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Dragoni, Michele, and Emanuele Lorenzano. "Conditions for the occurrence of seismic sequences in a fault system." Nonlinear Processes in Geophysics 23, no. 6 (November 16, 2016): 419–33. http://dx.doi.org/10.5194/npg-23-419-2016.
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Abstract. We consider a fault system producing a sequence of seismic events of similar magnitudes. If the system is made up of n faults, there are n! possible sequences, differing from each other for the order of fault activation. Therefore the order of events in a sequence can be expressed as a permutation of the first n integers. We investigate the conditions for the occurrence of a seismic sequence and how the order of events is related to the initial stress state of the fault system. To this aim, we consider n coplanar faults placed in an elastic half-space and subject to a constant and uniform strain rate by tectonic motions. We describe the state of the system by n variables that are the Coulomb stresses of the faults. If we order the faults according to the magnitude of their Coulomb stresses, a permutation of the first n integers can be associated with each state of the system. This permutation changes whenever a fault produces a seismic event, so that the evolution of the system can be described as a sequence of permutations. A crucial role is played by the differences between Coulomb stresses of the faults. The order of events implicit in the initial state is modified due to changes in the differences between Coulomb stresses and to different stress drops of the events. We find that the order of events is determined by the initial stress state, the stress drops and the stress transfers associated with each event. Therefore the model allows the retrieval of the stress states of a fault system from the observation of the order of fault activation in a seismic sequence. As an example, the model is applied to the 2012 Emilia (Italy) seismic sequence and enlightens the complex interplay between the fault dislocations that produced the observed order of events.
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Mizuno, Osamu, Naoki Kawashima, and Kimiaki Kawamoto. "Fault-Prone Module Prediction Approaches Using Identifiers in Source Code." International Journal of Software Innovation 3, no. 1 (January 2015): 36–49. http://dx.doi.org/10.4018/ijsi.2015010103.
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Prediction of fault-prone modules is an important area of software engineering. The authors assumed that the occurrence of faults is related to the semantics in the source code modules. Semantics in a software module can be extracted from identifiers in the module. Identifiers such as variable names and function names in source code are thus essential information to understand code. The naming for identifiers affects on code understandability; thus, the authors expect that they affect software quality. In this study, the authors examine the relationship between the length of identifiers and existence of software faults in a software module. Furthermore, the authors analyze the relationship between occurrence of “words” in identifiers and the existence of faults. From the experiments using the data from open source software, the authors modeled the relationship between the fault occurrence and the length of identifiers, and the relationship between the fault occurrence and the word in identifiers by the random forest technique. The result of the experiment showed that the length of identifiers can predict the fault-proneness of the software modules. Also, the result showed that the word occurrence model is as good a measure as traditional CK and LOC metrics models.
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Kawabata, Kuniyo, Motoharu Tsukada, and Hidemi Tanaka. "Erratum : Occurrence of fault zone materials obtained from Nojima fault by Jet Form Boring（JFB）." Journal of the Geological Society of Japan 111, no. 6 (2005): 369. http://dx.doi.org/10.5575/geosoc.erratum_2005.03.
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Chouiref, Houda, Boumedyen Boussaid, Mohamed Naceur Abdelkrim, Vicenç Puig, and Christophe Aubrun. "Integrated FDI/FTC approach for wind turbines using a LPV interval predictor subspace approach and virtual sensors/actuators." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 235, no. 6 (March 16, 2021): 1527–43. http://dx.doi.org/10.1177/09576509211002080.
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In order to keep wind turbines connected and in operation at all times despite the occurrence of some faults, advanced fault detection and accommodation schemes are required. To achieve this goal, this paper proposes to use the Linear Parameter Varying approach to design an Active Fault Tolerant Control for wind turbines. This Active Fault Tolerant Control is integrated with a Fault Detection and Isolation approach. Fault detection is based on a Linear Parameter Varying interval predictor approach while fault isolation is based on analysing the residual fault signatures. To include fault-tolerance in the control system (already available in the considered wind turbine case study based on the well known SAFEPROCESS benchmark), the information of the Fault Detection and Isolation approach block is exploited and it is used in the implementation of a virtual actuator and sensor scheme. The proposed Active Fault Tolerant Control is evaluated using fault scenarios which are proposed in the wind turbine benchmark to assess its performance. Results show the effectiveness of the proposed Active Fault Tolerant Control approach in faulty situation.
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Zhou, Jun, Xin Li, Rui Liu, and Yingying Liu. "Active fault-tolerant satellite attitude control based on fault effect classification." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 231, no. 10 (August 10, 2016): 1917–34. http://dx.doi.org/10.1177/0954410016662487.
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An active fault-tolerant satellite attitude control scheme based on fault effect classification is presented at the occurrence of faults associated with torques. In this paper, the flexibility and practicability of the fault-tolerant scheme are top priorities. Faults are modeled and divided into additive and multiplicative ones in order to estimate and deal with them specifically and exactly. The additive faults, including additive part of flywheel faults and other uncertain fault torques, are estimated by additive fault estimator and compensated on the basis of nominal controller, whereas the multiplicative faults, denoting torque gain parameter faults of flywheels, are estimated by multiplicative fault estimator and the estimated fault parameters are used for dynamic torque command distribution of flywheels. The final simulation examples and performance comparison of three fault-tolerant schemes show that the proposed scheme based on fault effect classification is an effective, flexible and saving-energy fault-tolerant satellite attitude control scheme. It possesses an engineering value for improving reliability and prolonging on-orbit working lifetime of satellites.
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Roshanravan, Sajad, and Saeed Shamaghdari. "Simultaneous fault detection and isolation and fault-tolerant control using supervisory control technique: asynchronous switching approach." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 234, no. 8 (December 24, 2019): 900–911. http://dx.doi.org/10.1177/0959651819893891.
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This article focuses on the design of a novel active fault-tolerant control scheme based on supervisory control technique for a class of nonlinear systems. This framework relies on a supervisory switching among a finite family of predesigned candidate controllers, which simultaneously performs isolation and accommodation of intermittent faults. This method does not require any additional model or filter bank for fault isolation. Two controller switching algorithms are introduced based on the dwell time and state which are designed especially for this purpose. There is often some time delay between fault occurrence and accommodation. This delay, which is called as the fault detection and isolation delay, causes the asynchronous switching between the system mode and the candidate controller. For the investigation of the stability of the faulty system under asynchronous switching, we explicitly construct piecewise Lyapunov function based on the knowledge of the known Lyapunov function for each operating mode. Then, by using this piecewise Lyapunov function, a new average dwell-time condition is provided on the maximum admissible fault occurrence rate. This condition guarantees the input-to-state stability of the system with respect to the reference signal. The behavior and performance of the proposed fault-tolerant control/fault detection and isolation scheme are demonstrated on the pitch-axis air vehicle model. The hardware-in-the-loop simulation is an important test for the evaluation of the air vehicle autopilot system before flight test. Therefore, the hardware-in-the-loop simulation results are presented to illustrate the effectiveness of the proposed method in the autopilot control loop.
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Kadri, Farid, and Mohamed A. Hamida. "Neural Direct Torque Control for Induction Motor under Voltage Source Inverter Open Switch Fault." Recent Advances in Electrical & Electronic Engineering (Formerly Recent Patents on Electrical & Electronic Engineering) 13, no. 4 (July 5, 2020): 571–79. http://dx.doi.org/10.2174/1874476105666190830103616.
