min: K₁ ∑_(1 ≤ i,j ≤ n) x_{i,j} f₁(d_{i,j}) + L₁ ∑_(i=1)^n f₂(t_i) f₁(d) = max(0, (d - K₂))³ f₂(θ) = (θ - L₂)² + L_3?