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Helmet-YOLO:一种更高精度的道路安全头盔检测算法 被引量:3
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作者 周顺勇 彭梓洋 +3 位作者 张航领 胡琴 陆欢 张宗良 《计算机工程与应用》 北大核心 2025年第2期135-144,共10页
针对现有的道路安全头盔检测算法受背景环境影响较大,面对遮挡以及目标与环境相似等检测场景检测精度不高的问题,从特征融合和损失计算的角度,开发了一种新的Helmet-YOLO架构。利用渐进式特征金字塔网络结构降低多尺度特征融合过程中存... 针对现有的道路安全头盔检测算法受背景环境影响较大,面对遮挡以及目标与环境相似等检测场景检测精度不高的问题,从特征融合和损失计算的角度,开发了一种新的Helmet-YOLO架构。利用渐进式特征金字塔网络结构降低多尺度特征融合过程中存在的巨大语义差距,提升算法在复杂场景下的检测能力。同时,提出的PCAHead检测头和HelmetIoU边界框损失函数优化了模型理解和处理数据的能力,提高了模型损失计算的效率和精度,加速了模型的收敛。实验结果表明,Helmet-YOLOn算法和Helmet-YOLOs算法的mAP@50分别提升了3.7和2.9个百分点,优于实验中的所有同尺度模型,另外Helmet-YOLO的大尺度模型在延迟和精度上也优于多数实验模型。实验证明Helmet-YOLO算法具有更高的精度和鲁棒性,更适合复杂场景的道路安全头盔检测。 展开更多
关键词 头盔检测 helmet-YOLO 渐进式特征金字塔网络 PCAHead检测头 helmetIoU
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An Improved Lightweight Safety Helmet Detection Algorithm for YOLOv8
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作者 Lieping Zhang Hao Ma +2 位作者 Jiancheng Huang Cui Zhang Xiaolin Gao 《Computers, Materials & Continua》 2025年第5期2245-2265,共21页
Detecting individuals wearing safety helmets in complex environments faces several challenges.These factors include limited detection accuracy and frequent missed or false detections.Additionally,existing algorithms o... Detecting individuals wearing safety helmets in complex environments faces several challenges.These factors include limited detection accuracy and frequent missed or false detections.Additionally,existing algorithms often have excessive parameter counts,complex network structures,and high computational demands.These challenges make it difficult to deploy such models efficiently on resource-constrained devices like embedded systems.Aiming at this problem,this research proposes an optimized and lightweight solution called FGP-YOLOv8,an improved version of YOLOv8n.The YOLOv8 backbone network is replaced with the FasterNet model to reduce parameters and computational demands while local convolution layers are added.This modification minimizes computational costs with only a minor impact on accuracy.A new GSTA(GSConv-Triplet Attention)module is introduced to enhance feature fusion and reduce computational complexity.This is achieved using attention weights generated from dimensional interactions within the feature map.Additionally,the ParNet-C2f module replaces the original C2f(CSP Bottleneck with 2 Convolutions)module,improving feature extraction for safety helmets of various shapes and sizes.The CIoU(Complete-IoU)is replaced with the WIoU(Wise-IoU)to boost performance further,enhancing detection accuracy and generalization capabilities.Experimental results validate the improvements.The proposedmodel reduces the parameter count by 19.9% and the computational load by 18.5%.At the same time,mAP(mean average precision)increases by 2.3%,and precision improves by 1.2%.These results demonstrate the model’s robust performance in detecting safety helmets across diverse environments. 展开更多
关键词 YOLO safety helmet detection complex environments LIGHTWEIGHT WIoU loss function
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Improved YOLOv8n Model for Detecting Helmets and License Plates on Electric Bicycles 被引量:3
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作者 Qunyue Mu Qiancheng Yu +2 位作者 Chengchen Zhou Lei Liu Xulong Yu 《Computers, Materials & Continua》 SCIE EI 2024年第7期449-466,共18页
Wearing helmetswhile riding electric bicycles can significantly reduce head injuries resulting fromtraffic accidents.To effectively monitor compliance,the utilization of target detection algorithms through traffic cam... Wearing helmetswhile riding electric bicycles can significantly reduce head injuries resulting fromtraffic accidents.To effectively monitor compliance,the utilization of target detection algorithms through traffic cameras plays a vital role in identifying helmet usage by electric bicycle riders and recognizing license plates on electric bicycles.However,manual enforcement by traffic police is time-consuming and labor-intensive.Traditional methods face challenges in accurately identifying small targets such as helmets and license plates using deep learning techniques.This paper proposes an enhanced model for detecting helmets and license plates on electric bicycles,addressing these challenges.The proposedmodel improves uponYOLOv8n by deepening the network structure,incorporating weighted connections,and introducing lightweight convolutional modules.These modifications aim to enhance the precision of small target recognition while reducing the model’s parameters,making it suitable for deployment on low-performance devices in real traffic scenarios.Experimental results demonstrate that the model achieves an mAP@0.5 of 91.8%,showing an 11.5%improvement over the baselinemodel,with a 16.2%reduction in parameters.Additionally,themodel achieves a frames per second(FPS)rate of 58,meeting the accuracy and speed requirements for detection in actual traffic scenarios. 展开更多
