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Controlling the dynamic behavior of decentralized cluster through centralized approaches
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作者 袁大明 王培龙 +6 位作者 王鹏 马星宇 汪楚云 王璟 陈怀城 王高 叶方富 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期46-54,共9页
How to control the dynamic behavior of large-scale artificial active matter is a critical concern in experimental research on soft matter, particularly regarding the emergence of collective behaviors and the formation... How to control the dynamic behavior of large-scale artificial active matter is a critical concern in experimental research on soft matter, particularly regarding the emergence of collective behaviors and the formation of group patterns. Centralized systems excel in precise control over individual behavior within a group, ensuring high accuracy and controllability in task execution. Nevertheless, their sensitivity to group size may limit their adaptability to diverse tasks. In contrast, decentralized systems empower individuals with autonomous decision-making, enhancing adaptability and system robustness. Yet, this flexibility comes at the cost of reduced accuracy and efficiency in task execution. In this work, we present a unique method for regulating the centralized dynamic behavior of self-organizing clusters based on environmental interactions. Within this environment-coupled robot system, each robot possesses similar dynamic characteristics, and their internal programs are entirely identical. However, their behaviors can be guided by the centralized control of the environment, facilitating the accomplishment of diverse cluster tasks. This approach aims to balance the accuracy and flexibility of centralized control with the robustness and task adaptability of decentralized control. The proactive regulation of dynamic behavioral characteristics in active matter groups, demonstrated in this work through environmental interactions, holds the potential to introduce a novel technological approach and provide experimental references for studying the dynamic behavior control of large-scale artificial active matter systems. 展开更多
关键词 self-organizing system centralized control dynamics regulation
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Contract Mechanism of Water Environment Regulation for Small and Medium Sized Enterprises Based on Optimal Control Theory
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作者 Shuang Zhao Hongbin Gu +2 位作者 Lianfang Xue Dongsheng Wang Bin Huang 《Journal of Water Resource and Protection》 CAS 2024年第7期538-556,共20页
The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of trea... The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of treatment. How enterprises can make reasonable decisions on their water environment behavior based on the external environment and their own factors is of great significance for scientifically and effectively designing water environment regulation mechanisms. Based on optimal control theory, this study investigates the design of contractual mechanisms for water environmental regulation for small and medium-sized enterprises. The enterprise is regarded as an independent economic entity that can adopt optimal control strategies to maximize its own interests. Based on the participation of multiple subjects including the government, enterprises, and the public, an optimal control strategy model for enterprises under contractual water environmental regulation is constructed using optimal control theory, and a method for calculating the amount of unit pollutant penalties is derived. The water pollutant treatment cost data of a paper company is selected to conduct empirical numerical analysis on the model. The results show that the increase in the probability of government regulation and public participation, as well as the decrease in local government protection for enterprises, can achieve the same regulatory effect while reducing the number of administrative penalties per unit. Finally, the implementation process of contractual water environmental regulation for small and medium-sized enterprises is designed. 展开更多
关键词 Optimal control Theory Small and Medium-Sized Enterprises Water Environment regulation Contract Mechanism
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Research on Regulating and Controlling Homogenization of Entertainment Programs--Based on Game Theory
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作者 Chen Mei Tian Shuge 《International English Education Research》 2014年第12期17-20,共4页
With the prevailing and popular entertainment programs, it brought huge benefits to TV stations, but at the same time caused a variety problems of homogenization. The paper analyzes the causes of the entertainment pro... With the prevailing and popular entertainment programs, it brought huge benefits to TV stations, but at the same time caused a variety problems of homogenization. The paper analyzes the causes of the entertainment programs, the root of homogenization, building game theory models between TV stations, TV station and audience to regulate and control the issue of homogeneity about entertainment programs. 展开更多
关键词 Entertainment Programs HOMOGENIZATION Game Theory Model regulate and control.
