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This paper proposes a credit-driven practical byzantine fault tolerance based on a consensus algorithm for sustainable 6G communication to address the potential threat of malicious activity in green and sustainable 6G-based Industrial Internet of Things (IIoT) applications. The dual-layer architecture allows for simultaneous verification of transactions and the execution of read-write operations. According to simulation studies, CD-PBFT enhances algorithm performance and stability while efficiently reducing validation time. Empirical findings demonstrate that CD-PBFT achieves both efficiency and security fault tolerance by reducing network transaction latency by an average of 34.8% and increasing throughput by 25.2% compared to PBFT. [ABSTRACT FROM AUTHOR]

This paper considers the simultaneous fault-tolerant control and disturbance rejection of impulsive switched linear systems. First, estimates of faults and disturbances in the system can be obtained by designing observers. Then, through the obtained estimation, the controller with anti-interference performance and fault tolerance performance is designed. Under the arbitrary switching rules and the minimum dwell time switching rules, the stability of the system is guaranteed. Finally, the effectiveness of the method is verified by numerical simulation and example simulation. [ABSTRACT FROM AUTHOR]

We here address problems of nonunique paths and poor fault tolerance in the traditional shortest path transfer method and propose an overall adjustment method of relative corrections of master reference stations in BDS/GNSS Network RTK systems. Our method comprehensively considers the vector relationship of baseline error corrections, the baseline closure error of Delaunay triangulation and the interpolation relationship between stations to realize the one-time generation, obtaining all relative error corrections of the master reference station in a network RTK system. The test results showed that our method can achieve a success rate of more than 95% and an incorrect rate of less than 0.01%. The error corrections, generated by the two methods, are verified and analysed by the positioning accuracy of the rover. The results show that the positioning accuracy of the method in this paper is improved by about 17% over the shortest path transfer method. [ABSTRACT FROM AUTHOR]

Blockchain (BC) technology has attracted a lot of interest due to its excellent security and privacy features as well as its immutability. While BC can address security and privacy challenges in IoT, it is often computationally expensive, suffers from limited scalability, and introduces bandwidth overheads and delays, making it unsuitable for IoT applications. This paper proposes a novel lightweight and scalable blockchain (LIGHT-SB) designed specifically for IoT environments. In a smart IoT ecosystem, low-resource devices benefit from a centralized manager that handles communication keys and manages requests. LIGHT-SB enhances decentralization while maintaining robust privacy and security through a hybrid consensus algorithm combining permissionless proof-of-capacity and permissioned Byzantine fault tolerance (PoC-PBFT). Secure message delivery is achieved using SHA-256 and RSA cryptographic techniques. IoT device authentication, communication, and storage are safeguarded within the network. Distributed throughput management is implemented to monitor and adjust BC usage, ensuring it remains efficient. Qualitative evaluations demonstrate that LIGHT-SB effectively mitigates several security threats. [ABSTRACT FROM AUTHOR]

Fault tolerance refers to the ability of a system to continue functioning even if some of its components fail. This concept is fundamental in several domains because reliability and continuous operation are essential in carrying out their functions. Graph embedding means mapping a graph into some other structure that preserves some of the properties or relations held by the original graph. Applications in machine learning, data mining, and network analysis make fault-tolerant embedding of graphs a crucial topic. In this paper, fault-tolerant embeddings are proposed in Archimedean tessellations. The path in the embeddings does not intersect or overlap. [ABSTRACT FROM AUTHOR]

From practical considerations, crisp sensor measurements are associated with tolerance value. Thus, the sensor measurements lead to intervals. Researchers proposed M, F, Ω, and N functions for the fusion of interval-valued sensor measurements. We proved that the F-function provides the worst-case optimal interval estimate given the number of faulty sensors. We generalize the F-function to multi-dimensional intervals. We also propose new results on the attack resilience of fusion functions. Thus, this research paper provides new insights into robust sensor fusion. [ABSTRACT FROM AUTHOR]

The current teaching mode in geometry mainly focuses on two-dimensional levels, and the teaching tools utilized are static and not interactive. This paper proposes the use of a smart pen for three-dimensional geometry experimental teaching and a multimodal intention understanding and human-computer collaboration algorithm for the smart pen. The primary innovations of this paper lie in the development of a smart pen and a virtual platform for geometry education tailored for geometry experimental instruction. This system can promptly perceive and comprehend user behavior in real-time. Furthermore, a standardized topological equivalence model is proposed as the basis for a point selection strategy. By establishing correspondence between the modeled point selection model and the actual operation scene, the behavioral intent imposed on the model is applied to the operation object of the actual scene. Additionally, CNN-based and information entropy-based multimodal fusion intention understanding models are proposed for different input modalities to capture the operational intention of users by fusing their multimodal input data. The algorithm further improves the accuracy rate through an error correction mechanism based on implicit interaction to achieve better human-computer collaboration. The algorithm proposed in this paper has resulted in a 0.47-second improvement in point selection average time and achieved an intent understanding accuracy of 98.21%. This improvement leads to better fault tolerance and fluency during human-computer interaction, reduces the cognitive load on the user, and improves the overall user experience. [ABSTRACT FROM AUTHOR]

