To address the problems of high scene complexity, difficult recognition, and high false detection rate in detecting abnormal behavior of object passing through subway station barriers, a detection method is proposed that data fusion based on light detection and ranging（LiDAR）and camera sensors．A voxel difference algorithm is used to process LiDAR point cloud data, divide the detection area into voxel units, and establish a trigger mechanism for object passing．An object locking algorithm is employed to fuse data collected by LiDAR and cameras, supplementing depth information of human key points and locking onto target of object passing through barriers．The spatial-temporal graph convolutional network（STGCN）is lightweight-modified to reduce model complexity and computation time．A temporal trend attention（TTA）model is introduced to enhance the extraction of spatial-temporal feature changes in postures of object passing through barriers, forming the TTA-STGCN model to calculate the confidence of behavior occurrence of object passing through barriers．Collecting data of object passing through barriers through laboratory simulation and on-site in subway stations．Detection performance evaluation metrics are established．Training, validation, and testing of STGCN, STGCN-MIN, and TTA-STGCN models are conducted．In the training phase, the accuracy of the TTA-STGCN model improved by 3.73% compared to the first two, the overall loss decreased by 66.00%．In the validation phase, the accuracy of the TTA-STGCN model improved by 3.89% and 0.68% compared to the first two respectively, the overall loss decreasing by 58.95% and 58.48% respectively．In the testing phase, the accuracy of the TTA-STGCN model improved by 3.15% compared to the first two, the overall loss decreasing by 42.85% and 44.40% respectively．Field experiments show that the TTA-STGCN model' s accuracy improved by 2.99% and 3.49% compared to STGCN-MIN and STGCN models respectively, precision improved by 2.28% and 1.31% respectively, recall improved by 4.30% and 6.45% respectively, and F1 score improved by 0.033 5 and 0.040 4 respectively, demonstrating that the TTA-STGCN model significantly enhances the detection accuracy of behavior of object passing through barriers in specific subway station scenarios．

To enhance highway bus traffic safety and reduce accident rates, data from 2, 320 samples are collected, including bus accident frequency, traffic volume, road characteristics, weather conditions, and holiday proportions, from three highways in eastern China．Accounting for accident heterogeneity, Poisson-lognormal（PLN）, random parameters Poisson-lognormal（RP-PLN）, and random effects Poisson-lognormal（RE-PLN）models are established．The Bayesian method and Markov chain Monte Carlo simulation estimate the posterior distribution of model parameters．The modeling results quantitatively assess the impact of various factors on highway bus accident frequency．Findings indicate that the RP-PLN model exhibits superior goodness-of-fit compared to the PLN and RE-PLN models．Road segment length, traffic volume, and holiday proportion show positive correlations with accident frequency, while temperature, relative humidity, and visibility demonstrate negative correlations．Holding other factors constant, a 1% increase in road segment length and traffic volume increases accident frequency by 0.90% and 0.62%, respectively．A one-unit increase in holiday proportion increases accident frequency by 8.30%．Conversely, a one-unit increase in temperature, relative humidity, and visibility reduces accident frequency by 5.72%, 8.82%, and 6.55%, respectively．

To analyze the dynamic characteristics and driving mechanisms of tourism transportation carbon emissions in Fujian-Guangdong-Hainan coastal regions, based on the panel data of Fujian-Guangdong-Hainan coastal regions from 2012 to 2022, the carbon emissions of tourism transportation by four modes of transportation, namely road, railway, civil aviation and waterway, are calculated using the bottom-up approach, and their dynamic evolution trends are examined．Combining the Kaya identity and the logarithmic mean Divisia index（LMDI）decomposition method, evaluates the impact and contribution rates of six driving factors：tourist scale, tourism industry contribution, tourism consumption level, tourism transportation intensity, energy intensity, and energy structure．The results show that from 2012 to 2022, tourism transportation carbon emissions in Fujian-Guangdong-Hainan coastal regions initially increased and then decreased overall．Aviation is the primary source of tourism transportation carbon emissions, accounting for 82.00% of the total．Per capita carbon emissions from tourists decline annually, with an average annual growth rate of -13.80%, indicating that carbon emissions grow at a slower rate than tourist numbers．The main factors promoting tourism transportation carbon emissions are tourist scale, tourism industry contribution, energy intensity, and energy structure, with cumulative contribution rates of 91.88%, 252.63%, 356.79%, and 27.75%, respectively．The key factors inhibiting carbon emissions growth are tourism consumption level and tourism transportation intensity, with cumulative contribution rates of -87. 01% and -542. 04%, respectively．

