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Pedestrian lane formation with following–overtaking model and measurement of system order
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作者 李碧璐 李政 +1 位作者 周睿 申世飞 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期247-263,共17页
Pedestrian self-organizing movement plays a significant role in evacuation studies and architectural design.Lane formation,a typical self-organizing phenomenon,helps pedestrian system to become more orderly,the majori... Pedestrian self-organizing movement plays a significant role in evacuation studies and architectural design.Lane formation,a typical self-organizing phenomenon,helps pedestrian system to become more orderly,the majority of following behavior model and overtaking behavior model are imprecise and unrealistic compared with pedestrian movement in the real world.In this study,a pedestrian dynamic model considering detailed modelling of the following behavior and overtaking behavior is constructed,and a method of measuring the lane formation and pedestrian system order based on information entropy is proposed.Simulation and analysis demonstrate that the following and avoidance behaviors are important factors of lane formation.A high tendency of following results in good lane formation.Both non-selective following behavior and aggressive overtaking behavior cause the system order to decrease.The most orderly following strategy for a pedestrian is to overtake the former pedestrian whose speed is lower than approximately 70%of his own.The influence of the obstacle layout on pedestrian lane and egress efficiency is also studied with this model.The presence of a small obstacle does not obstruct the walking of pedestrians;in contrast,it may help to improve the egress efficiency by guiding the pedestrian flow and mitigating the reduction of pedestrian system orderliness. 展开更多
关键词 pedestrian movement lane formation information entropy order degree
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Hybrid pedestrian positioning system using wearable inertial sensors and ultrasonic ranging
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作者 Lin Qi Yu Liu +2 位作者 Chuanshun Gao Tao Feng Yue Yu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期327-338,共12页
Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional ... Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional PPS is limited by the cumulative error of inertial sensors,complex motion modes of pedestrians,and the low robustness of the multi-sensor collaboration structure.This paper presents a hybrid pedestrian positioning system using the combination of wearable inertial sensors and ultrasonic ranging(H-PPS).A robust two nodes integration structure is developed to adaptively combine the motion data acquired from the single waist-mounted and foot-mounted node,and enhanced by a novel ellipsoid constraint model.In addition,a deep-learning-based walking speed estimator is proposed by considering all the motion features provided by different nodes,which effectively reduces the cumulative error originating from inertial sensors.Finally,a comprehensive data and model dual-driven model is presented to effectively combine the motion data provided by different sensor nodes and walking speed estimator,and multi-level constraints are extracted to further improve the performance of the overall system.Experimental results indicate that the proposed H-PPS significantly improves the performance of the single PPS and outperforms existing algorithms in accuracy index under complex indoor scenarios. 展开更多
关键词 pedestrian positioning system Wearable inertial sensors Ultrasonic ranging Deep-learning Data and model dual-driven
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IR-YOLO: Real-Time Infrared Vehicle and Pedestrian Detection
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作者 Xiao Luo Hao Zhu Zhenli Zhang 《Computers, Materials & Continua》 SCIE EI 2024年第2期2667-2687,共21页
Road traffic safety can decrease when drivers drive in a low-visibility environment.The application of visual perception technology to detect vehicles and pedestrians in infrared images proves to be an effective means... Road traffic safety can decrease when drivers drive in a low-visibility environment.The application of visual perception technology to detect vehicles and pedestrians in infrared images proves to be an effective means of reducing the risk of accidents.To tackle the challenges posed by the low recognition accuracy and the substan-tial computational burden associated with current infrared pedestrian-vehicle detection methods,an infrared pedestrian-vehicle detection method A proposal is presented,based on an enhanced version of You Only Look Once version 5(YOLOv5).First,A head specifically designed for detecting small targets has been integrated into the model to make full use of shallow feature information to enhance the accuracy in detecting small