We consider a model of network formation as a stochastic game with random duration proposed initially in Sun and Parilina(Autom Remote Control 82(6):1065–1082,2021).In the model,the leader first suggests a joint proj...We consider a model of network formation as a stochastic game with random duration proposed initially in Sun and Parilina(Autom Remote Control 82(6):1065–1082,2021).In the model,the leader first suggests a joint project to other players,i.e.,the network connecting them.Second,the players are allowed to form fresh links with each other updating the initially proposed network.The stage payoff of any player is defined depending on the network structure.There are two types of randomness in the network formation process:(i)links may fail to be formed with different probabilities although players intend to establish them,(ii)the game process may terminate at any stage or transit to the next stage with a certain probability distribution.Finally,a network is formed as a result of players’decisions and realization of random variables.The cooperative version of the stochastic game is investigated.In particular,we examine the properties of subgame consistency as well as strong subgame consistency of the core.We provide a payment mechanism or regularization of the core elements to sustain its subgame consistency and avoid the player’s deviations from the cooperative trajectory.In addition,the distribution procedure of the core elements is regularized in case there are negative payments to achieve only nonnegative payments to the players at any stage.The sufficient condition of a strongly subgame consistent core is also obtained.We illustrate our theoretical results with a numerical example.展开更多
Many phenomena show that in a favorable circumstance an agent still has an updating possibility, and in an unfavor- able circumstance an agent also has a possibility of holding its own state and reselecting its neighb...Many phenomena show that in a favorable circumstance an agent still has an updating possibility, and in an unfavor- able circumstance an agent also has a possibility of holding its own state and reselecting its neighbors. To describe this kind of phenomena an Ising model on evolution networks was presented and used for consensus formation and separation of opinion groups in human population. In this model the state-holding probability p and selection-rewiring probability q were introduced. The influence of this mixed dynamics of spin flips and network rewiring on the ordering behavior of the model was investigated, p hinders ordering of opinion networks and q accelerates the dynamical process of networks. Influence of q on the ordering and separating stems from its effect on average path length of networks.展开更多
One fundamental problem in computer vision and image processing is modeling the image formation of a camera, i.e., mapping a point in three-dimensional space to its projected position on the camera’s image plane. If ...One fundamental problem in computer vision and image processing is modeling the image formation of a camera, i.e., mapping a point in three-dimensional space to its projected position on the camera’s image plane. If the relationship between the space and the image plane is assumed to be linear, the relationship can be expressed in terms of a transfor-mation matrix and the matrix is often identified by regression. In this paper, we show that the space-to-image relation-ship in a camera can be modeled by a simple neural network. Unlike most other cases employing neural networks, the structure of the network is optimized so as for each link between neurons to have a physical meaning. This makes it possible to effectively initialize link weights and quickly train the network.展开更多
Coordinated signal processing can obtain a huge transmission gain for Fog Radio Access Networks(F-RANs).However,integrating into large scale,it will lead to high computation complexity in channel estimation and spectr...Coordinated signal processing can obtain a huge transmission gain for Fog Radio Access Networks(F-RANs).However,integrating into large scale,it will lead to high computation complexity in channel estimation and spectral efficiency loss in transmission performance.Thus,a joint cluster formation and channel estimation scheme is proposed in this paper.Considering research remote radio heads(RRHs)centred serving scheme,a coalition game is formulated in order to maximize the spectral efficiency of cooperative RRHs under the conditions of balancing the data rate and the cost of channel estimation.As the cost influences to the necessary consumption of training length and estimation error.Particularly,an iterative semi-blind channel estimation and symbol detection approach is designed by expectation maximization algorithm,where the channel estimation process is initialized by subspace method with lower pilot length.Finally,the simulation results show that a stable cluster formation is established by our proposed coalition game method and it outperforms compared with full coordinated schemes.展开更多
This study investigated the characteristics and formation of the online social trust network of Epinions.com, a general consumer review site. An analysis of the static structure of this social trust network revealed a...This study investigated the characteristics and formation of the online social trust network of Epinions.com, a general consumer review site. An analysis of the static structure of this social trust network revealed a high clustering coefficient, short average path length, and power-law degree distribution;it is therefore a small-world and scale-free trust network. The dynamic evolutionary characteristics of the online social network (OSN) were also examined. The results showed that the scale of the network followed a sigmoidal curve;the average degree of the network was nonconstant and changed into a bell-shaped distribution;the density of the network decreased and subsequently stabilized;and user trust diffusion in the network conformed to the Bass model. Finally, the formation of trust within the network was researched at the overall network (macro) and individual user (micro) levels. Compared with their accumulated contribution and reputation, user activeness had a larger effect on trust formation in OSNs, indicating a “diminishing returns” phenomenon. This phenomenon contrasts with the Matthew effect (i.e. , the more reputation a person has, the more likely he or she is to be trusted) in real-world social networks.展开更多