Several technologies are implemented for serving industrial information and controlling the process in which the increased complexity and allied fault failed to achieve a reliable transmission to activate the timely network. These data must be transferred from one node to another node without any fault or delay in their nodes. To resolve this problem, an algorithm named SAOA is proposed to communicate the messages from various services without any delay in their nodes. IoT with mobile sink node is simulated in the network based on the MoO4RPL objective and the phases involved in this strategy are topology, route discovery, communication, and route maintenance phase. The topology network is generated for network topology and the rank is computed based on the energy, trust, delay, fault tolerance, and link quality in the multi-objective route discovery phase. In the communication phase, the optimal route is selected using proposed SAOA with fitness function factors. At last, the route maintenance phase is performed, and the proposed SAOA has achieved a minimum distance of 53.807 m, maximum energy of 0.415 J, maximum link quality of 2.163, and maximum trust of 0.701, respectively. In the future, another algorithm is implemented in IoT applications with minimum modifications to evaluate the various metric values. [ABSTRACT FROM AUTHOR]

Evolving as an outperforming nanotechnology, quantum-dot cellular automata (QCA) is being efficiently used for the design and development of digital modules. This paper presents a novel design for an ultra-efficient exclusive-OR (EXOR) gate in QCA nanotechnology using the cell translation technique. The analysis for fault tolerance and power dissipation of the proposed design is also assessed. To establish the effectiveness of the proposed design, an extensive comparison with the existing designs is provided. As a test bench implementation, the proposed EXOR gate is available as a module for the development of a parity checker, a full subtractor, and a 4-input binary to gray (B2G) code converter in QCA. The cell count for the proposed design of the EXOR gate, full subtractor, parity checker, and 4-input B2G converter is 8, 35, 24, and 24, and the total area (µm2) is 0.0039, 0.0259, 0.01749, and 0.0129, respectively. The proposed EXOR gate design outclasses the hitherto prevailing designs both in terms of the operational parameters and the dissipation of energy. The design simulations have been performed in QCA Designer 2.0.3, and the energy dissipation analysis has been executed in QCA Designer-E and QCAPro. [ABSTRACT FROM AUTHOR]

The Internet of Things (IoT) connects billions of devices, but concerns about data security and device identification have grown. This study introduces Proof of IoT (PIoT), a novel consensus method using blockchain-based smart contracts to ensure secure data transfer and device authentication in IoT networks. PIoT employs NuCypher-based security computations for authentication and data updating, ensuring only authorized parties access blockchain-recorded information. A reward-based filtering mechanism identifies malicious nodes, bolstering consensus integrity. Simulations demonstrate PIoT's superior performance compared to conventional methods, showing a 74.7% and 96.8% improvement over LPBFT and DAC4SH Consensus, respectively. PIoT enhances blockchain security under IoT by 15% compared to DAC4SH. Beyond facilitating secure IoT device communication, this approach mitigates various IoT attacks, offering a comprehensive solution to emerging IoT security challenges. ABBREVIATION: DAC4SH, Data access control scheme for smart home; DDoS, Distributed denial of service; DoS, Denial of Service; DTLS, Datagram Transport Layer Security; IoT, Internet of Things; LPBFT, Lightweight Particle Byzantine fault tolerance; MAC, Message authentication code; MITM, Man in the Middle; PBFT, Practical Byzantine Fault Tolerance; PIoT, Proof of IoT; TLS, Transport Layer Security [ABSTRACT FROM AUTHOR]

Byzantine Fault Tolerance (BFT) is crucial for ensuring the resilience of Distributed Machine Learning (DML) systems during training under adversarial conditions. Among the rising corpus of research on BFT in DML, there is no comprehensive classification of techniques or broad analysis of different approaches. This paper provides an in-depth survey of recent advancements in BFT for DML, with a focus on first-order optimisation methods, particularly, the popular one Stochastic Gradient Descent (SGD) during the training phase. We offer a novel classification of BFT approaches based on characteristics such as the communication process, optimisation method, and topology setting. This classification aims to enhance the understanding of various BFT methods and guide future research in addressing open challenges in the field. This work provides the foundations for developing robust BFT systems, using a variety of optimisation methods to strengthen resilience. [ABSTRACT FROM AUTHOR]

Despite the numerous advantages of multilevel inverters over two-level inverter, their main limitation is the increase in component count as the level increases. The increase in component count and high failure rate of power semiconductor switches and capacitors tend to reduce the reliability of multilevel inverters. Thus, the ability of multilevel inverter to tolerate faults is an important factor to consider when choosing a multilevel inverter topology for safety-critical applications. In this regard, the current study presents a new single-source five-level fault-tolerant inverter based on switched capacitor with self-balancing capability. In the proposed inverter, the fault tolerance is achieved with the help of redundant legs. A simple fault reconfiguration strategy is proposed in the present study for the proposed inverter which can retain the number of levels in the output, power handling capacity and self-balancing of switched capacitor in the event of any single switch fault and the most of multi-switch fault scenarios. The simulation study and experimental results validate the suggested inverter's fault tolerant capability under various fault scenarios. A comprehensive and detailed comparison study demonstrates the proposed fault resilient inverter's superiority over the recently proposed fault tolerant multilevel inverter available in the literature. [ABSTRACT FROM AUTHOR]

AbstractWith the development and integration of artificial intelligence (AI) and virtual reality technology, metahuman powered by AI is gradually becoming an important force in service marketing. Considering the novel characteristics of metahuman services, this study aims to identify and validate the core dimensions of the metahuman service quality. Online review analysis, multiple regression analysis, and fuzzy-set Qualitative Comparative Analysis (fsQCA) were employed to analyze data in this study. The results show that nine dimensions of metahuman service quality, including stability, complementary, efficiency, continuous improvement, empathy, accessibility, personalization, cultural sociability, and fault tolerance, significantly contribute to customer satisfaction. Moreover, the results suggest that there are five multiple and equally effective combinations of metahuman service quality dimensions that can achieve high consumers’ satisfaction. This study contributes to the avatar literature by unveiling the complexity behind the adoption of AI-powered avatar. It also offers meaningful practical implications for marketing managers to optimize the combination of metahuman service quality. [ABSTRACT FROM AUTHOR]

