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In this paper, a microwave imaging technique for reconstructing the shape of two-dimensional perfectly conducting scatterers by means of a stochastic optimization approach is investigated. Based on the boundary condition and the measured scattered field derived by transverse magnetic illuminations, a set of nonlinear integral equations is obtained and the imaging problem is reformulated in to an optimization...
The Tunisian SAHEL railway supply system of 68 km length track is fed by one electrical substation 150kV/25kV. The overhead line is modeled as distributed circuit, as a result the frequency and locomotive position dependant impedances of the line are studied using Telegrapher's model. The current harmonic amplification as a function of frequency and train location seen from substation in the case...
The foot and ankle contribute significantly to postural control by providing a contact area to the support surface. Persons with visual and neuromuscular disorders have deficits in response to perturbations of balance and often require assistive devices. This work investigated to posture analysis by using plantar pressure measurements coupled with an EMG analog signal processor. The output signals...
This paper deals with the use of coupled inductors for the DC|DC converters. A complete analysis of this topology is carried out and its advantages are demonstrated by comparing it to the DC/DC converter with uncoupled inductor. In this paper, we show how the coupled inductors allow the I2R losses reduction and the minimization of the phase and the output current ripples. Different architectures and...
The ocular fundus image can provide information on pathological changes caused by local ocular diseases and early signs of certain systemic diseases, such as diabetes and hypertension. Automated analysis and interpretation of fundus images has become a necessary and important diagnostic procedure in ophthalmology. The extraction of blood vessels from retinal images is an important and challenging...
The progress of electronics and data processing contributed to the development of the measurement techniques of the virtual instruments. To contribute to this work one carried out an instrumental platform managed by Labview. The conceived measurement system is a multifunction. It ensures the measurement of the active, reactive and apparent power as well as the power-factor and the characterization...
Due to the large increase in number of installed high power renewable energy generating systems such as wind energy power plants, one of the important evolving requirement is riding through the fault at low or zero voltage. In this paper, the unified power flow controller is deployed in power systems with high penetration of renewable energy units to achieve low voltage ride through capability. Matlab/Simulink...
A comparative study of methods for fractional system identification is presented in this paper. The fractional system is modeled by the help of a non integer integrator which is approximated by a J+1 dimensional modal system composed of an integrator and first order systems. This identification method is compared to other techniques available in the Matlab toolbox. The model parameters are estimated...
In this paper wavelet decomposition is combined with autoregressive models to analyze and predict climate time series such as solar radiation and photovoltaic cell temperature. The method is tested on climate parameters for analysis, and solar radiation and cell temperature for prediction. The work effectiveness is evaluated by the prediction of the electric energy produced by a 100 Wp photovoltaic...
The energy band diagram and space charge regions of Schottky barrier (SB) solar cells are different from normal pn solar cells. Many facts and theories must be studied and developed to assist understanding and implementing SB solarcells. Few samples of SB devices were prepared by thermal deposition under vacuum then tested and studied carefully. An interfacial layer was introduced between metal and...
In this paper, conditions on the the fault detection and the fault accommodation delays are defined and developed in order to guarantee the actuator fault's recoverability. The study is based on the classical Pseud-Inverse Method PIM, used as an active fault tolerant control. A performance index dealing with the variation between the nominal dynamic and the faulty one is defined and computed for different...
This paper presents the decentralized fault-tolerant tracker based on the model predictive control (MPC) for a class of unknown interconnected large-scale sampled-data nonlinear systems. Due to the computational requirements of MPC and the system information is unknown, the observer/Kalman filter identification (OKID) method is utilized to determine decentralized appropriate (low-) order discrete-time...
Neural techniques for modeling and control of the diving motion of an underwater vehicle are presented in this article. The system under consideration is a remotely operated vehicle the Phantom 500. The direct training method is used to elaborate the direct and inverse neural models with the consideration of system non linearity and unmeasured disturbances presence. Three different inverse model based...
Every photovoltaic (PV) array has unique point at which maximum power can be generated and extracted for different atmospheric conditions and output load. The maximum power point tracking is therefore critical for the success of PV arrays. All methods proposed earlier suffer from slow response; they oscillate around the maximum power point and ignoring the atmospheric conditions changing. This paper...
This paper deals with observability problems of the parallel multi-cell chopper. This type of choppers is a new DC/DC static power converter which has an output current equals to n times the source current where n is the number of cells. After recalling the dynamical equations of the converter, its hybrid dynamical behavior and properties are highlighted. This particular hybrid system induces new...
In this paper, we present a performance study of a variable pitch wind turbine with a Permanent Magnet Synchronous Generator (PMSG). The control strategy used Maximum Power Point Tracking (MPPT) below the rated speed, which corresponds to low and high wind speed, and the maximum energy can be captured from the wind. The Pitch angle control which is the most common means for adjusting the aerodynamic...
In this paper we are going to present a monitoring approach of dynamic systems by using the hybrid automaton. At first we shall use the linear hybrid automatons, in continuation we are going to enrich our monitoring method by using the rectangular hybrid automatons. This work is based on the observation of the dynamic evolution of these systems, and activates an alarm if there is any infringement...
In this paper, a modified fuzzy c-regression model (FCRM) clustering algorithm for identification of Takagi-Sugeno (T-S) fuzzy model is proposed. The FCRM clustering algorithm has considerable sensitive to noise. To overcome this problem, a modified FCRM clustering algorithm is presented. This latter is based to adding a second regularization term in the alternative optimization process of FCRM. This...
In this paper, we present a combination of the Terminal sliding mode control (TSMC) and Fuzzy Logic (FL) technique. This approach called Fuzzy Terminal Sliding Mode Control (FTSMC) can compensate the chattering problem caused by (TSMC). In addition, this technique can decrease significantly the rule number and present the robustness compared with the parameters uncertainty and external disturbance...
This paper introduces the particle-filtering (PF) based framework for fault diagnosis in non-linear systems and noise and disturbances being Gaussian. In this paper, we use the sequential Monte Carlo filtering approach where the complete posterior distribution of the estimates are represented through samples or particles as opposed to the mean and covariance of an approximated Gaussian distribution...
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