Application of genetic algorithm with a novel adaptive scheme for the identification of induction machine parameters

This work presents a powerful application of genetic algorithm (GA) for the identification of Park's model electric parameters of an induction machine. Such a model is used in control techniques for variable speed drives. GA is considered as the most recent product of the artificial intelligence techniques. By its evolutionary character, it solves efficient electrical engineering problems despite its relative slowness in its standard form. Such shortcoming has been dealt with by incorporating a novel adaptive scheme. The suggested adaptive GA aims at accurately solving a nonlinear fitting optimization problem within a reduced computing time. The yielded solution of parameters produces, according to the machine model, the closest possible curves to those of the references. Finally, for the purpose of validation, the obtained machine performances of the adaptive GA method are compared with both those of references and those of a near-least-square-error estimator using experimental variable load measurements.     

Boundary Exponential Stabilization for a Class of Coupled Reaction-Diffusion Equations with State Delay

A class of coupled parabolic PDEs with time delay is considered. We treat the problem of boundary exponential stabilization where the goal is to present a state feedback law with actuation on only one end of the domain which provide the exponential stability of the closed-loop system. We consider both the Dirichlet and Neumann boundary conditions. The corresponding proposed control law is given in explicit form. Numerical simulations are carried out to show the effectiveness of the obtained results.

     

GIS-based landslide susceptibility mapping in the Safi region,West Morocco

Bulletin of Engineering Geology and the Environment - This study aims to establish susceptibility maps for the Moroccan Safi region, which is affected by karstification processes. This process is...     

Combined frequency-prediction error identification approach for Wiener systems with backlash and backlash-inverse operators

Wiener systems identification is studied in the presence of possibly infinite-order linear dynamics and memory nonlinear operators of backlash and backlash-inverse types. The latter is laterally bordered with polynomial lines of arbitrary-shape. It turns out that the borders are allowed to be noninvertible and crossing making possible to account, within a unified theoretical framework, for memory and memoryless nonlinearities. Moreover, the prior knowledge of the nonlinearity type, being backlash or backlash-inverse or memoryless, is not required. Using sine excitations, and getting benefit from model plurality, the initial complex identification problem is made equivalent to two tractable (though still nonlinear) prediction-error problems. These are coped with using linear and nonlinear least squares estimators which all are shown to be consistent.     

Large Eddy Simulation of a Turbulent Flow in a Differentially Heated Cavity with Rayleigh Numbers up to 1011： Part I,Numerical Methods

Large Eddy Simulations of the anisothermal turbulent flows has been used in the context of interaction problems thermal fluid, structure. In this context, the aim of this work lies not only in identifying the various elements that may underestimate the temperature fluctuations at the interface fluid-solid but also the introduction of the models capable of reproducing the physical setting Thurs. At first, the choice of convection scheme 〈optimizing〉 the scalar transport has led to the adoption of an upwind scheme of theorem 2 order. The use of models with conventional walls showed weaknesses in the estimation of temperature fluctuations bet stalls in the case of boundary layers attached. This work presents a numerical validation of LES-WALE model using the results of the K-epsilon model, this study is based on 3D numerical simulation using FLUENT code calculates to determine the longitudinal velocity, the thermal fields for the configuration the and speed vectors （U, V, W） for configuration in the plane of the recirculation zones for the case of different values of flow Rayleigh. Therefore, the results have good agreement with those of k-epsilon model, as they show the difference between the cases of flows.     

Effect of season on contractile and metabolic properties of desert camel muscle (Camelus dromedarius)

Thirty fattened one humped desert camels were used to examine the effect of season on contractile and metabolic properties of Longissimus thoracis (LT) muscle. Ten camels were slaughtered according to seasons of the year (winter, summer and autumn). Season significantly influenced muscle chemical composition, ultimate pH (pHu) and color. Activities of metabolic enzymes were higher during autumn season compared to summer and winter for phosphofructokinase (+ 64% compared to both seasons) and for isocitrate dehydrogenase (+ 35% and + 145% in autumn vs. summer and winter, respectively). Quantification of muscle myosin heavy chain isoforms by SDS-PAGE electrophoresis showed only presence of type I and type IIa MyHC in camel muscle and indicated high proportion in winter for type I and in autumn for type IIa with respect to other seasons. Several correlations between different MyHC proportions and enzyme activities were reported. These findings indicated that muscle characteristics in camels are influenced by season.     

