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fault tolerant Algorithm Based on Dynamic and Active Load Balancing for Redundant Services

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Journal of Computer Science & Technology 2004年第6期19卷 769-775页

作者： Jun-FengTian Jun-WeiZhang Feng-XianWang DepartmentofComputerScienceandTechnology UniversityofScienceandTechnologyofChinaHefei230027P.R.China MathematicsandComputerCollege HebeiUniversityBaoding071002P.R.China

A new Some-Read-Any-Write (SRAW) fault tolerant algorithm for redudant services is presented that allows a system to adjust failures dynamically in order to keep the availability and improve the performance. SRAW is based upon dynamic and active load balancing. By introducing dynamic and active load balancing scheme into redundant services, not only the processing speed of requests can be greatly improved, but also the load balancing can be simply and efficiently achieved. Integrated with consistency protocol in this paper, SRAW can also be applied to state services. The performance of SRAW algorithm is also analyzed, and comparisons with other fault tolerant algorithms, expecially with RAWA, indicate that SRAW efficiently improves the performance of redundant services with guaranteeing system availability. Keywords redundant service - fault tolerant - active - load balancing - quorum Supported by the Hebei Province Natural Science Foundation of China under Grant No.600091.Jun-Feng Tian received the B.S. degree in electrical engineering and the M.S. degree in computer application both from Hebei University, in 1986 and in 1995 respectively. Currently, he is a Ph.D. candidate in University of Science and Technology of China. He is a professor at Hebei University. His current research interests include network technology, system architecture and distributed computing.Jun-Wei Zhang was born in 1977 and received the B.S. and M.S. degrees in computer application from Hebei University, P.R. China, in 2000 and 2003, respectively. His current research interests include software fault tolerance and load balancing.Feng-Xian Wang received the B.S. degree in electrical engineering from Hebei University, P.R. China, in 1978. He is a professor in Hebei University. His current research interests include network security and distributed computing.

关键词： redundant service fault tolerant active load balancing quorum

fault tolerant control with torque limitation based on fault mode for ten-phase permanent magnet synchronous motor

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Chinese Journal of Aeronautics 2015年第5期28卷 1464-1475页

作者： Guo Hong Xu Jinquan School of Automation Science and Electrical Engineering Beihang University

This paper proposes a novel fault tolerant control with torque limitation based on the fault mode for the ten-phase permanent magnet synchronous motor （PMSM） under various open-circuit and short-circuit fault conditions, which includes the optimal torque control and the torque limitation control based on the fault mode. The optimal torque control is adopted to guarantee the ripple-free electromagnetic torque operation for the ten-phase motor system under the post-fault condition. Furthermore, we systematically analyze the load capacity of the ten-phase motor system under different fault modes. And a torque limitation control approach based on the fault mode is proposed, which was not available earlier. This approach is able to ensure the safety operation of the faulted motor system in long operating time without causing the overheat fault. The simulation result confirms that the proposed fault tolerant control for the ten-phase motor system is able to guarantee the ripple-free electromagnetic torque and the safety operation in long operating time under the normal and fault conditions.

关键词： fault mode fault tolerant Optimal torque control Permanent magnet motorTorque limitation

A novel fault tolerant permanent magnet synchronous motor with improved optimal torque control for aerospace application

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Chinese Journal of Aeronautics 2015年第2期28卷 535-544页

作者： Guo Hong Xu Jinquan Kuang Xiaolin School of Automation Science and Electrical Engineering Beihang University

Improving fault tolerant performance of permanent magnet synchronous motor has always been the central issue of the electrically supplied actuator for aerospace application. In this paper, a novel fault tolerant permanent magnet synchronous motor is proposed, which is character- ized by two stators and two rotors on the same shaft with a circumferential displacement of mechanical angle of 4.5°. It helps to reduce the cogging torque. Each segment of the stator and the rotor can be considered as an 8-pole/10-slot five-phase permanent magnet synchronous motor with concentrated, single-layer and alternate teeth wound winding, which enhance the fault isola- tion capacity of the motor. Furthermore, the motor has high phase inductance to restrain the short-circuit current. In addition, an improved optimal torque control strategy is proposed to make the motor work well under the open-circuit fault and short-circuit fault conditions. Simulation and experiment results show that the proposed fault tolerant motor system has excellent fault tolerant capacity, which is able to operate continuously under the third open-circuit fault and second short- circuit fault condition without system performance degradation, which was not available earlier.

