Liejun Xie

Work place: Department of Mathematics, Ningbo University, Zhejiang Ningbo 315211, China



Research Interests: Computational Mathematics, Mathematics


Liejun Xie was born in Zhejiang Province of China on April 24, 1974. He received the M.S. degree in Fundamental Mathematics. His main research interests include the mechanization for mathematics, Rough set and its application and mathematical education research. Currently, he works in the Mathematics Department of Ningbo University. He is an associate professor. He has published 17 research papers in journals and international conferences in mathematical and computer field. Some papers of them have been indexed by MR, EI and ISTP: Two theorems for determining p-irreducibility of binding polynomials with degree four(China, Pure Appl. Math. 24, No. 2, 314-320,2008); Some results for determining p-irreducibility of binding polynomials (China, J. Zhejiang Univ. Sci. Ed. 35, No.3, 241- 247, 2008); A note on the Sturm theorem(China, Math. Practice Theory, 37, No.1 121-125, 2007); A new algorithm for determining sign of real algebraic numbers (China, Bull. Of Sci. and Tech. 23, No.3, 303-307, 2007). He has presided or participated 12 research projects including National Research Projects, Provincial and City Research Projects. Mr. XIE is the associate deputy of the Department of Mathematics at Ningbo University, the deputy of Mathematical laboratory. He covered himself with honorary of excellent theses in science field of Zhejiang province in 2005.


Author Articles
A Criterion for Hurwitz Polynomials and its Applications

By Liejun Xie

DOI:, Pub. Date: 8 Feb. 2011

We present a new criterion to determine the stability of polynomial with real coefficients. Combing with the existing results of the real and negative roots discrimination, we deduced the explicit conditions of stability for any real polynomial with a degree no more than four. Meanwhile, we discussed the problem of controls system stability and inertia of Bezout matrix as the applications of the criterion. A necessary and sufficient condition to determine the stability of the characteristic polynomial of the continuous time control systems was proposed. And also, we discussed a pathological case of the bilinear transformation, which can convert the stability analysis of a given discrete time system to the corresponding continuous time system, and brought forward an alternative one.

[...] Read more.
Other Articles