The design of a turbofan rotor speed control system, using model reference adaptive control（MRAC） method with input and output measurements, is discussed for the purpose of practical application. The nonlinear compe...The design of a turbofan rotor speed control system, using model reference adaptive control（MRAC） method with input and output measurements, is discussed for the purpose of practical application. The nonlinear compensator based on functional link neural network is used to deal with the engine nonlinearity and the hardware-in-loop simulation is also developed. The results show that the nonlinear MRAC controller has the adequate performance of compensating and adapting nonlinearity arising from the change of engine state or working environment. Such feature demonstrates potential practical applications of MRAC for aeroengine control system.展开更多
The dynamic performance and the stability are essential for a system. A new circuit topology used for electrical discharge machining (EDM) power and made up of complex-pulse (voltage-pulse and current-pulse) is presen...The dynamic performance and the stability are essential for a system. A new circuit topology used for electrical discharge machining (EDM) power and made up of complex-pulse (voltage-pulse and current-pulse) is presented. The large-signal model of it is also derived. Based on the comprehensive analysis of the system model, the compensator is designed to make the system match better and to improve its dynamic performance and the stability under perturbations. Finally, the design methods and the analysis are verified by simulation and experimental results.展开更多
Some microscopic traffic simulations on urban road network are developed up to now. However, the effect of urban transport policy in the local city is influenced with the complex interaction of automobile traffic and ...Some microscopic traffic simulations on urban road network are developed up to now. However, the effect of urban transport policy in the local city is influenced with the complex interaction of automobile traffic and public transport traffic. Particularly, behaviours of vehicles should be described with the fuzziness of the subjective recognition and operation. On the other hand, the trip makers are influenced by various transport policies in terms of mode choice behaviour. The change in mode choice behaviour and number of public transport mode users would eventually affect traffic flow conditions on road network. Modal spilt and traffic conditions of a network are interrelated. Therefore, the present study mainly aims to integrate mode choice model and microscopic traffic simulation model based on fuzzy logic. In the study, the fuzzy logic based mode choice model is proposed. The proposed mode choice model and the existing microscopic traffic simulation model are combined. The developed model has been applied on real urban network to demonstrate the effectiveness of the installation of LRT system. Finally, it is helpful for evaluation of transport policy that the fuzzy logic based microscopic traffic simulation with modal choice model has been constructed.展开更多
A self-adapting and reconfigurable routing mechanism is proposed according to the average moving speed of the nodes in mobile ad hoc network （MANET）. This mechanism is based on the perception of moving speed and a p...A self-adapting and reconfigurable routing mechanism is proposed according to the average moving speed of the nodes in mobile ad hoc network （MANET）. This mechanism is based on the perception of moving speed and a predesigned selection metric to choose the optimal routing protocol. The routing evaluation and selection metric is derived by OPNET simulations. AODV and OLSR are used as the example to show the process of this mechanism with the moving speed varying. The routing protocol can be configured without central configuration and human management. Besides, the overhead of the mechanism is reasonable and doesnot affect the quality of service （QoS） of the traffic in the network. Results show that the optimal routing protocol can be configured adaptively according to the speed so that better performance than end-to-end delay and packet delivery ratio. a specific protocol can be obtained in terms of展开更多
Based on the discrete time method, an effective movement control model is designed for a group of high- speed trains on a rail network. The purpose of the model is to investigate the specific traffic characteristics o...Based on the discrete time method, an effective movement control model is designed for a group of high- speed trains on a rail network. The purpose of the model is to investigate the specific traffic characteristics of high-speed trains under the interruption of stochastic irregular events. In the model, the high-speed rail traffic system is supposed to be equipped with the moving-block signalling system to guarantee maximum traversing capacity of the railway. To keep the safety of trains＇ movements, some operational strategies are proposed to control the movements of trains in the model, including traction operation, braking operation, and entering-station operation. The numerical simulations show that the designed model can well describe the movements of high-speed trains on the rail network. The research results can provide the useful information not only for investigating the propagation features of relevant delays under the irregular disturbance but also for rerouting and reseheduling trains on the rail network.展开更多
Along with the completion of HGP （human genome project）, huge amounts of genetic data constantly emerge. Research suggests that genes are not in independent existence and the expression of a gene will promote or inh...Along with the completion of HGP （human genome project）, huge amounts of genetic data constantly emerge. Research suggests that genes are not in independent existence and the expression of a gene will promote or inhibit the expression of another gene; if the expression of a gene makes the biochemical environment of ceils changed, the expression of a series of genes will be affected. In order to get a better understanding of the relationship between genes, all sorts of gene regulatory network models have been established by scientists. In this paper, a variety of gene regulatory networks are first introduced according to the process of this subject research, and then the most basic network （i.e. Boolean network） is emphatically analyzed, and then a new method （i.e. Boolean network based on the theory of circuit） to describe Boolean network is drawn forth. After the shortcomings of the Boolean network proposed in the past are analyzed, a simulation circuit Boolean model is established using EDA technology in order to improve the Boolean network.展开更多
文摘The design of a turbofan rotor speed control system, using model reference adaptive control（MRAC） method with input and output measurements, is discussed for the purpose of practical application. The nonlinear compensator based on functional link neural network is used to deal with the engine nonlinearity and the hardware-in-loop simulation is also developed. The results show that the nonlinear MRAC controller has the adequate performance of compensating and adapting nonlinearity arising from the change of engine state or working environment. Such feature demonstrates potential practical applications of MRAC for aeroengine control system.
