The discrete time model for a single link of Diffserv is considered in this paper. A novel algorithm is proposed to improve the robustness of the existing model. It allows the link price to fluctuate slightly around t...The discrete time model for a single link of Diffserv is considered in this paper. A novel algorithm is proposed to improve the robustness of the existing model. It allows the link price to fluctuate slightly around the equilibrium price. Simulations are performed to verify the effectiveness of the algorithm. This model solves the problem that the existing model can converge only under the strict condition.展开更多
The formal modelling and verification method has become an effective way of improving the reliability and correctness of complex,safety-critical embedded systems.Statecharts are widely used to formally model embedded ...The formal modelling and verification method has become an effective way of improving the reliability and correctness of complex,safety-critical embedded systems.Statecharts are widely used to formally model embedded applications,but they do not realise the reasonable separation of system concerns,which would result in code scattering and tangling.Aspect-Oriented Software Development(AOSD)technology could separate crosscutting concerns from core concerns and identify potential problems in the early phase of the software development life cycle.Therefore,the paper proposes aspect-oriented timed statecharts(extended timed statecharts with AOSD)to separately model base functional requirements and other requirements(e.g.,scheduling,error handling),thereby improving the modularity and development efficiency of embedded systems.Furthermore,the dynamic behaviours of embedded systems are simulated and analysed to determine whether the model satisfies certain properties(e.g.,liveness,safety)described by computation tree logic formulae.Finally,a given case demonstrates some desired properties processed with respect to the aspect-oriented timed statecharts model.展开更多
High-accuracy motion trajectory tracking control of a pneumatic cylinder driven by a proportional directional control valve was considered. A mathematical model of the system was developed firstly. Due to the time-var...High-accuracy motion trajectory tracking control of a pneumatic cylinder driven by a proportional directional control valve was considered. A mathematical model of the system was developed firstly. Due to the time-varying friction force in the cylinder, unmodeled dynamics, and unknown disturbances, there exist large extent of parametric uncertainties and rather severe uncertain nonlinearities in the pneumatic system. To deal with these uncertainties effectively, an adaptive robust controller was constructed in this work. The proposed controller employs on-line recursive least squares estimation(RLSE) to reduce the extent of parametric uncertainties, and utilizes the sliding mode control method to attenuate the effects of parameter estimation errors, unmodeled dynamics and disturbances. Therefore, a prescribed motion tracking transient performance and final tracking accuracy can be guaranteed. Since the system model uncertainties are unmatched, the recursive backstepping design technology was applied. In order to solve the conflicts between the sliding mode control design and the adaptive control design, the projection mapping was used to condition the RLSE algorithm so that the parameter estimates are kept within a known bounded convex set. Extensive experimental results were presented to illustrate the excellent achievable performance of the proposed controller and performance robustness to the load variation and sudden disturbance.展开更多
A constructive method was presented to design a global robust and adaptive output feedback controller for dynamic positioning of surface ships under environmental disturbances induced by waves, wind, and ocean current...A constructive method was presented to design a global robust and adaptive output feedback controller for dynamic positioning of surface ships under environmental disturbances induced by waves, wind, and ocean currents. The ship's parameters were not required to be known. An adaptive observer was first designed to estimate the ship's velocities and parameters. The ship position measurements were also passed through the adaptive observer to reduce high frequency measurement noise from entering the control system. Using these estimate signals, the control was then designed based on Lyapunov's direct method to force the ship's position and orientation to globally asymptotically converge to desired values. Simulation results illustrate the effectiveness of the proposed control system. In conclusion, the paper presented a new method to design an effective control system for dynamic positioning of surface ships.展开更多
The low-cost,self-configuration capability and "plug-and-play" feature of Ethernet establishes its dominant position in the local area networks(LAN).However,it is hard to extend to large scale because of the...The low-cost,self-configuration capability and "plug-and-play" feature of Ethernet establishes its dominant position in the local area networks(LAN).However,it is hard to extend to large scale because of the legacy broadcast-based service discovery mechanism.Therefore,to solve this problem,a new split network architecture named Software-Defined Networking(SDN) is introduced in this paper,and a novel floodless service discovery mechanism(FSDM)for SDN is designed.For the FSDM,the widespread broadcast messages for Dynamic Host Configuration Protocol(DHCP) and Address Resolution Protocol(ARP) are considered especially,respectively.Then the DHCP relay and ARP proxy are proposed to handle DHCP broadcast messages and ARP broadcast messages,respectively.The proposed FSDM in this paper can eliminate flooding completely,reserve the autoconfiguration characteristics.Particularly,there is no need to change the existing hardware,software and protocols of hosts for the proposed scheme.Finally,the simulation results are demonstrated to show that our proposed model allows redundant links existed in network and has the property of scalability,which can significantly reduce network traffic in data plane and control traffic in control plane,and decrease the overhead of control plane.展开更多
