To investigate the hole transport across amorphous/crystalline silicon heterojunctions, solar cells with varying band offsets were fabricated using amorphous silicon suboxide films. The suboxides enable good passivation if covered by a doped amorphous silicon layer. Increasing valence band offsets yield rising hole transport barriers and reduced device effciencies. Carrier transport by thermal ...

This paper is concerned with the study of the vibrations of a coupled fluid-solid periodic structure. As the period goes to zero, an asymptotic analysis of the spectrum (i.e., the set of eigenfrequencies) is performed with the help of a new method, the so-called Bloch-wave homogenization method (which is a blend of two-scale convergence and Bloch-wave decomposition). The limit spectrum is made ...

We consider the energy-momentum excitation spectrum of diverse lattice Hamiltonian operators: the generator of the Markov semigroup of Ginzburg-Landau models with Langevin stochastic dynamics, the Hamiltonian of a scalar quantum field theory, and the Hamiltonian associated with the transfer matrix of a classical ferromagnetic spin system at high temperature. The low-lying spectrum consists of a...

A new microspectroscopic technique was applied to the analysis of occluding deposits in xylem elements of Quercus serrata. The production of this substance is believed to be a defense response of the sapwood against fungal infection. An occluding substance about 10 μm across was analyzed by Infrared-Scanning Near-field Optical Microscopy (IR-SNOM), which allows for the measurement of IR spectru...

Power spectrum estimation is one of the important applications in DSP. Basically a spectrum is a relationship typically represented by a plot of the magnitude or relative value of some parameter against frequency. In this Paper Non Parametric Methods are used for power spectrum estimation namely Periodogram Method and Welch Method. Here A Band pass FIR Filter using two different Window Techniqu...

This paper presents a significant modification of our previously proposed speech recognizer’s front-end based on perceptual harmonic cepstral coefficients. The spectrum is split into two frequency bands, which correspond to the harmonic and non-harmonic components. A weighting function, which depends both on the voiced/unvoiced/ transitional classification and on the prominence of harmonic stru...

We consider spectrally-precoded OFDM waveforms for 5G wideband transmission in sub-6GHz band. In this densely packed spectrum, a low out-of-band (OOB) waveform is a critical 5G component to achieve the promised high spectral efficiency. By precoding data symbols before OFDM modulation, it is possible to achieve extremely low out-of-band emission with very sharp spectrum transition enabling an e...

The low transmission power and very large bandwidth used by Ultra-Wide band (UWB) radio systems ,enables them co-exist with other narrow-band systems over the same frequency band without interfering the narrow-band systems. Nevertheless, the interference caused by these narrow-band systems may jam the UWB receiver. Existing narrow-band interference suppression methods for spread spectrum system...

In this study, we determine the fine spectrum of the matrix operator ∆ defined by an upper triangle double band matrix acting on the sequence space c0 with respect to the Goldberg’s classification. As a new development, we give the approximate point spectrum, defect spectrum and compression spectrum of the matrix operator ∆ on c0. AMS subject classifications: 47A10, 47B37

The emerging feature-rich and high-data-rate wireless applications have put increasing demand on radio spectrum. The scarcity of spectrum and the inefficiency in its usage, as caused by the current radio spectrum regulations, necessitate the development of new dynamic spectrum allocation policies to better exploit the existing spectrum. The current spectrum allocation regulations assign specifi...