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Background: The study of induction motor behavior during abnormal conditions due to the presence of faults and the possibility to diagnose these abnormal conditions has been a challenging topic for many electrical machine researchers. Objective: Direct Torque Control (DTC) is applied to the control of an induction motor in healthy and an open circuit fault in the PWM three phase voltage fed inverter. Neural DTC is developed and used to improve the dynamic behavior of the drive system under faulty switch occurrence. Methods: The validity of the proposed control scheme is tested under normal conditions and switching fail in the Voltage Source Inverter (VSI) caused by an open circuit. Through a simulation testing of an induction motor drive system at different speed references, a comparison between basic DTC and Neural DTC is performed. Results: Simulated results on 1.5-kW induction motor drive show the performance of the proposed control in normal and faulty cases. The stator current, flux, torque, and speed at different references are determined and compared in the above techniques using MATLAB-SIMULINK. Conclusion: A Neural Network (NN) DTC control system under an open switch fault is proposed without the need for classical switching table. The use of hybrid intelligent techniques aims to improve the DTC performances in case of multiple faults occurrence.
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Ravikumar, C. P., and Nikhil Sharma. "Testability-Driven Layout of Combinational Circuits." VLSI Design 7, no. 4 (January 1, 1998): 347–52. http://dx.doi.org/10.1155/1998/10193.
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The layout of a circuit can influence the probability of occurrence of faults. In this paper, we develop algorithms that can take advantage of this fact to reduce the chances of hard-to-detect (HTD) faults from occurring. We primarily focus on line bridge faults in this paper. We define a bridge fault f as an HTD fault if an automatic test pattern generator fails to generate a test vector for f in a reasonable amount of CPU-time. It is common practice to drop such HTD faults from consideration during test generation. The chip fault coverage achieved by a test set is poor if the fault set consists of many HTD faults. We can combat this problem by avoiding altogether, or by reducing the probability of, the occurrence of HTD faults. In this paper, we consider hard-to-detect bridging faults and show how module placement rules can be derived to reduce the probability of these faults. A genetic placement algorithm that optimizes area while respecting these rules is presented. The placement algorithm has been implemented for standard-cell layout style on a SUN/SPARC and tested against several sample circuits.
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Da Silva, Robson M., Julio Arakaki, Fabricio Junqueira, Diolino J. Santos Filho, and Paulo E. Miyagi. "A Procedure for Modeling of Holonic Control Systems for Intelligent Building (HCS-IB)." Advanced Materials Research 383-390 (November 2011): 2318–26. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.2318.
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Faults occurrence is inevitable in real world and a practical alternative approach is the reduction of fault consequences. Despite of this, the majority of buildings control systems do not have such mechanisms. Thus, this work proposes a procedure for the modeling of control systems for intelligent buildings which considers their functional specifications in normal operation, and in case of faults occurrence. The procedure adopts the concepts of discrete event system, holon, and Petri net and its extensions. It is presented some models derived from case studies, and mechanisms to fault-diagnosis, decision and reconfiguration.
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Spiegel, Gerald, and Albrecht P. Stroele. "Realistic Fault Modeling and Extraction of Multiple Bridging and Break Faults." VLSI Design 7, no. 2 (January 1, 1998): 163–76. http://dx.doi.org/10.1155/1998/83615.
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Fault sets that accurately describe physical failures are required for efficient pattern generation and fault coverage evaluation. The fault model presented in this paper uniquely describes all structural changes in the transistor net list that can be caused by spot defects, including bridging faults that connect more than two nets, break faults that break a net into more than two parts, and compound faults. The developed analysis method extracts the comprehensive set of realistic faults from the layout of CMOS ICs and for each fault computes the probability of occurrence. The results obtained by the tool REFLEX show that bridging faults connecting more than two nets account for a significant portion of all faults and cannot be neglected.
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Amor, Mondher, Taoufik Ladhari, Salim Hadj Said, and Faouzi M’Sahli. "Fault-Tolerant Control for Three-Tank System in Case of Sensor Faults." Mathematical Problems in Engineering 2021 (January 18, 2021): 1–13. http://dx.doi.org/10.1155/2021/8856571.
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This research paper would be devoted to the application of a fault-tolerant control (FTC) for a benchmark system composed of three interconnected tanks in case of sensor faults. The control scheme includes two blocks: fault detection and isolation (FDI) block and a control law reconfiguration block. The strategy of the FDI method is based on a bank of high gain observers; each of them is constructed to estimate the system state vector. Thus, the diagnostic signal-residuals are generated by the comparison of measured and estimated outputs and the faulty sensor is isolated. The reconfiguration block performs an update of the controller parameters according to the operating mode. The application of this method to a pilot plant demonstrates that the hydrographic system maintains quite performances after sensor faults occurrence.
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Namigo, Elistia Liza. "Fault detection using neural network." Journal of Theoretical and Applied Physics 1, no. 1 (February 7, 2017): 70. http://dx.doi.org/10.20961/jotap.v1i1.4718.
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<p class="Abstract">Fault detection technique using neural networks have been successfully applied to a seismic data volume. This technique is basically creating a volume that highlights faults by combining the information from several fault indicators attributes (i.e. similarity, curvature and energy) into fault occurrence probability. This is performed by training a neural network on two sets of attributes extracted at sample locations picked manually - one set represents the fault class and the other represents the non-fault class. The next step is to apply the trained artificial neural network on the seismic data. Result indicates that faults are more highlighted and have better continuity since the surrounding noise are mostly suppressed. </p>
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Namigo, Elistia Liza. "Fault detection using neural network." Journal of Physics: Theories and Applications 1, no. 1 (March 8, 2017): 70. http://dx.doi.org/10.20961/jphystheor-appl.v1i1.4718.
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<p class="Abstract">Fault detection technique using neural networks have been successfully applied to a seismic data volume. This technique is basically creating a volume that highlights faults by combining the information from several fault indicators attributes (i.e. similarity, curvature and energy) into fault occurrence probability. This is performed by training a neural network on two sets of attributes extracted at sample locations picked manually - one set represents the fault class and the other represents the non-fault class. The next step is to apply the trained artificial neural network on the seismic data. Result indicates that faults are more highlighted and have better continuity since the surrounding noise are mostly suppressed.</p>
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Pourazad, Hamed, Javad Askari, and Saeed Hosseinnia. "Isolating observer for simultaneous structural-actuator fault detection." International Journal of Intelligent Unmanned Systems 6, no. 3 (July 2, 2018): 118–33. http://dx.doi.org/10.1108/ijius-09-2017-0011.
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Purpose Increasing commercial applications for small unmanned aircraft create growing challenges in providing safe flight conditions. The conventional measures to detect icing are either expensive, energy consuming or heavy. The purpose of this paper is to develop a fault identification and isolation scheme using unknown input observers to detect and isolate actuator and structural faults in simultaneous occurrence. Design/methodology/approach The fault detection scheme is based on a deviation in system parameters due to icing and lock-in-place (LIP), two faults from different categories with similar indications that require different reconfiguration actions. The obtained residual signals are selected to be triggered by desired faults, while insensitive to others. Findings The proposed observer is sensitive to both actuator and structural faults, and distinguishes simultaneous occurrences by insensitivity to LIP in selected residue signals. Simulation results confirm the success of the proposed system in the presence of uncertainty and disturbance. Research limitations/implications The fault detection and isolation scheme proposed here is based on the linear model of a winged aircraft, the Aerosonde. Moreover, the faults are applied to rudder and aileron in simulations, but the design procedure for other models is provided. The designed scheme could be further implemented on a non-linear aircraft model. Practical implications Applying the proposed icing detection scheme increases detection system reliability, since fault isolation enables timely reconfiguration schemes. Originality/value The observers proposed in previous papers detected icing fault but were not insensitive to actuator faults.