targets.Second,the Focal Generalized Intersection over Union(GIoU)is employed as an alternative to the original loss function to address issues related to target overlap and category imbalance.Third,the distribution shift convolution optimization feature extraction operator is used to alleviate the computational burden of the model without significantly compromising detection accuracy.The test results of the improved algorithm show that its average accuracy(mAP)reaches 90.1%.Specifically,the Giga Floating Point Operations Per second(GFLOPs)of the improved algorithm is only 9.1.In contrast,the improved algorithms outperformed the other algorithms on similar GFLOPs,such as YOLOv6n(11.9),YOLOv8n(8.7),YOLOv7t(13.2)and YOLOv5s(16.0).The mAPs that are 4.4%,3%,3.5%,and 1.7%greater than those of these algorithms show that the improved algorithm achieves higher accuracy in target detection tasks under similar computational resource overhead.On the other hand,compared with other algorithms such as YOLOv8l(91.1%),YOLOv6l(89.5%),YOLOv7(90.8%),and YOLOv3(90.1%),the improved algorithm needs only 5.5%,2.3%,8.6%,and 2.3%,respectively,of the GFLOPs.The improved algorithm has shown significant advancements in balancing accuracy and computational efficiency,making it promising for practical use in resource-limited scenarios. 展开更多
关键词 Traffic safety infrared image pedestrians and vehicles focal GIoU distributed shift convolution
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Method of improving pedestrian navigation performance based on chest card
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作者 CHENG Hao GAO Shuang +2 位作者 CAI Xiaowen WANG Yuxuan WANG Jie 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期987-998,共12页
With the development of positioning technology,loca-tion services are constantly in demand by people.As a primary location service pedestrian navigation has two main approaches based on radio and inertial navigation.T... With the development of positioning technology,loca-tion services are constantly in demand by people.As a primary location service pedestrian navigation has two main approaches based on radio and inertial navigation.The pedestrian naviga-tion based on radio is subject to environmental occlusion lead-ing to the degradation of positioning accuracy.The pedestrian navigation based on micro-electro-mechanical system inertial measurement unit(MIMU)is less susceptible to environmental interference,but its errors dissipate over time.In this paper,a chest card pedestrian navigation improvement method based on complementary correction is proposed in order to suppress the error divergence of inertial navigation methods.To suppress atti-tude errors,optimal feedback coefficients are established by pedestrian motion characteristics.To extend navigation time and improve positioning accuracy,the step length in subsequent movements is compensated by the first step length.The experi-mental results show that the positioning accuracy of the pro-posed method is improved by more than 47%and 44%com-pared with the pure inertia-based method combined with step compensation and the traditional complementary filtering com-bined method with step compensation.The proposed method can effectively suppress the error dispersion and improve the positioning accuracy. 展开更多
关键词 pedestrian navigation micro-electro-mechanical sy-stem(MEMS) inertial navigation complementary filtering
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Lightweight Cross-Modal Multispectral Pedestrian Detection Based on Spatial Reweighted Attention Mechanism
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作者 Lujuan Deng Ruochong Fu +3 位作者 Zuhe Li Boyi Liu Mengze Xue Yuhao Cui 《Computers, Materials & Continua》 SCIE EI 2024年第3期4071-4089,共19页
Multispectral pedestrian detection technology leverages infrared images to provide reliable information for visible light images, demonstrating significant advantages in low-light conditions and background occlusion s... Multispectral pedestrian detection technology leverages infrared images to provide reliable information for visible light images, demonstrating significant advantages in low-light conditions and background occlusion scenarios. However, while continuously improving cross-modal feature extraction and fusion, ensuring the model’s detection speed is also a challenging issue. We have devised a deep learning network model for cross-modal pedestrian detection based on Resnet50, aiming to focus on more reliable features and enhance the model’s detection efficiency. This model employs a spatial attention mechanism to reweight the input visible light and infrared image data, enhancing the model’s focus on different spatial positions and sharing the weighted feature data across different modalities, thereby reducing the interference of multi-modal features. Subsequently, lightweight modules with depthwise separable convolution are incorporated to reduce the model’s parameter count and computational load through channel-wise and point-wise convolutions. The network model algorithm proposed in this paper was experimentally validated on the publicly available KAIST dataset and compared with other existing methods. The experimental results demonstrate that our approach achieves favorable performance in various complex environments, affirming the effectiveness of the multispectral pedestrian detection technology proposed in this paper. 展开更多
