期刊文献+
共找到27,876篇文章
< 1 2 250 >
每页显示 20 50 100
Distributed event region fault-tolerance based on weighted distance for wireless sensor networks 被引量:2
1
作者 Li Ping Li Hong Wu Min 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第6期1351-1360,共10页
Event region detection is the important application for wireless sensor networks(WSNs), where the existing faulty sensors would lead to drastic deterioration of network quality of service.Considering single-moment n... Event region detection is the important application for wireless sensor networks(WSNs), where the existing faulty sensors would lead to drastic deterioration of network quality of service.Considering single-moment nodes fault-tolerance, a novel distributed fault-tolerant detection algorithm named distributed fault-tolerance based on weighted distance(DFWD) is proposed, which exploits the spatial correlation among sensor nodes and their redundant information.In sensor networks, neighborhood sensor nodes will be endowed with different relative weights respectively according to the distances between them and the central node.Having syncretized the weighted information of dual-neighborhood nodes appropriately, it is reasonable to decide the ultimate status of the central sensor node.Simultaneously, readings of faulty sensors would be corrected during this process.Simulation results demonstrate that the DFWD has a higher fault detection accuracy compared with other algorithms, and when the sensor fault probability is 10%, the DFWD can still correct more than 91% faulty sensor nodes, which significantly improves the performance of the whole sensor network. 展开更多
关键词 event region detection weighted distance distributed fault-tolerance wireless sensor network.
在线阅读 下载PDF
Imperfect preventive maintenance for numerical control machine tools with log-linear virtual age process 被引量:5
2
作者 郭俊锋 芮执元 +1 位作者 冯瑞成 魏兴春 《Journal of Central South University》 SCIE EI CAS 2014年第12期4497-4502,共6页
Based on the log-linear virtual age process, an imperfect preventive maintenance policy for numerical control(NC)machine tools with random maintenance quality is proposed. The proposed model is a combination of the Ki... Based on the log-linear virtual age process, an imperfect preventive maintenance policy for numerical control(NC)machine tools with random maintenance quality is proposed. The proposed model is a combination of the Kijima type virtual age model and the failure intensity adjustment model. Maintenance intervals of the proposed hybrid model are derived when the failure intensity increase factor and the restoration factor are both random variables with uniform distribution. The optimal maintenance policy in infinite time horizon is presented. A numerical example is given when the failures of NC machine tools are described by the log-linear process. Finally, a discussion is presented to show how the optimal results depend on the different cost parameters. 展开更多
关键词 reliability imperfect preventive maintenance virtual age log-linear process failure intensity
在线阅读 下载PDF
Progress in preventive effects of cordyceps sinensis on ischemic brain
3
作者 Xue BAI Yu-qing ZHAO +2 位作者 Chao-feng LI Yi-bo TANG Zhen-quan LIU 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2017年第10期985-986,共2页
