fig3

Figure 3. The framework of low carbon design. ( x is a variable related to mass (M) and energy consumption (CE); every mass M has its corresponding attributes, which are density ρ, material strength σ, the elastic modulus E, and Poisson’s ratio μ, etc.; CE is related to energy consumption factor e; G(x) is the carbon emission and the objective function; g(x) is the constraint function).