Statistical Methodology Commons^™

Research On Pavement Crack Segmentation Based On Swin-U, Wang Hua, Wang Liangcai, Xiong Feng, Hu Jing

Journal of China & Foreign Highway

To address the issues of overfitting,low computational speed,and insufficient target information extraction in pavement crack segmentation tasks,this study proposed a Swin-U network model based on the U-Net architecture.The model adopted the Swin-Transformer as the feature extraction module to enhance the model ’s fitting capability and enable more accurate crack feature extraction,thereby enhancing segmentation accuracy.Additionally,a stable loss function,Focal Loss,was introduced to improve the accuracy of target segmentation.Experiment results on a proprietary pavement crack dataset show that the Swin-U network model achieves pixel-level segmentation of crack images and significantly outperforms the traditional U-Net.On the test set,it improves the intersection over union and …

Long-Term Water P Ermeability Performance Of Asphalt Mixtures Under Wide-Scope Void Ratio, Chen Sanxi, Guan Hongxin, Yao Ming, Mo Zhiwei, Jiang Wangheng

Journal of China & Foreign Highway

In order to compare the water pe rmeability performance of asphalt mixtures with different void ratios after scouring and clogging,self-developed equipment was adopted to conduct vertical water permeability tests,dynamic water scouring-based water permeability tests,water pressure tests,and simulated clogging tests on semi-open-graded DK- 13 mixtures with void ratios of 9%,11%,and 13%,as well as open-graded PA- 13 mixtures with void ratios of 15%,17%,and 19%.The experimental results show that:① The water permeability performance of the asphalt mixture becomes better as the void ratio increases.The water permeability coefficient changes relatively small after the void ratio of the asphalt mixture reaches 15%,which is attributed to …

Research On Key Construction Monitoring Technology Of Long-Span Skewed Arch And Curved Beam Bridge, Xu Yufeng, Zhang Zhantao, Xie Yunfei, Li Zihui

Journal of China & Foreign Highway

As a new structure with sloping arch ribs and curved main beams,a skewed arch and curved beam bridge markedly differs from the conventional bridge in construction monitoring technology due to its complex structure and prominent spatial effect.To investigate the key technology in construction monitoring,this study took a long-span skewed arch and curved beam bridge as the engineering background and discussed construction process simulation analysis,field monitoring,and parameter identification and adjustment of the bridge.The results show that the plate-shell unit model has higher calculation accuracy and can comprehensively show the stresses in all directions of the bridge compared with the beam element …

Study On Aerodynamic Optimization Of Π-Shaped Cable-Stayed Bridge With Vortex-Induced Vibration In Mountainous Areas, Zeng Min, Liu Hanyun, Mao Na, Chen Baixiang, Han Yan, Li Chunguang

Journal of China & Foreign Highway

Given vortex-induced vibrations of bridges caused by high wind attack angles in mountainous canyons,this study investigated the vortex-induced dynamic characteristics of a Π-shaped steel-concrete composite beam cable-stayed bridge in a mountainous canyon under high wind attack angles based on wind tunnel tests and examined aerodynamic measures for vortex suppression.Firstly,a finite element model of the bridge was established,and the dynamic characteristics of the bridge in both the completed and construction states were analyzed.Subsequently,a 1∶50 scale detailed segment model was designed based on similarity theory to analyze the vortex-induced vibration performance of the original main beam under conventional wind attack angles of …

Wind Tunnel Experiment On Wind-In Duced Vibration Performance Of Arch-Shaped Inclined Steel Bridge Tower In Construction Free-Standing State Using Ae Roelastic Model, Xu Peijun, Deng Fei Yun, Chen Shixuan, Zhang Jiren

