DC component is contained in inverter output voltage due to many reasons such as the zero-point deviation of operational amplifiers and the differences between power switching transistors′ characteristics. For the pa...DC component is contained in inverter output voltage due to many reasons such as the zero-point deviation of operational amplifiers and the differences between power switching transistors′ characteristics. For the parallel inverter system without output isolation transformers, the difference of DC components of the output voltage can cause large DC loop-current among modular inverters. Aiming at this problem, this paper studies several DC loop-current detecting and restraining methods. By digital adjustment with high precision on the DC components of reference sine wave, the DC components of inverter′s output voltage can be adjusted to restrain DC loop-current. Experimental results prove that the DC loop-current detecting and restraining methods have a good performance.展开更多
The robust stabilizating control problem for a class of uncertain nonlinear large-scale systems is discussed. Based on the theory of both input/output (I/O) linearization and decentralized variable structure control (...The robust stabilizating control problem for a class of uncertain nonlinear large-scale systems is discussed. Based on the theory of both input/output (I/O) linearization and decentralized variable structure control (VSC),two-level and decentralized variable structure control laws for this kind of systems are presented respectively,which achieve asymptotically stabilization despite the uncertainties and disturbances. At last,sirnulation of the disturbed two-pendulum system is given to illustrate the feasibility of proposed technique.展开更多
the traditional enterprise transformation, thanks to the Internet is a hot topic in recent years, many companies are testing the waters, but the real success is not much. This article through to the kaiyuan long tail ...the traditional enterprise transformation, thanks to the Internet is a hot topic in recent years, many companies are testing the waters, but the real success is not much. This article through to the kaiyuan long tail economy, crowdsourcing platform, C2B customization model and information system four aspects of the introduction and analysis, trying to traditional enterprise transformation of the Internet, to provide reference.展开更多
Many systems can display a very short, rapid change stage (quasi-discontinuous region) inside a relatively very long and slow change process. A quantitative definition for the 'quasi-discontinuity' in these sy...Many systems can display a very short, rapid change stage (quasi-discontinuous region) inside a relatively very long and slow change process. A quantitative definition for the 'quasi-discontinuity' in these systems has been introduced. With the aid of a simplified model, some extraordinary Feigenbaum constants have been found inside the period-doubling cascades, the relationship between the values of the extraordinary Feigenbaum constants and the quasi-discontinuity of the system has also been reported. The phenomenon has been observed in Pikovsky circuit and Rose-Hindmash model.展开更多
The mobile Intemet industry has exp- erienced dramatic changes as plenty of new applications and business models emerged. This study conducts a qualitative review on the changes through adopting business ecosystem app...The mobile Intemet industry has exp- erienced dramatic changes as plenty of new applications and business models emerged. This study conducts a qualitative review on the changes through adopting business ecosystem approaches. An analytical framework is estab- lished for reviewing the structure of mobile Internet business ecosystem. Then the core value, key actors, and inter-firm relationships of the mobile Internet ecosystem in the past and in the present are compared. It is found that the ecosystem structure has shifted from an MNO-centric model to a polycentric one with highly expanded value sources and di- versified keystone players. Accordingly some suggestions for regulatory policy makers are provided in terms of the roles of mobile Inter- net in social welfare improvement, the call for a convergent regulatory system, and chal- lenges for information security regulation.展开更多
A time-variant consensus tracking control problem for networked planar multi-agent systems with non-holonomic constraints is investigated in this paper. In the time-variant consensus tracking problem, a leader agent i...A time-variant consensus tracking control problem for networked planar multi-agent systems with non-holonomic constraints is investigated in this paper. In the time-variant consensus tracking problem, a leader agent is expected to track a desired reference input, simultaneously, follower agents are expected to maintain a time-variant formation. To solve the time-variant consensus tracking problem of planar multi-agent systems with non-holonomic constraints, a time-variant consensus tracking control strategy is designed on the basis of an unidirectional topology structure. One of main contributions of this paper is the time-variant consensus tracking protocol for general time-variant formations of planar multi-agent systems with non-holonomic constraints, the other main contribution of this paper is an active predictive control strategy, where predictions of agents are generated actively, so that the computational efficiency is improved than passive approaches. The proposed control strategy is verified by two types of time-varying formations of wheeled mobile robots, and the experimental results show that the proposed control strategy is effective for general time-variant consensus tracking problems of planar multi-agent systems with non-holonomic constraints in local and worldwide networked environments.展开更多
文摘DC component is contained in inverter output voltage due to many reasons such as the zero-point deviation of operational amplifiers and the differences between power switching transistors′ characteristics. For the parallel inverter system without output isolation transformers, the difference of DC components of the output voltage can cause large DC loop-current among modular inverters. Aiming at this problem, this paper studies several DC loop-current detecting and restraining methods. By digital adjustment with high precision on the DC components of reference sine wave, the DC components of inverter′s output voltage can be adjusted to restrain DC loop-current. Experimental results prove that the DC loop-current detecting and restraining methods have a good performance.
