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Articles 2221 - 2250 of 40872

Full-Text Articles in Engineering

Research On Pavement Crack Segmentation Based On Swin-U, Wang Hua, Wang Liangcai, Xiong Feng, Hu Jing Jun 2025

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 …

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Long-Term Water P Ermeability Performance Of Asphalt Mixtures Under Wide-Scope Void Ratio, Chen Sanxi, Guan Hongxin, Yao Ming, Mo Zhiwei, Jiang Wangheng Jun 2025

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 …

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Research On Key Construction Monitoring Technology Of Long-Span Skewed Arch And Curved Beam Bridge, Xu Yufeng, Zhang Zhantao, Xie Yunfei, Li Zihui Jun 2025

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 …

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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 Jun 2025

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 …

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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 Jun 2025

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 …

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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 Jun 2025

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 …

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Research On Influence Of Shield Synchronous Grouting Parameters On Surface Deformation, Luo Xu, Zhang Zhaofeng, Fu Helin, Cao Guiqian, Zhao Chuanming Jun 2025

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 …

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Intelligent Vehicle Path Tracking Control Integrating Road Adhesion Constraints, Zhang Zhiguo, Wang Pu, Zhang Xinglong, Wang Yan Jun 2025

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 …

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Research On Parametric Method Of Highway Bim Based On Digital Delivery, Li Jinlong, Wang Xinnan Jun 2025

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 …

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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 Jun 2025

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 …

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Design Of Champlain Bridge In Canada, Xie Yaning, Zhou Yanfeng, Marwan Nader Jun 2025

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 …

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Research On Bridge Jacking Decision Based On Carbon Emission Analysis, Zhang Xinmin, Hu Chengze, Gao Hongbo, Yang Yunping, Sun Zhihong, Cao Hongyou Jun 2025

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 …

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Research On Rc-Uhpc Composite Slab Frame Culvert Technology In Wave-Affected Areas, Qiu Junfeng Jun 2025

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 …

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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 Jun 2025

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 …

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Field Test Research On Optimization Of Smooth Blasting Parameters Based On Drilling Speed, Wang Haitao, Lu Jianghua, Liu Yang, Huang Mingli, Wu Xuan Jun 2025

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 …

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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 Jun 2025

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 …

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Context-Switch Attacks: Understanding And Mitigating The Threat To Llm Applications, Sydney Holder, Bivin Sadler Jun 2025

Context-Switch Attacks: Understanding And Mitigating The Threat To Llm Applications, Sydney Holder, Bivin Sadler

SMU Data Science Review

Large Language Models (LLMs) are transforming conversational AI, yet their dependence on prompt-supplied context exposes them to context-switch attacks that covertly steer dialogue toward sensitive or malicious ends. A 70 one-sided conversation transcript evaluation set was constructed spanning various fraudulent scenarios. Each transcript embeds adversarial patterns drawn while preserving natural conversational flow. We introduce a hybrid defense that pairs a BERT-based semantic-drift detector (cosine-similarity threshold = 0.70) with a curated keyword and hack-phrase scanner to counter these threats. In aggregate, the system delivered 100 % recall, intercepting every simulated phishing or data-harvesting attempt. The keyword layer achieved perfect precision, generating …

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Simulation Study On Optimizing Microgrid Scheduling With Electric Vehicle Participation Under V2g Mode, Zhongan Yu, Hongliang Xiao, Qiangwei Xia, Jiawei Liu Jun 2025

Simulation Study On Optimizing Microgrid Scheduling With Electric Vehicle Participation Under V2g Mode, Zhongan Yu, Hongliang Xiao, Qiangwei Xia, Jiawei Liu

Journal of System Simulation

Abstract: To address the negative impact of source-load uncertainty on the stable operation of the grid, a two-stage optimization scheduling strategy for the microgrid participation of electric vehicles based on the vehicle-to-grid (V2G) mode is proposed. In the first stage, the charging and discharging costs of electric vehicles as well as the load fluctuation target are determined taking into account the battery losses. Through a zero-sum game, we objectively weigh the interests of both vehicle owners and the microgrid, utilizing the mobile energy storage characteristics of electric vehicles to optimize the load curve and integrate renewable energy; in the second …

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Aerial Target Detection Algorithm Fused With Multi-Scale Features, Lu Yang, Junying Pei Jun 2025

Aerial Target Detection Algorithm Fused With Multi-Scale Features, Lu Yang, Junying Pei

Journal of System Simulation

Abstract: In order to solve the problem that UAV aerial images have a large number of small target samples but little extractable feature information, which is not conducive to improving the accuracy of aerial target detection, an improved small target detection algorithm for aerial photography based on YOLOv8s is proposed. The algorithm applies deformable convolution to the feature extraction module of the backbone network to adaptively capture the details of the target at different locations and scales. The feature information at different scales of the backbone network is extracted and enhanced by the feature collection module in the multilevel information …

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Development Of A Near Terahertz Backward Wave Oscillator Using Standard Waveguide, Alexander Glick Jun 2025

Development Of A Near Terahertz Backward Wave Oscillator Using Standard Waveguide, Alexander Glick

