Yao Zhou

Zhonghe Zhou

Photo: Liwang Jin, Xinhua News Agency. Zhonghe Zhou began his career at Nanjing University in 1982, studying paleontology and stratigraphy. He received a Master of Science from the Graduate School of the Chinese Academy of Sciences (CAS), after which he went on to work at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) CAS in Beijing, before attending graduate school at th...

Odd Yao-Yao Graphs are Not Spanners

It is a long standing open problem whether Yao-Yao graphs YYk are all spanners [26]. Bauer and Damian [4] showed that all YY6k for k ≥ 6 are spanners. Li and Zhan [23] generalized their result and proved that all even Yao-Yao graphs YY2k are spanners (for k ≥ 42). However, their technique cannot be extended to odd Yao-Yao graphs, and whether they are spanners are still elusive. In this paper, w...

Jizhong Zhou

Zhou, H

A Simple Yao-Yao-Based Spanner of Bounded Degree

It is a standing open question to decide whether the Yao-Yao structure for unit disk graphs (UDGs) is a length spanner of not. This question is highly relevant to the topology control problem for wireless ad hoc networks. In this paper we make progress towards resolving this question by showing that the Yao-Yao structure is a length spanner for UDGs of bounded aspect ratio. We also propose a ne...