This work deals with the performance improvement study of the direct torque control (DTC) of induction Motor (IM) based on Fuzzy Second Order Sliding Mode Control (FSOSMC). Direct torque control using conventional Second Order Sliding Mode Control regulators has certain disadvantages such as significant flux, torque ripples and sensitivity to parametric variations. To overcome these drawbacks, we apply a new type with more robust regulators such as the fuzzy second order sliding mode control. In recent years, Ant Colony Optimization (ACO) algorithm have attracted considerable attention among various modern heuristic optimization techniques. This paper proposes the ant colony optimization algorithm with fuzzy second order sliding mode controller based direct torque control of induction motor to enhance the system performance and stability. Simulation results demonstrate the feasibility and validity of the proposed DTC-FSOSMC system by effectively accelerating system response, reducing torque and flux ripple and a very satisfactory performance has been achieved.

This work deals with the study and performance improvement of the direct power control of DFIG based on backstepping Controller. Direct power control using hysteresis regulator has certain disadvantages such as significant powers ripples, variable switching frequency and sensitivity to parametric variations. To surmount these disadvantages, we present a robust controller such as the backstepping-based direct power control using SVM. A comparison study was made between the classic direct power control and the backstepping controller. The simulation results show that the backstepping controller provides good results reduces powers ripples.

The direct power control of the doubly fed induction generator using conventional controllers is characterized by unsatisfactory performance: high ripples of stator powers and sensitivity to parametric variations. Among the most evoked control strategies adopted in this field to overcome these drawbacks presented in classical drive, it is worth mentioning the use of the higher law sliding mode developed on the super twisting algorithm associated with the fuzzy logic control in order to realize optimal command performance, Finally, the efficiency of the envisaged control scheme, is investigated against. The proposed regulation scheme is efficient in reducing the powers ripples; successfully suppress chatter and the effects of parametric variations that do not affect the performance of the regulation.

In the petroleum industry, equipments must be maintained properly to meet the adequate reliability standards in order to achieve the desired business goals in terms of productivity, safety and environmental protection. This article offers a new approach focused on risk analysis to select a better maintenance strategy. The proposed approach consists of three stages. In the first step, we identify the accident scenarios that could lead to the loss of production and damage to the environment. In the second step, we estimate the frequency of occurrence of these scenarios. In the third step, we calculate the economic losses and environmental taxes. Finally, an appropriate maintenance strategy is proposed, taking into account the evaluation results obtained by the previous steps. A case study illustrates the proposed approach and shows that the latter constitutes an important decision support tool to improve the existing maintenance strategy to comply with regulations and standards in term of productivity, reduction of costs and environmental protection.

In the petroleum industry, equipments must be maintained properly to meet the adequate reliability standards in order to achieve the desired business goals in terms of productivity, safety and environmental protection. This article offers a new approach focused on risk analysis to select a better maintenance strategy. The proposed approach consists of three stages. In the first step, we identify the accident scenarios that could lead to the loss of production and damage to the environment. In the second step, we estimate the frequency of occurrence of these scenarios. In the third step, we calculate the economic losses and environmental taxes. Finally, an appropriate maintenance strategy is proposed, taking into account the evaluation results obtained by the previous steps. A case study illustrates the proposed approach and shows that the latter constitutes an important decision support tool to improve the existing maintenance strategy to comply with regulations and standards in term of productivity, reduction of costs and environmental protection.

Workplace accidents (WAs) are and will remain a major concern for organizations’ managers. Their control requires putting in place a prevention strategy framed by several factors (human / social, economic, regulatory ...). The successful implementation of this strategy is conditioned on the ground, by the junction of three essential stages, namely: the analysis, evaluation and control of WAs. These three stages are interdependent where a successful control of an action plan is conditioned by a thorough assessment of an accident risk criticality. The latter depends on a good analysis of the accident. Indeed, a good analysis of WAs largely conditions their prevention strategy and that is why the analysis of WAs occupies a prominent place in such strategies. WAs analysis is conducted using appropriate models referred to as "WAs analysis models". Among those cited in the literature, we quote the model 24 that is a contemporary and more systematic model compared to other models. In this context that this article fits in, which aims to highlight its multiple contributions for the analysis of WAs.