关键词 YOLOv8 object detection electric bicycle helmet detection electric bicycle license plate detection
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Analyzing the contribution of helmet components to underwash effect under blast load
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作者 Jiarui Zhang Zhibo Du +4 位作者 Xinghao Wang Yue Kang Tian Ma Zhuo Zhuang Zhanli Liu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2024年第11期1-12,共12页
Helmets exacerbate head injuries to some degree under blast load,which has been recently researched and referred to as the underwash effect.Various studies indicate that the underwash effect is attributed to either wa... Helmets exacerbate head injuries to some degree under blast load,which has been recently researched and referred to as the underwash effect.Various studies indicate that the underwash effect is attributed to either wave interaction or wave-structure interaction.Despite ongoing investigations,there is no consensus on the explanations and verification of proposed mechanisms.This study conducts experiments and numerical simulations to investigate the underwash effect,resulting from the interaction among blast load,helmets,and head models.The analysis of overpressure in experiments and simulations,with the developed simplified models that ignore unimportant geometric details,reveals that the underwash effect arises from the combined action of wave interaction and wave-structure interaction.Initially reflected in front of the head,the blast load converges at the rear after diffraction,forming a high-pressure zone.Decoupling the helmet components demonstrates that the pads alleviate rear overpressure through array hindrance of the load,resulting in a potential reduction of up to 36%in the rear overpressure peak.The helmet shell exacerbates the rear overpressure peak through geometric restriction of the load after diffraction,leading to a remarkable 388%increase in rear overpressure.The prevailing impact of the geometric restriction imposed by the shell of the helmet leads to a significant 57%increase in overpressure when employing a complete helmet. 展开更多
关键词 Blast load helmet Underwash effect Geometric restriction Array hindrance
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HWD-YOLO:A New Vision-Based Helmet Wearing Detection Method
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作者 Licheng Sun Heping Li Liang Wang 《Computers, Materials & Continua》 SCIE EI 2024年第9期4543-4560,共18页
It is crucial to ensure workers wear safety helmets when working at a workplace with a high risk of safety accidents,such as construction sites and mine tunnels.Although existing methods can achieve helmet detection i... It is crucial to ensure workers wear safety helmets when working at a workplace with a high risk of safety accidents,such as construction sites and mine tunnels.Although existing methods can achieve helmet detection in images,their accuracy and speed still need improvements since complex,cluttered,and large-scale scenes of real workplaces cause server occlusion,illumination change,scale variation,and perspective distortion.So,a new safety helmet-wearing detection method based on deep learning is proposed.Firstly,a new multi-scale contextual aggregation module is proposed to aggregate multi-scale feature information globally and highlight the details of concerned objects in the backbone part of the deep neural network.Secondly,a new detection block combining the dilate convolution and attention mechanism is proposed and introduced into the prediction part.This block can effectively extract deep featureswhile retaining information on fine-grained details,such as edges and small objects.Moreover,some newly emerged modules are incorporated into the proposed network to improve safety helmetwearing detection performance further.Extensive experiments on open dataset validate the proposed method.It reaches better performance on helmet-wearing detection and even outperforms the state-of-the-art method.To be more specific,the mAP increases by 3.4%,and the speed increases from17 to 33 fps in comparison with the baseline,You Only Look Once(YOLO)version 5X,and themean average precision increases by 1.0%and the speed increases by 7 fps in comparison with the YOLO version 7.The generalization ability and portability experiment results show that the proposed improvements could serve as a springboard for deep neural network design to improve object detection performance in complex scenarios. 展开更多
关键词 Object detection deep learning safety helmet wearing detection feature extraction attention mechanism
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Knowledge, Attitude, and Practice of Using Helmets in Children amongst Parents to Prevent Head Injuries: A Cross-Sectional Study in Riyadh, Saudi Arabia