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Mobarak, Youssef Ahmed, and Mahmoud M. Hussein. "Voltage Instability of Initiation Fault Duration as Influenced by Nodes Short Circuit Levels NSCL with Different Types of Loads." International Journal of Electrical and Computer Engineering (IJECE) 6, no. 3 (June 1, 2016): 1305. http://dx.doi.org/10.11591/ijece.v6i3.10163.
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The occurrence of voltage instabilities or voltage collapses depend on the duration of the persistence of the fault and on the type of fault, some faults lead to voltage instabilities, others lead to voltage collapse. Evaluation of fault durations causing occurrence of voltage instabilities is the main goal of this paper. This paper searches for the effect of nodes short circuit levels NSCL and its duration periods initiation of voltage instability, with lagging and leading load power factors at certain loads buses. In this paper, the power system dynamic simulation program is developed for dynamic analysis of voltage stability. This paper is concerned with the fault duration which lead to the occurrence of voltage instability phenomena due to NSCL. The fault which lead to voltage instability is found to be short circuits at certain nodes cleared without any variation in the transmission system elements, i.e. the post-fault conditions will be the same as the pre-fault conditions. Models for loads considered in this study are induction motors with three different shaft mechanical loads, constant impedance CZ loads, constant current CI loads and constant power CP loads are used, as they depict the behavior of most power system loads. The influence of the transmission network impedances, which are nearly the inverse of the NSCL, on the fault duration which lead to the occurrence of voltage instabilities are studied and evaluated using various load representations.<strong><em></em></strong>
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Mobarak, Youssef Ahmed, and Mahmoud M. Hussein. "Voltage Instability of Initiation Fault Duration as Influenced by Nodes Short Circuit Levels NSCL with Different Types of Loads." International Journal of Electrical and Computer Engineering (IJECE) 6, no. 3 (June 1, 2016): 1305. http://dx.doi.org/10.11591/ijece.v6i3.pp1305-1318.
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The occurrence of voltage instabilities or voltage collapses depend on the duration of the persistence of the fault and on the type of fault, some faults lead to voltage instabilities, others lead to voltage collapse. Evaluation of fault durations causing occurrence of voltage instabilities is the main goal of this paper. This paper searches for the effect of nodes short circuit levels NSCL and its duration periods initiation of voltage instability, with lagging and leading load power factors at certain loads buses. In this paper, the power system dynamic simulation program is developed for dynamic analysis of voltage stability. This paper is concerned with the fault duration which lead to the occurrence of voltage instability phenomena due to NSCL. The fault which lead to voltage instability is found to be short circuits at certain nodes cleared without any variation in the transmission system elements, i.e. the post-fault conditions will be the same as the pre-fault conditions. Models for loads considered in this study are induction motors with three different shaft mechanical loads, constant impedance CZ loads, constant current CI loads and constant power CP loads are used, as they depict the behavior of most power system loads. The influence of the transmission network impedances, which are nearly the inverse of the NSCL, on the fault duration which lead to the occurrence of voltage instabilities are studied and evaluated using various load representations.<strong><em></em></strong>
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Kong, Xianguang, Jiantao Chang, Pei Wang, Siyi Gong, Yabin Shi, Yuhang Zhang, and Zekun Guo. "A novel approach of fault-influencing factors analysis for high-voltage switchgears quality supervision based on industrial big data." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 233, no. 14 (April 5, 2019): 2531–46. http://dx.doi.org/10.1177/0954405419839908.
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Fault-influencing factors analysis is an important part of the quality supervision process. There are double functions for high-voltage switchgears that switch off and protect electric circuits in power transmission lines. Such devices have serious impact on power grid–operating efficiency, factory operation, and resident life, which will cause economic losses. As it was difficult for traditional methods to analyze fault-influencing factors accurately and comprehensively, a novel method based on industrial big data was proposed to analyze high-voltage switchgears fault-influencing factors in the process of quality supervision in this article, which integrated the qualitative and quantitative analyses method. In this model, the Classification Based on Multiple Class-Association Rules based on Gaussian Mixture Model as the qualitative analysis method was adapted to analyze the whole life cycle of fault-influencing factors of high-voltage switchgears comprehensively, and supplied fault-influencing factors with discrete interval value ranges. The logistic regression method based on qualitative analysis was constructed to calculate fault occurrence probability quantitatively, including the single-fault occurrence probability and the multiple-faults joint occurrence probability. In addition, the single-fault occurrence probability was used to modify the discrete interval value ranges calculated by the qualitative analysis method, which could make the ranges more accurately. Consequently, the proposed method could provide important reference for high-voltage switchgears operation maintenance, and it would be possible to design accurate maintenance plans before equipment failure. The final instance demonstrates the effectiveness of the proposed methodology.
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Wu, Yang, and Ting Di Zhao. "Time Bayesian Net Fault Prognostics." Applied Mechanics and Materials 610 (August 2014): 350–57. http://dx.doi.org/10.4028/www.scientific.net/amm.610.350.
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As increasing in the number of elements and the complexity of their interactions, fault prognostics faces real challenge to predict faults in a complex system. System fault regularly results from the interaction of component faults performing as logical and timing relationships. We use Bayesian Net to evaluate these logical relations. And the other section of system faults concerns about time sequence of those component faults. Thence, this Bayesian method is expanded to Time Bayesian Net in order to solve this kind of problem. Component fault prognostics is the basis, running dates derived from sensors are applied to analyze status of components in real time. Then a traditional Bayesian Net is constructed according to the mechanism and logical structure of the system. Followed by, exploiting the conclusion from interaction analysis of components, this net is built as a Time Bayesian Net. Afterward, Timed Bayesian Net receives inputs from the outcomes of component fault prognostics, and predicts the type of fault and its time of occurrence through Bayes’ rules.
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Al Kazzaz, Sa’ad Ahmed S., Ibrahim Ismaeel, and Karam Khairullah Mohammed. "Fault detection and location of power transmission lines using intelligent distance relay." International Journal of Power Electronics and Drive Systems (IJPEDS) 11, no. 2 (June 1, 2020): 726. http://dx.doi.org/10.11591/ijpeds.v11.i2.pp726-734.
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The aim of this paper is to design a three-phase distance relay using an adaptive neuro-fuzzy inference system algorithm (ANFIS). The proposed relay is used to protect the power transmission lines where they are subjected to faults continuously. These faults may produce a high electric current which leads to high damage in power system equipment. The relay is used to detect the transmission line faults by measuring the voltage and current values for each phase. The line impedance is then calculated to detect the faults and issue instantaneous trip signal to circuit breaker, to separate the fault zone of the transmission line without affecting the work of other relays. To isolate the faulty line without affecting the other lines within the network the relays were trained using adaptive neuro-fuzzy inference system (ANFIS). The obtained results through this work show that the designated distance relay with (ANFIS) algorithm has the ability to detect the faults occurrence, recognize it from the cases of the disturbance and to isolate only the fault zone without affecting the work of other relays in system.
