Wudi was a man of insight, ambition and the ability to use someone's specialty to his needs.
After Wendi and Jingdi's achievements, China's national power has reached its pinnacle. When Wudi ascended the throne, he focused on solving the threats of the Nomads from the north. Heavily employing the talents of the generals -- Huo Qubing , Wei Qing, etc, and with the help of Zhang Qian's Western trips, Wudi solved the threats of the Nomads in 30 years and brought China to become the sole ruler in the East Asian world.
Cai Lun was an eunuch during the reins of Han Hedi. He was a man of talents, insight and creativity. He was responsible for all of the manufacturing of machines in the imperial court. Things created by him were of good quality and exquisite. Hedi ordered him to look over the production of paper. After research and many experiments, Cai Lun was able to produce economic paper that was used in books at them time. After his death, people named this paper -- the paper of Cailun -- in an attempt to commemorate his achievements