Near-optimal control of a stochastic SICA model with imprecise parameters

An adequate near-optimal control problem for a stochastic SICA (Susceptible-Infected-Chronic-AIDS) compartmental epidemic model for HIV transmission with imprecise parameters is formulated and investigated. We prove some estimates for the state and co-state variables of the stochastic system. The established inequalities are then used to prove a necessary and a sufficient condition for near-optimal control with imprecise parameters. The proofs involve several mathematical and stochastic tools, including the Burkholder-Davis-Gundy inequality.Portuguese Foundation for Science and Technology (FCT) and UIDB/04106/2020 (CIDMA).publishe

A Stochastic Capital-Labour Model with Logistic Growth Function

We propose and study a stochastic capital-labour model with logistic growth function. First, we show that the model has a unique positive global solution. Then, using the Lyapunov analysis method, we obtain conditions for the extinction of the total labour force. Furthermore, we also prove sufficient conditions for their persistence in mean. Finally, we illustrate our theoretical results through numerical simulations.Comment: This is a preprint whose final form is published by Springer Nature Switzerland AG in the book 'Dynamic Control and Optimization

An efficient broadcasting routing protocol WAODV in mobile ad hoc networks

Information broadcasting in wireless network is a necessary building block for cooperative operations. However, the broadcasting causes increases the routing overhead. This paper brings together an array of tools of our adaptive protocol for information broadcasting in MANETs. The proposed protocol in this paper named WAODV (WAIT-AODV). This new adaptive routing discovery protocol for MANETs, lets in nodes to pick out a fantastic motion: both to retransmit receiving request route request (RREQ) messages, to discard, or to wait earlier than making any decision, which dynamically confgures the routing discovery feature to decide a gorgeous motion through the usage of neighbors’ knowledge. Simulations have been conducted to show the effectiveness of the using of techniques adaptive protocol for information broadcasting RREQ packet when integrated into ad hoc on-demand distance vector (AODV) routing protocols for MANET (which is based on simple flooding)

Weighted Generalized Fractional Integration by Parts and the Euler-Lagrange Equation

Integration by parts plays a crucial role in mathematical analysis, e.g., during the proof of necessary optimality conditions in the calculus of variations and optimal control. Motivated by this fact, we construct a new, right-weighted generalized fractional derivative in the Riemann-Liouville sense with its associated integral for the recently introduced weighted generalized fractional derivative with Mittag-Leffler kernel. We rewrite these operators equivalently in effective series, proving some interesting properties relating to the left and the right fractional operators. These results permit us to obtain the corresponding integration by parts formula. With the new general formula, we obtain an appropriate weighted Euler-Lagrange equation for dynamic optimization, extending those existing in the literature. We end with the application of an optimization variational problem to the quantum mechanics framework.Comment: This is a preprint of a paper whose final and definite form is published Open Access in 'Axioms' at [https://doi.org/10.3390/axioms11040178

The power fractional calculus: first definitions and properties with applications to power fractional differential equations

Using the Laplace transform method and the convolution theorem, we introduce new and more general definitions for fractional operators with non-singular kernels, extending well-known concepts existing in the literature. The new operators are based on a generalization of the Mittag–Leffler function, characterized by the presence of a key parameter p. This power parameter p is important to enable researchers to choose an adequate notion of the derivative that properly represents the reality under study, to provide good mathematical models, and to predict future dynamic behaviors. The fundamental properties of the new operators are investigated and rigorously proved. As an application, we solve a Caputo and a Riemann–Liouville fractional differential equation.Fundação para a Ciência e a Tecnologia (FCT), grant number UIDB/04106/2020 (CIDMA).publishe

The influence of magnetic reversed shear in the improvement of quality of confinement in the plasma of Tokamak: Comparison between TEXTOR & ITER

The reversed magnetic shear is the most important factor in the studies of the plasmas of tokamak. In this paper we focus our research, at first stage, on the control of the improved confinement regimes by studying the influence of reversed shear on its quality in the plasma of tokamak and especially in reducing the anomalous transport in TEXT and ITER, then we study the influence of perturbation’s modes in the particles diffusion. In the whole simulations, a comparison between results obtained using ITER and TEXT parameters is carried out.The reversed magnetic shear is the most important factor in the studies of the plasmas of tokamak. In this paper we focus our research, at first stage, on the control of the improved confinement regimes by studying the influence of reversed shear on its quality in the plasma of tokamak and especially in reducing the anomalous transport in TEXT and ITER, then we study the influence of perturbation’s modes in the particles diffusion. In the whole simulations, a comparison between results obtained using ITER and TEXT parameters is carried out

