Global Stability Analysis of Healthy Situation for a Coupled Model of Healthy and Cancerous Cells Dynamics in Acute Myeloid Leukemia

In this paper we aim to study the global stability of a coupled model of healthy and cancerous cells dynamics in healthy situation of Acute Myeloid Leukemia. We also clarify the effect of interconnection between healthy and cancerous cells dynamics on the global stability The interconnected model is obtained by transforming the PDE-based model into a nonlinear distributed delay system. Using Lyapunov approach, we derive necessary and sufficient conditions for global stability for a selected equilibrium point of particular interest (healthy situation). Simulations are conducted to illustrate the obtained results

Dynamical Behavior of Biological Healthy Steady State in Leukemia Using a New Leukemic & Healthy Stem Cells Cohabitation Model with Distributed Delay

Acute Myeloid Leukemia (AML) treatment protocol from clinical point of view, aims to maintain a normal amount of healthy cells and to eradicate all malignant cells. This particular objective is biologically qualified as a positive healthy situation. In this paper, we give sufficient and necessary conditions for the global stability of such a healthy situation. To this end, we first propose a new distributed delay model of AML. The latter is an improvement of an existing delayed coupled model describing the dynamics of hematopoesis stem cells in AML. We modify the PDEs equations and transform them into a set of distributed delay equations. The proposed model is more suitable for biological phenomena than constant delay models as the proliferation time differs from a cell type to another. Furthermore in the proposed model, we consider the sub-population of cells that have lost their capacity of self-renewal and became progenitors. In second, we derive sufficient and necessary conditions for the global stability of healthy steady state. For this, the positivity of the obtained model and sequences of functions theory are used to construct new Lyapunov function candidates. Finally, we conduct numerical simulations to show that the obtained results complete and generalize those published in the literature

Power management and control strategies for off-grid hybrid power systems with renewable energies and storage

This document is the Accepted Manuscript of the following article: Belkacem Belabbas, Tayeb Allaoui, Mohamed Tadjine, and Mouloud Denai, 'Power management and control strategies for off-grid hybrid power systems with renewable energies and storage', Energy Systems, September 2017. Under embargo. Embargo end date: 19 September 2018. The final publication is available at Springer via https://doi.org/10.1007/s12667-017-0251-y.This paper presents a simulation study of standalone hybrid Distributed Generation Systems (DGS) with Battery Energy Storage System (BESS). The DGS consists of Photovoltaic (PV) panels as Renewable Power Source (RPS), a Diesel Generator (DG) for power buck-up and a BESS to accommodate the surplus of energy, which may be employed in times of poor PV generation. While off-grid DGS represent an efficient and cost-effective energy supply solution particularly to rural and remote areas, fluctuations in voltage and frequency due to load variations, weather conditions (temperature, irradiation) and transmission line short-circuits are major challenges. The paper suggests a hierarchical Power Management (PM) and controller structure to improve the reliability and efficiency of the hybrid DGS. The first layer of the overall control scheme includes a Fuzzy Logic Controller (FLC) to adjust the voltage and frequency at the Point of Common Coupling (PCC) and a Clamping Bridge Circuit (CBC) which regulates the DC bus voltage. A maximum power point tracking (MPPT) controller based on FLC is designed to extract the optimum power from the PV. The second control layer coordinates among PV, DG and BESS to ensure reliable and efficient power supply to the load. MATLAB Simulink is used to implement the overall model of the off-grid DGS and to test the performance of the proposed control scheme which is evaluated in a series of simulations scenarios. The results demonstrated the good performance of the proposed control scheme and effective coordination between the DGS for all the simulation scenarios considered.Peer reviewedFinal Accepted Versio

Ageing of out-of-equilibrium nanoalloys by a kinetic mean-field approach

International audienceThis study describes the ageing of bimetallic nanoparticles using a kinetic mean-field method which provides the time evolution of the concentration for each site. We consider the cuboctahedron of 309 atoms in the Cu–Ag system, which is a prototype of systems with a strong tendency to phase separate. Starting from an initial homogenous configuration, we investigate the evolution towards the equilibrium configuration at different temperatures. Surprisingly, at low temperature, the kinetics exhibits a first transition towards an onion-like configuration followed by a second transition towards the equilibrium core–shell configuration. An analysis of the kinetics of the formation and then of the dissolution of the onion-like structure allows us to identify the main paths of the kinetic process

Fuzzy logic controller for a pneumatic artificial muscle robot based on sliding mode control

Fuzzy Logic Control (FLC) has been successfully established in control systems engineering in the recent years, in other hand, Sliding Mode Control (SMC) is an active area in control research. The combination of this tow fields called Fuzzy Sliding Mode Control (FSMC) techniques to exploit the superior sides of these two controllers have drawn the attention of the scientific community. In this work, we proposed fuzzy logic controller based on the sliding mode theory to control the robot arm actuated by the pneumatics artificial muscles. Using bang-bang motion generation law, the objective of the control is the position and the velocity tracking by the robot. Simulations results demonstrate the feasibility and the advantages of our proposed research work

A New Quantum-computing-based Algorithm for Robotic Arms ‎and Rigid Bodies

Quantum computing model of robotic arm orientation is presented. Spherical and vector coordinates, a homogenous rotation matrix, Pauli gates and quantum rotation operators are used to formulate the orientation model and establish a new algorithm. The quantum algorithm uses a single qubit to compute orientation and has the advantage of operation reversibility. This was validated for a SCARA robot and a five-joints articulated robotic arm. The obtained results show the effectiveness of the proposed methodology

Optimization of a proportional derivative (PD) fuzzy controller using the particle swarm optimization (PSO) technique for a 3DOF robot manipulator

This paper deals with the optimization of a proportional derivative (PD) fuzzy controller using the particle swarm optimization (PSO) technique. More precisely, we conduct a comparative study to access the performance of the PD fuzzy controller by optimizing its gain and its structural parameters separately, the optimization will done offline; thus leading two distinct fuzzy controllers. The two controllers are applied to control a 3DOF PUMA560 robot manipulator. The structure of the proposed controller is composed of a symmetric fuzzy set ranging between [-1 1] with triangular symmetric membership function. It is shown that the fuzzy controller with optimized gain performs better, compared to the one with optimized parameters, in ideal conditions without noise. Additionally, it is easy and simple to program and implement since there are only a few gain variables to optimize. Also, the execution time is much lower than that required by the optimized parameter fuzzy controller. On the other hand, the optimized parameter controller performs better in the presence of noise in some joints

Backstepping/DTC control of a double star synchronous machine drive

Direct torque control (DTC) allows for very high quality torque control without a need for current controllers tuning or using coordinate transformation. However, barge torque ripples arise as well as inconstant inverter switching frequency due to the hysteresis of comparators. This paper present a backstepping/DTC control based on the space vector modulation (SVPWM) for double star synchronous machine (DSSM) to reduce the torque, flux, current and speed pulsations during steady state. By the coordinate transformation the DSSM models are presented in view of control. Then a conventional DTC is developed to get a decoupled system and a PI controller is designed to control the speed. To improve the static and dynamic control performance of the DSSM, the speed controller is designed using a backstepping/DTC procedure in conjunction with SVPWM. Simulation results with the conventional DTC and proposed backstepping/DTC are presented and compared. Results show the effectiveness and the robustness of the approach proposed