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Wang, Chu-Tong, Jason S. H. Tsai, Chia-Wei Chen, You Lin, Shu-Mei Guo, and Leang-San Shieh. "An Active Fault-Tolerant PWM Tracker for Unknown Nonlinear Stochastic Hybrid Systems: NARMAX Model and OKID-Based State-Space Self-Tuning Control." Journal of Control Science and Engineering 2010 (2010): 1–27. http://dx.doi.org/10.1155/2010/217515.
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An active fault-tolerant pulse-width-modulated tracker using the nonlinear autoregressive moving average with exogenous inputs model-based state-space self-tuning control is proposed for continuous-time multivariable nonlinear stochastic systems with unknown system parameters, plant noises, measurement noises, and inaccessible system states. Through observer/Kalman filter identification method, a good initial guess of the unknown parameters of the chosen model is obtained so as to reduce the identification process time and enhance the system performances. Besides, by modifying the conventional self-tuning control, a fault-tolerant control scheme is also developed. For the detection of fault occurrence, a quantitative criterion is exploited by comparing the innovation process errors estimated by the Kalman filter estimation algorithm. In addition, the weighting matrix resetting technique is presented by adjusting and resetting the covariance matrix of parameter estimates to improve the parameter estimation for faulty system recovery. The technique can effectively cope with partially abrupt and/or gradual system faults and/or input failures with fault detection.
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Narzary, Daijiry, and Kalyana C. Veluvolu. "Higher Order Sliding Mode Observer-Based Sensor Fault Detection in DC Microgrid’s Buck Converter." Energies 14, no. 6 (March 12, 2021): 1586. http://dx.doi.org/10.3390/en14061586.
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Fault detection in a Direct Current (DC) microgrid with multiple interconnections of distributed generation units (DGUs) is an interesting topic of research. The occurrence of any sensor fault in the DC microgrid should be detected immediately by the fault detection network to achieve an overall stable performance of the system. This work focuses on sensor fault diagnosis of voltage and current sensors in interconnected DGUs of the microgrid. Two separate higher order sliding mode observers (HOSM) based on model dynamics are designed to estimate the voltage and current and generate the residuals for detecting the faulty sensors in DGUs. Multiplicative single and multiple sensor faults are considered in voltage and current sensors. By appropriate selection of threshold, single and multiple sensor fault detection strategies are formulated. A hierarchical controller is designed to ensure equal sharing of current among the DGUs of the DC microgrid and stabilize the system. Simulations are performed to validate the proposed approach for various configurations of the DC microgrid under various load and off noise conditions.
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Cole, M. O. T., P. S. Keogh, and C. R. Burrows. "Fault-tolerant control of rotor/magnetic bearing systems using reconfigurable control with built-in fault detection." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 214, no. 12 (December 1, 2000): 1445–65. http://dx.doi.org/10.1243/0954406001523416.
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Magnetic bearings now exist in a variety of industrial applications. However, there are still concerns over the control integrity of rotor/magnetic bearing systems and the ability of control systems to cope with possible faults that can occur during operation. Unless control systems can be developed that have the ability to maintain safe operation when the system is in a degraded or faulty state, then many, otherwise viable, magnetic bearing applications will remain unfulfilled. In this paper, a method is proposed for the design of a fault-tolerant control system that can detect and identify both incipient and sudden faults as and when they occur. A multivariable H∞ controller is reconfigured on occurrence of a fault so that stability and performance is maintained. A neural network is trained to identify faults associated with the system position transducer measurements so that the output from the neural network can be used as the decision tool for reconfiguring control. In this way, satisfactory control of the system can be maintained during failure of a control input. The method requires no knowledge of the system dynamics or system disturbances, and the network can be trained on-line. The validity of this method is demonstrated experimentally for various modes of sensor failure.
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Changyan Zhou and R. Kumar. "Computation of Diagnosable Fault-Occurrence Indices for Systems With Repeatable Faults." IEEE Transactions on Automatic Control 54, no. 7 (July 2009): 1477–89. http://dx.doi.org/10.1109/tac.2009.2022093.
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Wang, Yuefei, Ang Gao, Sulu Zheng, and Xueyuan Peng. "Experimental investigation of the fault diagnosis of typical faults in reciprocating compressor valves." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 230, no. 13 (June 24, 2015): 2285–99. http://dx.doi.org/10.1177/0954406215592921.
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The failure of suction/discharge valves is the most common cause of unscheduled compressor shutdowns; therefore, the in-time fault diagnosis of valves is crucial to the reliable operation of reciprocating compressors. Major valve faults include leakage, valve flutter, delayed closing, and improper lift. To determine the features for diagnosing these typical valve faults, this paper presents an experimental study of the fault diagnosis of reciprocating compressor valves with acoustic emission technology and simulated valve motion. The measured AE signals and simulated valve motions of normal and failed valves are studied. The results of the fault diagnosis indicate that an earlier occurrence of the suction process can diagnose suction valve leakage and that an earlier occurrence of the discharge process can be used for detecting discharge valve leakage. The leakage also causes an increase in the amplitude of the continuous acoustic emission signal. Valve faults resulting from improper valve lift can be diagnosed by the amplitude of the burst acoustic emission signal. The number of burst acoustic emission signals and the shape of the simulated valve motion can be used to monitor the valve flutter conditions. The location where the valve closes can diagnose a valve-delayed closing fault.
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Anyaka, Boniface Onyemaechi, and Innocent Onyebuchi Ozioko. "Transmission line short circuit analysis by impedance matrix method." International Journal of Electrical and Computer Engineering (IJECE) 10, no. 2 (April 1, 2020): 1712. http://dx.doi.org/10.11591/ijece.v10i2.pp1712-1721.
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Fault analysis is the process of determining the magnitude of fault voltage and current during the occurrence of different types of fault in electrical power system. Transmission line fault analysis is usually done for both symmetrical and unsymmetrical faults. Symmetrical faults are called three-phase balance fault while unsymmetrical faults include: single line-to-ground, line-to-line, and double line-to-ground faults. In this research, bus impedance matrix method for fault analysis is presented. Bus impedance matrix approach has several advantages over Thevenin’s equivalent method and other conventional approaches. This is because the off-diagonal elements represent the transfer impedance of the power system network and helps in calculating the branch fault currents during a fault. Analytical and simulation approaches on a single line-to-ground fault on 3-bus power system network under bolted fault condition were used for the study. Both methods were compared and result showed negligible deviation of 0.02% on the average. The fault currents under bolted condition for the single line-to-ground fault were found to be 4. 7244p.u while the bus voltage is 0. 4095p.u for buses 1 and 2 respectively and 0. 00p.u for bus 3 since the fault occurred at this bus. Therefore, there is no need of burdensomely connecting the entire three sequence network during fault analysis in electrical power system.
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Youngs, Robert R., Walter J. Arabasz, R. Ernest Anderson, Alan R. Ramelli, Jon P. Ake, David B. Slemmons, James P. McCalpin, et al. "A Methodology for Probabilistic Fault Displacement Hazard Analysis (PFDHA)." Earthquake Spectra 19, no. 1 (February 2003): 191–219. http://dx.doi.org/10.1193/1.1542891.