文摘The robust stabilizating control problem for a class of uncertain nonlinear large-scale systems is discussed. Based on the theory of both input/output (I/O) linearization and decentralized variable structure control (VSC),two-level and decentralized variable structure control laws for this kind of systems are presented respectively,which achieve asymptotically stabilization despite the uncertainties and disturbances. At last,sirnulation of the disturbed two-pendulum system is given to illustrate the feasibility of proposed technique.
文摘the traditional enterprise transformation, thanks to the Internet is a hot topic in recent years, many companies are testing the waters, but the real success is not much. This article through to the kaiyuan long tail economy, crowdsourcing platform, C2B customization model and information system four aspects of the introduction and analysis, trying to traditional enterprise transformation of the Internet, to provide reference.
文摘Many systems can display a very short, rapid change stage (quasi-discontinuous region) inside a relatively very long and slow change process. A quantitative definition for the 'quasi-discontinuity' in these systems has been introduced. With the aid of a simplified model, some extraordinary Feigenbaum constants have been found inside the period-doubling cascades, the relationship between the values of the extraordinary Feigenbaum constants and the quasi-discontinuity of the system has also been reported. The phenomenon has been observed in Pikovsky circuit and Rose-Hindmash model.
基金supported by the China Fundamental Research Funds for the Central Universities under Grant No.BUPT2012RC1011
文摘The mobile Intemet industry has exp- erienced dramatic changes as plenty of new applications and business models emerged. This study conducts a qualitative review on the changes through adopting business ecosystem approaches. An analytical framework is estab- lished for reviewing the structure of mobile Internet business ecosystem. Then the core value, key actors, and inter-firm relationships of the mobile Internet ecosystem in the past and in the present are compared. It is found that the ecosystem structure has shifted from an MNO-centric model to a polycentric one with highly expanded value sources and di- versified keystone players. Accordingly some suggestions for regulatory policy makers are provided in terms of the roles of mobile Inter- net in social welfare improvement, the call for a convergent regulatory system, and chal- lenges for information security regulation.
基金supported by the National Natural Science Foundation of China under Grant Nos.61333033and 61690212
文摘A time-variant consensus tracking control problem for networked planar multi-agent systems with non-holonomic constraints is investigated in this paper. In the time-variant consensus tracking problem, a leader agent is expected to track a desired reference input, simultaneously, follower agents are expected to maintain a time-variant formation. To solve the time-variant consensus tracking problem of planar multi-agent systems with non-holonomic constraints, a time-variant consensus tracking control strategy is designed on the basis of an unidirectional topology structure. One of main contributions of this paper is the time-variant consensus tracking protocol for general time-variant formations of planar multi-agent systems with non-holonomic constraints, the other main contribution of this paper is an active predictive control strategy, where predictions of agents are generated actively, so that the computational efficiency is improved than passive approaches. The proposed control strategy is verified by two types of time-varying formations of wheeled mobile robots, and the experimental results show that the proposed control strategy is effective for general time-variant consensus tracking problems of planar multi-agent systems with non-holonomic constraints in local and worldwide networked environments.
