This study aims to assess the diversity and distribution of fungal mycoflora developing on Cedrus atlantica (Endl) G. Manetti ex Carrière needles in three sites in the Belezma National Park (Biosphere Reserve, Northeast - Algeria). Three sites were sampled according to a cedar decline gradient, these are the massifs of: Telmet (healthy site), Boumerzoug (moderately depressed) and Tougurt (decayed site). Polymerase chain reaction (PCR) molecular analysis, allows identifying 19 endophytic mycotaxa. All the identified species have a weak occurrence frequency (less than 25%). In terms of specific richness, the moderately depressed site (Boumerzoug) homes the largest number of taxa (S = 17), followed by healthy site of Telmet (12 taxa), while the depressed site of Tougurt was the least populated (8 taxa). The hierarchical classification analysis (HCA) showed that the taxonomic composition of endophyte associations differs clearly from one site to another according to the cedar decline. The clustering representing healthy massif brings 2 species which are demanding phytoparasitic endophytes (Fusarium sp. and Xylaria sp.). The group associated to moderately depressed site hosts 7 taxa with a wide ecological valence, such as: Canariomyces notabilis, Canariomyces vonarxii, Chaetomium aegilopis, Coniolariella hispanica and Penicillium kubanicum. Then, mycoflora group noted in the decayed cedar includes 10 taxa, in particular, saprophytic mycotaxa relatively less demanding with a high ecological valence like: Biscogniauxia mediterranea, Alternaria arborescens, A. tenuissima and three species of Chaetomium genus. The mycotaxa distribution is related to the specific conditions of colonized trees. Taxa specific to healthy and decayed massifs would represent bio indicators of the phytosanitary and ecological conditions of colonized cedars.

This study aims to assess the diversity and distribution of fungal mycoflora developing on Cedrus atlantica (Endl) G. Manetti ex Carrière needles in three sites in the Belezma National Park (Biosphere Reserve, Northeast - Algeria). Three sites were sampled according to a cedar decline gradient, these are the massifs of: Telmet (healthy site), Boumerzoug (moderately depressed) and Tougurt (decayed site). Polymerase chain reaction (PCR) molecular analysis, allows identifying 19 endophytic mycotaxa. All the identified species have a weak occurrence frequency (less than 25%). In terms of specific richness, the moderately depressed site (Boumerzoug) homes the largest number of taxa (S = 17), followed by healthy site of Telmet (12 taxa), while the depressed site of Tougurt was the least populated (8 taxa). The hierarchical classification analysis (HCA) showed that the taxonomic composition of endophyte associations differs clearly from one site to another according to the cedar decline. The clustering representing healthy massif brings 2 species which are demanding phytoparasitic endophytes (Fusarium sp. and Xylaria sp.). The group associated to moderately depressed site hosts 7 taxa with a wide ecological valence, such as: Canariomyces notabilis, Canariomyces vonarxii, Chaetomium aegilopis, Coniolariella hispanica and Penicillium kubanicum. Then, mycoflora group noted in the decayed cedar includes 10 taxa, in particular, saprophytic mycotaxa relatively less demanding with a high ecological valence like: Biscogniauxia mediterranea, Alternaria arborescens, A. tenuissima and three species of Chaetomium genus. The mycotaxa distribution is related to the specific conditions of colonized trees. Taxa specific to healthy and decayed massifs would represent bio indicators of the phytosanitary and ecological conditions of colonized cedars.

In this paper, first we show that the analytical solutions obtained in  the literature for the new coupled Konno-Oono system can be immediately presented  via the Weierstrass elliptic function or Jacobi elliptic functions. Next, we present a  new general real dark-type of soliton and a complex bright-type of envelope soliton  to this system in terms of the solutions of the sine-Gordon and sinh-Gordon equations  involving an arbitrary function via two new different transformations.

In this paper, first we show that the analytical solutions obtained in  the literature for the new coupled Konno-Oono system can be immediately presented  via the Weierstrass elliptic function or Jacobi elliptic functions. Next, we present a  new general real dark-type of soliton and a complex bright-type of envelope soliton  to this system in terms of the solutions of the sine-Gordon and sinh-Gordon equations  involving an arbitrary function via two new different transformations.

In this paper, first we show that the analytical solutions obtained in  the literature for the new coupled Konno-Oono system can be immediately presented  via the Weierstrass elliptic function or Jacobi elliptic functions. Next, we present a  new general real dark-type of soliton and a complex bright-type of envelope soliton  to this system in terms of the solutions of the sine-Gordon and sinh-Gordon equations  involving an arbitrary function via two new different transformations.

The main idea of this study is to evaluate the estimation performance of extended and unscented Kalman filters (EKF and UKF). So, these latter are introduced to estimate the dynamic states of a similar model operating with identical covariance matrices in the same situation. The mean square error (MSE) criterion is used to quantify the estimation error between the actual and the estimated values. The simulation results obtained with Matlab/ Simulink software confirm the superiority and efficiency of UKF over EKF, especially when the system is highly non-linear under process and measurement noises, such is the case of the inverted double pendulum mounted on a cart (DIPC).

