Adama Konaté - Academia.edu (original) (raw)

Papers by Adama Konaté

HAL (Le Centre pour la Communication Scientifique Directe), Oct 1, 2017

We investigate the effect of the cubic nonlinear gain on the resonance curve in the frame of the ... more We investigate the effect of the cubic nonlinear gain on the resonance curve in the frame of the dissipative soliton resonance (DSR) in a complex cubic-quintic Ginzburg-Landaumodel. The DSR occurs when the energy of a soliton in the system increases without limit at certain values of the system parameters. We remind analytical expression for the resonance curve, thanks to the collective variable approach. We show that the nonlinear gain has a linear response for the spectral filtering and the saturation of the Kerr nonlinearity, however, has a nonlinear response for the linear loss and the saturation of the nonlinear gain. Thus the gain and its saturation in the system can be suitably chosen for generation of high-energy pulses. These results can be helpful to design laser systems or to optimize the active parameters of cavities that generate solitons with the highest possible energy.

Engineering, 2021

This paper addresses the problem of the opportunistic spectrum access in Cognitive Radio. Indeed,... more This paper addresses the problem of the opportunistic spectrum access in Cognitive Radio. Indeed, most spectrum sensing algorithms suffer from a high computational cost to achieve the detection process. They need a prior knowledge of signal characteristics and present a bad performance in low Signal to Noise Ratio (SNR) environment. The choice of the optimal detection threshold is another issue for these spectrum sensing algorithms. To overcome the limits of spectrum detectors, we propose in this paper, a blind detection method based on the cyclostationary features of communication signals. Our detector evaluates the level of hidden periodicity contained in the observed signal to make decision on the state of a bandwidth. In order to reduce the computational cost, we take advantage of the FFT Accumulation Method to estimate the cyclic spectrum of the observed signal. Then, we generate the Cyclic Domain Profile of the cyclic spectrum which allows us to evaluate the level of the hidden periodicity in the signal. This level of periodicity is quantified through the crest factor of Cyclic Domain Profile, which represents the decision statistic of the proposed detector. We have established the analytic expression of the optimal threshold of the detection and the probability of detection to evaluate the performance of the proposed detector. Simulation results show that the proposed detector is able to detect the presence of a communication signal on a bandwidth in a very low SNR scenario.

IET Microwaves, Antennas & Propagation, 2021

The characteristics of multipath components (MPCs) are addressed in an industrial environment at ... more The characteristics of multipath components (MPCs) are addressed in an industrial environment at 1.3 GHz by means of measurements with a multidimensional channel sounder. The maximum likelihood estimator, RiMAX, is used to determine the MPCs parameters and takes into account the diffuse scattering. Both line-of-sight (LOS) and obstructed LOS (OLOS) scenarios have been considered, along with the four polarization states. We found that the environment is very rich in multipath, that is on average, about 120 (resp. 70) MPCs in LOS (resp. OLOS) scenario due to the presence of several metallic reflectors. The azimuthal angle implies clustering of the MPCs, and therefore, the estimated MPCs are grouped in clusters using the K-powers-means algorithm based on the multipath component distance. In general, one to four clusters are determined with three clusters occurring with the highest probability, regardless of the scenario. Next, the intra-cluster parameters have been determined, and we show that the root-mean-square (rms) delay spread and rms angular spread follow a gamma distribution, regardless of the polarization. The MPC characteristics agree with the results in the literature and can be valuable when deploying a wireless sensor network in industrial environments. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

International Journal of Materials Engineering and Technology, 2021

This article calculates the elements of a filter (L-C) for an inverter with 180 control in HTA. ... more This article calculates the elements of a filter (L-C) for an inverter with 180 control in HTA. First a verification of the formulas of the capacitance of the capacitor C and the inductance L of the filter (L-C) of an inverter SPWM for the inverter with 180 control in MV has been made. It appears that these formulas obtained by minimizing the reactive power of the filter (capped at 5% of the apparent power of the load) and the ripple of the current flowing through inductance L (the voltage drop at the terminals of the alternating load is capped at 10%) cannot give THDs that comply with the IEEE 519-2014 standard. Then we determined formulas from the equations written on the filter (L-C) and the 180 control inverter. The application of these formulas gives satisfactory results. The simulation was performed on the MATLAB-Simulink software.

A reduced-order discrete-time Extended Sliding Mode Observer (ESMO) is introduced, in this paper,... more A reduced-order discrete-time Extended Sliding Mode Observer (ESMO) is introduced, in this paper, for on-line estimation of rotor fluxes and rotor time constant. The satisfying simulations results on Matlab-Simulink © environment and experimental results carried out on a 1,8 kW induction machine demonstrate the excellent performance and high robustness of the proposed ESMO against parameter variations, modeling uncertainty and measurement noise. It is concluded that the implementation in real-time of this reduced-order ESMO in the industrial applications, compared with the full-order ESMO, permit on the one hand to overcome the heavy computational effort, complexity and hard tuning of the estimation algorithm and, on the other hand, to reduce the execution time of the observation with a good accuracy and considerable rapidity.

This article presents an industrializable silicon-based microhotplate for metal oxide gas sensors... more This article presents an industrializable silicon-based microhotplate for metal oxide gas sensors. It introduces an interesting approach and describes the technological optimizations used to reach high and stable operating temperature, in reducing intrinsic drift problems (due to commercial polysilicon heater). The microhotplate present low consumption of 70 mW for 600°C, good thermal homogeneity over the active area and a good mechanical stability.