Journal of China & Foreign Highway

This paper presented a wind tunnel experimental study on the wind-induced response characteristics of a rectangular-sectioned arch-shaped inclined steel bridge tower during the construction free-standing stage.A 1:50 scaled aeroelastic model was employed to conduct experiments at different wind yaw angles β (0°‒180°).The experimental results indicate:① under the uniform flow field,the tower in its free-standing state does not experience galloping when the bridge ’s wind speed reaches 60 m/s;② under the uniform flow field,the tower exhibits bending vortex-induced vibrations (VIVs ) along the bridge direction or transverse to the bridge direction.However,the amplitudes of the tower top displacements associated with these VIVs …

Numerical Simulation Study On Scour Erosion Of Bridge Pile Foundations In Service, Wang Shang, Mi Jiangchuan, Chen Mingtao, Song Dan, Zhang Qiao, Zhang Yong, Wang Weixiao

Journal of China & Foreign Highway

Bridge pile foundations in servic e are subjected to long-term scour erosion caused by sediment-laden water flow,leading to a gradual expansion of the eroded and worn areas.This in turn results in varying degrees of damage to the pile foundation structure and reduces the durability and safety of the bridge.In order to study the impact of scour erosion on bridge pile foundations,this study took the Hanjiang No.1 Bridge in Ankang City as the research object.The ANSYS FLUENT software was used to conduct three-dimensional numerical simulations of the pile foundation and analyze the distribution characteristics and patterns of scour erosion under different …

Research On Influence Of Shield Synchronous Grouting Parameters On Surface Deformation, Luo Xu, Zhang Zhaofeng, Fu Helin, Cao Guiqian, Zhao Chuanming

Journal of China & Foreign Highway

In order to determine reasonable grouting parameters,control surface settlement,and reduce the risk of excessive surface settlement caused by irrational synchronous grouting parameters,this study studied the shield tunnel project between maglev T 2 station and maglev T 3 station.A numerical simulation method was adopted to study the influence of grouting pressure,grouting volume,and the elastic modulus of slurry on surface deformation.The results show that the tunnel synchronous grouting has a significant effect on surface settlement control.A greater grouting pressure,equivalent grouting layer thickness,and elastic modulus of slurry mean a smaller surface settlement.As the three parameters increase,the variation range of surface settlement decreases and …

Intelligent Vehicle Path Tracking Control Integrating Road Adhesion Constraints, Zhang Zhiguo, Wang Pu, Zhang Xinglong, Wang Yan

Journal of China & Foreign Highway

In the field of fault-tolerant control for intelligent vehicle path tracking,the existing methods based on model predictive control (MPC ) have limitations.They often assume that the vehicle model parameters are fixed and ignore the impact of dynamic changes in model parameters,which are caused by factors such as vehicle load changes and external environmental interference,on the path tracking accuracy.When the steering system fails,the front wheel steering angle commands calculated by MPC cannot be directly executed and need to be converted into yaw moment control.Although the existing sliding mode yaw moment control methods have strong robustness,the chattering problem affects the stability and …

Research On Parametric Method Of Highway Bim Based On Digital Delivery, Li Jinlong, Wang Xinnan

Journal of China & Foreign Highway

By analyzing the application points and the current situation of digital delivery in each stage of highway engineering construction,this study found that the lack of parameter management and definition in the modification and refinement process of building information modeling (BIM ) source files at each stage led to difficulties in the splitting and refinement of BIM at each stage and even the need for reconstruction.To this end,a method for strengthening the overall planning of the whole life cycle was proposed.By clarifying the demand for model parameters according to the application points of each stage,a mechanism for parameter reservation and classification …

Reconstruction Plan Of Small-Spacing Interchange Connection Sections On Expressway : A Case Study Of Xinlong‒Gangkou Interchange On Zhongshan‒Jiangmen Expressway, Jie Qiang, Fu Xinsha

Journal of China & Foreign Highway

The plan design for the small-spacing interchange connection on the expressway directly affects operational efficiency and driving safety.To achieve the conversion of traffic flow between different expressways,this study explored the reconstruction plan of the connection section under the condition that the interchange spacing did not meet the Design Specification for Highway Alignment (JTG D20‒2017 ) and investigated two connection schemes,including auxiliary lane and collector-distributor lane by taking the Xinlong –Gangkou interchange of the Zhongshan‒Jiangmen Expressway reconstruction and expansion project as an example.The results show that the auxiliary lane is recommended in consideration of the long-term service level,speed coordination,operational efficiency,and engineering …

