As a new fishery mode of low-carbon economy, marine ranching has played an important role in promoting sustainable development of fishery and construction of ocean economic zone in China. Since the year of 2000, envir...As a new fishery mode of low-carbon economy, marine ranching has played an important role in promoting sustainable development of fishery and construction of ocean economic zone in China. Since the year of 2000, environment improvement, stock enhancement and mariculture development have been given very high degree of importance along the coast of Shandong Province of China. Studies and tests on artificial reefs and marine ranching, including effect investigation of artificial reefs set up in Jiaonan coastal areas in 1980s, hydrodynamic characteristics experiment of artificial reef, study on material and configuration of artificial reef models, algae transplantation and seaweed beds construction, stock enhancement and releasing etc., have been carried out in recent years. Furthermore, the Restoration Plan of Fishery Resources of Shandong Province has been implemented since the year of 2005, which greatly boosted the construction of artificial reefs and marine ranching along the coast of Shandong. By June of 2010, the total investment on the construction of artificial reefs and marine ranching is over $77 million USD. One hundred artificial reef districts, with total area about 33,350,000 m2 have been set up. The construction of marine ranching along the coast of Shandong Province has been in certain scale and the economic, social and ecological effects are obvious.展开更多
The interception problem of Hypersonic Gliding Vehicles(HGVs)has been an important aspect of missile defense systems.In order to provide interceptors with accurate information of target trajectory,a model based on an ...The interception problem of Hypersonic Gliding Vehicles(HGVs)has been an important aspect of missile defense systems.In order to provide interceptors with accurate information of target trajectory,a model based on an improved Long Short-Time Memory(LSTM)network for trajectory prediction pipeline is proposed for the interception of a skip gliding hypersonic target.Firstly,for trajectory prediction required by intercepting guidance laws,the altitude,velocity and velocity direction of the target are formulated in the form of analytic functions,consisting of linear decay terms and amplitude decay sinusoidal terms.Then,the dynamic characteristics of the model parameters are analyzed,and the target trajectory prediction pipeline is proposed with the prediction error considered.Finally,an improved LSTM network is designed to estimate parameters in a dynamically-updated manner,and estimation results are used for the calculation of the final trajectory prediction pipeline.The proposed prediction algorithm provides information on the velocity vector for midcourse guidance with the effect of prediction errors on interception taken into account.Simulation is conducted and the results show the high accuracy of the algorithm in HGVs’trajectory prediction which is conducive to increasing the interception success rate.展开更多
This paper presents finite-time control methods with H-infinity constraints for linear time-invariant (LTI) and time-varying (LTV) systems. The basic idea of the proposed approaches is to construct controllers for...This paper presents finite-time control methods with H-infinity constraints for linear time-invariant (LTI) and time-varying (LTV) systems. The basic idea of the proposed approaches is to construct controllers for the LTI and LTV in such a way that a constant quadratic Lyapunov function and a time-varying quadratic Lyapunov function can be used to establish the finite-time stability and the H-infinity performance of the resulting closed-loop systems. It is shown that the control laws can be obtained by solving a set of linear matrix inequalities (LMIs) and Differential Riccati Inequalities (DRIs) that are numerically feasible with commercially available software. Finally, the results are illustrated by application to the design of guidance law for a class of terminal guidance system.展开更多
文摘As a new fishery mode of low-carbon economy, marine ranching has played an important role in promoting sustainable development of fishery and construction of ocean economic zone in China. Since the year of 2000, environment improvement, stock enhancement and mariculture development have been given very high degree of importance along the coast of Shandong Province of China. Studies and tests on artificial reefs and marine ranching, including effect investigation of artificial reefs set up in Jiaonan coastal areas in 1980s, hydrodynamic characteristics experiment of artificial reef, study on material and configuration of artificial reef models, algae transplantation and seaweed beds construction, stock enhancement and releasing etc., have been carried out in recent years. Furthermore, the Restoration Plan of Fishery Resources of Shandong Province has been implemented since the year of 2005, which greatly boosted the construction of artificial reefs and marine ranching along the coast of Shandong. By June of 2010, the total investment on the construction of artificial reefs and marine ranching is over $77 million USD. One hundred artificial reef districts, with total area about 33,350,000 m2 have been set up. The construction of marine ranching along the coast of Shandong Province has been in certain scale and the economic, social and ecological effects are obvious.
基金co-supported by the National Natural Science Foundation of China(No.61427809).
文摘The interception problem of Hypersonic Gliding Vehicles(HGVs)has been an important aspect of missile defense systems.In order to provide interceptors with accurate information of target trajectory,a model based on an improved Long Short-Time Memory(LSTM)network for trajectory prediction pipeline is proposed for the interception of a skip gliding hypersonic target.Firstly,for trajectory prediction required by intercepting guidance laws,the altitude,velocity and velocity direction of the target are formulated in the form of analytic functions,consisting of linear decay terms and amplitude decay sinusoidal terms.Then,the dynamic characteristics of the model parameters are analyzed,and the target trajectory prediction pipeline is proposed with the prediction error considered.Finally,an improved LSTM network is designed to estimate parameters in a dynamically-updated manner,and estimation results are used for the calculation of the final trajectory prediction pipeline.The proposed prediction algorithm provides information on the velocity vector for midcourse guidance with the effect of prediction errors on interception taken into account.Simulation is conducted and the results show the high accuracy of the algorithm in HGVs’trajectory prediction which is conducive to increasing the interception success rate.
基金supported by the National Natural Science Foundation of China(Nos.61004128,61074160,61104193)
文摘This paper presents finite-time control methods with H-infinity constraints for linear time-invariant (LTI) and time-varying (LTV) systems. The basic idea of the proposed approaches is to construct controllers for the LTI and LTV in such a way that a constant quadratic Lyapunov function and a time-varying quadratic Lyapunov function can be used to establish the finite-time stability and the H-infinity performance of the resulting closed-loop systems. It is shown that the control laws can be obtained by solving a set of linear matrix inequalities (LMIs) and Differential Riccati Inequalities (DRIs) that are numerically feasible with commercially available software. Finally, the results are illustrated by application to the design of guidance law for a class of terminal guidance system.