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OFC/NFOEC 2007 - Optical Fiber Communication and the National Fiber Optic Engineers Conference 2007

作者： Liu, Fangfei Su, Yikai Voss, Paul L. State Key Lab. of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai Jiao Tong University 800 DongChuan Rd Shanghai 200240 China School of Electrical and Computer Engineering Georgia Institute of Technology 777 Atlantic Drive Atlanta GA 30332-0250 United States Georgia Tech Lorraine GT-CNRS UMI 2958 2-3 rue Marconi Metz F-57070 France

We study optimal operating conditions for 160-Gb/s signals traversing a slow-light delay line based on parametric amplification. Six phase modulated formats are investigated, including CSRZ, PAP-CSRZ, GAP-CSRZ, RZ duo... 详细信息

ISBN: (纸本)1557528314

关键词： Fiber amplifiers

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XRD and HRTEM Analyses of the Ball Milled Nanocrystalline FeCo Alloy

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Journal of Wuhan University of technology(Materials Science) 2006年第1期21卷 68-71页

作者：王琦官建国 State Key Lab of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070ChinaSchool of Materials Science and EngineeringJinan UniversityJinan 250022China State Key Lab of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070China

The nanostractures of the ball milled FeCo particles were characterized as functions of the ball milling time （ t ） using quantitative X- ray diffraction （ XRD ）, high resolution transmission electron microscopy （HRTEM） analysis techniques. The results show that the nanocrystalliue bcc FeCo particles are available using carbonyl iron and cobalt powders as the start materials during the high-energy ball milling. At the early stage of ball milling, Co powders are easily mashed into nanocrystalllites, by which the surface of the larger Fe particles of about 80- 150 nm is coated. With t increasing, the refinement of grain size and the incorporation of defects including dislocations, disclinations and grain boundaries happen, and then FeCo alloy with a certain layered structure is formed, finally the layered stractare disappears with the formation of isotropic grains having a steadystate grain size in the nanometer regime after a certain period of t.

关键词： high energy ball milling carbonyl iron cobalt alloy nanocrystalline materials

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On the quality of service of failure detectors based on control theory

On the quality of service of failure detectors based on cont...

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20th International Conference on advanced Information Networking and Applications

作者： Xiong, Naixue Yang, Yan Chen, Jianxun He, Yanxiang School of Information Science Japan Advanced Institute of Science and Technology Japan Computer Science and Technology School Wuhan University of Science and Technology China State Key Lab of Software Engineering Computer School Wuhan University China

ISBN: (纸本)0769524664

The detection of failures is a fundamental issue for fault tolerance in distributed systems. Recently, many people have come to realize that failure detection ought to be provided as some form of generic service, similar to IP address lookup. However, this has not been successful so far;one of the reasons being the fact that classical failure detectors were not designed to satisfy several application requirements simultaneously. More specifically, traditional implementations of failure detectors are often tuned for running over local networks and fail to address some important problems found in wide-area distributed systems with a large number of monitored components. In this paper, we study the quality of service (QoS) of failure detectors. We first present a novel failure detector scheme combined with control theory that can help in solving or optimizing some problems. Furthermore, this paper discusses the design and analysis of implementing a scalable failure detection service for such large wide-area distributed systems considering dynamically adjusting the heartbeat streams, so that it satisfies the bottleneck router requirements. We further show how the online failure detector control algorithm can be used to design a controller, analyze the theoretical aspects of the proposed algorithm and verify its agreement. Simulation results show the efficiency of our scheme in terms of high utilization of the bottleneck link fast response and good stability of the bottleneck router buffer occupancy as well as of the controlled sending rates. In conclusion, the new failure detector algorithm provides a better QoS than an algorithm that is proposed by Stelling et al [1, 2].

关键词： Telecommunication services

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Optimal operating conditions and modulation format for 160Gb/s signals in a fiber parametric amplifier used as a slow-light delay line element

Optimal operating conditions and modulation format for 160Gb...

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Optical Fiber Communication - OFC 2007 Collocated National Fiber Optic Engineers Conference (OFC 2007), vol.2

作者： Fangfei Liu Yikai Su Paul L. Voss State Key Lab of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai Jiao Tong University 800 DongChuan Rd Shanghai 200240 China School of Electrical and Computer Engineering Georgia Institute of Technology 777Atlantic Drive Atlanta GA USA 30332-0250 Georgia Tech Lorraine GT-CNRS UMI2958 2-3 rue Marconi Metz France F-57070

ISBN: (纸本)1557528306

关键词： Differential phase shift keying Fiber optic amplifiers Modulation Modulation techniques Packet switched networks Phase shift Nonlinear optics (190.0190) Parametric oscillators and amplifiers (190.4970)

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On designing QoS for congestion control service using neural network predictive techniques

On designing QoS for congestion control service using neural...