Far East Journal of Electronics and Communications, 2020

We have proposed a transformer type SFCL whose primary and secondary superconducting coils have r... more We have proposed a transformer type SFCL whose primary and secondary superconducting coils have rewound structure. The primary coil is connected to a power line. The secondary one is short-circuited and has less turns than the primary coil. For small fault current, only the secondary coil turns to normal state. Inductive component of impedance at the primary terminal mainly appears. For larger fault current, the primary coil also turns to normal state, resistive component additively appears. A three-phase concentric model of the proposed SFCL was designed and fabricated. Each phase SFCL must works independently without large interference among phases. Fundamental current limiting characteristics of the proposed SFCL were reported at a three-line-to-ground fault using a lab scale power transmission system. In this paper, current limiting performance of the SFCL at unbalanced fault conditions was investigated and discussed. Influence of operations of the fault phase SFCL to the non-fault phase ones was discussed. It was confirmed that fault current limiting operation was successfully performed in single-line-to-ground fault, double-line-short fault and double-line-ground fault.

Humanities & Social Sciences Reviews, 2019

Purpose: To study the development of teenage club activity in the Orenburg region from 1931 till ... more Purpose: To study the development of teenage club activity in the Orenburg region from 1931 till 1958 in the Soviet out-of-school work in a national context. Methodology: The main stages are defined and their descriptive characteristic is given on the basis of proposed and formulated criteria via comparative qualitative research methods. Main Findings: The leaders of the club associations where children from families with difficulties and problems can be met and given qualified consultation. The development of the teenage club activity in the Orenburg region is represented by three periods of development, decline and flourishing. Applications: This research can be used at universities, historical organizations, and culture-literature institutes and by graduate students in history. Novelty/Originality: The paper explored the history of the regional system of teenage club activities in the Orenburg region which is becoming of particular importance as it allows to think critically and ...

Far East Journal of Mathematical Sciences (FJMS), 2019

Asian Journal of Applied Sciences, 2016

Journal of Applied Mathematics and Physics, 2015

We feature the stationary solutions of the 3D complex cubic-quintic Ginzburg-Landau equation (CGL... more We feature the stationary solutions of the 3D complex cubic-quintic Ginzburg-Landau equation (CGLE). Our approach is based on collective variables approach which helps to obtain a system of variational equations, giving the evolution of the light pulses parameters as a function of the propagation distance. The collective variables approach permits us to obtain, efficiently, a global mapping of the 3D stationary dissipative solitons. In addition it allows describing the influence of the parameters of the equation on the various physical parameters of the pulse and their dynamics. Thus it helps to show the impact of dispersion and nonlinear gain on the stationary dynamic.

Intelligent Control and Automation, 2016

This paper presents a robust sixth-order Discrete-time Extended Sliding Mode Observer (DESMO) for... more This paper presents a robust sixth-order Discrete-time Extended Sliding Mode Observer (DESMO) for sensorless control of PMSM in order to estimate the currents, speed, rotor position, load torque and stator resistance. The satisfying simulation results on Simulink/Matlab environment for a 1.6 kW PMSM demonstrate the good performance and stability of the proposed ESMO algorithm against parameter variation, modeling uncertainty, measurement and system noises.

Engineering, 2015

This paper uses a robust feedback linearization strategy in order to assure a good dynamic perfor... more This paper uses a robust feedback linearization strategy in order to assure a good dynamic performance, stability and a decoupling of the currents for Permanent Magnet Synchronous Motor (PMSM) in a rotating reference frame (d, q). However this control requires the knowledge of certain variables (speed, torque, position) that are difficult to access or its sensors require the additional mounting space, reduce the reliability in harsh environments and increase the cost of motor. And also a stator resistance variation can induce a performance degradation of the system. Thus a sixth-order Discrete-time Extended Kalman Filter approach is proposed for on-line estimation of speed, rotor position, load torque and stator resistance in a PMSM. The interesting simulations results obtained on a PMSM subjected to the load disturbance show very well the effectiveness and good performance of the proposed nonlinear feedback control and Extended Kalman Filter algorithm for the estimation in the presence of parameter variation and measurement noise.

The sensor presented in this article consists of a nanostructured tin oxide as high sensitive mat... more The sensor presented in this article consists of a nanostructured tin oxide as high sensitive material and an efficient high temperature microhotplate. Tin oxide nanoparticles are in suspension in a solvent and then are deposited by contactless methods such as microinjections or inkjet printing. The microhotplate has been developed with high electrical and mechanical stabilities up to 650°C with a low power of consumption (<80 mW) and allows an efficient control of temperature, usefull for gases detection. In this work, the gas sensor developed is exposed to different polluting gases like CO, propane and NO2 at different operating temperatures. We determined the optimum working temperature to obtaine the highest sensitivity for each target gas. It is also demonstrated that these gas sensorspresent a best sensitivity compared to commercial Metal oxide gas sensors.

Optics and Photonics Journal, 2017

Dissipative soliton resonance (DSR) is a phenomenon where the energy of a soliton in a dissipativ... more Dissipative soliton resonance (DSR) is a phenomenon where the energy of a soliton in a dissipative system increases without limit at certain values of the system parameters. Using the method of collective variable approach, we have found an approximate relation between the parameters of the normalized complex cubic-quintic Ginzburg-Landau equation where the resonance manifests itself. Comparisons between the results obtained by collective variable approach, and those obtained by the method of moments show good qualitative agreement. This choice also helps to see the influence of the active terms on the resonance curve, so can be very useful in constructing passively mode-locked laser that generate solitons with the highest possible energies.