The disruption recovery is regarded as a crucial role in the operation of freighter airlines. To expand the application scenarios of the freight flight network, elements such as mandatory nodes and external arcs were introduced to enhance the applicability of the network. In general, aircraft and cargo were defined in separate networks and are recovered using a sequential solving method. To explore the correlation between each research object and to complete each recovery action, the entity flow was defined to integrate different types of entities in the same network. To solve the problem of crew recovery, constraints such as crew duty and flight qualifications were added to the model, and a mixed integer linear programming model was constructed based on an improved flight network. This model can achieve integrated recovery of aircraft, cargo, and crew. To accurately evaluate the capacity constraints of the cargo aircraft, a unit load device was used to represent the volume of cargo and to improve the relevant models of capacity constraints. An entity aggregation approach was employed to reduce the number of entities to control the model complexity. The model evaluation was performed using operational data provided by a small freighter airline. The results show that the recovery solution causes a 42% reduction in the delay time. In the subsequent simulation experiments, six different disruption scenarios were established for two freighter airlines with multiple fleets. As the disruption rate increases, medium freighter airlines adopt the strategy of re-routing aircraft and rescheduling crew, while large freighter airlines focus on flight delays. The proposed integrated air cargo schedule recovery model based on an improved flight network can solve all the cases exactly in limited time, and the average error is 0.47%.

In order to realize the optimal design of rock-socketed pile foundation in mountainous area and effectively prevent the rupture of the rock, the compression mechanical behaviors and failure mechanisms of brittle rocks with different lithologies were experimentally and numerically investigated. Firstly, uniaxial compression tests were carried out on five kinds of brittle rocks based on the self-made compression testing system. Acoustic emission (AE) monitor system and digital image correlation (DIC) technology were used to discuss the characteristic parameters of AE signals during the crushing. Moreover, the characteristics of critical failure precursors and the evolution rules of damage failure of different rocks were obtained by using the nonlinear explicit finite element (FE) method. The experimental results were in good agreement with the corresponding FE ones. The results show that there are the obvious AE phenomena in brittle rocks during the uniaxial compression test, and the active degree of ringing count and accumulated energy can describe the internal damage of the specimens effectively. At the initial stage of the compression, there is no obvious crack on the rock surface. However, more cracks appear on the surface of the specimens with the increase of the compressive stress. The specimens are destroyed instantaneously when the compressive stress reaches the peak stress, and no new cracks are generated. The distribution and evolution of local strains can intuitively predict the breeding and expansion of new fissures. The research results provide theoretical reference for monitoring and warning of rock failure and foundation design of transmission line in mountainous area.

In deep oil and gas development, it is difficult to drill targeted with traditional sliding drilling tools because of the increasing number of wells with complex structure. To help solve the problem of wellbore trajectory control in complex structural wells, a discontinuous directional rotary steerable structure was proposed. Moreover, a mechanical model of discontinuous directional rotary steerable bottom hole assembly(RSBHA) was established by combining the element division idea of finite element method and the continuous beam-column theory. The bit side force and dip angle of were calculated by compiling mechanics program. The effects of borehole geometry parameters, drilling parameters and drill assembly structure parameters on mechanical properties were analyzed. It is concluded that weight on bit and inclination of hole have little influence on bit side force, but the structural parameters of drill assembly have great influence. The research results provide theoretical premise for the optimization of RSBHA structure and drilling parameters, and provide mechanical support for accurate control of wellbore trajectory.