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We present a methodology for conducting a site-specific probabilistic analysis of fault displacement hazard. Two approaches are outlined. The first relates the occurrence of fault displacement at or near the ground surface to the occurrence of earthquakes in the same manner as is done in a standard probabilistic seismic hazard analysis (PSHA) for ground shaking. The methodology for this approach is taken directly from PSHA methodology with the ground-motion attenuation function replaced by a fault displacement attenuation function. In the second approach, the rate of displacement events and the distribution for fault displacement are derived directly from the characteristics of the faults or geologic features at the site of interest. The methodology for probabilistic fault displacement hazard analysis (PFDHA) was developed for a normal faulting environment and the probability distributions we present may have general application in similar tectonic regions. In addition, the general methodology is applicable to any region and we indicate the type of data needed to apply the methodology elsewhere.
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Chao, Kuei-Hsiang, Long-Yi Chang, and Fu-Qiang Xu. "Smart Fault-Tolerant Control System Based on Chaos Theory and Extension Theory for Locating Faults in a Three-Level T-Type Inverter." Applied Sciences 9, no. 15 (July 30, 2019): 3071. http://dx.doi.org/10.3390/app9153071.
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This study proposes a smart fault-tolerant control system based on the theory of Lorenz chaotic system and extension theory for locating faults and executing tolerant control in a three-level T-type inverter. First, the system constantly monitors the fault states of the 12 power transistor switches of the three-level T-type inverter; if a power transistor fails, the corresponding output phase voltage waveform is converted by a Lorenz chaotic system. Chaos eye coordinates are then extracted from a scatter diagram of chaotic dynamic states and considered as fault characteristics. The system then executes fault diagnosis based on extension theory. The fault characteristic value is used as the input signal for correlation analysis; thus, the faulty power transistor can be located and the fault diagnosis can be achieved for the inverter. The fault-tolerant control system can maintain the three-phase balanced output of the three-level T-type inverter, thereby improving the reliability of the motor drive system. The feasibility of the proposed smart fault-tolerant control system was assessed by conducting simulations in this study, and the results verified its feasibility. Accordingly, after the occurrence of the fault in power switches, the balanced three-phase output line voltage remained unchanged, and the quality of the output voltage was not reduced by using the integration of the proposed fault diagnosis system and fault-tolerant control system for a three-level T-type Inverter.
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Mu, Wenying, and Baotong Cui. "Actuator Fault Detection and Accommodation in Distributed Parameter Systems." Open Electrical & Electronic Engineering Journal 9, no. 1 (September 30, 2015): 459–66. http://dx.doi.org/10.2174/1874129001509010459.
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This paper presents a general framework for model-based fault detection and accommodation for a class of distributed parameter systems with control actuator faults. A set of dedicated observers, each with its own time-varying threshold is constructed to detect the occurrence of fault in the corresponding actuator and reduce fault detection time. Additionally, an adaptive diagnostic observer is then designed and analyzed to estimate each individual actuator fault. Based on the online approximation of fault parameter, automated control reconfiguration architecture has been developed to accommodate actuator fault and to preserve closed-loop stability. An example has been discussed using the proposed scheme to demonstrate effectiveness of the method.
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Yetendje, Alain, Maria Seron, and José De Doná. "Robust multisensor fault tolerant model-following MPC design for constrained systems." International Journal of Applied Mathematics and Computer Science 22, no. 1 (March 1, 2012): 211–23. http://dx.doi.org/10.2478/v10006-012-0016-7.
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Robust multisensor fault tolerant model-following MPC design for constrained systemsIn this paper, a robust fault-tolerant control strategy for constrained multisensor linear systems, subject to sensor faults and in the presence of bounded state and output disturbances, is proposed. The scheme verifies that, for each sensors-estimator combination, suitable residual variables lie inside pre-computed sets and selects a more appropriate combination based on a chosen criterion. An active fault tolerant output feedback controller yields an MPC-based control law and, by means of the notion of a "tube" of trajectories, we ensure robust closed-loop exponential stability and good performance in the fault-free case and under the occurrence of abrupt sensor faults.
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Deshkar, Mrunal, and Dipanjali Padhi. "PLC AND HMI FOR CONVEYOR MONITORING AND FAULT DETECTION." International Journal of Advanced Research 9, no. 5 (May 30, 2021): 34–38. http://dx.doi.org/10.21474/ijar01/12805.
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The conveyor is usually used in industries to transport the commodity from one end to another, and can use it anywhere. As the occurrence of faults can affect the entire generation of power, the monitoring and security of these conveyors is important. Using relay logic methods, which have many drawbacks, the safety of the conveyors is carried out, and a new method is therefore required. This paper focuses on the monitoring, control, and safety of conveyors against different types of conveyor faults using a programmable logic controller (plc). This work considers four significant types of faults that commonly occur in conveyors, such as belt sway fault, pull chord fault, zero speed fault, and fire safety.
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Wadas, Sonja H., David C. Tanner, Ulrich Polom, and Charlotte M. Krawczyk. "Structural analysis of S-wave seismics around an urban sinkhole: evidence of enhanced dissolution in a strike-slip fault zone." Natural Hazards and Earth System Sciences 17, no. 12 (December 19, 2017): 2335–50. http://dx.doi.org/10.5194/nhess-17-2335-2017.
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Abstract. In November 2010, a large sinkhole opened up in the urban area of Schmalkalden, Germany. To determine the key factors which benefited the development of this collapse structure and therefore the dissolution, we carried out several shear-wave reflection-seismic profiles around the sinkhole. In the seismic sections we see evidence of the Mesozoic tectonic movement in the form of a NW–SE striking, dextral strike-slip fault, known as the Heßleser Fault, which faulted and fractured the subsurface below the town. The strike-slip faulting created a zone of small blocks ( < 100 m in size), around which steep-dipping normal faults, reverse faults and a dense fracture network serve as fluid pathways for the artesian-confined groundwater. The faults also acted as barriers for horizontal groundwater flow perpendicular to the fault planes. Instead groundwater flows along the faults which serve as conduits and forms cavities in the Permian deposits below ca. 60 m depth. Mass movements and the resulting cavities lead to the formation of sinkholes and dissolution-induced depressions. Since the processes are still ongoing, the occurrence of a new sinkhole cannot be ruled out. This case study demonstrates how S-wave seismics can characterize a sinkhole and, together with geological information, can be used to study the processes that result in sinkhole formation, such as a near-surface fault zone located in soluble rocks. The more complex the fault geometry and interaction between faults, the more prone an area is to sinkhole occurrence.
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Yıkılmaz, M. B., E. M. Heien, D. L. Turcotte, J. B. Rundle, and L. H. Kellogg. "A fault and seismicity based composite simulation in northern California." Nonlinear Processes in Geophysics 18, no. 6 (December 14, 2011): 955–66. http://dx.doi.org/10.5194/npg-18-955-2011.
