1Framework and key technologies of Internet of things for precision coal miningYUAN LiangColumn of Top-down Design of Mine Internet of Things1-72Design of on-line monitoring system for self-excited dedusterWANG Dongxue, LI Xiaochuan, WEI Tao, HU Haibin, XIANG WuAchievements of Scientific Research7-133Application of symmetrical component method in protection system of bolter-minerJIAO XiaofengAchievements of Scientific Research14-174Development trend of mine frequency converterZHU Yongping, XU XiaojianReview18-235Research status and prospect of shearer positioning technology on fully mechanized coal mining faceXIA Ting, LI Wei, WANG Chao, LI YuchenReview24-286Status and development direction of key technologies of gas telemetryHUO Yuehua, FAN Weiqiang, SUN YanyuReview29-337Application analysis of LoRa technology in mine wireless communicationHUO ZhenlongAnalysis Research34-378Roof stability analysis in No.3 coal seam of Panxie peripheralZHANG Yutong, LIU Qimeng, CAI Mengya, ZHAO Jin, YE Mei, ZHANG DandanAnalysis Research37-429Variability modeling of coal mine safety monitoring and control fieldYUAN Yaru, XIE Binhong, PAN Lihu, ZHANG YingjunAnalysis Research43-4710Theory and key technologies research on adaptive multi-antenna in coal mine tunnelHUO Yu, ZHANG Yi, XU Zhao, GAO MinAnalysis Research48-5311Mine TOA ranging method based on re-spread spectrum to WiFi signalSUN Jiping, JIANG EnsongExperimental Research53-5812Research on coal-bed image fractures identification based on fracture shape characteristicsLIU Yong, CUI HongqingExperimental Research59-6413Research of distributed multi-point laser methane detection systemTAN Kai, GUO Qinghua, ZHANG Yuanzheng, GOU YiExperimental Research65-6914Coal content recognition method of coal-rock mixture based on phase difference detectionHAN Nannan, CHENG Yuanxin, LIU Xiaowen, ZHAO Duan, WANG XinExperimental Research69-7315Design of closed-loop control system for hydraulic cylinder position of roadway supportWANG Fan, ZHAO JiyunExperimental Research74-7716Modeling and simulation of drum height adjusting system of shearerCHEN Jinguo, LIU Chunsheng, FAN Jianhong, ZHANG Yanjun, WAN FengExperimental Research78-8217Shearer position and attitude adjustment based on strapdown inertial navigation systemZHANG Qing, WANG Xuewen, XIE Jiacheng, PANG Xinyu, YANG ZhaojianExperimental Research83-8918Residual life estimation of components of hydraulic support in serviceZHAO Dongbo, LU Jingui, YAO Lingling, WANG JingtaoExperimental Research89-9319Application of travelling bogie in vane welding station of spiral drill pipeLAN Fei, WU ZhifengExperience Exchange94-9620Design of self-adaptive echo cancellerLI Wenfeng, WANG Xiaohui, SUN XiaoyeExperience Exchange97-100 