The size of the Audio and Video(AV)content of the 8K program is four times larger than that of 4K content,providing viewers with a more ideal audiovisual experience while placing higher demands on the capability and e...The size of the Audio and Video(AV)content of the 8K program is four times larger than that of 4K content,providing viewers with a more ideal audiovisual experience while placing higher demands on the capability and efficiency of document preparation and processing,signal transmission,and scheduling.However,it is difficult to meet the high robustness requirements of 8K broadcast services because the existing broadcast system architecture is limited by efficiency,cost,and other factors.In this study,an 8K Ultra-High-Definition(UHD)TV program broadcast scheme was designed.The verification results show that the scheme is high quality,highly efficient,and robust.In particular,in the research,the file format normalizing module was first placed in the broadcast area instead of the file preparation area,and the low-compression transmission scheme of the all-IP signal JPEG XS was designed in the signal transmission area for improving the efficiency of the scheme.Next,to reduce the impact on the robustness of broadcast services,the broadcast control logic of the broadcast core components is optimized.Finally,a series of 8K TV program broadcasting systems have been implemented and their performance has been verified.The results show that the system meets the efficiency and robustness requirements of a high-quality 8K AV broadcast system,and thus has a high degree of practicability.展开更多
This paper studies the target controllability of multilayer complex networked systems,in which the nodes are highdimensional linear time invariant(LTI)dynamical systems,and the network topology is directed and weighte...This paper studies the target controllability of multilayer complex networked systems,in which the nodes are highdimensional linear time invariant(LTI)dynamical systems,and the network topology is directed and weighted.The influence of inter-layer couplings on the target controllability of multi-layer networks is discussed.It is found that even if there exists a layer which is not target controllable,the entire multi-layer network can still be target controllable due to the inter-layer couplings.For the multi-layer networks with general structure,a necessary and sufficient condition for target controllability is given by establishing the relationship between uncontrollable subspace and output matrix.By the derived condition,it can be found that the system may be target controllable even if it is not state controllable.On this basis,two corollaries are derived,which clarify the relationship between target controllability,state controllability and output controllability.For the multi-layer networks where the inter-layer couplings are directed chains and directed stars,sufficient conditions for target controllability of networked systems are given,respectively.These conditions are easier to verify than the classic criterion.展开更多
This paper studies the controllability of networked systems,in which the nodes are heterogeneous high-dimensional dynamical systems,and the links between nodes are multi-relational.Our aim is to find controllability c...This paper studies the controllability of networked systems,in which the nodes are heterogeneous high-dimensional dynamical systems,and the links between nodes are multi-relational.Our aim is to find controllability criteria for heterogeneous networks with multi-relational links beyond those only applicable to networks with single-relational links.It is found a network with multi-relational links can be controllable even if each single-relational network topology is uncontrollable,and vice versa.Some sufficient and necessary conditions are derived for the controllability of multi-relational networks with heterogeneous dynamical nodes.For two typical multi-relational networks with star-chain topology and star-circle topology,some easily verified conditions are presented.For illustration and verification,several examples are presented.These findings provide practical insights for the analysis and control of multi-relational complex systems.展开更多
[目的]系统评价产妇水中分娩真实体验的质性研究,为更好地开展产妇水中分娩工作提供依据。[方法]计算机检索Cochrane Library、JBI循证卫生保健国际合作中心图书馆、PubMed、EMbase、Scopus、Web of Science、护理及相关健康领域文献积...[目的]系统评价产妇水中分娩真实体验的质性研究,为更好地开展产妇水中分娩工作提供依据。[方法]计算机检索Cochrane Library、JBI循证卫生保健国际合作中心图书馆、PubMed、EMbase、Scopus、Web of Science、护理及相关健康领域文献积累索引数据库、中国知网(CNKI)、中国生物医学文献数据库、万方、维普,搜集有关产妇水中分娩真实体验的质性研究,检索年限为建库至2020年7月。采用澳大利亚JBI循证卫生保健中心质性研究质量评价标准评价文献质量,采用汇集性整合的方法进行结果整合。[结果]共纳入6篇研究,提炼出52个完好明确的研究结果,将相似的研究结果归纳形成9个新类别,得出4个整合结果:决定水中分娩前的经历;水中分娩对产妇的影响;水中分娩对婴儿的影响;实践经验及提议。[结论]医生及助产士应多关注产妇在水中分娩时的真实心理体验,决策前给予充分科学的信息支持,不断改进水中分娩的实践方案,加强人文关怀,使产妇获得优质的分娩体验。展开更多
In this paper,we investigate formation tracking control of autonomous underwater vehicles(AUVs)with model parameter uncertainties and external disturbances.The external disturbances due to the wind,waves,and ocean cur...In this paper,we investigate formation tracking control of autonomous underwater vehicles(AUVs)with model parameter uncertainties and external disturbances.The external disturbances due to the wind,waves,and ocean currents are combined with the model parameter uncertainties as a compound disturbance.Then a disturbance observer(DO)is introduced to estimate the compound disturbance,which can be achieved within a finite time independent of the initial estimation error.Based on a DO,a novel fixed-time sliding control scheme is developed,by which the follower vehicle can track the leader vehicle with all the states globally stabilized within a given settling time.The effectiveness and performance of the method are demonstrated by numerical simulations.展开更多
