skew‎ ‎equienergetic if their skew energies are equal‎. ‎we establish an‎ ‎expression for the characteristic polynomial of the skew‎ ‎adjacency matrix of the join of two digraphs‎, ‎and for the‎ ‎respective skew energ...

Energy-constrained wireless sensor network (WSN) has attained considerable research attention in recent years and requires robust and energy efficient routing protocols for communication in fading environments to minimise the energy consumption.To Mitigate the Fading Effect in Wireless Channel ,MultiInput Multi Output(MIMO)Scheme is Utilized for Wireless Sensor Network. This Paper proposed a Cl...