Guangyu HeYingyun SunQiang LuT. LiHairong LvWen Jun YinJ. DongMulti-index and self-approximate-optimal operation for a smart electrical power grid.2201054IBM J. Res. Dev.6https://doi.org/10.1147/JRD.2010.2085461db/journals/ibmrd/ibmrd54.html#HeSLLLYD10