This paper investigates the heading tracking problem of surface vehicles with unknown model parameters.Based on finite/fixed-time control theories and in the context of command filtered control,two novel adaptive cont...This paper investigates the heading tracking problem of surface vehicles with unknown model parameters.Based on finite/fixed-time control theories and in the context of command filtered control,two novel adaptive control laws are developed by which the vehicle can track the desired heading within settling time with all signals of the closed-loop system are uniformly bounded.The effectiveness and performance of the schemes are demonstrated by simulations and comparison studies.展开更多
This paper addresses the problem of the input design of large-scale complex networks.Two types of network components,redundant inaccessible strongly connected component(RISCC)and intermittent inaccessible strongly con...This paper addresses the problem of the input design of large-scale complex networks.Two types of network components,redundant inaccessible strongly connected component(RISCC)and intermittent inaccessible strongly connected component(IISCC)are defined,and a subnetwork called a driver network is developed.Based on these,an efficient method is proposed to find the minimum number of controlled nodes to achieve structural complete controllability of a network,in the case that each input can act on multiple state nodes.The range of the number of input nodes to achieve minimal control,and the configuration method(the connection between the input nodes and the controlled nodes)are presented.All possible input solutions can be obtained by this method.Moreover,we give an example and some experiments on real-world networks to illustrate the effectiveness of the method.展开更多
The stabilization properties of various typical complex dynamical networks composed of chaotic nodes are theoretically investigated and numerically simulated in detail. Some local stability properties of such pinned n...The stabilization properties of various typical complex dynamical networks composed of chaotic nodes are theoretically investigated and numerically simulated in detail. Some local stability properties of such pinned networks are derived and the valid stability regions are estimated based on eigenvalue analysis. Numerical simulations of such networks are given to explain why significantly less local controllers are needed by the specifically pinning scheme, which pins the most highly connected nodes in scale-free networks, than that required by the randomly pinning scheme. Also, it is explained why there is no significant difference between the two schemes for controlling random-graph networks and small-world networks.展开更多
In recent years, researches published on hydrophobic materials increase rapidly, wherein the method for changing hydrophobicity by modifying a micro-array structure on the surface of the material also has been propose...In recent years, researches published on hydrophobic materials increase rapidly, wherein the method for changing hydrophobicity by modifying a micro-array structure on the surface of the material also has been proposed. Of course, if it is possible for us to quantitatively analyse and evaluate hydrophobicity of different structures of one certain material at first, this task will greatly optimize the design of actual structures. In this work, we used the algorithm for Laminar Two-Phase Flow, Horizontal-set method integrated in COMSOL to build two single-pore simulation structures in different shapes and simulated the behaviour of the liquid transition from Cassie-state to Wenzel-state during the impregnation process. After that, the intrinsic contact angle of Structure T (a porous structure with a T-shaped sectional profile) was obtained under a certain pressure which maintained liquids in Cassie-state. Meanwhile, two equilibrium states of the liquid-air interface as well as two different patterns of the equilibrium state disrupting were found in Structure R (a porous structure with a Chamfered T-shaped sectional profile). Simulation results show that the modelling method can be applied for simulating the hydrophobicity of different porous structures and optimizing the procedures for the design of the micro-array efficiently.展开更多
Connected and automated vehicles(CAVs)have the ability of gathering and sharing traffic information and vehicle state with neighbouring vehicles.Therefore,CAVs are believed to be a promising technology to deliver grea...Connected and automated vehicles(CAVs)have the ability of gathering and sharing traffic information and vehicle state with neighbouring vehicles.Therefore,CAVs are believed to be a promising technology to deliver greater safety and mobility benefits to the next generation intelligent transportation systems(ITSs).Especially,when empowered by artificial intelligence(AI)and big data(BD)technologies,there would be more possibilities for smarter ITSs.展开更多
