Certain Exponential Time Differencing (ETD) problems are taken into consideration. Since the linear operator exactly preserves the energy norms, we reformulate the ETD problem in the Integrating Factor (IF) form. In turn, the Strong-Stability-Preserving (SSP) schemes could be applied to the reformulated PDE, and a local in time convergence result could be derived via a linearized stability analysis. As a result of this analysis, the third and higher order convergence in time could be theoretically justified, without any condition between the time step and spatial grid sizes. A few examples, including the "Good" oussinesq equation, nonlinear Schrodinger equation, and nonlinear KDV equation, will be covered.

Cheng Wang received his PhD (under Jian-Guo Liu) at Temple University, USA, in 2000. Afterward, he spent 3 years at Indiana University as a postdoc, with Roger Temam and Shouhong Wang as his postdoc mentors. In 2003-2008, he was a tenure-track assistant professor at University of Tennessee. In 2008, he moved to University of Massachusetts dartmouth; right now he is an associate professor there. His research area is applied mathematics, including numerical analysis, partial differential equations, fluid mechanics, computational electro-magnetics, material sciences, etc; he has had over 50 peer-reviewed articles at different scientific journals.