We theoretically demonstrate the population switching of quantum dots (QD’s), modeled as two-level atoms in idealized one-dimensional (1D) and two-dimensional (2D) photonic crystals (PC’s) by self-consistent solution of the Maxwell-Bloch equations. In our semiclassical theory, energy states of the electron are quantized, and electron dynamics is described by the atomic Bloch equation, while ele...

A plate periodically bonded with piezoelectric patches on its surfaces is considered. The differential quadrature element method is used to solve the wave motion equation for the two-dimensional periodic structure. The method is very simple and easy to implement. Based on the method, band structures for in-plane wave propagating in the periodic piezoelectric plate are studied, from which the fr...

Broadband orthogonal frequency division multiplexing (OFDM) communication systems utilizing the low-voltage power supply network are exposed to different types of disturbances, which essentially determine the achievable transmission capacity. Narrow band interference (NBI), that can be caused by switching power supplies as welt as the ingress of short and medium wave radio transmitters located ...

Consciousness has been proposed to emerge from functionally integrated large-scale ensembles of gamma-synchronous neural populations that form and dissolve at a frequency in the theta band. We propose that discrete moments of perceptual experience are implemented by transient gamma-band synchronization of relevant cortical regions, and that disintegration and reintegration of these assemblies i...

In this paper, a novel technique for the design of two-channel Quadrature Mirror Filter (QMF) banks with linear phase in frequency domain is presented. To satisfy the exact reconstruction condition of the filter bank, low-pass prototype filter response in pass-band, transition band and stop band is optimized using unconstrained indirect update optimization method. The objective function is form...

This paper deals with the quality requirements of synthesized sine waves reconstructed through a zeroor firstorder hold for testing purposes, in particular when a switching demodulator is used. In this case, the interest is to have great spectral purity near the carrier rather than in all of the band. We show that the best method to obtain great spectral purity in the frequency band close to th...

In this paper, four-switch inverter fed direct torque control three phase Induction Motor drive is presented. A triangular wave is used as dither signal of minute amplitude (for torque hysteresis band and flux hysteresis band respectively) in the error block. This method minimizes flux and torque ripple in a Four-Switch inverter fed induction motor drive while the dynamic performance is not aff...

This study presents new antenna schemes suitable for cognitive radio communications. The antenna structures consist of a ultra wide band (UWB) sensing antenna, and a frequency reconfigurable communicating antenna both incorporated into the same substrate. Two different techniques to achieve the required frequency agility are proposed. The first one is based on a rotational motion of the radiati...

A scheduling problem that includes different hardware delays experienced by the secondary users (SUs) while switching to different frequency bands in a centralized cognitive radio network (CRN) is formulated. A polynomial-time suboptimal algorithm is proposed to reduce the scheduling problem. The impact of varying switching delay, number offer quencies, and number of SUs is evaluated. The simul...

Abstract Failure of the transformer bushing will cause to be powered down or damaged, affecting safe operation power system. This paper proposes a method using system harmonics as dielectric response excitation source and studies insulation online detection technology based on transient characteristics. The technical scheme structure monitoring characteristics are given. A calculation model sho...