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作者 Turki Salah Aldeen Bukhari Abdullah Yahya Aldhban +4 位作者 Anas Abdulrahman Alqasem Dona Jamal Al Hatlani Hareth Aldosaimani Hamad A. Al Madi Khalid Alqahtani 《Open Journal of Pediatrics》 2024年第2期255-265,共11页
Objectives: The primary objective was to characterize the range of Knowledge, Attitude, and Practice (KAP) of Helmet use in children amongst parents to prevent head injuries and death. Methods: This is a cross-section... Objectives: The primary objective was to characterize the range of Knowledge, Attitude, and Practice (KAP) of Helmet use in children amongst parents to prevent head injuries and death. Methods: This is a cross-sectional study, done by online survey using a snowball sampling technique, the number of included responses were 386 parents (Male and female) living in Riyadh Aged 21 - 60 years old or above. Results: The study showed that there is a difference in Parents’ belief in the importance of helmet use while riding a Bicycle vs Motorcycle/Quad bike and that was affected by parents’ education level, almost all the people who answered the survey (76.7%) agree that it is important for their children to wear a helmet when riding both a Bicycle and a Motorcycle or Quadbike with a cumulative percentage of (93.8%). And almost all agreed on multiple approaches to help increase helmet use be it by forcing rental shops to give out helmets, forcing sellers to recommend the use of helmets, increasing awareness campaigns, and imposing fines for not wearing helmets. Conclusions: This study is the first to explore Family helmet use while riding Bicycles and Motorcycles/Quad bikes. Although Parent’s belief in the importance of helmet use for their children was high, it is clear that the level of practice is low. With that the risk of head injuries might be high, our findings suggest that safety interventions for increasing pediatric helmet use are needed to increase helmet use and reduce the risk of head injury and hospitalization. 展开更多
关键词 Head Trauma Head Injury helmet Bicycle Motorcycle Quad Bike KAP Knowledge ATTITUDE PRACTICE
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Modelling ballistic impact on military helmets:The relevance of projectile plasticity 被引量:6
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作者 A.Caçoilo R.Mourao +3 位作者 F.Teixeira-Dias A.Azevedo F.Coghe R.A.F.Valente 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第5期1699-1711,共13页
The need to develop armour systems to protect against attacks from various sources is increasingly a matter of personal,social and national security.To develop innovative armour systems it is necessary to monitor deve... The need to develop armour systems to protect against attacks from various sources is increasingly a matter of personal,social and national security.To develop innovative armour systems it is necessary to monitor developments being made on the type,technology and performance of the threats(weapons,projectiles,explosives,etc.) Specifically,the use of high protection level helmets on the battlefield is essential.The development of evaluation methods that can predict injuries and trauma is therefore of major importance.However,the risk of injuries or trauma that can arise from induced accelerations is an additional consideration.To develop new materials and layouts for helmets it is necessary to study the effects caused by ballistic impacts in the human head on various scenarios.The use of numerical simulation is a fundamental tool in this process.The work here presented focuses on the use of numerical simulation(finite elements analysis) to predict the consequences of bullet impacts on military helmets on human injuries.The main objectives are to assess the level and probability of head trauma using the Head Injury Criterion,caused by the impact of a 9 mm NATO projectile on a PASGT helmet and to quantify the relevance of projectile plasticity on the whole modelling process.The accelerations derived from the impact phenomenon and the deformations caused on the helmet are evaluated using fully three-dimensional models of the helmet,head,neck and projectile.Impact studies are done at impact angles ranging from 0 to 75°.Results are presented and discussed in terms of HIC and probability of acceleration induced trauma levels.Thorough comparison analyses are done using a rigid and a deformable projectile and it is observed that plastic deformation of the projectile is a significant energy dissipation mechanism in the whole impact process. 展开更多
关键词 Ballistic impact helmet impact PLASTICITY Finite element analysis Injury TRAUMA HIC
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Algorithm of Helmet Wearing Detection Based on AT-YOLO Deep Mode 被引量:9
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作者 Qingyang Zhou Jiaohua Qin +2 位作者 Xuyu Xiang Yun Tan Neal NXiong 《Computers, Materials & Continua》 SCIE EI 2021年第10期159-174,共16页
