检索结果-南通市图书馆

Disturbance evolution and the nonlinear stability to the basic flows for two-dimensional quasi-geostrophic motion

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第13期44卷 1179-1184页

作者： SONG shiji and liu QinyuWeihai College , Harbin Institute of Technology , Weihai 264209, China Institute of Physical Oceanography , Ocean University of Qingdao , Qingdao 266003 , China Weihai College Harbin Institute of Technology Weihai China Institute of Physical Oceanography Ocean University of Qingdao Qingdao China

The status of disturbances of both initial values and parameters in the models is further investigated, the exact explicit estimates on the disturbance energy and disturbance potential enstrophy are given; and while the initial disturbance fields rely only on the initial disturbance potential enstrophy, initial disturbance velocity circulation along the boundary, disturbance parameters, and the nonlinear stability criteria paralleling to Arnold’s second theorem are obtained, and the main results of Mu are generalized.

关键词： two-dimensional quasi-geostrophic motion disturbances of both initial values and parameters stability.

在线全文

学校读者我要写书评

暂无评论

多作动器协同的特种车辆行车调平控制方法

兵工学报 2023年第1期44卷 98-107页

作者：张聪刘爽姜思远刘世纪燕山大学电气工程学院河北秦皇岛066004 河北省工业计算机控制工程重点实验室燕山大学河北秦皇岛066004

针对国防军事、应急救援等国计民生重要领域中特种车辆行车调平的需求,基于多智能体一致性协同控制相关理论,提出多作动器协同的行车调平方法。将整车垂向模型分解为由作动器驱动的带有相互耦合特性的多智能体悬架节点,建立悬架节点动... 详细信息

针对国防军事、应急救援等国计民生重要领域中特种车辆行车调平的需求,基于多智能体一致性协同控制相关理论,提出多作动器协同的行车调平方法。将整车垂向模型分解为由作动器驱动的带有相互耦合特性的多智能体悬架节点,建立悬架节点动力学模型。构建基于悬架动行程的趋势引导动态基准和基准误差,摆脱现有调平方法对车身质心铅垂高的依赖,提出基于动态基准误差的多作动器协同行车调平方法。基于汽车系统仿真软件Carsim验证所提方法的有效性。研究结果表明,与整车型调平方法对比,所提方法更好地实现行车调平,调平精度提高了1到2个数量级;研究结果有助于进一步丰富和完善主动悬架控制技术体系,为解决特种车辆行车调平问题提供了全新思路和具体方法。

关键词：特种装备车辆行车调平主动悬架多作动器协同控制

维普期刊数据库博看期刊

A Dynamic Collaborative Planning Method for Multiminiaturized Vehicles

在线全文

学校读者我要写书评

暂无评论

A Dynamic Collaborative Planning Method for Multiminiaturize...

Dynamic Path Planning for Formula Automous Racing Cars

2021中国汽车工程学会年会暨展览会

作者： liu Yanbo Sun Weiqi Du Haikuo Xu Wenchao Xiong Xin Hao Li Qu Ling liu shiji Teaching development and Student Innovation Center of SEIEE Shanghai Jiao Tong University Department of automation Shanghai Jiao Tong University Shanghai Key Laboratory of Multidimensional Information Processing East China Normal University Huawei Cloud Huawei Technology Company Ltd Asset Management and Laboratories Division Shanghai Jiao Tong University Student Innovation Center Shanghai Jiao Tong University Michigan Colleger Shanghai Jiao Tong University

This paper takes the scheduling of multiple low-speed vehicles at multiple intersections as the main research content,studies the vehicle scheduling and motion control from the perspective of vehicle motion planning,and provides experimental verification based on the miniature vehicle experimental *** the formation scheduling,the leader vehicle of the formation plans the forward trajectory,and the follower vehicle plans the trajectory through the consistency method to realize the synchronization of the vehicles within the *** in the same lane that are relatively close together form a team,and often pass through multiple intersections for coordinated intersection *** the experimental part,this article will build miniature vehicles and intersection scenes to test the effectiveness of the algorithm in this article for scheduling and control in miniature scenes.

