A robust dissipative control problem for a class of It-type stochastic systems is discussed with Markovian jumping parameters and time-varying delay. A memoryless state feedback dissipative controller is developed bas...A robust dissipative control problem for a class of It-type stochastic systems is discussed with Markovian jumping parameters and time-varying delay. A memoryless state feedback dissipative controller is developed based on Lyapunov-Krasovskii functional approach such that the closed-loop system is robustly stochastically stable and weakly delay-dependent （RSSWDD） and strictly （Q, S, R）-dissipative. The sufficient condition on the existence of state feedback dissipative controller is presented by linear matrix inequality （LMI）. And the desired controller can be concluded as solving a set of LMI. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed approach.展开更多
This paper focused on a class of linear state-delayed systems with or without uncertainty. As for uncertain systems, dissipative uncertainty description contains norm-bounded and positive real uncertainties as special...This paper focused on a class of linear state-delayed systems with or without uncertainty. As for uncertain systems, dissipative uncertainty description contains norm-bounded and positive real uncertainties as special cases. The paper is concerned with the design of dissipative static state feedback controllers such that the closed-loop system is (robustly) asymptotically stable and strictly (Q,S,R)-dissipative. Sufficient conditions for the existence of the quadratic dissipative state feedback controllers are obtained by using a linear matrix inequality (LMI) approach. It is shown that the solvability of dissipative controller design problem is implied by the feasibility of LMIs. The main results of this paper unify the existing results on H ∞ control and passive control.展开更多
Based on the quadratic supply rate, the problem of robust dissipative control for a class of uncertain nonlinear system with sector nonlinear input is discussed. The uncertainty is described by bounded norm. It is sho...Based on the quadratic supply rate, the problem of robust dissipative control for a class of uncertain nonlinear system with sector nonlinear input is discussed. The uncertainty is described by bounded norm. It is shown that the robust dissipative control problem can be resolved for all admissible uncertainty, if there exists a storage function such that Hamilton Jacobi inequality holds. When the uncertainties of the system satisfy the matching condition, and input function within the boundedness of the sector, the closed loop system will be stronger dissipativeness, and the controller which we obtained in the paper is more flexible, because it contains an adjustable parameter for some certain range.展开更多
In this note, the dissipative control problem of the general quadratic supply rate for state delayed systems is considered. A systematic approach is used in this work so that a sufficient condition on the existence of...In this note, the dissipative control problem of the general quadratic supply rate for state delayed systems is considered. A systematic approach is used in this work so that a sufficient condition on the existence of a delay-independent state feedback controller is given. In addition, a sufficient condition on the existence of a delay-dependent state feedback is presented. Our solutions are expressed in terms of matrix inequalities that can be solved by numerical method. The delay-dependent controller might be less conservative than the delay-independent one in the sense that the delay-dependent case may have a solution for a larger class of systems than that for delay-independent case.展开更多
Longitudinal seismic performance is a critical aspect to be considered during the tunnel design process,in addition to cross-sectional considerations.The present study proposed using a laminated shear energy dissipati...Longitudinal seismic performance is a critical aspect to be considered during the tunnel design process,in addition to cross-sectional considerations.The present study proposed using a laminated shear energy dissipation(LSED)structure to achieve effective longitudinal seismic design.The proposed structure consists of thin steel plates and alternately bonded layers of rubber,which can be installed around the periphery of the secondary lining.This configuration guarantees that the tunnels will exhibit optimal axial deformation capacity and robust rigid resistance to circumferential compression from the surrounding rock.To evaluate the impact of the LSED structure on the longitudinal seismic performance of the tunnel,a fine numerical model of the LSED structureetunnel liningesurrounding rock system was developed using finite element simulation.The evaluation criteria include maximum principal stress and strain energy.The seismic response of the tunnel with the LSED structure exhibited a notable reduction of over 40%in terms of seismic attenuation rate when subjected to the Trinidad seismic wave compared to the tunnel without the LSED structure.Furthermore,the aseismic mechanism of the proposed LSED structure is discussed,considering both internal factors such as the rubber shear modulus,steel plate dimensions,and number and location of structures,and external influencing factors such as seismic wave parameters and surrounding rock quality.Meanwhile,the effectiveness of the tunnel with the LSED structure has been quantitatively demonstrated in terms of seismic fragility curves.展开更多
