Name the author who published the paper on Uplink system and has the name Yangyi.
Which author named Liu published the paper on Uplink system?
SELECT DISTINCT ?answer WHERE { <https://dblp.org/rec/journals/spl/LiuWZXS16> <https://dblp.org/rdf/schema#authoredBy> ?answer }
<https://dblp.org/rec/journals/spl/LiuWZXS16>