The Cross River watershed was disturbed by historic logging activity during the past century, but under the management of the USDA （United States Department of Agriculture） Forest Service, the area has mostly recove...The Cross River watershed was disturbed by historic logging activity during the past century, but under the management of the USDA （United States Department of Agriculture） Forest Service, the area has mostly recovered from ecological disturbance. Today a new threat is being imposed by climate change; changes affect not only the temperature but also more extreme wind and rain In 2012, a mega-storm event passed through the north shore region of Lake Superior overwhelming many watersheds with excessive rain and runoff. As part of a Cross River study for the Forest Service, pre- and post-event hydrologic adjustment of the Cross River watershed were captured. Samples were collected for δD and δ18O during April, July, and September to estimate HRT （hydraulic residence time） using the stable isotopes of hydrogen and oxygen, The results showed that water collected throughout the watershed shifted toward the signature of the mega-event precipitation signature, then slowly diffused with new precipitation and fractionation processes that resumed into the summer and fall.展开更多
The authors obtain new characterizations of unconditional Cauchy series in terms of separation properties of subfamilies of p(N), and a generalization of the Orlicz-Pettis Theorem is also obtained. New results on the ...The authors obtain new characterizations of unconditional Cauchy series in terms of separation properties of subfamilies of p(N), and a generalization of the Orlicz-Pettis Theorem is also obtained. New results on the uniform convergence on matrices and a new version of the Hahn-Schur summation theorem are proved. For matrices whose rows define unconditional Cauchy series, a better sufficient condition for the basic Matrix Theorem of Antosik and Swartz, new necessary conditions and a new proof of that theorem are given.展开更多
It is skowed that if the first exit distribution leaving any ball from the center is theuniform distribution on the sphere, then the Levy process is a scaled Brownian motion.The paper also gives a characterization of ...It is skowed that if the first exit distribution leaving any ball from the center is theuniform distribution on the sphere, then the Levy process is a scaled Brownian motion.The paper also gives a characterization of a continuous Hunt process by the first exitdistribution from any ball.展开更多
This paper investigates the controllability problem of time-variant linear stochastic controlsystems.A sufficient and necessary condition is established for stochastic exact controllability,whichprovides a useful alge...This paper investigates the controllability problem of time-variant linear stochastic controlsystems.A sufficient and necessary condition is established for stochastic exact controllability,whichprovides a useful algebraic criterion for stochastic control systems.Furthermore,when the stochasticsystems degenerate to deterministic systems,the algebraic criterion becomes the counterpart for thecomplete controllability of deterministic control systems.展开更多
The authors consider the Cauchy problem with a kind of non-smooth initial data for quasilinear hyperbolic systems and obtain a necessary and sufficient condition to guarantee the existence and uniqueness of global wea...The authors consider the Cauchy problem with a kind of non-smooth initial data for quasilinear hyperbolic systems and obtain a necessary and sufficient condition to guarantee the existence and uniqueness of global weakly discontinuous solution.展开更多
This paper is concerned with stability of a class of randomly switched systems of ordinary differential equations. The system under consideration can be viewed as a two-component process （X（t）, α（t））, where the...This paper is concerned with stability of a class of randomly switched systems of ordinary differential equations. The system under consideration can be viewed as a two-component process （X（t）, α（t））, where the system is linear in X（t） and α（t） is a continuous-time Markov chain with a finite state space. Conditions for almost surely exponential stability and instability are obtained. The conditions are based on the Lyapunov exponent, which in turn, depends on the associate invaxiant density. Concentrating on the case that the continuous component is two dimensional, using transformation techniques, differential equations satisfied by the invariant density associated with the Lyapunov exponent are derived. Conditions for existence and uniqueness of solutions are derived. Then numerical solutions are developed to solve the associated differential equations.展开更多
The stabilization with receding horizon control （RHC） of It5 stochastic time-varying systems is studied in this paper. Based on monotonically non-increasing of optimal cost and stochastic Lyapunov stability theory, ...The stabilization with receding horizon control （RHC） of It5 stochastic time-varying systems is studied in this paper. Based on monotonically non-increasing of optimal cost and stochastic Lyapunov stability theory, a necessary and sufficient stabilization condition on the terminal weighting matrix is proposed, which guarantees the mean-square stability of the closed-loop system. The explicit receding horizon controller is obtained by employing stochastic maximum principle. Simulations demonstrate the effectiveness of the proposed method.展开更多
文摘The Cross River watershed was disturbed by historic logging activity during the past century, but under the management of the USDA （United States Department of Agriculture） Forest Service, the area has mostly recovered from ecological disturbance. Today a new threat is being imposed by climate change; changes affect not only the temperature but also more extreme wind and rain In 2012, a mega-storm event passed through the north shore region of Lake Superior overwhelming many watersheds with excessive rain and runoff. As part of a Cross River study for the Forest Service, pre- and post-event hydrologic adjustment of the Cross River watershed were captured. Samples were collected for δD and δ18O during April, July, and September to estimate HRT （hydraulic residence time） using the stable isotopes of hydrogen and oxygen, The results showed that water collected throughout the watershed shifted toward the signature of the mega-event precipitation signature, then slowly diffused with new precipitation and fractionation processes that resumed into the summer and fall.
