TOKYO -- Chinese companies have surged ahead of their U.S. counterparts on a Nikkei ranking of the top 50 patent filers for artificial intelligence over the past three years, expanding their presence in the world's most prominent high-tech battleground.
In the three years between 2016 and 2018, China more than doubled the amount of companies in the top 50 to 19 - up from eight in the previous three-year span.
