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Classification des défauts des transformateurs électriques par des méthodes d’intelligence artificielle
(2026) AMAR BENSABER Sidi Mohammed Monsef; IZA Lamia Khadra; BOUDJELLA Fatima Zohra
This work focuses on improving the diagnosis of power transformers, which are critical components for
the stability and efficiency of electrical networks. Continuous monitoring of this equipment is essential
to prevent major failures. This research is primarily based on Dissolved Gas Analysis (DGA), an
effective technique for identifying hidden internal faults. In this study, we explored a modern approach
based on artificial intelligence and machine learning. Using a dataset of 709 samples, several
normalization methods were tested. The simulation results indicate that combining Median IQR
normalization with the Bagged Trees model, evaluated through a 5-fold cross-validation, delivers the
highest diagnostic accuracy. Furthermore, an ablation study proved that a complete vector of 5 gases
remains indispensable for maintaining reliable classification, paving the way toward optimal predictive
maintenance for electrical infrastructures.
Simulation du comportement d’une structure soumise à différente type de défaut (fissure/entaille)
(2026) BENSIYAKOUB Azeddine; SOUIDI Kheïreddine; BOUZITOUNA Wahiba Nesrine
Fracture mechanics is a fundamental discipline in mechanical engineering that focuses on the behavior
of materials containing defects or discontinuities. Its primary objective is to understand the mechanisms
of crack initiation and propagation in order to prevent sudden structural failures and enhance the
reliability of engineering components during service. This work first presents the theoretical foundations
of fracture mechanics, including the different fracture modes, the Stress Intensity Factor (K), and the
development of the plastic zone near the crack tip. It also reviews the main analytical approaches used
for notch assessment, such as Pluvinage’s volumetric approach, the equivalent crack concept, and the
Creager–Paris formulation. The study then examines the nature and classification of structural defects,
including cracks, notches, and corrosion damage, while discussing the maintenance and repair techniques
commonly employed in industry. Particular attention is given to bonded composite patch repair, a widely
adopted solution in the aerospace sector for restoring structural integrity and extending service life.
Finally, a three-dimensional numerical investigation is carried out using the Abaqus software package to
evaluate the effectiveness of a Boron/Epoxy composite patch in reinforcing an aluminum plate containing
either a crack or a notch. The study also addresses the simulation of crack growth and fracture path
propagation using the eXtended Finite Element Method (XFEM), providing a deeper understanding of
the behavior and damage tolerance of repaired structures.
Simulation de l’écoulement du fluide dans un compresseur alternatif
(2026) Bensaad Mohamed Mehdi; Belghorzi Djawed; Guendouz Bouhelal
The enhancement of energy efficiency in gas compression systems constitutes a major
industrial challenge, particularly in the refrigeration and energy storage sectors. The present
master's thesis is devoted to the study of the performance of a positive displacement piston
compressor.
A 0D thermodynamic model, incorporating the principal sources of internal losses –
namely thermal, fluidic and mechanical losses – and coupled with a parametric sensitivity
analysis, was developed for this purpose.
The obtained results reveal significant trends, most notably the predominant influence
of the connecting rod length on both the maximum in-cylinder pressure and the volumetric
efficiency. Moreover, the compression work per cycle, evaluated across the various simulated
configurations, proves to be a relevant indicator of the machine's overall energy efficiency.
This work contributes to a deeper understanding of the multiphysics couplings
occurring in piston compressors and provides an accessible predictive tool to support design
decisions. The perspectives arising from this study include experimental validation and the
extension of the model to other compressor architectures.
Contribution à une étude épidémiologique de la fièvre boutonneuse dans la wilaya d’Ain Témouchent
(2026) BENHADDOU Karima Samia; BENHOURA Loubna; BENSAAD Fatima Zahra; MOGHTIT Fatima Zohra
Mediterranean spotted fever (MSF), a zoonotic disease transmitted primarily through
the bite of the brown dog tick (Rhipicephalus sanguineus), continues to pose a significant
public health challenge in Algeria. The aim of this study was to contribute to characterize the
regional epidemiology of MSF in the Wilaya of Aïn Témouchent and to perform a detailed
assessment of the epidemiological, clinical, and hospital-related features of reported cases.
This retrospective descriptive study was conducted using two complementary datasets.
The first comprised 1,128 cases of Mediterranean spotted fever reported by the various
Primary Public Healthcare Facilities in the Wilaya of Aïn Témouchent between January 2021
and December 2025. The second involved a detailed analysis of the clinical and laboratory
characteristics of 50 patients hospitalized at Ahmed Medaghri Hospital in Aïn Témouchent.
The epidemiological analysis demonstrated a substantial increase in MSF incidence in
2023, with 427 reported cases. Women represented 58% of affected individuals, and most
patients were from rural settings (82%). A clear seasonal distribution was observed, with 69%
of infections occurring during the summer period. Epidemiological investigations identified
tick bites (84%) and contact with dogs (78%) as the principal exposure factors. Among
hospitalized patients, the clinical picture was characterized by the typical triad of fever,
maculopapular rash, and an inoculation eschar (tache noire). The most frequent laboratory
abnormalities were thrombocytopenia, leukopenia or leukocytosis, and increased liver
transaminase levels consistent with hepatic cytolysis. Most patients responded well to
doxycycline therapy and experienced favorable outcomes, although a limited number
developed severe disease with multiorgan involvement.
In conclusion, the diagnosis of MSF remains primarily based on clinical findings and
epidemiological history. Early administration of appropriate antibiotic therapy is associated
with a favorable outcome and complete recovery in the vast majority of patients.
Modélisation Mathématique des Populations en Interactions
(2026) LECHLECHE Safaa; BOUKHALFA Fatima
The purpose of this thesis is the mathematical study of the dynamics of interacting
populations. We use ordinary differential equations as the main modeling tool to analyze
the local and global stability of fundamental models of Lotka-Volterra (predator prey),
competition and mutualism, then a system of three populations (rabbits, sheep, wolves).
Then we extend this study to more complex systems integrating the epidemiological di-
mension.