关键词： Multi-vehicle scheduling Path planning Vehicle-to-road communication Intersection collaboration

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

Dynamic Path Planning for Formula Automous Racing Cars

Prescribed-time Bipartite Formation Tracking Control of Heterogeneous Networked Agent Systems Over Signed Graph

第40届中国控制会议

作者： Yanbo liu Weiqi Sun shiji liu Wenchao Xu Xin Xiong Li Hao Fangjie Hu Ling Qu Teaching development and Student Innovation Center of SEIEE Shanghai Jiao Tong University Michigan Colleger Shanghai Jiao Tong University Shanghai Key Laboratory of Multidimensional Information Processing East China Normal University Huawei Cloud Huawei Technology Company Ltd Asset Management and Laboratories Division Shanghai Jiao Tong University Student Innovation Center Shanghai Jiaotong Univeristy

This paper proposes a Multi-fusion path following controller that aims to controlling the autonomous ground vehicle to the handling and driving limits,which is demonstrated by an autonomous *** a worldwide competition for autonomous racecar,the Formula Student Autonomous Competition（FSAC） is *** planning and control logic is the research focus of driverless formula racing and the key to improve lap *** on the design parameters of college students’ formula racing car,the vehicle kinematics and dynamics models were *** planning was accomplished using the Module Predictive Control（MPC） method based on the track data collected by the ***,the proposed controller is demonstrated on the self-developed autonomous *** experimental results on a random racetrack are discussed to show the efficiency of the proposed controller.

关键词： Autonomous vehicle FSAC Path planning Drive-by-wire chassis

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

Prescribed-time Bipartite Formation Tracking Control of Hete...

分泌性中耳炎诊断中应用声导抗检查临床价值分析

第35届中国过程控制会议

作者： Haoyang Yuan Boxian Lin shiji Tong Mengji Shi Kaiyu Qin Qiang liu School of Aeronautics and Astronautics University of Electronic Science and Technology of China Aircraft Swarm Intelligent Sensing and Cooperative Control Key Laboratory of Sichuan Province National Laboratory on Adaptive Optics

This paper addresses the bipartite formation tracking control problem of heterogeneous networked agent *** interactions among agents are described by a signed graph,where cooperation and competition coexist. Theoretically, a prescribed-time control scheme is designed for follower agents to achieve bipartite formation tracking. At first, the output regulation equation is employed to establish a mapping between state and output. Subsequently, we model the issue as an error stabilization problem, which facilitates the design of the controller. Secondly, by generating the time-scaling function, a prescribed-time formation tracking controller is designed. Then,the stability of the closed-loop system is proven by utilizing the Lyapunov theorem. Finally, the effectiveness of the proposed prescribed-time bipartite formation tracking controller is verified by some simulation results.

关键词： Bipartite formation Prescribed-time Heterogeneous networked agent systems Signed graph

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

中国社区医师 2018年第1期34卷 110-111页

作者：刘世吉兰州石化总医院耳鼻咽喉头颈外科 730060

目的:探讨声导抗检查在分泌性中耳炎诊断中的价值。方法:收治分泌性中耳炎患儿90例作为观察组,选择健康儿童90例作为对照组。均接受声导抗测试,比较两组检查结果。结果:观察组A型、As型、Ad型、B型、C型与对照组相比,差异有统计学意义(P... 详细信息

目的:探讨声导抗检查在分泌性中耳炎诊断中的价值。方法:收治分泌性中耳炎患儿90例作为观察组,选择健康儿童90例作为对照组。均接受声导抗测试,比较两组检查结果。结果:观察组A型、As型、Ad型、B型、C型与对照组相比,差异有统计学意义(P<0.05);观察组A型、As型、Ad型、B型、C型的声反射阳性率与对照组相比,差异有统计学意义(P<0.05);观察组纯音听阈测试中,平均PTA为34.1 d BHL,传导性聋76例(84.44%),混合性聋6例(6.67%),听力正常8例(8.89%)。结论:声导抗检查在分泌性中耳炎诊断中的价值较好,结合鼓压图、声反射、纯音听阈测试等能提高诊断率,减少误诊和漏诊。

