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
BACKGROUND Post-hepatectomy liver failure(PHLF),represents a serious complication after liver resection,significantly impacting the long-term outcomes for patients who undergo such surgeries.There exists a strong corr...BACKGROUND Post-hepatectomy liver failure(PHLF),represents a serious complication after liver resection,significantly impacting the long-term outcomes for patients who undergo such surgeries.There exists a strong correlation between intraoperative hemorrhage and transfusion requirements with the development of PHLF.Presently,a combination of hepatic portal occlusion techniques alongside con-trolled low central venous pressure(CLCVP)methodologies is extensively em-ployed to mitigate intraoperative bleeding.Nonetheless,limited studies have analyzed the risk factors for PHLF under CLCVP.AIM To develop and validate a nomogram that predicts the risk factors associated with the development of PHLF patients undergoing liver resection with CLCVP.METHODS We conducted a retrospective analysis of 285 patients who underwent hepatectomy for the first time and had no history of prior non-index abdominal surgeries,with hepatic inflow occlusion combined with CLCVP from January to December 2019 in Hunan Provincial People’s Hospital.Univariate and multivariate regression analyses were used to identify preoperative and intraoperative risk factors for PHLF.Eligible patients were randomly divided into training and validation groups in a 7:3 ratio,and a nomogram prediction model was constructed.RESULTS The incidence of PHLF in these patients was 22.46%.Multiple logistic analysis showed that preoperative serum albumin level,causes of liver resection(cancer or others),and cirrhosis were independent preoperative risk factors for PHLF(P<0.05)and that only post-blocking blood potassium concentration was an independent intraoperative risk factor for PHLF(P<0.05).Least absolute shrinkage and selection operator regression analysis revealed that preoperative serum albumin level,direct bilirubin level(DBIL),platelet count,causes of liver resection(cancer or others),and cirrhosis were significant predictors of PHLF.The nomogram risk prediction model based on preoperative serum albumin level,DBIL,platelet count,causes of liver resection(cancer or others),cirrhosis and post-blocking blood potassium concentration can better predict the occurrence of PHLF.CONCLUSION For patients undergoing liver resection with CLCVP,serum albumin level,DBIL,platelet count,causes of liver resection(cancer or others),and cirrhosis are independent preoperative risk factors for PHLF.展开更多
This paper introduces the upgrading process and application effect of centralized control of water treatment system in 850 rolling line. At the beginning of the design, the water treatment system of Delong Iron and St...This paper introduces the upgrading process and application effect of centralized control of water treatment system in 850 rolling line. At the beginning of the design, the water treatment system of Delong Iron and Steel 850 rolling line was composed of four parts, including the primary tank system, laminar flow pump room system, central pump room system and high-pressure water system. The design was all operated by the machine side operation box. In order to meet the requirements of automatic operation, the whole water treatment system was upgraded and reformed in combination with NARI company. NARI PCS control system is used for centralized control. Through upgrading, all the control modes in the above areas are centralized to the control console, and unified centralized operation is carried out through PLC. This paper provides a reference for the upgrading of water treatment system and the design and application of control system in steel rolling plant.展开更多
We study afresh how the glucose control system anomalies impact the organicity of the glucose homeostasis and build up events of persistent hyperglycemia and diabetes mellitus. We have used critically the state of art...We study afresh how the glucose control system anomalies impact the organicity of the glucose homeostasis and build up events of persistent hyperglycemia and diabetes mellitus. We have used critically the state of art literature related to the subject, in order to cross, to compare, and to organize the relevant contents to create a logical and consistent support to the finds. We show that it is consistent to assume that persistent hyperglycemia and diabetes mellitus can have precursors not only in pancreas, but also in brain, mainly induced by noxious dysfunctions of hypothalamus sensor neurons circuits and external noxious elements, causing pancreas overload, and the consequent exhaustion—overburden.展开更多
Aiming at the existing problems of safety, reliability and flexibility in the traditional coal mine belt transport system, this paper designed the mine centralized control system transmitted by CAN bus and PLC as the ...Aiming at the existing problems of safety, reliability and flexibility in the traditional coal mine belt transport system, this paper designed the mine centralized control system transmitted by CAN bus and PLC as the core, and use comparison instructions and trigger of Siemens S7-200 PLC, the article has elaborated the four level conveyor belt sequence control, realized the sequence start, reverse sequence stop and fault processing and other functions for four level conveyor belt, the compared with traditional timer control instructions scheme, the design has clear thinking, simple design program, and is easy to be extended to multilevel belt drive sequence control.展开更多