The paper presents general description of combined structural system and initial analysis of an innovative system proposed as the main support structure for tall or heavy loaded buildings located on subsoil of very sm...The paper presents general description of combined structural system and initial analysis of an innovative system proposed as the main support structure for tall or heavy loaded buildings located on subsoil of very small load-carrying ability or in earthquake areas. Moreover there is presented also an innovative two-stage method of the approximate calculation of the statically indeterminate trusses. Both are invented by the author by application of the principles of the superposition method.展开更多
This paper presents some new dynamic interaction analysis approaches for square or non-square systems and a pairing evaluation method. For square stable systems, an open-loop approach is proposed, which features the t...This paper presents some new dynamic interaction analysis approaches for square or non-square systems and a pairing evaluation method. For square stable systems, an open-loop approach is proposed, which features the tradeoff between the contributions of response time constant and delay time to relative gain. For non-square stable systems, an extension from the proposed open-loop approach for square systems is presented and the corresponding pairing procedure is given. No interaction analysis approach is perfect for all systems, so any recommended pairing needs to be examined. An evaluation method is proposed in closed-loop with optimal controllers for each loop and whether the pairing is appropriate can be evaluated through testing if the equivalent relative gain is within defined scope. The advantages and effectiveness of proposed interaction analysis approaches and pairing evaluation method are highlighted via several examples of industrial processes.展开更多
This paper investigates a consensus design problem for continuous-time first-order multiagent systems with uniform constant communication delay.Provided that the agent dynamic is unstable and the diagraph is undirecte...This paper investigates a consensus design problem for continuous-time first-order multiagent systems with uniform constant communication delay.Provided that the agent dynamic is unstable and the diagraph is undirected,sufficient conditions are derived to guarantee consensus.The key technique is the adoption of historical input information in the protocol.Especially,when agent's own historical input information is used in the protocol design,the consensus condition is constructed in terms of agent dynamic,communication delay,and the eigenratio of the network topology.Simulation result is presented to validate the effectiveness of the theoretical result.展开更多
In generalized linear models with fixed design, under the assumption λ↑_n→∞ and other regularity conditions, the asymptotic normality of maximum quasi-likelihood estimator ^↑βn, which is the root of the quasi-li...In generalized linear models with fixed design, under the assumption λ↑_n→∞ and other regularity conditions, the asymptotic normality of maximum quasi-likelihood estimator ^↑βn, which is the root of the quasi-likelihood equation with natural link function ∑i=1^n Xi（yi -μ（Xi′β）） = 0, is obtained, where λ↑_n denotes the minimum eigenvalue of ∑i=1^nXiXi′, Xi are bounded p × q regressors, and yi are q × 1 responses.展开更多
文摘The discrete time model for a single link of Diffserv is considered in this paper. A novel algorithm is proposed to improve the robustness of the existing model. It allows the link price to fluctuate slightly around the equilibrium price. Simulations are performed to verify the effectiveness of the algorithm. This model solves the problem that the existing model can converge only under the strict condition.
基金supported by the National Natural Science Foundation of China under GrantsNo.61173048,No.61103115
文摘The formal modelling and verification method has become an effective way of improving the reliability and correctness of complex,safety-critical embedded systems.Statecharts are widely used to formally model embedded applications,but they do not realise the reasonable separation of system concerns,which would result in code scattering and tangling.Aspect-Oriented Software Development(AOSD)technology could separate crosscutting concerns from core concerns and identify potential problems in the early phase of the software development life cycle.Therefore,the paper proposes aspect-oriented timed statecharts(extended timed statecharts with AOSD)to separately model base functional requirements and other requirements(e.g.,scheduling,error handling),thereby improving the modularity and development efficiency of embedded systems.Furthermore,the dynamic behaviours of embedded systems are simulated and analysed to determine whether the model satisfies certain properties(e.g.,liveness,safety)described by computation tree logic formulae.Finally,a given case demonstrates some desired properties processed with respect to the aspect-oriented timed statecharts model.
基金Projects(50775200,50905156)supported by the National Natural Science Foundation of China
文摘High-accuracy motion trajectory tracking control of a pneumatic cylinder driven by a proportional directional control valve was considered. A mathematical model of the system was developed firstly. Due to the time-varying friction force in the cylinder, unmodeled dynamics, and unknown disturbances, there exist large extent of parametric uncertainties and rather severe uncertain nonlinearities in the pneumatic system. To deal with these uncertainties effectively, an adaptive robust controller was constructed in this work. The proposed controller employs on-line recursive least squares estimation(RLSE) to reduce the extent of parametric uncertainties, and utilizes the sliding mode control method to attenuate the effects of parameter estimation errors, unmodeled dynamics and disturbances. Therefore, a prescribed motion tracking transient performance and final tracking accuracy can be guaranteed. Since the system model uncertainties are unmatched, the recursive backstepping design technology was applied. In order to solve the conflicts between the sliding mode control design and the adaptive control design, the projection mapping was used to condition the RLSE algorithm so that the parameter estimates are kept within a known bounded convex set. Extensive experimental results were presented to illustrate the excellent achievable performance of the proposed controller and performance robustness to the load variation and sudden disturbance.