关键词：分泌性中耳炎声导抗检查临床价值

Frequency Regulation of VSC-MTDC System with Offshore Wind Farms

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 275-286页

作者： Haoyu liu Chongru liu North China Electric Power University Beijing 102206China

Frequency regulation of voltage source converter-based multi-terminal high-voltage direct current(VSC-MTDC)system with offshore wind farms enhances the frequency stability by compensating the power for a disturbed AC ***,it is difficult to reasonably allocate frequency-regulation resources due to a lack of coordination mechanisms between wind farms and the MTDC ***,it is difficult for the frequency control of the wind farms to manage changes in wind speed;and the risk of wind-turbine stalls is ***,based on the kinetic energy of wind turbines and the power margin of the converters,the frequency-regulation capability of wind turbines is evaluated,and a dynamic frequency-support scheme considering the real-time frequency-support capability of the wind turbines and system frequency evolution is proposed to improve the frequency-support performance.A power adaptation technique at variable wind speeds is developed;the active power in the frequency-support stage and restoration stage is switched according to the wind speed.A hierarchical zoning frequency-regulation scheme is designed to use the frequency-regulation resources of different links in the MTDC system with wind *** simulation results show that the novel frequency-regulation strategy maintains frequency stability with wind-speed changes and avoids multiple frequency dips.

关键词： Wind generation voltage source converter-based multi-terminal high-voltage direct current(VSC-MTDC) frequency regulation cooperative control adaptive control variable wind speed

制造业服务化对企业投资效率的影响——基于组织效能视角的研究

在线全文

学校读者我要写书评

暂无评论

技术经济 2024年第6期43卷 110-124页

作者：刘亭立云世纪北京工业大学经济与管理学院北京100124

“发展服务型制造新模式,推动制造业高质量发展”是党中央、国务院做出的重要部署。以2011—2021年中国制造业上市公司为研究样本,实证检验了制造业服务化对企业投资效率的影响。研究发现,制造业服务化能够显著提高企业投资效率,主要的... 详细信息

“发展服务型制造新模式,推动制造业高质量发展”是党中央、国务院做出的重要部署。以2011—2021年中国制造业上市公司为研究样本,实证检验了制造业服务化对企业投资效率的影响。研究发现,制造业服务化能够显著提高企业投资效率,主要的机制在于服务化有助于公司组织效能的提升,缓解了过度投资,提高了投资效率。减少组织冗余和提高资产管理效率是提高投资效率的重要路径。公司治理水平高的企业以及处于关系国家安全和国民经济命脉的重要行业和关键领域的企业,服务化对投资效率的促进效应更加显著。本文研究为制造业服务化转型的微观经济效应提供了新的经验证据和理论解释,有利于促进制造企业进一步挖掘服务化的价值潜力,推动我国制造业服务化转型升级实现高质量发展。

关键词：制造业服务化投资效率服务型制造资源配置

A Novel Design of a Pre-separation Panel Structure to Protect Against the Impact of an Explosion in an Aircraft Plenum Chamber

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第1期37卷 166-180页

作者： Zongxing liu Xiang Yang Jun liu School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China COMAC Shanghai Aircraft Design and Research Institute Shanghai 201210China

To reduce the damage of the pressurizing panel structure of a fuselage caused by an explosion at the“least risk bomb location”in an aircraft structure,a new pre-separation panel structure was designed to resist blast ***,the dynamic strain response and morphology of impact damage of the new pre-separation panel were measured in an impact damage ***,the commercial software LS-DYNA was used to calculate the propagation of the blast shock wave,and the results were compared with empirical equations to verify the rationality of the numerical calculation ***,the fluid–structure coupling method was used to calculate the damage process of the pre-separation panel structure under the impact of an explosion wave and an impact *** calculated results were in good agreement with the test results,which showed the rationality of the calculation method and the *** residual strength of the damaged pre-separation panel was significantly higher than that of the original damaged *** results show that the new pre-separation panel structure is reasonable and has certain significance for guiding the design of plenum chambers with strong resistance to implosion for aircraft fuselages.

关键词： Pre-separation panel structure Explosive response Residual strength Aircraft plenum chamber Least risk bomb location