Isolated operation of hydropower stations on Wujinag River was seen disadvantages of low rate of water utilization and much loss of electricity caused by abandoned water during low load periods. To tackle the problem,...Isolated operation of hydropower stations on Wujinag River was seen disadvantages of low rate of water utilization and much loss of electricity caused by abandoned water during low load periods. To tackle the problem, centralized control over cascade hydropower stations is practiced with a considerable economic benef it gained.展开更多
In recent years, with the rapid development of society, the demand for electric energy in the production field and life field is increasing, and the power supply quality is directly related to the performance of centr...In recent years, with the rapid development of society, the demand for electric energy in the production field and life field is increasing, and the power supply quality is directly related to the performance of centralized control operation steam turbine in power plant. Once there is an operation problem, it will lead to the reduction of smooth power supply, poor quality, and even affect the production and life of society, damage to the benefits of the power plant. Based on this, the author studies and discusses the centralized control operation of steam turbine, analyzes the existing shortcomings, and puts forward relevant operation optimization measures, in order to lay a solid foundation for improving the power generation quality and production efficiency of power plant.展开更多
One of the key tasks of centralized control operation of thermal power plant is to pre-control dangerous points, which ensures the safety of the whole thermal power plant. Therefore, it is necessary to understand the ...One of the key tasks of centralized control operation of thermal power plant is to pre-control dangerous points, which ensures the safety of the whole thermal power plant. Therefore, it is necessary to understand the main dangerous points and causes of centralized control operation, so as to take effective solutions, implementing preventive pre-control, and ensuring the safety of thermal power plant.展开更多
Under the background of rapid development of science and technology, people's quality of life continues to improve. In the actual life and production of modern people, there is almost no way to separate from the a...Under the background of rapid development of science and technology, people's quality of life continues to improve. In the actual life and production of modern people, there is almost no way to separate from the actual application of energy. Therefore, it is crucial to ensure normal and stable power generation. A normal power plant requires hard work from the staff. In the power plant, centralized control personnel are responsible for the normal production, delivery of facilities, design planning, inspection and maintenance. This paper will analyze and explain the training measures for the centralized control operation personnel of the newly-built power plant, hoping to provide some suggestions and ideas for the corresponding personnel.展开更多
The stable operation of thermal power plants is the core condition to ensure the stable power supply. Therefore, the application of unit centralized control technology around the three parts of the electromechanical f...The stable operation of thermal power plants is the core condition to ensure the stable power supply. Therefore, the application of unit centralized control technology around the three parts of the electromechanical furnace system layout, system principle, fixed value parameters, operation mode, logic and operation procedures control can improve the power generation stability of thermal power plants. Based on this, this paper first summarizes the concept of centralized control of thermal power plants and generating units, and then focuses on the principles and technical solutions of the application of centralized control technology of generating units.展开更多
Purpose-In order to solve the problem of inaccurate calculation of index weights,subjectivity and uncertainty of index assessment in the risk assessment process,this study aims to propose a scientific and reasonable c...Purpose-In order to solve the problem of inaccurate calculation of index weights,subjectivity and uncertainty of index assessment in the risk assessment process,this study aims to propose a scientific and reasonable centralized traffic control(CTC)system risk assessment method.Design/methodologylapproach-First,system-theoretic process analysis(STPA)is used to conduct risk analysis on the CTC system and constructs risk assessment indexes based on this analysis.Then,to enhance the accuracy of weight calculation,the fuzzy analytical hierarchy process(FAHP),fuzzy decision-making trial and evaluation laboratory(FDEMATEL)and entropy weight method are employed to calculate the subjective weight,relative weight and objective weight of each index.These three types of weights are combined using game theory to obtain the combined weight for each index.To reduce subjectivity and uncertainty in the assessment process,the backward cloud generator method is utilized to obtain the numerical character(NC)of the cloud model for each index.The NCs of the indexes are then weighted to derive the comprehensive cloud for risk assessment of the CTC system.This cloud model is used to obtain the CTC system's comprehensive risk assessment.The model's similarity measurement method gauges the likeness between the comprehensive risk assessment cloud and the risk standard cloud.Finally,this process yields the risk assessment results for the CTC system.Findings-The cloud model can handle the subjectivity and fuzziness in the risk assessment process well.The cloud model-based risk assessment method was applied to the CTC system risk assessment of a railway group and achieved good results.Originality/value-This study provides a cloud model-based method for risk assessment of CTC systems,which accurately calculates the weight of risk indexes and uses cloud models to reduce uncertainty and subjectivity in the assessment,achieving effective risk assessment of CTC systems.It can provide a reference and theoretical basis for risk management of the CTC system.展开更多