INTRODUCTION Microparticles （MPs） were increased in patients with coronary heart disease （CHD）,with the subtypes and quantity of MPs variate in different types of CHD.There were emerging reports indicating that MP...INTRODUCTION Microparticles （MPs） were increased in patients with coronary heart disease （CHD）,with the subtypes and quantity of MPs variate in different types of CHD.There were emerging reports indicating that MPs may play important roles in the pathogenesis of CHD.Here in this review we summarized the pro-inflammation,pro-coagulation effects of MPs,as well as their impacts on endothelial function and angiogenesis.MPs have the potential of being powerful diagnostic biomarkers and therapeutic tools in CHD patients in the future.展开更多
Charge-changing cross section(σcc)measurements via the transmission method have recently seen significant progress with the aim of determining the charge radii of exotic nuclei.In this work,we report a newσcc measur...Charge-changing cross section(σcc)measurements via the transmission method have recently seen significant progress with the aim of determining the charge radii of exotic nuclei.In this work,we report a newσcc measurement of 304(9)MeV/nucleon^(28)Si on carbon at the second Radioactive Ion Beam Line in Lanzhou(RIBLL2)and describe the data analysis procedure in detail.This procedure is essential for evaluating the systematic uncertainty in the transmission method.The determinedσcc of 1125(11)mb is found to be consistent with the existing data at similar energies.The present work will serve as a reference forσcc determinations at RIBLL2.展开更多
Since the pioneering use of radioactive ion beams(RIB)in the1980s at Lawrence Berkeley National Laboratory in USA,production and investigation of exotic nuclei far from stability have become possible for a wide range ...Since the pioneering use of radioactive ion beams(RIB)in the1980s at Lawrence Berkeley National Laboratory in USA,production and investigation of exotic nuclei far from stability have become possible for a wide range of nuclear chart.Over the past few decades,the RIB has triggered tremendous advancements in the study of exotic nuclei.For instance,over 3300 nuclides have been discovered[1],with a substantial number of them produced by employing RIBs.Experimentally,there are several methods to generate radioactive nuclei.Among them,the in-flight production methods,specifically projectile fragmentation and in-flight fission,are proven to be two of the most crucial approaches.In-flight methods have been widely used to create the radioactive nuclei lying away from the valley of stability,such as those situated on or close to the r-process path(e.g.,see Refs.[2-4]),thereby allowing scientists to explore the previously inaccessible nuclear territory.In the past few decades,a number of fragment separators have been constructed worldwide in order to produce exotic nuclei utilizing the in-flight techniques[5].展开更多
文摘The size of the Audio and Video(AV)content of the 8K program is four times larger than that of 4K content,providing viewers with a more ideal audiovisual experience while placing higher demands on the capability and efficiency of document preparation and processing,signal transmission,and scheduling.However,it is difficult to meet the high robustness requirements of 8K broadcast services because the existing broadcast system architecture is limited by efficiency,cost,and other factors.In this study,an 8K Ultra-High-Definition(UHD)TV program broadcast scheme was designed.The verification results show that the scheme is high quality,highly efficient,and robust.In particular,in the research,the file format normalizing module was first placed in the broadcast area instead of the file preparation area,and the low-compression transmission scheme of the all-IP signal JPEG XS was designed in the signal transmission area for improving the efficiency of the scheme.Next,to reduce the impact on the robustness of broadcast services,the broadcast control logic of the broadcast core components is optimized.Finally,a series of 8K TV program broadcasting systems have been implemented and their performance has been verified.The results show that the system meets the efficiency and robustness requirements of a high-quality 8K AV broadcast system,and thus has a high degree of practicability.
基金supported by the National Natural Science Foundation of China (U1808205)Hebei Natural Science Foundation (F2000501005)。
文摘This paper studies the target controllability of multilayer complex networked systems,in which the nodes are highdimensional linear time invariant(LTI)dynamical systems,and the network topology is directed and weighted.The influence of inter-layer couplings on the target controllability of multi-layer networks is discussed.It is found that even if there exists a layer which is not target controllable,the entire multi-layer network can still be target controllable due to the inter-layer couplings.For the multi-layer networks with general structure,a necessary and sufficient condition for target controllability is given by establishing the relationship between uncontrollable subspace and output matrix.By the derived condition,it can be found that the system may be target controllable even if it is not state controllable.On this basis,two corollaries are derived,which clarify the relationship between target controllability,state controllability and output controllability.For the multi-layer networks where the inter-layer couplings are directed chains and directed stars,sufficient conditions for target controllability of networked systems are given,respectively.These conditions are easier to verify than the classic criterion.
