The eradication of poliomyelitis is a landmark achievement in the history of public health, providing strong protection for children’s health. The introduction of the Chinese Regulations for the Manufacture and Contr...The eradication of poliomyelitis is a landmark achievement in the history of public health, providing strong protection for children’s health. The introduction of the Chinese Regulations for the Manufacture and Control of Live Poliovirus Vaccine is a prerequisite and safeguard for the large-scale production and use of domestically produced live poliovirus vaccines, serving as an indispensable component of vaccine safety. This article, based on archival documents, letters, collections of essays, and oral interviews, examines the historical experience of the development of Chinese Regulations for the Manufacture and Control of Live Poliovirus Vaccine. It contends that the emphasis on localization and the active engagement in international cooperation are critical factors in the swift introduction of Chinese Regulations for the Manufacture and Control of Live Poliovirus Vaccine.展开更多
This paper investigates the cooperative adaptive optimal output regulation problem of continuous-time linear multi-agent systems.As the multi-agent system dynamics are uncertain,solving regulator equations and the cor...This paper investigates the cooperative adaptive optimal output regulation problem of continuous-time linear multi-agent systems.As the multi-agent system dynamics are uncertain,solving regulator equations and the corresponding algebraic Riccati equations is challenging,especially for high-order systems.In this paper,a novel method is proposed to approximate the solution of regulator equations,i.e.,gradient descent method.It is worth noting that this method obtains gradients through online data rather than model information.A data-driven distributed adaptive suboptimal controller is developed by adaptive dynamic programming,so that each follower can achieve asymptotic tracking and disturbance rejection.Finally,the effectiveness of the proposed control method is validated by simulations.展开更多
This paper investigates the cooperative output regulation problem of heterogeneous linear multi-agent systems over directed graphs with the constraint of communication bandwidth.Given that there exists an exosystem wh...This paper investigates the cooperative output regulation problem of heterogeneous linear multi-agent systems over directed graphs with the constraint of communication bandwidth.Given that there exists an exosystem whose state information is not available to all agents,the authors develop distributed adaptive event-triggered observers for the followers based on relative information between neighboring agents.It should be pointed out that,two kinds of time-varying gains are introduced to avoid relying on any global information associated with the network,and dynamic triggering conditions are designed to get rid of continuous communications.On the basis of the designed observers,the authors devise a local controller for each agent.Compared with the existing related works,the main contribution of the current paper is that the cooperative output regulation problem for general directed graphs is solved requiring neither global information nor continuous communications.展开更多
针对室内场景图像语义分割结果不精确、显著图粗糙的问题,提出一种基于多模态特征优化提取和双路径引导解码的网络架构(feature regulator and dual-path guidance,FG-Net)。具体来说,设计的特征调节器对每个阶段的多模态特征依次进行...针对室内场景图像语义分割结果不精确、显著图粗糙的问题,提出一种基于多模态特征优化提取和双路径引导解码的网络架构(feature regulator and dual-path guidance,FG-Net)。具体来说,设计的特征调节器对每个阶段的多模态特征依次进行噪声过滤、重加权表示、差异性互补和交互融合,通过强化RGB和深度特征聚合,优化特征提取过程中的多模态特征表示。然后,在解码阶段引入特征交互融合后丰富的跨模态线索,进一步发挥多模态特征的优势。结合双路径协同引导结构,在解码阶段融合多尺度、多层次的特征信息,从而输出更细致的显著图。实验在公开数据集NYUD-v2和SUN RGB-D上进行,在主要评价指标mIoU上达到48.5%,优于其他先进算法。结果表明,该算法实现了更精细的室内场景图像语义分割,表现出了较好的泛化性和鲁棒性。展开更多
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 ...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 system.However,it is difficult to reasonably allocate frequency-regulation resources due to a lack of coordination mechanisms between wind farms and the MTDC system.Moreover,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 high.Thus,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 farms.The simulation results show that the novel frequency-regulation strategy maintains frequency stability with wind-speed changes and avoids multiple frequency dips.展开更多
新型配电网分布式电源(Distributed Generation,DG)引起的低压侧电压波动是影响用户电能质量的关键因素。文中针对新型配电网的电压调节问题,在电网无功充足的条件下,提出了一种基于有载调压变压器(On-load Tap Changer,OLTC)与模块化...新型配电网分布式电源(Distributed Generation,DG)引起的低压侧电压波动是影响用户电能质量的关键因素。文中针对新型配电网的电压调节问题,在电网无功充足的条件下,提出了一种基于有载调压变压器(On-load Tap Changer,OLTC)与模块化配电变压器(Modular Distribution Transformer,MDT)的分层逐级协同调压策略。该策略首先提出电压断面质量这一概念并给出不同情况的建模方法,然后将电压波动范围分为三个区间:区间1为正常区间、区间2为轻微越限区间、区间3为严重越限区间。考虑到经济性和MDT的快响应性,策略将MDT作为主要调节方式,OLTC作为后备调节手段。最后通过仿真对比不同策略下的调节效果,验证了所提策略的合理性。展开更多
基金This work was supported by a key project of the 14th Five Year Plan of the Institute for the History of Natural Sciences,Chinese Academy of Sciences(E2291J01)the Youth Promotion Association of the Chinese Academy of Sciences(E3292G02).