Software-Defined Networking(SDN)improves network management by separating its control logic from the underlying hardware and integrating it into a logically centralized control unit,termed the SDN controller.SDN adapt...Software-Defined Networking(SDN)improves network management by separating its control logic from the underlying hardware and integrating it into a logically centralized control unit,termed the SDN controller.SDN adaptation is essential for wireless networks because it offers enhanced and data-intensive services.The initial intent of the SDN design was to have a physically centralized controller.However,network experts have suggested logically centralized and physically distributed designs for SDN controllers,owing to issues such as a single point of failure and scalability.This study addressed the security,scalability,reliability,and consistency issues associated with the design of distributed SDN controllers.Moreover,the security issues of an enterprise related to multiple physically distributed controllers in a software-defined wireless local area network(SD-WLAN)were emphasized,and optimal solutions were suggested.展开更多
This paper explores the challenges of controlling complex metro systems,which are influenced by uncertain and uncontrollable large passenger flow impacts.Traditionally,flow-limiting measures during peak periods have b...This paper explores the challenges of controlling complex metro systems,which are influenced by uncertain and uncontrollable large passenger flow impacts.Traditionally,flow-limiting measures during peak periods have been based on experience rather than scientific theory.To bridge this gap,we introduce a novel network analysis method inspired by control centrality theory.This approach assesses the impact of traffic loads from single or multiple sources on any node within the metro network.Our method provides a scientific basis for operators to develop policies for managing overloaded traffic,enhancing both safety and efficiency in metro system operations.展开更多
Coordinated taxiing planning for multiple aircraft on flight deck is of vital importance which can dramatically improve the dispatching efficiency.In this paper,first,the coordinated taxiing path planning problem is t...Coordinated taxiing planning for multiple aircraft on flight deck is of vital importance which can dramatically improve the dispatching efficiency.In this paper,first,the coordinated taxiing path planning problem is transformed into a centralized optimal control problem where collision-free conditions and mechanical limits are considered.Since the formulated optimal control problem is of large state space and highly nonlinear,an efficient hierarchical initialization technique based on the Dubins-curve method is proposed.Then,a model predictive controller is designed to track the obtained reference trajectory in the presence of initial state error and external disturbances.Numerical experiments demonstrate that the proposed“offline planningþonline tracking”framework can achieve efficient and robust coordinated taxiing planning and tracking even in the presence of initial state error and continuous external disturbances.展开更多
As a typical rhythmic movement, human being＇s rhythmic gait movement can be generated by a central pattern generator （CPG） located in a spinal cord by self- oscillation. Some kinds of gait movements are caused by g...As a typical rhythmic movement, human being＇s rhythmic gait movement can be generated by a central pattern generator （CPG） located in a spinal cord by self- oscillation. Some kinds of gait movements are caused by gait frequency and amplitude variances. As an important property of human being＇s motion vision, the attention selection mechanism plays a vital part in the regulation of gait movement. In this paper, the CPG model is amended under the condition of attention selection on the theoretical basis of Matsuoka neural oscillators. Regulation of attention selection signal for the CPG model parameters and structure is studied, which consequentially causes the frequency and amplitude changes of gait movement output. Further, the control strategy of the CPG model gait movement under the condition of attention selection is discussed, showing that the attention selection model can regulate the output model of CPG gait movement in three different ways. The realization of regulation on the gait movement frequency and amplitude shows a variety of regulation on the CPG gait movement made by attention selection and enriches the controllability of CPG gait movement, which demonstrates potential influence in engineering applications.展开更多
With the explosive increasing number of connecting devices such as smart phones, vehicles,drones, and satellites in the wireless networks, how to manage and control such a huge number of networking nodes has become a ...With the explosive increasing number of connecting devices such as smart phones, vehicles,drones, and satellites in the wireless networks, how to manage and control such a huge number of networking nodes has become a great challenge. In this paper, we combine the advantages of centralized networks and distributed networks approaches for vehicular networks with the aid of Unmanned Aerial Vehicle(UAV), and propose a Center-controlled Multihop Wireless(CMW) networking scheme consisting of data transmission plane performed by vehicles and the network control plane implemented by the UAV.Besides, we jointly explore the advantages of Medium Access Control(MAC) protocols in the link layer and routing schemes in the network layer to facilitate the multi-hop data transmission for the ground vehicles.Particularly, the network control plane in the UAV can manage the whole network effectively via fully exploiting the acquired network topology information and traffic requests from each vehicle, and implements various kinds of control based on different traffic demands, which can enhance the networking flexibility and scalability significantly in vehicular networks.Simulation results validate the advantages of the proposed scheme compared with existing methods.展开更多