关键词 Multispectral pedestrian detection convolutional neural networks depth separable convolution spatially reweighted attention mechanism
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Measuring Pedestrian Stress Response (MPSR) Using Wearable Technologies
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作者 Ishita Dash Rachael Anne Muscatello +2 位作者 Mark D. Abkowitz Ella R. Mostoller Mike Sewell 《Journal of Transportation Technologies》 2024年第2期224-235,共12页
Walkability is an essential aspect of urban transportation systems. Properly designed walking paths can enhance transportation safety, encourage pedestrian activity, and improve community quality of life. This, in tur... Walkability is an essential aspect of urban transportation systems. Properly designed walking paths can enhance transportation safety, encourage pedestrian activity, and improve community quality of life. This, in turn, can help achieve sustainable development goals in urban areas. This pilot study uses wearable technology data to present a new method for measuring pedestrian stress in urban environments and the results were presented as an interactive geographic information system map to support risk-informed decision-making. The approach involves analyzing data from wearable devices using heart rate variability (RMSSD and slope analysis) to identify high-stress locations. This data-driven approach can help urban planners and safety experts identify and address pedestrian stressors, ultimately creating safer, more walkable cities. The study addresses a significant challenge in pedestrian safety by providing insights into factors and locations that trigger stress in pedestrians. During the pilot study, high-stress pedestrian experiences were identified due to issues like pedestrian-scooter interaction on pedestrian paths, pedestrian behavior around high foot traffic areas, and poor visibility at pedestrian crossings due to inadequate lighting. 展开更多
关键词 Wearable Technology WALKABILITY Built Environment pedestrian Safety
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A Workable Solution for Reducing the Large Number of Vehicle and Pedestrian Accidents Occurring on a Yellow Light
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作者 Pranav Gupta Silki Arora 《Journal of Transportation Technologies》 2024年第1期82-87,共6页
Traffic intersections are incredibly dangerous for drivers and pedestrians. Statistics from both Canada and the U.S. show a high number of fatalities and serious injuries related to crashes at intersections. In Canada... Traffic intersections are incredibly dangerous for drivers and pedestrians. Statistics from both Canada and the U.S. show a high number of fatalities and serious injuries related to crashes at intersections. In Canada, during 2019, the National Collision Database shows that 28% of traffic fatalities and 42% of serious injuries occurred at intersections. Likewise, the U.S. National Highway Traffic Administration (NHTSA) found that about 40% of the estimated 5,811,000 accidents in the U.S. during the year studied were intersection-related crashes. In fact, a major survey by the car insurance industry found that nearly 85% of drivers could not identify the correct action to take when approaching a yellow traffic light at an intersection. One major reason for these accidents is the “yellow light dilemma,” the ambiguous situation where a driver should stop or proceed forward when unexpectedly faced with a yellow light. This situation is even further exacerbated by the tendency of aggressive drivers to inappropriately speed up on the yellow just to get through the traffic light. A survey of Canadian drivers conducted by the Traffic Injury Research Foundation found that 9% of drivers admitted to speeding up to get through a traffic light. Another reason for these accidents is the increased danger of making a left-hand turn on yellow. According to the National Highway Traffic Safety Association (NHTSA), left turns occur in approximately 22.2% of collisions—as opposed to just 1.2% for right turns. Moreover, a study by CNN found left turns are three times as likely to kill pedestrians than right turns. The reason left turns are so much more likely to cause an accident is because they take a driver against traffic and in the path of oncoming cars. Additionally, most of these left turns occur at the driver’s discretion—as opposed to the distressingly brief left-hand arrow at busy intersections. Drive Safe Now proposes a workable solution for reducing the number of accidents occurring during a yellow light at intersections. We believe this fairly simple solution will save lives, prevent injuries, reduce damage to public and private property, and decrease insurance costs. 展开更多
