active fault
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The region of Metlaoui (South Atlas of Tunisia) is listed as one of the major seismotectonic zones of the national territory. About 10 major seismic events with moderate magnitude have occurred from the beginning of last century. The event of 7/11/1989 (Ms = 4.4) was undoubtedly the most important. It caused very significant material damage estimated at 224,525,000 Tunisian Dinars. This study uses a mapping tool to define areas with relatively high degrees of hazard and vulnerability. It also seeks to understand the active fault of the seismic events recorded in this region.

Abstract Cryptographic ICs on edge devices for internet-of-things (IoT) applications are exposed to an adversary and threatened by malicious side channel analysis. On-chip analog monitoring by sensor circuits embedded inside the chips is one of the possible countermeasures against such attacks. An on-chip monitor circuit consisting of a successive approximation register (SAR) analog-to-digital converter (ADC) and an input buffer acquires a wideband signal, which enables to detects an irregular noise due to an active fault injection and a passive side channel leakage analysis. In this paper, several countermeasures against security attacks utilizing wideband on-chip monitors are reviewed. Each technique is implemented on a prototype chip, and the measurement results prove they can effectively detect and diagnose the security attacks.

There is currently an increasing demand for electric vehicles that require greater autonomy and energy efficiency when driving them. Control strategies in energy recovery systems are crucial to optimize the amount of energy returned to the battery and to ensure safety and stability for the user. In this paper, active fault tolerant control systems (AFTC) and passive fault tolerant control systems (PFTC) with other specialized control strategies (Fuzzy Logic, Neural Networks and Perturbation Rejection Controllers) are compared with classical PID controllers.The results of the simulations show that, keeping the battery voltage constant, returns of about 12% of the battery charge capacity are achieved while the braking time of the vehicles is reduced.

The Flight Control System (FCS) is considered as the brain of an aerial vehicle. It is a mechanism through which pilot’s commands are transferred to the actuators of the aircraft control surfaces. In order to ensure safety and increase reliability of aerial vehicles, development of fault tolerant FCSs has been the focus of research community for past few decades. Fault tolerant ability enables an aircraft to maintain satisfactory performance even in the state of a fault. Fault Tolerant Control Systems (FTCS) are categorized as passive and active control systems. Passive FTCS are designed to mitigate the effects of certain known faults. These faults can be related to sensor failure, actuator failure, or system component failure. On the other hand, active FTCS contain a controller reconfiguration mechanism, whereby, they can adjust the controller input online to mitigate the effects of the faults. In this way, they can accommodate complicated and versatile faults as compared to their passive counterparts. This paper presents a review of significant research during last decade in active fault tolerant control with applications to FCSs. A review of state-of-the-art works in this domain has also been presented. Upon review, these state-of-the-art research interests have been categorized into respective categories. Furthermore, research works have been cataloged based on their technology readiness levels. Based on these reviews, future research directions have also been highlighted.

The present paper deals with an active fault-tolerant speed tracking of a five-phase permanent magnet synchronous motor with currents and speed sensor failures. The active fault tolerant control scheme, integrating a sliding mode observer and backstepping controllers, is proposed to provide a continuous drive operation of the five-phase permanent magnet synchronous motor, even during more than one sensor fault occurrence. The sliding mode observer is designed to generate the residual signal necessary for the detection stage, whereas speed and current backstepping controllers handle the operation of the five-phase permanent magnet synchronous motor thanks to their ability to consider the nonlinearities of the system model in generating a control law that is robust enough in healthy and faulty cases. Furthermore, the FTC strategy uses the information received from the fault-tolerant switching block in terms of the measured and the observed currents and speed signals. To gain the maximum benefit of the sliding mode observer’s robustness to random noises and its ease of implementation, the observed currents and speed of the five-phase permanent magnet synchronous motor have been estimated. The simulation results are conducted to show the effectiveness of the proposed FTC control scheme and to prove its high performance in fault detection and tolerant control for the five-phase permanent magnet synchronous motor, since it significantly outperforms the performance provided by traditional methods.