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IEEE International Conference on Granular Computing

作者： Xiong, N. Yang, Y. He, Jing He, Yanxiang IEEE Japan School of Information Science Japan Advanced Institute of Science and Technology Japan Department of Computer Science Utah State University Logan UT 84322-4205 United States State Key Lab. of Software Engineering Computer School Wuhan University China

ISBN: (纸本)142440133X

With the ever-increasing data transmission applications recently, considerable efforts have been focused on the design of congestion control scheme for data transmission service to guarantee the quality of service (QoS). The main difficulty in designing an efficient congestion controller for data transmission service stems from the heterogeneous receivers, especially those with large propagation delays in data transfer, which also mean the feedbacks arriving at the source are somewhat outdated and can be harmful to the control actions. This usually leads to a mismatch between the network resources and the amount of admitted traffic. To attack this problem, the present paper describes a novel congestion control scheme that is based on a Back Propagation (BP) neural network technique. We consider a general computer communication model with multiple sources and one destination node. This network-assisted property is different from the existed control scheme in that the data source can predict the dynamic of buffer occupancy of the bottleneck node for which the back control packets experience very long propagation delay and probably cause irresponsiveness of a. data flow. This active scheme makes the control more responsive to the network status. Thus the rate adaptation can be in a timely manner for the sender to react to network congestion quickly. We analyze the theoretical aspects of the proposed algorithm, show how the control mechanism can be used to design a controller to support the data transmission based on feedback of explicit rates' (ER's), and verify this agreement by the simulations. Simulation results show the efficiency of our scheme in terms of quickly response and excellent predictive accuracy.

关键词： neural network applications neural networks traffic control (communication) interconnection networks transportation networks

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On control gain selection in PI-RED

On control gain selection in PI-RED

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2006 IEEE International Conference on Networking, Sensing and Control, ICNSC'06

作者： Naixue, Xiong Xavier, Defago Yan, Yang Yanxiang, He Jing, He Asahidai Nomi Ishikawa Japan State Key Lab. of Software Engineering Computer School Wuhan University China School of Information Science Japan Advanced Institute of Science and Technology Japan School of Computer Science and Technology Wuhan University of Science and Technology Hu Bei province China State Key Lab. of Software Engineering Computer School Wuhan University Hu Bei province China Department of Computer Science Utah State University Logan UT 84322-4205 United States

ISBN: (纸本)1424400651

Active Queue Management (AQM) is an effective method used in Internet routers to enhance congestion control, and to achieve a trade off between link utilization and delay. The de facto standard, the Random Early Detection (RED) AQM scheme, and most of its variants use queue length as a congestion indicator to trigger packet dropping. Random early detection (RED) is a widely studied active queue management (AQM) scheme implemented in routers for Internet congestion control. Although certain stability conditions for various RED controllers are discussed, no efficient method for dynamically adapting control gains or result on control gain optimization has been proposed so far. Therefore based on control theory, this paper proposes Proportional and Integral RED (PI-RED) algorithm, that not only considers the average queue length at the current time slot, but also takes into consideration the past average queue lengths within a round trip time. We provides guidelines for the selection of the feedback gains (the proportional parameter and the integral parameter) for TCP/RED system to stabilize the dynamics, make the congested queue converge at a certain target and hence to improve network performance. Simulations demonstrate that indeed satisfactory performance can be achieved if the control gains are selected based on the guidelines. Based on the stability condition and control gains selection method, extensive simulations with ns2 demonstrate that indeed satisfactory performance can be achieved in terms of robustness, drop probability and stability if the control gains are selected based on the guidelines. © 2006 IEEE.

关键词： Control system analysis

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Research on preparing Fe3O4 nanoparticles by polyol process and magnetic properties

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Gongneng Cailiao/Journal of Functional Materials 2006年第12期37卷 2001-2002+2006页

作者： Liu, Biao Guan, Jian-Guo Zhang, Qing-Jie School of Materials Science and Engineering Jinan University Ji'nan 250022 China State Key Lab. of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

Fe3O4 nanoparticles were prepared unexpectedly by polyol process using FeCl2&middot4H2O as precursor, 1,2-propylene glycol as reducer. The as-prepared sample was characterized by XRD analysis. The morphology obser... 详细信息

Fe3O4 nanoparticles were prepared unexpectedly by polyol process using FeCl2·4H2O as precursor, 1,2-propylene glycol as reducer. The as-prepared sample was characterized by XRD analysis. The morphology observed by TEM showed that the shape of Fe3O4 nanoparticles was, the size of them was 50-70 nm. The reaction mechanism research showed that the disproportionation of Fe2+ ions had occurred and the Fe2+ ions had been oxidized to produce Fe3O4 nanoparticles. The hysteresis loop measured by VSM showed that the saturation magnetization was 74.30 A·m2/kg, the coercivity was 102.68 A/m which was shown that the Fe3O4 nanoparticles were superparamagnetic.