The main idea of this study is to evaluate the estimation performance of extended and unscented Kalman filters (EKF and UKF). So, these latter are introduced to estimate the dynamic states of a similar model operating with identical covariance matrices in the same situation. The mean square error (MSE) criterion is used to quantify the estimation error between the actual and the estimated values. The simulation results obtained with Matlab/ Simulink software confirm the superiority and efficiency of UKF over EKF, especially when the system is highly non-linear under process and measurement noises, such is the case of the inverted double pendulum mounted on a cart (DIPC).

The main idea of this study is to evaluate the estimation performance of extended and unscented Kalman filters (EKF and UKF). So, these latter are introduced to estimate the dynamic states of a similar model operating with identical covariance matrices in the same situation. The mean square error (MSE) criterion is used to quantify the estimation error between the actual and the estimated values. The simulation results obtained with Matlab/ Simulink software confirm the superiority and efficiency of UKF over EKF, especially when the system is highly non-linear under process and measurement noises, such is the case of the inverted double pendulum mounted on a cart (DIPC).

The main idea of this study is to evaluate the estimation performance of extended and unscented Kalman filters (EKF and UKF). So, these latter are introduced to estimate the dynamic states of a similar model operating with identical covariance matrices in the same situation. The mean square error (MSE) criterion is used to quantify the estimation error between the actual and the estimated values. The simulation results obtained with Matlab/ Simulink software confirm the superiority and efficiency of UKF over EKF, especially when the system is highly non-linear under process and measurement noises, such is the case of the inverted double pendulum mounted on a cart (DIPC).

This paper proposes a new approach of multi-spectral image compression based on the combination of the particle swarm optimization (PSO) and the discrete wavelet transforms (DWT). In the first stage, the PSO is used to reduce the redundancies in the spectral domain. In fact, the PSO transforms a given multispectral image to optimize the energy in the first band. Despite to the complexity of this kind of approach, the transformed multispectral image is easily computed by multiplying a de-correlation matrix and the input multispectral image. The de-correlation matrix is estimated via a PSO evolution derived by a defined fitness function. In the second stage, the compressed data, related to the input multispectral image, is computed from the transformed multispectral image using an efficient 2D-DWT based algorithm. In addition to this compression approach, the original multispectral image can be recovered using a decompression algorithm. Experimental results show the validity of our proposed approach. These significant results are evaluated according to Peak signal-to-noise ratio (PSNR), compression ratio (CR) and bits per pixel (bpp) metrics.

This paper proposes a new approach of multi-spectral image compression based on the combination of the particle swarm optimization (PSO) and the discrete wavelet transforms (DWT). In the first stage, the PSO is used to reduce the redundancies in the spectral domain. In fact, the PSO transforms a given multispectral image to optimize the energy in the first band. Despite to the complexity of this kind of approach, the transformed multispectral image is easily computed by multiplying a de-correlation matrix and the input multispectral image. The de-correlation matrix is estimated via a PSO evolution derived by a defined fitness function. In the second stage, the compressed data, related to the input multispectral image, is computed from the transformed multispectral image using an efficient 2D-DWT based algorithm. In addition to this compression approach, the original multispectral image can be recovered using a decompression algorithm. Experimental results show the validity of our proposed approach. These significant results are evaluated according to Peak signal-to-noise ratio (PSNR), compression ratio (CR) and bits per pixel (bpp) metrics.

The mast support for small vertical axis wind turbine is considered an important parameter during the design process of wind turbine structure. It has been receiving a great attention by researchers and academics. This study presents a numerical investigation on the static and buckling strength behaviors of whole wind turbine mast structure by means Finite Element Analysis (FEA) technique. The FEA simulations are performed in order to evaluate the reliability and the strength of the mast structure under the extreme wind conditions (IEC 61400-2 and Eurocode 1991-1-4 standards) and gravity loads. The simulation results show that the mast structure will not undergo structural failure because the maximum stress induced is less than the yield strength of the material and the maximum displacement is within material allowable deformation limit. In addition, the buckling strength of the structure meets requirement of design.

The mast support for small vertical axis wind turbine is considered an important parameter during the design process of wind turbine structure. It has been receiving a great attention by researchers and academics. This study presents a numerical investigation on the static and buckling strength behaviors of whole wind turbine mast structure by means Finite Element Analysis (FEA) technique. The FEA simulations are performed in order to evaluate the reliability and the strength of the mast structure under the extreme wind conditions (IEC 61400-2 and Eurocode 1991-1-4 standards) and gravity loads. The simulation results show that the mast structure will not undergo structural failure because the maximum stress induced is less than the yield strength of the material and the maximum displacement is within material allowable deformation limit. In addition, the buckling strength of the structure meets requirement of design.

