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QUANTIZED H∞ CONTROL FOR NETWORKED SYSTEMS WITH COMMUNICATION CONSTRAINTS

ASIAN JOURNAL OF CONTROL 2013年第5期15卷 1468-1476页

作者： Yan, Huaicheng Shi, Hongbo zhang, Hao Yang, fuwen E China Univ Sci & Technol Minist Educ Key Lab Adv Control & Optimizat Chem Proc Shanghai 200237 Peoples R China E China Univ Sci & Technol Sch Informat Sci & Engn Shanghai 200237 Peoples R China Tongji Univ Dept Control Sci & Engn Shanghai 200092 Peoples R China City Univ Hong Kong Dept Mech & Biomed Engn Kowloon Hong Kong Peoples R China

The problem of quantized H control for networked control systems (NCSs) subject to time-varying delay and multiple packet dropouts is investigated in this paper. Both the control input and the measurement output signals are quantized before being transmitted and the quantized errors are described as sector bound uncertainties. The measurement channel and the control channel packet dropouts are considered simultaneously, and the stochastic variables satisfying Bernoulli random binary distribution are utilized to model the random multiple packet dropouts. Sufficient conditions for the existence of an observer-based controller are established to ensure the exponential mean-square stablility of the closed-loop system and achieve the optimal H disturbance attenuation level. By using a globally convergent algorithm involving convex optimization, the nonconvex feasibility can be solved successfully. Finally, a numerical example is given to illustrate the effectiveness and applicability of the proposed method.

关键词： H control networked control system quantization time-varying delay multiple packet dropouts

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螺丝连接钢板可逆加固木梁的试验研究

螺丝连接钢板可逆加固木梁的试验研究

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2013既有建筑绿色化改造关键技术研究与示范项目交流会

作者： XU Qingfeng 许清风 Jian-Fei CHEN 陈建飞 zhang fuwen 张富文 LI Xiangmin 李向民 Shanghai Key Laboratory of New Technology Research on Engineering Structure Shanghai 200032 China 上海市工程结构新技术重点实验室上海 200032 上海市建筑科学研究院(集团)有限公司上海 200032 The University of Edinburgh Edinburgh EH9 3JL UK 爱丁堡大学英国爱丁堡 EH9 3JL

优秀历史木结构建筑的维修加固方法要求具有可逆性,以保证其永续保护和适应性利用。本文共进行了11根螺丝连接钢板可逆加固木梁的对比试验研究,其中3根为未加固对比试件,8根为螺丝连接钢板加固木梁试件,试验参数包括螺丝直径、螺丝间距... 详细信息

优秀历史木结构建筑的维修加固方法要求具有可逆性,以保证其永续保护和适应性利用。本文共进行了11根螺丝连接钢板可逆加固木梁的对比试验研究,其中3根为未加固对比试件,8根为螺丝连接钢板加固木梁试件,试验参数包括螺丝直径、螺丝间距和钢板重复利用次数等。研究结果表明,螺丝连接钢板加固木梁的极限承载力显著提高,提高幅度为16％～79％,平均提高50％;初始弯曲刚度明显提高,提高幅度为21％～38％,平均提高30％;木梁跨中截面变形基本符合平截面假定。在相同荷载作用下,加固试件受拉边缘拉应变和受压边缘压应变均明显小于对比试件,加固试件跨中钢板应变明显滞后于木梁底面应变。理论计算和有限元分析结果均表明,螺丝连接钢板加固木梁受弯承载力计算值与试验值较为吻合,满足工程精度要求。螺丝连接钢板加固木梁是一种可逆的、可循环的、施工方便的、有效的加固方法,可用于优秀历史木结构特别是文物建筑的永续保护。

关键词：建筑工程木梁加固结构荷载螺丝连接钢板可逆加固技术

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Distributed average filtering for sensor networks with sensor saturation

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IET CONTROL THEORY AND APPLICATIONS 2013年第6期7卷 887-893页