The existing safety helmet detection methods are mainly based on one-stage object detection algorithms with high detection speed to reach the real-time detection requirements,but they can’t accurately detect small ob... The existing safety helmet detection methods are mainly based on one-stage object detection algorithms with high detection speed to reach the real-time detection requirements,but they can’t accurately detect small objects and objects with obstructions.Therefore,we propose a helmet detection algorithm based on the attention mechanism(AT-YOLO).First of all,a channel attention module is added to the YOLOv3 backbone network,which can adaptively calibrate the channel features of the direction to improve the feature utilization,and a spatial attention module is added to the neck of the YOLOv3 network to capture the correlation between any positions in the feature map so that to increase the receptive field of the network.Secondly,we use DIoU(Distance Intersection over Union)bounding box regression loss function,it not only improving the measurement of bounding box regression loss but also increases the normalized distance loss between the prediction boxes and the target boxes,which makes the network more accurate in detecting small objects and faster in convergence.Finally,we explore the training strategy of the network model,which improves network performance without increasing the inference cost.Experiments show that the mAP of the proposed method reaches 96.5%,and the detection speed can reach 27 fps.Compared with other existing methods,it has better performance in detection accuracy and speed. 展开更多
关键词 Safety helmet detection attention mechanism convolutional neural network training strategies
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Real-time Safety Helmet-wearing Detection Based on Improved YOLOv5 被引量:5
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作者 Yanman Li Jun Zhang +2 位作者 Yang Hu Yingnan Zhao Yi Cao 《Computer Systems Science & Engineering》 SCIE EI 2022年第12期1219-1230,共12页
Safety helmet-wearing detection is an essential part of the intelligentmonitoring system. To improve the speed and accuracy of detection, especiallysmall targets and occluded objects, it presents a novel and efficient... Safety helmet-wearing detection is an essential part of the intelligentmonitoring system. To improve the speed and accuracy of detection, especiallysmall targets and occluded objects, it presents a novel and efficient detectormodel. The underlying core algorithm of this model adopts the YOLOv5 (YouOnly Look Once version 5) network with the best comprehensive detection performance. It is improved by adding an attention mechanism, a CIoU (CompleteIntersection Over Union) Loss function, and the Mish activation function. First,it applies the attention mechanism in the feature extraction. The network can learnthe weight of each channel independently and enhance the information dissemination between features. Second, it adopts CIoU loss function to achieve accuratebounding box regression. Third, it utilizes Mish activation function to improvedetection accuracy and generalization ability. It builds a safety helmet-wearingdetection data set containing more than 10,000 images collected from the Internetfor preprocessing. On the self-made helmet wearing test data set, the averageaccuracy of the helmet detection of the proposed algorithm is 96.7%, which is1.9% higher than that of the YOLOv5 algorithm. It meets the accuracy requirements of the helmet-wearing detection under construction scenarios. 展开更多
关键词 Safety helmet wearing detection object detection deep learning YOLOv5 Attention Mechanism
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A Slip-Line Method for Calculating Extrusion Force of Steel Helmet with Cold Extrusion Moulding 被引量:2
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作者 Guo Jinji Zhao Sheng +1 位作者 Xing Haoxu(Department of Applied Mechanics and Engineering, Zhongshan University,Guangzhou 510275, P. R. China)Guan Guifen Liu Zhijian(The Iron Steel Research institute of Guangdong,Guangzhou 510275, P. R. China) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1999年第2期75-81,共7页
This paper presents the elastic and plastic deformation of the steel helmet with coldextrusion moulding. The plastic streamline of the plastic mould-making process for ellipse thinplate is described. The distribution ... This paper presents the elastic and plastic deformation of the steel helmet with coldextrusion moulding. The plastic streamline of the plastic mould-making process for ellipse thinplate is described. The distribution of slip-line is established based on the plastic streamline. Theextrusion force of plastic moulding of the steel helmet is calculated by using of slip-line method.Furthermore, an applied example is given. 展开更多
关键词 Steel helmet Cold extrusion Plastic streamline slip-line method Extrusion force.