Cerebral ischemia is due to cerebral blood supply disorders caused by ischemia and hypoxia resulting in localized ischemic brain necrosis or brain softening of the disease,leading to irreversible brain damage and subs... Cerebral ischemia is due to cerebral blood supply disorders caused by ischemia and hypoxia resulting in localized ischemic brain necrosis or brain softening of the disease,leading to irreversible brain damage and subsequent loss of neuronal function is a serious threat to human health One of several diseases.For patients with cerebral ischemia,often the lack of effective and extensive treatment.In addition,cerebral ischemia with morbidity,morbidity and mortality are characterized by high,so by the medical profession at home and abroad attention.As a traditional Chinese medicine,cordyceps sinensis(CS)is a complex of ergot fungus,which is parasitized on the larvae of the bat-moth family.The compound is composed of cordycepin,cordyceps polysaccharide,cordyceps sinensis peptides,ergosterol,mannitol,fatty acids and trace elements such as a variety of ingredients,with a wide range of pharmacological effects.Over the years,domestic and foreign scholars on the pharmacological effects of cordyceps sinensis were more comprehensive study of its prevention and treatment of cerebral ischemia is also deepening,found that cordyceps sinensis on cerebral ischemia with anti-inflammatory,reduce oxidative damage and neuronal ischemia damage,reduce neuronal apoptosis,improve memory cognition,reduce thrombosis,inhibit NO production,enhance mitochondrial energy supply,scavenging free radicals and other prevention and treatment.But no relevant review.In this paper,the domestic and foreign literatures on the prevention and treatment of cerebral ischemia by cordyceps sinensis were summarized,analyzed and summarized in order to provide useful information for the research and further development of cordyceps sinensis. 展开更多
关键词 cordyceps sinensis cerebral ischemia preventive effect PROGRESS
在线阅读 下载PDF
Self Fault-Tolerance of Protocols: A Case Study
4
作者 Li, Layuan Li, Chunlin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2000年第3期28-34,共7页
The prerequisite for the existing protocols' correctness is that protocols can be normally operated under the normal conditions, rather than dealing with abnormal conditions. In other words, protocols with the fau... The prerequisite for the existing protocols' correctness is that protocols can be normally operated under the normal conditions, rather than dealing with abnormal conditions. In other words, protocols with the fault-tolerance can not be provided when some fault occurs. This paper discusses the self fault-tolerance of protocols. It describes some concepts and methods for achieving self fault-tolerance of protocols. Meanwhile, it provides a case study, investigates a typical protocol that does not satisfy the self fault-tolerance, and gives a new redesign version of this existing protocol using the proposed approach. 展开更多
关键词 Protocols Self fault-tolerance Formal method Multimedia communications Protocol engineering.
在线阅读 下载PDF
Fault-tolerant control strategies for tilt-rotor aerial-aquatic vehicles:Design and implementation 被引量:1
5
作者 Sihuan Wu Sifan Wu +3 位作者 Maosen Shao Zhilin He Yuan Liu Jinxiu Zhang 《Defence Technology(防务技术)》 2025年第9期274-293,共20页
