Adaptive noise-reducing anisotropic diffusion filter

In image processing and computer vision, the denoising process is an important step before several processing tasks. This paper presents a new adaptive noise-reducing anisotropic diffusion (ANRAD) method to improve the image quality, which can be considered as a modified version of a speckle-reducing anisotropic diffusion (SRAD) filter. The SRAD works very well for monochrome images with speckle noise. However, in the case of images corrupted with other types of noise, it cannot provide optimal image quality due to the inaccurate noise model. The ANRAD method introduces an automatic RGB noise model estimator in a partial differential equation system similar to the SRAD diffusion, which estimates at each iteration an upper bound of the real noise level function by fitting a lower envelope to the standard deviations of pre-segment image variances. Compared to the conventional SRAD filter, the proposed filter has the advantage of being adapted to the color noise produced by today’s CCD digital camera. The simulation results show that the ANRAD filter can reduce the noise while preserving image edges and fine details very well. Also, it is favorably compared to the fast non-local means filter, showing an improvement in the quality of the restored image. A quantitative comparison measure is given by the parameters like the mean structural similarity index and the peak signal-to-noise ratio.     

Effects of a magnetic field environment on quantum cloning of qubits

No cloning distinguishes the quantum cryptography. Buzek and Hillery have developed a universal quantum cloning machine that allows providing two copies of an arbitrary qubit state with the same accuracy independently of the input-state. The fidelity has been used as a criterion to characterize the cloning. It was found that this parameter can achieve 0.85 for special subsets of quantum states, i.e, equatorial qubits. In the present paper, we investigate the effects of a magnetic field environment as a perturbation of the cloning process. The quantum copying machines studied consist of UQCM-BH and UQCM-PC. Results have been discussed using both the fidelity and the relative entropy. Much attention has been paid to the magnetic field-related decoherence of ancillary qubits before preparation. An attempt to explain the impact of this decoherence on the performance of copying machines will be presented.     

Nanoarchitectonics of Ba0.97La0.02Ti1-xNb4x/5O3 (x = 0.00 and 0.10) polycrystalline compounds with electrical and optical properties

Journal of Materials Science: Materials in Electronics - A lead-free solid solution, of a composition Ba0.97La0.02Ti1-xNb4x/5O3 (for x?=?0.00 and 0.10) (noted BLT, BLT0.9Nb0.08), was...     

Event-driven simulations of nonlinear integrate-and-fire neurons

Event-driven strategies have been used to simulate spiking neural networks exactly. Previous work is limited to linear integrate-and-fire neurons. In this note, we extend event-driven schemes to a class of nonlinear integrate-and-fire models. Results are presented for the quadratic integrate-and-fire model with instantaneous or exponential synaptic currents. Extensions to conductance-based currents and exponential integrate-and-fire neurons are discussed.     

Structural,double Jonscher response and non-Debye-type relaxor behavior of Ba0.75Sr0.25Ti0.9Zn0.2O3 ceramic

A new perovskite Ba_0.75Sr_0.25Ti_0.9Zn_0.2O₃ (BSTZO) was synthesized via Molten Salt route. The Rietveld analysis of the X-ray pattern at room temperature indicated a tetragonal structure (P4mm) of the BSTZO ceramic. The conduction process and electrical behavior of the BSTZO ceramic were examined in relation to frequency and temperature. The frequency dependence of conductivity spectra follow double Jonscher law. The latter side was described using a both theoretical conduction models assigned to the Correlated Barrier Hopping model at low temperatures and Non-overlapping Small Polaron Tunneling mechanism at high temperatures. Based on the scaling model, the data merged into a unique master curve, which affirms the validity of the Time -Temperature Superposition Principle. The impedance graph investigations showed that the relaxation in BSTZO is a non-Debye process. The dielectric response confirmed the dominance of the Maxwell–Wagner effect in conduction phenomenon. In addition, the dielectric characteristics exhibited a colossal permittivity, which supports the prospective use of the BSTZO ceramic in electronic devices. In the thermal study, the relaxation processes observed by electrical conductivity, impedance, and modulus are associated with oxygen vacancies.

     

A numerical study of the scalar field in turbulent round jet with co-flowing stream

The influence of co-flow on a turbulent binary gas mixing round jet is numerically studied using a first and a second order turbulence closure models. The objective of the study is to obtain a better understanding of the flow structure and mixing process in turbulent variable-density jets. Comparisons between recently published experimental results and mean mixture fraction, the scalar turbulent fluctuation, and the jet spreading rate, feature reasonably good agreements. It is mainly shown that the co-flow reduces the jet spreading rate, but on the otherhand increases the mixing efficiency.An erratum to this article can be found at     

Nanoarchitectonics of Niobium-Doped,Lead-Free BLT (Ba0.97La0.02Ti0.98Nb0.016O3) for Electrical Properties with Unusual d.c Bias Voltage Independence

Polycrystalline sample of Ba_0.97La_0.02Ti_0.98Nb_0.016O₃ (distinguished as BLTi_0.98Nb_0.016) has been prepared through Molten-Salt-Flux reaction route. The XRD, surface morphology, absorption spectra, impedance, and dielectric behaviors were employed to typify the prepared polycrystalline ceramic. The XRD analysis reflects that obtained perovskite having the pure-tetragonal structure with space group P4/mmm. As of the absorption spectra, the optical band gap (Eg), Urbach energy (Eu), and refractive index values have designed. The electrical properties of synthesized compound have been inspected via complex impedance spectroscopy vs. frequency (f) (10² Hz–10⁶ Hz) within the d.c-bias voltage range [0.5 V–5 V]. The fitting of the Nyquist plot exposes that both intra- and intra grains contribute to relaxation and the grain limits are more resistive and capacitive than the grains. Modulus analysis confirms that relaxation in our sample is of non-Debye nature and d.c-bias voltages dependent. Depending on the frequency, the change of ε′ can be discussed founded on the principle of interfacial polarization of the Maxwell–Wagner category. BLTi_0.98Nb_0.016 shows notable frequency independent relative studied properties, it is a potential candidate for devices.

     

Diffuse Phase Transition and Dielectric Tunability of Ba0.97La0.02TiO3 Relaxor Ferroelectric Ceramic

Journal of Inorganic and Organometallic Polymers and Materials - Lead-free La0.02Ba0.97TiO3 (2LBT) ceramic was elaborated via the molten-salt method characterized by XRD and Raman spectroscopy....