A new technique to filter reduction for speech signal processing systems. - Luowen Li; Lihua Xie 001; Gang Li; Yeng Chai Soh (ICASSP, 1999)

Frequency weighted optimal order reduction of digital filters. - Luowen Li; Lihua Xie 001; Wei-Yong Yan; Yeng Chai Soh (Signal Process., 1999)

Design of low-order linear-phase IIR filters via orthogonal projection. - Luowen Li; Lihua Xie 001; Wei-Yong Yan; Yeng Chai Soh (IEEE Trans. Signal Process., 1999)

A Gradient Flow Approach to Optimal Model Reduction of Discrete-Time Periodic Systems. - Lihua Xie 001; Cishen Zhang; Luowen Li (J. Glob. Optim., 2002)