The Japanese supercomputer K, pictured in June 2012 at the RIKEN Advanced Institute for Computational Science in Kobe, western Japan. The K computer is currently ranked No. 3 on a list of the 500 fastest supercomputers.
President Obama and his delegation stand Monday during a welcome ceremony with Ethiopia's Prime Minister Hailemariam Desalegn at the National Palace in Addis Ababa, Ethiopia.
Tiksa Negeri /Reuters /Landov
A supporter waves a Cuban flag in front of the country's embassy after it reopened for the first time in 54 years on July 20 in Washington, D.C. The embassy was closed in 1961 when U.S. President Dwight Eisenhower severed diplomatic ties with the island nation after Fidel Castro took power in a communist revolution.
Mark Wilson/Getty Images
President Obama and Kenya's President Uhuru Kenyatta onstage after delivering remarks at the Global Entrepreneurship Summit at the United Nations compound in Nairobi, on Saturday.
President Obama is hugged by his half-sister, Auma Obama, accompanied by Kenya's President Uhuru Kenyatta (right) as he arrives at the Jomo Kenyatta International Airport in Nairobi on Friday.
Iran's Supreme Leader Ayatollah Ali Khamenei delivers a sermon during morning prayers for the Eid al-Fitr holiday, marking the end of the holy month of Ramadan. He signaled his approval of the nuclear agreement with Western powers but reiterated that Tehran's policy toward the "arrogant" United States would not change.
President Obama joins comedian Bill Cosby and others to sing "Happy Birthday" to Sen. Edward M. Kennedy, D-Mass., on March 8, 2009, at The John F. Kennedy Center for the Performing Arts in Washington, D.C.
Haraz N. Ghanbari/AP