Laser 3D scanning technology rapidly acquires point cloud data of target surfaces, including spatial point coordinates that describe the geometric features of the target and laser reflectance intensity that characterizes the material’s reflectivity. The application of automatic semantic segmentation techniques for 3D point clouds in geological exploration research lays the foundation for depicting regional geological features. To demonstrate the recent advancements of 3D laser scanning technology in large-scale semantic segmentation within geological scenarios, firstly, photogrammetry and LiDAR as two methods for acquiring 3D point clouds were compared, highlighting the advantages of LiDAR in terms of accuracy, versatility, and insensitivity to lighting conditions. By elucidating the principles of lithological semantic segmentation, a comprehensive review and summary of recent methods based on geometric or intensity features were provided. Common large-scale point cloud datasets and evaluation metrics were introduced, and the segmentation performance of different algorithms was compared. Finally, the limitations of existing methods were summarized, and future research directions for lithological semantic segmentation tasks were outlined.

Due to the unique challenges of deep underground mining environments, such as frequent geological disasters like roof fall, rock bursts, and water inrush, there is a high demand for enhanced safety and stability in mines. The use of downward roadway backfilling methods has shown significant effectiveness in controlling ground pressure activities and rock layer movement. In light of this, the Chambishi Copper Mine in Africa was selected as a case study. Initially, a digital structural plane identification system was employed to conduct a detailed analysis of the ore body structural planes. The findings indicate that the development of structural planes in deep ore bodies significantly impacts the safe extraction of minerals. The high density and narrow spacing of these planes increase the fragmentation of the rock mass, elevating the risk of roof fall and instability in mining areas. Additionally, numerical simulations were performed to study the mechanical behavior and deformation characteristics of the deep zones of the Chambeshi Copper Mine. By optimizing the structure and strength of the bearing layers, the stability of the mining area can be effectively controlled. The simulation results demonstrate that well-structured bearing layers are capable of withstanding the pressure from overlying rock strata, ensuring higher stability in the mining areas. These research outcomes provide effective strategies for the safe extraction of minerals in deep mines, particularly in high-risk geological environments. Adaptable mining methods and safety measures were proposed, which were of significant importance for enhancing the safety and efficiency of deep mining operations.

In order to solve the technical problem of insufficient reliability and life of rotary seal under the coupling effect of high pressure and high speed and medium corrosion, experimental research on rotary lip seal was carried out, a high-speed rotary lip seal test bed with pressure was designed and built, leakage and friction torque characteristic tests of lip seal were carried out, simulation calculation of lip seal was carried out, and a new type of seal with low friction coating was innovatively proposed. The temperature rise and torque comparison test of traditional seal and spraying new seal at different speeds were carried out. The experimental results show that the lip spraying tetrafluoroethylene (PTFE) material can effectively reduce the temperature rise of the seal. When the rotational speed increases by 1 000 r/min, after reaching the heat balance temperature, the temperature rise of the spray lip seal is 2.4 °C lower than that of the traditional lip seal. Under the pressure condition, the temperature of the coated lip seal is about 3.48 °C lower than that of the traditional lip seal. Under the condition of high speed and poor lubrication, the temperature of the spray lip seal is about 4.61 °C lower than that of the traditional lip seal, but the sealing torque increases by about 0.03 N·m. The sealing performance is evaluated from two aspects of sealing temperature rise and sealing friction torque, which provides theoretical support for solving the technical problems of high parameter rotary seal.

In order to analyze the influence of evolution of the dominant order of wheel polygonal wear on the vibration response of the train-bridge coupling system, the key influencing factors and evolution patterns of the dominant order of polygon wear were summarized first. Meanwhile, the coupled dynamic model of the train-bridge system was established by utilizing a combined simulation approach with ANSYS and SIMPACK. Subsequently, the impact of evolution of the dominant order of wheel polygonal wear on the vibration response of the train-bridge coupled system under different operational mileages, train operating speeds, vertical stiffness of fasteners, and variations in wheel diameter, was explored. The research results indicate that the evolution of the dominant order of wheel polygonal wear significantly affects the dynamic response of the train-bridge coupled system. In general, when the wheels experience high-order polygonal wear, the lateral and vertical accelerations at the mid-span of the bridge increase significantly. Moreover, the wheel-rail force and derailment coefficient also increase significantly, with the train wheels experiencing momentary bouncing. This has an impact on both the quality of high-speed train operation on the bridge and the safe operation of the bridge structure, necessitating timely wheel re-profiling.

Remote sensing image target detection is one of great significance in military reconnaissance, intelligent agriculture and other fields, especially small target detection has been gaining continuous attention. However, small targets in remote sensing images face the problems of insufficient feature information and difficult detection, which have become the biggest obstacles plaguing the development of remote sensing applications. To this end, the you only look once-hybrid feature(YOLO-HF) algorithm was proposed, which introduced a hybrid attention mechanism of channel attention and self-attention in the network of the traditional YOLOv7 model to extract the target’s deep features, and fused the shallow and deep features to increase the richness of local features; to further strengthen the attention to the global information, a global attention mechanism was added for the small-scale targets after the extraction of the features, to achieve the ability of global feature expression enhancement. In order to avoid that the traditional loss function was sensitive to the positional deviation of small targets, which leaded to poor detection effect, a new metric was selected for use, which was embedded into the computation of the bounding box loss function, so as to accelerated the convergence of the loss function and realized the enhancement of the detection accuracy of small targets. The experimental results show that compared with the traditional YOLOv7 algorithm, the proposed algorithm shows superiority on both RSOD and NWPU VHR-10 datasets, and in particular, the mean average accuracy on RSOD dataset is improved by 2.90%, and the mean average accuracy on NWPU VHR-10 dataset realizes an improvement of 3.61%.