文摘The eradication of poliomyelitis is a landmark achievement in the history of public health, providing strong protection for children’s health. The introduction of the Chinese Regulations for the Manufacture and Control of Live Poliovirus Vaccine is a prerequisite and safeguard for the large-scale production and use of domestically produced live poliovirus vaccines, serving as an indispensable component of vaccine safety. This article, based on archival documents, letters, collections of essays, and oral interviews, examines the historical experience of the development of Chinese Regulations for the Manufacture and Control of Live Poliovirus Vaccine. It contends that the emphasis on localization and the active engagement in international cooperation are critical factors in the swift introduction of Chinese Regulations for the Manufacture and Control of Live Poliovirus Vaccine.
基金supported in part by the National Natural Science Foundation of China under Grant No.62373090the U.S.National Science Foundation under Grant No.CNS-2227153.
文摘This paper investigates the cooperative adaptive optimal output regulation problem of continuous-time linear multi-agent systems.As the multi-agent system dynamics are uncertain,solving regulator equations and the corresponding algebraic Riccati equations is challenging,especially for high-order systems.In this paper,a novel method is proposed to approximate the solution of regulator equations,i.e.,gradient descent method.It is worth noting that this method obtains gradients through online data rather than model information.A data-driven distributed adaptive suboptimal controller is developed by adaptive dynamic programming,so that each follower can achieve asymptotic tracking and disturbance rejection.Finally,the effectiveness of the proposed control method is validated by simulations.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.61973006 and 62103302Shanghai Sailing Program under Grant No. 21YF1450300+2 种基金Shanghai Municipal Science and Technology Major Project under Grant No. 2021SHZDZX0100Shanghai Municipal Commission of Science and Technology Project under Grant No. 19511132101the Fundamental Research Funds for the Central Universities under Grant No. 22120210523
文摘This paper investigates the cooperative output regulation problem of heterogeneous linear multi-agent systems over directed graphs with the constraint of communication bandwidth.Given that there exists an exosystem whose state information is not available to all agents,the authors develop distributed adaptive event-triggered observers for the followers based on relative information between neighboring agents.It should be pointed out that,two kinds of time-varying gains are introduced to avoid relying on any global information associated with the network,and dynamic triggering conditions are designed to get rid of continuous communications.On the basis of the designed observers,the authors devise a local controller for each agent.Compared with the existing related works,the main contribution of the current paper is that the cooperative output regulation problem for general directed graphs is solved requiring neither global information nor continuous communications.
基金supported by the National Key R&D Program of China(No.2022YFB2402700).
文摘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 system.However,it is difficult to reasonably allocate frequency-regulation resources due to a lack of coordination mechanisms between wind farms and the MTDC system.Moreover,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 high.Thus,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 farms.The simulation results show that the novel frequency-regulation strategy maintains frequency stability with wind-speed changes and avoids multiple frequency dips.
文摘新型配电网分布式电源(Distributed Generation,DG)引起的低压侧电压波动是影响用户电能质量的关键因素。文中针对新型配电网的电压调节问题,在电网无功充足的条件下,提出了一种基于有载调压变压器(On-load Tap Changer,OLTC)与模块化配电变压器(Modular Distribution Transformer,MDT)的分层逐级协同调压策略。该策略首先提出电压断面质量这一概念并给出不同情况的建模方法,然后将电压波动范围分为三个区间:区间1为正常区间、区间2为轻微越限区间、区间3为严重越限区间。考虑到经济性和MDT的快响应性,策略将MDT作为主要调节方式,OLTC作为后备调节手段。最后通过仿真对比不同策略下的调节效果,验证了所提策略的合理性。