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Helmet-based noninvasive ventilation for acute exacerbation of chronic obstructive pulmonary disease: A case report 被引量:4
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作者 Mi Hwa Park Min Jeong Kim +2 位作者 Ah Jin Kim Man-Jong Lee Jung-Soo Kim 《World Journal of Clinical Cases》 SCIE 2020年第10期1939-1943,共5页
BACKGROUND Noninvasive ventilation(NIV)reduces intubation rates,mortalities,and lengths of hospital and intensive care unit stays in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD).He... BACKGROUND Noninvasive ventilation(NIV)reduces intubation rates,mortalities,and lengths of hospital and intensive care unit stays in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD).Helmet-based NIV is better tolerated than oronasal mask-based ventilation,and thus,allows NIV to be conducted for prolonged periods at higher pressures with minimal air leaks.CASE SUMMARY A 73-year-old man with a previous diagnosis of COPD stage 4 was admitted to our medical intensive care unit with chief complaints of cough,sputum,and dyspnea of several days’duration.For 10 mo,he had been on oxygen at home by day and had used an oronasal mask-based NIV at night.At intensive care unit admission,he breathed using respiratory accessory muscles.Hypercapnia and signs of infection were detected,and infiltration was observed in the right lower lung field by chest radiography.Thus,we diagnosed AECOPD by communityacquired pneumonia.After admission,respiratory distress steadily deteriorated and invasive mechanical ventilation became necessary.However,the patient refused this option,and thus,we selected helmet-based NIV as a salvage treatment.After 3 d of helmet-based NIV,his consciousness level and hypercapnia recovered to his pre-hospitalization level.CONCLUSION Helmet-based NIV could be considered as a salvage treatment when AECOPD patients refuse invasive mechanical ventilation and oronasal mask-based NIV is ineffective. 展开更多
关键词 Acute exacerbation of chronic obstructive pulmonary disease Noninvasive ventilation helmet Case report
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Real-Time Safety Helmet Detection Using Yolov5 at Construction Sites 被引量:4
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作者 Kisaezehra Muhammad Umer Farooq +1 位作者 Muhammad Aslam Bhutto Abdul Karim Kazi 《Intelligent Automation & Soft Computing》 SCIE 2023年第4期911-927,共17页
The construction industry has always remained the economic and social backbone of any country in the world where occupational health and safety(OHS)is of prime importance.Like in other developing countries,this indust... The construction industry has always remained the economic and social backbone of any country in the world where occupational health and safety(OHS)is of prime importance.Like in other developing countries,this industry pays very little,rather negligible attention to OHS practices in Pakistan,resulting in the occurrence of a wide variety of accidents,mishaps,and near-misses every year.One of the major causes of such mishaps is the non-wearing of safety helmets(hard hats)at construction sites where falling objects from a height are unavoid-able.In most cases,this leads to serious brain injuries in people present at the site in general and the workers in particular.It is one of the leading causes of human fatalities at construction sites.In the United States,the Occupational Safety and Health Administration(OSHA)requires construction companies through safety laws to ensure the use of well-defined personal protective equipment(PPE).It has long been a problem to ensure the use of PPE because round-the-clock human monitoring is not possible.However,such monitoring through technological aids or automated tools is very much possible.The present study describes a systema-tic strategy based on deep learning(DL)models built on the You-Only-Look-Once(YOLOV5)architecture that could be used for monitoring workers’hard hats in real-time.It can indicate whether a worker is wearing a hat or not.The proposed system usesfive different models of the YOLOV5,namely YOLOV5n,YOLOv5s,YOLOv5 m,YOLOv5l,and YOLOv5x for object detection with the support of PyTorch,involving 7063 images.The results of the study show that among the DL models,the YOLOV5x has a high performance of 95.8%in terms of the mAP,while the YOLOV5n has the fastest detection speed of 70.4 frames per second(FPS).The proposed model can be successfully used in practice to recognize the hard hat worn by a worker. 展开更多
关键词 Object detection computer-vision personal protective equipment(PPE) deep learning industry revolution(IR)4.0 safety helmet detection
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Detection of Worker’s Safety Helmet and Mask and Identification of Worker Using Deeplearning 被引量:2
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作者 NaeJoung Kwak DongJu Kim 《Computers, Materials & Continua》 SCIE EI 2023年第4期1671-1686,共16页
