Metasurfaces could be very beneficial when elaborating solar cells to succeed in balancing between cost and efficiency. Thus, thin absorbers achieving high performance are attainable with the possibility use any material. In this work, a perfect absorber based on tungsten (W) metal-insulator-metal (MIM) metasurface is proposed. The MIM array consists of rectangular double split ring resonator (...

The notion of concurrent signatures was recently introduced by Chen, Kudla and Paterson. In concurrent signature schemes, two entities can produce two signatures that are not binding, until one of the parties releases an extra piece of information (namely the keystone). Subsequently, it was noted that the concurrent signature scheme proposed in the seminal paper cannot provide perfect ambiguity...

We consider generation of a perfect optical vortex by three elements: (i) amplitude-phase element with its transmission being proportional to the Bessel function, (ii) optimal element with the transmission proportional to the sign of the Bessel function, and (3) helical axicon. Maximal intensity of light on the ring is shown to be achieved by using the optimal element. Thickness of the light ri...

Roussel and Rubio proved a lemma which is essential in the proof of the Strong Perfect Graph Theorem. We give a new short proof of the main case of this lemma. In this note, we also give a short proof of Hayward’s decomposition theorem for weakly chordal graphs, relying on a Roussel–Rubio-type lemma. We recall how Roussel–Rubio-type lemmas yield very short proofs of the existence of even pairs ...

We will extend Reed's Semi-Strong Perfect Graph Theorem by proving that unbreakable C 5-free graphs diierent from a C 6 and its complement have unique P 4-structure.

In this paper, for the first time to our knowledge, we investigate the optical bi-stability in a compact parallel array of micro- ring resonators with 5μm radius, induced by optical nonlinearity. Due to the nature of perfect light confinement, resonance and accumulation process in a ring resonator, optical nonlinear effects, even at small optical power of a few milliwatts in this structure are ...

We prove that if $R$ is a commutative Noetherian ring, then every countably generated flat $R$-module quite flat, i.e., direct summand of transfinite extension localizations in countable multiplicative subsets. also show the spectrum cardinality less than $\kappa$, where $\kappa$ an uncountable regular cardinal, modules with generators. This provides alternative proof fact over ring spectrum, a...

Let (R, m) be a local commutative ring. Suppose that m is principal and that m = 0. We give a complete description of the cellular lattice of perfect chain complexes of modules over this ring.