To enhance the efficiency of carbon monoxide (CO) emission control during drill-and-blast construction in high-altitude tunnels and to improve the working environment for personnel, a tunnel currently under construction at a high altitude was investigated. Utilizing the computational fluid dynamics simulation software Fluent, three factors were examined under forced ventilation conditions: the distance between the air duct and the tunnel face, the position of the air duct, and the varying elevations. To model the diffusion characteristics of harmful CO gases. The simulation results indicate that when the air duct is positioned too close to the tunnel face, vortices form, causing CO accumulation near the tunnel face, which is detrimental to the effective dispersal of CO from this area. Conversely, when the duct is positioned too far, the airflow loses a significant amount of kinetic energy before reaching the tunnel face, which also hinders the effective removal of harmful CO gases in the vicinity of the tunnel face. Optimal removal efficiency of harmful CO gases near the tunnel face is achieved when the air duct is placed at a distance of 25.2 m from the tunnel face and located at the top of the tunnel. This configuration significantly improves the working environment for personnel within a short period. Compared to plain regions, the distance between the duct and the tunnel face in high-altitude areas should be approximately 3 \sqrt{S} (S is the cross-sectional area of the tunnel) that of the plain regions. The trend of CO movement within the tunnel is generally consistent across different altitudes. As the altitude increases, the concentration of CO also increases, and the speed of CO movement within the tunnel decreases, necessitating longer ventilation times in high-altitude areas.

In order to ensure the regular and punctual operation of civil aviation transportation, the efficient aviation spare parts supply is the fundamental basis. However, the stochastic replenishment lead time and demand aggregates the uncertainty of spare parts supply. An original equipment manufacturer-orientated aviation industry supply chain location-inventory problem under an uncertain environment was investigated. A two-stage stochastic optimization model, including facility location, inventory control, production decisions, etc., was constructed to maximize the supply chain's profit. A novel robust optimization approach was proposed for a resilient supply chain network design under an uncertain environment. The results show that original equipment manufacturer facilities are more likely to establish double-sourcing and multiple-sourcing strategies with the upstream tier suppliers as the supply lead time and demand uncertainty increase and the on-hand inventory and average ordering quantity of tier suppliers increase accordingly. In addition, high uncertainty in spare parts supply and demand leads to declining profits in the aviation industry supply chain, which can be relieved by robust and resilient supply chain design and efficient inventory control. It is concluded that the optimal strategic and tactical decisions of the aviation industry supply chain in the context of supply and demand uncertainty provide an effective solution for the robust and efficient operations of the global aviation industry supply chain.

To enhance the long-term displacement prediction accuracy of landslides, the GCformer model was applied to landslide displacement forecasting, and a novel landslide displacement prediction approach grounded in the GCformer model was proposed. This methodology leveraged rainfall and displacement as input variables, utilized the GConv_msk module to capture the global information of the sequence, and combined a linear scaling technique of sequence length to efficiently extract data features. Concurrently, the PatchTST model was employed to automatically extract short-term and long-term signals from the sequence data, in order to obtain more comprehensive historical information and bolster the model's robustness and modeling capability. Finally, the landslide displacement monitoring data from Jinliuping Village and Yuanshitan Village in Huichuan County, Dingxi City, Gansu Province, were utilized for case validation. The findings demonstrate that the proposed model exhibits superior prediction accuracy and reliability. In comparison to the Autoformer model and the FEDformer model, the GCformer model is found to achieve the lowest error in both total displacement and vertical displacement.

Under the traditional design scheme, the design quantity of main girder of the bridge erector is redundant and there are many consumables, which will reduce the production efficiency, and the existing optimization methods have the problem of low convergence accuracy. An enhanced beluga whale optimization (EBWO) based on quadratic interpolation strategy was proposed, and lightweight design of main girder of the 600t bridge erector was carried out. Firstly, six test functions were applied to evaluate and compare the effectiveness of the beluga whale optimization (BWO), EBWO and three other prevalent optimization algorithms, focusing on their convergence characteristics. Then, a mechanical analysis was conducted on the bridge erector girder under the real loading conditions. An optimization model was established by combining bridge girder design specifications and mechanical requirements, and the cross-sectional area optimization of main girder of the bridge erector was carried out. The results show that EBWO has the enhanced stability and convergence characteristics. It is proved that the optimized main girder is reduced by 19.3%, and can meet the safety requirements.

