Université Mouloud Mammeri de Tizi Ouzou
Recent publications
Active Disturbance Rejection Control (ADRC) is a very promising recent concept for the design of controllers to control systems with uncertainties. Based on an extended state observer, this control structure allows both external disturbances and modeling uncertainties to be actively rejected. The use of the active rejection control of disturbances is gaining more and more interest among the system control community. This is mainly due to its easy design, undemanding implementation and robustness. In this paper, three solutions using the ARDC structure to control fractional-order system are discussed. Two methods taken from the literature are briefly introduced, namely, the fractional-order dynamics rejection scheme (FODRS) and the fractional linear active disturbance rejection control (FLADRC). The basic ideas and technical formulations of these two are presented. A third method, based on the robustness performance introduced by fractional-order controllers, is also proposed in this paper. The proposed design method of the set-point tracking controller is based on the Bode’s ideal transfer function (Bode’s ITF). This will improve the robustness of the control scheme.
This paper presents results from numerical investigation into the seismic retrofit of masonry infilled reinforced concrete (RC) frame structures with soft ground story using inverted-Y steel bracing system. The dynamic response of the retrofitted four-story RC frame with an open ground story is evaluated and compared with the response of the original frame. Comparisons are carried out with the variation of the mechanical characteristics of infills in order to investigate the way in which the soft story mechanism occurs. Results from nonlinear dynamic analyses indicate that this type of bracing can effectively eliminate the formation of a soft-story collapse mechanism.
Cork oak (Quercus suber) as a West Mediterranean species is known for its ecological, economic and social values. Wildfires are one of the most serious problems threatening Quercus suber, endangering its occurrence in its area of distribution. Therefore, knowing the behavior of the species after fire and the factors influencing its responses are particularly important for forest management. In this study we assessed the post fire vegetative recovery in 730 trees affected by wildfires on 2014 in Kiadi cork oak forest, located in the Western side of Akfadou Mountains in Algeria. Few months after the fire, individual tree mortality was very low (7.53%), and nearly, all the trees sampled survived the fire since almost all trees resprouted from canopy and some of them showed basal resprouts. Moreover, those two modes of post fire vegetative recovery were not correlated to each other. The performed redundancy analyzes (RDA) revealed that the cork oak post-fire response was highly correlated with individual characteristics and with the environmental data. The main variables influencing the likelihood of good or poor vegetative recovery were the understory height and cover, soil characteristics, fire severity, tree status (alive/dead trees), tree diameter and tree exploitation. Our results confirmed the fire resistance of cork oak species; which is also the only Algerian tree to resprouts. Hence, this makes the species a good candidate for reforestation programs in fire prone ecosystems.
Fuzzy gray-level aura matrices have been developed from fuzzy set theory and the aura concept to characterize texture images. They have proven to be powerful descriptors for color texture classification. However, using them for color texture segmentation is difficult because of their high memory and computation requirements. To overcome this problem, we propose to extend fuzzy gray-level aura matrices to fuzzy color aura matrices, which would allow us to apply them to color texture image segmentation. Unlike the marginal approach that requires one fuzzy gray-level aura matrix for each color channel, a single fuzzy color aura matrix is required to locally characterize the interactions between colors of neighboring pixels. Furthermore, all works about fuzzy gray-level aura matrices consider the same neighborhood function for each site. Another contribution of this paper is to define an adaptive neighborhood function based on information about neighboring sites provided by a pre-segmentation method. For this purpose, we propose a modified simple linear iterative clustering algorithm that incorporates a regional feature in order to partition the image into superpixels. All in all, the proposed color texture image segmentation boils down to a superpixel classification using a simple supervised classifier, each superpixel being characterized by a fuzzy color aura matrix. Experimental results on the Prague texture segmentation benchmark show that our method outperforms the classical state-of-the-art supervised segmentation methods and is similar to recent methods based on deep learning.
Semiconductors as photoelectric catalysis is recognized as a promising strategy for simultaneous face energy crisis and environmental pollution. In this study, amorphous silicon carbide (SiC) thin films were deposited on Si (100) by reactive direct current magnetron sputtering at room temperature of high purity silicon carbide 6H SiC target. By DRX and EPMA analysis, we confirmed the amorphous character of silicon carbide thin layers and the stoichiometric chemical composition respectively. The FTIR measurement confirms the presence of Si–C, Si–Si and Si–O bonds. The peak corresponding to Si–C was found about 777 cm−1. The optical properties were conducted and the optical gap (Eg = 2.236 eV) was determined. The electrochemical properties of amorphous silicon carbide thin films on p-Si substrate were studied and confirmed a p type electrode. By CPG analysis, the conversion of CO2 to methanol was confirmed using silicon carbide as a working electrode. Based on the found results, the SiC@Si based electrode could actually be used as a photocathode for the PEC reduction of CO2 into added value organıc components such as methanol.
