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电子商务系统信任模型动态控制方案的研究 被引量:2
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作者 杨建喜 葛垚 《微机发展》 2005年第12期157-159,163,共4页
在电子商务系统中,选择正确的信任模型以及其它相应的安全级别是非常重要的。为了对信任模型中的信任关系进行更好的管理,需要采用一定的方法对信任模型中的信任关系进行控制。为此,文中在传统的基于X.509证书标准的静态控制方案上做了... 在电子商务系统中,选择正确的信任模型以及其它相应的安全级别是非常重要的。为了对信任模型中的信任关系进行更好的管理,需要采用一定的方法对信任模型中的信任关系进行控制。为此,文中在传统的基于X.509证书标准的静态控制方案上做了一定的改进,提出了一种更加灵活的信任模型动态控制方案。在该控制方案中,引入了信任信息提供者这一新的成员,还对该控制方案的工作过程做了详细描述。这种动态控制方案更能适应电子商务系统发展的趋势。 展开更多
关键词 电子商务 信任模型 动态控制方案 证书 认证中心
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燕山水库汛限水位动态控制方案研究 被引量:1
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作者 褚青来 马福恒 叶伟 《水利水运工程学报》 CSCD 北大核心 2017年第1期43-48,共6页
随着全球极端气候越发频繁、水资源时空分布更加不均,水资源供需矛盾日益加剧。为充分利用水库调控水资源能力和发挥工程效益,采用预蓄预泄法对燕山水库汛限水位进行动态控制方案研究,首先基于下游防洪安全,根据降雨与洪水预报信息,采... 随着全球极端气候越发频繁、水资源时空分布更加不均,水资源供需矛盾日益加剧。为充分利用水库调控水资源能力和发挥工程效益,采用预蓄预泄法对燕山水库汛限水位进行动态控制方案研究,首先基于下游防洪安全,根据降雨与洪水预报信息,采取预蓄预泄方案确定汛限水位上限值;再基于大坝自身安全和水库超泄能力分析确定了主汛期与后汛期的最高汛限水位。与原汛限水位104.20 m相比,考虑洪水预报信息情况汛限水位可调整至104.77 m,考虑降雨预报信息时可调整至105.36 m。计算分析结果表明,调整后的动态汛限水位对大坝自身安全及下游防洪安全影响较小,提高了水资源可利用率,具有可实施性。 展开更多
关键词 燕山水库 汛限水位 动态控制方案 预蓄预泄
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基于WLAN与WCDMA融合网络的动态带宽控制方案
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作者 陈琦 《软件》 2012年第12期272-276,共5页
以实现WLAN用户差异化带宽服务为目的,提出了一整套较为完善的WLAN用户带宽的动态控制方案,该方案主要由四个模块组成:用户信息获取模块、用户评分模块、用户权重计算模块和队列调度控制模块。最后通过MATLAB搭建了多队列系统,仿真结果... 以实现WLAN用户差异化带宽服务为目的,提出了一整套较为完善的WLAN用户带宽的动态控制方案,该方案主要由四个模块组成:用户信息获取模块、用户评分模块、用户权重计算模块和队列调度控制模块。最后通过MATLAB搭建了多队列系统,仿真结果表明,基于动态控制方案的排队系统不仅能为用户提供了良好的差异化服务,而且相比现有的无动态控制排队系统,在整体性能上也有所提升。 展开更多
关键词 无线通信技术 动态控制方案 模糊数学 排队论 融合网络
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The Design and Control of Distillation Column with Side Reactors for Chlorobenzene Production 被引量:6
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作者 薄翠梅 汤吉海 +3 位作者 柏杨进 乔旭 丁良辉 张湜 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第6期1113-1120,共8页
The distillation column with side reactors (SRC) can overcome the temperature/pressure mismatch in the traditional reactive distillation, the column operates at temperature/pressure favorable for vapor-liquid separati... The distillation column with side reactors (SRC) can overcome the temperature/pressure mismatch in the traditional reactive distillation, the column operates at temperature/pressure favorable for vapor-liquid separation, while the reactors operate at temperatures/pressures favorable for reaction kinetics. According to the smooth operation and automatic control problem of the distillation column with side reactors (SRC), the design, simulation calculation and dynamic control of the SCR process for chlorobenzene production are discussed in the paper. Firstly, the mechanism models, the integrated structure optimal design and process simulation systems are established, respectively. And then multivariable control schemes are designed, the controllability of SRC process based on the optimal steady-state integrated structure is explored. The dynamic response performances of closed-loop system against several disturbances are discussed to verify the effectiveness of control schemes for the SRC process. The simulating results show that the control structure using conventional control strategies can effectively overcome feeding disturbances in a specific range. 展开更多
关键词 distillation column with side reactors (SRC) mechanism models multivariable control schemes simula- tion system chlorobenzene production
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Life Extending Control of Helicopter Based on Dynamic Inversion
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作者 刘晶 吴爱国 《Transactions of Tianjin University》 EI CAS 2014年第3期215-222,共8页
The purpose of using life extending control for Black Hawk UH-60 helicopter is to make a trade-off between the handling qualities and the service life of critical components. An increase in service life span results i... The purpose of using life extending control for Black Hawk UH-60 helicopter is to make a trade-off between the handling qualities and the service life of critical components. An increase in service life span results in enhanced safety and the reduction in maintenance costs. This paper presents a design methodology of life extending control for structural durability and high performance of mechanical system, which is based on an explicit dynamic inversion control scheme. A real-time nonlinear fatigue crack growth model is built to predict fatigue damage resulting from the impact of cyclic bending stress on rotor shaft, which serves as an indicator of service life. The 4-axis gainscheduled flight controller, whose gains are adjusted as a function of damage and flight velocity, is designed to regulate roll attitude, pitch attitude, vertical velocity and yaw rate. The nonlinear system simulation results show that the responses can meet the requirements on ADS-33 Level 1 handling qualities and that the 4-axis decoupling control is realized. As the damage increases, the tracking performance is slightly degraded, which results in smaller transients in bending moment response. 展开更多
关键词 helicopter control life extending control dynamic inversion fatigue damage
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L_1 adaptive controller design for hypersonic formation flight 被引量:5
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作者 CHEN Qi WAN Jing AI JianLiang 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第10期1597-1608,共12页
The design of an L_1 adaptive controller for hypersonic formation flight is presented. The traditional leader/wingman formation control problem is considered, with focused attention on dealing with the input disturban... The design of an L_1 adaptive controller for hypersonic formation flight is presented. The traditional leader/wingman formation control problem is considered, with focused attention on dealing with the input disturbance and parametric variations, both of which are intrinsic properties of the system that result in undesired control performance. A proportional-derivative control scheme based on nonlinear dynamic inversion is implemented as the baseline controller, and an L_1 adaptive controller is augmented to the baseline controller to attenuate the effects of input disturbance and parametric variations. Simulation results illustrate the effectiveness of the proposed control scheme. 展开更多
关键词 hypersonic flight control nonlinear dynamic inversion L1 adaptive control input disturbance parametric variation
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