Zaiqing Li

Learn More
We describe the design steps and final implementation of a MIMO OFDM prototype platform developed to enhance the performance of wireless LAN standards such as HiperLAN/2 and 802.11, using multiple transmit and multiple receive antennas. We first describe the channel measurement campaign used to characterize the indoor operational propagation environment,(More)
We present eecient polynomial time algorithms that place bn=2c vertex guards which cover the surface of an n-vertex polyhedral terrain, and similarly, bn=3c edge guards which cover the surface of an n-vertex polyhedral terrain. The time complexity of both algorithms, dominated by the cost of nding a maximum matching in a graph, is O(n 3=2).
We present an optimal ¢´Òµ-time algorithm for the selection of a subset of the vertices of an Ò-vertex plane graph so that each of the faces of is covered by (i.e. incident with) one or more of the selected vertices. At most ÒÒ¾ vertices are selected, matching the worst-case requirement. Analogous results for edge-covers are developed for two different(More)
Visual density is an important index for the estimation of photographic film and visual photo. The development of biomedical image and macromolecule image needs high measurement uncertainty of visual density in spectrum characteristic. The ISO standard of visual density measurement conditions was modified in 2001. A series of equipments designed for(More)
  • 1