DESIGNING FAULT TOLERANT ALGORITHMS FOR RECONFIGURABLE MESHES

2005 ◽  
Vol 16 (01) ◽  
pp. 71-88
Author(s):  
JOSÉ ALBERTO FERNÁNDEZ-ZEPEDA ◽  
ALEJANDRO ESTRELLA-BALDERRAMA ◽  
ANU G. BOURGEOIS
Keyword(s):  
Execution Time ◽  
Fault Tolerant ◽  
Fault Model ◽  
Scalable Algorithms ◽  
Reconfigurable Meshes ◽  
Removal Model

This paper proposes a procedure to design fault tolerant algorithms for the R-Mesh and some of its restrictive variations. This procedure first identifies a healthy sub-mesh from a faulty model using the bypass and removal fault model. Then it uses scalable algorithms to simulate the larger faulty model on the resulting healthy sub-mesh. The algorithms for the bypass model tolerates n faults in an n×n R-Mesh (LR-Mesh) and runs in O(T log n) (O(T)) time, where T is the execution time on the original mesh without faults. For the removal model, we design fault tolerant algorithms for some interesting variations of the R-Mesh, specifically, the NXR-Mesh and the NXLR-Mesh. We propose the first scaling simulations for these models and present a simulation of the R-Mesh on the NXR-Mesh. The results of this paper enable us to consider certain reconfigurable models in a more practical environment than previously allowed.

A Study on Fault Model and Fault-Tolerant Routing for Sensor Networks

2012 ◽  
Vol 182-183 ◽  
pp. 1265-1269
Author(s):  
Zu Ming Xu ◽  
Xiong Fu
Keyword(s):  
Sensor Networks ◽  
Routing Protocols ◽  
Energy Efficient ◽  
Fault Tolerant ◽  
Network Reliability ◽  
Fault Model ◽  
Cross Layer ◽  
Cross Layer Design ◽  
Fault Models ◽  
Energy Aware

Wireless sensor networks require energy-efficient and robust routingprotocols. Most routing protocols for sensor networks try to extendnetwork lifetime by minimizing the energy consumption, but have not taken the network reliability into account. In this paper, we analyze the fault models and propose an ENergy-aware FAult-tolerantRouting scheme, termed as ENFAR. Firstly a link-based uniform fault model is presented, and we adopt a cross-layer design to measurethe transmission delay so as to detect the failed nodes.

Research on Stator Winding Inter Turn Short-Circuit Faults of Aeronautical Fault-Tolerant Machine Based on Maxwell 2D

2011 ◽  
Vol 130-134 ◽  
pp. 119-123
Author(s):  
Ming Zhang ◽  
Yi Ming Zhang ◽  
Jiang Tao Tong
Keyword(s):  
Fault Tolerant ◽  
Short Circuit ◽  
Fault Model ◽  
Stator Winding ◽  
High Power Density ◽  
Induced Voltage ◽  
Magnetic Field Simulation ◽  
Voltage Frequency ◽  
Solid Foundation ◽  
Short Circuit Fault

Stator winding inter turn short-circuit fault is one of the most common internal faults of fault-tolerant machine, which can disconnect the fault phases and keep operating correctly in the event of a failure. Stator winding short-circuit fault model is established through analysis. Based on finite element method, the high-power density fault-tolerant machine internal magnetic field simulation and analysis is implemented using Maxwell2D and induced voltage frequency spectrum is analyzed by FFT method. The characteristics of stator winding short-circuit faults are summarized, which lay a solid foundation for fault-tolerant machine earlier faults prediction and winding switching.

scholarly journals Test

2021 ◽  
pp. 381-391
Author(s):  
Peter Marwedel
Keyword(s):  
Physical System ◽  
Fault Tolerant ◽  
Fault Injection ◽  
Fault Simulation ◽  
Fault Coverage ◽  
Fault Model ◽  
Pattern Generation ◽  
Signature Analysis ◽  
Fault Tolerant Systems ◽  
Random Patterns

AbstractUnfortunately, we cannot rely on designed and possibly already manufactured systems to operate as expected. These systems may have become defective during their use, or their function may have been compromised during the fabrication or their design. The purpose of testing is to verify whether or not an existing embedded/cyber-physical system can be operated as expected. In this chapter, we will present fundamental terms and techniques for testing. There will be a brief introduction to the aims of test pattern generation and their application. We will be introducing terms such as fault model, fault coverage, fault simulation, and fault injection. Also, we will be presenting techniques which improve testability, including the generation of pseudo-random patterns, and signature analysis. It would be beneficial to consider testability issues already during design. In case of fault-tolerant systems, resilience must be verified.