关键词 Traffic Accidents Yellow Light Traffic Light Signals INTERSECTION Crashes Collision Traffic Fatalities Traffic Injuries Vehicles SAFETY Speed Limit Driving pedestrians Bicyclists MOTORCYCLISTS Caution Line Yellow Light Dilemma Left Hand Turn on Yellow Distance Smart Road Technology Signs Signage Autonomous Vehicles AVs Road Safety IoT Internet of Things Infrastructure Accident Reduction Driving Habits Stop Line Red Light Jumping pedestrian Safety Caution Light Stopping at Intersection Safety at Intersections
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An Application of RGBD-Based Skeleton Reconstruction for Pedestrian Detection and Occlusion Handling
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作者 Ziyuan Liu 《Journal of Computer and Communications》 2024年第1期147-161,共15页
This study explores the challenges posed by pedestrian detection and occlusion in AR applications, employing a novel approach that utilizes RGB-D-based skeleton reconstruction to reduce the overhead of classical pedes... This study explores the challenges posed by pedestrian detection and occlusion in AR applications, employing a novel approach that utilizes RGB-D-based skeleton reconstruction to reduce the overhead of classical pedestrian detection algorithms during training. Furthermore, it is dedicated to addressing occlusion issues in pedestrian detection by using Azure Kinect for body tracking and integrating a robust occlusion management algorithm, significantly enhancing detection efficiency. In experiments, an average latency of 204 milliseconds was measured, and the detection accuracy reached an outstanding level of 97%. Additionally, this approach has been successfully applied in creating a simple yet captivating augmented reality game, demonstrating the practical application of the algorithm. 展开更多
关键词 AR pedestrian Detection Occlusion Management RGB-D Azure Kinect UNITY
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Method for pedestrian signal timing at signalized intersections 被引量:3
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作者 王京元 王炜 《Journal of Southeast University(English Edition)》 EI CAS 2006年第4期564-569,共6页
The pedestrian timing at signalized intersections is studied aiming at the problems of the inconsistency of the vehicular and pedestrian timing requirements and the insufficiency of pedestrian clearance. Based on the ... The pedestrian timing at signalized intersections is studied aiming at the problems of the inconsistency of the vehicular and pedestrian timing requirements and the insufficiency of pedestrian clearance. Based on the formulae of WALK and flashing DON'T WALK (FDW) in the highway capacity manual (HCM), the relationship between pedestrian signal indications and vehicular signal indications is discussed using the theory of traffic flow. Then, methods of pedestrian timing for different cases are established, particularly the methods of the pedestrian green adjustment. Ways of pedestrian crossing are analyzed for roadways with different forms and widths of the median island. The sampling values of calculation parameters are studied, and the recommended formulae of pedestrian timing for different conditions are presented. 展开更多
关键词 signalized intersection pedestrian signal timing WALK indication flashing DON'T WALK indication
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Plant Landscape Design for Commercial Pedestrian Streets 被引量:1
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作者 毛燕 王熙 《Journal of Landscape Research》 2010年第9期6-8,28,共4页
In view of the deficiencies in landscaping of commercial pedestrian streets,this study elaborated the functions of plant landscapes,such as improving the street environment,beautifying the street,creating spaces of di... In view of the deficiencies in landscaping of commercial pedestrian streets,this study elaborated the functions of plant landscapes,such as improving the street environment,beautifying the street,creating spaces of diversified uses,and attracting more pedestrians.On the basis of this,plant landscape design principles and techniques for commercial pedestrian streets were put forward,by combining with successful cases,relevant design suggestions were given for particular streets or environments,so as to provide references for the landscaping of commercial pedestrian streets. 展开更多
关键词 COMMERCIAL pedestrian STREET Plant LANDSCAPE ECOLOGICAL BENEFIT Design technique
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Study on the model of pedestrian cross-time in signalized intersection
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作者 徐良杰 《Journal of Southeast University(English Edition)》 EI CAS 2008年第4期513-516,共4页