Although the change-oriented organizational citizenship behavior (OCB) exhibited by civil servants is crucial for public organizations to swiftly adapt to environmental changes, the formation process of this behavior from a power perspective has been largely ignored. Drawing upon the Situated Focus Theory of Power, this study examines whether, how, and when civil servants' sense of power impacts their change-oriented OCB. Through a combination of two experiments (Study 1 and 2) and a survey (Study 3), we found a positive correlation between civil servants' sense of power and their change-oriented OCB (Study 1). Furthermore, psychological safety plays a mediating role in the above relationship. A fault-tolerant organizational climate moderates the relationship between a sense of power and psychological safety, as well as the mediating role of psychological safety. Specifically, the impact of a sense of power on change-oriented OCB through psychological safety becomes weakened when the organizational climate's fault tolerance is high (Study 2 and 3). These findings provide theoretical and practical insights into how to stimulate the change-oriented OCB of civil servants. [ABSTRACT FROM AUTHOR]

The integrated navigation system ensures maritime autonomous surface ships (MASSs) to safely, efficiently, and autonomously complete various operations in different complex navigation environments. Investigating robust algorithms for integrated navigation is crucial for enhancing the fault tolerance of the system and ensuring the stable and continuous output of the ship's motion state. However, existing research primarily focused on optimising particular filtering algorithms or examining the foundations of information allocation within a predetermined integrated navigation structure. As such, strategies for enhancing the robustness of the MASS integrated navigation system and the design of subsystems for federated filters in the event of navigation sensor failures have not been sufficiently investigated for complex maritime navigation scenarios. Consequently, this research introduces an observability sharing factor accounting for both system characteristics and state estimation performance in integrated navigation systems, employing nonlinear sampling filtering. Subsequently, a robust integrated navigation framework with distributed federal filter is developed. Within this framework, an adaptive federated filtering integrated navigation algorithm is proposed based on the observability sharing factor to allocate information in federated filtering. Finally, both the theoretical correctness and effectiveness of the algorithm were verified through simulations and real-ship experiments to assist with the development of accurate and fault-tolerant maritime navigation systems. [ABSTRACT FROM AUTHOR]

Modern database management is often faced with a high number of concurrent end-users, and the need for database distribution to ensure fault tolerance and high throughput. To flexibly address these challenges, many modern database management systems (DBMS) provide highly automated and effortless, i.e., highly usable database distribution, deployment, and maintenance. However, the usability considerations are yet to extend from the aforementioned DBMS features to query language compilers. In this study, based on participant answers (N = 157), we compare the error message qualities of four modern DBMSs (CockroachDB, SingleStore, NuoDB, and VoltDB) using one objective and three subjective metrics. Our results show that some of the DBMSs provide the users with more useful error messages, even though many of these error messages violate even the most basic usability guidelines. These results (i) are applicable in further developing the usability aspects of query language compilers, (ii) provide a timely effort of bridging the gap between human-computer interaction and query language compilers, and (iii) offer suggestions on teaching novices, who require emphasized support in query formulation. [ABSTRACT FROM AUTHOR]

With the acceleration of the global modern industrialisation process and the increasingly serious environmental problems, the development of low energy consumption, high efficiency electrochemical energy conversion equipment and separation system has become a research hotspot in the scientific and industrial circles. At present, machine learning has become an important research method to explore and expand two-dimensional material family. Traditional experimental and computational methods have low fault tolerance when studying two-dimensional materials, which requires a lot of time and research and development costs. Machine learning, due to its powerful data processing capability and flexible algorithm model, can help reduce the time and cost of discovering and understanding two-dimensional materials, and can effectively predict and expand two-dimensional material systems based on data and explore their potential for experimental synthesis and application. This paper will focus on the methods of machine learning, the exploration of machine learning in 2D material design and synthesis, and the exploration of machine learning in 2D material properties and applications. Finally, this paper uses ML algorithm to test the synthesised polymer. The experimental data points and prediction data points have relatively good consistency with each other, which indicates that ML model can be used as a prediction tool to identify the undeveloped polymer for gas separation. [ABSTRACT FROM AUTHOR]

Based on the data of Chinese A-share listed companies from 2009 to 2017, this paper examines whether or not shareholders tolerate the faults of scientific and technological (S&T) innovation and the effect of firm heterogeneity on this relationship. The empirical results show that, in general, shareholders do not tolerate faults in S&T innovation, and this intolerance intensifies with a longer failure time; there are differences in shareholders' fault tolerance in different types of companies; shareholders of companies with high profitability and financial risk tend to tolerate faults in S&T innovation. This paper might provide some new insights for corporate shareholders to devise reasonable S&T strategies. [ABSTRACT FROM AUTHOR]

