5 citations · 8 across the 4 of their papers we have counts for
6 papers
When Small Gain Meets Small Phase
Di Zhao, Wei Chen, Li Qiu
In this paper, we investigate the feedback stability of multiple-input multiple-output linear time-invariant systems with combined gain and phase information. To begin with, we exp…
A Frequency-Domain Approach to Nonlinear Negative Imaginary Systems Analysis
Di Zhao, Chao Chen, Sei Zhen Khong
In this study, we extend the theory of negative imaginary (NI) systems to a nonlinear framework using a frequency-domain approach. The extended notion is completely characterized v…
Phase of Nonlinear Systems
Chao Chen, Di Zhao, Wei Chen +2
In this paper, we propose a definition of phase for a class of stable nonlinear systems called semi-sectorial systems, from an input-output perspective. The definition involves the…
Low Phase-Rank Approximation
Di Zhao, Axel Ringh, Li Qiu +1
In this paper, we propose and solve a low phase-rank approximation problem, which serves as a counterpart to the well-known low-rank approximation problem and the Schmidt-Mirsky th…
Stabilization of Cascaded Two-Port Networked Systems with Simultaneous Nonlinear Uncertainties
Di Zhao, Sei Zhen Khong, Li Qiu
We introduce a versatile framework to model and study networked control systems (NCSs). An NCS is described as a feedback interconnection of a plant and a controller communicating…
A Convex Approach to Frisch-Kalman Problem
Di Zhao, Anders Rantzer, Li Qiu
This paper proposes a convex approach to the Frisch-Kalman problem that identifies the linear relations among variables from noisy observations. The problem was proposed by Ragnar…