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Regulating and Controlling the Rising Prices of Geographical Indication Products in Inflation——taking Geographical Indication Products from Chongqing as an Example
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作者 吴茵 《海外英语》 2012年第21期285-288,共4页
Since July 2010,the prices of geographical indication products have risen with the occurrence of inflation.In contrast with other products,geographical indication products are distinct.The increasing prices of geograp... Since July 2010,the prices of geographical indication products have risen with the occurrence of inflation.In contrast with other products,geographical indication products are distinct.The increasing prices of geographical indication goods have their own necessities.From the perspective of the products,they are equipped with appreciation potential due to the cultural pe culiarities.From the historical standpoint,their prices have not been high as well as other agricultural products.Realistically,the increase in their prices results from the costs of labors and raw materials.Therefore,the prices of geographical indication products rise to catch up.Not only are their prices at a reasonable level,but also they are beneficial to increase peasants'income.In con clusion,it is necessary that the strategies which are different from those of other products be adopted to regulate and control the prices of geographical indication products. 展开更多
关键词 INFLATION GEOGRAPHICAL INDICATION PRODUCTS RISING
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Regulations for the Manufacture and Control of Live Poliovirus Vaccine: International Experience and China’s Path
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作者 Miao Wu 《Chinese Medical Sciences Journal》 CAS CSCD 2023年第4期315-320,共6页
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
关键词 Chinese regulations for the Manufacture and control of Live Poliovirus Vaccine international cooperation localization Gu Fang Zhou
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Gα_s signaling controls intramembranous ossification during cranial bone development by regulating both Hedgehog and Wnt/β-catenin signaling 被引量:7
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作者 Ruoshi Xu Sanjoy Kumar Khan +4 位作者 Taifeng Zhou Bo Gao Yaxing Zhou Xuedong Zhou Yingzi Yang 《Bone Research》 CAS CSCD 2018年第4期340-354,共15页
How osteoblast cells are induced is a central question for understanding skeletal formation. Abnormal osteoblast differentiation leads to a broad range of devastating craniofacial diseases. Here we have investigated i... How osteoblast cells are induced is a central question for understanding skeletal formation. Abnormal osteoblast differentiation leads to a broad range of devastating craniofacial diseases. Here we have investigated intramembranous ossification during cranial bone development in mouse models of skeletal genetic diseases that exhibit craniofacial bone defects. The GNAS gene encodes Gαs that transduces GPCR signaling. GNAS activation or loss-of-function mutations in humans cause fibrous dysplasia(FD) or progressive osseous heteroplasia(POH) that shows craniofacial hyperostosis or craniosynostosis, respectively. We find here that, while Hh ligand-dependent Hh signaling is essential for endochondral ossification, it is dispensable for intramembranous ossification, where Gαsregulates Hh signaling in a ligand-independent manner. We further show that Gαscontrols intramembranous ossification by regulating both Hh and Wnt/β-catenin signaling. In addition, Gαsactivation in the developing cranial bone leads to reduced ossification but increased cartilage presence due to reduced cartilage dissolution, not cell fate switch. Small molecule inhibitors of Hh and Wnt signaling can effectively ameliorate cranial bone phenotypes in mice caused by loss or gain of Gnas function mutations, respectively. Our work shows that studies of genetic diseases provide invaluable insights in both pathological bone defects and normal bone development, understanding both leads to better diagnosis and therapeutic treatment of bone diseases. 展开更多
关键词 s signaling controls intramembranous ossification during cranial bone development by regulating both Hedgehog and Wnt catenin signaling
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Self-Triggered Set Stabilization of Boolean Control Networks and Its Applications
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作者 Rong Zhao Jun-e Feng Dawei Zhang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第7期1631-1642,共12页
