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Seismic exploration technologies developed in coal mines and oil fields are basically the same but with certain differences. Safety is one of the key issues in coal mining in China due to unexpected fatal accidents of underground work. Most of these accidents were derived from a geologic anomaly, such as minor faults, subsidence columns, gobs (old coal mining areas), and caving zones (collapse areas), which are of fundamental importance to prevent mining losses from coal mining risk caused by flooding accidents, broken coal beds, added fissures, and accumulated gas. In addition, minor faults also have significant influences on tunnel design in mechanical mining. Above all, accurate identification of these factors is critical in coal mining. We have focused on a coal mine located in eastern China with a burial depth from 500 to 1000 m and a smaller area of less than [Formula: see text]. Using high-precision 3D seismic data and seismic attribute analysis techniques, such as variance, curvature, ant tracking, etc., satisfactory results have been achieved in identifying minor faults, subsidence columns, coal tunnels, and gobs. Verified with actual coal mining, up to 85% of the predicted minor faults with a fault throw within 2–3-m match actual minor faults, and the predicted subsidence columns, coal tunnel, and gob were in perfect agreement with the real-world situation.

In order to compensate the threshold voltage variation while obtaining the sufficient data charging time, the AMOLED compensative pixel circuit needs to be driven by multi-pulse signals which have continuous high/low level pulses. By using traditional gate driver on array (GOA) with half duty-cycle delay of clock signals, the area of shift register is doubled, increasing the bezel width and power consumptions. In this paper, novel compact integrated gate driver circuit architectures for AMOLED pixel compensation purpose are presented. Outputs with programmable pulse width and number are achieved in these gate driving circuits without consuming extra large areas. Inner feedback technique is adopted in GOA circuit for leakage current cutting of depletion mode IGZO TFTs. The simulation result shows that these circuits work successfully with maximum ±3V threshold voltage shift. These GOA circuits can be used for internal or external Vth compensation techniques of AMOLED panel.

Summary The collapse column and gob of a coal mine destroy the continuity of coal seams, influence the face layout of mining, and create a significant hazard for mining staff. The collapse column creates water channels for underground water to flow from the Ordovician limestone. Similarly, the gob of the coal mine is usually filled with very large volumes of ground water. Currently, there are no good methods to effectively identify these subsurface features. This paper presents an effective method for identifying collapsed columns, coal mine gobs, and other anomalous geological bodies using conventional seismic migration profile interpreting method integrated with some attribute analysis methods. 3D seismic data from HuaiNan mining area in China were used to illustrate the technique for identifying the collapse column and the gob of a coal mine. Locating the collapsed columns and gobs is important for designing coal mine working areas.