Design Of Champlain Bridge In Canada, Xie Yaning, Zhou Yanfeng, Marwan Nader

Journal of China & Foreign Highway

The Champlain Bridge,an iconic gateway spanning the St.Lawrence River in Montreal,showcases not only the excellence of engineering but also becomes an integral part of the city ’s landscape.With a main span of 240 m,the bridge employs a unique single-pylon harp-shaped double-plane cable-stayed structure.The upper pylon is inspired by a tuning fork in its lateral design,while the upper crossbeam artfully mimics the shape of a bow tie,endowing the bridge with a visual beauty that harmoniously blends elegance and strength.The bridge deck,with a total width of 60 m,was the widest double-plane cable-stayed bridge in the world when it was completed.The typical spans …

Research On Bridge Jacking Decision Based On Carbon Emission Analysis, Zhang Xinmin, Hu Chengze, Gao Hongbo, Yang Yunping, Sun Zhihong, Cao Hongyou

Journal of China & Foreign Highway

To lift the longitudinal section of existing bridges in highway reconstruction and expansion projects due to insufficient under-bridge clearance,this study took the reconstruction of a 32.5 m T-beam bridge in the reconstruction and expansion project of the Guangzhou‒Shenzhen Expressway as the research object.By using a carbon emission factor method,carbon emissions of three reconstruction schemes,including broken-column jacking,conversion of bearing pads into bridge piers,and demolition and reconstruction,were calculated under different lifting heights,and the corresponding construction and installation costs were compared.The results show that when the longitudinal section of the bridge is lifted to a certain height,the economic benefits of the broken-column jacking …

Research On Rc-Uhpc Composite Slab Frame Culvert Technology In Wave-Affected Areas, Qiu Junfeng

Journal of China & Foreign Highway

To address the problems in the construction of offshore bridges and culverts such as the structures susceptible to waves,limited layout,and high cost of soft foundation treatment,this paper proposed a new technical solution for reinforced concrete and ultra-high performance concrete (RC-UHPC ) composite slab frame culverts.With supporting engineering,the ordinary box culvert was selected as a comparison scheme for technical and economic analysis,and the design points and construction procedures of new structures were introduced.Based on the calculation results of the overall bearing force,the bearing performance of the top slab under different load conditions was analyzed,along with an investigation of the secondary internal …

Inverse Analysis Of Thermal Parameters Of Concrete Box Girder Based On De-Bp Neural Network, Yao Yong, Yan Yu, Sun Bo Wen, Wang Yuesong, Jiang Tianyong

Journal of China & Foreign Highway

In view of temperature cracks in concrete box girders easily occurring during construction,an inverse analysis method based on uniform design theory and differential evolution back propagation (DE-BP ) neural network was proposed to accurately obtain the thermal parameters of concrete box girders and ensure the reliability of temperature analysis of concrete box girders.This method established the nonlinear relationship between the temperature peak of characteristic points and the thermal parameters through the DE-BP neural network.By using the uniform design method and the Abaqus finite element numerical model,130 sets of sample data were generated.Based on the ratio of 12∶1 for training samples …

Field Test Research On Optimization Of Smooth Blasting Parameters Based On Drilling Speed, Wang Haitao, Lu Jianghua, Liu Yang, Huang Mingli, Wu Xuan

Journal of China & Foreign Highway

This study aims to address poor adaptability and timeliness in the design of smooth blasting hole parameters in t he past.With the drilling and blasting method-based construction of large cross-section tunnels in Botanggou and Tielugou along the Zunhua‒Qinhuangdao Expressway as the research background and Ⅲ and Ⅳ grade surrounding rocks of porphyritic granite as the research object,statistical regression analysis and theoretical derivation were conducted on the measured data during on-site drilling according to the rock solidity coefficient.Based on this,a simple parameter design method for a smooth blasting layer based on the drilling speed index of an air leg anchor rod …