Set stabilization is one of the essential problems in engineering systems, and self-triggered control(STC) can save the storage space for interactive information, and can be successfully applied in networked control s... Set stabilization is one of the essential problems in engineering systems, and self-triggered control(STC) can save the storage space for interactive information, and can be successfully applied in networked control systems with limited communication resources. In this study, the set stabilization problem and STC design of Boolean control networks are investigated via the semi-tensor product technique. On the one hand, the largest control invariant subset is calculated in terms of the strongly connected components of the state transition graph, by which a graph-theoretical condition for set stabilization is derived. On the other hand, a characteristic function is exploited to determine the triggering mechanism and feasible controls. Based on this, the minimum-time and minimum-triggering open-loop, state-feedback and output-feedback STCs for set stabilization are designed,respectively. As classic applications of self-triggered set stabilization, self-triggered synchronization, self-triggered output tracking and self-triggered output regulation are discussed as well. Additionally, several practical examples are given to illustrate the effectiveness of theoretical results. 展开更多
关键词 Boolean control networks(BCNs) output regulation self-triggered control semi-tensor product of matrices set stabilization SYNCHRONIZATION
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Optimal Cooperative Secondary Control for Islanded DC Microgrids via a Fully Actuated Approach
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作者 Yi Yu Guo-Ping Liu +1 位作者 Yi Huang Peng Shi 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第2期405-417,共13页
DC-DC converter-based multi-bus DC microgrids(MGs) in series have received much attention, where the conflict between voltage recovery and current balancing has been a hot topic. The lack of models that accurately por... DC-DC converter-based multi-bus DC microgrids(MGs) in series have received much attention, where the conflict between voltage recovery and current balancing has been a hot topic. The lack of models that accurately portray the electrical characteristics of actual MGs while is controller design-friendly has kept the issue active. To this end, this paper establishes a large-signal model containing the comprehensive dynamical behavior of the DC MGs based on the theory of high-order fully actuated systems, and proposes distributed optimal control based on this. The proposed secondary control method can achieve the two goals of voltage recovery and current sharing for multi-bus DC MGs. Additionally, the simple structure of the proposed approach is similar to one based on droop control, which allows this control technique to be easily implemented in a variety of modern microgrids with different configurations. In contrast to existing studies, the process of controller design in this paper is closely tied to the actual dynamics of the MGs. It is a prominent feature that enables engineers to customize the performance metrics of the system. In addition, the analysis of the stability of the closed-loop DC microgrid system, as well as the optimality and consensus of current sharing are given. Finally, a scaled-down solar and battery-based microgrid prototype with maximum power point tracking controller is developed in the laboratory to experimentally test the efficacy of the proposed control method. 展开更多
关键词 DC microgrids distributed control high-order fully actuated system approach linear quadratic regulator microgrid modeling secondary control
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Adaptive Optimal Output Regulation of Interconnected Singularly Perturbed Systems With Application to Power Systems
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作者 Jianguo Zhao Chunyu Yang +2 位作者 Weinan Gao Linna Zhou Xiaomin Liu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第3期595-607,共13页
This article studies the adaptive optimal output regulation problem for a class of interconnected singularly perturbed systems(SPSs) with unknown dynamics based on reinforcement learning(RL).Taking into account the sl... This article studies the adaptive optimal output regulation problem for a class of interconnected singularly perturbed systems(SPSs) with unknown dynamics based on reinforcement learning(RL).Taking into account the slow and fast characteristics among system states,the interconnected SPS is decomposed into the slow time-scale dynamics and the fast timescale dynamics through singular perturbation theory.For the fast time-scale dynamics with interconnections,we devise a decentralized optimal control strategy by selecting appropriate weight matrices in the cost function.For the slow time-scale dynamics with unknown system parameters,an off-policy RL algorithm with convergence guarantee is given to learn the optimal control strategy in terms of measurement data.By combining the slow and fast controllers,we establish the composite decentralized adaptive optimal output regulator,and rigorously analyze the stability and optimality of the closed-loop system.The proposed decomposition design not only bypasses the numerical stiffness but also alleviates the high-dimensionality.The efficacy of the proposed methodology is validated by a load-frequency control application of a two-area power system. 展开更多
