检索结果-南通市图书馆

Decomposition of the Unsteady Wave Patterns for Bessho form Translating-Pulsating Source Green Function

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2014年第5期13卷 771-776页

作者： xiao wenbin DONG Wencai Department of Naval Architecture Naval University of Engineering

In order to interpret the physical feature of Bessho form translating-pulsating source Green function, the phase function is extracted from the integral representation and stationary-phase analysis is carried out in this paper. The complex characteristics of the integral variable and segmentation of the integral intervals are discussed in m complex plane. In θ space, the interval [-π/2+φ,-π/2+φ-iε] is dominant in the near-field flow, and there is a one-to-one correspondence between the real intervals in m space and the unsteady wave patterns in far field. If 4τ>1(τ is the Brard number), there are three kinds of propagation wave patterns such as ring-fan wave pattern, fan wave pattern and inner V wave pattern, and if 0<4τ<1, a ring wave pattern, an outer V and inner V wave pattern are presented in far field. The ring-fan or ring wave pattern corresponds to the interval [-π+α,-π/2+φ] for integral terms about k2, and the fan or outer V wave pattern and inner V wave pattern correspond to [-π+α,-π/2) and(-π/2,-π/2+φ] respectively for terms about k1. Numerical result shows that it is beneficial to decompose the unsteady wave patterns under the condition of τ≠0 by converting the integral variable θ to m. In addition, the constant-phase curve equations are derived when the source is performing only pulsating or translating.

关键词： translating-pulsating source unsteady wave patterns stationary-phase analysis near-field flow component wave component

Numerical Evaluation of Longitudinal Motions of Wigley Hulls Advancing in Waves by Using Bessho Form Translating-Pulsating Source Green's Function

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2016年第3期15卷 429-437页

作者： xiao wenbin DONG Wencai Academy of Ocean Science and Technology National University of Defense Technology Department of Naval Architecture Naval University of Engineering

In the framework of 3D potential flow theory, Bessho form translating-pulsating source Green's function in frequency domain is chosen as the integral kernel in this study and hybrid source-and-dipole distribution model of the boundary element method is applied to directly solve the velocity potential for advancing ship in regular waves. Numerical characteristics of the Green function show that the contribution of local-flow components to velocity potential is concentrated at the nearby source point area and the wave component dominates the magnitude of velocity potential in the far field. Two kinds of mathematical models, with or without local-flow components taken into account, are adopted to numerically calculate the longitudinal motions of Wigley hulls, which demonstrates the applicability of translating-pulsating source Green's function method for various ship forms. In addition, the mesh analysis of discrete surface is carried out from the perspective of ship-form characteristics. The study shows that the longitudinal motion results by the simplified model are somewhat greater than the experimental data in the resonant zone, and the model can be used as an effective tool to predict ship seakeeping properties. However, translating-pulsating source Green function method is only appropriate for the qualitative analysis of motion response in waves if the ship geometrical shape fails to satisfy the slender-body assumption.

关键词： translating-pulsating source local-flow component wave component longitudinal motions Wigley hulls surface mesh

Event-Triggered Adaptive Neural Control for Multiagent Systems with Deferred State Constraints

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2022年第3期35卷 973-992页

作者： YANG Bin CAO Liang xiao wenbin YAO Deyin LU Renquan School of Automation and Guangdong Province Key Laboratory of Intelligent Decision and Cooperative Control Guangdong University of TechnologyGuangzhou 510006China

This paper focuses on the leader-following consensus control problem for nonlinear multiagent systems subject to deferred asymmetric time-varying state constraints.A distributed eventtriggered adaptive neural control approach is *** virtue of a distributed sliding-mode estimator,the leader-following consensus control problem is converted into multiple simplified tracking control ***,a shifting function is utilized to transform the error variables such that the initial tracking condition can be totally unknown and the state constraints can be imposed at a specified time ***,the deferred asymmetric time-varying full state constraints are addressed by a class of asymmetric barrier Lyapunov *** order to reduce the burden of communication,a relative threshold event-triggered mechanism is incorporated into controller and Zeno behavior is *** on Lyapunov stability theorem,all closed-loop signals are proved to be semi-globally uniformly ultimately ***,a practical simulation example is given to verify the presented control scheme.

关键词： Adaptive neural control deferred time-varying state constraints event-triggered mechanism multiagent systems sliding-mode estimator

Clinical outcomes of primary rotating-hinge knee arthroplasty for knees with severe deformity

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2014年第9期127卷 1791-1793页

作者： Zhang Fujiang Liu Yabin xiao Yu Liu wenbin Department of Joint Reconstruction Tianjin Hospital Tianjin Medical University Tianjin 300210 China

Rotating-hinge total knee prostheses are often used for the treatment of global instability or severe bone loss around the knee,which is often accompanied by severe deformity.1 Competent and functional collateral ligaments are a prerequisite for performance of conventional total knee arthroplasty （TKA）.In cases of primary surgery for knees with severe deformities or in revision surgery for knees with substantial bone loss,standard condylar implants do not allow for proper stabilization of the *** these circumstances,condylar TKA designs will fail within a short period of time,or other complications such as anterior knee pain will occur soon after surgery.2

关键词： knee with severe deformity rotating-hinge knee

ESSA： An Efficient and Secure Splitting Algorithm for Distributed Storage Systems

