In order to improve the scalability and reliability of Software Defined Networking(SDN),many studies use multiple controllers to constitute logically centralized control plane to provide load balancing and fail over.I...In order to improve the scalability and reliability of Software Defined Networking(SDN),many studies use multiple controllers to constitute logically centralized control plane to provide load balancing and fail over.In this paper,we develop a flexible dormant multi-controller model based on the centralized multi-controller architecture.The dormant multi-controller model allows part of controllers to enter the dormant state under light traffic condition for saving system cost.Meanwhile,through queueing analysis,various performance measures of the system can be obtained.Moreover,we analyze the real traffic of China Education Network and use the results as the parameters of computer simulation and verify the effects of parameters on the system characteristics.Finally,a total expected cost function is established,and genetic algorithm is employed to find the optimal values of various parameters to minimize system cost for the deployment decision making.展开更多
For the uncertain continuous-time systems with input time-delay that widely exist in the production processes, we can get the existent conditions for the guaranteed cost control of these systems by using the Lyapunov ...For the uncertain continuous-time systems with input time-delay that widely exist in the production processes, we can get the existent conditions for the guaranteed cost control of these systems by using the Lyapunov stability theory, linear matrix inequalities theory and quadratic cost criterion. We can achieve the guaranteed cost control of this system by solving a matrix inequality. A state feed back guaranteed cost control law can be constructed by solving certain parameter-dependent Riccati matrix equation.展开更多
The challenges of the ocean working environment and conditions require that marine instrumentsand equipment be highly reliable and environmentally adaptable.The various parts and componentsof marine instruments should...The challenges of the ocean working environment and conditions require that marine instrumentsand equipment be highly reliable and environmentally adaptable.The various parts and componentsof marine instruments should be interchangeable,so as to reduce product costs and reasonably economizethe use of energy and material resources.This paper intruduces the importance of formulating marine instrumentproduct standards,the present conditions and problems of marine product standards,and proposesrelated measures and suggestions to sovle the problems.展开更多
In the paper the proposition of a discrete, robust, minimal energetic P servo controller for second order plant is presented. The plant under consideration is described with the use of a state space equation and a tra...In the paper the proposition of a discrete, robust, minimal energetic P servo controller for second order plant is presented. The plant under consideration is described with the use of a state space equation and a transfer function with interval parameters. The considered model describes for example an oriented PV （photovoltaic） system. As a controller a P （proportional） controller was applied. It is very simple and their application in the situation we deal with assures the suitable control performance. The controller is going to be implemented at digital platform. To construct the control system a cost function proposed by the authors was applied. It describes both the energy consumption and the sample time of controller. The proposed cost function is a function of plant parameters, describing the dynamics of the plant and controller parameters： proportional gain and sample time. For the cost function a simple geometric interpretation can be given： for fixed plant parameters and varying controller parameters it is a surface in the Ra plane. This fact can be applied to assign of optimal controller. Theoretical results were depicted by a numerical example.展开更多
基金the National High-tech R&D Program ("863" Program) of China，the National Science Foundation of China，National Science & Technology Pillar Program of China，the National Science Foundation of China，the Post-Doctoral Funding of China，Tsinghua-Huawei joint research project
文摘In order to improve the scalability and reliability of Software Defined Networking(SDN),many studies use multiple controllers to constitute logically centralized control plane to provide load balancing and fail over.In this paper,we develop a flexible dormant multi-controller model based on the centralized multi-controller architecture.The dormant multi-controller model allows part of controllers to enter the dormant state under light traffic condition for saving system cost.Meanwhile,through queueing analysis,various performance measures of the system can be obtained.Moreover,we analyze the real traffic of China Education Network and use the results as the parameters of computer simulation and verify the effects of parameters on the system characteristics.Finally,a total expected cost function is established,and genetic algorithm is employed to find the optimal values of various parameters to minimize system cost for the deployment decision making.
文摘For the uncertain continuous-time systems with input time-delay that widely exist in the production processes, we can get the existent conditions for the guaranteed cost control of these systems by using the Lyapunov stability theory, linear matrix inequalities theory and quadratic cost criterion. We can achieve the guaranteed cost control of this system by solving a matrix inequality. A state feed back guaranteed cost control law can be constructed by solving certain parameter-dependent Riccati matrix equation.
文摘The challenges of the ocean working environment and conditions require that marine instrumentsand equipment be highly reliable and environmentally adaptable.The various parts and componentsof marine instruments should be interchangeable,so as to reduce product costs and reasonably economizethe use of energy and material resources.This paper intruduces the importance of formulating marine instrumentproduct standards,the present conditions and problems of marine product standards,and proposesrelated measures and suggestions to sovle the problems.
文摘In the paper the proposition of a discrete, robust, minimal energetic P servo controller for second order plant is presented. The plant under consideration is described with the use of a state space equation and a transfer function with interval parameters. The considered model describes for example an oriented PV （photovoltaic） system. As a controller a P （proportional） controller was applied. It is very simple and their application in the situation we deal with assures the suitable control performance. The controller is going to be implemented at digital platform. To construct the control system a cost function proposed by the authors was applied. It describes both the energy consumption and the sample time of controller. The proposed cost function is a function of plant parameters, describing the dynamics of the plant and controller parameters： proportional gain and sample time. For the cost function a simple geometric interpretation can be given： for fixed plant parameters and varying controller parameters it is a surface in the Ra plane. This fact can be applied to assign of optimal controller. Theoretical results were depicted by a numerical example.
