In this paper, we study the antenna orientation problem concerning symmetric connectivity in directional wireless sensor networks. We are given a set of nodes each of which is equipped with one directional antenna with beam-width θ = 2π/3 and is initially assigned a transmission range 1 that yields a connected unit disk graph spanning all nodes. The objective of the problem is to compute an ori...

Despite the development of crystal engineering, it remains a great challenge to predict the crystal structure even for the simplest molecules, and a clear link between molecular and crystal symmetry is missing in general. Here we demonstrate that the two-dimensional (2D) crystallization of heterocirculenes on a Au(111) surface is greatly affected by the molecular symmetry. By means of ultrahigh...

high temperatures are often encountered in almost all of the combustion systems, therefore, thermal radiation heat transfer can influence the droplets heat up rate and consequently their life time. in this paper, the effect of thermal radiation heat transfer is investigated for two cases of directional and spherically symmetric illuminations. the flow and temperature fields insdie and outside o...

in this paper‎, ‎we determine the simple groups $g=ab$‎, ‎where $b$ is isomorphic to $l_{3}(4)$ and $a$ isomorphic to an alternating or a symmetric group on $ngeq5$‎, ‎letters‎.

in this paper‎, ‎we determine the simple groups $g=ab$‎, ‎where $b$ is isomorphic to $l_{3}(4)$ and $a$ isomorphic to an alternating or a symmetric group on $ngeq5$‎, ‎letters‎.

Small-angle neutron scattering (SANS) measurements from thin sections of rock samples such as shales demand as great a scattering vector range as possible because the pores cover a wide range of sizes. The limitation of the scattering vector range for pinhole SANS requires slit-smeared ultra-SANS (USANS) measurements that need to be converted to pinhole geometry. The desmearing algorithm is onl...

We outline here a proof that a certain rational function C n (q; t) which has come to be known as the \q; t-Catalan" is in fact a polynomial with positive integer coeecients. Since C n (q; t) evaluates to the Catalan number at t = q = 1, it has also been an open problem to nd a pair of statistics a; b on the collection D n of Dyck paths of length 2n yielding C n (q; t) = P t a(() q b((). Our pr...