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Abstract. We generate synthetic catalogs of seismicity in northern California using a composite simulation. The basis of the simulation is the fault based "Virtual California" (VC) earthquake simulator. Back-slip velocities and mean recurrence intervals are specified on model strike-slip faults. A catalog of characteristic earthquakes is generated for a period of 100 000 yr. These earthquakes are predominantly in the range M = 6 to M = 8, but do not follow Gutenberg-Richter (GR) scaling at lower magnitudes. In order to model seismicity on unmapped faults we introduce background seismicity which occurs randomly in time with GR scaling and is spatially associated with the VC model faults. These earthquakes fill in the GR scaling down to M = 4 (the smallest earthquakes modeled). The rate of background seismicity is constrained by the observed rate of occurrence of M > 4 earthquakes in northern California. These earthquakes are then used to drive the BASS (branching aftershock sequence) model of aftershock occurrence. The BASS model is the self-similar limit of the ETAS (epidemic type aftershock sequence) model. Families of aftershocks are generated following each Virtual California and background main shock. In the simulations the rate of occurrence of aftershocks is essentially equal to the rate of occurrence of main shocks in the magnitude range 4 < M < 7. We generate frequency-magnitude and recurrence interval statistics both regionally and fault specific. We compare our modeled rates of seismicity and spatial variability with observations.
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Muhammad, N., H. Zainuddin, E. Jaaper, and Z. Idrus. "An early fault detection approach in grid-connected photovoltaic (GCPV) system." Indonesian Journal of Electrical Engineering and Computer Science 17, no. 2 (February 1, 2020): 671. http://dx.doi.org/10.11591/ijeecs.v17.i2.pp671-679.
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<span>Faults in any components of PV system shall lead to performance degradation and if prolonged, it can leads to fire hazard. This paper presents an approach of early fault detection via acquired historical data sets of grid-connected PV (GCPV) systems. The approach is a developed algorithm comprises of failure detection on AC power by using Acceptance Ratio (AR) determination. Specifically, the implemented failure detection stage was based on the algorithm that detected differences between the actual and predicted AC power of PV system. Furthermore, the identified alarm of system failure was a decision stage which performed a process based on developed logic and decision trees. The results obtained by comparing two types of GCPV system (polycrystalline and monocrystalline silicon PV system), showed that the developed algorithm could perceive the early faults upon their occurrence. Finally, when applying AR to the PV systems, the faulty PV system demonstrated 93.38 % of AR below 0.9, while the fault free PV system showed only 31.4 % of AR below 0.9.</span>
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Mirshekali, Hamid, Rahman Dashti, Karsten Handrup, and Hamid Reza Shaker. "Real Fault Location in a Distribution Network Using Smart Feeder Meter Data." Energies 14, no. 11 (June 1, 2021): 3242. http://dx.doi.org/10.3390/en14113242.
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Distribution networks transmit electrical energy from an upstream network to customers. Undesirable circumstances such as faults in the distribution networks can cause hazardous conditions, equipment failure, and power outages. Therefore, to avoid financial loss, to maintain customer satisfaction, and network reliability, it is vital to restore the network as fast as possible. In this paper, a new fault location (FL) algorithm that uses the recorded data of smart meters (SMs) and smart feeder meters (SFMs) to locate the actual point of fault, is introduced. The method does not require high-resolution measurements, which is among the main advantages of the method. An impedance-based technique is utilized to detect all possible FL candidates in the distribution network. After the fault occurrence, the protection relay sends a signal to all SFMs, to collect the recorded active power of all connected lines after the fault. The higher value of active power represents the real faulty section due to the high-fault current. The effectiveness of the proposed method was investigated on an IEEE 11-node test feeder in MATLAB SIMULINK 2020b, under several situations, such as different fault resistances, distances, inception angles, and types. In some cases, the algorithm found two or three candidates for FL. In these cases, the section estimation helped to identify the real fault among all candidates. Section estimation method performs well for all simulated cases. The results showed that the proposed method was accurate and was able to precisely detect the real faulty section. To experimentally evaluate the proposed method’s powerfulness, a laboratory test and its simulation were carried out. The algorithm was precisely able to distinguish the real faulty section among all candidates in the experiment. The results revealed the robustness and effectiveness of the proposed method.
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Sun, Xiaozhe, Xingjian Wang, and Siru Lin. "Multi-Fault Diagnosis Approach Based on Updated Interacting Multiple Model for Aviation Hydraulic Actuator." Information 11, no. 9 (August 26, 2020): 410. http://dx.doi.org/10.3390/info11090410.
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The aviation hydraulic actuator (HA) is a key component of the flight control system in an aircraft. It is necessary to consider the occurrence of multiple faults under harsh conditions during a flight. This study designs a multi-fault diagnosis method based on the updated interacting multiple model (UIMM). The correspondence between the failure modes and the key physical parameters of HA is found by analyzing the fault mode and mechanism. The key physical parameters of HA can be estimated by employing a series of extended Kalman filters (EKF) related to the different modes of HA. The models in UIMM are updated once the fault is determined. UIMM can reduce the number of fault models and avoid combinatorial explosion in the case of multiple faults. Simulation results indicate that the multi-fault diagnosis method based on UIMM is effective for multi-fault diagnosis of electro-hydraulic servo actuation system.
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Idris, Muhd Hafizi, Mohd Rafi Adzman, Hazlie Mokhlis, Mohammad Faridun Naim Tajuddin, Haziah Hamid, and Melaty Amirruddin. "Two-terminal fault detection and location for hybrid transmission circuit." Indonesian Journal of Electrical Engineering and Computer Science 23, no. 2 (August 1, 2021): 639. http://dx.doi.org/10.11591/ijeecs.v23.i2.pp639-649.
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This paper presents the algorithms developed to detect and locate the faults ata hybrid circuit. First, the fault detection algorithm was developed using the comparison of total positive-sequence fault current between pre-fault and fault times to detect the occurrence of a fault. Then, the voltage check method was used to decide whether the fault occurred at overhead line (OHL) or cable section. Finally, the fault location algorithm using the impedance-based method and negative-sequence measurements from both terminals of the circuit were used to estimate the fault point from local terminal. From the tests of various fault conditions including different fault types, fault resistance and fault locations, the proposed method successfully detected all fault cases at around 1 cycle from fault initiation and with correct faulted section identification. Besides that, the fault location algorithm also has very accurate results of fault estimation with average error less than 1 km and 1%.<br /><div> </div>
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Ertuncay, Deniz, and Giovanni Costa. "Determination of near-fault impulsive signals with multivariate naïve Bayes method." Natural Hazards 108, no. 2 (April 29, 2021): 1763–80. http://dx.doi.org/10.1007/s11069-021-04755-0.
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AbstractNear-fault ground motions may contain impulse behavior on velocity records. To calculate the probability of occurrence of the impulsive signals, a large dataset is collected from various national data providers and strong motion databases. The dataset has a large number of parameters which carry information on the earthquake physics, ruptured faults, ground motion parameters, distance between the station and several parts of the ruptured fault. Relation between the parameters and impulsive signals is calculated. It is found that fault type, moment magnitude, distance and azimuth between a site of interest and the surface projection of the ruptured fault are correlated with the impulsiveness of the signals. Separate models are created for strike-slip faults and non-strike-slip faults by using multivariate naïve Bayes classifier method. Naïve Bayes classifier allows us to have the probability of observing impulsive signals. The models have comparable accuracy rates, and they are more consistent on different fault types with respect to previous studies.
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Donnelly, Laurance. "Chapter 17 Mining-induced fault reactivation in the UK." Geological Society, London, Engineering Geology Special Publications 29, no. 1 (2020): 425–32. http://dx.doi.org/10.1144/egsp29.17.
