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In order to improve the efficiency and precision of underground drill pipe counting in coal mines, a coal mine underground drill pipe counting method based on the improved YOLOv8n model is proposed. The YOLOv8n-TbiD is established.The model can accurately detects and segments drill pipes in mine drilling rig working videos. The main improvements include the following points. In order to effectively capture the boundary information of drill rods and improve the precision of the model in recognizing drill rod shapes, the weighted bidirectional feature pyramid network (BiFPN) is used instead of the path aggregation network (PANet). To address the issue of drill pipe objects being easily confused with dim mine environments, Triplet Attention is added to the SPPF module of the Backbone network to enhance the model's capability to suppress background interference. In response to the small proportion of drill pipes in the image and the complexity of background information, the Dice loss function is used to replace CIoU loss function to optimize the segmentation processing of drill pipe objects in the model. The method uses the YOLOv8n-TBiD model to segment the drill pipe and its mask information. A drill pipe counting algorithm is designed based on the rule that the mask area of the drill pipe decreases during drilling and suddenly increases when a new drill pipe is installed. The working video of the drilling rig in the fully mechanized working face is selected, in order to conduct experimental verification of drill pipes counting method based on YOLOv8n-TBiD model. The experimental results show that the mean average precision of the YOLOv8n-TBiD model for detecting drill pipes reaches 94.9%. Compared with the comparative experimental models GCI-YOLOv4, ECO-HC, P-MobileNetV2, YOLOv5, and YOLOX, the accuracy increases by 4.3%, 7.5%, 2.1%, 6.3%, and 5.8%, respectively, and the detection speed increases by 17.8% compared to the original YOLOv8n model. The proposed drill pipe counting algorithm achieves precision of 99.3% on video datasets from different underground coal mine environments. more...

Objective The mountainous and hilly areas of western Zhengzhou City have a complex geological environment, affected by rainfall and human engineering activities. Geological hazards such as collapses, landslides, and debris flows occur frequently. In particular, the “7·20” extreme rainstorm that occurred on July 20, 2021 caused many geological hazards, resulting in heavy casualties and huge economic losses. Therefore, analyzing and summarizing the development characteristics of geological hazards and conducting a risk assessment is necessary for this region. At present, the risk assessment of geological hazards is mainly conducted using a single method that has limitations including slightly low evaluation accuracy. In addition, an overall geological hazard risk assessment has not yet been conducted in the mountainous and hilly areas of western Zhengzhou City. Methods Based on the research and analysis of the geological environment background and the distribution characteristics of geological hazards in the study area, eight evaluation factors were selected: slope, landform, engineering geological rock group, elevation, distance from fault, distance from river, rainfall, and human engineering activities. The weighted information method which incorporates elements of the information quantity model and analytic hierarchy process, was used to evaluate the risk of geological hazards in the study area. Results The low-, medium-, and high-risk areas are 1387.14 km2, 1803.18 km2, and 1066.47 km2, respectively, accounting for 32.59%, 42.36%, and 25.05% of the total area, respectively. The medium- and high-risk areas are mainly distributed in the tectonic erosion medium-low mountains and loess hills in the central part of the four cities, the tectonic erosion medium-low mountains south of Dengfeng, and the loess hilly areas in northern Gongyi and Xingyang. The terrain has steep slopes and deep gullies, and the main stratigraphic lithology is clastic rocks intercalated with carbonate rocks, soft and hard rock layers, and loess. Fault structures are developed, and geological hazards are prone to occur under the action of inducing factors and are highly dangerous. The majority (93.11%) of geological hazards are distributed in medium- and high-risk areas, with hazard point densities of 0.1752 km−2 and 0.2869 km−2, respectively. The spatial distribution of geological hazard points is consistent with the geological hazard risk assessment results. The rationality of the evaluation results was assessed by a Receiver Operating Characteristic curve, yielding an AUC value of 0.868. The evaluation accuracy met the requirements for hazard assessment. Conclusion Geological hazards have the largest information value in the range of >40° slopes loess hilly landforms, loess engineering geological rock groups, and 24-h maximum rainfall of 500–550 mm. The risk of geological hazards is positively correlated with distance from faults and water systems — the closer the distance, the higher the risk. The risk of geological disasters in the study area is controlled by the terrain slope and landform and is closely related to the lithology of the formation, which is an important factor in inducing geological disasters. The weighted information method, which has high accuracy and rationality, was used to evaluate the geological hazard risk. Significance The results of this study can provide a basis and technical support for geological hazard prevention and management in the mountainous and hilly areas of western Zhengzhou City and serve as a valuable point of reference for urban planning and infrastructure geological hazard risk assessment in the study area. more...

Objective: To explore the feasibility of Lisfranc ligament reconstruction with autogenous tendon through biomechanical testing., Methods: Twelve fresh-frozen cadaveric lower limbs were prepared three sequential testing conditions: intact Lisfranc ligament (intact group), disrupted Lisfranc ligament (disrupted group), and Lisfranc ligament reconstruction (reconstruction group). Under fixing on the Bose mechanical test machine, three models were given 0-600 N axial loading in the neutral position and the plantar flexion of 30 degrees according to the speed of 10 N/s, every 100 N load with a 1-minute interval. The medial cuneiform (C1) and the second metatarsal (M2) base displacement and the foot transverse arch height were recorded under different loads., Results: In the neutral position and the plantar flexion of 30 degrees, C1-M2 displacement and foot transverse arch height showed an increasing trend with increased load under 0-600 N axial loading. There were significant differences in C1-M2 displacement variation in 2 positions among groups (P < 0.05). In disrupted group, the C1-M2 displacement variation in neutral position was significantly lower than that in plantar flexion of 30 degrees (t = 7.392, P = 0.000). In the neutral position, the foot transverse arch height variation in the disrupted group and the reconstruction group was significantly higher than that in the intact group (P < 0.05), but there was no significant difference between the disrupted group and reconstruction group (P > 0.05)., Conclusion: Lisfranc ligament reconstruction with autogenous tendon can reduce the C1-M2 displacement variation and stabilize Lisfranc joint to a certain degree. Reconstruction of both dorsal ligament and Lisfranc ligament will not improve the buffering capacity. The C1-M2 displacement variation in the plantar flexion of 30 degrees is more obvious than that in neutral position, so it is helpful to improve clinical diagnosis of occult Lisfranc damage. more...