China is a country where 100% of the territory is located in a seismic zone. Most of the strong earthquakes are over prediction. Most fatalities are caused by structural collapse. Earthquakes not only cause severe dam...China is a country where 100% of the territory is located in a seismic zone. Most of the strong earthquakes are over prediction. Most fatalities are caused by structural collapse. Earthquakes not only cause severe damage to structures, but can also damage non-structural elements on and inside of facilities. This can halt city life, and disrupt hospitals, airports, bridges, power plants, and other infrastructure. Designers need to use new techniques to protect structures and facilities inside. Isolation, energy dissipation and, control systems are more and more widely used in recent years in China. Currently, there are nearly 6,500 structures with isolation and about 3,000 structures with passive energy dissipation or hybrid control in China. The mitigation techniques are applied to structures like residential buildings, large or complex structures, bridges, underwater tunnels, historical or cultural relic sites, and industrial facilities, and are used for retrofitting of existed structures. This paper introduces design rules and some new and innovative devices for seismic isolation, energy dissipation and hybrid control for civil and industrial structures. This paper also discusses the development trends for seismic resistance, seismic isolation, passive and active control techniques for the future in China and in the world.展开更多
In order to eliminate the energy waste caused by the traditional static hardware multithreaded processor used in real-time embedded system working in the low workload situation, the energy efficiency of the hardware m...In order to eliminate the energy waste caused by the traditional static hardware multithreaded processor used in real-time embedded system working in the low workload situation, the energy efficiency of the hardware multithread is discussed and a novel dynamic multithreaded architecture is proposed. The proposed architecture saves the energy wasted by removing idle threads without manipulation on the original architecture, fulfills a seamless switching mechanism which protects active threads and avoids pipeline stall during power mode switching. The report of an implemented dynamic multithreaded processor with 45 nm process from synthesis tool indicates that the area of dynamic multithreaded architecture is only 2.27% higher than the static one in achieving dynamic power dissipation, and consumes 1.3% more power in the same peak performance.展开更多
This paper presents the development and testing of a novel internal dissipation connection for the use of post-tensioned rocking columns.The solution is one of the many referring to the dissipative controlled rocking(...This paper presents the development and testing of a novel internal dissipation connection for the use of post-tensioned rocking columns.The solution is one of the many referring to the dissipative controlled rocking(DCR)bridge design philosophy.The internal dissipaters are carefully designed to be cost-effective and reduce the over-all construction cost.The dissipaters are fully threaded,Grade 300 bars connected to the permanent column and foundation longitudinal reinforcement with threaded couplers.In this research,a DCR column is subjected to subsequent earthquake events,and the dissipaters’strain design limits are chosen such that there is no need for replacing after a significant seismic event.The result is a recommended design strain limit of 1.5%for the dissi-paters that guarantees the structural integrity of the DCR column after a seismic event.Additionally,a cumulated strain of 5%is recommended for the dissipaters before replacement is suggested.The proposed connection de-tailing with replaceable internal dissipaters,combined with post-tensioned high strength bars and well-confined concrete,provided self-centring capabilities(no residual displacement),dissipation capacity and significantly less damage in the bridge column than a traditional reinforced concrete solution.展开更多
Based on the weighted residual method,a single-step time integration algorithm with higher-order accuracy and unconditional stability has been proposed,which is superior to the second-order accurate algorithms in trac...Based on the weighted residual method,a single-step time integration algorithm with higher-order accuracy and unconditional stability has been proposed,which is superior to the second-order accurate algorithms in tracking long-term dynamics.For improving such a higher-order accurate algorithm,this paper proposes a two sub-step higher-order algorithm with unconditional stability and controllable dissipation.In the proposed algorithm,a time step interval[t_(k),t_(k)+h]where h stands for the size of a time step is divided into two sub-steps[t_(k),t_(k)+γh]and[t_(k)+γh,t_(k)+h].A non-dissipative fourth-order algorithm is used in the rst sub-step to ensure low-frequency accuracy and a dissipative third-order algorithm is employed in the second sub-step to lter out the contribution of high-frequency modes.Besides,two approaches are used to design the algorithm parameterγ.The rst approach determinesγby maximizing low-frequency accuracy and the other determinesγfor quickly damping out highfrequency modes.The present algorithm usesρ_(∞)to exactly control the degree of numerical dissipation,and it is third-order accurate when 0≤ρ_(∞)<1 and fourth-order accurate whenρ_(∞)=1.Furthermore,the proposed algorithm is self-starting and easy to implement.Some illustrative linear and nonlinear examples are solved to check the performances of the proposed two sub-step higher-order algorithm.展开更多
基金supported in part by the National Natural Science Foundation of China (60874045 60904030)+1 种基金the Foundation of the Education Bureau of Jiangsu Province (09KJB510019)the Natural Science Foundation of Jiangsu Province (BK2009184)
文摘A robust dissipative control problem for a class of It-type stochastic systems is discussed with Markovian jumping parameters and time-varying delay. A memoryless state feedback dissipative controller is developed based on Lyapunov-Krasovskii functional approach such that the closed-loop system is robustly stochastically stable and weakly delay-dependent （RSSWDD） and strictly （Q, S, R）-dissipative. The sufficient condition on the existence of state feedback dissipative controller is presented by linear matrix inequality （LMI）. And the desired controller can be concluded as solving a set of LMI. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed approach.
