Dynamic modelling of the behaviour of the quarkiss earthen dam under seismic loads

The dynamic modelling of the behaviour of the Ouarkiss earthen dam under seismic loads was performed using the finite elements method (FEM), with an approach in effective stresses. The soil behaviour is described by the Mohr-Coulomb criterion. A numerical method and a procedure of analysis are presented in this work. The seismic response of an earthen dam was evaluated. Particular emphasis is placed on the calculation of stresses, displacements, deformations and interstitial overpressures recorded during the seismic solicitation. It has been shown that numerical simulation is able to highlight the fundamental aspects of the displacements and deformations processes experienced by the structure ofdam and to produce preliminary results for the evaluation of the seismic behaviour of the structure taking into account the physical non-linearity of the materials constituting the body of the dam and the effect of the rigidity of the different zones of the dam and the foundation

Yield spread as a leading indicator of Tunisian industrial production

Can the yield spread, which has been found to predict with surprising accuracy the movement of key macroeconomic variables of developed countries, also predict such variables for an emerging country. This paper is an attempt to answer empirically this question for the Tunisian economy. It also examines international financial linkages and how the euro area yield curve helps to predict domestic macro financial variables. Although the phenomenon has been widely examined in developed market economies, similar studies are virtually absent in the case of emerging economies. In part, this is because in developing economies with administrated interest rates, the yield curve has been either completely absent or not market determined and thus did not form a suitable test case. In the Tunisian financial market, there has been considerable improvement in terms of volumes, variety of instruments, numbers of participants and dissemination of information, and a yield curve particularly in case of government securities started emerging since 2000.In our study, two approaches are implemented. The first one, widely used, consists in regressing the growth rate of the coincident indicator on the leading indicator. In the second one, we examine the usefulness of the yield spread in predicting whether or not the economy will be in recession in the future. So, in that particular case we use a Probit model. For both approaches we use the in-sample forecasting ability as well as the out-of-sample accuracy of the outcomes.The results are somewhat tentative but consistent with the similar studies conducted in case of other countries. Findings of the study provide evidence that the yield curve could be considered as a leading indicator of real growth or recessions in Tunisian context, and consequently may be useful for both to private investors and to policy makes for forecasting purposes and, perhaps more importantly to understand the ongoing process of international financial integration

HuntGPT: Integrating Machine Learning-Based Anomaly Detection and Explainable AI with Large Language Models (LLMs)

Machine learning (ML) is crucial in network anomaly detection for proactive threat hunting, reducing detection and response times significantly. However, challenges in model training, maintenance, and frequent false positives impact its acceptance and reliability. Explainable AI (XAI) attempts to mitigate these issues, allowing cybersecurity teams to assess AI-generated alerts with confidence, but has seen limited acceptance from incident responders. Large Language Models (LLMs) present a solution through discerning patterns in extensive information and adapting to different functional requirements. We present HuntGPT, a specialized intrusion detection dashboard applying a Random Forest classifier using the KDD99 dataset, integrating XAI frameworks like SHAP and Lime for user-friendly and intuitive model interaction, and combined with a GPT-3.5 Turbo, it delivers threats in an understandable format. The paper delves into the system's architecture, components, and technical accuracy, assessed through Certified Information Security Manager (CISM) Practice Exams, evaluating response quality across six metrics. The results demonstrate that conversational agents, supported by LLM and integrated with XAI, provide robust, explainable, and actionable AI solutions in intrusion detection, enhancing user understanding and interactive experience

Experimental Validation of a Marine Current Turbine Simulator: Application to a Permanent Magnet Synchronous Generator-Based System Second-Order Sliding Mode Control

This paper deals with the experimental validation of a Matlab-Simulink simulation tool of marine current turbine (MCT) systems. The developed simulator is intended to be used as a sizing and site evaluation tool for MCT installations. For that purpose, the simulator is evaluated within the context of speed control of a permanent magnet synchronous generatorbased (PMSG) MCT. To increase the generated power, and therefore the efficiency of an MCT, a nonlinear controller has been proposed. PMSG has been already considered for similar applications, particularly wind turbine systems using mainly PI controllers. However, such kinds of controllers do not adequately handle some of tidal resource characteristics such as turbulence and swell effects. Moreover, PMSG parameter variations should be accounted for. Therefore, a robust nonlinear control strategy, namely second-order sliding mode control, is proposed. The proposed control strategy is inserted in the simulator that accounts for the resource and the marine turbine models. Simulations using tidal current data from Raz de Sein (Brittany, France) and experiments on a 7.5-kW real-time simulator are carried out for the validation of the simulator.Thèse financée par Brest Métropole Océan

Experimental Validation of a Marine Current Turbine Simulator: Application to a Permanent Magnet Synchronous Generator-Based System Second-Order Sliding Mode Control

This paper deals with the experimental validation of a Matlab-Simulink simulation tool of marine current turbine (MCT) systems. The developed simulator is intended to be used as a sizing and site evaluation tool for MCT installations. For that purpose, the simulator is evaluated within the context of speed control of a permanent magnet synchronous generatorbased (PMSG) MCT. To increase the generated power, and therefore the efficiency of an MCT, a nonlinear controller has been proposed. PMSG has been already considered for similar applications, particularly wind turbine systems using mainly PI controllers. However, such kinds of controllers do not adequately handle some of tidal resource characteristics such as turbulence and swell effects. Moreover, PMSG parameter variations should be accounted for. Therefore, a robust nonlinear control strategy, namely second-order sliding mode control, is proposed. The proposed control strategy is inserted in the simulator that accounts for the resource and the marine turbine models. Simulations using tidal current data from Raz de Sein (Brittany, France) and experiments on a 7.5-kW real-time simulator are carried out for the validation of the simulator.Thèse financée par Brest Métropole Océan

Monochromatic Infrared Photo Energy versus Low Level Laser Therapy in Patients with Knee Osteoarthritis

Introduction: Knee osteoarthritis (KO) is the most common joint disease for which there is no optimal treatment. Monochromatic infrared photo energy (MIPE) is a relatively new light modality used to reduce pain and increase circulation. Low Level Laser Therapy (LLLT) is another light modality used to reduce pain in KO.Methods: The aim of this study was to compare the effects of the MIPE and LLLT in improving pain and function in KO. Sixty participants with KO completed the program and were randomly assigned into two groups. Group 1 (experimental, n=30) received MIPE and exercises. Group 2 (control, n=30) received LLLT and exercises. Both groups received two visits per week for six weeks. Outcome included pain intensity measured on a visual analogue scale and physical function measured with the lower extremity functional scale, before and after the 12 therapy sessions (6 weeks after the start of the intervention).Results: There were statistically significant improvements in pain intensity and lower extremity functional scale scores (p<0.05) in each group. However, no significant differences were recorded between the groups (p>0.05). Conclusion: Therefore, MIPE and LLLT reduce pain and improve function in KO; however, there are no differences between the two modalities in reducing pain and increasing physical function in KO