The use of underwater acoustic data has rapidly expanded with the application of multichannel, large-aperture underwater detection arrays. This study presents an underwater acoustic data compression method that is bas...The use of underwater acoustic data has rapidly expanded with the application of multichannel, large-aperture underwater detection arrays. This study presents an underwater acoustic data compression method that is based on compressed sensing. Underwater acoustic signals are transformed into the sparse domain for data storage at a receiving terminal, and the improved orthogonal matching pursuit(IOMP) algorithm is used to reconstruct the original underwater acoustic signals at a data processing terminal. When an increase in sidelobe level occasionally causes a direction of arrival estimation error, the proposed compression method can achieve a 10 times stronger compression for narrowband signals and a 5 times stronger compression for wideband signals than the orthogonal matching pursuit(OMP) algorithm. The IOMP algorithm also reduces the computing time by about 20% more than the original OMP algorithm. The simulation and experimental results are discussed.展开更多
Hidden terminal problem in spectrum sensing is one of the most challenging problems in cognitive radio network(CRN).To tackle this problem,we propose a novel Cooperative Interference Game scheme in this paper.The sche...Hidden terminal problem in spectrum sensing is one of the most challenging problems in cognitive radio network(CRN).To tackle this problem,we propose a novel Cooperative Interference Game scheme in this paper.The scheme adopted full duplex(FD)mode to sense over multiple sub-bands in an iterative manner without extra sensing devices.The implementation algorithm of the proposed scheme is consisted of three modules:the formulation of the maximum transmit power limitation of second user(SU);the self-interference cancellation coefficient;and the optimal location of SU for an optimized low collision probability.Monte Carlo simulation proved that compared with cooperative spectrum sensing,the proposed scheme significantly improves the performance of spectrum detection and mitigates hidden terminal problem to a large extent with less energy consumption.展开更多
As administration ofblogs is one of the most popular activities on the Internet currently, topics related to blogs have also become a favorite subject in daily life. Questions like what ways can be used to show end-us...As administration ofblogs is one of the most popular activities on the Internet currently, topics related to blogs have also become a favorite subject in daily life. Questions like what ways can be used to show end-users＇ or designers＇ internal knowledge to find out their needs, what methods can be applied to analysis of the process, etc., have not been answered yet. Therefore, how to analyze the tacit knowledge and grasp the true demand of users is one of the major issues to be solved in empathic design. The purpose of this research is to examine the difference of whether the ＂comparison table of schema changes for users at three points of time＂ was taken into consideration or not in an empathic design brainstorming meeting. The tests consist of the experimental group and the control group. The former did not refer to the comparison table; however, the latter used it for discussion. The result indicates this comparison table helped the control group significantly in presenting an ultimate blog design of innovative ideas展开更多
基金Project(11174235)supported by the National Natural Science Foundation of ChinaProject(3102014JC02010301)supported by the Fundamental Research Funds for the Central Universities,China
文摘The use of underwater acoustic data has rapidly expanded with the application of multichannel, large-aperture underwater detection arrays. This study presents an underwater acoustic data compression method that is based on compressed sensing. Underwater acoustic signals are transformed into the sparse domain for data storage at a receiving terminal, and the improved orthogonal matching pursuit(IOMP) algorithm is used to reconstruct the original underwater acoustic signals at a data processing terminal. When an increase in sidelobe level occasionally causes a direction of arrival estimation error, the proposed compression method can achieve a 10 times stronger compression for narrowband signals and a 5 times stronger compression for wideband signals than the orthogonal matching pursuit(OMP) algorithm. The IOMP algorithm also reduces the computing time by about 20% more than the original OMP algorithm. The simulation and experimental results are discussed.
基金supported by National High-Tech R&D Program(863 Program 2014AA01A707, 2015AA01A705 )
文摘Hidden terminal problem in spectrum sensing is one of the most challenging problems in cognitive radio network(CRN).To tackle this problem,we propose a novel Cooperative Interference Game scheme in this paper.The scheme adopted full duplex(FD)mode to sense over multiple sub-bands in an iterative manner without extra sensing devices.The implementation algorithm of the proposed scheme is consisted of three modules:the formulation of the maximum transmit power limitation of second user(SU);the self-interference cancellation coefficient;and the optimal location of SU for an optimized low collision probability.Monte Carlo simulation proved that compared with cooperative spectrum sensing,the proposed scheme significantly improves the performance of spectrum detection and mitigates hidden terminal problem to a large extent with less energy consumption.
文摘As administration ofblogs is one of the most popular activities on the Internet currently, topics related to blogs have also become a favorite subject in daily life. Questions like what ways can be used to show end-users＇ or designers＇ internal knowledge to find out their needs, what methods can be applied to analysis of the process, etc., have not been answered yet. Therefore, how to analyze the tacit knowledge and grasp the true demand of users is one of the major issues to be solved in empathic design. The purpose of this research is to examine the difference of whether the ＂comparison table of schema changes for users at three points of time＂ was taken into consideration or not in an empathic design brainstorming meeting. The tests consist of the experimental group and the control group. The former did not refer to the comparison table; however, the latter used it for discussion. The result indicates this comparison table helped the control group significantly in presenting an ultimate blog design of innovative ideas