文摘The authors obtain new characterizations of unconditional Cauchy series in terms of separation properties of subfamilies of p(N), and a generalization of the Orlicz-Pettis Theorem is also obtained. New results on the uniform convergence on matrices and a new version of the Hahn-Schur summation theorem are proved. For matrices whose rows define unconditional Cauchy series, a better sufficient condition for the basic Matrix Theorem of Antosik and Swartz, new necessary conditions and a new proof of that theorem are given.
基金Project supported by the National Natural Science Foundation of China (No.10271109)
文摘It is skowed that if the first exit distribution leaving any ball from the center is theuniform distribution on the sphere, then the Levy process is a scaled Brownian motion.The paper also gives a characterization of a continuous Hunt process by the first exitdistribution from any ball.
基金supported by the National Natural Science Foundation under Grant Nos.60904029 and 60704002the State Key Laboratory under Grant No.RCS2008ZT002
文摘This paper investigates the controllability problem of time-variant linear stochastic controlsystems.A sufficient and necessary condition is established for stochastic exact controllability,whichprovides a useful algebraic criterion for stochastic control systems.Furthermore,when the stochasticsystems degenerate to deterministic systems,the algebraic criterion becomes the counterpart for thecomplete controllability of deterministic control systems.
基金Project supported by the Special Funds for Major State Basic Research Projects of China
文摘The authors consider the Cauchy problem with a kind of non-smooth initial data for quasilinear hyperbolic systems and obtain a necessary and sufficient condition to guarantee the existence and uniqueness of global weakly discontinuous solution.
基金This research was supported in part by the National Science Foundation under Grant No. DMS-0907753, in part by the Air Force Office of Scientific Research under Grant No. FA9550-10-1-0210, and in part by the National Natural Science Foundation of China under Grant No. 70871055.
文摘This paper is concerned with stability of a class of randomly switched systems of ordinary differential equations. The system under consideration can be viewed as a two-component process （X（t）, α（t））, where the system is linear in X（t） and α（t） is a continuous-time Markov chain with a finite state space. Conditions for almost surely exponential stability and instability are obtained. The conditions are based on the Lyapunov exponent, which in turn, depends on the associate invaxiant density. Concentrating on the case that the continuous component is two dimensional, using transformation techniques, differential equations satisfied by the invariant density associated with the Lyapunov exponent are derived. Conditions for existence and uniqueness of solutions are derived. Then numerical solutions are developed to solve the associated differential equations.
基金supported by the Taishan Scholar Construction Engineering by Shandong Governmentthe National Natural Science Foundation of China under Grant Nos.61120106011 and 61573221
文摘The stabilization with receding horizon control （RHC） of It5 stochastic time-varying systems is studied in this paper. Based on monotonically non-increasing of optimal cost and stochastic Lyapunov stability theory, a necessary and sufficient stabilization condition on the terminal weighting matrix is proposed, which guarantees the mean-square stability of the closed-loop system. The explicit receding horizon controller is obtained by employing stochastic maximum principle. Simulations demonstrate the effectiveness of the proposed method.
