The Synchronization Behaviors of Coupled Fractional-Order Neuronal Networks under Electromagnetic Radiation

Previous studies on the synchronization behaviors of neuronal networks were constructed by integer-order neuronal models. In contrast, this paper proposes that the above topics of symmetrical neuronal networks are constructed by fractional-order Hindmarsh–Rose (HR) models under electromagnetic radiation. They are then investigated numerically. From the research results, several novel phenomena and conclusions can be drawn. First, for the two symmetrical coupled neuronal models, the synchronization degree is influenced by the fractional-order q and the feedback gain parameter k1. In addition, the fractional-order or the parameter k1 can induce the synchronization transitions of bursting synchronization, perfect synchronization and phase synchronization. For perfect synchronization, the synchronization transitions of chaotic synchronization and periodic synchronization induced by q or parameter k1 are also observed. In particular, when the fractional-order is small, such as 0.6, the synchronization transitions are more complex. Then, for a symmetrical ring neuronal network under electromagnetic radiation, with the change in the memory-conductance parameter β of the electromagnetic radiation, k1 and q, compared with the fractional-order HR model’s ring neuronal network without electromagnetic radiation, the synchronization behaviors are more complex. According to the simulation results, the influence of k1 and q can be summarized into three cases: β>0.02, −0.06<β<0.02 and β<−0.06. The influence rules and some interesting phenomena are investigated.

Analysis of some physiological indicators in tomato plants to characterize the effects of additional lighting with blue, red and white LEDs

The use of light-emitting diodes (LEDs) in vegetable species is one of the technological procedures applied to improve the spectral composition of light in protected areas, as well as to stimulate plant growth, obtaining high values of production and increasing resistance to conditions of culture. The biological material represented by tomato seedlings, from varieties with nutritional value and with high ecological plasticity, was studied in terms of characterizing the effects of applying the treatment using light fields emitted by blue, red and white LEDs, by analysis physiological parameters, such as: photosynthesis intensity (μmols CO2m-2s -1), transpiration intensity (mmoles H2O m-2s -1), stomatal conductance (mols H2O m-2s -1) and intercellular carbon dioxide (mmol CO2 mol-1 air). In this study, the estimation of the amount of total chlorophyll (mg m-2), was also investigated. The determinations of the physiological parameters were performed in 3 series, and the recorded results were statistically analysed, by expressing the significance of the differences between the control and the studied tomato varieties being studied. Thus, after the treatment period, applied in 23 days (Series II), with monochrome LEDs, at the level of the stomatal conductance parameter, statistically assured values were registered for the plants in the ‘L-75’ line exposed to White LED and for those in the ‘L-76’ line exposed to the Blue LED. The analysis of the results from the investigation of the physiological parameters at the level of the leaves from the experimental samples indicated that after 35 days (Series III), from the application of the treatments of 30 minutes/day, with White LED light, they ensured the plants tomatoes from the ‘L-76’ line, distinctly significantly positive values, compared to those of the control plants, at the intensity of photosynthesis and the internal concentration of CO2.

The Synchronization and Synchronization Transition of Coupled Fractional-order Neuronal Networks

Different from the previous researches on the synchronization and synchronization transition of neuronal networks constructed by integer-order neuronal models, the synchronization and synchronization transition of fractional-order neuronal network are investigated in this paper. The fractional-order ring neuronal network constructed by fractional-order HindmarshRose (HR) neuronal models without electromagnetic radiation are proposed, and it’s synchronization behaviors are investigated numerically. The synchronization behaviors of two coupled fractional-order neuronal models and ring neuronal network under electromagnetic radiation are studied numerically. By research results, several novel phenomena and conclusions can be drawn. First, for the fractional-order HR model’s ring neuronal network without electromagnetic radiation, if the fractional-order q is changed, the threshold of the coupling strength when the network is in perfect synchronization will change. Furthermore, the change of fractional-order can induce the transition of periodic synchronization and chaotic synchronization. Second, for the two coupled neurons under electromagnetic radiation, the synchronization degree is influenced by fractional-order and the feedback gain parameter k1 . In addition, the fractional-order and parameter k1 can induce the synchronization transition of bursting synchronization, perfect synchronization and phase synchronization. For the perfect synchronization, the synchronization transition of chaotic synchronization and periodic synchronization induced by q and parameter k1 is also observed. Especially, When the fractionalorder is small, like 0.6, the synchronization behavior will be more complex. Third, for the ring neuronal network under electromagnetic radiation, with the change of memory-conductance parameter β, parameter k1 and fractional-order q of electromagnetic radiation, the synchronization behaviors are different. When β > 0.02 , the synchronization will be strengthened with the decreasing of fractional-order. The parameter k1 can induce the synchronization transition of perfect periodic10 synchronization, perfect periodic-7 synchronization, perfect periodic-5 synchronization and perfect periodic4 synchronization. It is hard for the system to synchronize and q has little effect on the synchronization when −0.06 < β < 0.02 . When β < −0.06 , the network moves directly from asynchronization to perfect synchronization, and the synchronization factor goes from 0.1 to 1 with the small change of fractional-order. Larger the factional-order is, larger the range of synchronization is. The synchronization degree increases with the increasing of k1.