关键词： Nanostructured materials

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Design and analysis of a self-tuning proportional and integral controller for active queue management routers to support TCP flows

Design and analysis of a self-tuning proportional and integr...

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INFOCOM 2006: 25th IEEE International Conference on Computer Communications

作者： Xiong, Naixue Défago, Xavier Jia, Xiaohua Yan, G. He, Yanxiang School of Information Science Japan Advanced Institute of Science and Technology State Key Lab. of Software Engineering Computer School Wuhan University School of Information Science Japan Advanced Institute of Science and Technology 1-1 Asahidai Nomi Ishikawa 923-1292 Japan Kowloon Hong Kong IEEE IEEE Communication Society Department of Computer Science Wuhan University City University of Hong Kong Kowloon Hong Kong School of Computer Science and Technology Wuhan University of Science and Technology China SMIEEE

ISBN: (纸本)1424402212

Active Queue Management (AQM) is an effective method used in Internet routers for congestion control, and to achieve a tradeoff between link utilization and delay. The de facto standard, the Random Early Detection (RED) AQM scheme, and most of its variants use average queue length as a congestion indicator to trigger packet dropping. This paper proposes a novel AQM algorithm, called Self-tuning Proportional and Integral RED (SPI-RED), as an extension of RED. SPI-RED is based on a Self-tuning Proportional and Integral controller, which not only considers the average queue length at the current time point, but also takes into consideration the past average queue lengths during a round-trip time. Furthermore, we give theoretical analysis of the system stability and give guidelines for the selection of feedback gains for the TCP/RED system to stabilize the average queue length at a desirable level. Extensive simulations have been conducted with ns2. The simulation results have demonstrated that the proposed SPI-RED algorithm outperforms the existing AQM schemes in terms of drop probability and stability.

关键词： Queueing networks

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Fabrication of long period fiber gratings by carving periodic grooves on the fiber using a focused CO2 laser beam

Fabrication of long period fiber gratings by carving periodi...

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Optical Fiber Sensors, OFS 2006

作者： Wang, Yi-Ping Jin, Wei Wang, D.N. Rao, Yun-Jiang Department of Electrical Engineering The Hong Kong Polytechnic University Kowloon Hong Kong State Key Lab of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong University Shanghai 200240 China School of Communication and Information Eng University of Electronic Science and Technology of China Chengdu 610054 China

Fabrication of long period fiber gratings by use of a focused CO2 laser beam to carve periodic grooves on the fibre is demonstrated. A large transmission attenuation of -47.39dB at the resonant wavelength is experimen... 详细信息

ISBN: (纸本)1557528179

关键词： Laser beams

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On the quality of service of failure detectors based on control theory

On the quality of service of failure detectors based on cont...

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International Conference on advanced Information Networking and Applications (AINA)

作者： N. Xiong Yan Yang Jianxun Chen Yanxiang He The State Key Lab of Software Engineering Computer School of Wuhan University China Japan Advanced Institute of Science and Technology School of Information Science Japan Computer Science and Technology School Wuhan University of Science and Technology China

The detection of failures is a fundamental issue for fault tolerance in distributed systems. Recently, many people have come to realize that failure detection ought to be provided as some form of generic service, similar to IP address lookup. However, this has not been successful so far; one of the reasons being the fact that classical failure detectors were not designed to satisfy several application requirements simultaneously. More specifically, traditional implementations of failure detectors are often tuned for running over local networks and fail to address some important problems found in wide-area distributed systems with a large number of monitored components. In this paper, we study the quality of service (QoS) of failure detectors. We first present a novel failure detector scheme combined with control theory that can help in solving or optimizing some problems. Furthermore, this paper discusses the design and analysis of implementing a scalable failure detection service for such large wide-area distributed systems considering dynamically adjusting the heartbeat streams, so that it satisfies the bottleneck router requirements. We further show how the online failure detector control algorithm can be used to design a controller, analyze the theoretical aspects of the proposed algorithm and verify its agreement. Simulation results show the efficiency of our scheme in terms of high utilization of the bottleneck link, fast response and good stability of the bottleneck router buffer occupancy as well as of the controlled sending rates. In conclusion, the new failure detector algorithm provides a better QoS.

关键词： Quality of service Detectors Control theory Failure analysis Algorithm design and analysis Fault detection Fault tolerant systems Condition monitoring Heart beat Stability

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