A new confined concrete columns design with encased-FRP/Grid components is introduced in this paper. Indeed, partial hexagonal FRP and steel wire grid were discontinuously embedded as strips in the concrete matrix. In this work, a sum of 12 columns specimen were casted and tested under axial compression loading, including concrete-encased-hexagonal FRP strips (FC) and concrete-encased-steel grid strips columns (GC) and unconfined concrete cylinders (P). Experimental results indicate a significant enhancement in the behavior of the composite columns, namely when considering double concrete-encased-strips columns (FGC). In addition, a new confinement model that can be used to predict the axial stress–strain behavior of confined concrete columns is proposed. The confrontation between test and predicted results shows a good agreement. Finally, a parametric analysis was realized to assess the impact of various parameters on the axial behavior of the proposed confinement design technique.
The electrical conductivity of Ca-doped Co 1-xO single crystals was measured as a function of oxygen partial pressure, over the temperature range 1273–1673 K. The results were analyzed using Seebeck coefficient measurements, microstructural characterizations, EELS and X-ray diffraction experiments. From this set of results, we have shown that the influence of calcium on the thermodynamic and transport properties of cobaltous oxide is due to the reducing behavior of these solute cations, leading to both the shift of the Co/CoO phase boundary to higher PO2 and the formation of singly ionized cobalt cations (Co⁺) in the stability range of CoO.
The uncontrolled use of antimicrobials in veterinary medicine may result in the presence of their residues in food matrices of animal origin such as milk. The aim of this study was to examine the physicochemical quality and to detect antibiotic residues (β-lactams and tetracyclines) in milk, as their presence has resulted in the rejection of significant quantities of milk for marketing. The study was conducted on 274 milk samples delivered to three milk-processing units located in the suburbs of Algiers and surrounding cities (Blida and Boumerdes). Antibiotic residue detection was performed using a fast screening test (BetaStar® Combo), with a reading result within five minutes. The results indicated that the milk processing industry of Blida had the highest rejected milk volumes (43.4%), followed by Algiers (24%) and Boumerdes (19.1%). Non-compliance of milk acidity was the first cause for milk rejection (47.6 %), followed by the presence of antibiotic residues (26.8%), and incompliance with requirements for density (13.4%) and fat levels (12.2%). The study revealed 22 positive cases (8.03%) of antibiotic residues. Among these, 90.91% were positive for β-lactams, and only 9.09% for tetracyclines. All tetracyclines cases and half of the β-lactams cases were found in the Blida milk processing company, indicating that the good practice of milk production and collection must be strengthened in that company.
Introduction L’hyperoxalurie primitive (HP) est la plus redoutable des maladies lithiasiques, transmise selon le mode autosomique récessif, Liée à une mutation du gène AGT. Il s’agit d’affections rares et souvent graves, engageant alors le pronostic rénal et parfois le pronostic vital. Description Nous rapportons le cas d’une patiente âgée de 37 ans, connue depuis l’âge de 18 ans pour lithiases, admise dans notre service pour la 1 fois pour prise en charge d’une insuffisance rénale après une urétéroscopie pour ablation de calculs rénaux. Méthodes La patiente est connue depuis l’âge de 18 ans pour des lithiases rénales bilatérales secondaire a une tuberculose urinaire confirmée bactériologiquement et traitée 3 ans après le traitement antituberculeux, la patiente a subi une chirurgie bilatérale pour ablation de ses calculs. En 2021, la patiente a bénéficié d’une urétéroscopie pour ablation de calculs rénaux caliciels gauches résiduels avec mise en place d’une sonde JJ.08 jours plus tard, installation d’un syndrome infectieux, de douleurs lombaires gauches et d’une oligurie et une insuffisance rénale sévère. Résultats L’analyse morphologique a conclu à des calculs d’oxalate de calcium. La biopsie rénale était en faveur d’une néphropathie cristalline à probable oxalate de calcium. Les dosages d’acide oxalique et d’acide glycolique sériques avec étude des rapports d’acide oxalique/créatinine et de l’acide glycolique/créatinine, était en faveur d’une hyperoxaliurie primitive, l’étude génétique retrouve une double mutation du gène AGXT et gène COL4A3. Conclusion Du fait de la rareté de l’affection et de la méconnaissance des maladies rénales héréditaires responsables de calculs, il se passe en moyenne 3–5 ans entre les premiers symptômes et le diagnostic. La prise en charge chirurgicale n’est pas à envisager chez les patients HP1 avec lithiase non compliquée. Les techniques endoscopiques micro-invasives doivent être privilégiées. Une revue de la littérature n’a pas retrouvé d’association déjà décrite entre l’hyperoxaliurie primitive et le syndrome d’Alport. Un suivi familial est désormais entrepris.
