Dspace UFAS1

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  Caractérisation Théorique et Expérimentale d’un Spectromètre de Neutrons à Barrière de Surface

  (Université Sétif 1 - Ferhat ABBAS , Faculté des Sciences, 2019) BENZAID , Djelloul; SEGHOUR , Abdeslam Encadrant

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  Les R eseaux de Capteurs sans Fil dans l'Internet des Objects

  (Setif 1 University - Ferhat ABBAS , Faculty of Sciences, 2019) HAMMOUDI , Sarra; ALIOUAT , Zibouda Supervisor

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  With the emerging technology of the Internet of Things (IoT), a huge number of intelligent devices are being connected to the Internet. Wireless Sensor Networks and Cloud computing are the main elements that facilitate the emergence of IoT. Sensors storage capacity and power consumption are among the main challenging issues in IoT. The 2.4 GHZ band autho- rizes many di erent wireless technologies to exploit the same spectrum, which yields a severe interference environment. The IEEE 802.15.4 proposed the Time Slotted Channel Hopping (TSCH) designed for low-power and lossy networks (LLNs). The TSCH aims to improve the reliability of sensed data transmission by adapting the channel hopping technique to alle- viate the external interference. Because channels can be a ected by Wi-Fi signals, hopping blindly from one channel to another may also deteriorate the data transmission performance. To solve this problem, we propose a new strategy dedicated to TSCH that makes sensors intelligent and enables them to hop channels in a wise manner. TSCH uses shared links to increase the networks' throughput. To ensure collision avoidance in the presence of hidden nodes, this thesis proposes two intelligent algorithms : Time Slotted Channel Hopping with Correct Collision Avoidance backo algorithm(TSCH-CCA) and Enhanced Priority Channel Access Backo Algorithm(E-PCA), applied respectively to both normal packets and critical events packets. Our proposed solution shows signi cant improvements in terms of latency, network congestion, network lifetime, critical event packets lifetime, and collision avoidance. We also proposed two algorithms that overcome the external interference and multi-path fading. These algorithms are called : Enhanced Time Slotted Channel Hopping (E-TSCH) and Reliable Time Slotted Channel Hopping (R-TSCH). To evaluate their performance, we implemented them in Network Simulator 3 (NS3) and compared them to TSCH. The results show signi cant improvements in terms of the retransmitted packets number, packet delivery ratio, and energy consumption. We also proposed three IaaSs on Cloud servers that seek to ensure Load Balancing, minimize the clients latency and provide a fault tolerant system by ensuring critical data availability and achieving fast input and output critical requests.

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  Assessing the Impact of User-Generated Content on Algerian Consumers' Purchase Intention

  (Setif1 University Ferhat ABBAS , Faculty of Economics , Business and management Sciences , Department of commercial sciences, 2026-09-10) BELAIDI, Nesrine

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  This study aims to examine the influence of social media User-Generated Content (UGC) on Algerian consumers’ purchase intention in the cosmetic industry and to assess the mediating role of positive emotions in this relationship. It also examines the effects of the main UGC dimensions, namely perceived credibility, informativeness, and perceived usefulness, on positive emotions and purchase intention. A quantitative approach was adopted through a survey distributed to 186 Algerian consumers who follow cosmetic-related content on social media. The collected data were analyzed using Structural Equation Modeling (SEM) to test the study hypotheses. The results showed that UGC had a significant effect on Algerian consumers’ purchase intention, and that positive emotions played an important mediating role in this relationship. Among the UGC dimensions, perceived usefulness and informativeness showed stronger effects on positive emotions, while perceived credibility had a direct effect on consumers’ purchase intention. The findings also revealed that income level was the only demographic variable that produced significant differences in the model. The study concludes by offering practical recommendations for cosmetic brands in Algeria on how to use user-generated content more effectively in their digital marketing strategies.

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  Etude mathématique de quelques problèmes en mécanique de contact

  (Université Sétif 1 - Ferhat ABBAS , Faculté des Sciences, 2019) BACHMAR ,Aziza; SERRAR , T. Encadrant

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  The subject of this thesis is the mathematical study of some problems at contact limits in a dynamic or quasistatic process with boundary conditions, for which we couple both the damage of the material and the wear and the effect thermal or electrical. Thermo-elasto-viscoplastic, thermo-viscoelastic and electro-viscoelastic constitutive laws are considered. For each problem we obtain the variational formulation, then we establish the existence results and the uniqueness of the weak solution. The proofs are based on the results of nonlinear evolution inequalities of first orde, parabolic variational equations and inequalities and fixed point arguments

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  The Impact of advertising trust and perceived value on online sales performance.

  (Setif1 University Ferhat ABBAS , Faculty of Economics , Business and management Sciences , Department of commercial sciences, 2026-09-10) BELALIAT, Safa

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  This study examines the impact of advertising trust and perceived value on online sales performance, with a particular focus on users of the Yassir application in the city of Sétif. The research aims to analyze how consumers’ trust in online advertisements and their perceived value of services influence purchase behavior, purchase intention, and customer satisfaction and loyalty. To achieve the objectives of the study, the descriptive analytical method was adopted. A questionnaire was designed as the main tool for data collection and distributed electronically to a convenience sample of 101 Yassir application users. The collected data were analyzed using the Statistical Package for Social Sciences (SPSS V.26), relying on several statistical methods, including frequencies, percentages, arithmetic means, standard deviations, Cronbach’s Alpha, regression analysis, Independent Sample T-test, and One-Way ANOVA. The study focused on three main variables: advertising trust represented by perceived credibility, advertising engagement, and advertising transparency; perceived value represented by monetary value, functional value, and overall value evaluation; and online sales performance represented by purchase behavior, purchase intention, and customer satisfaction and loyalty. The findings revealed that respondents generally showed high levels of agreement regarding the dimensions of advertising trust and perceived value. The results also indicated that advertising trust and perceived value have a statistically significant positive effect on online sales performance. In addition, the study highlighted the important role of credibility, transparency, and perceived benefits in enhancing consumer purchasing decisions and strengthening customer loyalty in digital environments. The study concludes that organizations operating in e-commerce and digital service sectors should focus on building trustworthy advertisements and delivering superior value to consumers in order to improve online sales performance and achieve sustainable competitive advantage.

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