作者： zhang, Hao Yan, Huaicheng Yang, fuwen Chen, Qijun City Univ Hong Kong Dept Mech & Biomed Engn Kowloon Hong Kong Peoples R China Tongji Univ Dept Control Sci & Engn Shanghai 200092 Peoples R China Minist Educ Key Lab Adv Control & Optimisat Chem Proc Shanghai 200237 Peoples R China E China Univ Sci & Technol Sch Informat Sci & Engn Shanghai 200237 Peoples R China

This study addresses the distributed average set-membership filtering of spatially varying processes using sensor networks. The system under consideration contains sensor saturation in the presence of unknown-but-bounded process and measurement noise in the sensor network. The so-called distributed average set-membership filtering is defined to quantify bounded consensus regarding the estimation error. A sufficient condition for distributed average set-membership filtering parameter design is established in terms of a set of time-varying linear matrix inequalities. A recursive algorithm is developed for computing the estimator, controller gains and the ellipsoid that guarantees to contain the true state. Simulation results are provided to demonstrate the effectiveness of the proposed method.

关键词： Distribute Sensor networks Sensors average filter Noise measurement Filtration

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Influence of Ar/H₂ ratio on the characteristics of boron-doped nc-Si:H films prepared by electron cyclotron resonance plasma-enhanced chemical vapor deposition

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SURFACE & COATINGS TECHNOLOGY 2013年第sup1期228卷 S412-S415页

作者： zhang, Xueyu Wu, Aimin Shi, Shaofei Qin, fuwen Dalian Univ Technol Key Lab Mat Modificat Minist Educ Dalian 116024 Peoples R China Dalian Univ Technol Sch Mat Sci & Engn Dalian 116024 Peoples R China Dalian Univ Technol Key Lab Solar Photovolta Syst Dalian 116024 Peoples R China Changchun Univ Technol Sch Mat Sci & Engn Changchun 130012 Peoples R China

Boron-doped hydrogenated nanocrystalline silicon (nc-Si(B):H) films were prepared by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD). The effect of Ar/H-2 ratio on the characteristic of as-grown nc-Si(B):H films was investigated systematically with Raman scattering, XRD, XPS as well as Hall effect measurements. The experimental results indicate that the increase of Ar/H-2 ratio can enhance the concentration of B in the as-grown films. On the other hand, with the Ar/H-2 ratio increasing, the crystallinity of the films deteriorated sharply, and the electrical properties of the as-grown films decreased. Langmuir Probe was used to investigate the electron temperature (T-e) of microwave activated B2H6/Ar/H-2 plasmas. Finally, the microscopic mechanism of the enhancement in doping efficiency was elucidated in terms of the plasma reaction equations of B2H6 and Langmuir probe testing result. (C) 2012 Elsevier B.V. All rights reserved.

关键词： Ar/H-2 P-type nc-Si:H ECR-PECVD Langmuir

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食品接触塑料材料中有害重金属迁移量测定方法综述

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化学分析计量 2015年第1期24卷 101-105页

作者：赵付文孙卓军高国庆张前前高君高建国中国海洋大学化学化工学院山东青岛266003 青岛双桃精细化工有限公司山东青岛266031 青岛科技大学山东青岛266042 山东出入境检验检疫局检验检疫技术中心山东青岛266001

塑料在食品接触材料中占有重要地位,通过介绍食品接触塑料材料中重金属危害及来源,总结食品接触塑料材料中有害重金属安全限量,并对目前食品接触塑料材料中有害重金属的迁移测定方法进行综述。开发食品接触材料快速检测方法是今后研究... 详细信息

塑料在食品接触材料中占有重要地位,通过介绍食品接触塑料材料中重金属危害及来源,总结食品接触塑料材料中有害重金属安全限量,并对目前食品接触塑料材料中有害重金属的迁移测定方法进行综述。开发食品接触材料快速检测方法是今后研究的方向。

关键词：食品接触塑料材料有害重金属迁移量测定方法

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Observer-based H∞ control for discrete-time stochastic systems with quantisation and random communication delays