The influence of a node in a network can be characterized by its macroscopic properties such as eigenvector centrality. An issue of significant theoretical and practical interest is to modify the influence or roles of...The influence of a node in a network can be characterized by its macroscopic properties such as eigenvector centrality. An issue of significant theoretical and practical interest is to modify the influence or roles of the nodes in a network, and recent advances indicate that this can be achieved by just controlling a subset of nodes： the socalled controllers. However, the relationship between the structural properties of a network and its controllability, e.g., the control of node importance, is still not well understood. Here we systematically＂ explore this relationship by constructing scale-free networks with a fixed degree sequence and tunable network characteristics. We calculate the relative size （nc＊） of the minimai controlling set required to controi the importance of each individual node in a network. It is found that while clustering has no significant impact on nc＊, changes in degree-degree correlations, heterogeneity and the average degree of networks demonstrate a discernible impact on its controllability.展开更多
A microgrid(MG)refers to a set of loads,generation resources and energy storage systems acting as a controllable load or a generator to supply power and heating to a local area.The MG-generated power management is a c...A microgrid(MG)refers to a set of loads,generation resources and energy storage systems acting as a controllable load or a generator to supply power and heating to a local area.The MG-generated power management is a central topic for MG design and operation.The existence of dispersed generation(DG)resources has faced MG management with new issues.Depending on the level of exchanges between an MG and the main grid,the MG operation states can be divided into independent or grid-connected ones.Energy management in MGs aims to supply power at the lowest cost for optimal load response.This study examines MG energy management in two operational modes of islanded and grid-connected,and proposes a structure with two control layers(primary and secondary)for energy management.At the principal level of control,the energy management system is determined individually for all MG by taking into consideration the probability constraints and RES uncertainty by the Weibull the probability density function(PDF),generation resources’power as well as the generation surplus and deficit of each MG.Then,the information of the power surplus and deficit of each MG must be sent to the central energy management system.To confirm the proposed structure,a case system with two MGs and a condensive load is simulated by using a multi-time harmony search algorithm.Several scenarios are applied to evaluate the performance of this algorithm.The findings clearly show the effectiveness of the proposed system in the energy management of several MGs,leading to the optimal performance of the resources per MG.Moreover,the proposed control scheme properly controls the MG and grid’s performance in their interactions and offers a high level of robustness,stable behavior under different conditions and high quality of power supply.展开更多
With the rapid development of Chinas railway trains and heavy-haul railways, the construction scale of extra-long railway tunnels has been in the forefront of the world. This paper mainly discusses how to automaticall...With the rapid development of Chinas railway trains and heavy-haul railways, the construction scale of extra-long railway tunnels has been in the forefront of the world. This paper mainly discusses how to automatically identify the train state by ultrasonic ranging technology, and upload the train state information to the centralized control unit through PLC, so as to automatically control the lighting circuit in the tunnel to turn on or off, thus achieving the purposes of energy saving, low carbon and environmental protection, and prolonging the service life of equipment.展开更多
In view of the practical application of centralized traffic control(CTC)system of the Beijing-Shanghai HSR and in combination with the line conditions and user requirements,the system is optimized in terms of route se...In view of the practical application of centralized traffic control(CTC)system of the Beijing-Shanghai HSR and in combination with the line conditions and user requirements,the system is optimized in terms of route self-triggering polling frequency,train receiving route self-triggering timing,train departure route section processing,route self-triggering between yards,wireless route forecasting and automatic train number conversion,which improves the efficiency of automatic route setting of CTC system and the adaptability of high-density and long-major lines.At the same time,according to the intelligent development requirements of railways,the paper proposes the expectation for the centralized traffic control system of the Beijing-Shanghai HSR in terms of intelligent adjustment of TWD,information sharing with traction power supply supervisory control and data acquisition(SCADA)system/disaster monitoring system,intelligent linkage of posts,etc.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 12174041)China Postdoctoral Science Foundation (CPSF)(Grant No. 2022M723118)the seed grants from the Wenzhou Institute,University of Chinese Academy of Sciences (Grant No. WIUCASQD2021002)。
文摘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.