The cross-domain capabilities of aerial-aquatic vehicles(AAVs)hold significant potential for future airsea integrated combat operations.However,the failure rate of AAVs is higher than that of unmanned systems operatin... The cross-domain capabilities of aerial-aquatic vehicles(AAVs)hold significant potential for future airsea integrated combat operations.However,the failure rate of AAVs is higher than that of unmanned systems operating in a single medium.To ensure the reliable and stable completion of tasks by AAVs,this paper proposes a tiltable quadcopter AAV to mitigate the potential issue of rotor failure,which can lead to high-speed spinning or damage during cross-media transitions.Experimental validation demonstrates that this tiltable quadcopter AAV can transform into a dual-rotor or triple-rotor configuration after losing one or two rotors,allowing it to perform cross-domain movements with enhanced stability and maintain task completion.This enhancement significantly improves its fault tolerance and task reliability. 展开更多
关键词 Aerial-aquatic vehicle Tiltable quadcopter fault-tolerance Cross-media operation
在线阅读 下载PDF
Fault-tolerant control for diesel engine air path system via sliding mode surface
6
作者 WU Wen-jie ZHANG Yi-xin +4 位作者 WANG Xing-jian WANG Shao-ping ZHANG Jian ZHENG Wei TAO Mo 《控制理论与应用》 北大核心 2025年第8期1570-1577,共8页
The operating environment of the diesel engine air path system is complex and may be affected by external random disturbances.Potentially leading to faults.This paper addresses the fault-tolerant control problem of th... The operating environment of the diesel engine air path system is complex and may be affected by external random disturbances.Potentially leading to faults.This paper addresses the fault-tolerant control problem of the diesel engine air path system,assuming that the system may simultaneously be affected by actuator faults and external random disturbances,a disturbance observer-based sliding mode controller is designed.Through the linear matrix inequality technique for solving observer and controller gains,optimal gain matrices can be obtained,eliminating the manual adjustment process of controller parameters and reducing the chattering phenomenon of the sliding mode surface.Finally,the effectiveness of the proposed method is verified through simulation analysis. 展开更多
关键词 disel engine air path fault-tolerant control sliding mode control disturbance observer
在线阅读 下载PDF
“卫生健康现代化”视角下江西省医防融合的重大慢性病管理模式及实施路径研究
7
作者 李丽清 万嘉雯 +1 位作者 曾传美 林慧英 《中国全科医学》 北大核心 2026年第3期340-347,共8页
背景党的二十大报告指出,要坚持预防为主,加强重大慢性病健康管理,提高基层防病治病和健康管理能力。面对慢性病高发和新发突发传染病的双重挑战,传统的“重治轻防”模式已难以满足人民日益增长的健康需求。江西省出台《关于加快推进卫... 背景党的二十大报告指出,要坚持预防为主,加强重大慢性病健康管理,提高基层防病治病和健康管理能力。面对慢性病高发和新发突发传染病的双重挑战,传统的“重治轻防”模式已难以满足人民日益增长的健康需求。江西省出台《关于加快推进卫生健康现代化的若干意见》和《江西省建设新时代卫生健康“四区四高地”行动方案(2024-2027年)》,将卫生健康现代化纳入全省发展战略,制定一系列制度举措。目的本研究围绕重大慢性病管理,系统分析当前医防融合的主要趋势,探讨江西省当前慢性病管理面临的五大挑战:政策工具供需不平衡、管理部门协同不足、部门协作不畅、人才保障不均、患者自我管理积极性不足。方法结合国内部分省市的实践经验,提出宜春万载“1+2+3”模式、九江“院办院管”模式、萍乡紧密型医共体模式和上饶婺源“项目+网格化”模式,凝练出4种可推广的医防融合路径。结果研究总结出江西省4种具有代表性的慢性病管理模式:(1)宜春万载“1+2+3”一体化管理模式,以家庭医生签约为纽带,构建预防—诊治—康复闭环服务体系;(2)九江“院办院管”中医药特色防治模式,通过公立医院直管社区卫生中心,实现中医药适宜技术与慢病防控深度融合;(3)萍乡紧密型医共体模式,依托区、乡、村三级联动和信息化支撑,推动优质资源下沉与慢性病管理同频共治;(4)上饶婺源“项目+网格化”模式,以H型高血压防控项目为抓手,构建政府主导、部门协同、网格化管理的慢病防控网络。进一步凝练出江西省慢性病医防融合的4条实施路径:治理体系协同化、一体化管理精细化、中医药赋能多元化、医共体联动高效化。结论江西省在推进医防融合慢性病管理方面已初步形成可复制、可推广的多元模式,但仍面临政策供需不平衡、跨部门协作不畅、人才保障不足及患者自我管理意识薄弱等问题。未来应从完善顶层设计、强化政策协同、优化医防一体化机制、发挥中医药优势和信息化支撑等方面着手,促进慢性病管理体系高质量发展,助力实现江西卫生健康现代化目标。 展开更多
关键词 卫生健康现代化 医防融合 慢性病 健康管理 健康促进
在线阅读 下载PDF
PreVent GC系统提高多环芳烃致突变物检出量的研究 被引量:1
8
作者 徐维并 佟柏龄 《环境化学》 CAS CSCD 北大核心 2000年第5期466-469,共4页
采用PreVent预排/切割气相色谱(GC)进样技术,对多种多环芳烃(PAHs)致突变物质进行大体积进样(LVI)分析,并与常现毛细管色谱进样方式进行比较,最大进样量为125μl,检测灵敏度可提高0.5—2个数量级以上,检测精度一般<5%.