The workplace, and more particularly the healthcare sector, has recently experienced a staggering increase in violence. These aggressive behaviors are resulting in considerable consequences on healthcare workers, both in terms of mental and physical health. In light of this observation, this study aims to provide a quantitative analysis of the potential causes leading to violence in Algerian hospitals, which have become the place where tensions arise, especially during these uncertain times caused by the COVID-19 pandemic. Therefore, we started with conducting a field survey, in order to highlight the main causes behind this violence, as well as the strategy in terms of how it is managed as a risk. Then we used ISHIKAWA diagrams to classify predefined causes into several categories and anticipate the likelihood of such violent behaviors. Finally, the results of this study revealed that working conditions were the main cause of violence in Algerian hospitals. In order to remedy this gap, we recommend improving the healthcare staff well-being, as well as prioritizing proactive measures preventing violent behaviors.

The Safety Instrumented System (SIS) is an automated system used to implement one or more safety instrumented functions. A SIS, like the Emergency Shutdown (ESD) system, consists of any combination of sensor(s), safety PLC(s) and final element(s) (e.g. ESD valves). ESD valves are the last line of defense against risks, although the ESD valve has high performance, the data (based on expert judgment and OREDA database) indicates that ESD valves failures are the most critical in the ESD systems. In order to improve the reliability and safety of these valves, we applied the FMEDA diagnostic technique. We started with a decomposition of the ESD valve to the subsystems and we identified their functions. Then we described the failure modes, their mechanisms, their sites and their effects. Then we identified the impact of each failure mode according to the criticality classes and identified the failure rates and their class according to the criticality and the detectability by automatic diagnosis of each mode and from the failure rates we calculated the Safe Failure Fraction (SFF) and Safety Integrity Level (SIL) required and we concluded that the actuator subsystem is the most critical system. Finally, we proposed preventive and protective measures to eliminate or reduce the risk of failure.

In the industry, automated inspection is important for ensuring the high quality and allows acceleration of procedures for quality control of parts or mechanical assemblies. Although significant progress has been made in precision machining of complex surfaces, precision inspection of such surfaces remains a difficult problem. Thus the problem of the conformity of the parts of complex geometry is felt more and more. Motivated by the need to increase quality and reduce costs, and supported by the progress made in the field of it as well as the automation of production which in recent years has seen a considerable evolution in all these stages: from design to control through manufacturing. Due to, we used a 3D computer aided inspection technique on a physical gear using a coordinate measuring machine equipped with a “PC-DMIS” measurement and inspection software. Our work consists in developing a procedure for inspection for reproduction of gear profile by reconstruction of a circle involute gear from a cloud point’s measurement. In order to obtain a reliable result. In this works, we design the CAD-model of the part as accurately as possible (using a mathematical model) and matched with the 3D points cloud that represents the measurement that obtained from scanner. we compare the measurement cloud points from coordinate measurement machine with the mathematical model of construction by ICP (Iterative Closest Point) methods in order to obtain a conformed result and to show the impact of the dimensional inspection and geometric.

In recent years the development of health science to improve people’s lives and reduce the death rate from cardiovascular disease, researchers have invested in the solution of stents to treat cardiovascular disease. Usually a permanent implant (metal stent) is used to treat a temporary disease, effective on elastic recoil and negative remodeling, but promoting intimate proliferation. This is combated by an active stent, which nevertheless induces chronic inflammation and delayed healing (because of active drugs), with the risk of late thrombosis. The idea of resolution leads to the study of the behavior of temporary stent biodegradable and bioresorbable, once the healing process is completed. The purpose of this study is to reduce the disadvantages of metal stents, to do this; a biodegradable material (polylactic acid) is used. The fatigue behavior of a stent after its placement using geometric parameters selected from clinical cases (diastole and systole). A finite element numerical study in the field of biomaterial fatigue is proposed in order to investigate and understand the biodegradable behavior of the stent. The results of the numerical study show the predicted lifetime of the biodegradable fragrance.