Department of Computer Science and Technology, Tsinghua University, Beijing 100084, China;
Department of Computer Science and Technology, Tsinghua University, Beijing 100084, China;
Department of Computer Science and Technology, Tsinghua University, Beijing 100084, China;
Department of Computer Science and Technology, Tsinghua University, Beijing 100084, China;
data mining; cluster analysis; k-means algorithm; parallelism;