关键词 预排 切割 进样 多环芳烃 致突变物 气相色谱
在线阅读 下载PDF
青年冠状动脉疾病的早期筛查和预防专家共识
9
作者 中国医药教育协会心血管内科专业委员会 中国医疗保健国际交流促进会心血管健康医学分会 +5 位作者 王炎 丁虎 杨德业 李建平 汪璐芸 张龙 《中国全科医学》 北大核心 2026年第2期137-147,共11页
青年人群(<45岁)冠状动脉疾病涵盖冠状动脉粥样硬化、痉挛、炎症、栓塞、自发性夹层、动脉瘤、物理化学性损伤、发育或引流异常等;其中,冠状动脉粥样硬化导致的缺血性心脏病(冠心病)最常见。本共识针对当前青年冠状动脉疾病的现状,... 青年人群(<45岁)冠状动脉疾病涵盖冠状动脉粥样硬化、痉挛、炎症、栓塞、自发性夹层、动脉瘤、物理化学性损伤、发育或引流异常等;其中,冠状动脉粥样硬化导致的缺血性心脏病(冠心病)最常见。本共识针对当前青年冠状动脉疾病的现状,重点阐述青年冠心病的流行病学、危险因素、诊断、筛查方法及预防策略,并特别强调早期筛查的重要性。建议对特定人群(如具有早发冠心病家族史、代谢综合征、慢性免疫介导的炎症性疾病患者及肾功能不全患者等)进行血脂、血糖、肾功能等常规检测,并结合基因检测(如家族性高胆固醇血症相关基因)进行定期评估。预防策略以生活方式干预为核心,包括低盐低脂饮食、规律运动、戒烟限酒、睡眠管理及防护空气污染。同时,推荐遵循指南进行血脂、血糖、高同型半胱氨酸及高血压的防控。此外,针对慢性肾脏病、慢性免疫介导炎症性疾病等,需监测生物标志物并实施精准干预。共识指出,当前关于青年冠心病研究证据仍显不足,未来需加强在风险分层、筛查频率及治疗策略方面的循证医学研究,并通过多学科协作与公众教育,有效降低青年冠心病的发病率和疾病负担。 展开更多
关键词 冠状动脉疾病 冠状动脉粥样硬化性心脏病 青壮年 早期筛查 风险评估 预防和管理
在线阅读 下载PDF
1990-2021年中国肺癌发病和死亡趋势分析及2035年预测研究
10
作者 杨清惠 胡映雪 +1 位作者 倪萍蔚 刘晓 《中国全科医学》 北大核心 2026年第2期256-263,共8页
背景肺癌是全球重大公共卫生问题,中国作为肺癌负担较重的国家之一,其发病与死亡趋势受环境、经济及行为因素的多重影响,且存在显著区域异质性。解析肺癌疾病负担的时空驱动机制并提出精准防控策略,对实现“健康中国2030”目标至关重要... 背景肺癌是全球重大公共卫生问题,中国作为肺癌负担较重的国家之一,其发病与死亡趋势受环境、经济及行为因素的多重影响,且存在显著区域异质性。解析肺癌疾病负担的时空驱动机制并提出精准防控策略,对实现“健康中国2030”目标至关重要。目的分析并预测1990—2021年中国肺癌发病并死亡趋势,探讨区域环境与经济因素对肺癌流行趋势的空间异质性影响,提出精准防控建议。方法基于全球疾病负担(GBD)数据,提取中国1990—2021年不同性别、年龄的肺癌发病和死亡人数、年龄标化发病率及年龄标化死亡率数据。采用年龄-时期-队列模型、联结点回归(JPR)模型及Holt指数平滑模型识别趋势转折点;整合环境(PM_(2.5)、工业污染)、经济(人均GDP、医疗资源)数据,利用空间杜宾模型解析区域异质性;通过Holt指数平滑模型预测2035年肺癌发病与死亡趋势。结果JPR模型显示1990—2021年中国肺癌年龄标化发病率年均增长0.94%(95%CI=0.87%~1.01%),年龄标化死亡率增长0.38%(95%CI=0.31%~0.45%);肺癌发病率呈现空间聚集性(P<0.05),京津冀、黑吉辽及四川省为高风险地区。空间杜宾模型显示,PM_(2.5)暴露(β=1.15,95%CI=1.02~1.28)、工业废气排放量大(β=0.89,95%CI=0.75~1.03)是肺癌发病的危险因素(P<0.05),而人均GDP高(β=-0.62,95%CI=-0.78~-0.46)和三级医院密度高(β=-0.74,95%CI=-0.89~-0.59)是肺癌发病的保护因素(P<0.05)。预测到2035年,全国肺癌年龄标化发病率将达46.18/10万,年龄标化死亡率将达到38.26/10万,2022—2035年女性的肺癌发病和死亡趋势可能进一步上升,而男性的变化趋势较为平缓。结论中国肺癌疾病负担呈现“北高南低”的空间分异特征,环境暴露与医疗资源不均是关键驱动因素。建议针对高风险区域(北方工业区)及人群(女性患者)实施精准筛查,以降低健康不平等,助力国家癌症防控目标实现。 展开更多
关键词 肺癌 发病趋势 死亡趋势 环境暴露 高风险亚群 精准防控
在线阅读 下载PDF
“全-专”分级精准管理对2型糖尿病低血糖的防治效应:一项随机对照研究
11
作者 马腾腾 诸秉根 《中国全科医学》 北大核心 2026年第3期331-339,共9页
背景随着糖尿病发病率不断升高,强化降糖治疗策略广泛普及,低血糖的发生率随之增加,低血糖的危害及防治是临床亟待解决的重大问题。目的探究“全-专”分级精准管理模式对社区2型糖尿病低血糖患者身心健康的影响。方法选取2023年1—7月... 背景随着糖尿病发病率不断升高,强化降糖治疗策略广泛普及,低血糖的发生率随之增加,低血糖的危害及防治是临床亟待解决的重大问题。目的探究“全-专”分级精准管理模式对社区2型糖尿病低血糖患者身心健康的影响。方法选取2023年1—7月于上海市浦东新区上钢社区卫生服务中心就诊的半年内有低血糖发作史的2型糖尿病患者为研究对象,采用随机数字表法将患者分为对照组和试验组,每组60例。对照组进行常规管理;试验组纳入“全-专”分级精准管理模式,依据患者低血糖严重程度和实际情况,分至全科门诊、专病门诊或转至上级医院就诊,并给予实时数据驱动的精准管理、心理干预、全面宣教及引入家庭支持系统等综合管理。干预6个月后,比较干预后两组血糖控制指标[空腹血糖(FPG)、糖化血红蛋白(HbA_(1c))、目标范围内时间(TIR)及血糖变异系数(CV)]、低血糖发生次数(总次数、轻度、中度、重度)、中文版低血糖恐惧-忧虑量表(CHFSⅡ-WS)评分、糖尿病患者生存质量特异性量表(DSQL)总分及各维度评分。评估“全-专”分级精准管理模式对2型糖尿病低血糖患者血糖控制和恐惧情绪的影响,进而评价该管理模式对社区2型糖尿病患者低血糖管理的意义。结果干预期间,因住址更换,试验组1人失访。重复测量方差分析结果表明,组别和时间对BMI、腰围不存在交互作用(F_(交互)=1.922、1.134,P_(交互)=0.162、0.320);时间对BMI、腰围主效应显著(F_(时间)=7.507、4.097,P_(时间)=0.003、0021);组别对BMI、腰围主效应不显著(F_(组间)=0.598、0.138,P_(组间)=0.441、0.711)。