Distribution Characteristics Of Internal Distress And Maintenance Decision-Making For Asphalt Pavement Based On Three-Dimensional Ground-Penetrating Radar, Li Xiaohua, Song Liang, Ye Wei, Xie Xiaodong, Yang Jiangang, Gao Jie

Journal of China & Foreign Highway

The distribution characteristics of internal distress in pavement structures and the corresponding maintenance decisions are crucial for improving road performance and extending service life.Based on three-dimensional ground-penetrating radar (3D GPR ) technology,this study investigated the internal distress of a 12-kilometer section of both driving and overtaking lanes of an expressway in Hubei Province.High-resolution images of internal pavement distress were obtained,and milling maintenance decisions were optimized by employing these images and a modular decision-making model.Through an efficient and non-destructive technique,the distribution characteristics of internal pavement distress were analyzed,and potential distress types were identified,providing a scientific basis for maintenance decision-making.Data analysis revealed …

Welfare Implication Of Alternative Tax Rates Adjustment Policy In Nigeria: A Dsge Analysis, Umar B. Ibrahim, Isah F. Abubakar

CBN Journal of Applied Statistics (JAS)

This study sets out to determine the desirable policy adjustment in the tax rate for Nigeria that ensures the least welfare cost. A calibrated small open-economy New Keynesian Dynamic Stochastic General Equilibrium (NKDSGE) model of the Nigerian economy is applied to achieve this objective. Within this framework, we examined the impact of an increase in value-added tax (VAT) rate from 7.5 to 15 percent on key macroeconomic variables relative to the impact of an increase in company income tax (CIT) rate from 30 to 35 percent on macroeconomic variables. Furthermore, we examined the welfare costs of the increases in the …

Data Driven Analysis Of Samara Seed Kinematics And Dynamics, Shashwat Sparsh

Master's Theses

Samara Seeds are a class of fruit most famously belonging to the Acer species and are characterized by their single-bladed geometry and their auto-rotation response during descent. This steady-state auto-rotation response is the subject of aerodynamic analysis which aim to quantify the performance. The period prior to the beginning of steady-state auto-rotation is classified as the transition regime and has not been the subject of intense scrutiny.

This thesis employs a data-driven approach to analyzing the kinematic and dynamic response of these seeds during both the transition and auto-rotation stages of flight to quantify the performance with respect to the …

Opening The Black Box With Regal: A Novel Explainable Ai Approach To Uncover Key Predictors In Search And Rescue Success, Brandon Hyunjun Kim

Master's Theses

The outcome of a search and rescue (SAR) operation is influenced by a complex, non-linear interplay among numerous factors, including geographic context, subject-specific characteristics, and environmental conditions. The high dimensionality and intricate dependencies among these variables pose significant challenges to traditional exploratory modeling approaches, limiting their ability to uncover meaningful patterns and relationships associated with mission success. This study introduces Rules Based Explanations for Generated neighborhoods Around Localized cases (REGAL), a novel adaptation of the Local Interpretable Model-agnostic Explanations (LIME) framework to explain deep multimodal neural networks and what key features it assesses to determine search and rescue success. REGAL …

Using Gaussian Process Regression To Learn Thermodynamic Equations Of State With Uncertainty Quantification, Austen T. Lee

Chemical Engineering Undergraduate Honors Theses

This study investigates the use of derivative-informed Gaussian Process (GP) models to estimate thermodynamic behavior across temperature and density by building a Helmholtz-based equation of state. Argon, a stable monatomic gas, was chosen as a case study within the vapor region. The GP model was trained using values of experimentally measurable properties found by taking first and second derivatives of the original potential function. Results show that while the GP model offered uncertainty quantification and informed thermodynamic behavior, it predicted values that deviated from the ground truth depending on the property. The model exhibited high confidence in regions with substantial …