Optimal engine torque management, a fundamental objective, depends predominantly on engine speed tracking performance. It ensures to attain desired speed profile in the presence of uncertainties, disturbances and malfunctions. On the other hand, certain requirements such as emissions control, fuel efficiency and drivability are degraded in case of poor speed tracking. Furthermore, constraints on engine speed tracking performance are even more stringent for hybrid power-train architecture as crankshaft speed and engine torque are the basic variables for coordinated control. Speed tracking is also considered essential for gear shift control of the automatic transmission. In this research work, a framework for fault-tolerant speed tracking of the gasoline engine is proposed using the First Principle-based Engine Model (FPEM). A high-fidelity direct relationship between fuel injection input and engine speed is derived by the transformation of FPEM. Fault is induced in the fuel injection subsystem to generate the torque imbalance. Using the proposed framework, a second-order sliding mode-based control technique is applied to track desired speed profile by mitigating the faults in the fuel injection subsystem. Reference data acquired from the engine test rig is used to demonstrate the offline validity and fault tolerance capabilities of the proposed framework in MATLAB/Simulink. [ABSTRACT FROM AUTHOR]

One of the important issues in evaluating an interconnection network is to study the Hamiltonian cycle embedding problems. For a positive integer k, a graph G is said to be spanning k-cyclable if for k prescribed vertices x 1 , x 2 , ... , x k , there exist k disjoint cycles C 1 , C 2 , ... , C k such that the union of C 1 , C 2 , ... , C k spans G, and each C j contains exactly one vertex x j of x 1 , x 2 , ... , x k . According to the definition, the problem of finding hamiltonian cycle focuses on k = 1. The notion of spanning cyclability can be applied to the problem of identifying faulty processors and other related issues in interconnection networks. The n-dimensional augmented cube A Q n is an important node-symmetric variant of the n-dimensional hypercube Q n . In this paper, we prove that A Q n with n ≥ 3 is spanning k-cyclable for 1 ≤ k ≤ 2 n − 4. [ABSTRACT FROM AUTHOR]

This study tackles the fault estimation issue for a continuous-time periodic piecewise time-varying systems (PPTVSs) with delays, fault signal and external disturbances. In particular, the PPTVSs are conjured up by segmenting the fundamental period of the periodic system into a finite number of subintervals. Moreover, fault estimator is designed in line with periodic piecewise observer systems to estimate the immeasurable states of the PPTVSs and the fault signal, simultaneously. Subsequently, in accordance with the estimated values of the fault signal and state dynamics, a fault-tolerant controller is devised. Moreover, by utilising Lyapunov stability theory and matrix polynomial lemma, sufficient criteria are procured in context of linear matrix inequalities to affirm the uniform boundedness of the undertaken system and error system. Further, relying on the acquired constraints, the precise configuration of the fault-tolerant control and observer gain matrices are proffered. Eventually, by offering two illustrative examples including mass-spring-damper system, the utility and potential of presented theoretical insights are validated. [ABSTRACT FROM AUTHOR]

Potentially high-impact disturbances always disrupt normal product use, cause structural or functional failure, and shorten product life. How to design products with better fault tolerance and recovery capabilities to effectively deal with such complex disturbances will be a key factor in product innovation and intelligence in the future. Resilience is a system's ability to rapidly recover to its full function after disruption, and it is applied across multiple industries. As manufacturing systems and products diversify, this has resulted in an increasing variety of different definitions that threatens to dilute the concept and lead to ineffective implementations of resilient product design. This paper reviews the different definitions and scope of application of resilience in existing research and proposes two general definitions of resilient products from broad and narrow perspectives. On this basis, the author compared product resilience with product reliability, robustness, and adaptability, and proposed four main characteristics of product resilience, including visibility, agility, redundancy, and adaptability. Next, a design principle for product resilience is introduced, and future needs and opportunities for product resilience are outlined. [ABSTRACT FROM AUTHOR]

The very-large-scale-integration industry has been highly trying to attain miniaturization. This function causes several challenges regarding size, switching speed, power, and fault-tolerant at the nanoscale. Quantum-dot cellular automata (QCA) can contain a remarkable reduction in scale, fast switching rate, ultra-low energy consumption, and high fault-tolerant. Thus, fault-tolerant logic has attained the attention of several investigators in the QCA science domain. On the other hand, a binary-to-gray converter converts the input data to the gray number to facilitate error correction in digital communication. So, in the present investigation, we have demonstrated a structure of fault-tolerant binary-to-gray converter in QCA employing the majority gate, inverter gate, and cell redundancy on the wire. With the utilization of the QCADesigner 2.0.3 simulator, we have simulated and tested proposed circuits. In this paper, four factors, namely single-cell missing, displacement, misalignment, and extra single-cell, have been inspected by simulation software. The proposed fault-tolerant two-bit, three-bit, and four-bit binary-to-gray converter could attain 100% fault tolerance while a single missing defect existed in the layout. [ABSTRACT FROM AUTHOR]

The of robustness in cloud computing is becoming mainstream due to unprecedented growth in the cloud. In order to enhance cloud service reliability, various fault tolerance techniques have been suggested in the literature. Many cloud service reliability and availability issues are arising due to the failure of virtual machines (VMs). Therefore, this study contributes a new Threshold-Based Adaptive Fault Tolerance (TBAFT) approach in the cloud by amalgamating proactive and reactive approaches. Furthermore, in this paper, VM migration and replication are being utilized in the proactive approach, whereas retry is used as a reactive approach. Additionally, experimental validation is performed by comparing three benchmark fault tolerance approaches by incorporating the first fit and least full host selection policies. The obtained experimental results of the proposed approach are presented in terms of different metrics such as failure rate, throughput, migration, and execution time using CloudSim simulator. [ABSTRACT FROM AUTHOR]