组别和时间对收缩压和舒张压不存在交互作用(F_(交互)=0.868、0.151,P_(交互)=0.419、0.860);时间和组别对BMI、腰围主效应不显著(F_(时间)=1.295、1.267,P=0.276、0.284;F_(组间)=1.750、0.337,P_(组间)=0.188、0.562)。组别和时间对FPG、HbA_(1c)、CV存在交互作用(F_(交互)=36.662、15.157、10.767,P_(交互)<0.001);时间和组别分别对FPG、HbA_(1c)、CV主效应显著(F_(时间)=105.098、60.155、41.307,P_(时间)<0.001;F_(组间)=6.916、4.357、4.094,P_(组间)=0.010、0.039、0.045)。组别和时间对TIR存在交互作用(F_(交互)=4.767,P_(交互)=0.012);时间对TIR主效应显著(F_(时间)=13.456,P_(时间)<0.001);组别对TIR主效应不显著(F_(组间)=3.405,P_(组间)=0.068)。干预6个月后,试验组患者近半年低血糖发生总次数、轻度及中度低血糖发生次数均低于对照组(P<0.05)。干预6个月后试验组患者CHFSⅡ-WS评分、DSQL总分及各维度得分均低于对照组(P<0.05)。试验组干预6个月后CHFSⅡ-WS评分、DSQL总分及各维度得分均低于同组干预前(P<0.05)。结论“全-专”分级精准管理模式通过系统化的管理与干预能够改善患者的血糖控制水平,减少血糖波动,降低低血糖发生风险,提升社区2型糖尿病低血糖管理水平及效率。该管理模式有助于缓解患者对低血糖的恐惧情绪,改善患者自我管理能力,提升患者生存质量。 展开更多
关键词 2型糖尿病 低血糖 社区管理 “全-专”分级精准管理 防治效应
在线阅读 下载PDF
Time-varying fault-tolerant formation tracking based cooperative control and guidance for multiple cruise missile systems under actuator failures and directed topologies 被引量:10
12
作者 XU Xingguang WEI Zhenyan +1 位作者 REN Zhang LI Shusheng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第3期587-600,共14页
This paper studies time-varying fault-tolerant formation tracking problems for the multiple cruise missile system under directed topologies subjected to actuator failures. Firstly, the timevarying fault-tolerant forma... This paper studies time-varying fault-tolerant formation tracking problems for the multiple cruise missile system under directed topologies subjected to actuator failures. Firstly, the timevarying fault-tolerant formation tracking process for the multiple cruise missile system is divided into the guidance loop and the control loop. Then protocols are constructed to accomplish distributed fault-tolerant formation tracking in the guidance loop with the adaptive updating mechanism, in the condition where neither the knowledge about actuator malfunctions nor any global information of the communication topology remains available. Moreover, sufficient conditions to accomplish formation tracking are presented, and it is shown that the multiple cruise missile system can carry on the predefined time-varying fault-tolerant control (FTC) formation tracking through the active disturbances rejection controller (ADRC) and the proportion integration (PI) controller by the way of the fault-tolerant protocol utilizing the designed strategies, in the event of actuator failures. At last, numerical analysis and simulation are designed to verify the theoretical results. 展开更多
关键词 fault-tolerANT formation tracking consensus-based CRUISE MISSILE active disturbances REJECTION controller (ADRC)
在线阅读 下载PDF
Output feedback based adaptive robust fault-tolerant control for a class of uncertain nonlinear systems 被引量:6
13
