Multiple earth observing satellites need to communicate with each other to observe plenty of targets on the Earth together. The factors, such as external interference, result in satellite information interaction delay...Multiple earth observing satellites need to communicate with each other to observe plenty of targets on the Earth together. The factors, such as external interference, result in satellite information interaction delays, which is unable to ensure the integrity and timeliness of the information on decision making for satellites. And the optimization of the planning result is affected. Therefore, the effect of communication delay is considered during the multi-satel ite coordinating process. For this problem, firstly, a distributed cooperative optimization problem for multiple satellites in the delayed communication environment is formulized. Secondly, based on both the analysis of the temporal sequence of tasks in a single satellite and the dynamically decoupled characteristics of the multi-satellite system, the environment information of multi-satellite distributed cooperative optimization is constructed on the basis of the directed acyclic graph（DAG）. Then, both a cooperative optimization decision making framework and a model are built according to the decentralized partial observable Markov decision process（DEC-POMDP）. After that, a satellite coordinating strategy aimed at different conditions of communication delay is mainly analyzed, and a unified processing strategy on communication delay is designed. An approximate cooperative optimization algorithm based on simulated annealing is proposed. Finally, the effectiveness and robustness of the method presented in this paper are verified via the simulation.展开更多
How to teach reading has become a cornerstone of teachers in China as they develop overall teaching strategies in EFL classrooms.In this paper,firstly the author will introduce the context of teaching reading;thereaft...How to teach reading has become a cornerstone of teachers in China as they develop overall teaching strategies in EFL classrooms.In this paper,firstly the author will introduce the context of teaching reading;thereafter clarify the concept of communicative language teaching(CLT) and its implications in EFL teaching;next illustrate the teaching context in China where CLT is encouraged to be implemented in classrooms;furthermore,reading with a purpose and the relevant teaching techniques will be introduced,in line with the important characteristics of communicative tasks.Finally the author will demonstrate some communicative tasks for purposeful reading in the EFL classroom of a senior high school in China.展开更多
基金supported by the National Science Foundation for Young Scholars of China(6130123471401175)
文摘Multiple earth observing satellites need to communicate with each other to observe plenty of targets on the Earth together. The factors, such as external interference, result in satellite information interaction delays, which is unable to ensure the integrity and timeliness of the information on decision making for satellites. And the optimization of the planning result is affected. Therefore, the effect of communication delay is considered during the multi-satel ite coordinating process. For this problem, firstly, a distributed cooperative optimization problem for multiple satellites in the delayed communication environment is formulized. Secondly, based on both the analysis of the temporal sequence of tasks in a single satellite and the dynamically decoupled characteristics of the multi-satellite system, the environment information of multi-satellite distributed cooperative optimization is constructed on the basis of the directed acyclic graph（DAG）. Then, both a cooperative optimization decision making framework and a model are built according to the decentralized partial observable Markov decision process（DEC-POMDP）. After that, a satellite coordinating strategy aimed at different conditions of communication delay is mainly analyzed, and a unified processing strategy on communication delay is designed. An approximate cooperative optimization algorithm based on simulated annealing is proposed. Finally, the effectiveness and robustness of the method presented in this paper are verified via the simulation.
文摘How to teach reading has become a cornerstone of teachers in China as they develop overall teaching strategies in EFL classrooms.In this paper,firstly the author will introduce the context of teaching reading;thereafter clarify the concept of communicative language teaching(CLT) and its implications in EFL teaching;next illustrate the teaching context in China where CLT is encouraged to be implemented in classrooms;furthermore,reading with a purpose and the relevant teaching techniques will be introduced,in line with the important characteristics of communicative tasks.Finally the author will demonstrate some communicative tasks for purposeful reading in the EFL classroom of a senior high school in China.
