期刊文献+
共找到11篇文章
< 1 >
每页显示 20 50 100
Relaxed Stability Criteria for Time-Delay Systems:A Novel Quadratic Function Convex Approximation Approach
1
作者 Shenquan Wang Wenchengyu Ji +2 位作者 Yulian Jiang Yanzheng Zhu Jian Sun 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第4期996-1006,共11页
This paper develops a quadratic function convex approximation approach to deal with the negative definite problem of the quadratic function induced by stability analysis of linear systems with time-varying delays.By i... This paper develops a quadratic function convex approximation approach to deal with the negative definite problem of the quadratic function induced by stability analysis of linear systems with time-varying delays.By introducing two adjustable parameters and two free variables,a novel convex function greater than or equal to the quadratic function is constructed,regardless of the sign of the coefficient in the quadratic term.The developed lemma can also be degenerated into the existing quadratic function negative-determination(QFND)lemma and relaxed QFND lemma respectively,by setting two adjustable parameters and two free variables as some particular values.Moreover,for a linear system with time-varying delays,a relaxed stability criterion is established via our developed lemma,together with the quivalent reciprocal combination technique and the Bessel-Legendre inequality.As a result,the conservatism can be reduced via the proposed approach in the context of constructing Lyapunov-Krasovskii functionals for the stability analysis of linear time-varying delay systems.Finally,the superiority of our results is illustrated through three numerical examples. 展开更多
关键词 equivalent reciprocal combination technique quadratic function convex approximation approach STABILITY timevarying delay
下载PDF
Feedback Stabilization over Wireless Network Using Adaptive Coded Modulation 被引量:5
2
作者 Li Yang Xin-Ping Guan +1 位作者 Cheng-Nian Long Xiao-Yuan Luo 《International Journal of Automation and computing》 EI 2008年第4期381-388,共8页
In this paper,we apply adaptive coded modulation (ACM) schemes to a wireless networked control system (WNCS) to improve the energy efficiency and increase the data rate over a fading channel.To capture the characteris... In this paper,we apply adaptive coded modulation (ACM) schemes to a wireless networked control system (WNCS) to improve the energy efficiency and increase the data rate over a fading channel.To capture the characteristics of varying rate, interference,and routing in wireless transmission channels,the concepts of equivalent delay (ED) and networked condition index (NCI) are introduced.Also,the analytic lower and upper bounds of EDs are obtained.Furthermore,we model the WNCS as a multicontroller switched system (MSS) under consideration of EDs and loss index in the wireless transmission.Sufficient stability condition of the closed-loop WNCS and corresponding dynamic state feedback controllers are derived in terms of linear matrix inequality (LMI). Numerical results show the validity and advantage of our proposed control strategies. 展开更多
关键词 Wireless networked control system (WNCS) adaptive coded modulation (ACM) equivalent delay (ed) networked condition index (NCI) multicontroller switched system (MSS) stability.
下载PDF
Analysis and Design of Wireless Networked Control System Utilizing Adaptive Coded ModulationAnalysis and Design of Wireless Networked Control System Utilizing Adaptive Coded Modulation 被引量:4