Bone mineral recovery after parathyroidectomy in patients with primary and renal hyperparathyroidism

Patients with hyperparathyroidism (HPT) generally display reduced bone mass due to excessive PTH activity. The effect of parathyroidectomy on bone mass changes in different types of HPT, however, is not well understood. Bone mineral density (BMD) was measured in the distal radius, total body, femoral neck, and lumbar spine by dual energy x-ray absorptiometry in four groups of patients with different hyperparathyroid conditions: primary symptomatic HPT (n = 54), primary asymptomatic (mild) HPT (n = 24), HPT associated with hemodialysis (n = 20), and HPT associated with renal transplant (n = 30). Subsets of patients with primary symptomatic HPT (n = 52), HPT associated with hemodialysis (n = 19), and HPT associated with renal transplant (n = 15) underwent parathyroidectomy, and bone density was measured longitudinally for 3 yr. Patients with primary asymptomatic (mild) HPT did not undergo surgery and were followed prospectively. Before surgery, all groups showed a greater reduction of bone mineral density in cortical bone (distal radius) than in predominantly trabecular bone (lumbar spine). In primary symptomatic HPT, the BMD z-score of the distal radius was -1.80 +/- 0.21 (+/-SEM), and the corresponding figures for the total body, femoral neck, and lumbar spine were -0.60 +/- 0.15, -0.54 +/- 0.14, and -0.53 +/- 0.18 compared with those of an age- and sex-matched reference group. In renal HPT BMD z-scores were -2.51 +/- 0.38 (hemodialysis patients) and -2.83 +/- 0.43 (renal transplant patients) for the distal radius and between -0.81 and -1.46 for the other measured sites. After parathyroidectomy, BMD increased by 1-8% at all sites in patients with primary symptomatic HPT and HPT associated with renal transplant. The largest increase in bone mass was observed in patients with HPT associated with hemodialysis, in whom the improvement amounted to 7-23%. In patients with primary HPT and HPT associated with hemodialysis, this increase in bone density resulted in virtual recovery from their preoperative bone loss. The majority of patients with asymptomatic primary HPT disease (n = 21) maintained their bone density during the follow-up period and have not shown evidence of increases in serum calcium or PTH levels, but three patients followed conservatively underwent parathyroidectomy due to progressive deterioration of BMD. We conclude that, regardless of the etiology, a large proportion of HPT patients show reduced bone density. In patients with primary symptomatic HPT and patients with HPT associated with hemodialysis, bone density increases after parathyroidectomy to an extent that largely restores the preoperative bone loss. However, no anabolic effect of parathyroidectomy on bone mass was observed in patients with HPT associated with renal transplant, probably because of their immunosuppressive therapy.     

Evidence for Nanostructures and Filaments in HTSC From the Electrical Transport Measurements

Recent experimental evidence for the presence of nanostructures (stripe-like features or nanodomains) in HTSC, implies that the flow of the transport current through these materials could occur through quasi-1D filaments, and consequently HTSC materials could behave like a glass with their properties governed by a 2D network of superconducting and normal filaments. We investigated the resistive transport properties of HTSC (YBCO and TBCCO) and their dependence on time, in the normal and the superconducting states.     

Effect of Nickel Doping on the Magnetotransport Properties of?Sm0.55Sr0.45MnO3 Manganites

We studied the effects of nickel (Ni) doping on the magneto-transport properties of Sm_0.55Sr_0.45MnO₃ manganites near the metal-insulator transition. Various concentrations of Ni-doped Sm_0.55Sr_0.45MnO₃ samples up to 10% were prepared (Ni was partially substituted at the Mn-site). The temperature dependence of resistivity and magnetoresistance were measured as a function of Ni concentrations at various applied magnetic fields. We observed a nonlinear reduction of the metal-insulator transition temperature (MIT) with increasing concentration of Ni, 5% of Ni was sufficient to completely suppress the insulator-metal transition. Moreover, we observed dramatic increases of the resistance of the doped material with an increasing Ni-doping (5% of Ni increases R by more than 1000 times). The resistivity peaks at various magnetic fields collapses on themselves at the high temperature ends above the MIT. We also performed magnetization versus temperature measurements on both Ni-free the Ni-doped samples for FC and ZFC states. The FC and ZFC curves rapidly decrease to paramagnetic state at 175 K and 130 K for ZFC and FC states, respectively. For other Ni-doped samples, we observed a reduction in the paramagnetic transition temperature with increasing Ni concentration.