文摘This paper focused on a class of linear state-delayed systems with or without uncertainty. As for uncertain systems, dissipative uncertainty description contains norm-bounded and positive real uncertainties as special cases. The paper is concerned with the design of dissipative static state feedback controllers such that the closed-loop system is (robustly) asymptotically stable and strictly (Q,S,R)-dissipative. Sufficient conditions for the existence of the quadratic dissipative state feedback controllers are obtained by using a linear matrix inequality (LMI) approach. It is shown that the solvability of dissipative controller design problem is implied by the feasibility of LMIs. The main results of this paper unify the existing results on H ∞ control and passive control.
基金the National Natural Science Foundation of China(6987401569934030)and Foundation of the Education Department of Hubei Province(99A121)
文摘Based on the quadratic supply rate, the problem of robust dissipative control for a class of uncertain nonlinear system with sector nonlinear input is discussed. The uncertainty is described by bounded norm. It is shown that the robust dissipative control problem can be resolved for all admissible uncertainty, if there exists a storage function such that Hamilton Jacobi inequality holds. When the uncertainties of the system satisfy the matching condition, and input function within the boundedness of the sector, the closed loop system will be stronger dissipativeness, and the controller which we obtained in the paper is more flexible, because it contains an adjustable parameter for some certain range.
文摘In this note, the dissipative control problem of the general quadratic supply rate for state delayed systems is considered. A systematic approach is used in this work so that a sufficient condition on the existence of a delay-independent state feedback controller is given. In addition, a sufficient condition on the existence of a delay-dependent state feedback is presented. Our solutions are expressed in terms of matrix inequalities that can be solved by numerical method. The delay-dependent controller might be less conservative than the delay-independent one in the sense that the delay-dependent case may have a solution for a larger class of systems than that for delay-independent case.
基金supported by the National Natural Science Foundation of China(Grant No.52109132)the Shandong Provincial Natural Science Foundation(Grant No.ZR2020QE270).
文摘Longitudinal seismic performance is a critical aspect to be considered during the tunnel design process,in addition to cross-sectional considerations.The present study proposed using a laminated shear energy dissipation(LSED)structure to achieve effective longitudinal seismic design.The proposed structure consists of thin steel plates and alternately bonded layers of rubber,which can be installed around the periphery of the secondary lining.This configuration guarantees that the tunnels will exhibit optimal axial deformation capacity and robust rigid resistance to circumferential compression from the surrounding rock.To evaluate the impact of the LSED structure on the longitudinal seismic performance of the tunnel,a fine numerical model of the LSED structureetunnel liningesurrounding rock system was developed using finite element simulation.The evaluation criteria include maximum principal stress and strain energy.The seismic response of the tunnel with the LSED structure exhibited a notable reduction of over 40%in terms of seismic attenuation rate when subjected to the Trinidad seismic wave compared to the tunnel without the LSED structure.Furthermore,the aseismic mechanism of the proposed LSED structure is discussed,considering both internal factors such as the rubber shear modulus,steel plate dimensions,and number and location of structures,and external influencing factors such as seismic wave parameters and surrounding rock quality.Meanwhile,the effectiveness of the tunnel with the LSED structure has been quantitatively demonstrated in terms of seismic fragility curves.