This paper presents a novel Passive Fault Tolerant Control System (PFTCS) for Air Fuel Ratio (AFR) control system of the Internal Combustion (IC) gasoline engine to prevent its shutdown. A Proportional plus Integral (PI) controller with high feedback gain is implemented to control AFR by introducing a fuel throttle valve in the fuel line of the engine. The salient feature of the proposed controller is its less complex structure due to the absence of Analytical Redundancy (AR). Dual redundancy in the hardware is suggested for the sensors to prevent tripping in case of coincident faults in multiple sensors and for the actuator assembly to confiscate a single point of failure. The robustness of the proposed PFTCS is tested by introducing noise in the sensor measurements. MATLAB / Simulink environment simulation results demonstrate that the proposed PFTCS is robust to faults in normal as well as noisy conditions of the sensors without any degradation of AFR. The stability analysis of the proposed controller is performed by determining the poles of the closed-loop system. The reliability analysis of the proposed controller has been performed by calculating the probabilistic reliability function of the model. The comparison of the proposed model with the existing models has also been carried out to elaborate its effectiveness. [ABSTRACT FROM AUTHOR]

Group key management in cloud computing has become a trending topic in recent decades. This paper deals with the implementation of clustered structure based on centralized key management. In a centralized key management scheme, the Key Server is responsible for generating user keys and group keys of the cloud. The proposed work consists of a single Central Server and a number of sub-servers and each sub-server can manage multiple different groups. To achieve fault tolerance, each group is replicated into multiple different sub-servers. Users are allocated to a specific group and the size of the group is limited. Each group has a separate group key to avoid internal attacks and they can communicate through a central server. The proposed work encourages intergroup communication and essentially reduces the computations and storage complexity of the central server. Also, we propose to remove the rekeying process upon a new user joining by maintaining a file access list for each file, which will reduce the impact of the security features that even there is a leakage of the group key after the user leaves. Further, this paper proposes a contributory key management scheme where each member of the group is responsible for generating the group key. [ABSTRACT FROM AUTHOR]

The exchanged 3-ary n-cube E 3 C (r , s , t) , proposed by Lv et al. in 2021, is obtained by removing edges from a 3-ary n-cube Q n 3 , where r + s + t + 1 = n. The topological interconnection network of a multiprocessor system can be modeled as a connected graph. Analyzing the fault tolerance of its topological structure is critical in the course of design and maintenance of it. Given a connected graph G, let F be an edge subset of G. F is called an h-edge-cut of G, if G−F is disconnected and each remaining component has the minimum degree of at least h. The h-edge-connectivity λ h (G) is the minimum cardinality of all h-edge-cuts of G. For 1 ≤ r ≤ s ≤ t and 0 ≤ h ≤ r , in this paper, we determine the 2 h -edge-connectivity of exchanged 3-ary n-cubes, E 3 C (r , s , t) , and prove the exact values λ 2 h (E 3 C (r , s , t)) = 2 ⋅ 3 h (r + 1 − h). [ABSTRACT FROM AUTHOR]

Reliability evaluation of interconnection networks is of significant importance to the design and maintenance of interconnection networks. The component connectivity is an important parameter for the reliability evaluation of interconnection networks and is a generalization of the traditional connectivity. Let g ≥ 0 be an integer and G be a connected graph. A g-component cut of G is a vertex set S such that G−S has at least g components. The g-component connectivity c κ g (G) of G is the size of the smallest g-component cut. Determining the g-component connectivity is still an unsolved problem in many interconnection networks. In this paper, we prove the lower bound of the g-component connectivity of any n-dimensional hypercube-like networks. We also determine the g-component connectivity of varietal hypercubes and crossed cubes which are the members of hypercube-like networks. As a by-product, we characterize the optimal g-component cut under the condition that any two vertices have exactly two common neighbors if they have of any n-dimensional hypercube-like networks. [ABSTRACT FROM AUTHOR]

This study presents a new modular switched-capacitor DC-DC converter (MSCC) which is primarily designed with fault-tolerant capability to promote low-voltage applications such as fuel cells and photovoltaics. The converter can increase a low voltage level to a high voltage level by increasing the number of modules and/or the duty ratio. The proposed topology is modular and has high scalability for a high voltage gain. Another key advantage of the converter is its fault tolerance feature with a minimum change to the duty ratio. The proposed topology is first modeled analytically and then simulated in PSIM software with new control algorithms. The circuit architecture, operating principle, voltage/current stress and fault-tolerant operations are verified by using analytical and simulation methods based on a 200-V voltage supply. Moreover, experiments are also carried out on a low-voltage DC-DC prototype converter for validating the voltage ratio, efficiency and reliability. Test results have proved the effectiveness of the proposed topology under normal and fault conditions (open circuit faults of switches and capacitors). In addition to fuel cells, the developed converter can also be applied to photovoltaics and other low-voltage DC power systems which demand high efficiency, voltage output and high reliability. [ABSTRACT FROM AUTHOR]

In the power society, the fault location of the distribution network has always been the focus of scholars. When a fault occurs, it needs to be located quickly and accurately to avoid more significant losses. Due to the wide application of distributed generation in the distribution network, many traditional methods are no longer applicable. Thus, a fast and high fault tolerance method is urgently needed to solve the complex fault location problem of the distribution network. According to the logical and algebraic relationship of fault location, a linear integer programming model for fault section location of the distribution network is established. This paper adopts a new method for solving integer programming, called the fixed-point iterative method. This method has unique advantages in dealing with such large-scale problems and is easily realised through distributed computing, thereby saving time. Finally, through MATLAB experimental simulation, results show that the integer programming method can quickly locate the fault and has high fault tolerance. [ABSTRACT FROM AUTHOR]