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AbstractFaults are susceptible to reactivation during coal mining subsidence. The effects may be the generation of a scarp along the ground surface that may or may not be accompanied by associated ground deformation including fissuring or compression. Reactivated faults vary considerably in their occurrence, height, length and geometry. Some reactivated faults may not be recognizable along the ground surface, known only to those who have measured the ground movements or who are familiar with the associated subtle ground deformations. In comparison, other reactivated faults generate scarps up to several metres high and many kilometres long, often accompanied by widespread fissuring of the ground surface. Mining subsidence-induced reactivated faults have caused damage to roads, structures and land. The objective of this chapter is to provide a general overview of the occurrence and characteristics of fault reactivation in the UK.
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GLUKHOV, Anton, and Petr TIKHOMIROV. "Erguveem Ore Region in the eastern Chukotka Peninsula: An effect of the tectonics of the ore-bearing volcano-structures on composition of the gold-silver mineralization." Domestic geology, no. 3-4 (September 14, 2021): 52–59. http://dx.doi.org/10.47765/0869-7175-2021-10022.
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The geological and structural position of the Pepenveem and Korrida Au-Ag ore occurrences situated in the East-Chukotka segment of the Okhotsk-Chukotka Volcanogenic Belt (OCVB) was studied. The Pepenveem ore occurrence was characterized by one (volcanogenic) mineralization stage. It is localized within a graben-like monocline composed of Late Cretaceous volcanics. A relatively stable tectonic regime caused rather low temperature and pressure gradients during the ore formation and, consequently, simple mineral composition of the ores and absence of advanced argillic alteration. In contrast, the Korrida ore occurrence was characterized by two (volcanogenic and plutonogenic) mineralization stages. It is localized within a plutonogenic uplift complicated by a regional fault zone. Here, the basement of the volcano-structure, composed of island-arc volcano-sedimentary rocks, was uplifted to the surface by numerous high-angle faults. The here observed extensive development of zoned metasomatic haloes (including advanced argillic alterations), abundance of mineral species, and sharp temperature and pressure gradients could resulted from tectonic activity in a zone of interaction between the plutonic dome and deep-seated regional fault.
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Leeke, Matthew. "Simultaneous Fault Models for the Generation and Location of Efficient Error Detection Mechanisms." Computer Journal 63, no. 5 (April 30, 2019): 758–73. http://dx.doi.org/10.1093/comjnl/bxz022.
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Abstract The application of machine learning to software fault injection data has been shown to be an effective approach for the generation of efficient error detection mechanisms (EDMs). However, such approaches to the design of EDMs have invariably adopted a fault model with a single-fault assumption, limiting the relevance of the detectors and their evaluation. Software containing more than a single fault is commonplace, with safety standards recognizing that critical failures are often the result of unlikely or unforeseen combinations of faults. This paper addresses this shortcoming, demonstrating that it is possible to generate efficient EDMs under simultaneous fault models. In particular, it is shown that (i) efficient EDMs can be designed using fault injection data collected under models accounting for the occurrence of simultaneous faults, (ii) exhaustive fault injection under a simultaneous bit flip model can yield improved EDM efficiency, (iii) exhaustive fault injection under a simultaneous bit flip model can be made non-exhaustive and (iv) EDMs can be relocated within a software system using program slicing, reducing the resource costs of experimentation to practicable levels without sacrificing EDM efficiency.
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Jeman, Ameerul A. J., Naeem M. S. Hannoon, Nabil Hidayat, Mohamed M. H. Adam, Ismail Musirin, and Vijayakumar V. "Simulation on microgrid connected PV system under balance and unbalance fault." Indonesian Journal of Electrical Engineering and Computer Science 13, no. 3 (March 1, 2019): 1332. http://dx.doi.org/10.11591/ijeecs.v13.i3.pp1332-1336.
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<p><span>This paper presents an analysis in Matlab/Simulink of a three-phase photovoltaic system under balance and unbalance faults in Matlab/Simulink. The aim of this paper is to investigate the performance of the system under various types of fault. The simulation involved various types of faults occurring at different distances from the point of common coupling of the PV system. This paper also aimed to identify what type of fault that may severely damage the system. The simulation results presented in this paper show that the three-phase fault in the microgrid was severely affecting the system since it involved all the three phases of the system while the distance of the fault occurrence is less influenced in the system. The purpose of this research is to observe the effect on the system based on the types of faults occur and the distance faults occur.</span></p>
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Fadil, Hicham, Mohamed Larbi Elhafyani, and Smail Zouggar. "Enhanced Three-Phase Inverter Faults Detection And Diagnosis Approach - Design And Experimental Evaluation." International Journal of Power Electronics and Drive Systems (IJPEDS) 9, no. 2 (June 1, 2018): 559. http://dx.doi.org/10.11591/ijpeds.v9.i2.pp559-570.
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<span lang="EN-US">Efficiency, reliability, high power quality and continuous operation are important aspects in electric vehicle attraction system. Therefore, quick fault detection, isolation and enhanced fault-tolerant control for open-switches faults in inverter driving systems become more and more required in this filed. However, fault detection and localization algorithms have been known to have many performance limitations due to speed variations such as wrong decision making of fault occurrence. Those weaknesses are investigated and solved in this paper using currents magnitudes fault indices, current direct component fault indices and a decision system. A simulation model and experimental setup are utilized to validate the proposed concept. Many simulation and experimental results are carried out to show the effectiveness of the proposed fault detection approach.</span>
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Hu, S. R., J. K. Zhang, K. Liang, and M. Bao. "Deflection Sensors Fault Time Locating Based on Kalman Filtering and Data Fusion." Applied Mechanics and Materials 743 (March 2015): 820–23. http://dx.doi.org/10.4028/www.scientific.net/amm.743.820.
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Traditional research on sensor fault are usually confined to fault space locating, however, it’s very necessary to determine the time that the fault occurrence for subsequent data processing and to guarantee the normal operation of the monitoring system. Therefore, this paper proposes a method of sensors fault time locating. First of all, use Kalman filter to process the sensor data, then define the support level of sliding window correlation to sample correlation, combining with multi sensors data fusion, so as to identify the accurate time point of fault. Combine the deflection sensors data from Caiyuanba bridge, simulating four common faults. The results show that the error of located time is less than the width of the sliding window.
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Zhang, Guowei, and Andrew Hynes. "Fabrics and kinematic indicators associated with the local structures along Finlay – Ingenika fault, McConnell Creek area, north-central British Columbia." Canadian Journal of Earth Sciences 31, no. 11 (November 1, 1994): 1687–99. http://dx.doi.org/10.1139/e94-151.
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Structures associated with dextral transcurrent displacement on the Finlay – Ingenika fault are characterized predominantly by subvertical to vertical faults. Intersections of the fault planes with planar fabrics are all subvertical. This geometry, together with the common occurrence of subhorizontal slickenlines and stretching lineations in some strongly deformed fault zones, indicates their strike-slip nature. Principal directions of the strain ellipsoids determined from the deformed volcanic fragments along one of the faults are in accordance with those of the magnetic susceptibility ellipsoids from the adjacent plutonic rocks, indicating that the plutonic rocks experienced the same deformation as the Late Triassic Takla Group volcanics. Regional cleavage within the fault-bounded blocks indicates that the blocks were nonuniformly rotated clockwise about subvertical axes in response to progressive dextral transcurrent displacement on the Finlay – Ingenika fault. The mode of deformation observed in the area may characterize many parts of the Intermontane Belt.
