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991.
992.
993.
Skewed Data Partition and Alignment Techniques for Compiling Programs on Distributed Memory Multicomputers 总被引:3,自引:0,他引:3
Minimizing data communication over processors is the key to compile programs for distributed memory multicomputers. In this paper, we propose new data partition and alignment techniques for partitioning and aligning data arrays with a program in a way of minimizing communication over processors. We use skewed alignment instead of the dimension-ordered alignment techniques to align data arrays. By developing the skewed scheme, we can solve more complex programs with minimized data communication than that of the dimension-ordered scheme. Finally, we compare the proposed scheme with the dimension-ordered alignment one by experimental results. The experimental results show that our proposed scheme has more opportunities to align data arrays such that data communications over processors can be minimized. 相似文献
994.
Henk Martijn Urban Halldin Per Helander Jan Y. Andersson 《Analog Integrated Circuits and Signal Processing》2000,22(1):71-79
A readout circuit for a 640 × 480 pixels FPA (focal plane array) has been successfully designed, fabricated and tested. The circuit solution is based on a per pixel source-follower direct injection (SFDI) pre-amplifier. Signal multiplexing is performed in both X and Y direction. The pixel size is 25 m × 25m. The chip is optimized for a QWIP (quantum well infrared photodetector) operating at a temperature of 70 K. The circuit has been realized in a standard 0.8 m CMOS process. 相似文献
995.
讨论了一种常规低分辨力雷达对运动目标进行横向一维高分辨力成象的方法,并通过计算机仿真证实了方法的可行性。这有助于实现常规雷达对目标的识别和分类。 相似文献
996.
In array signal processing,the existing methods for DOA estimation of wide-band signals are only related to the azimuth estimation when the number or sensors is known.It is shown that a circular array possesses several nice properties.2-D spatial-spectrum estimation for wide-band sources is performed by using a circular array of sensors with sample delay lines.Further,the Choi' s approach is extended,which was suggested to estimate DOA of narrow-band signals when the number of sensor was unknown,to wide-band signal processing.The extended approach is shown to be quite adequate for wide-band signal subspace spatial-spectrum estimation (BASS-LE),and a large aperture (r>λvin/2) circular array is found to possess superior resolution capability and robustness. 相似文献
997.
平衡二阶相关免疫函数的构造 总被引:1,自引:0,他引:1
温巧燕 《西安邮电学院学报》1996,1(4):28-29,48
构造了一大类平衡的二阶相关免疫函数,从而给出了二阶相关免疫函数个数的一个更好的下界公式 相似文献
998.
The relatively low piezoelectric constant of the aluminum nitride piezoelectric film limits the development and application of the piezoelectric micro-machined ultrasonic transducer based on the aluminum nitride. Therefore, the directivity of the piezoelectric micro-machined ultrasonic transducer array is studied for this problem. First, the far-field sound pressure and normalized directivity function of the transducer array are calculated according to the Rayleigh principle. Furthermore, the effects of array element radius, array element spacing, array element number and operating frequency on the beam width, direction sharpness angle and sidelobe level of the array are analyzed, and the transducer array is optimized. Finally, based on the optimization results, area and filling efficiency, the final structure size of the transducer array is determined and the sound pressure distribution visually simulated. The results show that the optimized transducer array has an ideal sound pressure distribution, good directivity and sharp main lobe. The-3dB beamwidth of the main lobe is about 9 ° and the sidelobe level is about 0.228. 相似文献
999.
In order to handle the low accuracy of the algorithm DCS-SOMP, two underdetermined wideband direction of arrival estimation methods with a high accuracy are proposed from the perspective of multiple iteration. First, the wideband signal processing model using the sparse array is established and transformed into a distributed compressive sensing problem through sparse representation. Then, the noises are eliminated through matrix transformation. After that, an algorithm utilizing proximity searching is proposed to improve the estimation accuracy and an algorithm based on the refined grid is proposed to compensate grid mismatch. Simulation results show that the proposed algorithms outperform the DCS-SOMP with a higher estimation accuracy and possess the advantage in computational speed. 相似文献
1000.
In order to improve the network recognition accuracy in the low complexity condition, a piecewise linear sigmoid function approximation based on the distribution probability of the neurons’ values is proposed only with one addition circuit. The sigmoid function is first divided into three fixed regions. Second, according to the neurons’ values distribution probability, the curve in each region is segmented into sub-regions to reduce the approximation error and improve the recognition accuracy. The slope of the piecewise linear function is set as 2-n, effectively reducing the hardware implementation complexity. Experiments performed on Xilinx’s FPGA-XC7A200T implement the MNIST handwritten digits recognition. The results show that the proposed method achieves a 97.45% recognition accuracy in a deep neural network and 98.42% in a convolutional neural network, up to 0.84% and 0.57% higher than other approximation methods only with one addition circuit. 相似文献