Adders and Subtractors are an integral part of every digital information processing system. In general, it is always preferred to have a unified hardware that can perform both operations to reduce the area of circuits. The transistor technology is facing several difficulties to cope up with the targets set by Moore's law. Researchers have started to focus on finding alternatives. Quantum-dot Cellular Automata nanotechnology is suggested by the researchers for circuit design at nanoscale levels. A full adder-subtractor circuit using clock zone and multilayer crossover are proposed in this work. The results show that they have minimal cells and area. The fault tolerance capacity of the designs to missing cell defects is also analyzed. The full adder-subtractor coplanar design is 86.7% fault resistant and the multilayer design is 76.5% fault resistant. The coherence vector simulation engine is used to perform all the simulations in QCA designer. [ABSTRACT FROM AUTHOR]

Predicting impending failure of hard disk drives (HDDs) is crucial to avoid losing essential data and service downtime. However, most HDD failure prediction is being challenged by using labelled data itself to evaluate failure rate, while the fact that HDDs deteriorate gradually cannot be described and exploited suitably. Most works on the Self-Monitoring and Reporting Technology (SMART) system attributes utilize simple and traditional methods from machine learning and statistics to achieve HDD failure prediction. So, we propose a novel two-level prediction model Dab, hard Drive failure prediction based on deep Auto-coder and Big data learning, to exploit SMART data for better online HDD failure prediction, constructing detection sub-models of anomaly and health degree. With better accuracy, better performance, better prediction earnings, and proactive fault tolerance, Dab has reduced false alarm rate (FAR) and maintenance cost, and improved failure detection rate (FDR), reliability and robustness of large-scale storage systems. [ABSTRACT FROM AUTHOR]

The aim of this work is to introduce a new concept for a hydraulic semi-active yaw damper (SAYD) for the improvement of the stability of a high-speed rail vehicle. This concept represents a further elaboration of Secondary Yaw Control but envisages the use of semi-active hydraulic dampers instead of full-active electromechanical dampers, simplifying the design of the system and facilitating the design of a safe and fault tolerant device. Two control algorithms are proposed for the semi-active damper: maximum power point tracking and skyhook with Karnopp approximation. A multi-physics model of the SAYD is introduced and used in co-simulation with a multi-body model of a high-speed vehicle. Using these models, numerical simulations are performed to assess the behaviour of the semi-active damper in terms of improving the running stability of the rail vehicle at very high speed, showing that the use of the SAYD in combination with any of the two control strategies considered allows to improve substantially the stability of the vehicle. The results of experimental investigations performed in the project will be reported in a companion paper. [ABSTRACT FROM AUTHOR]

We generalise an approach to deriving diagnosability results of various interconnection networks in terms of the popular g-good-neighbour and g-extra fault-tolerant models, as well as mainstream diagnostic models such as the PMC and the MM* models. As demonstrative examples, we show how to follow this constructive, and effective, process to derive the g-extra diagnosabilities of the hypercube, the (n , k) -star, and the arrangement graph. These results agree with those achieved individually, without duplicating structure independent technical details. Some of them come with a larger applicable range than those already known, and the result for the arrangement graph in terms of the MM* model is new. [ABSTRACT FROM AUTHOR]

The fault tolerance of telecommunication networks is the ability to maintain service continuity in case of accident and attack. Designing disjoint paths to ensure fault tolerance of networks is regarded as one of the most important research problem. Especially in time-dependent networks which is used to the model that the weight of each link varies with time, answering shortest disjoint paths queries and plans in real time is considered to be one of major challenges in many industrial applications. Motivated by this observation, in the first in and first out (FIFO) time-varying network, we investigate the problem of finding two time-varying node-disjoint paths from the source to the destination with the departure time t ∈ [ 0 , T ] such that the total time-varying delay of the paths is minimised. Based on the time-varying interlacing path in different time-intervals, we develop an effective algorithm to obtain the optimal solutions in time O (n 2 α (T) 3). [ABSTRACT FROM AUTHOR]

This paper focuses on the output to state description-based convergent fault tolerant control (FTC) for a class of linear time invariant (LTI) systems. An output to state description theorem is proposed, by which, an adaptive output feedback FTC with a function equation constraint is designed for the LTI system in consideration. A controller reconfiguration algorithm is proposed to solve the constraint and construct an approximate controller that can compensate effectively the fault effect on systems. Furthermore, in certain conditions, the output feedback control gains can be determined by the state feedback control gains. A linear longitudinal dynamics of an aircraft and a linearised dynamic model of a vertical takeoff and landing (VTOL) aircraft in the vertical plane are applied to illustrate the effectiveness and merits of the proposed method. [ABSTRACT FROM AUTHOR]

Active suspension system can drastically improve dynamic behaviours of the railway vehicle but will also introduce safety-critical issues. The fault-tolerant analysis, therefore, is essential for the design and implementation of active suspension. However, this issue did not receive enough attention so far and only few papers can be found related to the fault tolerance of active steering for the railway vehicle. In this work, an approach based on Risk Priority Number is established to present quantitative assessment for fault tolerance of actuation system. Then this method is adopted to compare nine different active steering schemes resulting in a novel, comprehensive approach that enables a quantitative evaluation of different designs of the actuation system and of different principles to improve the fault tolerance. The impacts of typical failure modes are investigated through multi-body simulation and quantified by severity factor. Finally, the fault tolerance of different actuation schemes is evaluated by RPN values. [ABSTRACT FROM AUTHOR]