基金Supported by the Natural Science Foundation of Hunan Province,No.2018JJ3291the Scientific Research Project of the Hunan Provincial Health Commission,No.202104111288.
文摘BACKGROUND Post-hepatectomy liver failure(PHLF),represents a serious complication after liver resection,significantly impacting the long-term outcomes for patients who undergo such surgeries.There exists a strong correlation between intraoperative hemorrhage and transfusion requirements with the development of PHLF.Presently,a combination of hepatic portal occlusion techniques alongside con-trolled low central venous pressure(CLCVP)methodologies is extensively em-ployed to mitigate intraoperative bleeding.Nonetheless,limited studies have analyzed the risk factors for PHLF under CLCVP.AIM To develop and validate a nomogram that predicts the risk factors associated with the development of PHLF patients undergoing liver resection with CLCVP.METHODS We conducted a retrospective analysis of 285 patients who underwent hepatectomy for the first time and had no history of prior non-index abdominal surgeries,with hepatic inflow occlusion combined with CLCVP from January to December 2019 in Hunan Provincial People’s Hospital.Univariate and multivariate regression analyses were used to identify preoperative and intraoperative risk factors for PHLF.Eligible patients were randomly divided into training and validation groups in a 7:3 ratio,and a nomogram prediction model was constructed.RESULTS The incidence of PHLF in these patients was 22.46%.Multiple logistic analysis showed that preoperative serum albumin level,causes of liver resection(cancer or others),and cirrhosis were independent preoperative risk factors for PHLF(P<0.05)and that only post-blocking blood potassium concentration was an independent intraoperative risk factor for PHLF(P<0.05).Least absolute shrinkage and selection operator regression analysis revealed that preoperative serum albumin level,direct bilirubin level(DBIL),platelet count,causes of liver resection(cancer or others),and cirrhosis were significant predictors of PHLF.The nomogram risk prediction model based on preoperative serum albumin level,DBIL,platelet count,causes of liver resection(cancer or others),cirrhosis and post-blocking blood potassium concentration can better predict the occurrence of PHLF.CONCLUSION For patients undergoing liver resection with CLCVP,serum albumin level,DBIL,platelet count,causes of liver resection(cancer or others),and cirrhosis are independent preoperative risk factors for PHLF.
文摘This paper introduces the upgrading process and application effect of centralized control of water treatment system in 850 rolling line. At the beginning of the design, the water treatment system of Delong Iron and Steel 850 rolling line was composed of four parts, including the primary tank system, laminar flow pump room system, central pump room system and high-pressure water system. The design was all operated by the machine side operation box. In order to meet the requirements of automatic operation, the whole water treatment system was upgraded and reformed in combination with NARI company. NARI PCS control system is used for centralized control. Through upgrading, all the control modes in the above areas are centralized to the control console, and unified centralized operation is carried out through PLC. This paper provides a reference for the upgrading of water treatment system and the design and application of control system in steel rolling plant.
文摘We study afresh how the glucose control system anomalies impact the organicity of the glucose homeostasis and build up events of persistent hyperglycemia and diabetes mellitus. We have used critically the state of art literature related to the subject, in order to cross, to compare, and to organize the relevant contents to create a logical and consistent support to the finds. We show that it is consistent to assume that persistent hyperglycemia and diabetes mellitus can have precursors not only in pancreas, but also in brain, mainly induced by noxious dysfunctions of hypothalamus sensor neurons circuits and external noxious elements, causing pancreas overload, and the consequent exhaustion—overburden.