Significant advancements have been made in metal-organic frameworks(MOFs)for proton conductivity in proton exchange membrane fuel cells;however,a comprehensive and rational design road map for these materials remains ...Significant advancements have been made in metal-organic frameworks(MOFs)for proton conductivity in proton exchange membrane fuel cells;however,a comprehensive and rational design road map for these materials remains under explored,particularly regarding the quantitative contributions of internal structural factors(proton donor-acceptor types and spatial distances)and external environmental factors(temperature and humidity)to hydrogen-bond formation.In this study,the hydrogen-bonded network formation potential(ФH)is proposed based on these factors to establish structure-property relationship of MOFs via artificial neural network(ANN)model,by which a linear function relationship has been fitted to facilitate the rational design of MOFs,providing a simple assessment of proton conductivity performance in reverse.As a proof of concept,UiO-66-NH_(2)-SO_(3)H with varying group ratios was fabricated,and UiO-66-NH_(2)-SO_(3)H-1:5 exhibited favorable proton conductivity(0.08 S∙cm-1)due to the favorable matching of Brönsted acid-base pairs,which facilitates the extensive formation of hydrogen-bonded networks.The proposed hydrogen-bonded network formation potential is expected to advance the design and synthesis of MOF-based proton-conductive materials,serving as a valuable index for the proton exchange membrane fuel cell research community.展开更多
In this paper,attitude coordinated tracking control algorithms for multiple spacecraft formation are investigated with consideration of parametric uncertainties,external disturbances,communication delays and actuator ...In this paper,attitude coordinated tracking control algorithms for multiple spacecraft formation are investigated with consideration of parametric uncertainties,external disturbances,communication delays and actuator saturation.Initially,a sliding mode delay-dependent attitude coordinated controller is proposed under bounded external disturbances.However,neither inertia uncertainty nor actuator constraint has been taken into account.Then,a robust saturated delaydependent attitude coordinated control law is further derived,where uncertainties and external disturbances are handled by Chebyshev neural networks（CNN）.In addition,command filter technique is introduced to facilitate the backstepping design procedure,through which actuator saturation problem is solved.Thus the spacecraft in the formation are able to track the reference attitude trajectory even in the presence of time-varying communication delays.Rigorous analysis is presented by using Lyapunov-Krasovskii approach to demonstrate the stability of the closed-loop system under both control algorithms.Finally,the numerical examples are carried out to illustrate the efficiency of the theoretical results.展开更多
This paper is concerned with the formation control problem of multiple underactuated surface vessels moving in a leader-follower formation. The formation is achieved by the follower to track a virtual target defined r...This paper is concerned with the formation control problem of multiple underactuated surface vessels moving in a leader-follower formation. The formation is achieved by the follower to track a virtual target defined relative to the leader. A robust adaptive target tracking law is proposed by using neural network and backstepping techniques. The advantage of the proposed control scheme is that the uncertain nonlinear dynamics caused by Coriolis/centripetal forces, nonlinear damping, unmodeled hydrodynamics and disturbances from the environment can be compensated by on line learning. Based on Lyapunov analysis, the proposed controller guarantees the tracking errors converge to a small neighborhood of the origin. Simulation results demonstrate the effectiveness of the control strategy.展开更多
Family farm is an essential modern agricultural micro economic organization. With accelerated advance of rural land circulation and large-scale management,family farm gradually becomes an important choice for modern a...Family farm is an essential modern agricultural micro economic organization. With accelerated advance of rural land circulation and large-scale management,family farm gradually becomes an important choice for modern agricultural management. With ANT as theoretical basis,this paper analyzed formation of family farms in the joint action of endogenous and exogenous forces. Besides,it analyzed Fengsheng Tobacco Family Farm of Guyue Town in Zhucheng City of Shandong Province and Li Chunfeng's Family Farm in Songjiang District of Shanghai.Research indicates that different regional environments bring about different actors and also different formation paths for family farms.展开更多