To predict the stability conditions of the support structure and achieve effective early warning, finite element software MIDAS CIVIL is used to model the pin-supported disc-type supports of the bridge, simulating the response characteristics of the support structure under single-point settlement and regional settlement conditions．Using in-situ testing methods on the bridge, a comparative analysis is conducted between the simulated data and the actual measurement data of the support deformation, demonstrating the feasibility of using angular change thresholds to monitor the preloading and pouring processes, and acquiring the deformation patterns at critical positions of the supports．The results show that the deformation data measured by the gyroscope closely match the simulated data, and the angular change threshold for construction process monitoring is feasible．Insufficient foundation bearing capacity leads to three different settlement conditions：first, when the single-point foundation bearing capacity is insufficient, forced displacements are applied to the four corner support rods at the bottom plane of the middle part of the support structure, resulting in significant angular changes at four measurement points, but none exceeds the warning threshold; settlement occurred at the position where the largest reaction force from the support is applied at the bottom of the support; second, when the foundation bearing capacity is insufficient in certain areas, forced displacements are applied to the middle, left, and right parts of the support structure, significantly affecting the key monitoring sections, with noticeable changes in local structural displacements; the angular changes remain within the permissible thresholds, and the reduction rates of displacement and angle during the pouring condition show minimal variation; third, when the foundation bearing capacity at the bottom of the members where each measurement point is located is insufficient, simultaneous node displacements are applied to the bottom nodes of the monitoring sections, with major settlement occurring in the regions around the bottom of the measurement points; the angular threshold increases with the increase in load, validating the effectiveness of the settlement identification and early warning method based on angular thresholds．

To study the degradation mechanism of the mechanical performance of the main girder of a prestressed concrete cable-stayed bridge under the action of vehicles and external factors, the cable-stays are equivalent to elastic supports．Using an equivalent three-span continuous beam as the basic structure, the analytical expressions for the degradation laws of cable force, bending moment, and deflection of the main girder after damage are derived．The research results indicate that after damage to the main girder, the cable force near the damaged area of the main girder increases; the changes in bending moment and deflection of the main girder primarily occur in the damaged span．Case studies validate the effectiveness of the theoretical calculation results on the degradation of the mechanical performance of the prestressed concrete cable-stayed bridge after damage to the main girder, which can be used for assessing the mechanical performance of the main girder after damage．

To analyze the stress conditions of bridge deck panels with different stiffener forms in steel box girders, the software ANSYS is used to establish a comprehensive model and a spatial shell local model for a single box double-chamber continuous steel box girder with a span of（32+40+32）m．The effects of the main girder system and bridge deck system are obtained, and a comparative analysis is conducted on the structural effects of commonly used open section（inverted T-shaped）stiffeners and closed section（U-shaped）stiffeners in bridge deck panels．The results indicate that：1）The overall model reveals that the stress situation of the main girder system in the steel box girder, under basic combination effects and fatigue load effects, shows that the displacements and stresses of the bridge deck panels with inverted T-shaped stiffeners and U-shaped stiffeners are quite similar. 2）Under local vehicle load, the longitudinal and transverse stresses of the inverted T-shaped stiffener bridge deck panel are more than twice those of the U-shaped stiffener bridge deck panel; the maximum longitudinal stress of the inverted T-shaped stiffener is greater than that of the U-shaped stiffener, while the vertical shear stress is smaller than that of the U-shaped stiffener and is lower than that of the bridge deck panel; the transverse and vertical stresses of the U-shaped stiffener steel box girder web are significantly increased compared to the inverted T-shaped stiffener, with a maximum increase of about 3.5 times．In design, adjustments should be made to the stiffness of the longitudinal and transverse stiffeners to ensure balanced stress in all components; the local deformation trends of the bridge deck panels in the inverted T-shaped and U-shaped stiffener models are similar, but the local deformation of the bridge deck panel under the inverted T-shaped stiffener model is larger than that of the U-shaped stiffener model, approximately 1.2 times the displacement of the latter．

To reflect the actual state of the unsaturated three-phase medium of the subgrade, the subgrade is regarded as an unsaturated porous medium with incompressible solid and liquid phases, and a compressible gas phase．Based on the representation method of unsaturated porous media, considering the effects of inertia, viscosity, and mechanical coupling, a dimensionless one-dimensional wave equation for the unsaturated subgrade is established．Taking a type of non-homogeneous boundary as an example, the problem is transformed into an initial value problem of a second-order ordinary differential equation through boundary homogenization and the method of characteristic functions, and the state-space method is used to obtain the exact solution of the one-dimensional transient response of a single-layer unsaturated subgrade．The correctness of the results is verified through numerical examples．The characteristics of the one-dimensional transient response of the single-layer unsaturated subgrade under step and sinusoidal loads are analyzed．The results show that, unlike compressible saturated and unsaturated soils, there is only one type of compression wave in the incompressible unsaturated subgrade．As the liquid phase saturation increases, the wave speed and vibration amplitude of the compression wave decrease．The conclusion can provide a reference for the optimal design and disaster prevention of unsaturated subgrades under complex environmental loads．