文摘China is a country where 100% of the territory is located in a seismic zone. Most of the strong earthquakes are over prediction. Most fatalities are caused by structural collapse. Earthquakes not only cause severe damage to structures, but can also damage non-structural elements on and inside of facilities. This can halt city life, and disrupt hospitals, airports, bridges, power plants, and other infrastructure. Designers need to use new techniques to protect structures and facilities inside. Isolation, energy dissipation and, control systems are more and more widely used in recent years in China. Currently, there are nearly 6,500 structures with isolation and about 3,000 structures with passive energy dissipation or hybrid control in China. The mitigation techniques are applied to structures like residential buildings, large or complex structures, bridges, underwater tunnels, historical or cultural relic sites, and industrial facilities, and are used for retrofitting of existed structures. This paper introduces design rules and some new and innovative devices for seismic isolation, energy dissipation and hybrid control for civil and industrial structures. This paper also discusses the development trends for seismic resistance, seismic isolation, passive and active control techniques for the future in China and in the world.
基金supported partially by the National High Technical Research and Development Program of China (863 Program) under Grants No. 2011AA040101, No. 2008AA01Z134the National Natural Science Foundation of China under Grants No. 61003251, No. 61172049, No. 61173150+2 种基金the Doctoral Fund of Ministry of Education of China under Grant No. 20100006110015Beijing Municipal Natural Science Foundation under Grant No. Z111100054011078the 2012 Ladder Plan Project of Beijing Key Laboratory of Knowledge Engineering for Materials Science under Grant No. Z121101002812005
文摘In order to eliminate the energy waste caused by the traditional static hardware multithreaded processor used in real-time embedded system working in the low workload situation, the energy efficiency of the hardware multithread is discussed and a novel dynamic multithreaded architecture is proposed. The proposed architecture saves the energy wasted by removing idle threads without manipulation on the original architecture, fulfills a seamless switching mechanism which protects active threads and avoids pipeline stall during power mode switching. The report of an implemented dynamic multithreaded processor with 45 nm process from synthesis tool indicates that the area of dynamic multithreaded architecture is only 2.27% higher than the static one in achieving dynamic power dissipation, and consumes 1.3% more power in the same peak performance.
文摘This paper presents the development and testing of a novel internal dissipation connection for the use of post-tensioned rocking columns.The solution is one of the many referring to the dissipative controlled rocking(DCR)bridge design philosophy.The internal dissipaters are carefully designed to be cost-effective and reduce the over-all construction cost.The dissipaters are fully threaded,Grade 300 bars connected to the permanent column and foundation longitudinal reinforcement with threaded couplers.In this research,a DCR column is subjected to subsequent earthquake events,and the dissipaters’strain design limits are chosen such that there is no need for replacing after a significant seismic event.The result is a recommended design strain limit of 1.5%for the dissi-paters that guarantees the structural integrity of the DCR column after a seismic event.Additionally,a cumulated strain of 5%is recommended for the dissipaters before replacement is suggested.The proposed connection de-tailing with replaceable internal dissipaters,combined with post-tensioned high strength bars and well-confined concrete,provided self-centring capabilities(no residual displacement),dissipation capacity and significantly less damage in the bridge column than a traditional reinforced concrete solution.
基金supported by the National Natural Science Foundation of China(Grant Numbers 11872090,11672019,11472035).
文摘Based on the weighted residual method,a single-step time integration algorithm with higher-order accuracy and unconditional stability has been proposed,which is superior to the second-order accurate algorithms in tracking long-term dynamics.For improving such a higher-order accurate algorithm,this paper proposes a two sub-step higher-order algorithm with unconditional stability and controllable dissipation.In the proposed algorithm,a time step interval[t_(k),t_(k)+h]where h stands for the size of a time step is divided into two sub-steps[t_(k),t_(k)+γh]and[t_(k)+γh,t_(k)+h].A non-dissipative fourth-order algorithm is used in the rst sub-step to ensure low-frequency accuracy and a dissipative third-order algorithm is employed in the second sub-step to lter out the contribution of high-frequency modes.Besides,two approaches are used to design the algorithm parameterγ.The rst approach determinesγby maximizing low-frequency accuracy and the other determinesγfor quickly damping out highfrequency modes.The present algorithm usesρ_(∞)to exactly control the degree of numerical dissipation,and it is third-order accurate when 0≤ρ_(∞)<1 and fourth-order accurate whenρ_(∞)=1.Furthermore,the proposed algorithm is self-starting and easy to implement.Some illustrative linear and nonlinear examples are solved to check the performances of the proposed two sub-step higher-order algorithm.