The growth of ubiquitous and pervasive computing systems with complex, heterogeneous, dynamic and mobile components, makes the utilization of structured overlay networks more desirable due to their inherent flexibility and extensibility to support modern day applications. However, the performance and dependability of structured overlay networks depend on their fault tolerance and self-managing capability to ensure an acceptable level of service in the face of mobility and anticipated churn. In this respect, this paper provides a systematic reference for the research work on the overlay geometries and churn handling mechanisms proposed in the literature to maintain the connectivity and reachability of overlay nodes in the presence of dynamic participants. Through an extensive literature search, we provide a taxonomic analysis of existing churn handling mechanisms, their qualitative comparison along with the detailed description of the factors behind the churn behaviour of the overlay participants in the existing applications. In addition, it highlights the key research issues to guide the future research in the field of churn handling. [ABSTRACT FROM AUTHOR]

The operation of electric vehicles is currently segmented in a scenario of smart grids as Vehicle to Grid (V2G), Vehicle to Home (V2H), Vehicle to Building (V2B), Vehicle to Load (V2L), among others. However, the migration of a type of vehicular applications toward its electrification that is of vital relevance is the medical/health assistance (human, animal, agronomist, environmental, etc.) or emergency services, called in this article vehicle-to-aid (V2A). Applications for V2A, for instance the electronic power converters that supply energy from the vehicle to the medical equipment, require offering very robust solutions against failures, including short circuits and component damages. In this paper, is proposed a new configuration of serial input and parallel output, not isolated, DC-DC converter with important properties of fault tolerance to component failures, robustness against variations in the parameters and tolerance to design errors. Analytical, numerical and experimental results, that validate the operation of the proposed configuration against failures and parameter variation, are presented. [ABSTRACT FROM AUTHOR]

In the present study, a new approach is suggested for the prediction of virtual machine (VM) failure based on the time series stochastic model. Motivated by various proactive fault tolerance techniques in the cloud, prediction of VM failure is highly anticipated. However, precise prediction of VM failure is extremely challenging and having a substantial impact on the proactive fault tolerance system. In proactive fault management techniques, it is essential to forecast the VM failure in the cloud and to characterize the system behavior. To predict the VM failure, we need to monitor the execution of VMs in the clouds dynamic environment and gather their health-related information. Therefore, in this paper, VM failure prediction is presented through a failure predictor module which is designed using time series based autoregressive integrated moving average. The suggested approach is tested on non-stationary failure trace of VM. It is observed that the proposed approach provides the failure prediction accurately. [ABSTRACT FROM AUTHOR]

High computation power is required to execute complex scientific workflows. Cloud computing resources are used viably to perform such complex workflows. Task clustering has demonstrated to be an efficient technique to decrease system overhead and to enhance the fine computational granularity tasks of a scientific workflow executed on distributed resources. However, earlier clustering methods ignore the effect of failures on the system, despite their significant impact on large-scale distributed resources, such as Clouds. In this paper, we present a new fault-tolerant task clustering method called FT-HCC that is designed by including the workflow execution time (makespan) and execution cost constraints, which are used to increase workflow performance. The proposed method is implemented and evaluated in a simulation-based approach, using a real-time workflow execution to analyze performance improvement. The results consolidate that the proposed strategies and techniques work efficiently in terms of fault tolerance and improve both workflow makespan and execution cost when compared to existing approaches. [ABSTRACT FROM AUTHOR]

Repoint is an alternative concept for the design of track switches developed at Loughborough University. The concept, based around a stub switch, offers several improvements over current designs. Through a novel locking arrangement, it allows parallel, multi-channel actuation and passive locking functions, providing a high degree of fault tolerance. The aim of the work presented in this paper is to evaluate the dynamic interaction forces due to the passage of rolling stock over the switch and, particularly, the area of the stub rail ends, in comparison to a conventional switch. Specific behaviour and load transfer conditions from one rail to the other at the joint are analysed, as well as long-term wear conditions of the rails. These evaluations are undertaken by means of multi-body dynamic simulations, leading to design refinement of the stub rail ends and the identification of further research and development requirements in their design. [ABSTRACT FROM AUTHOR]

An agile monitoring and diagnostic system plays a vital role in manufacturing, since it can considerably increase its robustness and efficiency. Applying agent technology to such systems is recognised as an appropriate approach, providing fault-tolerance and means for failure recovery in the case of sudden anomalies. In this article, we present an automation agent approach with agents comprising a software component with an integrated world model repository besides the related hardware. The world model is an explicit representation of the external surroundings and internals of the agent, and is used to detect anomalies in its own behaviour. We use an ontology to formalise the agent's knowledge. Applicability and functionality of our approach are presented in an example employing a real system. [ABSTRACT FROM AUTHOR]

Over the past several years, researchers have developed numerous control policies that assure deadlock-free operation for flexible manufacturing systems. Using this research base as a foundation, we have developed several supervisory policies that assure robust operation in the face of resource failure. Along with deadlock-free operation, these policies guarantee that failure of unreliable resources does not block production of part types not requiring failed resources. In our previous work, we developed two types of robust policies, those that 'absorb' all parts requiring failed resources into the buffer space of failure-dependent resources (resources that support only parts requiring failed resources), and those that 'distribute' parts requiring failed resources among the buffer space of shared resources (resources shared by parts requiring and parts not requiring failed resources). These two types of robust controllers assure different levels of robust system operation and impose very different operating dynamics on the system, thus affecting system performance in different ways. In this research, we use extensive simulation and experimentation on a highly complex and configurable system to develop guidelines for choosing the best robust supervisor based on manufacturing system characteristics and performance objectives. We validate these guidelines using seven randomly generated complex systems and find a better than 88% agreement. [ABSTRACT FROM AUTHOR]