3
作者 YANG Li GUAN Xin-Ping LONG Cheng-Nian LUO Xiao-Yuan 《自动化学报》 EI CSCD 北大核心 2009年第7期911-918,共8页
关键词 无线网络控制系统 计算机技术 自动化系统 网络条件
下载PDF
Determination of median effective dose(ED_(50)) of scorpion antivenom against scorpion envenomation using a newly developed formula
4
作者 Saganuwan Alhaji Saganuwan 《Animal Models and Experimental Medicine》 2018年第3期228-234,共7页
Background: About 50 species of scorpions cause fatal scorpionism worldwide.Most of these are members of the Buthidae family, and include, among others,Mesobuthus eupeus, Androctonus crassicauda, Leiurus abdullahbayra... Background: About 50 species of scorpions cause fatal scorpionism worldwide.Most of these are members of the Buthidae family, and include, among others,Mesobuthus eupeus, Androctonus crassicauda, Leiurus abdullahbayrami, Leiurus quinquestriatus, Tityus pachyurus and Androctonus australis. Because high doses of scorpion venom and antivenom can cause death and hypersensitive reactions, there is a need to develop a formula that can be used to calculate both lethal and effective doses for scorpion venom and antivenom, respectively, thereby obviating the need for laboratory experiments.Methods: In view of this, a literature search was carried out with the aim of modifying the formula(LD_(50)=ED_(50)/3× W_a × 10^(-4))for calculation of the median lethal dose(LD_(50)) of scorpion venom and the ED_(50) of antivenom. The human equivalent dose(HED) formula was assessed for extrapolation of LD_(50) and ED_(50) from animals to human for comparison and relevance with the new formula.Results: The findings showed that the newly developed formula(LD_(50)= ED_(50)^(1/3)×W_a× 10^(-4)) yielded results that are very close to the reported values. Therefore, the newly developed and HED formulas can be used for calculation of LD_(50) and ED_(50) values for scorpion venom and antivenom, respectively.Conclusion: The new formula yielded better results than the HED formula, confirming its predictive validity, precision, and reliability, thereby obviating the need for rigorous experiments and justifying the principles of reduction, refinement, and replacement(3 Rs). 展开更多
关键词 ANTIVENOM ed50 human equivalent dose LD50 SCORPION VENOM
下载PDF
基于SOPC组件的高精度可编程延时电路 被引量:3
5
作者 李太全 孙先松 《微计算机信息》 北大核心 2008年第29期291-292,共2页
将可编程计数器和高精度延时器MC100EP196相结合,实现了延时器的大范围、高精度调节。在EP1C6Q240内将可编程计数器和MC100EP196控制电路制作成SOPC组件,通过Avalon总线与NIOSII连接,实现了可编程延时器的扫描控制。通过该设计驱动的采... 将可编程计数器和高精度延时器MC100EP196相结合,实现了延时器的大范围、高精度调节。在EP1C6Q240内将可编程计数器和MC100EP196控制电路制作成SOPC组件,通过Avalon总线与NIOSII连接,实现了可编程延时器的扫描控制。通过该设计驱动的采样电路测试结果,说明了电路的可行性。 展开更多
关键词 可编程延时器 可编程计数器 等效采样
下载PDF
地质雷达测控系统的FPGA实现 被引量:2
6
作者 李太全 陈威 《自动化仪表》 CAS 北大核心 2014年第4期18-20,共3页
超宽带地质雷达测控系统的关键是等效时间采样系统的实现,而等效时间采样需要一个精确的可编程延时器。利用Cyclone III、IV的锁相环(PLL)模块的动态相位调整功能,实现了最小步长125 ps的可编程延时器,可完成高达8 GS/s的等效采样,并开... 超宽带地质雷达测控系统的关键是等效时间采样系统的实现,而等效时间采样需要一个精确的可编程延时器。利用Cyclone III、IV的锁相环(PLL)模块的动态相位调整功能,实现了最小步长125 ps的可编程延时器,可完成高达8 GS/s的等效采样,并开发了相应的测控模块。测控模块通过Avalon总线与软核NIOS II连接,在NIOS II的控制下实现地质雷达的扫描控制。该设计具有结构紧凑、性能稳定、成本低廉等优点,适用于低频段地质雷达。试验测试证明了系统的可行性。 展开更多
关键词 地质雷达 可编程延时器 等效采样 现场可编程门阵列(FPGA) 动态相位调整
下载PDF
基于双向流固耦合的错位六弯叶桨搅拌特性 被引量:2
7
作者 栾德玉 郑深晓 +1 位作者 张盛峰 鲁建平 《石油化工设备技术》 CAS 2017年第3期45-49,共5页
