By using the characteristics of the new building in China, this article constructs the virtual repeat sale method to produce virtual repeat data which is simila
Let H > 0 be a constant, g ≥ 0 be a periodic function and Ω ={(x, y) ||x| H + g (y), y ∈R}. We consider a curvature flow equation V = κ + A in Ω, where for