Seonglae Chok는 확산되는 물질의 양, u is 농도다. 즉 diffusion equation 에서 물질이 heat(energy)인 특정 case가 heat equation
Diffusion equation과 Heat equation은 수학적으로 동일하며, 물리적인 해석만 다르다
Diffusion equation - Wikipedia
The diffusion equation is a parabolic partial differential equation. In physics, it describes the macroscopic behavior of many micro-particles in Brownian motion, resulting from the random movements and collisions of the particles (see Fick's laws of diffusion). In mathematics, it is related to Markov processes, such as random walks, and applied in many other fields, such as materials science, information theory, and biophysics.
https://en.wikipedia.org/wiki/Diffusion_equation