The periodic lambda algebra is a co-Koszul complex of the Steenrod algebra whose homology gives the E2 term for the Adams spectral sequence. Its elements are closely related to periodic homotopy theory, and exhibit periodic properties. In this paper we discuss an algorithm to compute the homology of the periodic lambda algebra, and investigate the algebraic structure for the E2 page of the vn p...

one of the most crucial elements of each country is electricity distribution networks (edn). awareness of accidents in edn could be very important in the conservation and utilization of them. the accurate and periodic inspections can provide a good service to subscribers. the goal of this project is to fabricate a quad rotor, which can do an accurate and a periodic inspection. the design and im...

We introduce a solution based on the source-model technique for periodic structures for the problem of electromagnetic scattering by a two-dimensional photonic bandgap crystal slab illuminated by a transverse-magnetic plane wave. The proposed technique takes advantage of the periodicity of the slab by solving the problem within the unit cell of the periodic structure. The results imply the exis...

We study light transport in ordered, partially ordered, and completely random one-dimensional (1-D) systems. In a periodic structure, there are three types of passbands with different origins. When disorder is introduced to a periodic system, the passbands change differently, depending on their origins. The transmissivity and decay length in the passbands near the band edges decrease drasticall...

This work is concerned with the unique determination of a periodic diffraction grating profile in three dimensions by some scattered electromagnetic fields measured above the grating. In general, it is well known that global uniqueness may not be true when the measurement is only taken for one incident field. Our goal is to completely characterize the global uniqueness properties when the perio...

Periodic structure plays important role with its sensitivity for frequency in microwave communication and optical integrated circuit system [1][2]. Also, in optical fiber communication[3], such periodic structure is used for supporting optical wave to be guided in core of the fiber. In such application, a defect in the structure generally works as a cavity or a waveguide by making use of its hi...

Light trapping is of very high importance for silicon photovoltaics (PV) and especially for thin-film silicon solar cells. In this paper we investigate and compare theoretically the light trapping properties of periodic and stochastic structures having similar geometrical features. The theoretical investigations are based on the actual surface geometry of a scattering structure, characterized b...

in the present paper the linear oscillator in r3 with z =constanthas been considered. the aim is to determine the necessary conditions forthe persistence of periodic solutions under discontinuous perturbations. a newapproach based on a computational method has been used. at the end weapply our method on an example.

A simple model of 1D structure based on a Fibonacci sequence with variable atomic spacings is proposed. The model allows for observation of the continuous transition between periodic and non-periodic diffraction patterns. The diffraction patterns are calculated analytically both using “cut and project” and “average unit cell” method, taking advantage of the physical space properties of the stru...