关键词 Adaptive optimal control decentralized control output regulation reinforcement learning(RL) singularly perturbed systems(SPSs)
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Event-triggered robust cooperative output regulation for a class of linear multi-agent systems with an unknown exosystem
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作者 Yangyang Qian Lu Liu 《Journal of Automation and Intelligence》 2024年第2期119-127,共9页
This paper investigates the robust cooperative output regulation problem for a class of heterogeneousuncertain linear multi-agent systems with an unknown exosystem via event-triggered control (ETC). By utilizingthe in... This paper investigates the robust cooperative output regulation problem for a class of heterogeneousuncertain linear multi-agent systems with an unknown exosystem via event-triggered control (ETC). By utilizingthe internal model approach and the adaptive control technique, a distributed adaptive internal model isconstructed for each agent. Then, based on this internal model, a fully distributed ETC strategy composed ofa distributed event-triggered adaptive output feedback control law and a distributed dynamic event-triggeringmechanism is proposed, in which each agent updates its control input at its own triggering time instants. It isshown that under the proposed ETC strategy, the robust cooperative output regulation problem can be solvedwithout requiring either the global information associated with the communication topology or the bounds ofthe uncertain or unknown parameters in each agent and the exosystem. A numerical example is provided toillustrate the effectiveness of the proposed control strategy. 展开更多
关键词 Adaptive control Event-triggered control Internal model Multi-agent systems Output regulation
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Predictive active control of building structures using LQR and artificial intelligence
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作者 Nirmal S.Mehta Vishisht Bhaiya +1 位作者 K.A.Patel Ehsan Noroozinejad Farsangi 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第2期489-502,共14页
This study presents a neural network-based model for predicting linear quadratic regulator(LQR)weighting matrices for achieving a target response reduction.Based on the expected weighting matrices,the LQR algorithm is... This study presents a neural network-based model for predicting linear quadratic regulator(LQR)weighting matrices for achieving a target response reduction.Based on the expected weighting matrices,the LQR algorithm is used to determine the various responses of the structure.The responses are determined by numerically analyzing the governing equation of motion using the state-space approach.For training a neural network,four input parameters are considered:the time history of the ground motion,the percentage reduction in lateral displacement,lateral velocity,and lateral acceleration,Output parameters are LQR weighting matrices.To study the effectiveness of an LQR-based neural network(LQRNN),the actual percentage reduction in the responses obtained from using LQRNN is compared with the target percentage reductions.Furthermore,to investigate the efficacy of an active control system using LQRNN,the controlled responses of a system are compared to the corresponding uncontrolled responses.The trained neural network effectively predicts weighting parameters that can provide a percentage reduction in displacement,velocity,and acceleration close to the target percentage reduction.Based on the simulation study,it can be concluded that significant response reductions are observed in the active-controlled system using LQRNN.Moreover,the LQRNN algorithm can replace conventional LQR control with the use of an active control system. 展开更多
关键词 active control system linear quadratic regulator artificial neural networks state-space approach response effectiveness factor RESILIENCE
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Motor Control Network Effective Connectivity in Regulating Muscle Force Output
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作者 Soha Saleh Zhiguo Jiang Guang H. Yue 《Natural Science》 2021年第2期9-17,共9页
Objective of the study: This study aimed at characterizing output features of the higher-order motor control centers (hoMCCs), including secondary (premotor cortex [Pre] and supplementary motor area [SMA]) and associa... Objective of the study: This study aimed at characterizing output features of the higher-order motor control centers (hoMCCs), including secondary (premotor cortex [Pre] and supplementary motor area [SMA]) and association (prefrontal cortex [PFC]) motor regions to the primary motor cortex (M1) during graded force tasks. It is well known that one of the major roles of the primary motor cortex (M1) is controlling motor output such as muscle force. However, it is unclear how the hoMCCs interact with M1 in regulating voluntary muscle contractions. Methods: fMRI data was acquired during graded force tasks and fMRI-based effective connectivity (EC) and