文摘Aiming at the existing problems of safety, reliability and flexibility in the traditional coal mine belt transport system, this paper designed the mine centralized control system transmitted by CAN bus and PLC as the core, and use comparison instructions and trigger of Siemens S7-200 PLC, the article has elaborated the four level conveyor belt sequence control, realized the sequence start, reverse sequence stop and fault processing and other functions for four level conveyor belt, the compared with traditional timer control instructions scheme, the design has clear thinking, simple design program, and is easy to be extended to multilevel belt drive sequence control.
文摘Isolated operation of hydropower stations on Wujinag River was seen disadvantages of low rate of water utilization and much loss of electricity caused by abandoned water during low load periods. To tackle the problem, centralized control over cascade hydropower stations is practiced with a considerable economic benef it gained.
文摘In recent years, with the rapid development of society, the demand for electric energy in the production field and life field is increasing, and the power supply quality is directly related to the performance of centralized control operation steam turbine in power plant. Once there is an operation problem, it will lead to the reduction of smooth power supply, poor quality, and even affect the production and life of society, damage to the benefits of the power plant. Based on this, the author studies and discusses the centralized control operation of steam turbine, analyzes the existing shortcomings, and puts forward relevant operation optimization measures, in order to lay a solid foundation for improving the power generation quality and production efficiency of power plant.
文摘One of the key tasks of centralized control operation of thermal power plant is to pre-control dangerous points, which ensures the safety of the whole thermal power plant. Therefore, it is necessary to understand the main dangerous points and causes of centralized control operation, so as to take effective solutions, implementing preventive pre-control, and ensuring the safety of thermal power plant.
文摘Under the background of rapid development of science and technology, people's quality of life continues to improve. In the actual life and production of modern people, there is almost no way to separate from the actual application of energy. Therefore, it is crucial to ensure normal and stable power generation. A normal power plant requires hard work from the staff. In the power plant, centralized control personnel are responsible for the normal production, delivery of facilities, design planning, inspection and maintenance. This paper will analyze and explain the training measures for the centralized control operation personnel of the newly-built power plant, hoping to provide some suggestions and ideas for the corresponding personnel.
文摘The stable operation of thermal power plants is the core condition to ensure the stable power supply. Therefore, the application of unit centralized control technology around the three parts of the electromechanical furnace system layout, system principle, fixed value parameters, operation mode, logic and operation procedures control can improve the power generation stability of thermal power plants. Based on this, this paper first summarizes the concept of centralized control of thermal power plants and generating units, and then focuses on the principles and technical solutions of the application of centralized control technology of generating units.
基金National Natural Science Foundation of China under Grant 62203468Technological Research and Development Program of China State Railway Group Co.,Ltd.under Grant J2023G007+2 种基金Young Elite Scientist Sponsorship Program by China Association for Science and Technology(CAST)under Grant 2022QNRC001Youth Talent Program Supported by China Railway SocietyResearch Program of Beijing Hua-Tie Information Technology Corporation Limited under Grant 2023HT02.
文摘Purpose-In order to solve the problem of inaccurate calculation of index weights,subjectivity and uncertainty of index assessment in the risk assessment process,this study aims to propose a scientific and reasonable centralized traffic control(CTC)system risk assessment method.Design/methodologylapproach-First,system-theoretic process analysis(STPA)is used to conduct risk analysis on the CTC system and constructs risk assessment indexes based on this analysis.Then,to enhance the accuracy of weight calculation,the fuzzy analytical hierarchy process(FAHP),fuzzy decision-making trial and evaluation laboratory(FDEMATEL)and entropy weight method are employed to calculate the subjective weight,relative weight and objective weight of each index.These three types of weights are combined using game theory to obtain the combined weight for each index.To reduce subjectivity and uncertainty in the assessment process,the backward cloud generator method is utilized to obtain the numerical character(NC)of the cloud model for each index.The NCs of the indexes are then weighted to derive the comprehensive cloud for risk assessment of the CTC system.This cloud model is used to obtain the CTC system's comprehensive risk assessment.The model's similarity measurement method gauges the likeness between the comprehensive risk assessment cloud and the risk standard cloud.Finally,this process yields the risk assessment results for the CTC system.Findings-The cloud model can handle the subjectivity and fuzziness in the risk assessment process well.The cloud model-based risk assessment method was applied to the CTC system risk assessment of a railway group and achieved good results.Originality/value-This study provides a cloud model-based method for risk assessment of CTC systems,which accurately calculates the weight of risk indexes and uses cloud models to reduce uncertainty and subjectivity in the assessment,achieving effective risk assessment of CTC systems.It can provide a reference and theoretical basis for risk management of the CTC system.