For studying the law of pedestrian cross-time in the signalized intersection, based on gap theory, a probability chorological discipline model of crossing pedestrians is built based on the observed data. Moreover, the... For studying the law of pedestrian cross-time in the signalized intersection, based on gap theory, a probability chorological discipline model of crossing pedestrians is built based on the observed data. Moreover, the number of pedestrians passing through in a critical gap is estimated under different conditions by three models. Then the models of pedestrian crosswalk average time, the 85th percentile pedestrian cross-time and the 90th percentile pedestrian cross-time are deduced. By quantitative analyses and the exemplification of the models, the main correlative factors acting on pedestrian cross-time are found, including the length of the crosswalk, the probability of the time-headway being less than the critical gap and the number of the turned motor vehicles in the intersection. The results indicate that the estimated errors of the models are less than 5%. 展开更多
关键词 signalized intersection CONFLICT critical gap pedestrian cross-time
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Study on the Landscape Creation of Historical Commercial Pedestrian Streets——With the Five Horses Street in Wenzhou City as a Study Case 被引量:1
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作者 李翔 朱圣潮 刘益曦 《Journal of Landscape Research》 2010年第11期20-23,共4页
With the development of business management model,commercial spaces have required more and more supporting services from the city.However,although commercial pedestrian streets lying on historical blocks have advantag... With the development of business management model,commercial spaces have required more and more supporting services from the city.However,although commercial pedestrian streets lying on historical blocks have advantages in geological culture,they are not able to organically combine with the city environment,landscape creation on such streets have more and more problems.Taking the Five Horses Street in Wenzhou City for an example,this study through field investigation and document consultation proposes the principles and approaches of creating landscapes in historical commercial pedestrian streets,to provide support for the rational utilization of such streets. 展开更多
关键词 HISTORICAL commercial pedestrian STREET LANDSCAPE CREATION Spatial environment
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Virtual Reconstruction of Long Bone Fracture in Car-to-pedestrian Collisions Using Multi-body System and Finite Element Method 被引量:10
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作者 HAN Yong YANG Jikuang MIZUNO Koji 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第6期1045-1055,共11页
Lower limb injures are frequently observed in passenger car traffic accidents.Previous studies of the injuries focus on long bone fractures by using either cadaver component tests or simulations of the long bone kinem... Lower limb injures are frequently observed in passenger car traffic accidents.Previous studies of the injuries focus on long bone fractures by using either cadaver component tests or simulations of the long bone kinematics,which lack in-depth study on the fractures in stress analysis.This paper aims to investigate lower limb impact biomechanics in real-world car to pedestrian accidents and to predict fractures of long bones in term of stress parameter for femur,tibia,and fibula.For the above purposes,a 3D finite element(FE) model of human body lower limb(HBM-LL) is developed based on human anatomy.The model consists of the pelvis,femur,tibia,fibula,patella,foot bones,primary tendons,knee joint capsule,meniscus,and ligaments.The FE model is validated by comparing the results from a lateral impact between simulations and tests with cadaver lower limb specimens.Two real-world accidents are selected from an in-depth accident database with detailed information about the accident scene,car impact speed,damage to the car,and pedestrian injuries.Multi-body system(MBS) models are used to reconstruct the kinematics of the pedestrians in the two accidents and the impact conditions are calculated for initial impact velocity and orientations of the car and pedestrian during the collision.The FE model is used to perform injury reconstructions and predict the fractures by using physical parameters,such as von Mises stress of long bones.The calculated failure level of the long bones is correlated with the injury outcomes observed from the two accident cases.The reconstruction result shows that the HBM-LL FE model has acceptable biofidelity and can be applied to predict the risk of long bone fractures.This study provides an efficient methodology to investigate the long bone fracture suffered from vehicle traffic collisions. 展开更多
关键词 passenger car pedestrian accident lower limb FE model long bone fracture impact biomechanics