关键词： Actuator fault isolation fault tolerant Optimal torque control Permanent magnet moto

A fault tolerant model for multi-sensor measurement

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Chinese Journal of Aeronautics 2015年第3期28卷 874-882页

作者： Li Liang Shi Wei Information and Ecommerce Institute University of Electronic Science & Technology of China China Gas Turbine Establishment

Abstract Multisensor systems are very powerful in the complex environments. The cointegration theory and the vector error correction model, the statistic methods which widely applied in economic analysis, are utilized to create a fitting model for homogeneous sensors measurements. An algorithm is applied to implement the model for error correction, in which the signal of any sensor can be esti mated from those of others. The model divides a signal series into two parts, the training part and the estimated part. By comparing the estimated part with the actual one, the proposed method can iden tify a sensor with possible faults and repair its signal. With a small amount of training data, the right parameters for the model in real time could be found by the algorithm. When applied in data analysis for aero engine testing, the model works well. Therefore, it is not only an effective method to detect any sensor failure or abnormality, but also a useful approach to correct possible errors.

关键词： Cointegration fault tolerant Measurement Multi-sensor Turbine engine

Algorithms for k-fault tolerant power assignments in wireless sensor networks

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Science China(Information Sciences) 2010年第12期53卷 2527-2537页

作者： LIU Li 1,2,LI Lian 1,3 & HU Bin 1,4 1 School of Information Science and Engineering,Lanzhou University,Lanzhou 730000,China 2 LRI,Univ Paris-sud and CNRS,Orsay F-91405,France 3 School of Computer and Information,Hefei University of Technology,Hefei 230009,China 4 Department of Computing,Birmingham City University,Galton Building,Perry Barr,Birmingham B42 2SU,UK School of Information Science and Engineering Lanzhou University LRI Univ Paris-sud and CNRS School of Computer and Information Hefei University of Technology Department of Computing Birmingham City University

This paper addresses fault-tolerant many-to-many routing power assignments in heterogeneous wire-less sensor *** introduce the k-fault tolerant power assignments problem with the objective of assigning each sensor node transmission power such that(1) any pairwise sensor node is k-vertex connected and(2) the to-tal power consumption is *** propose three solutions for this problem:two centralized algorithms,a greedy algorithm and an O(√n/ε)-approximation algorithm,and an h-hop distributed and localized *** theorems and proofs are presented to prove the correctness of our ***,simulation and experiment results are presented to verify the efficiency of our approaches.

关键词： heterogeneous wireless sensor network fault tolerant power consumption algorithm

A DYNAMIC fault tolerant ALGORITHM FOR IMPROVISING PERFORMANCE OF MULTIMEDIA SERVICES

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Journal of Pharmaceutical Analysis 2005年第2期17卷 11-15页

作者：张明龙冯博琴刘芳 School of Electronics and Information Engineering Xi'an Jiaotong University Xi'an 710049 China

Multimedia Services has drawn much attention from both industrial and academic researchers due to the emerging consumer market, how to provide High-Availability service is one of most important issues to take into account. In this paper, a dynamic fault tolerant algorithm is presented for highly available distributed multimedia service, then by introducing SLB(server load balancing) into fault tolerance and switching servers in different ways according to their functions, the proposed schema can preserve reliability and real-time of the system .The analysis and experiments indicate that resuming server's faulty by this method is smooth and transparent to the client The proposed algorithm is effectively improving the reliability of the multimedia service.