基金supported by the National Natural Science Foundation of China(61573077,U1808205)China Scholarship Council(202308130119)Natural Science Foundation of Hebei Province(F2022501005)。
文摘This paper studies the controllability of networked systems,in which the nodes are heterogeneous high-dimensional dynamical systems,and the links between nodes are multi-relational.Our aim is to find controllability criteria for heterogeneous networks with multi-relational links beyond those only applicable to networks with single-relational links.It is found a network with multi-relational links can be controllable even if each single-relational network topology is uncontrollable,and vice versa.Some sufficient and necessary conditions are derived for the controllability of multi-relational networks with heterogeneous dynamical nodes.For two typical multi-relational networks with star-chain topology and star-circle topology,some easily verified conditions are presented.For illustration and verification,several examples are presented.These findings provide practical insights for the analysis and control of multi-relational complex systems.
文摘[目的]系统评价产妇水中分娩真实体验的质性研究,为更好地开展产妇水中分娩工作提供依据。[方法]计算机检索Cochrane Library、JBI循证卫生保健国际合作中心图书馆、PubMed、EMbase、Scopus、Web of Science、护理及相关健康领域文献积累索引数据库、中国知网(CNKI)、中国生物医学文献数据库、万方、维普,搜集有关产妇水中分娩真实体验的质性研究,检索年限为建库至2020年7月。采用澳大利亚JBI循证卫生保健中心质性研究质量评价标准评价文献质量,采用汇集性整合的方法进行结果整合。[结果]共纳入6篇研究,提炼出52个完好明确的研究结果,将相似的研究结果归纳形成9个新类别,得出4个整合结果:决定水中分娩前的经历;水中分娩对产妇的影响;水中分娩对婴儿的影响;实践经验及提议。[结论]医生及助产士应多关注产妇在水中分娩时的真实心理体验,决策前给予充分科学的信息支持,不断改进水中分娩的实践方案,加强人文关怀,使产妇获得优质的分娩体验。
基金supported in part by the National Natural Science Foundation of China(61573077,U1808205)the National Key Research and Development Program of China(2017YFA0700300)
文摘In this paper,we investigate formation tracking control of autonomous underwater vehicles(AUVs)with model parameter uncertainties and external disturbances.The external disturbances due to the wind,waves,and ocean currents are combined with the model parameter uncertainties as a compound disturbance.Then a disturbance observer(DO)is introduced to estimate the compound disturbance,which can be achieved within a finite time independent of the initial estimation error.Based on a DO,a novel fixed-time sliding control scheme is developed,by which the follower vehicle can track the leader vehicle with all the states globally stabilized within a given settling time.The effectiveness and performance of the method are demonstrated by numerical simulations.
基金supported by the National Natural Science Foundation of China(U1808205)the Fundamental Research Funds for the Central Universities(N2023011)+1 种基金the Youth Foundation of Hebei Educational Committee(QN2020522)the Natural Science Foundation of Hebei Province(F2020501018)。
文摘This paper investigates the heading tracking problem of surface vehicles with unknown model parameters.Based on finite/fixed-time control theories and in the context of command filtered control,two novel adaptive control laws are developed by which the vehicle can track the desired heading within settling time with all signals of the closed-loop system are uniformly bounded.The effectiveness and performance of the schemes are demonstrated by simulations and comparison studies.
基金supported in part by the National Natural Science Foundation of China(U1808205,62173079)the Natural Science Foundation of Hebei Province of China(F2000501005)。
文摘This paper addresses the problem of the input design of large-scale complex networks.Two types of network components,redundant inaccessible strongly connected component(RISCC)and intermittent inaccessible strongly connected component(IISCC)are defined,and a subnetwork called a driver network is developed.Based on these,an efficient method is proposed to find the minimum number of controlled nodes to achieve structural complete controllability of a network,in the case that each input can act on multiple state nodes.The range of the number of input nodes to achieve minimal control,and the configuration method(the connection between the input nodes and the controlled nodes)are presented.All possible input solutions can be obtained by this method.Moreover,we give an example and some experiments on real-world networks to illustrate the effectiveness of the method.