基于ANSYS Workbench分析平台,采用双向流固耦合计算方法,对六弯叶桨(6BT)和错位六弯叶桨(6PBT)搅拌性能进行了对比分析,根据桨叶与流体之间相互耦合运动特性,考察了桨叶的等效应力和变形量的分布,探讨了流场结构对混合效率的影响。结... 基于ANSYS Workbench分析平台,采用双向流固耦合计算方法,对六弯叶桨(6BT)和错位六弯叶桨(6PBT)搅拌性能进行了对比分析,根据桨叶与流体之间相互耦合运动特性,考察了桨叶的等效应力和变形量的分布,探讨了流场结构对混合效率的影响。结果表明:速度矢量的计算值与PIV实验值吻合较好,基于双向流固耦合计算模型的数据结果可靠;同6BT桨相比,6PBT桨叶端部应力提高了51%,根部应力降低了22.2%,应力分布更趋均匀化,可有效提高桨叶强度,增强能量传递,而总变形量与6BT桨基本相同;6PBT桨能够产生不对称流场结构,混合时间明显降低,混合效率显著提高,其中6PBT桨的单位体积混合能只有6BT桨48%,体现出错位桨的优越性,这可为搅拌器的优化设计提供理论参考。 展开更多
关键词 错位六弯叶桨 流固耦合 等效应力 变形 混合效率
下载PDF
2例铥170内污染人员摄入量及内照射剂量估算
8
作者 刘长安 马力文 +3 位作者 张淑兰 徐翠华 尚兵 刘英 《中国工业医学杂志》 CAS 北大核心 2004年第5期319-320,共2页
依据国家标准GB/T1614 5— 1995测定 2例铥 170内污染人员粪便中铥 170的放射性活度 ,并参照GB/T1614 8—1995进行摄入量、待积有效剂量E(5 0 )及 3年内累积有效剂量当量 (H3 ,E)的估算。 2例铥 170内污染人员的摄入量分别为(9 2 2&#... 依据国家标准GB/T1614 5— 1995测定 2例铥 170内污染人员粪便中铥 170的放射性活度 ,并参照GB/T1614 8—1995进行摄入量、待积有效剂量E(5 0 )及 3年内累积有效剂量当量 (H3 ,E)的估算。 2例铥 170内污染人员的摄入量分别为(9 2 2± 1 40 )× 10 5Bq和 (1 3 7± 0 2 1)× 10 5Bq ,E(5 0 )分别为 (6 15± 0 93 )× 10 -3 Sv和 (9 13± 1 40 )× 10 -4Sv ,H3 ,E分别为(6 11± 0 92 )× 10 -3 Sv和 (9 0 7± 1 40 )× 10 -4Sv。本事故中 2名工作人员铥 170摄入量低于相应的年摄入量限值 ,E(5 0 )低于 0 0 2Sv ,所造成的内污染和内照射均是轻微的 ,不需要采取加速排出体内铥 170的医学干预措施。 展开更多
关键词 铥-170 内污染 摄入量 待积有效剂量 累积有效剂量当量
下载PDF
Propagation delay and power dissipation for different aspect ratio of single-walled carbon nanotube bundled TSV
9
作者 Tanu Goyal Manoj Kumar Majumder Brajesh Kumar Kaushik 《Journal of Semiconductors》 EI CAS CSCD 2015年第6期99-104,共6页
Through-silicon vias (TSVs) have provided an attractive solution for three-dimensional (3D) integrated devices and circuit technologies with reduced parasitic losses and power dissipation, higher input-output (I/... Through-silicon vias (TSVs) have provided an attractive solution for three-dimensional (3D) integrated devices and circuit technologies with reduced parasitic losses and power dissipation, higher input-output (I/O) den- sity and improved system performance. This paper investigates the propagation delay and average power dissipation of single-walled carbon nanotube bundled TSVs having different via radius and height. Depending on the physical configuration, a comprehensive and accurate analytical model of CNT bundled TSV is employed to represent the via (vertical interconnect access) line of a driver-TSV-load (DTL) system. The via radius and height are used to estimate the bundle aspect ratio (AR) and the cross-sectional area. For a fixed via height, the delay and the power dissipation are reduced up to 96.2% using a SWCNT bundled TSV with AR = 300 : 1 in comparison to AR = 6:1. 展开更多
关键词 carbon nanotube through-silicon vias equivalent RLC circuit model propagation delay power-delay product area-delay product
原文传递
多级等速加载预压固结度简化计算方法的探讨
10
作者 施广焕 《中国市政工程》 2015年第2期86-89,124,共4页
规范中关于加载预压的多级等速加载计算,需要对每一级加载分别进行计算分析,计算参数较多,过程较为复杂。多级等速加载预压固结度简化计算采用等效面积法原理,将多级加载简化为一级等速加载,将平均固结度进行一级简化计算。对比分析表明... 规范中关于加载预压的多级等速加载计算,需要对每一级加载分别进行计算分析,计算参数较多,过程较为复杂。多级等速加载预压固结度简化计算采用等效面积法原理,将多级加载简化为一级等速加载,将平均固结度进行一级简化计算。对比分析表明:由简化计算方法得到的等速加载平均固结度计算值与规范算法结果较为接近,随着计算时间的增长,两者分析结果趋于一致,且简化计算方法参数较少、表达形式较为简单,适合于工程应用。 展开更多
关键词 多级等速 等效面积 加载预压 简化计算 一级简化
下载PDF
超声处理对原位颗粒增强铸造Al-Si-Cu复合材料组织的影响
11
作者 李娟 梁艳峰 +4 位作者 郭永春 杨忠 董晟全 赫国强 于阳 《材料热处理学报》 EI CAS CSCD 北大核心 2018年第7期15-20,共6页
采用接触反应法制备原位颗粒增强铸造Al-12Si-4Cu复合材料,研究超声处理工艺对原位TiC和TiAl_3颗粒形貌的影响。结果表明:在铸造Al-12Si-4Cu复合材料中可以原位生成团聚态TiC颗粒、长杆状或块状TiAl_3颗粒;未经超声处理时,TiC颗粒团聚... 采用接触反应法制备原位颗粒增强铸造Al-12Si-4Cu复合材料,研究超声处理工艺对原位TiC和TiAl_3颗粒形貌的影响。结果表明:在铸造Al-12Si-4Cu复合材料中可以原位生成团聚态TiC颗粒、长杆状或块状TiAl_3颗粒;未经超声处理时,TiC颗粒团聚等效直径约70μm,经1500 W超声处理后,其减小到45μm;当超声处理功率增大到3000 W,TiC的团聚现象消失,颗粒均匀分散在基体中,并且长杆状TiAl_3颗粒长度减小到50~150μm,块状TiAl_3颗粒转变为相互独立的小尺寸块状。 展开更多
关键词 铝基复合材料 超声处理 原位颗粒 团聚等效直径
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部