关键词： fault tolerant SLB server switching

fault tolerant Routing Protocol in Wireless Sensor Networks

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Fault Tolerant Routing Protocol in Wireless Sensor Networks

Relay Node Placement with Base Stations in Wireless Sensor Networks fault-tolerant

第五届中国测试学术会议

作者： Song Yan-yan Zuo De-cheng Yang Xiao-zong Cui Gang Liu Hong-wei School of Computer Science and Technology,Harbin Institute of Technology,Hei Long Jiang,Harbin 150001

＜正＞In order to prolong the lifetime of wireless sensor networks,we did some exploring researches on the topology control of the wireless sensor *** paper proposes a fault tolerant Routing Protocol,called FTRP,which can save the energy of sensor networks, thus expend the *** simulation of the protocol is done in the OPNET Modeler ***,the energy performance comparison between ours and Temporary Ordered Routing Algorithm （TORA）,Dynamic Source Routing Protocol （DSR） is also provided in similar simulation *** results show that FTRP exhaust much less energy than TORA and DSR in per unit time,thus FTRP has longer lifetime.

关键词： sensor network robust routing protocols fault tolerant network lifetime

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Chinese Journal of Electronics 2014年第4期23卷 794-800页

作者： GAO Zhipeng CHEN Kan QIU Xuesong State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications

It has been proposed to deploy relay nodes for the sake of prolonging Wireless sensor networks(WSN)lifetime, such that sensors transmit the sensed data to them which in turn delivers the data to base stations. For survivability requirements, relay placements which considers fault tolerant ability have been noticed and studied. While related works are limited or most existing works don't take factors such as fault tolerance, or base stations into account comprehensively in two tired WSN. We focus on fault tolerant relay node placement in two-tiered heterogeneous WSN with base stations. As far as we know,fault tolerance contains two fundamental aspects, for one is multi-coverage and the second is multi-path. It is a NPhard problem and figure out an approximation, whose approximation ratio is enhanced to be(18 +). While a sub-problem approximation is also described as supplementary. Experimental results verify that the number of relay nodes deployed by our algorithm is somewhat superior to existed relay node placement solutions.

关键词： Relay node placement Wireless sensor networks fault tolerant Connectivity Approximations ratio

Iaso： an autonomous fault-tolerant management system for supercomputers

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Frontiers of Computer Science 2014年第3期8卷 378-390页

作者： Kai LU Xiaoping WANG Gen LI Ruibo WANG Wanqing CHI Yongpeng LIU Hongwei TANG Hua FENG Yinghui GAO Science and Technology on Parallel and Distributed Processing Laboratory National University of Defense Technology Changsha 410073 China College of Computer National University of Defense Technology Changsha 410073 China ATR Laboratory National University of Defense Technology Changsha 410073 China

With the increase of system scale, the inherent reliability of supercomputers becomes lower and lower. The cost of fault handling and task recovery increases so rapidly that the reliability issue will soon harm the usability of supercomputers. This issue is referred to as the ＂reliability wall＂, which is regarded as a critical problem for current and future supercomputers. To address this problem, we propose an autonomous fault-tolerant system, named Iaso, in MilkyWay- 2 system. Iaso introduces the concept of autonomous management in supercomputers. By autonomous management, the computer itself, rather than manpower, takes charge of the fault management work. Iaso automatically manage the whole lifecycle of faults, including fault detection, fault diagnosis, fault isolation, and task recovery. Iaso endows the autonomous features with MilkyWay-2 system, such as self-awareness, self-diagnosis, self-healing, and self-protection. With the help of Iaso, the cost of fault handling in supercomputers reduces from several hours to a few seconds. Iaso greatly improves the usability and reliability of MilkyWay-2 system.

关键词： supercomputer autonomous management fault tolerant fault management MilkyWay-2 system