In Seoul, the capital, restaurants are busy and supermarket shelves are full, and he's noticed no overt movements of troops or military equipment through the streets. The spring weather feels like Philadelphia, he said, warm one day and cool and rainy the next.
Oh, who lives with his wife and two daughters in Blue Bell, pressed his extended family members in South Korea for signs of worry or fear, but said their reaction to the rising tension has been a collective shrug. They've been through this before. "The only difference is that there's a new leader in North Korea, and it remains to be seen how he acts. But they're not particularly concerned."
It's the rest of the world that's wary.
North Korea told foreigners this month to consider leaving South Korea because the peninsula was on the brink of nuclear war. American officials saw that as bombast, but on Thursday, a new Pentagon intelligence assessment concluded that North Korea was capable of building a nuclear weapon that could be delivered by a long-range missile.
Under the leadership of untested, 30-year-old Kim Jong Un, the North has threatened to launch a nuclear strike against the United States and South Korea, has cut off its direct phone link to the South, and has scrapped the 1953 agreement that ended the Korean War. President Obama has warned that the United States will take all necessary steps to protect itself.
Bellicosity from North Korea is nothing new, said Maria Toyoda, an East Asia specialist in the political science department at Villanova University, but fresh risk lies in potential miscalculations by any of the countries involved.
"Certain actions might be taken as more provocative than the actors intend," she said. "It's still very, very dangerous."
Oh teaches in Drexel's mechanical engineering department and is director of the Drexel Autonomous Systems Lab, which develops and works with advanced robots. He's been a fellow at the Naval Research Lab and at the NASA Jet Propulsion Lab, furthering his research in vision-based robot controls and robot hands.
In Korea, he leads Drexel's international research collaboration with the Korea Advanced Institute of Science and Technology (KAIST), a global university in Daejeon, about 90 miles south of Seoul. The cooperative offers Drexel students the chance to work on robots in a KAIST research lab, in a country where mechanical and computer sciences are viewed as economic-growth engines for new products and services.
Oh, born in Philadelphia to parents who emigrated from South Korea, travels to Korea two to four times a year. This trip has been different in that his friends and family in the United States are nervously following the news.
"They're shocked that I'm here," Oh said.
He reassures them that he's fine. And unruffled.
"It's not just me," he said. "It's everybody around me. . . . Things seem completely normal."
Contact Jeff Gammage at 610-313-8205, firstname.lastname@example.org, or on Twitter @Jeff Gammage.