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IET CONTROL THEORY AND APPLICATIONS 2013年第3期7卷 372-379页

作者： Yan, Huaicheng Su, Zhenzhen zhang, Hao Yang, fuwen E China Univ Sci & Technol Minist Educ Key Lab Adv Control & Optimisat Chem Proc Shanghai 200237 Peoples R China E China Univ Sci & Technol Sch Informat Sci & Engn Shanghai 200237 Peoples R China City Univ Hong Kong Dept Mfg Engn & Engn Management Kowloon Hong Kong Peoples R China Tongji Univ Dept Control Sci & Engn Shanghai 200092 Peoples R China

In this study, the authors are concerned with the observer-based quantised H-infinity control problem for a class of discrete-time stochastic systems with random communication delays. The system under consideration involves signals quantisation, state-dependent disturbance as well as random communication delays. The measured output and the control input quantisation are considered simultaneously by using the sector bound approach, while the random communication delays from the sensor to the controller and from the controller to the plant are modelled by a linear function of the stochastic variable satisfying Bernoulli random binary distribution. It is aimed at designing an observer-based controller such that the dynamics of the closed-loop system is guaranteed to be exponentially stable in the mean square, and a prescribed H-infinity disturbance attenuation level is also achieved. Finally, a simulation example is given to illustrate the effectiveness of the proposed method.

关键词： asymptotic stability closed loop systems control system synthesis delays discrete time systems Hâˆž control observers probability quantisation (signal) stochastic systems discrete-time stochastic systems random communication delays observer-based quantised Hâˆž control problem signal quantisation state-dependent disturbance control input quantisation measured output quantisation sector bound approach linear function stochastic variable Bernoulli random binary distribution closed-loop system exponential stability Hâˆž disturbance attenuation level simulation example mean square method

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Effect of China's rapid development on its iconic giant panda

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Chinese Science Bulletin 2013年第17期58卷 2134-2139页

作者： ZHU LiFeng HU YiBo zhang ZeJun WEI fuwen Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of Sciences

Anthropogenic factors affect biodiversity and have led to the contraction or extinction of animal populations ***,we use historical demographic data,spanning the past 300 years,to show that a rapid distributional contraction of giant pandas took place during the 18th and 19th centuries alongside the increase in human ***-use also underwent a significant change across the areas where giant pandas were found because of government agricultural policy and the introduction of new *** impact of social development on giant pandas includes habitat loss and fragmentation,and range *** findings would facilitate the design of effective conservation strategies that seek to conserve and increase current habitats of this iconic species,especially in areas that our analysis has identified as places where pandas have suffered from high human pressure.

关键词：大熊猫栖息地标志性中国经济保护策略生物多样性种群灭绝人为因素统计数据

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基于ARM的嵌入式电脑丝袜机控制系统设计

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针织工业 2014年第1期 22-25页

作者：张团善罗富文吴辉西安工程大学电子信息学院陕西西安710048

针对国内丝袜机计算机控制系统在稳定性、扩展性、可移植性等方面较差的问题,设计了一种基于ARM的嵌入式电脑丝袜机控制系统。在介绍控制系统的设计要求、基本原理及功能实现的基础上,提出了该系统采用ARM920T架构的32位工业级处理芯片S... 详细信息

针对国内丝袜机计算机控制系统在稳定性、扩展性、可移植性等方面较差的问题,设计了一种基于ARM的嵌入式电脑丝袜机控制系统。在介绍控制系统的设计要求、基本原理及功能实现的基础上,提出了该系统采用ARM920T架构的32位工业级处理芯片S3C2440A作为主控制器,采用ARM Cortex-M3内核的32位微处理器STM32F103作为现场总线的从节点控制器;并详细分析控制系统的工作流程,以及主控制器和底层功能模块的软、硬件实现方法。实践证明,该控制系统具有集成度高、稳定性好、实时性强等优点。