Distributed microflow sensor arrays and networks are built from collections of spatially scattered, intelligent microflow sensor nodes. They can enhance the reliability and fault tolerance of the system. A new cluster network architecture and two original alternatives of fault-tolerant time-out communication protocol are described. Teamwork integration evaluator/micro-electromechanical system, a micro-electromechanical system sensor network simulation tool, was developed to evaluate the effectiveness of the network architectures and communication protocols. [ABSTRACT FROM AUTHOR]

Hardware fault tolerance is an important consideration in critical distributed real-time embedded systems and has been extensively researched. In these systems, critical real-time constraints must be satisfied even in the presence of hardware component failures. Our goal is to propose a solution to automatically produce a fault-tolerant distributed schedule of a given algorithm onto a given distributed architecture, according to real-time constraints. The distributed architectures we consider have bidirectional point-to-point communication links. Our solution is a list scheduling heuristics, based on disjoint paths to tolerate a fixed number of arbitrary processor and communication link failures. Because of the resource limitation in embedded systems, our heuristics implements a software solution based on the active replication technique, where each operation of the algorithm is replicated on different processors. With a detailed example, we show the techniques used to satisfy the real-time constraints and tolerate the failure of processor and communication links. Simulations show the efficiency of our method compared with other heuristics found in the literature. [ABSTRACT FROM AUTHOR]

In the present era, rapid transits are one of the most affordable means of public transport with various useful integrated application systems. The majority of the integrated applications are deployed in concern over safety and precautionary measures against the worst side-effects of unfortunate emergencies. For such cases, high-end reliable and autonomous systems provide possible positive solutions. Wireless Sensor Network is one of the suitable choices for rapid transit applications to gain positive results with inexpensive implementation cost. However, managing few network consequences like fault tolerance, energy balancing and routing critical informative packets are considered to be the challenging task due to their limited resource usage restriction. In this paper, a novel fuzzy logic-based fault tolerance and instant synchronized routing technique have been proposed specifically for the rapid transit system. On utilizing the fuzzy logic concepts, most of the computational complexities and uncertainties of the system is reduced. The central thematic of the proposed design is concerned over the synchronized routing and permanent faults which abruptly depicts the non-functional nature of the sensor nodes during normal operations. Moreover, our proposed simulation outcomes proved to be improvised evidence on obtaining maximum packet delivery ratio which tends to handle an emergency situation in the compartments of rapid transits. [ABSTRACT FROM AUTHOR]

The object of this article is to study the consequences of occurrence both fault in input and multiple time-varying delays simultaneously while designing observer to estimate the states of agents and also unknown nonlinear fault of system. Two delay dependent criteria are established to show the states of observer reach to states of MAS and also states of observer reach to consensus. From two obtained criteria, it can be deduced, by constructing a distributed controller-based observer design, MAS reach to consensus exponentially. Finally, the advantages of the obtained results are shown by solving an illustrative example. [ABSTRACT FROM AUTHOR]

In a heterogeneous distributed computing environment, developing a fault tolerance mechanism is a key research issue. Most of the existing fault tolerance approaches for distributed computing environment are post-active. These post-active approaches, predominantly involve the heartbeat strategy for fault detection and the checkpointing mechanism for fault recovery. In this proposed work, a proactive Health Aware Fault Tolerant (HAFT) scheduler using the Cox Proportional Hazard survival probability model is developed. The survival probability of the resource is estimated using resource failure data analytics and termed as health coefficient of the resource. For the job distribution classes jclass1, jclass2, and jclass3, the average improvement for makespan in HAFT algorithm over the compared algorithms are 44, 59.6, and 26.4%. In a heterogeneous environment, the job failure rate of the HAFT scheduler is ranging between 15 and 20% and it is stable for all the three jclasses. In a homogenous environment, the job failure rate of HAFT algorithm in comparison to IRP, REP and MJSP algorithm is considerably reduced by 58.6, 26.4, and 11.6%, respectively. For a failure probability higher than 0.4, the resource efficiency of HAFT algorithm on an average is 26% more than MJSP and 53% more than REP. [ABSTRACT FROM AUTHOR]

Multistage interconnection networks (MINs) are good choices to make the connection between processor nodes/memory modules for multiprocessor systems due to their cost effectiveness. However, these networks are basically non-fault-tolerant, which makes them an unreliable network. So far, various methods have been developed to improve the fault tolerance of the MINs. However, all of these methods are designed without considering the sensitive points of their systems. Nowadays, in modern approaches for effective improving fault tolerance, a basic requirement is to perform reliability importance analysis to identify crucial components in a system should be improved. Therefore, the aim of this paper is to analyse the reliability importance of switching elements in one of the most famous MINs called shuffle-exchange network (SEN) and its variants namely SEN+ (SEN with one additional stage) and SEN + 2 (SEN with two additional stages). This study has two important achievements: first, by replacement of sensitive elements, it reaches high-reliable networks; second, fault avoidance can be used as a substitute for fault tolerance methodology by using high-reliability switching elements and it is usually less expensive than fault tolerance. [ABSTRACT FROM AUTHOR]