Electrical and Computer Engineering ETDs

There is a demand for terahertz (THz) frequency radiation sources. Applications include, but are not limited to, imaging for medical and security purposes, biochemical and organic spectroscopy, and velocimetry. Historically, there was a limited supply of THz devices due to technological limitations. In recent years much progress has been made to reduce this “gap” in supply and demand for THz sources. This work proposes a vacuum electronic device that produces high power, extremely high frequency radiation in the G-band, by utilizing a backward wave oscillator (BWO) based on WR3 standard waveguide. This device is compact, fundamentally simple, and has great …

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Finite-Time Robust Anti-Disturbance Control For Steer-By-Wire System, Jingyi Zhang, Xin Chen, Jingang Ding, Jianguo Luo, Shuo Feng Jun 2025

Finite-Time Robust Anti-Disturbance Control For Steer-By-Wire System, Jingyi Zhang, Xin Chen, Jingang Ding, Jianguo Luo, Shuo Feng

Journal of System Simulation

Abstract: To eliminate the influence of parameter perturbations and external disturbances on the wheel angle tracking control performance of steer-by-wire (SbW) system, a fractional-order integral terminal sliding mode control scheme based on a finite-time disturbance observer is proposed. A sliding modebased second order finite-time disturbance observer (FDO) is designed to precisely estimate the total disturbance of the SbW system, and the estimated total disturbance is compensated into the system control input to reduce the wheel angle tracking error. A fractional-order fast integral terminal sliding mode control (FOFITSMC) scheme is designed to ensure fast convergence of the wheel angle tracking error …

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Research On Obstacle Avoidance Of Substation Robot Based On Spatiotemporal Networks, Chong Cheng, Lixia Wang, Songtao Duan, Xiaoguang Xiong, Xianjun Ge Jun 2025

Research On Obstacle Avoidance Of Substation Robot Based On Spatiotemporal Networks, Chong Cheng, Lixia Wang, Songtao Duan, Xiaoguang Xiong, Xianjun Ge

Journal of System Simulation

Abstract: In order to improve the visual obstacle avoidance ability of substation robots in complex environments, a robot visual obstacle avoidance method based on spatiotemporal networks is proposed. The method utilizes traditional image processing techniques to enhance road information and designs a lightweight deep convolutional neural network structure to extract road features from a spatial domain perspective; based on the spatial characteristics of the road, a long short-term memory network is introduced to mine the changes in the road from a temporal perspective, and a classification regression prediction structure is used to predict the robot's obstacle avoidance direction and angle; …

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Operation System For Simulation Roadheader Based On Visual Motion Capture, Yongling Li, Lingzhi Liu, Baishun Zhou, Jingfa Lei, Miao Zhang, Ruhai Zhao Jun 2025

Operation System For Simulation Roadheader Based On Visual Motion Capture, Yongling Li, Lingzhi Liu, Baishun Zhou, Jingfa Lei, Miao Zhang, Ruhai Zhao

Journal of System Simulation

Abstract: To enhance the natural human-machine interaction in simulation roadheader environment, a vision-based simulation roadheader operation system is proposed. The visual motion capture unit is based on the MediaPipe framework, which captures hand gestures through cameras and creates a correspondence between the physical world and virtual space. An improved Kalman filter algorithm is proposed by setting a weighted centroid to address the issue of unreasonable jumps in hand keypoint data during large-scale movements. The operator's gestures are discerned and the corresponding commands are conveyed. The results show that the improved method has significant advantages over the control group in terms …

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Research On Behavior Control Techniques For Autonomous Vehicles Based On Parallel Behavior Tree Architecture, Jianchao Yuan, Shuo Yang, Qi Zhang, Ge Li Jun 2025

Research On Behavior Control Techniques For Autonomous Vehicles Based On Parallel Behavior Tree Architecture, Jianchao Yuan, Shuo Yang, Qi Zhang, Ge Li

Journal of System Simulation

Abstract: Aiming at the problem of high collision rate and low efficiency of traditional serial behavior tree in autonomous vehicle control, a solution based on improved parallel behavior tree architecture is discussed to achieve safe behavior control. A safety behavior control strategy under dynamic road conditions is proposed, and behavior models for observation, decision-making, and movement are constructed, as well as their temporal constraint relationships; an improved parallel behavior tree control architecture is proposed, which achieves parallel execution and real-time interaction of behaviors through parallel control nodes, improving the real-time performance of decision control. The results show that compared with …

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Simulation Study On Adaptive Signal Control Of Deformed Intersection Based On Lstm-Gnn, Kun Chen, Liang Chen, Jiming Xie, Fengbo Liu, Taixiong Chen, Lukuan Wei Jun 2025

Simulation Study On Adaptive Signal Control Of Deformed Intersection Based On Lstm-Gnn, Kun Chen, Liang Chen, Jiming Xie, Fengbo Liu, Taixiong Chen, Lukuan Wei

