6WU L X, YANG K M, QI A W, et al. Information classification & management for IVlGIS ard digital mine[A]. Prec. 1st Int. Syrn. on Digital Earth[C]. Fleijing: Science Press, 1999.99- 1004.
7BAETEN J C M, MIDDELBURG C A. Real time pmcem algebra with time- dependent conditions[J]. Logic and Algebraic Programming,2001 (48) : 1 - 38.
8WAN Y C, DUK D L. Real time multi - channel gas leakage monitoring system using CPLD chip[J ]. Sensor and Actuators B,2001 (77): 186 - 189.
10LIU F Q, YU H Z, O.IANG J S. Research on the K J52 multimedia safety rnonitoring system in coal mine[A]. 29th Int. Syrup. on Ccmaputer Applications in Minerals Industries [C]. The Netherlands: Balkema,2001. 573 - 576.
