Dear Editor,This letter deals with the stabilization of Lurie networked control systems with network-induced delays(NID).By constructing a twosided looped Lyapunov functional,a sufficient condition is derived to ensur...Dear Editor,This letter deals with the stabilization of Lurie networked control systems with network-induced delays(NID).By constructing a twosided looped Lyapunov functional,a sufficient condition is derived to ensure the absolute stability of the resultant closed-loop system under a state feedback controller.Then,based on this condition,a cone complementary linearisation(CCL)iterative algorithm is presented to design state feedback controller.It is shown via a numerical example that the proposed method can deliver less conservative results as well as fewer iterations if compared with existing ones.展开更多
Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely suppressed.Herein,to resolve the appeal ...Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely suppressed.Herein,to resolve the appeal issues,a free-standing anode with a"corrugated paper"shape on micro-scale and a topological crosslinking network on the submicron and nano-scale is designed.Essentially,an integrated three-dimensional electrode structure is constructed based on robust carbon nanotubes network with firmly anchored SiNPs via forming interlocking junctions.In which,the hierarchical interlocking structure is achieved by directional induction of the binder,which ensures well integration during cycling so that significantly enhances mechanical stability as well as electronic and ionic conductivity of electrodes.Benefiting from it,this anode exhibits outsta nding performance under harsh service conditions including high Si loading,ultrahigh areal capacity(33.2 mA h cm^(-2)),and high/low temperatures(-15-60℃),which significantly extends its practical prospect.Furthermore,the optimization mechanism of this electrode is explored to verify the crack-healing and structure-integration maintaining along cycling via a unique self-stabilization process.Thus,from both the fundamental and engineering views,this strategy offers a promising path to produce high-performance free-standing electrodes for flexible device applications especially facing volume effect challenges.展开更多
This paper presents a machine-learning-based speedup strategy for real-time implementation of model-predictive-control(MPC)in emergency voltage stabilization of power systems.Despite success in various applications,re...This paper presents a machine-learning-based speedup strategy for real-time implementation of model-predictive-control(MPC)in emergency voltage stabilization of power systems.Despite success in various applications,real-time implementation of MPC in power systems has not been successful due to the online control computation time required for large-sized complex systems,and in power systems,the computation time exceeds the available decision time used in practice by a large extent.This long-standing problem is addressed here by developing a novel MPC-based framework that i)computes an optimal strategy for nominal loads in an offline setting and adapts it for real-time scenarios by successive online control corrections at each control instant utilizing the latest measurements,and ii)employs a machine-learning based approach for the prediction of voltage trajectory and its sensitivity to control inputs,thereby accelerating the overall control computation by multiple times.Additionally,a realistic control coordination scheme among static var compensators(SVC),load-shedding(LS),and load tap-changers(LTC)is presented that incorporates the practical delayed actions of the LTCs.The performance of the proposed scheme is validated for IEEE 9-bus and 39-bus systems,with±20%variations in nominal loading conditions together with contingencies.We show that our proposed methodology speeds up the online computation by 20-fold,bringing it down to a practically feasible value(fraction of a second),making the MPC real-time and feasible for power system control for the first time.展开更多
Versatile module design of precursor networks enables flexible functionalization of nano-carbon electrode materials to meet the adaptable energy-storage demand. Functionalized heterogeneous networks are more likely to...Versatile module design of precursor networks enables flexible functionalization of nano-carbon electrode materials to meet the adaptable energy-storage demand. Functionalized heterogeneous networks are more likely to decompose by swift temperature programming together with predesign module removal, so high functionality/network transfer from precursor to carbon is still a work in progress. A pre-stabilization route is proposed here to enhance the network strength at early pyrolysis and pin up precursor-level functionalities on the final carbon. Such strategy successfully fixes more electroactive N(4.28-8.86 wt%) into the resultant carbon microspheres compared with non-pretreated carbon(2.89wt%), as well as achieves broad ion-accessible platforms of 1575-2269 m^(2)/g with preset structural superiorities. As a result, a typical acidic device reveals an outstanding specific capacitance of 383 F/g at 10 mV/s. Taking advantage of a novel LiNO_(3)-PAM polymer electrolyte, the upgraded symmetric device displays the maximum specific capacitance of 229 F/g, along with a boosted energy density of 41.1 Wh/kg at 643.4 W/kg. This work opens up a feasible insight into realizing highly efficient precursor/electrode design toward superior system with outstanding energy/power feature and temperature applicability.展开更多
New walking studies have been concerned with the multiplicity of pedestrian experiences.Some consider walking as an activity that unfolds as part of social life,allowing people to create relationships with others,wher...New walking studies have been concerned with the multiplicity of pedestrian experiences.Some consider walking as an activity that unfolds as part of social life,allowing people to create relationships with others,where multiple walking types can be identified depending on these relations.Some contributions,inspired by actor-network theory(ANT),suggest understanding this activity through a networked perspective that associates human and non-human actors,with a focus on their various and dynamic relations between them.The focus on stabilized networks,which emphasizes the recurrence of these relations,helps in identifying and extending themultiplicity of walking activity experience and emerging types.Despite this potential,ANT contributions are still limited.This paper aims to present the ANT potential in unpacking the multiplicity of the walking activity.It utilizes the case of Dahiyat Al Hussain park in Jordan and applies an ANT-inspired ethnographic approach to unpackwalking.It uses desk research,in-depth interviews,go-along interviews,and observations to engage with participants’views and experiences.By tracing the recurring relational patterns,the paper identifies three instances when walking practice can be considered as stabilized during network shaping,transformation,and interrelations.These stabilizations provide a nuanced perspective into the multiplicity of walking practices.展开更多
基金This work was supported by the National Natural Science Foundation of China(62173136)the Natural Science Foundation of Hunan Province(2020JJ2013,2021JJ50047)。
文摘Dear Editor,This letter deals with the stabilization of Lurie networked control systems with network-induced delays(NID).By constructing a twosided looped Lyapunov functional,a sufficient condition is derived to ensure the absolute stability of the resultant closed-loop system under a state feedback controller.Then,based on this condition,a cone complementary linearisation(CCL)iterative algorithm is presented to design state feedback controller.It is shown via a numerical example that the proposed method can deliver less conservative results as well as fewer iterations if compared with existing ones.