This paper proposes a method for detecting a helmet for thesafety of workers from risk factors and a mask worn indoors and verifying aworker’s identity while wearing a helmet and mask for security. The proposedmethod... This paper proposes a method for detecting a helmet for thesafety of workers from risk factors and a mask worn indoors and verifying aworker’s identity while wearing a helmet and mask for security. The proposedmethod consists of a part for detecting the worker’s helmet and mask and apart for verifying the worker’s identity. An algorithm for helmet and maskdetection is generated by transfer learning of Yolov5’s s-model and m-model.Both models are trained by changing the learning rate, batch size, and epoch.The model with the best performance is selected as the model for detectingmasks and helmets. At a learning rate of 0.001, a batch size of 32, and anepoch of 200, the s-model showed the best performance with a mAP of0.954, and this was selected as an optimal model. The worker’s identificationalgorithm consists of a facial feature extraction part and a classifier partfor the worker’s identification. The algorithm for facial feature extraction isgenerated by transfer learning of Facenet, and SVMis used as the classifier foridentification. The proposed method makes trained models using two datasets,a masked face dataset with only a masked face, and a mixed face datasetwith both a masked face and an unmasked face. And the model with the bestperformance among the trained models was selected as the optimal model foridentification when using a mask. As a result of the experiment, the model bytransfer learning of Facenet and SVM using a mixed face dataset showed thebest performance. When the optimal model was tested with a mixed dataset,it showed an accuracy of 95.4%. Also, the proposed model was evaluated asdata from 500 images of taking 10 people with a mobile phone. The resultsshowed that the helmet and mask were detected well and identification wasalso good. 展开更多
关键词 MASK PPE safety helmet Yolo Facenet
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Detection of Safety Helmet-Wearing Based on the YOLO_CA Model 被引量:2
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作者 Xiaoqin Wu Songrong Qian Ming Yang 《Computers, Materials & Continua》 SCIE EI 2023年第12期3349-3366,共18页
Safety helmets can reduce head injuries from object impacts and lower the probability of safety accidents,as well as being of great significance to construction safety.However,for a variety of reasons,construction wor... Safety helmets can reduce head injuries from object impacts and lower the probability of safety accidents,as well as being of great significance to construction safety.However,for a variety of reasons,construction workers nowadays may not strictly enforce the rules of wearing safety helmets.In order to strengthen the safety of construction site,the traditional practice is to manage it through methods such as regular inspections by safety officers,but the cost is high and the effect is poor.With the popularization and application of construction site video monitoring,manual video monitoring has been realized for management,but the monitors need to be on duty at all times,and thus are prone to negligence.Therefore,this study establishes a lightweight model YOLO_CA based on YOLOv5 for the automatic detection of construction workers’helmet wearing,which overcomes the shortcomings of the current manual monitoring methods that are inefficient and expensive.The coordinate attention(CA)addition to the YOLOv5 backbone strengthens detection accuracy in complex scenes by extracting critical information and suppressing non-critical information.Further parameter compression with deeply separable convolution(DWConv).In addition,to improve the feature representation speed,we swap out C3 with a Ghost module,which decreases the floating-point operations needed for feature channel fusion,and CIOU_Loss was substituted with EIOU_Loss to enhance the algorithm’s localization accuracy.Therefore,the original model needs to be improved so as to enhance the detection of safety helmets.The experimental results show that the YOLO_CA model achieves good results in all indicators compared with the mainstream model.Compared with the original model,the mAP value of the optimized model increased by 1.13%,GFLOPs cut down by 17.5%,and there is a 6.84%decrease in the total model parameters,furthermore,the weight size cuts down by 4.26%,FPS increased by 39.58%,and the detection effect and model size of this model can meet the requirements of lightweight embedding. 展开更多
关键词 Safety helmet CA YOLOv5 ghost module
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Calculation and Test of Hitting Force of Firing Bullet on the Bulletproof Helmet 被引量:1
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作者 Jinji, Guo Haoxu, Xing +3 位作者 Gao, Yang Chengbai, Wu Jincai, Pei Zhijian, Liu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1998年第3期69-76,共8页
In this paper the hit force of firing bullet on bulletproof helmet has been computed and the test device has been described. The device is divided into two parts: 1) The bullet, helmet and mould are in one system, u... In this paper the hit force of firing bullet on bulletproof helmet has been computed and the test device has been described. The device is divided into two parts: 1) The bullet, helmet and mould are in one system, using moment theorem to calculate the hit force; 2) The mould, sensor and support pole are in one system, using the method in reference [1] that measures the dynamic strain and displacement of simulate target of bulletproof clothes. We compute the transfigure energy and momentum energy when hitting the mould, the work done by the sensor and the expend energy of support pole. We get the hit force of helmet using energy balance principle. The result is according with the test and has been used to design the GGK93T bulletproof helmet and other serial products. 展开更多
