Papers by Farchi abdelmajid
Indonesian Journal of Electrical Engineering and Computer Science
Many power converter architectures and control approaches, both traditional and unconventional, h... more Many power converter architectures and control approaches, both traditional and unconventional, have been developed, investigated, and adjusted to handle the challenge of tracking the maximum power points of a partially shaded photovoltaic (PV) system, which fluctuates with meteorological conditions (radiation and temperature). A DC-DC converter was used as the power conditioning unit to determine the system’s maximum efficiency. In this research, we focus on developing a nonlinear controller for a DC-DC converter to track the overall maximum power point in a PV storage system under partial shading situations. This study presents a combination of two MPP search algorithms with a backstepping controller. The particle swarm optimization (PSO) and variable step Perturb and Observe (P&O)with global scan (VSP&O/GS) algorithms supply the PV output reference voltage to the backstepping controller in order to recover the maximum power from photovoltaic (PV) systems. The simulation results o...
Bookmarks Related papers MentionsView impact
2021 9th International Renewable and Sustainable Energy Conference (IRSEC)
We are interested in tracking the maximum power of a partially shaded photovoltaic (PV) system, u... more We are interested in tracking the maximum power of a partially shaded photovoltaic (PV) system, using a DC-DC converter as the power conditioning unit. To meet this objective, many structures of power converters and different conventional and non-conventional control methods have been proposed, studied, and optimized. Among them the conventional method of perturbation and observation (P&O), and the unconventional method of particle swarm optimization (PSO), which remain the most known MPPT techniques due to their simplicity. But their dynamic response and accuracy remain low compared to other optimized methods. This work presents a comparative analysis between five control strategies: i) the conventional (P&O) method with fixed iteration step, ii) variable step (VSP&O), iii) modified adjustable step (imVSP&O). iv) The improved perturbation and global scanning and observation method (VSPO&GS). V) The unconventional method based on artificial intelligence PSO. The simulation results of these algorithms are analyzed and compared in the Matlab/Simulink environment in order to show the performances and the limits of each method in the tracking of the point of maximum power.
Bookmarks Related papers MentionsView impact
International Journal of Electrical and Computer Engineering (IJECE), 2021
The speech signal is described as many acoustic properties that may contribute differently to spo... more The speech signal is described as many acoustic properties that may contribute differently to spoken word recognition. Vowel characterization is an important process of studying the acoustic characteristics or behaviors of speech within different contexts. This current study focuses on the modulators characteristics of three Arabic vowels, we proposed a new approach to characterize the three Arabic vowels /a/, /i/ and /u/. The proposed method is based on the energy contained in the speech modulators. The coherent subband demodulation method related to the spectral center of gravity (COG) was used to calculate the energy of the speech modulators. The obtained results showed that the modulators energy help characterize the Arabic vowels /a/, /i/ and /u/ with an interesting recognition rate ranging from 86% to 100%.
Bookmarks Related papers MentionsView impact
The present study investigates acoustic effect of consonants /b/, / d/, / k/ in Modern Standard A... more The present study investigates acoustic effect of consonants /b/, / d/, / k/ in Modern Standard Arabic (MSA). To study coarticulatory effects when introducing vowel /a/, /i/ and, /u/, ten Moroccan speakers were recorded to pronounce the consonants /b/, /d/, /k/ in different contexts CV, and VCV. In VCV context, the introduction of first vowel leads to a variation in F2 onset of the consonant and an increase in the carry-over effect
Bookmarks Related papers MentionsView impact
International Journal of Engineering Trends and Technology, 2021
With the Coronavirus becoming a huge threat, the world is experiencing a very uncertain situation... more With the Coronavirus becoming a huge threat, the world is experiencing a very uncertain situation. In Morocco, especially after confinement, the number of cases has increased dramatically;this sudden increase is due to several factors, including public transport. This is where our project derives its interest, because thanks to the many alternatives it offers, it reduces the risk of contamination, which makes it possible to reduce the cases of illnesses linked to Covid-19 as well as to reduce the rate of accidents. To achieve our goal, the transport will be equipped with new technologies boosted by artificial intelligence and other tools, a passenger so that he can board the bus must be wearing a facial mask detected through an artificial intelligence-based mask detector. Covid-19 not only affects the physical health of the person, but it has a major impact on mental health, especially for drivers who are more involved to be infected by the virus. For this, there is an emotion recognition system based on AI and social intelligence that detects the emotions of the driver and generates actions that correct, regulate and stabilize their emotional state. A deep learning algorithm has been applied, and an accuracy rate of 91.23% was found in CNN with only 300 epochs. © 2021 Seventh Sense Research Group.