基金This work was supported by the National Natural Science Foundation of China （61273107, 61573077, 61503003）, the Dalian Leading, Dalian, China, the Doctoral Foundation of Tianjin Normal University （135202XB1613）, the Postdoctoral Science Foundation of China （2015M581332）, and the Natural Science Foundation of Anhui Province （150808. 5QF126）
基金the National Natural Science Foundation of China (No.60774088, 60504017)the Specialized Research Fund for theDoctoral Program of Higher Education of China (No.20050055013)the Program for New Century Excellent Talents of China (NCET)
文摘The stabilization properties of various typical complex dynamical networks composed of chaotic nodes are theoretically investigated and numerically simulated in detail. Some local stability properties of such pinned networks are derived and the valid stability regions are estimated based on eigenvalue analysis. Numerical simulations of such networks are given to explain why significantly less local controllers are needed by the specifically pinning scheme, which pins the most highly connected nodes in scale-free networks, than that required by the randomly pinning scheme. Also, it is explained why there is no significant difference between the two schemes for controlling random-graph networks and small-world networks.
文摘In recent years, researches published on hydrophobic materials increase rapidly, wherein the method for changing hydrophobicity by modifying a micro-array structure on the surface of the material also has been proposed. Of course, if it is possible for us to quantitatively analyse and evaluate hydrophobicity of different structures of one certain material at first, this task will greatly optimize the design of actual structures. In this work, we used the algorithm for Laminar Two-Phase Flow, Horizontal-set method integrated in COMSOL to build two single-pore simulation structures in different shapes and simulated the behaviour of the liquid transition from Cassie-state to Wenzel-state during the impregnation process. After that, the intrinsic contact angle of Structure T (a porous structure with a T-shaped sectional profile) was obtained under a certain pressure which maintained liquids in Cassie-state. Meanwhile, two equilibrium states of the liquid-air interface as well as two different patterns of the equilibrium state disrupting were found in Structure R (a porous structure with a Chamfered T-shaped sectional profile). Simulation results show that the modelling method can be applied for simulating the hydrophobicity of different porous structures and optimizing the procedures for the design of the micro-array efficiently.
文摘Connected and automated vehicles(CAVs)have the ability of gathering and sharing traffic information and vehicle state with neighbouring vehicles.Therefore,CAVs are believed to be a promising technology to deliver greater safety and mobility benefits to the next generation intelligent transportation systems(ITSs).Especially,when empowered by artificial intelligence(AI)and big data(BD)technologies,there would be more possibilities for smarter ITSs.
基金The study was supported by grants from the National Natural Science Foundation of China （No. 81300076） and the Beijing Natural Science Foundation （No. 7132195）.
文摘INTRODUCTION Microparticles （MPs） were increased in patients with coronary heart disease （CHD）,with the subtypes and quantity of MPs variate in different types of CHD.There were emerging reports indicating that MPs may play important roles in the pathogenesis of CHD.Here in this review we summarized the pro-inflammation,pro-coagulation effects of MPs,as well as their impacts on endothelial function and angiogenesis.MPs have the potential of being powerful diagnostic biomarkers and therapeutic tools in CHD patients in the future.
基金Supported by the National Natural Science Foundation of China(U1832211,11961141004,11922501,11475014,11905260)the Western Light Project of Chinese Academy of Sciencesthe Natural Science Foundation of Anhui Province,China(2008085MA17)。
文摘Charge-changing cross section(σcc)measurements via the transmission method have recently seen significant progress with the aim of determining the charge radii of exotic nuclei.In this work,we report a newσcc measurement of 304(9)MeV/nucleon^(28)Si on carbon at the second Radioactive Ion Beam Line in Lanzhou(RIBLL2)and describe the data analysis procedure in detail.This procedure is essential for evaluating the systematic uncertainty in the transmission method.The determinedσcc of 1125(11)mb is found to be consistent with the existing data at similar energies.The present work will serve as a reference forσcc determinations at RIBLL2.
基金supported partially by the National Natural Science Foundation of China(12325506,11922501,U1832211,11961141004,and 11905260)the Western Light Project of the Chinese Academy of Sciencesthe open research project of CAS large research infrastructures。
文摘Since the pioneering use of radioactive ion beams(RIB)in the1980s at Lawrence Berkeley National Laboratory in USA,production and investigation of exotic nuclei far from stability have become possible for a wide range of nuclear chart.Over the past few decades,the RIB has triggered tremendous advancements in the study of exotic nuclei.For instance,over 3300 nuclides have been discovered[1],with a substantial number of them produced by employing RIBs.Experimentally,there are several methods to generate radioactive nuclei.Among them,the in-flight production methods,specifically projectile fragmentation and in-flight fission,are proven to be two of the most crucial approaches.In-flight methods have been widely used to create the radioactive nuclei lying away from the valley of stability,such as those situated on or close to the r-process path(e.g.,see Refs.[2-4]),thereby allowing scientists to explore the previously inaccessible nuclear territory.In the past few decades,a number of fragment separators have been constructed worldwide in order to produce exotic nuclei utilizing the in-flight techniques[5].