文摘A constructive method was presented to design a global robust and adaptive output feedback controller for dynamic positioning of surface ships under environmental disturbances induced by waves, wind, and ocean currents. The ship's parameters were not required to be known. An adaptive observer was first designed to estimate the ship's velocities and parameters. The ship position measurements were also passed through the adaptive observer to reduce high frequency measurement noise from entering the control system. Using these estimate signals, the control was then designed based on Lyapunov's direct method to force the ship's position and orientation to globally asymptotically converge to desired values. Simulation results illustrate the effectiveness of the proposed control system. In conclusion, the paper presented a new method to design an effective control system for dynamic positioning of surface ships.
基金supported by the National Basic Research Program(973)of China(No.2012CB315801)the National Natural Science Fund(No.61302089,61300184)the fundamental research funds for the Central Universities(No.2013RC0113)
文摘The low-cost,self-configuration capability and "plug-and-play" feature of Ethernet establishes its dominant position in the local area networks(LAN).However,it is hard to extend to large scale because of the legacy broadcast-based service discovery mechanism.Therefore,to solve this problem,a new split network architecture named Software-Defined Networking(SDN) is introduced in this paper,and a novel floodless service discovery mechanism(FSDM)for SDN is designed.For the FSDM,the widespread broadcast messages for Dynamic Host Configuration Protocol(DHCP) and Address Resolution Protocol(ARP) are considered especially,respectively.Then the DHCP relay and ARP proxy are proposed to handle DHCP broadcast messages and ARP broadcast messages,respectively.The proposed FSDM in this paper can eliminate flooding completely,reserve the autoconfiguration characteristics.Particularly,there is no need to change the existing hardware,software and protocols of hosts for the proposed scheme.Finally,the simulation results are demonstrated to show that our proposed model allows redundant links existed in network and has the property of scalability,which can significantly reduce network traffic in data plane and control traffic in control plane,and decrease the overhead of control plane.
文摘The paper presents general description of combined structural system and initial analysis of an innovative system proposed as the main support structure for tall or heavy loaded buildings located on subsoil of very small load-carrying ability or in earthquake areas. Moreover there is presented also an innovative two-stage method of the approximate calculation of the statically indeterminate trusses. Both are invented by the author by application of the principles of the superposition method.
基金Supported by the National Natural Science Foundation of China(21006127)the National Basic Research Program of China(2012CB720500)
文摘This paper presents some new dynamic interaction analysis approaches for square or non-square systems and a pairing evaluation method. For square stable systems, an open-loop approach is proposed, which features the tradeoff between the contributions of response time constant and delay time to relative gain. For non-square stable systems, an extension from the proposed open-loop approach for square systems is presented and the corresponding pairing procedure is given. No interaction analysis approach is perfect for all systems, so any recommended pairing needs to be examined. An evaluation method is proposed in closed-loop with optimal controllers for each loop and whether the pairing is appropriate can be evaluated through testing if the equivalent relative gain is within defined scope. The advantages and effectiveness of proposed interaction analysis approaches and pairing evaluation method are highlighted via several examples of industrial processes.
基金supported by the Taishan Scholar Construction Engineering by Shandong Government,the National Natural Science Foundation of China under Grant Nos.61120106011 and 61203029
文摘This paper investigates a consensus design problem for continuous-time first-order multiagent systems with uniform constant communication delay.Provided that the agent dynamic is unstable and the diagraph is undirected,sufficient conditions are derived to guarantee consensus.The key technique is the adoption of historical input information in the protocol.Especially,when agent's own historical input information is used in the protocol design,the consensus condition is constructed in terms of agent dynamic,communication delay,and the eigenratio of the network topology.Simulation result is presented to validate the effectiveness of the theoretical result.
基金the National Natural Science Foundation of China under Grant Nos.10171094,10571001,and 30572285the Foundation of Nanjing Normal University under Grant No.2005101XGQ2B84+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China under Grant No.07KJD110093the Foundation of Anhui University under Grant No.02203105
文摘In generalized linear models with fixed design, under the assumption λ↑_n→∞ and other regularity conditions, the asymptotic normality of maximum quasi-likelihood estimator ^↑βn, which is the root of the quasi-likelihood equation with natural link function ∑i=1^n Xi（yi -μ（Xi′β）） = 0, is obtained, where λ↑_n denotes the minimum eigenvalue of ∑i=1^nXiXi′, Xi are bounded p × q regressors, and yi are q × 1 responses.