在线全文

学校读者我要写书评

暂无评论

China Communications 2010年第4期7卷 89-95页

作者： CHEN Zhao YAO wenbin xiao Da WU Chunhua LIU Jianyi WANG Cong National Engineering Laboratory for Disaster Backup and Recovery Beijing University of Posts and Telecommunications Beijing 100876 China

The security of critical data is an important issue for distributed storage system design,especially for long-term *** (An Efficient and Secure Splitting Algorithm for Distributed Storage Systems) is presented,which takes advantage of a two level information dispersal scheme to strengthen the security of *** ESSA,the approach of knight’s tour problem,which is NP-Complete,is introduced to scramble data at the first level,and a split cube is used to split scrambled data at the second ***,it is very difficult for the malicious user to get information because the task of reconstructing the original data needs more computation than they can *** prove that the security of ESSA is better than encryption algorithm and not inferior to erasure codes and secret *** results show that distributed storage systems exploiting ESSA has greater efficiency than that exploiting keyed encryption,erasure codes and secret sharing.

关键词： Distributed System Secure Storage Information Dispersal knight's tour problem

在线全文

学校读者我要写书评

暂无评论

三维移动脉动源格林函数的对称性及其应用

国防科技大学学报 2015年第2期37卷 135-142页

作者：肖汶斌董文才海军工程大学舰船工程系湖北武汉430033

为进一步提高三维有航速船舶耐波性预报的计算效率,将对称性引入到移动脉动源格林函数法的速度势求解之中,提出了基于格林函数对称性的水动力快速求解措施。从源点对场点的对称特性出发,推导获得了调和函数的法向偏导数在船体对称线元... 详细信息

为进一步提高三维有航速船舶耐波性预报的计算效率,将对称性引入到移动脉动源格林函数法的速度势求解之中,提出了基于格林函数对称性的水动力快速求解措施。从源点对场点的对称特性出发,推导获得了调和函数的法向偏导数在船体对称线元和面元处的积分对称关系式,开展了对称性在简化边界元积分方程系数矩阵中的应用,进而构建了高效求解三维船舶耐波性能的理论计算方法。数值结果及算例分析表明:水动力计算中移动脉动源格林函数的对称性有利于降低计算量和减少系统内存,且适用于有航速船舶在波浪中的波浪干扰力、运动响应和自由面波形的数值模拟,可拓展至两船水动力干扰及复杂船型的频域水动力分析计算之中。

关键词：耐波性移动脉动源对称性格林函数法边界元积分

在线全文

学校读者我要写书评

暂无评论

信号交叉口流线实时消散的动态逻辑组合控制

信息与控制 2015年第6期44卷 745-752页

作者：刘伟肖文彬重庆交通大学交通运输学院重庆400074 武汉理工大学交通学院湖北武汉430063

在信号控制交叉口交通流线部分非饱和且车流到达波动较大情况下,定时或定相位感应控制不能最大化利用相位的绿灯时间.为实现信号控制与交通流线到达的波动性相适应,尽量减少周期绿灯损失,提高交叉口通行能力,提出交叉口流线动态组合控制... 详细信息

在信号控制交叉口交通流线部分非饱和且车流到达波动较大情况下,定时或定相位感应控制不能最大化利用相位的绿灯时间.为实现信号控制与交通流线到达的波动性相适应,尽量减少周期绿灯损失,提高交叉口通行能力,提出交叉口流线动态组合控制.由流线的交通特性以及逻辑函数确定交叉口可行控制相位组合,通过交叉口交通流线实时消散模型确定流线逻辑值,依据逻辑值的大小以及交叉口控制相位绿灯损失最少的逻辑组合原则,实现交叉口流线实时消散的动态逻辑组合控制.通过实例计算分析可知,随着交叉口流线车辆到达随时间显著性变化,流线动态逻辑组合控制比定周期或定相位的感应控制方式延误更小,控制方案更灵活,与交通流协调性更好,可提高交叉口时空资源利用效率.

关键词：交叉口信号控制实时消散模型逻辑组合相容流线逻辑值

Command-Filter-Based Adaptive Containment Control for Stochastic Nonlinear Multi-Agent Systems

在线全文

学校读者我要写书评

暂无评论

Command-Filter-Based Adaptive Containment Control for Stocha...

253.7 nm辐射源总辐射通量副基准的建立

第32届中国控制与决策会议

作者： wenbin xiao Hongyi Li Renquan Lu Wei Meng Yong Xu Guangdong Province Key Laboratory of Intelligent Decision and Cooperative Control Guangdong University of Technology

This paper studies the finite-time containment control problem for stochastic nonlinear multi-agent systems with unmeasurable *** the assumption that the communication topology is fixed and directed,a distributed neuro-adaptive containment scheme is proposed to drive all followers to converge into the convex hull spanned by the dynamic *** the control design,a second-order command filtered backstepping technique is adopted to deal with the explosion of complexity problem and the filtering error is compensated by an error compensation *** on stochastic stability theory,the stability of the nonlinear multi-agent system is verified via applying the proposed ***,the control property of the proposed strategy is validated by a numerical example.

关键词： Adaptive Containment Control Command Filtered Backstepping Stochastic Disturbances Multi-Agent Systems

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

计量学报 1999年第3期20卷 172-176页

作者：孙鼎文萧文宾中国计量科学研究院

简述了建立２５３．７ｎｍ辐射源总辐射通量副基准的原理和方法。提出了建立该副基准的关键问题并详细介绍了解决办法。

关键词：辐射源总辐射通量余弦响应误差副基准计量