基金sponsored by the National Natural Science Foundation of China(21905221,21805221)the Suzhou Technological innovation of key industries-research and development of key technologies(SGC2021118)。
文摘Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely suppressed.Herein,to resolve the appeal issues,a free-standing anode with a"corrugated paper"shape on micro-scale and a topological crosslinking network on the submicron and nano-scale is designed.Essentially,an integrated three-dimensional electrode structure is constructed based on robust carbon nanotubes network with firmly anchored SiNPs via forming interlocking junctions.In which,the hierarchical interlocking structure is achieved by directional induction of the binder,which ensures well integration during cycling so that significantly enhances mechanical stability as well as electronic and ionic conductivity of electrodes.Benefiting from it,this anode exhibits outsta nding performance under harsh service conditions including high Si loading,ultrahigh areal capacity(33.2 mA h cm^(-2)),and high/low temperatures(-15-60℃),which significantly extends its practical prospect.Furthermore,the optimization mechanism of this electrode is explored to verify the crack-healing and structure-integration maintaining along cycling via a unique self-stabilization process.Thus,from both the fundamental and engineering views,this strategy offers a promising path to produce high-performance free-standing electrodes for flexible device applications especially facing volume effect challenges.
基金This work was supported in part by the National Science Foundation(NSF-CSSI-2004766,NSF-PFI-2141084).
文摘This paper presents a machine-learning-based speedup strategy for real-time implementation of model-predictive-control(MPC)in emergency voltage stabilization of power systems.Despite success in various applications,real-time implementation of MPC in power systems has not been successful due to the online control computation time required for large-sized complex systems,and in power systems,the computation time exceeds the available decision time used in practice by a large extent.This long-standing problem is addressed here by developing a novel MPC-based framework that i)computes an optimal strategy for nominal loads in an offline setting and adapts it for real-time scenarios by successive online control corrections at each control instant utilizing the latest measurements,and ii)employs a machine-learning based approach for the prediction of voltage trajectory and its sensitivity to control inputs,thereby accelerating the overall control computation by multiple times.Additionally,a realistic control coordination scheme among static var compensators(SVC),load-shedding(LS),and load tap-changers(LTC)is presented that incorporates the practical delayed actions of the LTCs.The performance of the proposed scheme is validated for IEEE 9-bus and 39-bus systems,with±20%variations in nominal loading conditions together with contingencies.We show that our proposed methodology speeds up the online computation by 20-fold,bringing it down to a practically feasible value(fraction of a second),making the MPC real-time and feasible for power system control for the first time.
基金financially supported by the National Natural Science Foundation of China(Nos.21875165,51772216,21905207 and 22172111)the Science and Technology Commission of Shanghai Municipality,China(Nos.20ZR1460300,19DZ2271500 and 22ZR1464100)+2 种基金Zhejiang Provincial Natural Science Foundation of China(No.LY19B010003)the Fundamental Research Funds for the Central Universitiesthe Large Equipment Test Foundation of Tongji University。
文摘Versatile module design of precursor networks enables flexible functionalization of nano-carbon electrode materials to meet the adaptable energy-storage demand. Functionalized heterogeneous networks are more likely to decompose by swift temperature programming together with predesign module removal, so high functionality/network transfer from precursor to carbon is still a work in progress. A pre-stabilization route is proposed here to enhance the network strength at early pyrolysis and pin up precursor-level functionalities on the final carbon. Such strategy successfully fixes more electroactive N(4.28-8.86 wt%) into the resultant carbon microspheres compared with non-pretreated carbon(2.89wt%), as well as achieves broad ion-accessible platforms of 1575-2269 m^(2)/g with preset structural superiorities. As a result, a typical acidic device reveals an outstanding specific capacitance of 383 F/g at 10 mV/s. Taking advantage of a novel LiNO_(3)-PAM polymer electrolyte, the upgraded symmetric device displays the maximum specific capacitance of 229 F/g, along with a boosted energy density of 41.1 Wh/kg at 643.4 W/kg. This work opens up a feasible insight into realizing highly efficient precursor/electrode design toward superior system with outstanding energy/power feature and temperature applicability.
文摘New walking studies have been concerned with the multiplicity of pedestrian experiences.Some consider walking as an activity that unfolds as part of social life,allowing people to create relationships with others,where multiple walking types can be identified depending on these relations.Some contributions,inspired by actor-network theory(ANT),suggest understanding this activity through a networked perspective that associates human and non-human actors,with a focus on their various and dynamic relations between them.The focus on stabilized networks,which emphasizes the recurrence of these relations,helps in identifying and extending themultiplicity of walking activity experience and emerging types.Despite this potential,ANT contributions are still limited.This paper aims to present the ANT potential in unpacking the multiplicity of the walking activity.It utilizes the case of Dahiyat Al Hussain park in Jordan and applies an ANT-inspired ethnographic approach to unpackwalking.It uses desk research,in-depth interviews,go-along interviews,and observations to engage with participants’views and experiences.By tracing the recurring relational patterns,the paper identifies three instances when walking practice can be considered as stabilized during network shaping,transformation,and interrelations.These stabilizations provide a nuanced perspective into the multiplicity of walking practices.