muscle force analyses were performed to study the relationship between hoMCCs-M1 effective connectivity and voluntarily exerted handgrip force. Results: The results show that there is a consistent information flow from the hoMCCs to M1 under all force conditions, suggesting a hierarchical control mechanism in the brain in regulating voluntary muscle force. Only the premotor cortex exhibited a significant role in mediating the level of force production through its EC with M1 but that role diminished when the exerted force was high, suggesting perhaps a ceiling and/or fatigue effect on the EC. A flip in the direction of EC from the primary sensory cortex (S1) to the hoMCCs (PFC, SMA, and Pre) at lower force levels while at higher forces EC was observed from the hoMCCs to S1. Conclusion: The hoMCCs regulate M1 output to produce desired voluntary muscle force. Only the Pre-to-M1 connectivity strength directly correlates with the force level especially from low to moderate levels. The hoMCCs are involved in modulating higher force production likely by strengthening M1 output and downgrad<span style="font-size:12px;line-height:102%;font-family:Verdana;">ing</span><span style="font-size:12px;line-height:102%;font-family:Verdana;"> inhibition from S1 to M1.</span> 展开更多
关键词 Sensorimotor System Force regulation Effective Connectivity Motor control
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REGULATING THE IMPORT LICENSE CONTROL ON COMMODITIES
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《大经贸》 北大核心 1997年第6期94-94,共1页
Recently, Ministry of Foreign Trade and Economic Coop-eration issued a circular to the departments in charge of foreigntrade and economic cooperation under provinces, municipalitiesand autonomous regions, announcing t... Recently, Ministry of Foreign Trade and Economic Coop-eration issued a circular to the departments in charge of foreigntrade and economic cooperation under provinces, municipalitiesand autonomous regions, announcing that as of June 1, the Minis-try regulates its import license control on commodities and hasmade specific regulations.1. The import license control on agricultural chemical andcarbonate drink is removed and the control on "CD productionfacilities" is added. After the readjustment, totaling 35 commodi-ties are subject to import license control, and commodities undertariff lines are 374. Among them, 13 general commodities and 15mechanical and electrical commodities are subject to import quo-tas control; There are 7 commodities subject to import license butnon-quotas control.2. The import and export "CD production facilities" shall beconducted in accordance with the regulations as specified in 展开更多
关键词 regulating THE IMPORT LICENSE control ON COMMODITIES
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Technical Regulations for Comprehensive Control Weeding in Millet Field 被引量:1
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作者 周新建 刘环 +3 位作者 魏志敏 袁淑红 侯升林 周汉章 《Agricultural Science & Technology》 CAS 2016年第10期2321-2323,2426,共4页
According to experiments in many years in Hebei Province, the research explored weed comprehensive control technology on millet fields in terms of application range, prevention rules, prevention object, agricultural c... According to experiments in many years in Hebei Province, the research explored weed comprehensive control technology on millet fields in terms of application range, prevention rules, prevention object, agricultural control, physical control, and chemical control and proposed specific methods and technological indices in order to provide technological references for comprehensive control on weeds of millet fields. 展开更多
关键词 MILLET WEED Comprehensive control Technical regulations
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Control design for the nonlinear benchmark problem via the output regulation method 被引量:4
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作者 JieHUANG GuoqiangHU 《控制理论与应用(英文版)》 EI 2004年第1期11-19,共9页
The problem of designing a feedback controller to achieve asymptotic disturbance rejection / attenuation while maintaining good transient response in the RTAC system is known as a benchmark nonlinear control problem, ... The problem of designing a feedback controller to achieve asymptotic disturbance rejection / attenuation while maintaining good transient response in the RTAC system is known as a benchmark nonlinear control problem, which has been an intensive research subject since 1995. In this paper, we will further investigate the solvability of the robust disturbance rejection problem of the RTAC system by the measurement output feedback control based on the robust output regulation method. We have obtained a design by overcoming two major obstacles: find a closed-form solution of the regulator equations; and devise a nonlinear internal model to account for non-polynomial nonlinearities. 展开更多
关键词 RTAC system Robust control Nonlinear control Output regulation problem Disturbance rejection
