[IEEE 2019 IEEE Nordic Circuits and Systems Conference (NORCAS): NORCHIP and International Symposium of System-on-Chip (SoC) - Helsinki, Finland (2019.10.29-2019.10.30)] 2019 IEEE Nordic Circuits and Systems Conference (NORCAS): NORCHIP and International Symposium of System-on-Chip (SoC) - Ultra-Low Voltage Subthreshold Binary Adder Architectures for IoT Applications: Ripple Carry Adder or Kogge Stone Adder