关键词 Bulletproof helmet Bullet hit force Head mould Force sensor Hitting energy
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Thermoregulatory function and sexual dimorphism of the throat sack in Helmeted Guineafowl(Numida meleagris)across Africa 被引量:1
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作者 Johann H.Van Niekerk Rodrigo Megía-Palma Giovanni Forcina 《Avian Research》 SCIE CSCD 2022年第3期239-248,共10页
The responses of ground-dwelling birds to heat and cold stress encompass a variety of behavioural,physiological and even morphological mechanisms.However,the role of glabrous skin in this respect has been marginally a... The responses of ground-dwelling birds to heat and cold stress encompass a variety of behavioural,physiological and even morphological mechanisms.However,the role of glabrous skin in this respect has been marginally addressed so far.The Helmeted Guineafowl(Numida meleagris)is a landfowl distributed across Sub-Saharan Africa with eight traditionally recognised extant subspecies.Among the most prominent morphological traits underlying intraspecific variability are size and pigmentation of the bare throat skin(or sack),which might be related to the different habitats and environmental conditions across its wide range.In order to explore the Helmeted Guineafowl range-wide sack variation and pigmentation in relation to thermoregulation and sexual signalling,we collected morphometric and environmental information for N.m.coronata integrating field data with the inspection of photographic material encompassing seven subspecies and environmental information from their habitats.Field data evidenced that sack size was significantly correlated with ambient temperature,thus pointing to a likely involvement of the throat sack in thermoregulation.When the pictorial data from all subspecies were pooled,sack size correlated negatively with biomass,rainfall and humidity,while a positive correlation was found with annual solar irradiation.Sack size correlated positively with monthly temperature variation among the bluethroated subspecies from southern Africa as opposed to the black-throated subspecies ranging north to Zambia and Mozambique.Still,in this latter group the sack was often larger during winter months,possibly to maximise solar radiation absorbance.Noteworthy,sack size was related to sex dimorphism in two subspecies.Sack morphology and colour in the Helmeted Guineafowl likely modulate body temperature by evaporative cooling or heating upon needs,but in some subspecies it is also seemingly related to sexual signalling.Additional studies are needed to fully understand the multifunctionality of this important morphological feature in this species. 展开更多
关键词 Evaporative cooling helmeted guineafowl Sexual size dimorphism Sub-Saharan Africa THERMOREGULATION Throat sack
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Application of Virtual Reconstruction 3D-Printed External Fixation Helmet in Early Functional Treatment of Facial Fracture 被引量:1
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作者 GE Weiwen WANG Yun +5 位作者 GE Kui WU Jiajun FAN Jingrian YANG Tianye WANG Qi XU Bing 《Journal of Shanghai Jiaotong university(Science)》 EI 2021年第3期368-371,共4页
Facial fracture repair is time-dependent.Early reduction and fixation after trauma help with later repair.Abnormal healing caused by delayed repair increases not only the difficulty of reconstruction,but also the risk... Facial fracture repair is time-dependent.Early reduction and fixation after trauma help with later repair.Abnormal healing caused by delayed repair increases not only the difficulty of reconstruction,but also the risk of aesthetic or functional defects.Digital technology was used to model local trauma in three dimensions.The fracture fragments were reset,and the facial shape was reconstructed on the reset model.After resampling,3D printing was used to construct a personalised external fixation helmet.Combined with the posterior nasal passage lift reduction technique,early reduction of the mid-face fractures was performed.Through the early application of a 3D-printed personalised external fixation helmet to a patient with a comprehensive fracture,the helmet manufacturing process and application methods were introduced,and the effect of this application was investigated.In the treatment of facial fractures,the early application of a 3D-printed personalised external fixation helmet is conducive to fracture reduction and fixation and reduces the difficulty of later reconstruction. 展开更多
关键词 external fixation helmet facial fracture functional reconstruction 3D printing
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Preventable head and facial injuries by providing free bicycle helmets and education to preschool children in a head start program
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作者 Thein Hlaing Zhu Mary O. Aaland +3 位作者 Connie Kerrigan Renee Schiebel Heather Henry Lisa Hollister 《Health》 2011年第11期689-697,共9页
