Zhiyun Li

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A theory and a system for capturing an audio scene and then rendering it remotely are developed and presented. The sound capture is performed with a spherical microphone array. The sound field at the location of the array is deduced from the captured sound and is represented using either spherical wave-functions or plane-wave expansions. The sound field(More)
—This paper describes a methodology for designing a flexible and optimal spherical microphone array for beamforming. Using the approach presented, a spherical microphone array can have very flexible layouts of microphones on the spherical surface , yet optimally approximate a desired beampattern of higher order within a specified robustness constraint.(More)
This paper describes an approach to achieving a flexible layout of microphones on the surface of a spherical microphone array for beamforming. Our approach achieves orthonor-mality of spherical harmonics to higher order for relatively distributed layouts. This gives great flexibility in microphone layout on the spherical surface. One direct advantage is it(More)
Virtual reality systems are largely based on computer graphics and vision technologies. However, sound also plays an important role in human's interaction with the surrounding environment, especially for the visually impaired people. In this paper, we will develop the theory of recording and reproducing real-world surround auditory scenes in high orders(More)
Spherical microphone arrays have attracted attention for analyzing the sound field in a region and beamforming. The analysis of the recorded sound has been performed in terms of spherical wave-functions, and recently the use of plane-wave expansions has been suggested. We show that the plane-wave basis is intimately related to the spherical wave-functions.(More)
Hypoxic and low-glucose stressors contribute to neuronal death in many brain diseases. Astrocytes are anatomically well-positioned to shield neurons from hypoxic injury. During hypoxia/ischemia, lactate released from astrocytes is taken up by neurons and stored for energy. This process is mediated by monocarboxylate transporters (MCTs) in the central(More)
We propose a unified and simple approach of capturing and recreating 3D sound fields by exploring the reciprocity principle that is satisfied between the two processes. Our approach makes the system easy to build, and practical. Using this approach, we can capture the 3D sound field by a spherical microphone array and recreate it using a spherical(More)
We describe a robust and self-reconfigurable design of a spherical microphone array for beamforming. Our approach achieves a multi-resolution spherical beamformer with performance that is either optimal in the approximation of desired beampattern or is optimal in the directivity achieved, both robustly. Our implementation converges to the optimal(More)