文摘Software-Defined Networking(SDN)improves network management by separating its control logic from the underlying hardware and integrating it into a logically centralized control unit,termed the SDN controller.SDN adaptation is essential for wireless networks because it offers enhanced and data-intensive services.The initial intent of the SDN design was to have a physically centralized controller.However,network experts have suggested logically centralized and physically distributed designs for SDN controllers,owing to issues such as a single point of failure and scalability.This study addressed the security,scalability,reliability,and consistency issues associated with the design of distributed SDN controllers.Moreover,the security issues of an enterprise related to multiple physically distributed controllers in a software-defined wireless local area network(SD-WLAN)were emphasized,and optimal solutions were suggested.
基金support for this paper by the National Key R&D Program of China(Grant No.2021YFC2600504)the National Natural Science Foundation of China(Grant No.72174104).
文摘This paper explores the challenges of controlling complex metro systems,which are influenced by uncertain and uncontrollable large passenger flow impacts.Traditionally,flow-limiting measures during peak periods have been based on experience rather than scientific theory.To bridge this gap,we introduce a novel network analysis method inspired by control centrality theory.This approach assesses the impact of traffic loads from single or multiple sources on any node within the metro network.Our method provides a scientific basis for operators to develop policies for managing overloaded traffic,enhancing both safety and efficiency in metro system operations.
文摘Coordinated taxiing planning for multiple aircraft on flight deck is of vital importance which can dramatically improve the dispatching efficiency.In this paper,first,the coordinated taxiing path planning problem is transformed into a centralized optimal control problem where collision-free conditions and mechanical limits are considered.Since the formulated optimal control problem is of large state space and highly nonlinear,an efficient hierarchical initialization technique based on the Dubins-curve method is proposed.Then,a model predictive controller is designed to track the obtained reference trajectory in the presence of initial state error and external disturbances.Numerical experiments demonstrate that the proposed“offline planningþonline tracking”framework can achieve efficient and robust coordinated taxiing planning and tracking even in the presence of initial state error and continuous external disturbances.
基金supported by the National Natural Science Foundation of China(Nos.11232005 and11472104)the Doctoral Fund of Ministry of Education of China(No.20120074110020)
文摘As a typical rhythmic movement, human being＇s rhythmic gait movement can be generated by a central pattern generator （CPG） located in a spinal cord by self- oscillation. Some kinds of gait movements are caused by gait frequency and amplitude variances. As an important property of human being＇s motion vision, the attention selection mechanism plays a vital part in the regulation of gait movement. In this paper, the CPG model is amended under the condition of attention selection on the theoretical basis of Matsuoka neural oscillators. Regulation of attention selection signal for the CPG model parameters and structure is studied, which consequentially causes the frequency and amplitude changes of gait movement output. Further, the control strategy of the CPG model gait movement under the condition of attention selection is discussed, showing that the attention selection model can regulate the output model of CPG gait movement in three different ways. The realization of regulation on the gait movement frequency and amplitude shows a variety of regulation on the CPG gait movement made by attention selection and enriches the controllability of CPG gait movement, which demonstrates potential influence in engineering applications.