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Analysis of conflict factors between pedestrians and right-turning vehicles at signalized intersections 被引量:8
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作者 Chen Yongheng Liu Fanghong +2 位作者 Bai Qiaowen Tao Chuqing Qi Xingzu 《Journal of Southeast University(English Edition)》 EI CAS 2019年第1期118-124,共7页
Due to the fact that there is no protected signal phase for right turns at most signalized intersections, the conflict between pedestrians and right-turning vehicles is one of the most common conflict types for pedest... Due to the fact that there is no protected signal phase for right turns at most signalized intersections, the conflict between pedestrians and right-turning vehicles is one of the most common conflict types for pedestrians. A pedestrian safety analysis of the common right-turn mode at four-phase signalized intersections is presented. Relative risk is used as a measure of the effect of behaviors. The analysis mainly includes five pedestrian factors that affect the conflict process between pedestrians and right-turning vehicles. Pedestrians tend to have a higher risk of being involved in conflicts in the following six situations: crossing with others, running over the crossing, entering the intersection, being near the exit lane, crossing in the middle or at the end of a green light when the right-turn lane is shared, crossing at the beginning of a green light or red period when the right-turn lane is exclusive. It is easier for pedestrians to get priority when crossing the street in the following situations: running over a crossing, entering the intersection, being near the entrance lane, and not using the crosswalk. However, pedestrians are more inclined to yield to right-turning vehicles when pedestrians are crossing in the middle of the green light time. Some measures to alleviate the conflict are put forward according to the conclusion. Video observations also indicate that a clear pedestrian waiting area must be marked for both pedestrian safety and right-turning vehicle efficiency at major flat intersections, particularly when the arms cover the lateral dividing strips. 展开更多
关键词 SAFETY conflicts pedestrian behaviors right-turning vehicles relative risk
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Multi-grid simulation of pedestrian counter flow with topological interaction 被引量:7
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作者 马剑 宋卫国 廖光煊 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第12期586-594,共9页
We investigate the dynamics of pedestrian counter flow by using a multi-grid topological pedestrian counter flow model. In the model, each pedestrian occupies multi- rather than only one grid, and interacts with other... We investigate the dynamics of pedestrian counter flow by using a multi-grid topological pedestrian counter flow model. In the model, each pedestrian occupies multi- rather than only one grid, and interacts with others in the form of topological interaction, which means that a moving pedestrian interacts with a fixed number of those nearest neighbours coming from the opposite direction to determine his/her own moving direction. Thus the discretization of space and time are much finer, the decision making process of the pedestrian is more reliable, which all together makes the moving behaviour and boundary conditions much more realistic. When compared with field observations, it can be found that the modified model is able to reproduce well fitted pedestrian collective behaviour such as dynamical variation of lane formation, clustering of pedestrians in the same direction, etc. The fundamental diagram produced by the model fits also well with field data in thc frce flow region. Further analyses indicate that with the increase of the size of pedestrian counter flow system, it becomes harder for the system to transit into a jamming state, while the increase of interaction range does not change the transition point from free flow to jamming flow in the multi-grid topological counter flow model. It is also found that the asymmetry of the injection rate of pedestrians on the boundaries has direct influence on the process of transition from free flow to jamming flow, i.e., a symmetric injection makes it easier for the system to transit into jamming flow. 展开更多
关键词 pedestrian dynamics topological interaction multi-grid model lane formation
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YOLOv2PD:An Efficient Pedestrian Detection Algorithm Using Improved YOLOv2 Model 被引量:9
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作者 Chintakindi Balaram Murthy Mohammad Farukh Hashmi +1 位作者 Ghulam Muhammad Salman A.AlQahtani 《Computers, Materials & Continua》 SCIE EI 2021年第12期3015-3031,共17页