In this paper, we implement the AdaBoost algorithm to optimize the classifications results of precipitations intensities carried out by One versus All strategy using Support Vector Machine (OvA-SVM). The model developed which combines the AdaBoost algorithm with a multiclass SVM is applied to images from the MSG (Meteosat Second Generation) satellite. Other variants to build multiclass SVMs, such as the OvO-SVM (One versus One SVM), SBT-SVM (Slant Binary Tree SVM) and DDAG-SVM (Decision Directed Acyclic Graph) are also implemented on which we tested the AdaBoost algorithm. The study showed that the AdaBoost algorithm performed better in the case of the OvA-SVM variant compared to the other variants. In order to evaluate the elaborated model, some classification techniques, such as the ECST Enhanced Convective Stratiform Technique (ECST), the SART where the Support vector machine, Artificial neural network and Random forest classifiers are combined, the Convective/Stratiform Rain Area Delineation Technique (CS-RADT) and the Random Forest technique (RFT) are applied. The classification results obtained show that AdaBoost with OvA-SVM (AdaOvA-SVM) presents very interesting performances where the evaluation parameters POD, POFD, FAR, BIAS, CSI and PC indicate the values 95.2%, 12.4%, 14.7%, 0.9, 88.1% and 96.5% respectively. Indeed, the AdaOvA-SVM technique has surpassed the CS-RADT, ECST and RFT techniques. As for the comparison with the SART, we noted that OvA-SVM presents very close results. The same trend was also observed when estimating precipitation. At the end of this study, it is shown that the AdaBoost algorithm performs better on a weak classifier or on a strong classifier operating in an unfavorable environment.
Résumé Introduction Le traitement de l'insuffisance cardiaque (IC) à fraction d’éjection réduite < 40 % (HFrEF) fait appel aux règles hygiéno-diététiques associées aux bêtabloquants, bloqueurs du système rénine-angiotensine BSRA (seuls ou associés au sacubitril) et spironolactone. La Dapagliflozine (inhibiteur du SGLT2) a prouvé son efficacité sur la réduction de la morbimortalité de ces patients. Ses effets sur les paramètres échocardiographiques sont moins connus. Objectif Décrire l'impact de l'ajout de Dapagliflozine au traitement conventionnel sur les paramètres échocardiographiques de patients avec HFrEF < 40 %. Méthode Étude observationnelle, monocentrique non randomisée impliquant des patients HFrEF < 40 % sous traitement de l'IC associé à la Dapagliflozine. Ce groupe a été comparé à une cohorte de 50 patients HFrEF < 40 % sous traitement classique sans Dapagliflozine (pris à partir du registre d'IC de notre centre et dont la prise en charge remonte à avant l'adoption de cette molécule dans les recommandations ESC-2021 de l'IC) pour évaluer l'impact échographique de la Dapagliflozine. Résultats 43 patients âgés de 40 à 68 ans avec HFrEF < 40 % sous Bétabloquant, BSRA, Spironolactone et Dapagliflozine 10 mg/j. La FE moyenne était de 33 % ± 3 (30–39 %), diamètre VGD moyen 64 mm ± 6 (55–71 mm) et strain longitudinal moyen à − 11 % ± 4. Ces patients ont été comparés à une cohorte de 50 patients de même profil sans Dapagliflozine. Après un suivi de 7 mois (5–8 mois) : la FE moyenne est passée à 37 % avec 11 patients FE > 40 % contre 35 % et 5 patients FE > 40 % pour le groupe sans Dapagliflozine (P 0,057), VGD moyen à 61 mm contre 66 mm dans le groupe sans Dapagliflozine (P 0,095), strain longitudinal moyen à − 14 % (6 patients < − 15) contre − 12 % (1 patient < − 15) dans le groupe sans Dapagliflozine (P 0,046). Conclusion Au sein d'une population de patients HFrEF < 40 % sous traitement classique de l'insuffisance cardiaque, la prescription de Dapagliflozine est associée à une amélioration des paramètres échographiques (FE et strain longitudinal).
