k는열 확산 계수, u is temperatureDiffusion equation과 Heat equation은 수학적으로 동일하며, 물리적인 해석만 다르다 Heat equationIn mathematics and physics, the heat equation is a certain partial differential equation. Solutions of the heat equation are sometimes known as caloric functions. The theory of the heat equation was first developed by Joseph Fourier in 1822 for the purpose of modeling how a quantity such as heat diffuses through a given region.https://en.wikipedia.org/wiki/Heat_equation