Operational state complexity of nested word automata. - Xiaoxue Piao; Kai Salomaa (Theor. Comput. Sci., 2009)

Operational State Complexity of Deterministic Unranked Tree Automata - Xiaoxue Piao; Kai Salomaa (DCFS, 2010)

Transformations Between Different Types of Unranked Bottom-Up Tree Automata - Xiaoxue Piao; Kai Salomaa (DCFS, 2010)

Tree Homomorphisms for Unranked Trees. - Xiaoxue Piao; Kai Salomaa; Sándor Vágvölgyi (AFL, 2011)

State Trade-Offs in Unranked Tree Automata. - Xiaoxue Piao; Kai Salomaa (DCFS, 2011)

Transformations Between Different Models of Unranked Bottom-Up Tree Automata. - Xiaoxue Piao; Kai Salomaa (Fundam. Informaticae, 2011)

Descriptional Complexity of Input-Driven Pushdown Automata. - Alexander Okhotin; Xiaoxue Piao; Kai Salomaa (Languages Alive, 2012)

State Complexity of Kleene-Star Operations on Trees. - Xiaoxue Piao; Kai Salomaa (Computation, Physics and Beyond, 2012)

State Complexity of Projection and Quotient on Unranked Trees. - Xiaoxue Piao; Kai Salomaa (DCFS, 2012)

State complexity of the concatenation of regular tree languages. - Xiaoxue Piao; Kai Salomaa (Theor. Comput. Sci., 2012)

Lower bounds for the size of deterministic unranked tree automata. - Xiaoxue Piao; Kai Salomaa (Theor. Comput. Sci., 2012)

State Complexity of Tree Automata. - Xiaoxue Piao (2012)

A prediction-based adaptive grouping differential evolution algorithm for constrained numerical optimization. - Xiangyong Kong; Haibin Ouyang; Xiaoxue Piao (Soft Comput., 2013)

State Complexity of Kleene-Star Operations on Regular Tree Languages. - Yo-Sub Han; Sang-Ki Ko; Xiaoxue Piao; Kai Salomaa (Acta Cybern., 2015)