The interleaving/multiplexing technique was used to realize a 200?MHz real time data acquisition system. Two 100?MHz ADC modules worked parallelly and every ADC plays out data in ping pang fashion. The design improv...The interleaving/multiplexing technique was used to realize a 200?MHz real time data acquisition system. Two 100?MHz ADC modules worked parallelly and every ADC plays out data in ping pang fashion. The design improved the system conversion rata to 200?MHz and reduced the speed of data transporting and storing to 50?MHz. The high speed HDPLD and ECL logic parts were used to control system timing and the memory address. The multi layer print board and the shield were used to decrease interference produced by the high speed circuit. The system timing was designed carefully. The interleaving/multiplexing technique could improve the system conversion rata greatly while reducing the speed of external digital interfaces greatly. The design resolved the difficulties in high speed system effectively. The experiment proved the data acquisition system is stable and accurate.展开更多
In this work, we treat scattering objects, water, surface and bottom in a truly unified manner in a parallel finitedifference time-domain （FDTD） scheme, which is suitable for distributed parallel computing in a mess...In this work, we treat scattering objects, water, surface and bottom in a truly unified manner in a parallel finitedifference time-domain （FDTD） scheme, which is suitable for distributed parallel computing in a message passing interface （MPI） programming environment. The algorithm is implemented on a cluster-based high performance computer system. Parallel computation is performed with different division methods in 2D and 3D situations. Based on analysis of main factors affecting the speedup rate and parallel efficiency, data communication is reduced by selecting a suitable scheme of task division. A desirable scheme is recommended, giving a higher speedup rate and better efficiency. The results indicate that the unified parallel FDTD algorithm provides a solution to the numerical computation of acoustic scattering.展开更多
The interconnection network is one of the key elements of distributed computing systems such as MPP (massively parallel processing) or NOWs (network of workstations).In this paper,a high speed optical interconnection ...The interconnection network is one of the key elements of distributed computing systems such as MPP (massively parallel processing) or NOWs (network of workstations).In this paper,a high speed optical interconnection data link which has been designed and implemented is presented.Using TDM (time division multiplexing),virtual parallel synchronous data transmission between the PCI buses of two computers has been achieved.The maximum data rate of the link is 1 250 Mbit/s,and the communication distance of link is more than 600 m using multi mode fibers.The design method of the high frequency electrical signals on the network interface card has been analyzed,and the efficient data transmission bandwidth of the link in different transmission modes has been tested and analyzed.展开更多
Stereo-electroencephalography （SEEG） is the main investigation method for pre-surgical evaluation of patients suffering from drug-resistant partial epilepsy. SEEG signals reflect two types of paroxysmal activity： i...Stereo-electroencephalography （SEEG） is the main investigation method for pre-surgical evaluation of patients suffering from drug-resistant partial epilepsy. SEEG signals reflect two types of paroxysmal activity： ictal activity and interictal activity or interictal spikes （IS）. The relationship between IS and ictal activity is an essential and recurrent question in epiletology. In this paper, we present a distributed and parallel architecture for space and temporal distribution analysis of IS, based on a distributed and collaborative methodology. The proposed approach exploits the SEEG data using vector analysis of the corresponding signals among multi-agents system. The objective is to present a new method to analyze and classify IS during wakefulness （W）, light sleep （LS） and deep sleep （DS） stages. Temporal and spatial relationships between IS and seizure onset zone are compared during wakefulness, light sleep and deep sleep. Results show that space and temporal distribution for real data are not random but correlated.展开更多
文摘The interleaving/multiplexing technique was used to realize a 200?MHz real time data acquisition system. Two 100?MHz ADC modules worked parallelly and every ADC plays out data in ping pang fashion. The design improved the system conversion rata to 200?MHz and reduced the speed of data transporting and storing to 50?MHz. The high speed HDPLD and ECL logic parts were used to control system timing and the memory address. The multi layer print board and the shield were used to decrease interference produced by the high speed circuit. The system timing was designed carefully. The interleaving/multiplexing technique could improve the system conversion rata greatly while reducing the speed of external digital interfaces greatly. The design resolved the difficulties in high speed system effectively. The experiment proved the data acquisition system is stable and accurate.
基金Project supported by the National Defense Laboratory Foundation (Grant No.51444020103QT0601)the Shanghai Leading Academic Discipline Project (Grant No.T0102)
文摘In this work, we treat scattering objects, water, surface and bottom in a truly unified manner in a parallel finitedifference time-domain （FDTD） scheme, which is suitable for distributed parallel computing in a message passing interface （MPI） programming environment. The algorithm is implemented on a cluster-based high performance computer system. Parallel computation is performed with different division methods in 2D and 3D situations. Based on analysis of main factors affecting the speedup rate and parallel efficiency, data communication is reduced by selecting a suitable scheme of task division. A desirable scheme is recommended, giving a higher speedup rate and better efficiency. The results indicate that the unified parallel FDTD algorithm provides a solution to the numerical computation of acoustic scattering.
文摘The interconnection network is one of the key elements of distributed computing systems such as MPP (massively parallel processing) or NOWs (network of workstations).In this paper,a high speed optical interconnection data link which has been designed and implemented is presented.Using TDM (time division multiplexing),virtual parallel synchronous data transmission between the PCI buses of two computers has been achieved.The maximum data rate of the link is 1 250 Mbit/s,and the communication distance of link is more than 600 m using multi mode fibers.The design method of the high frequency electrical signals on the network interface card has been analyzed,and the efficient data transmission bandwidth of the link in different transmission modes has been tested and analyzed.
文摘Stereo-electroencephalography （SEEG） is the main investigation method for pre-surgical evaluation of patients suffering from drug-resistant partial epilepsy. SEEG signals reflect two types of paroxysmal activity： ictal activity and interictal activity or interictal spikes （IS）. The relationship between IS and ictal activity is an essential and recurrent question in epiletology. In this paper, we present a distributed and parallel architecture for space and temporal distribution analysis of IS, based on a distributed and collaborative methodology. The proposed approach exploits the SEEG data using vector analysis of the corresponding signals among multi-agents system. The objective is to present a new method to analyze and classify IS during wakefulness （W）, light sleep （LS） and deep sleep （DS） stages. Temporal and spatial relationships between IS and seizure onset zone are compared during wakefulness, light sleep and deep sleep. Results show that space and temporal distribution for real data are not random but correlated.
