Seapahn Megerian Farinaz Koushanfar Miodrag Potkonjak Mani B. Srivastava Worst and Best-Case Coverage in Sensor Networks. 84-92 2005 4 IEEE Trans. Mob. Comput. 1 http://csdl.computer.org/comp/trans/tm/2005/01/h0084abs.htm db/journals/tmc/tmc4.html#MegerianKPS05