The objectives of the study were to determine helmet use rates, incidence rates (IRs) of head and facial injuries for population attributable fraction (PAF) estimation, and to elucidate the magnitude of and changes in... The objectives of the study were to determine helmet use rates, incidence rates (IRs) of head and facial injuries for population attributable fraction (PAF) estimation, and to elucidate the magnitude of and changes in PAFs as the result of helmet use changes among preschool children. A study consisting of cross-sectional (survey) and longitudinal (follow-up) component was designed by including a randomly selected group of participants (n = 322) from 10 Head Start sites provided with free bicycle helmets along with a subgroup of prior helmet owners (n = 68) from the other random group (n = 285). All participants received bicycle helmet education. Helmet use surveys were conducted in May (1st Survey) and November 2008 (2nd Survey). The helmet owners were followed up to determine IRs, and incidence rate ratios (IRRs) for head and facial injuries. PAFs were computed using IRs as well as helmet use rates and IRRs. Helmet use rates increased significantly from the 1st to the 2nd Survey. The mean follow-up person-time was 5 months. The IRs for head, face (all portions), and face (upper/mid portions) injuries were higher in non-helmeted than helmeted riders. By using IRs, PAFs for the 3 injuries among the riders in both groups of helmet owners were 77%, 22%, and 32% respectively. The PAFs for each of the above injuries decreased by about 10% as helmet use rates increased. The magnitude of and changes in preventable head and facial injuries following free bicycle helmet distribution and education among helmeted riders was elucidated in this Head Start preschool children population. 展开更多
关键词 HEAD INJURY FACIAL INJURY Free helmet Distribution HEAD Start PRESCHOOL Children PAF
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An Examination of Concussion Injury Rates in Various Models of Football Helmets in NCAA Football Athletes
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作者 Ryan Moran Tracey Covassin 《Journal of Sports Science》 2015年第1期29-34,共6页
While newer, advanced helmet models have been designed with the intentions of decreasing concussions, very little research exists on injury rates in various football helmets at the collegiate level. The aim of this st... While newer, advanced helmet models have been designed with the intentions of decreasing concussions, very little research exists on injury rates in various football helmets at the collegiate level. The aim of this study was to examine concussion injury rates in various models of football helmets in collegiate football athletes. In addition, to compare injury rates of newer, advanced football helmets to older, traditional helmets among collegiate football athletes, a total of 209 concussions and 563,701 AEs (athlete-exposures) among 2,107 collegiate football athletes in seven helmet models were included in the analyses. Concussion injury rates revealed that the Riddell Revolution~ had the highest rate of 0.41 concussions per 1,000 AEs. The Schutt ION 4DTM helmet had the lowest rate of 0.25 concussions per 1,000 AEs. These newer helmet models did not significantly differ from one another (P = 0.74), however, all models significantly differed from the older, traditional helmet model (P 〈 0.001). The findings of this study suggest that concussion rates do not differ between newer and more advanced helmet models. More importantly, there are currently no helmets available to prevent concussions from occurring in football athletes. 展开更多
关键词 FOOTBALL (American) concussion injury rates helmets.
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Research on the Application of Helmet Detection Based on YOLOv4
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作者 Yongze Ji Yu Cao +1 位作者 Xu Cheng Qiong Zhang 《Journal of Computer and Communications》 2022年第8期129-139,共11页
Helmets are one of the important measures to ensure the safety of construction workers. Because the harm caused by not wearing safety helmets as required is great, the wearing of safety helmets has also attracted more... Helmets are one of the important measures to ensure the safety of construction workers. Because the harm caused by not wearing safety helmets as required is great, the wearing of safety helmets has also attracted more and more people’s attention. At present, the main method of helmet detection is the YOLO series of algorithms. They often only focus on detection accuracy, ignoring the actual situation during deployment, that is, a balance between accuracy and speed is required. Therefore, this paper proposes a helmet detection application based on YOLOv4 algorithm, and combined with the MobileNet network, it has achieved good results in terms of detection accuracy and speed. Through transfer learning and tuning parameters, the mAP and FPS values detected in this paper on the public safety helmet datasets are 94.47% and 27.36%, which exceed the research work of some similar papers. This paper also combines YOLOv4 and MobileNetv3 networks to propose a mobileNet-based YOLOv4 helmet detection application. Its mAP and FPS values are 91.47% and 42.58%, respectively, which meet the accuracy and real-time requirements of current hardware deployment. 展开更多
关键词 YOLOv4 helmet Target Detection MobileNet
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