作者 Shreekant Gayaka Bin Yao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第1期38-51,共14页
An adaptive robust approach for actuator fault-tolerant control of a class of uncertain nonlinear systems is proposed.The two chief ways in which the system performance can degrade following an actuator-fault are unde... An adaptive robust approach for actuator fault-tolerant control of a class of uncertain nonlinear systems is proposed.The two chief ways in which the system performance can degrade following an actuator-fault are undesirable transients and unacceptably large steady-state tracking errors.Adaptive control based schemes can achieve good final tracking accuracy in spite of change in system parameters following an actuator fault,and robust control based designs can achieve guaranteed transient response.However,neither adaptive control nor robust control based fault-tolerant designs can address both the issues associated with actuator faults.In the present work,an adaptive robust fault-tolerant control scheme is claimed to solve both the problems,as it seamlessly integrates adaptive and robust control design techniques.Comparative simulation studies are performed using a nonlinear hypersonic aircraft model to show the effectiveness of the proposed scheme over a robust adaptive control based faulttolerant scheme. 展开更多
关键词 fault-tolerant system actuator fault adaptive control robust control.
在线阅读 下载PDF
Backstepping-based active fault-tolerant control for a class of uncertain SISO nonlinear systems 被引量:6
14
作者 Meng Lingya Jiang Bin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第6期1263-1270,共8页
Active fault-tolerant control is investigated for a class of uncertain SISO nonlinear flight control systems based on the adaptive observer, feedback linearization and backstepping theory.Firstly an adaptive observer ... Active fault-tolerant control is investigated for a class of uncertain SISO nonlinear flight control systems based on the adaptive observer, feedback linearization and backstepping theory.Firstly an adaptive observer is constructed to estimate the fault in the faulty system.A new fault updating law is presented to simplify the assumption conditions of the adaptive observer.The asymptotical stability of the observer and the uniform ultimate boundedness of the fault estimation error are guaranteed by Lyapunov theorem.Then a backstepping-based active fault-tolerant controller is designed for the faulty system.The asymptotical stability of the closed-loop system and uniform ultimate boundedness of the tracking error are proved based on Lyapunov theorem.The effectiveness of the proposed scheme is demonstrated through the numerical simulation of a flight control system. 展开更多
关键词 fault-tolerant control fault diagnosis NONLINEAR BACKSTEPPING adaptive observer flight control.