There is no consensus regarding the classification of optic neuritis, and precise diagnostic criteria are not available. This reality means that the diagnosis of disorders that have optic neuritis as the first manifestation can be challenging. Accurate diagnosis of optic neuritis at presentation can facilitate the timely treatment of individuals with multiple sclerosis, neuromyelitis optica spectrum disorder, or myelin oligodendrocyte glycoprotein antibody-associated disease. Epidemiological data show that, cumulatively, optic neuritis is most frequently caused by many conditions other than multiple sclerosis. Worldwide, the cause and management of optic neuritis varies with geographical location, treatment availability, and ethnic background. We have developed diagnostic criteria for optic neuritis and a classification of optic neuritis subgroups. Our diagnostic criteria are based on clinical features that permit a diagnosis of possible optic neuritis; further paraclinical tests, utilising brain, orbital, and retinal imaging, together with antibody and other protein biomarker data, can lead to a diagnosis of definite optic neuritis. Paraclinical tests can also be applied retrospectively on stored samples and historical brain or retinal scans, which will be useful for future validation studies. Our criteria have the potential to reduce the risk of misdiagnosis, provide information on optic neuritis disease course that can guide future treatment trial design, and enable physicians to judge the likelihood of a need for long-term pharmacological management, which might differ according to optic neuritis subgroups.
The study of the shear strength parameters of mixtures comprising tire-derived aggregates (TDA) and clay was the main objective of this experimental work. The tests were performed using the direct shear box. First, the test was performed on specimens comprising only clay in its natural state and then on mixtures consisting of clay and TDA in increasing contents. A total of four samples (natural clay and natural clay with 2, 4, and 6% tire-derived aggregates)) were made and tested at three normal stress levels (100, 200, and 300 kPa). Then, Mohr-Coulomb failure envelopes were drawn to determine the internal friction angle and cohesion for all mixes. The results were compared to find the optimum TDA content and to study the stress-strain behavior of the mixtures. It was observed that mixing TDA up to 6% by weight with clay significantly changes the shear strength, and the internal friction angle increases from 27.47 to 59.39º (an increase of 46.25%). However, the cohesion significantly decreases from 45 to 26 kPa (a decrease of 57.77%). On the other hand, it was observed that increasing the TDA content reduces the density and increases the shear strength of the mixtures. Also, the addition of TDA increases the mixture consolidation and deformation level at failure.
Background and objectives: Science education developed historically from experimentation science to model theories of cognition. Digitization in medical science brought about new challenges of access to science for education and publishing. The aims of our study are to describe the differences in access to science and scientific publications for junior doctors and neurologists in French-speaking countries, and to identify difficulties and their association with demographic, workplace, social and personal factors. Methods: We performed a thirty-nine-question-survey to define access to science from two major perspectives, scientific education, and scientific publishing. We explored scientific education through demographic data and scientific resources (institutional, online, personal), and evaluated scientific publishing of thesis and articles according to demographic data, number of publications, and difficulties with publishing. Results: Our study identified personal and environmental factors interfering with scientific access, some of which are attributed to junior doctors and neurologists in French-speaking countries as age, gender, ethnicity, income and work and life-balance. A heavier load was observed for African scientists. The main scientific resources used for medical education were Journals 82,9%, Congresses 79,4%, and Sci-Hub 74,5%. Junior scientists are facing major difficulties in writing in science due to linguistic (56,5%), financial (64,7%), scientific (55,3%), and logistic (65,3%) factors. Conclusions: This paper suggests that ethnicity, age, gender, and work-life balance can all impact access to science at different levels. The challenge now is to create digital platforms that modernize medical education and help build bridges for research within diverse scientific communities.
Cancer is a major health problem and the second leading cause of death in the world. Modern therapies for cancer may not be accessible to patients from developing countries due to unavailability, cost, and adverse effects. Medicinal plants as alternative medicine thus become the choice of treatment given their therapeutic properties, including in Algeria, where plant based traditional medicine is frequently used to treat several cancers. To examine the use of medicinal plants as treatment for cancer by the Algerian population, the present study conducted an ethnobotanical survey. This study identified eight plant species used to treat different types of cancer including lung, blood, breast, ovarian, uterine, otorhinolaryngologic (ORL), prostate and liver cancer. The most important species used to treat these cancers were: Ephedra alata, Anabasis articulata, Taraxacum officinale and Calligonum comosum, with Anabasis articulata and Calligonum comosum being reported for the first time to treat different types of cancers. Leaves were the most commonly used part of the plant, while decoction was the main method of preparation, and oral administration was the main mode of intake. Findings from the present study suggest that the local population from different regions in Algeria maintain full knowledge about medicinal plants used for cancer treatment, particularly lung cancer. These findings highlight the need to document and preserve the traditional medicine in managing cancer. This may give more insight into future pharmacological investigations on the identified plants to determine their efficacy and safety, which would inform wider scale treatment, thereby increasing global utility.
