Let $v_{1}, v_{2}, v_{3} \in \mathbb{R}^{3}$ be given by $v_{1}=(1,2,1), v_{2}=(1,-2,1)$, and $v_{3}=(1,2,-1)$. Apply the Gram-Schmidt procedure to the basis $\left(v_{1}, v_{2}, v_{3}\right)$ of $\mathbb{R}^{3}$, and call the resulting orthonormal basis $\left(u_{1}, u_{2}, u_{3}\right)$.