Bookmarks Related papers MentionsView impact
International Journal of Electrical and Computer Engineering (IJECE), 2022
Many technology systems have used voice recognition applications to transcribe a speaker’s speech... more Many technology systems have used voice recognition applications to transcribe a speaker’s speech into text that can be used by these systems. One of the most complex tasks in speech identification is to know, which acoustic cues will be used to classify sounds. This study presents an approach for characterizing Arabic fricative consonants in two groups (sibilant and non-sibilant). From an acoustic point of view, our approach is based on the analysis of the energy distribution, in frequency bands, in a syllable of the consonant-vowel type. From a practical point of view, our technique has been implemented, in the MATLAB software, and tested on a corpus built in our laboratory. The results obtained show that the percentage energy distribution in a speech signal is a very powerful parameter in the classification of Arabic fricatives. We obtained an accuracy of 92% for non-sibilant consonants /f, χ, ɣ, ʕ, ћ, and h/, 84% for sibilants /s, sҁ, z, Ӡ and ∫/, and 89% for the whole classific...
Bookmarks Related papers MentionsView impact
International Journal of Electrical and Computer Engineering (IJECE), 2019
We are considering the problem of maximum power point tracking MPPT in wind energy conversion sys... more We are considering the problem of maximum power point tracking MPPT in wind energy conversion system (WECS). The paper proposes a new control strategy to maximize the wind aerodynamic energy captured in variable speed wind turbine with a separately excited DC-Generator and transformed to the battery through a controlled DC-DC converter. The proposed strategy controls the stip speed ratio via the rotor angular speed to an optimum point at wich the power coefficient is maximal. The controller is designed using the backstepping technique. A formal analysis based on lyapunov stability is developed to describe the control system performances. In addition to closed-loop global asymptotic stability, it is proved that the controller actually meets the MPPT requirement. The above results are confirmed by simulations.
Bookmarks Related papers MentionsView impact
International Journal of Electrical and Computer Engineering (IJECE)
We usually encounter two problems during speech emotion recognition (SER): expression and percept... more We usually encounter two problems during speech emotion recognition (SER): expression and perception problems, which vary considerably between speakers, languages, and sentence pronunciation. In fact, finding an optimal system that characterizes the emotions overcoming all these differences is a promising prospect. In this perspective, we considered two emotional databases: Moroccan Arabic dialect emotional database (MADED), and Ryerson audio-visual database on emotional speech and song (RAVDESS) which present notable differences in terms of type (natural/acted), and language (Arabic/English). We proposed a detection process based on 27 acoustic features extracted from consonant-vowel (CV) syllabic units: \ba, \du, \ki, \ta common to both databases. We tested two classification strategies: multiclass (all emotions combined: joy, sadness, neutral, anger) and binary (neutral vs. others, positive emotions (joy) vs. negative emotions (sadness, anger), sadness vs. anger). These strategie...
Bookmarks Related papers MentionsView impact
International Journal of Electrical and Computer Engineering (IJECE), 2021
The speech signal is described as many acoustic properties that may contribute differently to spo... more The speech signal is described as many acoustic properties that may contribute differently to spoken word recognition. Vowel characterization is an important process of studying the acoustic characteristics or behaviors of speech within different contexts. This current study focuses on the modulators characteristics of three Arabic vowels, we proposed a new approach to characterize the three Arabic vowels /a/, /i/ and /u/. The proposed method is based on the energy contained in the speech modulators. The coherent subband demodulation method related to the spectral center of gravity (COG) was used to calculate the energy of the speech modulators. The obtained results showed that the modulators energy help characterize the Arabic vowels /a/, /i/ and /u/ with an interesting recognition rate ranging from 86% to 100%.
Bookmarks Related papers MentionsView impact
Uploads
Papers by Farchi abdelmajid