The traditional particle swarm optimization (PSO) algorithm still has shortcomings in terms of performance and efficiency of cloud computing task scheduling, such as low local search efficiency and limited search accuracy, which often makes it difficult to find the global optimal solution and easily falls into the local optimal solution. To solve this problem, an improved particle swarm optimization task scheduling algorithm(IPSO) was proposed. Firstly, a opposition-based learning strategy was used to create a more homogeneous initial population and the Rate of convergence of this algorithm was enhanced. Secondly, in the particle update process, the sine cosine algorithm(SCA) was introduced to enhance the optimization ability of the particles and balance the two processes of global search and local development. Finally, a search behavior based on average fitness was added to further expand the search solution space to find better optimal solutions and prevent falling into local optima. Experimental verification was conducted on the CloudSim simulation platform. The experimental results show that the improved particle swarm algorithm has significant advantages in reducing the cost and maximum completion time of system tasks. In particular, when the number of tasks reaches 500, IPSO improves the total cost by 10%, 4.6%, 8.6%, 9.2%, 8.2%, 10.4% and 11.3% respectively compared with adaptive particle swarm optimization (AdPSO), sine cosine algorithm-particle swarm optimization (SCA-PSO), simulated annealing particle swarm optimization (SAPSO), enhanced phagocytosis genetic algorithm (EPGA), competitive crossover mechanism genetic algorithm (C2PGA), opposition based learning-particle swarm optimization (OBL-PSO) and PSO, and improves the maximum completion time by 34.1%, 27%, 41.7%, 28.5%, 21.6%, 50.3% and 54.8% respectively, which verifies the feasibility and effectiveness of IPSO in solving cloud computing task scheduling problems under different task scales.

Due to the complexity and variability of the marine environment as well as the complexity of the dynamic characteristics of the offshore stabilized corridor bridge in a series-parallel hybrid configuration, the analysis of the dynamic characteristics of the offshore stabilized corridor bridge in the working process has always been a key point and a difficult point in the related research process. To address this problem, firstly, the projection matrix and Jacobi matrix of each component of the bridge were derived based on the vector method and Kane's method, as well as the dynamic equations under the generalized coordinate system, and the overall explicit dynamics model of the bridge was derived by using the Kane's method and the principle of virtual work. Secondly, a joint simulation model of MATLAB and Adams was constructed based on Simulink and the simulated motion of the vessel was simulated by the MSS toolbox to simulate the ship's motion as an excitation for analysis. Finally, theoretical calculations and simulation analysis were carried out under two working conditions, with and without personnel and cargo transfer, to verify the correctness of the established model. Further, the effects of loads of different masses on the driving force of the strut chain were investigated, and the compensating effect of the sea-stabilised corridor bridge was analysed. The research results are of guiding significance for the development of the sea-stabilised corridor bridge and its application on real ships.

The evolution of submarine channels and their sedimentary units under a million-year scale is related to factors such as sediment supply, sea-level change, paleotopography and tectonic movements. However, the changing rate of sea level has not been deeply associated with the type, scale, and sand-body distribution of submarine channels and their surrounding sedimentary units. Taking the central Oligocene submarine channel in the northern Atlantic basin as an example, based on three-dimensional seismic data cube, seismic-facies characteristics of submarine channels with their sedimentary units were characterized. 90°-phasing transformation and stratal slicing techniques were used to depict the planar distribution of submarine channel with sedimentary units. Frequency spectral decomposition was used to analyze the evolution of sedimentary units and the distribution of sand bodies. The sedimentary model of submarine channels with changing rate of sea level at a million-year scale was established. The results indicate that from the early to late Oligocene, a composite system of sandy submarine channel-terminal fan, a composite system of sandy-muddy filled submarine channel-crevasse fan and a composite system of muddy submarine channel are developed in sequence. The mass transport deposits are always accompanied. Sedimentary evolution process is mainly controlled by global sea level and can be divided into a slow sea-level dropping period of early Oligocene, a rapid sea-level rise period of middle Oligocene and a rapid sea-level dropping period of late Oligocene. The slow sea-level fall is conducive to the transportation of coarse terrestrial clastics through submarine channels into the oceanic basin, which is an important prerequisite for the formation of sandy submarine channels, terminal fans and large associated mass transport deposits. Therefore, sand bodies are most developed in the lower Oligocene.