Abstract. We present the content and scripting of an active tectonic lab session conceived for third-year undergraduate students studying Earth sciences at Observatoire des Sciences de l'Univers in Lyon. This session is based on a research project conducted on the submarine Roseau active fault in the Lesser Antilles. The fault morphology is particularly interesting to map as this structure in the deep ocean is preserved from weathering. Thus, high-resolution models computed from remotely operated vehicle (ROV) videos provide exceptional educational material to link fault morphology and coseismic displacement. This class includes mapping exercises on geographical information systems and virtual fieldwork to provide basic understanding of active tectonics and active fault morphology in particular. The work has been conducted either in a full remote configuration via 3D online models or in virtual reality (VR) in a dedicated room using the Minerve software. During the VR sessions, students were either alone in the VR environment or participated as a group that included the instructor (physically in the classroom or remotely from another location), which is to our knowledge one of the first attempts of this kind in France. We discuss the efficiency of virtual fieldwork using VR based on feedback from teachers and students. We conclude that VR is a promising tool to learn observational skills in Earth sciences, subject to certain improvements that should be possible in the years to come.

Turkey has always been exposed to active fault lines passing through and unpredictable seismic activities. These ground movements have always been one of the important issues in our country, which have led to great destruction and loss of lives and property in its past. For this reason, our earthquake regulations, which aim to design more accurately against earthquake movements, are continuously made improvements. In this study, the analysis of structures built with tunnel formwork system which is popular today with the new earthquake regulations entered into force in 2018, and the strength and cost according to the old earthquake regulation in terms of what differences will occur. In addition to the study, we investigated how the number of floors and regular floor plans affects the results. For this purpose, two types of structures were covered with 5, 10, and 15 storey models created, first in the 2007 earthquake regulation; then, in the 2018 earthquake regulation, design analysis was carried out. As a result, the new earthquake regulation, which came into force in 2018, led to more realistic results as it provides more accurate environmental inputs used in design analysis. Earthquake loads affecting floors increased by 3.9% for 5 storey in regular structures, decreasing by 38.4% for 10 stories and 43.3% for 15 stories. More irregular structures increased 7.3% for 5 storey, 10-storey structures decreased by 38.9%, and 15-storey structures decreased by 43.6%. In terms of cost, there was a 0.07% increase in total cost in 5-storey buildings, 2.45% in 10-storey buildings, and a 3.91% reduction in 15-storey buildings. In addition to these results, an empirical formula that estimates m2 prices depending on the number of floors was obtained.

The article deals with the creation of an information and analytical platform for assessing external causes of technogenic (man-made) accidents and for improving methods of their predication and prevention on the territories of long-term geological, mining, and engineering activities on the Southeastern (SE) Transbaikal region example — one of the key areas for mining and extraction of the strategic raw minerals in Russia. 3D modeling of active geological structures and hazardous seismogeodynamic processes on GIS-based technologies is a key instrument for forecasting dangerous natural and technogenic events and risk reduction of their occurrence. A matter of minimizing consequences of natural and technogenic disasters for such facilities of increased technological and environmental hazards as minefields, radiochemical facilities, sites for spent nuclear material disposal, dams, gas and oil pipelines, etc. has become essential. It is necessary to assess modern geodynamic territory’s activity on a unified geoinformation platform applying the newest integrated geological-geophysical researches’ methods for these objects, to select seismically active fault-fracture zones, to determine the rate and direction of surface displacement, to establish patterns of subsoil stressed-strained state natural component influence on behavior of local technogenic processes. Taking into account the specificities of geotectonic structure of mining territories, the structure of monitoring seismogeodynamic processes network on multifunctional geodynamic test sites should be developed. Observations made on test sites form the information basis for forecasting of lithosphere condition, taking decisions on rational subsurface management and providing ecological safety of the territory.