Real-time pedestrian detection is an important task for unmanned driving systems and video surveillance.The existing pedestrian detection methods often work at low speed and also fail to detect smaller and densely dis... Real-time pedestrian detection is an important task for unmanned driving systems and video surveillance.The existing pedestrian detection methods often work at low speed and also fail to detect smaller and densely distributed pedestrians by losing some of their detection accuracy in such cases.Therefore,the proposed algorithm YOLOv2(“YOU ONLY LOOK ONCE Version 2”)-based pedestrian detection(referred to as YOLOv2PD)would be more suitable for detecting smaller and densely distributed pedestrians in real-time complex road scenes.The proposed YOLOv2PD algorithm adopts a Multi-layer Feature Fusion(MLFF)strategy,which helps to improve the model’s feature extraction ability.In addition,one repeated convolution layer is removed from the final layer,which in turn reduces the computational complexity without losing any detection accuracy.The proposed algorithm applies the K-means clustering method on the Pascal Voc-2007+2012 pedestrian dataset before training to find the optimal anchor boxes.Both the proposed network structure and the loss function are improved to make the model more accurate and faster while detecting smaller pedestrians.Experimental results show that,at 544×544 image resolution,the proposed model achieves 80.7%average precision(AP),which is 2.1%higher than the YOLOv2 Model on the Pascal Voc-2007+2012 pedestrian dataset.Besides,based on the experimental results,the proposed model YOLOv2PD achieves a good trade-off balance between detection accuracy and real-time speed when evaluated on INRIA and Caltech test pedestrian datasets and achieves state-of-the-art detection results. 展开更多
关键词 Computer vision K-means clustering multi-layer feature fusion strategy pedestrian detection YOLOv2PD
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Nonfatal Child Pedestrian Injury in Two Urban Cities of Guangdong Province,China:Results from a Cross-sectional Survey 被引量:4
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作者 MA WenJun NIE ShaoPing +3 位作者 XU HaoFeng XU YanJun XIE HuiYan ZHANG YuRun 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2011年第4期335-342,共8页
Objective To describe the epidemiological characteristics of nonfatal child pedestrian injuries and provide information to help understand an important public-health problem.Methods This was a school-based,cross-secti... Objective To describe the epidemiological characteristics of nonfatal child pedestrian injuries and provide information to help understand an important public-health problem.Methods This was a school-based,cross-sectional questionnaire survey.The sample (42 750 children) was obtained from two urban cities of Guangdong Province,China,using multi-stage randomized sampling.Information was collected by the respondents self-reporting in the classroom.Results The incidence rate of nonfatal child pedestrian injuries in the cities was 2.0%.Boys had a higher incidence rate (2.6%) than girls (1.4%).Compared to other children,those aged 10 years are at the highest risk.The primary places of occurrence were sidewalks,residential roads,and crosswalks.High-risk behavior of the children immediately prior to injury included mid-block crossings,playing on roads,and crossing on red lights.The major vehicles that caused pedestrian injuries were bicycles,car or vans,and motorcycles.Bruises,fractures,and injuries to the internal organs were the top three types of injuries.Almost 40% of victims were hospitalized,and nearly 30% of the victims suffered long-term disabilities.Conclusion This study shows that nonfatal child pedestrian injuries are a very serious public-health problem in the urban cities of Guangdong.Based on the epidemiological characteristics,prevention strategies and further research should be carried out to reduce the occurrence of injuries. 展开更多
关键词 CHILDREN pedestrian INJURY Cross-sectional study
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Improved pedestrian detection with peer AdaBoost cascade 被引量:4
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作者 FU Hong-pu ZOU Bei-ji +3 位作者 ZHU Cheng-zhang DAI Yu-lan JIANG Ling-zi CHANG Zhe 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第8期2269-2279,共11页
Focusing on data imbalance and intraclass variation,an improved pedestrian detection with a cascade of complex peer AdaBoost classifiers is proposed.The series of the AdaBoost classifiers are learned greedily,along wi... Focusing on data imbalance and intraclass variation,an improved pedestrian detection with a cascade of complex peer AdaBoost classifiers is proposed.The series of the AdaBoost classifiers are learned greedily,along with negative example mining.The complexity of classifiers in the cascade is not limited,so more negative examples are used for training.Furthermore,the cascade becomes an ensemble of strong peer classifiers,which treats intraclass variation.To locally train the AdaBoost classifiers with a high detection rate,a refining strategy is used to discard the hardest negative training examples rather than decreasing their thresholds.Using the aggregate channel feature(ACF),the method achieves miss rates of 35%and 14%on the Caltech pedestrian benchmark and Inria pedestrian dataset,respectively,which are lower than that of increasingly complex AdaBoost classifiers,i.e.,44%and 17%,respectively.Using deep features extracted by the region proposal network(RPN),the method achieves a miss rate of 10.06%on the Caltech pedestrian benchmark,which is also lower than 10.53%from the increasingly complex cascade.This study shows that the proposed method can use more negative examples to train the pedestrian detector.It outperforms the existing cascade of increasingly complex classifiers. 展开更多