Learning from the conventional practice of network IP address format, this paper proposed an IP-format-based algorithm for ZigBee energy-balanced routing protocol optimization. The algorithm combines node’s cluster a...Learning from the conventional practice of network IP address format, this paper proposed an IP-format-based algorithm for ZigBee energy-balanced routing protocol optimization. The algorithm combines node’s cluster address and node’s network short address into a new address and divides the address’s field as IP-format. So that the address will contain information of the network’s topology and provide decision base for a routing algorithm to optimize the original algorithm selection criteria. Meanwhile, in order to improve the ratio of valid data packets and reduce routing overhead, the new algorithm controls the general direction and the number of hops of the RREQ packets to reduce unwarranted data packet transmission. Finally, the simulation carried out on NS platform demonstrates the algorithm’s superiority on network’s delay jitter, overhead and residual energy.展开更多
The ability of the monolithic satellite,satellite orbit(especially GEO),and radio resource are very limited,so the development of distributed satellite cluster network(DSCN) receives more and more worldwide attention....The ability of the monolithic satellite,satellite orbit(especially GEO),and radio resource are very limited,so the development of distributed satellite cluster network(DSCN) receives more and more worldwide attention.In this paper,DSCN is surveyed and the study status of DSCN architecture design is summarized.The formation flying of spacecrafts,reconfiguration,networking,and applied research on distributed satellite spacecraft are described in detail.The DSCN will provide a great technology innovation for space information network,satellite communications,satellite navigation,deep space exploration,and space remote sensing.In addition,this paper points out future trends of the DSCN development.展开更多
After long-term waterflooding in unconsolidated sandstone reservoir, the high-permeability channels are easy to evolve, which leads to a significant reduction in water flooding efficiency and a poor oilfield developme...After long-term waterflooding in unconsolidated sandstone reservoir, the high-permeability channels are easy to evolve, which leads to a significant reduction in water flooding efficiency and a poor oilfield development effect. The current researches on the formation parameters variation are mainly based on the experiment analysis or field statistics, while lacking quantitative research of combining microcosmic and macroscopic mechanism. A network model was built after taking the detachment and entrapment mechanisms of particles in unconsolidated sandstone reservoir into consideration. Then a coupled mathematical model for the formation parameters variation was established based on the network modeling and the model of fluids flowing in porous media. The model was solved by a finite-difference method and the Gauss-Seidel iterative technique. A novel field-scale reservoir numerical simulator was written in Fortran 90 and it can be used to predict 1) the evolvement of high-permeability channels caused by particles release and migration in the long-term water flooding process, and 2) well production performances and remaining oil distribution. In addition, a series of oil field examples with inverted nine-spot pattern was made on the new numerical simulator. The results show that the high-permeability channels are more likely to develop along the main streamlines between the injection and production wells, and the formation parameters variation has an obvious influence on the remaining oil distribution.展开更多
基金supported by the Russian Science Foundation(No.22-21-00346)。
文摘We consider a model of network formation as a stochastic game with random duration proposed initially in Sun and Parilina(Autom Remote Control 82(6):1065–1082,2021).In the model,the leader first suggests a joint project to other players,i.e.,the network connecting them.Second,the players are allowed to form fresh links with each other updating the initially proposed network.The stage payoff of any player is defined depending on the network structure.There are two types of randomness in the network formation process:(i)links may fail to be formed with different probabilities although players intend to establish them,(ii)the game process may terminate at any stage or transit to the next stage with a certain probability distribution.Finally,a network is formed as a result of players’decisions and realization of random variables.The cooperative version of the stochastic game is investigated.In particular,we examine the properties of subgame consistency as well as strong subgame consistency of the core.We provide a payment mechanism or regularization of the core elements to sustain its subgame consistency and avoid the player’s deviations from the cooperative trajectory.In addition,the distribution procedure of the core elements is regularized in case there are negative payments to achieve only nonnegative payments to the players at any stage.The sufficient condition of a strongly subgame consistent core is also obtained.We illustrate our theoretical results with a numerical example.
基金supported by the National Natural Science Foundation of China(Grant No.11304123)the Scientific Research Foundation of Jianghan University(Grant No.2010014)
文摘Many phenomena show that in a favorable circumstance an agent still has an updating possibility, and in an unfavor- able circumstance an agent also has a possibility of holding its own state and reselecting its neighbors. To describe this kind of phenomena an Ising model on evolution networks was presented and used for consensus formation and separation of opinion groups in human population. In this model the state-holding probability p and selection-rewiring probability q were introduced. The influence of this mixed dynamics of spin flips and network rewiring on the ordering behavior of the model was investigated, p hinders ordering of opinion networks and q accelerates the dynamical process of networks. Influence of q on the ordering and separating stems from its effect on average path length of networks.