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Le, Anh Ngoc. "Characterization and Distribution of Cenozoic Polygonal Fault: Case Studies in West Africa and Vietnam Continental Margins." Iraqi Geological Journal 54, no. 1E (May 31, 2021): 19–28. http://dx.doi.org/10.46717/igj.54.1e.2ms-2021-05-23.
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The Cenozoic sequence of offshore Cameroon and Vietnam has been analysed based on newly 1500 km2 3D seismic data (Kribi-Campo basin) and 75 km 2D seismic data (Hoang Sa basin). Polygonal faults are widely developed in both passive margins and have relatively similar characteristics. These highly faulted intervals are up to c. 1000 m, characterized by normal faults with a throw of 10-20 ms TWT and 100 m - 1000 m spacing, displaying a polygonal pattern in the map view. Polygonal faults in the Kribi-Campo basin developed almost in the entire Cenozoic sequence mainly in two sets, one in deep section and one in shallow section whereas the Hoang Sa basin developed the polygonal fault only in the shallow section up to the seafloor corresponding to the Pliocene- Pleistocene sequence. In the Kribi-Campo basin, polygonal faults are developed extensively in the high gradient slope (3.4o) which is relatively rare in the low gradient slope (0.7o). Hoang Sa basin shows the widespread polygonal fault except for the area of canyon occurrence. The occurrence of thick and widespread polygonal fault formations associated with the low amplitude reflections suggests the interpretation of fine-grained sediments, thus possibly great seal potential for the study areas.
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Park, Jiwoon, and Hoyoung Yoo. "Area-Efficient Differential Fault Tolerance Encoding for Finite State Machines." Electronics 9, no. 7 (July 8, 2020): 1110. http://dx.doi.org/10.3390/electronics9071110.
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A differential fault tolerance encoding is presented for finite state machines (FSMs) to improve their area efficiency. As the manufacturing technology for semiconductors continues to scale down, the probability of the occurrence of unexpected faults in integrated circuits has been increasing. Because an FSM controls an entire digital circuit, the faults in FSMs should be carefully addressed. Whereas the previous encoding applies a fault tolerance scheme to all the states in an FSM, the proposed encoding applies a fault tolerance scheme to only specific states depending on their importance. Compared with the previous complete fault tolerance encoding, the proposed encoding provides a comparable failure probability with a small hardware by applying the fault tolerance scheme differently to each state. The proposed method improves the area efficiency by 36.1%, 43.8%, 49.2%, and 74.6% compared with that by the non-fault tolerance, previous hardware redundancy, information redundancy, and time redundancy methods, respectively. Consequently, the proposed method can provide a flexible solution by applying the fault tolerance differently depending on the importance of the states.
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Sun, Shi Guo, Shao Jie Feng, and Jia Hao Lei. "Water-Inrush Mechanism while Fault Zone Secondary Activated in Mining." Advanced Materials Research 524-527 (May 2012): 799–802. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.799.
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As many different size faults in the fully-mechanized sublevel caving mining area overlying rock, undermine the continuity of rock deformation, and the occurrence of different conditions, the impact properties vary widely. This paper studies the impact of faults on the water inrush with specific examples of project, obtained the discontinuous deformation on both sides of fault zone induce the fault zone secondary activate and result in it’s water transmitting ability dramatic increase; with the mining geometry increases, the water flowing-fracture zone height increase and lead to the water conductivity channel of faults connect with rock fracture zone, so as to constitute water inrush channel and likely to cause water inrush accident, so to explore the influence of fault for underground work safety has important theoretical significance and application value.
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Shipilin, Vladimir, David C. Tanner, Hartwig von Hartmann, and Inga Moeck. "Multiphase, decoupled faulting in the southern German Molasse Basin – evidence from 3-D seismic data." Solid Earth 11, no. 6 (November 16, 2020): 2097–117. http://dx.doi.org/10.5194/se-11-2097-2020.
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Abstract. We use three-dimensional seismic reflection data from the southern German Molasse Basin to investigate the structural style and evolution of a geometrically decoupled fault network in close proximity to the Alpine deformation front. We recognise two fault arrays that are vertically separated by a clay-rich layer – lower normal faults and upper normal and reverse faults. A frontal thrust fault partially overprints the upper fault array. Analysis of seismic stratigraphy, syn-kinematic strata, throw distribution, and spatial relationships between faults suggest a multiphase fault evolution: (1) initiation of the lower normal faults in the Upper Jurassic carbonate platform during the early Oligocene, (2) development of the upper normal faults in the Cenozoic sediments during the late Oligocene, and (3) reverse reactivation of the upper normal faults and thrusting during the mid-Miocene. These distinct phases document the evolution of the stress field as the Alpine orogen propagated across the foreland. We postulate that interplay between the horizontal compression and vertical stresses due to the syn-sedimentary loading resulted in the intermittent normal faulting. The vertical stress gradients within the flexed foredeep defined the independent development of the upper faults above the lower faults, whereas mechanical behaviour of the clay-rich layer precluded the subsequent linkage of the fault arrays. The thrust fault must have been facilitated by the reverse reactivation of the upper normal faults, as its maximum displacement and extent correlate with the occurrence of these faults. We conclude that the evolving tectonic stresses were the primary mechanism of fault activation, whereas the mechanical stratigraphy and pre-existing structures locally governed the structural style.
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Belalem, Ghalem, and Said Limam. "Fault Tolerant Architecture to Cloud Computing Using Adaptive Checkpoint." International Journal of Cloud Applications and Computing 1, no. 4 (October 2011): 60–69. http://dx.doi.org/10.4018/ijcac.2011100105.
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Cloud computing refers to both the applications delivered as services over the Internet and the hardware and systems software in the datacenters that provide those services. Failures of any type are common in current datacenters, partly due to the number of nodes. Fault tolerance has become a major task for computer engineers and software developers because the occurrence of faults increases the cost of using resources and to meet the user expectations, the most fundamental user expectation is, of course, that his or her application correctly finishes independent of faults in the node. This paper proposes a fault tolerant architecture to Cloud Computing that uses an adaptive Checkpoint mechanism to assure that a task running can correctly finish in spite of faults in the nodes in which it is running. The proposed fault tolerant architecture is simultaneously transparent and scalable.
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Ben Brahim, Ali, Slim Dhahri, Fayçal Ben Hmida, and Anis Sellami. "Adaptive sliding mode fault tolerant control design for uncertain nonlinear systems with multiplicative faults: Takagi–Sugeno fuzzy approach." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 234, no. 2 (June 24, 2019): 147–59. http://dx.doi.org/10.1177/0959651819857385.
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The present article deals with adaptive sliding mode fault tolerant control design for uncertain nonlinear systems, affected by multiplicative faults, that is described under Takagi–Sugeno fuzzy representation. First, we propose to conceive robust adaptive observer in order to achieve states and multiplicative faults estimation in the presence of nonlinear system uncertainties. Under the nonlinear Lipschitz condition, the observer gains are attained by solving the multi-objective optimization problem. Second, sliding mode controller is suggested to offer a solution of the closed-loop system stability even the occurrence of real fault effects. The main objective is to compensate multiplicative fault effects based on output feedback information. Sufficient conditions are developed with [Formula: see text] performances and expressed as a set of linear matrix inequalities subject to compute controller gains. Finally, simulation results, using the nonlinear model of a single-link flexible joint robot system, are given to illustrate the capability of the suggested fault tolerant control strategy to treat multiplicative faults.