In this paper, damage detection, localization and quantification are performed using modal strain energy change ratio (MSEcr) as damage indicator combined with a new optimization technique, namely slime mould algorithm (SMA) developed in 2020. The SMA algorithm is employed to assess structural damage and monitor structural health. Two structures, including a laboratory beam and a bar planar truss are considered to study the effectiveness of the proposed approach. Another recent algorithm called marine predators algorithm (MPA) is also used for comparison purposes with SMA. The MSEcr is utilized in the first stage to predict the location of the damaged elements. Single and multiple damages cases are analysed based on different number of modes to study the sensitivity of the proposed indicator to the total number of modes considered in the analysis. Next, this indicator is used as an objective function in a second stage to solve the inverse problem using SMA and MPA for damage quantification of the elements identified in the first stage. Experimental validation is conducted using a 3D frame structure with four stories that have damaged components. It is demonstrated that the proposed approach, using MSEcr and SMA, provides superior results for the considered structures. The effectiveness of this technique is tested by introducing a white Gaussian noise with different levels, namely 2% and 4%. The results show that the provided approach can predict the location and level of damage with high accuracy after introducing the noise.
In the present work, a multicomponent protocol has been described for the synthesis of various benzylpyrazolyl-coumarin 5a-i structures, involving the reaction of 4-hydroxycoumarin, ethyl acetoacetate, hydrazine hydrate, and aldehydes, using an ethanol-water (1:1) mixture as the reaction medium and sodium dodecylbenzenesulfonate (SDBS) as the catalyst. This new approach has advantages such as short reaction time, recovery of the catalysts after the catalytic reaction and their reuse without loss of activity, as well as the lightening of the process. The structures of the obtained benzylpyrazolylcoumarins were determined and confirmed by melting point, ¹H NMR and ¹³C NMR. The determination of antioxidant activity of the obtained benzylpyrazolylcoumarin 5a-i derivatives was studied using the DPPH scavenging assay. Molecular modeling studies using DFT (density function theory) calculations showed that there are six tautomeric structures A to F in which structure C is more stable than the others.
Analysis and modeling of photovoltaic (PV) solar cells and modules based on experimentally measured data are critical for optimizing their design. The need for new algorithms to optimize the PV parameters, many of which owe their inspiration to the metaheuristic search concepts, is still a principal subject of interest and discussion. In this paper, an optimization algorithm that simulates the identity formation behavior of adolescents in the peer group, namely the adolescent identity search algorithm (AISA), was applied to identify the unknown parameters of PV models. In AISA, the updating process proceeds in the exploitation and exploration stages as follows. First, the new best position is generated by identifying and imitating the best identity features of a selected peer from the group to accelerate the exploitation process and produce better performance using a dynamic selection strategy. Second, any locally optimal solution is avoided in the exploration stage for the global optimal solution by adopting the negative/undesirable identity features observed in the peer group. In this context, AISA is applied to identify the unknown parameters of various benchmark test PV models, i.e., single-diode, double-diode, and PV module models. Obtained results showed that this algorithm performed very accurately since lower values of root mean square errors (RMSE) are achieved (9.8602×10-4,2.4251×10-3,1.7298×10-3,1.6212×10-2,and6.3666×10-4)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(9.8602\times 10^{-4},2.4251\times 10^{-3},1.7298\times 10^{-3},1.6212\times 10^{-2},\ and\ 6.3666\times 10^{-4})$$\end{document} when compared with other competitor algorithms. Further, a lower RMSE (9.79352834×10-4)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(9.79352834\times 10^{-4})$$\end{document} was obtained in the case of the double-diode model by adapting some parameters ranges. Also, the high closeness between the simulated current–voltage (I–V) curve is achieved by AISA compared with the experimental data.
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1,005 members
Ameur Soltane
  • Department of Electronics
med-oimar (Amar) Mecherri
  • Department of Chemistry
Lamara Hadjou
  • Department of Economics
Smain Hocine
  • Laboratory of Applied Chemistry and Chemical Engineering (LCAGC)
Lahlou Dahmani
  • Department of Civil Engineering
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Address
BP 17 RP, Tizi Ouzou, Algeria
Head of institution
Prof. Ahmed BOUDA
Website
www.ummto.dz