In order to cope with the rapid recovery and growth of air passenger flow and the uncertainty of passenger group structure and consumption behavior, and to give full play to the role of aircraft parking stands resources in improving non-aeronautical revenue, an optimal allocation model for aircraft parking stands based on the maximization of flight route commercial value was established. Firstly, the game theory combinatorial weighting method was used to correct the influence of subjective factors on the evaluation results. Then, the commercial value of aircraft parking stands and flight routes was quantitatively ranked by the VlseKriterijumska optimizacija I kompromisno resenje(VIKOR) algorithm, which could eliminate the mutual influence of multiple indicators. Finally, a trunk airport in northern China was used as an example to verify the feasibility of the method. The results show that three evaluation indicators of commercial value of flight routes are significantly correlated with the per customer transaction at boarding gate and commercial concentration zone, including departure time, dwell time and daily average passenger volume. By reasonably matching flight routes and parking stands based on commercial value, the commercial value of boarding gate and commercial concentration zone can be increased by 9.4% and 6.2% respectively. Therefore, introducing the commercial value of flight routes into the traditional aircraft parking stands allocation model has important practical application value for increasing airports non-aeronautical revenue.

A lightweight and efficient two-stage video flame detection algorithm was designed to address issues of high false positive rates, poor adaptability, and low efficiency in complex scenes. In the first stage, an improved adaptive Gaussian mixture model (AGMM) was employed for rapid background modeling of video image sequences. Suspicious candidate regions were extracted from the sequences by leveraging the flickering and surging characteristics of flames. In the second stage, a residual deep normalization and convolutional neural network (ResDN) was used to discriminate these suspicious candidate regions. A simplified residual block was introduced to replace the original convolutional layers for a lightweight design, enabling accurate flame detection and localization. Compared with traditional classification algorithms, the proposed two-stage video flame detection algorithm effectively overcomes environmental interference in complex scenes, rapidly and accurately identifies flames, and demonstrates higher detection rates and adaptability.

To explore the formation mechanism of safety working style among flight cadets, a hypothetical model was constructed based on the theory of planned behavior, incorporating organizational safety culture as an extended variable. Six questionnaires, including behavioral attitude, subjective norms, perceived behavioral control, behavioral intention, safety working style and organizational safety culture, were compiled and distributed to 160 flight cadets. The feasibility of the theoretical model was analyzed through direct path effects, indirect path effects, and moderation effect analysis. The results indicate that the behavioral intention of flight cadets has a significant positive impact on their safety working style. Behavioral attitude, subjective norms, and perceived behavioral control influence safety working style primarily through behavioral intention. Additionally, subjective norms and perceived behavioral control can indirectly enhance behavioral intention through behavioral attitude, ultimately leading to a positive impact on safety working style. Furthermore, organizational safety culture plays a positive moderating role in the impact of behavioral intentions on flight cadets’ safety working style. These findings give new perspectives that it is significant to enhance flight cadets’ strong sense of safety responsibility, impose strict adherence to regulations and foster the integration of safety culture within civil aviation institutions which could effectively elevate their safety working style and ultimately ensure flight safety.

Microbial induced calcium carbonate precipitation (MICP) technology is an emerging green reinforcement technology for geotechnical engineering, which has a good application prospect in the reinforcement of loess slopes. The reinforcement of loess by MICP is affected by a variety of factors, in addition to the external environment, material properties and reinforcement methods and other factors, the calcium source, the concentration of binder, the age of the maintenance and the maintenance methods also play a decisive role in the microbial reinforcement of loess. The loess in Longxi area was taken as the research object, bacillus subtilis-induced calcium carbonate precipitation technology was adopted to consolidate loess, and a comparative experimental study on the shear strength of MICP-consolidated loess under the conditions of different calcium sources, binder concentration, age of maintenance and maintenance methods was carried out. The results show that the MICP technology is more effective in consolidating loess specimens when the calcium source is calcium chloride, the binder concentration is 1.0 mol/L and the specimens are cured for 7 d. The cohesion and internal friction are increased by 4.95 and 1.34 times, respectively, compared with the vegetal loess soil. The research results have certain reference value for the roadbed reinforcement and slope management in the Loess Plateau area.

In order to improve the traffic efficiency of aircraft routes in areas affected by strong convective weather and optimize the diversion path of aircraft under the influence of strong convective weather, a multi-objective diversion path planning method based on the non-dominated sorting genetic algorithm III(NSGA-III) was proposed. By constructing a flight environment model and delineating flight restricted areas according to airspace conditions, and on this basis, focusing on the impact of strong convective weather in the area where the aircraft was diverted, the aircraft operation cost was the lowest, the diversion angle was the smallest, and the non-linear coefficient was the smallest, with the goal of minimizing the impact of weather, using NSGA-III to comprehensively considered factors such as safety and economy and other factors, a multi-target diversion plan for a certain airspace route under severe convective weather was carried out, and simulation analysis was conducted. The research results show that NSGA-III can comprehensively consider the four proposed goals and calculate multiple effective alternative diversion paths. Under the conditions of selecting two diversion points and taking into account the economy and rationality of the operation while ensuring the safe operation of the aircraft, a total of 91 alternative routes are available.