在线阅读 下载PDF
Intelligent fault-tolerant algorithm with two-stage and feedback for integrated navigation federated filtering 被引量:6
15
作者 Li Cong Honglei Qin Zhanzhong Tan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第2期274-282,共9页
In order to take full advantage of federated filter in fault-tolerant design of integrated navigation system, the limitation of fault detection algorithm for gradual changing fault detection and the poor fault toleran... In order to take full advantage of federated filter in fault-tolerant design of integrated navigation system, the limitation of fault detection algorithm for gradual changing fault detection and the poor fault tolerance of global optimal fusion algorithm are the key problems to deal with. Based on theoretical analysis of the influencing factors of federated filtering fault tolerance, global fault-tolerant fusion algorithm and information sharing algorithm are proposed based on fuzzy assessment. It achieves intelligent fault-tolerant structure with two-stage and feedback, including real-time fault detection in sub-filters, and fault-tolerant fusion and information sharing in main filter. The simulation results demonstrate that the algorithm can effectively improve fault-tolerant ability and ensure relatively high positioning precision of integrated navigation system when a subsystem having gradual changing fault. 展开更多
关键词 integrated navigation federated filter fuzzy assess-ment fault-tolerant fusion information sharing.
在线阅读 下载PDF
Research on robust fault-tolerant control for networked control system with packet dropout 被引量:50
16
作者 Huo Zhihong Fang Huajing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第1期76-82,共7页
A kind of networked control system with network-induced delay and packet dropout, modeled on asynchronous dynamical systems was tested, and the integrity design of the networked control system with sensors failures an... A kind of networked control system with network-induced delay and packet dropout, modeled on asynchronous dynamical systems was tested, and the integrity design of the networked control system with sensors failures and actuators failures was analyzed using hybrid systems technique based on the robust fault-tolerant control theory. The parametric expression of controller is given based on the feasible solution of linear matrix inequality. The simulation results are provided on the basis of detailed theoretical analysis, which further demonstrate the validity of the proposed schema. 展开更多
关键词 Networked control system (NCS) fault-tolerant control (FTC) Asynchronous dynamical systems (ADS) Integrity design Packet dropout Time delay
在线阅读 下载PDF
Fault-Tolerant Control Research for Networked Control System under Communication Constraints 被引量:11
17
作者 HUO Zhi-Hong FANG Hua-Jing 《自动化学报》 EI CSCD 北大核心 2006年第5期659-666,共8页
Implementing a control system over a communication network induces inevitable time delays that may degrade performance and even cause instability. One of the most effective ways to reduce the negative effect of delays... Implementing a control system over a communication network induces inevitable time delays that may degrade performance and even cause instability. One of the most effective ways to reduce the negative effect of delays on the performance of networked control system (NCS) is to reduce network traffic. In this paper, adjustable deadbands are explored as a solution to reduce network traffic in NCS. A method of fault-tolerant control of networked control system is presented, which takes into account system response as well as network traffic. The integrity design for a kind of NCS with sensor failures and actuator failures is analyzed based on robust fault-tolerant control theory and information scheduling. After detailed theoretical analysis, the paper also provides the simulation results, which further validate the proposed scheme. 展开更多
关键词 Networked control system (NCS) deadbands fault-tolerant control (FTC) integrity design time delay
在线阅读 下载PDF
Adaptive fault-tolerant control based on boundary estimation for space robot under joint actuator faults and uncertain parameters 被引量:5
18
作者 Rong-Hua Lei Li Chen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第6期964-971,共8页