To improve the comprehensive road performance of in-situ recycled asphalt mixtures, this study investigates the impact of the amount of rejuvenator on the performance of recycled asphalt based on rheological performance parameters such as rutting factor, creep stiffness, creep rate, and critical temperature difference．It proposes a method for determining the quality ratio of rejuvenator to reclaimed asphalt based on the relationship between continuous high-temperature grades and continuous low-temperature grades．This method balances the high-temperature and low-temperature performance of asphalt to define the quality ratio of rejuvenator to reclaimed asphalt．Based on the determined quality ratio, asphalt mixtures are prepared, and the high-temperature and low-temperature performance of these mixtures is compared with those determined by the penetration method for the same quality ratio of rejuvenator to reclaimed asphalt．The results indicate that as the quality ratio of rejuvenator to reclaimed asphalt increases, the rutting factor of recycled asphalt measured by dynamic shear rheology gradually decreases, the creep stiffness measured by bending beam rheology decreases, the creep rate increases, and flexibility improves．The quality ratio of rejuvenator to reclaimed asphalt determined based on continuous high-temperature and low-temperature grades results in a slight decrease in the high-temperature performance of the recycled asphalt mixture, but the water-saturated Marshall residual stability increases by 9. 4%, the freeze-thaw splitting tensile strength ratio increases by 7.9%, and the bending failure strain of the small beam increases by 5.5%, effectively balancing the high-temperature and low-temperature performance of the recycled asphalt mixture．

To investigate the road performance of high modulus asphalt mixtures（HMAM）in long-life pavement applications, high boiling point petroleum is incorporated into base asphalt to prepare high modulus asphalt binder（HMAB）．Penetration, softening point, brittleness point, and dynamic modulus tests are conducted to evaluate HMAB' s hardness, high-temperature stability, low-temperature crack resistance, and dynamic load response characteristics, demonstrating its modulus enhancement and performance advantages over conventional binders．Furthermore, dynamic modulus, moisture susceptibility, rutting resistance, and fatigue tests are performed on HMAM to assess its structural stiffness, moisture resistance, high-temperature rutting resistance, and durability, confirming its suitability for long-life pavement compared to conventional mixtures．Results indicate that HMAB exhibits significantly higher stiffness than conventional asphalt while maintaining comparable low-temperature performance．Under high-temperature conditions, HMAM demonstrates a 50% higher dynamic modulus, approximately 10% improvement in moisture resistance, twice the resistance to permanent deformation, and 5～10 times greater fatigue cracking resistance compared to conventional mixtures．

To address issues such as large volume, heavy weight, and low adsorption force of permanent magnetic wheel in wall-climbing robot, the design aims to reduce the wheel mass and increase adsorption force．Combining lightweight design methods, the magnetic disks on both sides of the permanent magnetic wheel are designed by structural optimization．Electromagnetic field simulation software ANSYS Maxwell is used to model and simulate the permanent magnetic wheel, obtaining the magnetic field line distribution．By reducing the magnetic material in areas with sparse field lines and increasing it in dense areas, the wheel's adsorption force is enhanced．Through adjusting the main structural parameters of the magnetic disk and simulating the adsorption force changes between the permanent magnetic wheel and ferromagnetic wall surface, the optimal structural parameters for maximum adsorption force are determined．Simulation and physical tests verify the adsorption force of the optimized magnetic disk．Results show that the magnetic disk mass is 232.53 g, reduced by 16. 24%; the simulated adsorption force between the permanent magnetic wheel and ferromagnetic wall is 487. 65 N, increased by 20.74%; 50 pull tests of the permanent magnetic wheel all exceed the simulated adsorption force, with an average of 493. 83 N．The results show that after structural optimization, the mass and adsorption force indicators of the permanent magnet rotor meet the design objectives．

To address the issues of unbalanced load and system nonlinearity in quadrotor unmanned aerial vehicles（UAV）attitude control, a LSTM-MPC strategy is proposed by combining the advantages of long short-term memory（LSTM）neural network and model predictive control（MPC）．LSTM neural network is used to predict attitude changes, enhancing the system' s ability to anticipate errors．MPC is employed as feedforward control to dynamically optimize control inputs．The combination significantly improves system control accuracy．MATLAB simulation experiment on quadrotor UAV attitude control with unbalanced load shows that：compared to MPC strategy, the LSTM-MPC strategy reduces the root mean square error of tracking expected values for roll angle, pitch angle, and yaw angle by 13. 33%, 12. 31%, and 11. 11% respectively; compared to fuzzy PID strategy, it reduces by 14. 05%, 25. 33%, and 23. 81% respectively．Flight test is conducted using a branded F450 quadrotor UAV platform carrying a 0. 6 kg load to test unbalanced load attitude control．The test result shows that the average errors between the actual output and expected values of the quadrotor UAV's roll, pitch, and yaw angles using the LSTM-MPC strategy are 3. 91%, 5. 31%, and 1. 10%, respectively, indicating that the LSTM-MPC strategy can effectively improve the flight stability of quadrotor UAV attitude control with unbalanced load．

To accurately simulate the regenerative braking conditions of micro electric vehicles, a regenerative braking test system model is developed using MATLAB/Simulink．The simulation analyzed regenerative braking performance and calculated the regenerative efficiency of the drive motor under forced braking and gentle braking modes．The results show that when the accelerator pedal opening reaches 95%, the regenerative efficiencies under forced and gentle braking modes are 60.3% and 14.6%, respectively, which align closely with the target values of 60.0% and 15.0%．Additionally, higher braking deceleration and longer regenerative braking duration lead to greater recovered energy．The forced braking mode of the drive motor can significantly increase regenerative energy, thereby extending the driving range of micro electric vehicles．