关键词：电脑丝袜机 ARM 控制系统嵌入式 CAN总线

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Surgical Technique: Hemilaminectomy and Unilateral Lateral Mass Fixation for Cervical Ossification of the Posterior Longitudinal Ligament Reply

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CLINICAL ORTHOPAEDICS AND RELATED RESEARCH 2013年第12期471卷 4094-4095页

作者： Liu, Kun Shi, Jiangang Jia, Lianshun Chen, fuwen zhang, Shuming Second Artillery Gen Hosp Dept Orthoped Surg Beijing Peoples R China Second Mil Med Univ Shanghai Chang Zheng Hosp Dept Orthoped Surg Shanghai 200003 Peoples R China

BACKGROUND:Surgical approaches for cervical ossification of the posterior longitudinal ligament (OPLL) include anterior, posterior, or combined decompression with or without fusion. The goal of surgery is to decompress the spinal cord while maintaining the stability and sagittal alignment of the cervical spine. C5 palsy has been reported as a postoperative complication of cervical laminectomy or laminoplasty characterized as motor weakness of the muscles supplied with C5 nerve roots. Several studies have shown this phenomenon was partially attributable to posterior shift of spinal cord.;METHODS:The rationale for choosing hemilaminectomy is to control postoperative posterior shift of the spinal cord and afford more stability by preserving ligamentous attachments and posterior bony elements as much as possible. After a fixation system of lateral mass screws and rods is installed unilaterally, laminae are removed from the underlying dura using a high-speed burr and Kerrison laminectomy rongeur on the other side. The spinous processes are preserved.;METHODS:Patients with multilevel continuous/mixed cervical OPLL are good candidates for this technique. We retrospectively reviewed 146 patients who had multilevel continuous/mixed cervical OPLL and underwent surgery from January 2006 to January 2010. Neurologic condition was evaluated using the improvement ratio (IR) of the Japanese Orthopaedic Association (JOA) score for cervical myelopathy.;RESULTS:The mean JOA score increased from 10 points before surgery to 14 points at last followup. The mean IR of neurologic function (JOA score) was 59%. C5 palsy was not observed in any patient after decompression, and cervical lordosis changed from 8.7° preoperatively to 9.1° at last followup.;CONCLUSIONS:For patients with multilevel continuous/mixed cervical OPLL without fixed kyphosis, multilevel hemilaminectomy with unilateral lateral mass fixation is an effective alternative technique.;METHODS:Level IV, therapeutic study. See Gui

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兰州市公交便捷性与新建住宅价格相关性研究

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现代城市研究 2014年第11期29卷 110-116页

作者：刘洋张志斌达福文陈志杰西北师范大学地理与环境科学学院

本文以兰州市主城区2008年至2013年新建楼盘和同期所有公交站点及线路为研究数据,以统一半径缓冲区中乘客所能选择的公交线路的数量作为楼盘公交便捷性优劣的评判依据,运用相关分析法计算出楼盘房价与公交便捷性之间的相关系数。结果表... 详细信息

本文以兰州市主城区2008年至2013年新建楼盘和同期所有公交站点及线路为研究数据,以统一半径缓冲区中乘客所能选择的公交线路的数量作为楼盘公交便捷性优劣的评判依据,运用相关分析法计算出楼盘房价与公交便捷性之间的相关系数。结果表明:(1)兰州市新建住宅价格与公交便捷性呈明显的正相关关系;(2)兰州市新建楼盘房价与公交便捷性间的相关性表现出四种类型,即以高房价-高便捷性(H-H)与低房价-低便捷性(L-L)类型为主,零星分布高房价-低便捷性(H-L)与低房价-高便捷性(L-H)类型楼盘;其中,H-H型楼盘向各自辖区的中心城区集聚分布特征明显,L-L型楼盘表现出向城市中心区外围扩散的边缘化分布;(3)兰州市新建住宅价格水平受到包括公共交通状况在内的多种因素的综合影响。

关键词：公交便捷性新建住宅房价相关类型兰州市

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