NUMERICAL INVESTIGATION OF SIGNAL AMPLIFICATION VIA VIBRATIONAL RESONANCE IN CHUA'S CIRCUIT

In this paper, we numerically investigated the occurrence of Vibrational Resonance in a modified Chua's oscillator with a smooth nonlinearity, described by a cubic polynomial. Response curves generated from the numerical simulation at the low frequency reveal that the system's response amplitude could be controlled by modulating the conductance parameter of the Chua's circuit, rather modulating the parameters of the fast-periodic force. Modulating the frequency of the fast-periodic force slightly reduces the response amplitude; shifts the peak point to a higher value of the amplitude of the fast-periodic force by widening the resonance curves. Within certain parameter regime of the high frequency (Ω >100ω), the system's response gets saturated, and further increase does not affect its amplitude.

Image Restoration using a Nonlinear Second-order Parabolic PDE-based Scheme

A novel anisotropic diffusion-based image denoising and restoration approach is proposed in this paper. A variational model for image restoration is introduced first, then the corresponding Euler-Lagrange equation being determined. A nonlinear parabolic PDE model is then obtained from this equation. It is based on a novel edge-stopping function and conductance parameter. A serious mathematical treatment is performed on this second-order anisotropic diffusion scheme, its well-possedness being investigated. Then, a consistent explicit numerical approximation scheme based on the finite difference method is developed for the proposed PDE model.

Combined Energy and Exergy Analysis of a Nonisothermal Fin Array With Non-Boussinésq Variable Property Fluid

To transport the energy efficiently without much dissipation, first and second law analyses of mixed convection heat transport from an array of nonisothermal rectangular vertical plate-finned heat sink are made using purely computational fluid dynamics (CFD) analysis on the governing equations. Report provides the dependence of Nusselt number, entropy production, pumping power ratio (PPR), and flow bypass factor (BF) on the inlet velocity, fin conductance parameter, thermal Grashof number (Gr), dimensionless clearance (C*), and dimensionless fin spacing (S*). Total nondimensional entropy production is found to decrease continuously with clearances for all fin spacings, except at the lowest fin spacing involving lowest Gr (= 1.8 × 105). On the other hand, at higher inlet velocities, Nusselt number indicates an optimum value with clearances. Optimum Nusselt number is found to observe in a range of S* = 0.2–0.3 for all Gr. For smaller fin spacing, PPR is noticeably higher, but at the optimum value of fin spacing, PPR reduces roughly by an order of magnitude. Interestingly, flow bypass is remarkably lower at the optimum clearance. Finally, correlation of friction factor, PPR, and entropy generation is presented.

Laminar Fully Developed Flow and Heat Transfer in Triangular Plate-Fin Ducts

This paper presents a numerical investigation of fully developed flow and heat transfer in triangular cross section plate-fin ducts encountered in compact heat exchangers. Heat conduction in the fin and convection in the fluid are analyzed simultaneously as a conjugate problem. Overall and local results are presented for representative values of the duct aspect ratio and a fin conductance parameter.

Analysis of Laminar Heat Transfer in Internally Finned Tubes with Uniform Outside Wall Temperature

An analysis is presented for fully developed laminar convective heat transfer in tubes with internal longitudinal fins and uniform outside wall temperature. The governing momentum and energy equations were solved numerically, with the influence of fin conductance accounted for by a single parameter. The distributions of fin temperature, fluid temperature and local heat flux (both at the fin and unfinned surfaces) are presented. These are shown to be strongly dependent on finned tube geometry and, in some cases, on the fin conductance parameter as well. Based on average heat transfer per unit area, the various fins proved more effective than the unfinned surfaces. Values for overall Nusselt number indicated significant heat transfer enhancement over smooth tube conditions.