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Asymptotic regulation of cascade systems with unknown control directions and nonlinear parameterization 被引量:4
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作者 Qiangde WANG Chunling WEI Yuqiang WU 《控制理论与应用(英文版)》 EI 2009年第1期51-56,共6页
A robust partial-state feedback asymptotic regulating control scheme is developed for a class of cascade systems with both nonlinear uncertainties and unknown control directions. A parameter separation technique is in... A robust partial-state feedback asymptotic regulating control scheme is developed for a class of cascade systems with both nonlinear uncertainties and unknown control directions. A parameter separation technique is introduced to separate the time-varying uncertainty and the unmeasurable state from nonlinear functions. Then, the Nussbaum-type gain method together with the idea of changing supply functions is adopted in the design of a smooth partial-state regulator that can ensure all the signals of the closed-loop system are globally uniformly bounded. Especially, the system state asymptotically converges to zero. The design procedure is illustrated through an example and the simulation results show that the controller is feasible and effective. 展开更多
关键词 Nonlinear systems Robust control Partial-state feedback Smooth regulator
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Notch signaling controls chondrocyte hypertrophy via indirect regulation of Sox9 被引量:9
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作者 Anat Kohn Timothy P Rutkowski +4 位作者 Zhaoyang Liu Anthony J Mirando Michael J Zuscik Regis J O'Keefe Matthew J Hilton 《Bone Research》 SCIE CAS CSCD 2015年第3期140-151,共12页
RBPjk-dependent Notch signaling regulates both the onset of chondrocyte hypertrophy and the progression to terminal chondrocyte maturation during endochondral ossification. It has been suggested that Notch signaling c... RBPjk-dependent Notch signaling regulates both the onset of chondrocyte hypertrophy and the progression to terminal chondrocyte maturation during endochondral ossification. It has been suggested that Notch signaling can regulate Sox9 transcription, although how this occurs at the molecular level in chondrocytes and whether this transcriptional regulation mediates Notch control of chondrocyte hypertrophy and cartilage development is unknown or controversial. Here we have provided conclusive genetic evidence linking RBPjk-dependent Notch signaling to the regulation of Sox9 expression and chondrocyte hypertrophy by examining tissuespecific Rbpjk mutant(Prx1Cre;Rbpjkf/f), Rbpjk mutant/Sox9 haploinsufficient(Prx1Cre;Rbpjkf/f;Sox9f/1),and control embryos for alterations in SOX9 expression and chondrocyte hypertrophy during cartilage development. These studies demonstrate that Notch signaling regulates the onset of chondrocyte maturation in a SOX9-dependent manner, while Notch-mediated regulation of terminal chondrocyte maturation likely functions independently of SOX9. Furthermore, our in vitro molecular analyses of the Sox9 promoter and Notch-mediated regulation of Sox9 gene expression in chondrogenic cells identified the ability of Notch to induce Sox9 expression directly in the acute setting, but suppresses Sox9 transcription with prolonged Notch signaling that requires protein synthesis of secondary effectors. 展开更多
关键词 Figure Notch signaling controls chondrocyte hypertrophy via indirect regulation of Sox9 NICD SOX
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Robust Non-fragile PID Controller Design for the Stroke Regulation of Metering Pumps 被引量:3
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作者 余世明 吴江江 张端 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第1期83-88,共6页
This job focuses on the stroke regulation of a class of high-precision metering pumps.A parametertuning method of robust non-fragile PID(proportional-integral-derivative)controllers is proposed with the assumption t... This job focuses on the stroke regulation of a class of high-precision metering pumps.A parametertuning method of robust non-fragile PID(proportional-integral-derivative)controllers is proposed with the assumption that a PID controller has additive gain perturbations.An H-infinite robust PID controller can be obtained by solving a linear matrix inequality.This approach can guarantee that the closed-loop control systems is asymptotically stable and the H-infinite norm of the transfer function from the disturbance to the output of a controlled system is less than a given constant to attenuate disturbances.The simulation case shows that the control performance of the proposed strategy is significantly better than the traditional PID approach in the situation with perturbations of controller parameters. 展开更多
关键词 metering pump stroke regulation H-infinite robust control PID control NON-FRAGILE
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Pressure Regulation for Earth Pressure Balance Control on Shield Tunneling Machine by Using Adaptive Robust Control 被引量:8
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作者 XIE Haibo LIU Zhibin YANG Huayong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第3期598-606,共9页