Journal of System Simulation

Abstract: Aiming at the traffic congestion at deformed intersections, an improved adaptive traffic signal control scheme based on deep learning is designed, the scheme integrates the adaptive signal control of LSTM and GNN at deformed intersections. LSTM is used to capture the dependence between time series traffic data, while GNN is used to construct a spatial interaction model between lanes. By integrating the information of time and space dimensions, the model can dynamically adjust the phase duration of signal lights according to real-time traffic conditions. The results indicate that the LSTM-GNN adaptive control scheme improves overall traffic throughput efficiency by …

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Modeling And Simulation Of Dual-Podded-Propulsion Ship Motions, Bing Han, Yunhe Lin, Yuhang Chen, Zhouhua Peng Jun 2025

Modeling And Simulation Of Dual-Podded-Propulsion Ship Motions, Bing Han, Yunhe Lin, Yuhang Chen, Zhouhua Peng

Journal of System Simulation

Abstract: Aiming at the autonomous navigation control requirements of the Dalian Maritime University's dual-purpose intelligent research and training ship "Xin Hong Zhuan," the design of the motion model for this dual-podded-propulsion ship is carried out. Utilizing an MMG model structure, it calculates the hull's hydrodynamic viscous forces, single/dual-propeller thrust, and hydrodynamic forces acting on the podded propulsion units. Based on data from sea trials and open-water propeller tests, straight-navigation resistance is derived via data fitting, while a method using simulated turning circle tests and PSO algorithms is proposed to determine some hydrodynamic coefficients, refining existing empirical formulas. The model's maneuvering …

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Research On Scenario-Driven Virtual Simulation Test Method For Autonomous Escort Function Of Habor Tugs, Shijie Li, Jialin Li, Jialun Liu, Chengqi Xu, Zhilin Dong Jun 2025

Research On Scenario-Driven Virtual Simulation Test Method For Autonomous Escort Function Of Habor Tugs, Shijie Li, Jialin Li, Jialun Liu, Chengqi Xu, Zhilin Dong

Journal of System Simulation

Abstract: In order to comprehensively construct the test scenarios and verify the reliability of the tugboat autonomous companionway function, a scenario-driven virtual simulation test method for the tugboat autonomous companionway function is proposed. Based on the relative heading, relative speed and relative position of the target ship and the tugboat, the test cases of the tugboat autonomous companionway scenario are generated, and the complexity of the test cases is evaluated by using the fifthorder Bessel curve. The autonomous companion navigation function of the tug is verified through simulation experiments on the complex typical test scenarios without and with obstacles. The …

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Dynamic Path Planning For Robotic Arms Based On An Improved Ppo Algorithm, Yuhang Wan, Zilu Zhu, Chunfu Zhong, Yongkui Liu, Tingyu Lin, Lin Zhang Jun 2025

Dynamic Path Planning For Robotic Arms Based On An Improved Ppo Algorithm, Yuhang Wan, Zilu Zhu, Chunfu Zhong, Yongkui Liu, Tingyu Lin, Lin Zhang

Journal of System Simulation

Abstract: Aiming at the increased environmental uncertainties and more difficult modeling for robotic arm path planning in unstructured environments, an approach to dynamic path planning of robotic arms based on an improved PPO algorithm is proposed. In order to solve the problem that the input length of the state space is not fixed due to the change of number of obstacles in dynamic environment, an environmental state input processing method based on the LSTM network is proposed, and the network structure of PPO algorithm is also improved; a reward function is designed based on the artificial potential field method, and …

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Self-Supervised Defect Detection Via Discriminative Enhancement-Based Distillation Learning, Zhiyuan Feng, Ying Chen Jun 2025

Self-Supervised Defect Detection Via Discriminative Enhancement-Based Distillation Learning, Zhiyuan Feng, Ying Chen

Journal of System Simulation

Abstract: To address the issues of scarce and unknown types of abnormal defect data and the lack of diversity in anomaly representation in conventional knowledge distillation defect detection methods, a self-supervised distillation learning method based on discriminative enhancement is proposed. An attention-based multi-scale feature fusion module is proposed, which enhances the capability of anomaly representation by amplifying the multi-scale feature differences between the student network and the teacher network. A discriminative network composed of a feature reweighting module and a decoder is designed to generate more accurate anomaly score maps by further emphasizing the anomaly features in the teacher network, …

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Research On Robot Dynamic Obstacle Avoidance Method Based On Improved A* And Dynamic Window Algorithm, Yan Zhang, Binghua Li, Tao Huo, Rong Liu Jun 2025

Research On Robot Dynamic Obstacle Avoidance Method Based On Improved A* And Dynamic Window Algorithm, Yan Zhang, Binghua Li, Tao Huo, Rong Liu

Journal of System Simulation

Abstract: Aiming at the problems that the traditional A* algorithm has too many extension nodes and path turning points, and can't deal with dynamic obstacles in complex environment, a robot obstacle avoidance method combining improved A* algorithm and DWA algorithm is proposed. The A* algorithm improves the neighborhood expansion method and effectively avoids the problem of redundant nodes in the classical four-neighborhood expansion and the path through the obstacle in the eight-neighborhood expansion. A quadrant selection method is proposed, which can effectively reduce the number of extended nodes in the path search process. The redundant point elimination strategy is proposed …

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