文摘One fundamental problem in computer vision and image processing is modeling the image formation of a camera, i.e., mapping a point in three-dimensional space to its projected position on the camera’s image plane. If the relationship between the space and the image plane is assumed to be linear, the relationship can be expressed in terms of a transfor-mation matrix and the matrix is often identified by regression. In this paper, we show that the space-to-image relation-ship in a camera can be modeled by a simple neural network. Unlike most other cases employing neural networks, the structure of the network is optimized so as for each link between neurons to have a physical meaning. This makes it possible to effectively initialize link weights and quickly train the network.
基金supported in part by the State Major Science and Technology Special Project(Grant No.2018ZX03001025)the National Natural Science Foundation of China(No.61831002 and No.61671074)the Fundamental Research Funds for the Central Universities under Grant No.2018XKJC01
文摘Coordinated signal processing can obtain a huge transmission gain for Fog Radio Access Networks(F-RANs).However,integrating into large scale,it will lead to high computation complexity in channel estimation and spectral efficiency loss in transmission performance.Thus,a joint cluster formation and channel estimation scheme is proposed in this paper.Considering research remote radio heads(RRHs)centred serving scheme,a coalition game is formulated in order to maximize the spectral efficiency of cooperative RRHs under the conditions of balancing the data rate and the cost of channel estimation.As the cost influences to the necessary consumption of training length and estimation error.Particularly,an iterative semi-blind channel estimation and symbol detection approach is designed by expectation maximization algorithm,where the channel estimation process is initialized by subspace method with lower pilot length.Finally,the simulation results show that a stable cluster formation is established by our proposed coalition game method and it outperforms compared with full coordinated schemes.
文摘This study investigated the characteristics and formation of the online social trust network of Epinions.com, a general consumer review site. An analysis of the static structure of this social trust network revealed a high clustering coefficient, short average path length, and power-law degree distribution;it is therefore a small-world and scale-free trust network. The dynamic evolutionary characteristics of the online social network (OSN) were also examined. The results showed that the scale of the network followed a sigmoidal curve;the average degree of the network was nonconstant and changed into a bell-shaped distribution;the density of the network decreased and subsequently stabilized;and user trust diffusion in the network conformed to the Bass model. Finally, the formation of trust within the network was researched at the overall network (macro) and individual user (micro) levels. Compared with their accumulated contribution and reputation, user activeness had a larger effect on trust formation in OSNs, indicating a “diminishing returns” phenomenon. This phenomenon contrasts with the Matthew effect (i.e. , the more reputation a person has, the more likely he or she is to be trusted) in real-world social networks.
基金supported by the National Natural Science Foundation of China(Nos.22305169 and 22271211)the Youth Natural Science Foundation of Shanxi Province(No.202403021212028)the 1331 Project of Shanxi Province.
文摘Significant advancements have been made in metal-organic frameworks(MOFs)for proton conductivity in proton exchange membrane fuel cells;however,a comprehensive and rational design road map for these materials remains under explored,particularly regarding the quantitative contributions of internal structural factors(proton donor-acceptor types and spatial distances)and external environmental factors(temperature and humidity)to hydrogen-bond formation.In this study,the hydrogen-bonded network formation potential(ФH)is proposed based on these factors to establish structure-property relationship of MOFs via artificial neural network(ANN)model,by which a linear function relationship has been fitted to facilitate the rational design of MOFs,providing a simple assessment of proton conductivity performance in reverse.As a proof of concept,UiO-66-NH_(2)-SO_(3)H with varying group ratios was fabricated,and UiO-66-NH_(2)-SO_(3)H-1:5 exhibited favorable proton conductivity(0.08 S∙cm-1)due to the favorable matching of Brönsted acid-base pairs,which facilitates the extensive formation of hydrogen-bonded networks.The proposed hydrogen-bonded network formation potential is expected to advance the design and synthesis of MOF-based proton-conductive materials,serving as a valuable index for the proton exchange membrane fuel cell research community.