Modelling of Collision in the Plasma Sheath and the Cathode Erosion of Electrical Arc

In order to improve many industrial applications of the plasma sheath and the cathode erosion of electrical arc, the prime objective of this paper is to treat the modelling and simulation of the effects of ions collisionality on the plasma sheath and to determine the collisional dependence of the sheath width and the ion impact energy on the wall using the Runge-Kutta Routrine on the presence or the absence of the term source in the continuity equation . Then , to explain the dependence of the measured erosion rate of the cathode by considering the cathode spot heat balance equation coupled with equation obtained from the sheath and taking into account the physical phenomena such as ion and electron fluxes, radiation, thermal conductivity and evaporation.In order to improve many industrial applications of the plasma sheath and the cathode erosion of electrical arc, the prime objective of this paper is to treat the modelling and simulation of the effects of ions collisionality on the plasma sheath and to determine the collisional dependence of the sheath width and the ion impact energy on the wall using the Runge-Kutta Routrine on the presence or the absence of the term source in the continuity equation . Then , to explain the dependence of the measured erosion rate of the cathode by considering the cathode spot heat balance equation coupled with equation obtained from the sheath and taking into account the physical phenomena such as ion and electron fluxes, radiation, thermal conductivity and evaporation

Comprehensive review of morphological adaptations and conservation strategies of cactiform succulents: A case study of Euphorbia species in arid ecosystems

Cactiform succulents, belonging to the Euphorbia genus, are distinctive species found in the arid and semi-arid ecosystems of Macaronesia and the Arabian Peninsula. Resembling cacti in appearance, they exhibit unique morphological characteristics, such as succulent, green-stemmed structures with ribs, accompanied by a pair of stipular spines. These plants have evolved to thrive in well-draining substrates, including both surface and rocky soils, potentially as an adaptive strategy to combat edaphic drought conditions. Although initially associated solely with arid and desert environments, it is important to note that these cactiform succulents are not exclusively specialized for prolonged dry periods. Rather, they demonstrate morphological adaptations that help them endure arid conditions. The primary objective of this review is to provide an up-to-date synthesis of knowledge concerning cactiform succulents within the Euphorbia genus. It aims to underscore their capacity to flourish in both arid and semi-arid zones, while underscoring the pressing conservation challenges that threaten these plants with degradation and potential extinction. The prevailing climatic conditions, marked by extended and recurrent droughts exacerbated by escalating temperatures, climate fluctuations, and escalating human impact, collectively pose a formidable obstacle to conserving these cactiform succulents and their respective ecosystems. All these threats jeopardize these invaluable natural resources, which hold multifaceted significance spanning environmental, socio-economic, and medicinal domains

Modeling and forecasting of COVID-19 spreading by delayed stochastic differential equations

The novel coronavirus disease (COVID-19) pneumonia has posed a great threat to the world recent months by causing many deaths and enormous economic damage worldwide. The first case of COVID-19 in Morocco was reported on 2 March 2020, and the number of reported cases has increased day by day. In this work, we extend the well-known SIR compartmental model to deterministic and stochastic time-delayed models in order to predict the epidemiological trend of COVID-19 in Morocco and to assess the potential role of multiple preventive measures and strategies imposed by Moroccan authorities. The main features of the work include the well-posedness of the models and conditions under which the COVID-19 may become extinct or persist in the population. Parameter values have been estimated from real data and numerical simulations are presented for forecasting the COVID-19 spreading as well as verification of theoretical results.publishe

A Fully Integrated Electrochemical BioMEMS Fabrication Process for Cytokine Detection: Application for Heart Failure

AbstractIn this present study, a fully integrated BioMEMS was developed using silicon technology to simultaneously detect varying cytokine biomarkers: interleukin-1 (IL-1), interleukin-10 (IL-10), and interleukin-6 (IL-6) using eight gold working microelectrodes (WE). The biomarkers are one of many antigens that are secreted in acute stages of inflammation after left ventricle assisted device (LVAD) implantation for patients suffering from heart failure (HF). The monoclonal antibodies (mAb): anti-human IL-1, IL-10, and IL-6 were immobilized onto gold microelectrodes through functionalization with carboxyl diazonium, respectively. Cyclic voltammetry (CV) was applied during the microelectrode functionalization process to characterize the gold microelectrode surface properties, while electrochemical impedance spectroscopy (EIS) was used to characterize the modified gold microelectrodes. The BioMEMS was highly sensitive towards the three cytokines in a range of 1 pg/mL to 15 pg/mL, which is the window where acute inflammations were observed