Li, Zhaohui
Associate Professor
Research Interests: Underwater acoustics, transduction, signal processing
Office Phone: 86-10-6276 3933
Email: lizh@ele.pku.edu.cn
Li, Zhaohui is an associate professor in the School of EECS, Peking University. He obtained his B.S. and M.S. degrees in acoustics, as well as Ph.D. in signal processing from Peking University in 1987, 1992 and 2005 respectively. His research interests include underwater acoustics, transduction, and signal processing.
Dr. LI has published more than 20 research papers, and most of them are published in top journals in the field, such as IEEE J. Oceanic Eng., IEEE Trans. UFFC, Sensors and Actuators, J. Sound. Vib., et al. He has several innovations been granted by the Patent Office of China. He has been the director of The Center of Underwater Acoustics and Sensing Technologies, Institute of Advanced Technology, Peking University since 2011. He is now a council member of The Acoustical Society of China, and a committee member of The National Acoustical Standardization Technical Committee, as well as the vice chairman of Beijing Acoustical Society.
His research achievements are summarized as follows:
1) Underwater acoustical imaging: Wideband or ultra-wideband acoustical imaging can provide high/ultra-high resolution compared to widely used narrowband imaging, which however means tremendous hardware cost in array channels and excessive computational burden in beamforming. He proposed a fast algorithm based on non-uniform FFT to calculate wideband beam patterns of arbitrary 2-D arrays, which makes it possible to implement high resolution 3-D imaging through designing ultra-sparse 2-D arrays and real-time beamforming. All the relative papers published in IEEE J. Oceanic Eng. and IEEE Trans. UFFC attracted keen interests of readers in the field and entered the list of the top 50 popular articles of the two journals in many months, of which one ever reached the 2nd of the most popular articles.
2) Acoustical Doppler Current Profiling: He established the criterion of waveform design for ADCP theoretically, and proposed a multi-phase coding method to realize the design, which can provide higher measurement accuracy of the ADCPs than common binary coding methods. The relative paper published in IEEE J. Oceanic Eng. also attracted keen interests of readers in the field and entered the list of the top 50 popular articles of the journal in many months.
3) Semi-active sound absorption: He proposed an indirect method to test the elastic constant changing with the shunt circuits of the piezoelectric materials, with which he investigated the choosing of piezoelectric damping materials and proposed a 2-1-3 piezoelectric composite type to implement the semi-active sound absorption. He setup the layering transmission theory to analyze the sound absorption performance of multi-layer piezoelectric coatings. And first in the field, he manufactured the piezoelectric coating protypes to verify the theory by experiments. Serials of his published work established a foundation to the researches of semi-active sound absorption of underwater anechoic coatings.