基金supported in part by the National Natural Science Foundation of China under Grant 62071283,Grant 61771296,Grant 61872228 and Grant 62271513in part by the Natural Science Basic Research Plan in Shaanxi Province of China under Grant 2018JQ6048 and Grant 2018JZ6006+3 种基金in part by Shaanxi Key Industrial Innovation Chain Project in Industrial Domain under Grant 2020ZDLGY15-09in part by Guang Dong Basic and Applied Basic Research Foundation under Grant 2021A1515012631in part by China Postdoctoral Science Foundation under Grant 2016M600761in part by the Fundamental Research Funds for the Central Universities under Grant GK202003075 and Grant GK202103016。
文摘With the explosive increasing number of connecting devices such as smart phones, vehicles,drones, and satellites in the wireless networks, how to manage and control such a huge number of networking nodes has become a great challenge. In this paper, we combine the advantages of centralized networks and distributed networks approaches for vehicular networks with the aid of Unmanned Aerial Vehicle(UAV), and propose a Center-controlled Multihop Wireless(CMW) networking scheme consisting of data transmission plane performed by vehicles and the network control plane implemented by the UAV.Besides, we jointly explore the advantages of Medium Access Control(MAC) protocols in the link layer and routing schemes in the network layer to facilitate the multi-hop data transmission for the ground vehicles.Particularly, the network control plane in the UAV can manage the whole network effectively via fully exploiting the acquired network topology information and traffic requests from each vehicle, and implements various kinds of control based on different traffic demands, which can enhance the networking flexibility and scalability significantly in vehicular networks.Simulation results validate the advantages of the proposed scheme compared with existing methods.
基金Supported by Foundations of SiChuan Educational Committee under Grant No 13ZB0198the National Natural Science Foundation of China under Grant Nos 61104224,81373531,61104143 and 61573107The Science and Technology Fund Project of SWPU(2013XJR011)
文摘The influence of a node in a network can be characterized by its macroscopic properties such as eigenvector centrality. An issue of significant theoretical and practical interest is to modify the influence or roles of the nodes in a network, and recent advances indicate that this can be achieved by just controlling a subset of nodes： the socalled controllers. However, the relationship between the structural properties of a network and its controllability, e.g., the control of node importance, is still not well understood. Here we systematically＂ explore this relationship by constructing scale-free networks with a fixed degree sequence and tunable network characteristics. We calculate the relative size （nc＊） of the minimai controlling set required to controi the importance of each individual node in a network. It is found that while clustering has no significant impact on nc＊, changes in degree-degree correlations, heterogeneity and the average degree of networks demonstrate a discernible impact on its controllability.
文摘A microgrid(MG)refers to a set of loads,generation resources and energy storage systems acting as a controllable load or a generator to supply power and heating to a local area.The MG-generated power management is a central topic for MG design and operation.The existence of dispersed generation(DG)resources has faced MG management with new issues.Depending on the level of exchanges between an MG and the main grid,the MG operation states can be divided into independent or grid-connected ones.Energy management in MGs aims to supply power at the lowest cost for optimal load response.This study examines MG energy management in two operational modes of islanded and grid-connected,and proposes a structure with two control layers(primary and secondary)for energy management.At the principal level of control,the energy management system is determined individually for all MG by taking into consideration the probability constraints and RES uncertainty by the Weibull the probability density function(PDF),generation resources’power as well as the generation surplus and deficit of each MG.Then,the information of the power surplus and deficit of each MG must be sent to the central energy management system.To confirm the proposed structure,a case system with two MGs and a condensive load is simulated by using a multi-time harmony search algorithm.Several scenarios are applied to evaluate the performance of this algorithm.The findings clearly show the effectiveness of the proposed system in the energy management of several MGs,leading to the optimal performance of the resources per MG.Moreover,the proposed control scheme properly controls the MG and grid’s performance in their interactions and offers a high level of robustness,stable behavior under different conditions and high quality of power supply.
文摘With the rapid development of Chinas railway trains and heavy-haul railways, the construction scale of extra-long railway tunnels has been in the forefront of the world. This paper mainly discusses how to automatically identify the train state by ultrasonic ranging technology, and upload the train state information to the centralized control unit through PLC, so as to automatically control the lighting circuit in the tunnel to turn on or off, thus achieving the purposes of energy saving, low carbon and environmental protection, and prolonging the service life of equipment.
文摘In view of the practical application of centralized traffic control(CTC)system of the Beijing-Shanghai HSR and in combination with the line conditions and user requirements,the system is optimized in terms of route self-triggering polling frequency,train receiving route self-triggering timing,train departure route section processing,route self-triggering between yards,wireless route forecasting and automatic train number conversion,which improves the efficiency of automatic route setting of CTC system and the adaptability of high-density and long-major lines.At the same time,according to the intelligent development requirements of railways,the paper proposes the expectation for the centralized traffic control system of the Beijing-Shanghai HSR in terms of intelligent adjustment of TWD,information sharing with traction power supply supervisory control and data acquisition(SCADA)system/disaster monitoring system,intelligent linkage of posts,etc.
