136 research outputs found

    A Large-Scale Particle Image Velocimetry System Based on Dual-camera Field of View Stitching

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    Large-Scale Particle Image Velocimetry (LSPIV) is an effective method for the measurement of the river surface flow velocity. For the wide cross-section river, in the near-field area of river surface image there are small and clear targets. But the flow tracers are almost invisible in the far-field area because of the resolution limit of one single video camera, which makes it difficult to complete the velocimetry task. So a dual-camera based LSPIV system has been developed for monitoring the wide cross-section river. This system is based on two digital Internet Protocol (IP) video cameras either of which captures more than half of the river surface with high resolution. And then the developed system stitches the two images into one covering the entire wide cross-section rivers. In the far field of river, the accuracy of the vector increases from 20.4 % to 80.4 %

    Neuromorphic computing using wavelength-division multiplexing

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    Optical neural networks (ONNs), or optical neuromorphic hardware accelerators, have the potential to dramatically enhance the computing power and energy efficiency of mainstream electronic processors, due to their ultralarge bandwidths of up to 10s of terahertz together with their analog architecture that avoids the need for reading and writing data back and forth. Different multiplexing techniques have been employed to demonstrate ONNs, amongst which wavelength division multiplexing (WDM) techniques make sufficient use of the unique advantages of optics in terms of broad bandwidths. Here, we review recent advances in WDM based ONNs, focusing on methods that use integrated microcombs to implement ONNs. We present results for human image processing using an optical convolution accelerator operating at 11 Tera operations per second. The open challenges and limitations of ONNs that need to be addressed for future applications are also discussed.Comment: 13 pages, 8 figures, 160 reference
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