The mast support for small vertical axis wind turbine is considered an important parameter during the design process of wind turbine structure. It has been receiving a great attention by researchers and academics. This study presents a numerical investigation on the static and buckling strength behaviors of whole wind turbine mast structure by means Finite Element Analysis (FEA) technique. The FEA simulations are performed in order to evaluate the reliability and the strength of the mast structure under the extreme wind conditions (IEC 61400-2 and Eurocode 1991-1-4 standards) and gravity loads. The simulation results show that the mast structure will not undergo structural failure because the maximum stress induced is less than the yield strength of the material and the maximum displacement is within material allowable deformation limit. In addition, the buckling strength of the structure meets requirement of design.

As a key wind turbine element, the blade is a determining factor for reliability and efficiency of the turbine system and a main source of complicated and critical loads. In this present investigation, the strength behavior of a small composite blade for H-type Darrieus wind turbine was studied. Firstly, three-dimensional (3D) modelling of the blade structure with NACA 0018 airfoil profile was established. Secondly, the Finite element analysis (FEA) technique was conducted to perform the strength analysis of the blade structure subjected to extreme climatic conditions by means SOLIDWORKS SIMULATION software. This analysis was performed to identify the resistance, stiffness and reliability of the composite blade structure. The results from FEA identify that the structure of the blade will not be subjected to structural failure during WT operation (0 ~ 19 m/s) according to maximum principal stress equivalent (von Mises) and maximum displacements.

As a key wind turbine element, the blade is a determining factor for reliability and efficiency of the turbine system and a main source of complicated and critical loads. In this present investigation, the strength behavior of a small composite blade for H-type Darrieus wind turbine was studied. Firstly, three-dimensional (3D) modelling of the blade structure with NACA 0018 airfoil profile was established. Secondly, the Finite element analysis (FEA) technique was conducted to perform the strength analysis of the blade structure subjected to extreme climatic conditions by means SOLIDWORKS SIMULATION software. This analysis was performed to identify the resistance, stiffness and reliability of the composite blade structure. The results from FEA identify that the structure of the blade will not be subjected to structural failure during WT operation (0 ~ 19 m/s) according to maximum principal stress equivalent (von Mises) and maximum displacements.

As a key wind turbine element, the blade is a determining factor for reliability and efficiency of the turbine system and a main source of complicated and critical loads. In this present investigation, the strength behavior of a small composite blade for H-type Darrieus wind turbine was studied. Firstly, three-dimensional (3D) modelling of the blade structure with NACA 0018 airfoil profile was established. Secondly, the Finite element analysis (FEA) technique was conducted to perform the strength analysis of the blade structure subjected to extreme climatic conditions by means SOLIDWORKS SIMULATION software. This analysis was performed to identify the resistance, stiffness and reliability of the composite blade structure. The results from FEA identify that the structure of the blade will not be subjected to structural failure during WT operation (0 ~ 19 m/s) according to maximum principal stress equivalent (von Mises) and maximum displacements.

As a key wind turbine element, the blade is a determining factor for reliability and efficiency of the turbine system and a main source of complicated and critical loads. In this present investigation, the strength behavior of a small composite blade for H-type Darrieus wind turbine was studied. Firstly, three-dimensional (3D) modelling of the blade structure with NACA 0018 airfoil profile was established. Secondly, the Finite element analysis (FEA) technique was conducted to perform the strength analysis of the blade structure subjected to extreme climatic conditions by means SOLIDWORKS SIMULATION software. This analysis was performed to identify the resistance, stiffness and reliability of the composite blade structure. The results from FEA identify that the structure of the blade will not be subjected to structural failure during WT operation (0 ~ 19 m/s) according to maximum principal stress equivalent (von Mises) and maximum displacements.

As a key wind turbine element, the blade is a determining factor for reliability and efficiency of the turbine system and a main source of complicated and critical loads. In this present investigation, the strength behavior of a small composite blade for H-type Darrieus wind turbine was studied. Firstly, three-dimensional (3D) modelling of the blade structure with NACA 0018 airfoil profile was established. Secondly, the Finite element analysis (FEA) technique was conducted to perform the strength analysis of the blade structure subjected to extreme climatic conditions by means SOLIDWORKS SIMULATION software. This analysis was performed to identify the resistance, stiffness and reliability of the composite blade structure. The results from FEA identify that the structure of the blade will not be subjected to structural failure during WT operation (0 ~ 19 m/s) according to maximum principal stress equivalent (von Mises) and maximum displacements.

L'article décrit la conception et la mise en œuvre en temps réel d'une commande non linéaire appliquée à un système de conversion de l'énergie éolienne (SCEE). La commande backstepping a été mise en œuvre pour améliorer les performances du système de conversion éolienne basé sur un générateur synchrone à aimants permanents (PMSG) connecté au réseau. Deux convertisseurs statiques assurent la connexion au réseau et sont contrôlés par la modulation de largeur d'impulsion (MLI). L'algorithme de contrôle proposé assure un contrôle de vitesse adéquat pour extraire la puissance maximale. Une description détaillée des lois de contrôle du backstepping basées sur la technique de stabilité de Lyapunov a été exposée. Les résultats obtenus par l'application de cette approche ont clairement répondu aux exigences de robustesse et de suivi des références même dans des conditions de vent fluctuants, et ont confirmé l'efficacité d'un tel contrôle dans les modes de fonctionnement statique et dynamique.