Most current studies about shield tunneling machine focus on the construction safety and tunnel structure stability during the excavation. Behaviors of the machine itself are also studied, like some tracking control o... Most current studies about shield tunneling machine focus on the construction safety and tunnel structure stability during the excavation. Behaviors of the machine itself are also studied, like some tracking control of the machine. Yet, few works concern about the hydraulic components, especially the pressure and flow rate regulation components. This research focuses on pressure control strategies by using proportional pressure relief valve, which is widely applied on typical shield tunneling machines. Modeling of a commercial pressure relief valve is done. The modeling centers on the main valve, because the dynamic performance is determined by the main valve. To validate such modeling, a frequency-experiment result of the pressure relief valve, whose bandwidth is about 3 Hz, is presented as comparison. The modeling and the frequency experimental result show that it is reasonable to regard the pressure relief valve as a second-order system with two low corner frequencies. PID control, dead band compensation control and adaptive robust control(ARC) are proposed and simulation results are presented. For the ARC, implements by using first order approximation and second order approximation are presented. The simulation results show that the second order approximation implement with ARC can track 4 Hz sine signal very well, and the two ARC simulation errors are within 0.2 MPa. Finally, experiment results of dead band compensation control and adaptive robust control are given. The results show that dead band compensation had about 30° phase lag and about 20% off of the amplitude attenuation. ARC is tracking with little phase lag and almost no amplitude attenuation. In this research, ARC has been tested on a pressure relief valve. It is able to improve the valve's dynamic performances greatly, and it is capable of the pressure control of shield machine excavation. 展开更多
关键词 shield tunneling machine pressure regulation adaptive robust control
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Flexural Property of String Beam of Pre-Stressed Glulam Based on Influence of Regulation and Control 被引量:2
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作者 Nan Guo Wenbo Wang Hongliang Zuo 《Structural Durability & Health Monitoring》 EI 2019年第2期143-179,共37页
Applying pre-stress in glulam beam can reduce its deformation and make full use of the compressive strength of wood.However,when the glulam with low strength and the pre-stressed steel with high strength form combined... Applying pre-stress in glulam beam can reduce its deformation and make full use of the compressive strength of wood.However,when the glulam with low strength and the pre-stressed steel with high strength form combined members,materials of high strength can’t be fully utilized.Therefore,this study puts forward the idea of regulating and controlling string beam of pre-stressed glulam.By regulating and controlling the pre-stress,a part of the load borne by the wood is allocated to the pre-stressed tendon,which is equivalent to completing a redistribution of internal force,thus realizing the repeated utilization of the wood strength and the full utilization of the strength of the high-strength pre-stressed tendon.The bending experiments of 10 beams under 5 working conditions are carried out.The failure mode,bearing capacity and deformation of the beams are analyzed.The results show that 90%of beams are deformed under compression.The ultimate load of the regulated and controlled beam is obviously larger than that of the unregulated beam,and the ultimate load of the beam increases with the increase of the degree of regulation and control.Compared with that of the unregulated beams,the ultimate load of beams regulated by 7.5%-30%increases by 25.42%-65.08%,and the regulated and controlled effect is obvious.With the increase of the regulation and control amplitude of pre-stress,the stiffness of string beam of pre-stressed glulam increases.In addition,with the increase of the regulation and control amplitude,the compression height of the beam increases before the failure,and it reaches the state of full-section compression at the time of failure,giving full play to the compressive property of the glulam.At the end of the experiment,the constitutive relation which can reflect the anisotropy of the wood is established combined with the experimental data.The finite element analysis of the beam under 7 working conditions is carried out by using ABAQUS finite element program,and the influence of the regulation and control amplitude on the stress distribution and ultimate bearing capacity of the beam is discussed. 展开更多
关键词 STRING beam of GLULAM FLEXURAL PROPERTY experimental study PRE-STRESS regulATION and control
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