Since the joint actuator of the space robot executes the control instructions frequently in the harsh space environment,it is prone to the partial loss of control effectiveness(PLCE)fault.An adaptive fault-tolerant co... Since the joint actuator of the space robot executes the control instructions frequently in the harsh space environment,it is prone to the partial loss of control effectiveness(PLCE)fault.An adaptive fault-tolerant control algorithm is designed for a space robot system with the uncertain parameters and the PLCE actuator faults.The mathematical model of the system is established based on the Lagrange method,and the PLCE actuator fault is described as an effectiveness factor.The lower bound of the effectiveness factors and the upper bound of the uncertain parameters are estimated by an adaptive strategy,and the estimated value is fed back to the control algorithm.Compared with the traditional fault-tolerant algorithms,the proposed algorithm does not need to predetermine the lower bound of the effectiveness factor,hence it is more in line with the actual engineering application.It is proved that the algorithm can guarantee the stability of the closed-loop system based on the Lyapunov function method.The numerical simulation results show that the proposed algorithm can not only compensate for the uncertain parameters,but also can tolerate the PLCE actuator faults effectively,which verifies the effectiveness and superiority of the control scheme. 展开更多
关键词 Space robot Actuator faults Uncertain parameters Effectiveness factor fault-tolerant control
在线阅读 下载PDF
Robust H_∞ guaranteed cost satisfactory fault-tolerant control for discrete-time systems with quadratic D stabilizability 被引量:5
19
作者 Xiaodong Han Jiangong Liu +2 位作者 Dexiao Xie Dengfeng Zhang Zhiquan Wang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第3期496-502,共7页
The problem of robust H∞ guaranteed cost satisfactory fault-tolerant control with quadratic D stabilizability against actuator failures is investigated for a class of discrete-time systems with value-bounded uncertai... The problem of robust H∞ guaranteed cost satisfactory fault-tolerant control with quadratic D stabilizability against actuator failures is investigated for a class of discrete-time systems with value-bounded uncertainties existing in both the state and control input matrices.Based on a more practical and general model of actuator continuous gain failures,taking the transient property,robust behaviour on H∞ performance and quadratic cost performance requirements into consideration,sufficient conditions for the existence of satisfactory fault-tolerant controller are given and the effective design steps with constraints of multiple performance indices are provided.Meanwhile,the consistency of the regional pole index,H∞ norm-bound constraint and cost performance indices is set up for fault-tolerant control.A simulation example shows the effectiveness of the proposed method. 展开更多
关键词 fault-tolerant control actuator failures consistency theory quadratic D stabilizability.
在线阅读 下载PDF
Can Stomach Cancer be Prevented by Dietary Change: Preliminary Summary of Comparative Etiologic Study and Prevention 被引量:2
20
作者 张荫昌 林慧芝 +7 位作者 孙中行 白希文 Kunio Aoki Keiichi Kawai Ryuichiro Sasaki Yasunari Tsuchihashi Yoshinori Ito Nouki Watanabe 《中国医科大学学报》 CAS CSCD 1990年第S1期25-32,共8页
During 1984 to 1990, a comparative etiologic studyand primary prevention for stomach cancer was carriedout in a high risk area in Zhuanghe County of LiaoningProvince. Because of the increase of consumption of fr-esh v... During 1984 to 1990, a comparative etiologic studyand primary prevention for stomach cancer was carriedout in a high risk area in Zhuanghe County of LiaoningProvince. Because of the increase of consumption of fr-esh vegetables and fruits (Protective factors), decreaseof eating salted pork and fishes which was verified tohave strong mutagenecity (risk factors), acute inflamma-tion and erosions accompanying with chronic gastritis havegot striking improvement. At the same time, serum betac-arotene also raised gradually. The authors stressed thatimprovement of economic situation and dietary habits mayplay an important role in primary prevention of precurso-res of stomach cancer but decrease of incidence of thiscancer is an event of 30 years or more later as the letentperiod of stomach cancer is rather long. 展开更多
关键词 GASTRIC cancer high risk area DIETARY HABIT primary preventION
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部