基金co-supported by the National Natural Science Foundation of China(Nos.61633003 and 61522301)Heilongjiang Province Science Foundation for Youths(Nos.QC2012C024 and QC2015064)the Research Fund for Doctoral Program of Higher Education of China(No.20132302110028)
文摘In this paper,attitude coordinated tracking control algorithms for multiple spacecraft formation are investigated with consideration of parametric uncertainties,external disturbances,communication delays and actuator saturation.Initially,a sliding mode delay-dependent attitude coordinated controller is proposed under bounded external disturbances.However,neither inertia uncertainty nor actuator constraint has been taken into account.Then,a robust saturated delaydependent attitude coordinated control law is further derived,where uncertainties and external disturbances are handled by Chebyshev neural networks（CNN）.In addition,command filter technique is introduced to facilitate the backstepping design procedure,through which actuator saturation problem is solved.Thus the spacecraft in the formation are able to track the reference attitude trajectory even in the presence of time-varying communication delays.Rigorous analysis is presented by using Lyapunov-Krasovskii approach to demonstrate the stability of the closed-loop system under both control algorithms.Finally,the numerical examples are carried out to illustrate the efficiency of the theoretical results.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60674037,61074017 and 61074004)the Program for New Century Excellent Talents in Universities (Grant No. NCET-09-0674)the Program for Liaoning Excellent Talents in Universities (Grant No. 2009R06)
文摘This paper is concerned with the formation control problem of multiple underactuated surface vessels moving in a leader-follower formation. The formation is achieved by the follower to track a virtual target defined relative to the leader. A robust adaptive target tracking law is proposed by using neural network and backstepping techniques. The advantage of the proposed control scheme is that the uncertain nonlinear dynamics caused by Coriolis/centripetal forces, nonlinear damping, unmodeled hydrodynamics and disturbances from the environment can be compensated by on line learning. Based on Lyapunov analysis, the proposed controller guarantees the tracking errors converge to a small neighborhood of the origin. Simulation results demonstrate the effectiveness of the control strategy.
基金Supported by Bidding Project of Henan Tobacco CompanyKey Scientific and Technological Project of Henan Tobacco CompanyStudy on Development and Support System of Tobacco Family Farms in the Context of Base Unit(H YKJ201413)
文摘Family farm is an essential modern agricultural micro economic organization. With accelerated advance of rural land circulation and large-scale management,family farm gradually becomes an important choice for modern agricultural management. With ANT as theoretical basis,this paper analyzed formation of family farms in the joint action of endogenous and exogenous forces. Besides,it analyzed Fengsheng Tobacco Family Farm of Guyue Town in Zhucheng City of Shandong Province and Li Chunfeng's Family Farm in Songjiang District of Shanghai.Research indicates that different regional environments bring about different actors and also different formation paths for family farms.
文摘Learning from the conventional practice of network IP address format, this paper proposed an IP-format-based algorithm for ZigBee energy-balanced routing protocol optimization. The algorithm combines node’s cluster address and node’s network short address into a new address and divides the address’s field as IP-format. So that the address will contain information of the network’s topology and provide decision base for a routing algorithm to optimize the original algorithm selection criteria. Meanwhile, in order to improve the ratio of valid data packets and reduce routing overhead, the new algorithm controls the general direction and the number of hops of the RREQ packets to reduce unwarranted data packet transmission. Finally, the simulation carried out on NS platform demonstrates the algorithm’s superiority on network’s delay jitter, overhead and residual energy.
基金National Natural Science foundations of China(Nos.61032004,91338201,and 61231011)National High Technology Research and Development Program of China(863 Program)(No.2012AA121605)
文摘The ability of the monolithic satellite,satellite orbit(especially GEO),and radio resource are very limited,so the development of distributed satellite cluster network(DSCN) receives more and more worldwide attention.In this paper,DSCN is surveyed and the study status of DSCN architecture design is summarized.The formation flying of spacecrafts,reconfiguration,networking,and applied research on distributed satellite spacecraft are described in detail.The DSCN will provide a great technology innovation for space information network,satellite communications,satellite navigation,deep space exploration,and space remote sensing.In addition,this paper points out future trends of the DSCN development.
文摘After long-term waterflooding in unconsolidated sandstone reservoir, the high-permeability channels are easy to evolve, which leads to a significant reduction in water flooding efficiency and a poor oilfield development effect. The current researches on the formation parameters variation are mainly based on the experiment analysis or field statistics, while lacking quantitative research of combining microcosmic and macroscopic mechanism. A network model was built after taking the detachment and entrapment mechanisms of particles in unconsolidated sandstone reservoir into consideration. Then a coupled mathematical model for the formation parameters variation was established based on the network modeling and the model of fluids flowing in porous media. The model was solved by a finite-difference method and the Gauss-Seidel iterative technique. A novel field-scale reservoir numerical simulator was written in Fortran 90 and it can be used to predict 1) the evolvement of high-permeability channels caused by particles release and migration in the long-term water flooding process, and 2) well production performances and remaining oil distribution. In addition, a series of oil field examples with inverted nine-spot pattern was made on the new numerical simulator. The results show that the high-permeability channels are more likely to develop along the main streamlines between the injection and production wells, and the formation parameters variation has an obvious influence on the remaining oil distribution.
