Zhu Si-Feng, Liu Fang, Chai Zheng-Yi, Qin Yu-Tao, Wu Jian-She. Simple harmonic oscillator immune optimization algorithm for solving vertical handoff decision problem in heterogeneous wireless networkJ. Acta Physica Sinica, 2012, 61(9): 096401. DOI: 10.7498/aps.61.096401