Finally having completed the required textbook reading and exercises, Alejandro moved on the next stage of his internship. He was introduced to a circuit modeling and simulation program called Cadence Virtuoso, which he would use to modify several components of a neural stimulation circuit. Generally, he changed width values of certain transistors and resistance values of certain resistors, with the end goal being to produce a biphasic pulse (positive and negative values) with an amplitude of about 1 mA. In practice, this pulse would be the stimulation current that would flow into the neurons at the stimulation points of the previously designed electrodes. By the end of the week, Alejandro was able to produce the desired waveform (in simulation), with an amplitude of almost exactly 1 mA and very minor noise affecting said waveform.
The beginning of Alejandro’s fourth week in Seoul was a slam dunk, as he played some evening basketball on both Monday (with his three roommates) and Tuesday (with one of his roommates and an SNU basketball club). He hadn’t played in months, so this felt great! The rest of the week was uneventful until Saturday; on Saturday, Alejandro took a trip to the Gwanghwamun area, where he started walking along the well-known Chonggyecheon Stream. He walked for a while before coming across Dongdaemun, an area that featured several shopping malls and a park area. He walked through a couple of the malls and enjoyed an iced latte before heading out, towards yet another, even better known shopping area: Myeongdong. He explored the streets of Myeongdong, nearly buying some dinner from a street vendor before realizing he didn’t have enough cash, and finished the night by going to the top of a shopping building adjacent to the main shopping area (to get a good view of the place). On Sunday, he explored the COEX mall in eastern Seoul with William, enjoying another iced latte before buying a new shirt at one of the stores there. The most astounding (and beautiful) part of the mall was by far the humongous library area, with bookshelves towering over Alejandro’s head; he’d never seen anything like it before! Alejandro had an enjoyable fourth week and weekend in Seoul, and is eagerly looking forward to his trip to Japan next weekend!