An active fault-tolerant control strategy of aircraft engines based on multi-model predictive control

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xian Du ◽  
Yan-Hua Ma
Keyword(s):  
High Pressure ◽  
Model Predictive Control ◽  
Predictive Control ◽  
Active Fault ◽  
Fault Tolerant ◽  
Control Sample ◽  
Fault Model ◽  
Aircraft Engines ◽  
Component Level ◽  
Predictive Controller

AbstractIn order to mitigate or even eliminate the adverse effects caused by typical components faults of aircraft engines, an active fault-tolerant strategy based on multi-model predictive control is proposed, which consists of a pre-established multi-model library, a judgement module, and corresponding predictive controllers with smooth transition switching logic. Multiple dynamic nonlinear or linear models are firstly established by means of system identification methods, based on the component-level nonlinear engine model or historical data in faults cases. The judgement module is utilized to online compare the engine measured outputs with that of all models in the pattern library and select the best matched dynamic model on the basis of outputs error quadratic performance index, thus determining the most appropriate predictive controller for the next control sample period. When a certain fault occurs, the fault model in the library could be identified and fault-model based predictive controller is activated. Finally, two kinds of pre-considered high-pressure compressor and high-pressure turbine component-level faults are taken as an example to design the active fault-tolerant controller. Simulation results show that the judgement module owns the ability to sense the fault and gives smooth switching signal to the suitable predictive controller, verifying the effectiveness of the proposed technique.

Improved Checkpoint Using the Effective Management of I/O in a Cloud Environment

2019 ◽  
pp. 219-233
Author(s):  
Bakhta Meroufel ◽  
Ghalem Belalem
Keyword(s):  
Fault Tolerance ◽  
Execution Time ◽  
Large Scale ◽  
Fault Tolerant ◽  
Experimental Results ◽  
Cloud Environment ◽  
Large Scale Systems ◽  
Major Disadvantage ◽  
Reliability And Robustness ◽  
Effective Use

One of the most important points for more effective use in the environment of cloud is undoubtedly the study of reliability and robustness of services related to this environment. In this case, fault tolerance is necessary to ensure that reliability and reduce the SLA violation. Checkpointing is a popular fault tolerance technique in large-scale systems. However, its major disadvantage is the overhead caused by the storage time of checkpointing files, which increases the execution time and minimizes the possibility to meet the desired deadlines. In this chapter, the authors propose a checkpointing strategy with lightweight storage. The storage is provided by creating a virtual topology VRbIO and the use of an intelligent and fault tolerant I/O technique CSDS (collective and selective data sieving). The proposal is executed by active and reactive agents and it solves many problems of checkpointing with standard I/O. To evaluate the approach, the authors compare it with a checkpointing with ROMIO as I/O strategy. Experimental results show the effectiveness and reliability of the proposed approach.

scholarly journals Generalized Paxos Made Byzantine (and Less Complex)

Algorithms ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 141
Author(s):  
Miguel Pires ◽  
Srivatsan Ravi ◽  
Rodrigo Rodrigues
Keyword(s):  
Fault Tolerant ◽  
Fault Model ◽  
Correctness Proof ◽  
Safety Condition ◽  
Byzantine Fault ◽  
Simple Implementation

One of the most recent members of the Paxos family of protocols is Generalized Paxos. This variant of Paxos has the characteristic that it departs from the original specification of consensus, allowing for a weaker safety condition where different processes can have a different views on a sequence being agreed upon. However, much like the original Paxos counterpart, Generalized Paxos does not have a simple implementation. Furthermore, with the recent practical adoption of Byzantine fault tolerant protocols in the context of blockchain protocols, it is timely and important to understand how Generalized Paxos can be implemented in the Byzantine model. In this paper, we make two main contributions. First, we attempt to provide a simpler description of Generalized Paxos, based on a simpler specification and the pseudocode for a solution that can be readily implemented. Second, we extend the protocol to the Byzantine fault model, and provide the respective correctness proof.

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