文摘The dynamic performance and the stability are essential for a system. A new circuit topology used for electrical discharge machining (EDM) power and made up of complex-pulse (voltage-pulse and current-pulse) is presented. The large-signal model of it is also derived. Based on the comprehensive analysis of the system model, the compensator is designed to make the system match better and to improve its dynamic performance and the stability under perturbations. Finally, the design methods and the analysis are verified by simulation and experimental results.
文摘Some microscopic traffic simulations on urban road network are developed up to now. However, the effect of urban transport policy in the local city is influenced with the complex interaction of automobile traffic and public transport traffic. Particularly, behaviours of vehicles should be described with the fuzziness of the subjective recognition and operation. On the other hand, the trip makers are influenced by various transport policies in terms of mode choice behaviour. The change in mode choice behaviour and number of public transport mode users would eventually affect traffic flow conditions on road network. Modal spilt and traffic conditions of a network are interrelated. Therefore, the present study mainly aims to integrate mode choice model and microscopic traffic simulation model based on fuzzy logic. In the study, the fuzzy logic based mode choice model is proposed. The proposed mode choice model and the existing microscopic traffic simulation model are combined. The developed model has been applied on real urban network to demonstrate the effectiveness of the installation of LRT system. Finally, it is helpful for evaluation of transport policy that the fuzzy logic based microscopic traffic simulation with modal choice model has been constructed.
文摘A self-adapting and reconfigurable routing mechanism is proposed according to the average moving speed of the nodes in mobile ad hoc network （MANET）. This mechanism is based on the perception of moving speed and a predesigned selection metric to choose the optimal routing protocol. The routing evaluation and selection metric is derived by OPNET simulations. AODV and OLSR are used as the example to show the process of this mechanism with the moving speed varying. The routing protocol can be configured without central configuration and human management. Besides, the overhead of the mechanism is reasonable and doesnot affect the quality of service （QoS） of the traffic in the network. Results show that the optimal routing protocol can be configured adaptively according to the speed so that better performance than end-to-end delay and packet delivery ratio. a specific protocol can be obtained in terms of
基金Supported by the National Natural Science Foundation of China under Grant No. 70901006Research Foundation of Beijing Jiaotong University under Grant Nos. 2011JBM158, 2011JBM162Research Foundation of State Key Laboratory of Rail Traffic Control and Safety under Grant Nos. RCS2009ZT001, RCS2010ZZ001
文摘Based on the discrete time method, an effective movement control model is designed for a group of high- speed trains on a rail network. The purpose of the model is to investigate the specific traffic characteristics of high-speed trains under the interruption of stochastic irregular events. In the model, the high-speed rail traffic system is supposed to be equipped with the moving-block signalling system to guarantee maximum traversing capacity of the railway. To keep the safety of trains＇ movements, some operational strategies are proposed to control the movements of trains in the model, including traction operation, braking operation, and entering-station operation. The numerical simulations show that the designed model can well describe the movements of high-speed trains on the rail network. The research results can provide the useful information not only for investigating the propagation features of relevant delays under the irregular disturbance but also for rerouting and reseheduling trains on the rail network.
文摘Along with the completion of HGP （human genome project）, huge amounts of genetic data constantly emerge. Research suggests that genes are not in independent existence and the expression of a gene will promote or inhibit the expression of another gene; if the expression of a gene makes the biochemical environment of ceils changed, the expression of a series of genes will be affected. In order to get a better understanding of the relationship between genes, all sorts of gene regulatory network models have been established by scientists. In this paper, a variety of gene regulatory networks are first introduced according to the process of this subject research, and then the most basic network （i.e. Boolean network） is emphatically analyzed, and then a new method （i.e. Boolean network based on the theory of circuit） to describe Boolean network is drawn forth. After the shortcomings of the Boolean network proposed in the past are analyzed, a simulation circuit Boolean model is established using EDA technology in order to improve the Boolean network.
