“…where c i and d i are the coefficients of reproducing kernel and can be determined by solving a uniquely solvable linear system of algebraic equations, which is completely explained in Cui and Lin (2009). For more details about the method of obtaining kernel K (x, y), refer to Cui and Lin (2009), Geng and Cui (2007), and Li and Cui (2003). a, b] and, therefore, it is also a reproducing kernel space.…”