关键词 peer classifier hard negative refining pedestrian detection CASCADE
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Simulation of pedestrian evacuation based on an improved dynamic parameter model 被引量:4
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作者 朱诺 贾斌 +1 位作者 邵春福 岳昊 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第5期66-75,共10页
An improved dynamic parameter model is presented based on cellular automata.The dynamic parameters,including direction parameter,empty parameter,and cognition parameter,are formulated to simplify tactically the proces... An improved dynamic parameter model is presented based on cellular automata.The dynamic parameters,including direction parameter,empty parameter,and cognition parameter,are formulated to simplify tactically the process of making decisions for pedestrians.The improved model reflects the judgement of pedestrians on surrounding conditions and the action of choosing or decision.According to the two-dimensional cellular automaton Moore neighborhood we establish the pedestrian moving rule,and carry out corresponding simulations of pedestrian evacuation.The improved model considers the impact of pedestrian density near exits on the evacuation process.Simulated and experimental results demonstrate that the improvement makes sense due to the fact that except for the spatial distance to exits,people also choose an exit according to the pedestrian density around exits.The impact factors 伪,尾,and 纬 are introduced to describe transition payoff,and their optimal values are determined through simulation.Moreover,the effects of pedestrian distribution,pedestrian density,and the width of exits on the evacuation time are discussed.The optimal exit layout,i.e.,the optimal position and width,is offered.The comparison between the simulated results obtained with the improved model and that from a previous model and experiments indicates that the improved model can reproduce experimental results well.Thus,it has great significance for further study,and important instructional meaning for pedestrian evacuation so as to reduce the number of casualties. 展开更多
关键词 cellular automata pedestrian evacuation dynamic parameter evacuation time
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Exit selection strategy in pedestrian evacuation simulation with multi-exits 被引量:4
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作者 岳昊 张滨雅 +1 位作者 邵春福 邢燕 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第5期195-207,共13页
A mixed strategy of the exit selection in a pedestrian evacuation simulation with multi-exits is constructed by fusing the distance-based and time-based strategies through a cognitive coefficient, in order to reduce t... A mixed strategy of the exit selection in a pedestrian evacuation simulation with multi-exits is constructed by fusing the distance-based and time-based strategies through a cognitive coefficient, in order to reduce the evacuation imbalance caused by the asymmetry of exits or pedestrian layout, to find a critical density to distinguish whether the strategy of exit selection takes effect or not, and to analyze the exit selection results with different cognitive coefficients. The strategy of exit selection is embedded in the computation of the shortest estimated distance in a dynamic parameter model, in which the concept of a jam area layer and the procedure of step-by-step expending are introduced. Simulation results indicate the characteristics of evacuation time gradually varying against cognitive coefficient and the effectiveness of reducing evacuation imbalance caused by the asymmetry of pedestrian or exit layout. It is found that there is a critical density to distinguish whether a pedestrian jam occurs in the evacuation and whether an exit selection strategy is in effect. It is also shown that the strategy of exit selection has no effect on the evacuation process in the no-effect phase with a low density, and that evacuation time and exit selection are dependent on the cognitive coefficient and pedestrian initial density in the in-effect phase with a high density. 展开更多
关键词 pedestrian evacuation exit selection strategy critical density dynamic parameters
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