Sufficient and Necessary Condition of Admissibility for Fractional-order   Singular System
  This paper has been withdrawn. This paper focuses on the admissibility condition for fractional-order singular system with order $\alpha \in (0,1)$. The definitions of regularity, impulse-free and admissibility are given first, then a sufficient and necessary condition of admissibility for fractional-order singular system is established. A numerical example is included to illustrate the proposed condition. 
Zhuang Jiao and Yisheng Zhong
cs.SY math.OC