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EHDC-YOLO: Enhancing Object Detection for UAV Imagery via Multi-Scale Edge and Detail Capture
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作者 Zhiyong Deng Yanchen Ye Jiangling Guo 《Computers, Materials & Continua》 2026年第1期1665-1682,共18页
With the rapid expansion of drone applications,accurate detection of objects in aerial imagery has become crucial for intelligent transportation,urban management,and emergency rescue missions.However,existing methods ... With the rapid expansion of drone applications,accurate detection of objects in aerial imagery has become crucial for intelligent transportation,urban management,and emergency rescue missions.However,existing methods face numerous challenges in practical deployment,including scale variation handling,feature degradation,and complex backgrounds.To address these issues,we propose Edge-enhanced and Detail-Capturing You Only Look Once(EHDC-YOLO),a novel framework for object detection in Unmanned Aerial Vehicle(UAV)imagery.Based on the You Only Look Once version 11 nano(YOLOv11n)baseline,EHDC-YOLO systematically introduces several architectural enhancements:(1)a Multi-Scale Edge Enhancement(MSEE)module that leverages multi-scale pooling and edge information to enhance boundary feature extraction;(2)an Enhanced Feature Pyramid Network(EFPN)that integrates P2-level features with Cross Stage Partial(CSP)structures and OmniKernel convolutions for better fine-grained representation;and(3)Dynamic Head(DyHead)with multi-dimensional attention mechanisms for enhanced cross-scale modeling and perspective adaptability.Comprehensive experiments on the Vision meets Drones for Detection(VisDrone-DET)2019 dataset demonstrate that EHDC-YOLO achieves significant improvements,increasing mean Average Precision(mAP)@0.5 from 33.2%to 46.1%(an absolute improvement of 12.9 percentage points)and mAP@0.5:0.95 from 19.5%to 28.0%(an absolute improvement of 8.5 percentage points)compared with the YOLOv11n baseline,while maintaining a reasonable parameter count(2.81 M vs the baseline’s 2.58 M).Further ablation studies confirm the effectiveness of each proposed component,while visualization results highlight EHDC-YOLO’s superior performance in detecting objects and handling occlusions in complex drone scenarios. 展开更多
关键词 UAV imagery object detection multi-scale feature fusion edge enhancement detail preservation YOLO feature pyramid network attention mechanism
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Research on Camouflage Target Detection Method Based on Edge Guidance and Multi-Scale Feature Fusion
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作者 Tianze Yu Jianxun Zhang Hongji Chen 《Computers, Materials & Continua》 2026年第4期1676-1697,共22页
Camouflaged Object Detection(COD)aims to identify objects that share highly similar patterns—such as texture,intensity,and color—with their surrounding environment.Due to their intrinsic resemblance to the backgroun... Camouflaged Object Detection(COD)aims to identify objects that share highly similar patterns—such as texture,intensity,and color—with their surrounding environment.Due to their intrinsic resemblance to the background,camouflaged objects often exhibit vague boundaries and varying scales,making it challenging to accurately locate targets and delineate their indistinct edges.To address this,we propose a novel camouflaged object detection network called Edge-Guided and Multi-scale Fusion Network(EGMFNet),which leverages edge-guided multi-scale integration for enhanced performance.The model incorporates two innovative components:a Multi-scale Fusion Module(MSFM)and an Edge-Guided Attention Module(EGA).These designs exploit multi-scale features to uncover subtle cues between candidate objects and the background while emphasizing camouflaged object boundaries.Moreover,recognizing the rich contextual information in fused features,we introduce a Dual-Branch Global Context Module(DGCM)to refine features using extensive global context,thereby generatingmore informative representations.Experimental results on four benchmark datasets demonstrate that EGMFNet outperforms state-of-the-art methods across five evaluation metrics.Specifically,on COD10K,our EGMFNet-P improves F_(β)by 4.8 points and reduces mean absolute error(MAE)by 0.006 compared with ZoomNeXt;on NC4K,it achieves a 3.6-point increase in F_(β).OnCAMO and CHAMELEON,it obtains 4.5-point increases in F_(β),respectively.These consistent gains substantiate the superiority and robustness of EGMFNet. 展开更多
关键词 Camouflaged object detection multi-scale feature fusion edge-guided image segmentation
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SIM-Net:A Multi-Scale Attention-Guided Deep Learning Framework for High-Precision PCB Defect Detection
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作者 Ping Fang Mengjun Tong 《Computers, Materials & Continua》 2026年第4期1754-1770,共17页
Defect detection in printed circuit boards(PCB)remains challenging due to the difficulty of identifying small-scale defects,the inefficiency of conventional approaches,and the interference from complex backgrounds.To ... Defect detection in printed circuit boards(PCB)remains challenging due to the difficulty of identifying small-scale defects,the inefficiency of conventional approaches,and the interference from complex backgrounds.To address these issues,this paper proposes SIM-Net,an enhanced detection framework derived from YOLOv11.The model integrates SPDConv to preserve fine-grained features for small object detection,introduces a novel convolutional partial attention module(C2PAM)to suppress redundant background information and highlight salient regions,and employs a multi-scale fusion network(MFN)with a multi-grain contextual module(MGCT)to strengthen contextual representation and accelerate inference.Experimental evaluations demonstrate that SIM-Net achieves 92.4%mAP,92%accuracy,and 89.4%recall with an inference speed of 75.1 FPS,outperforming existing state-of-the-art methods.These results confirm the robustness and real-time applicability of SIM-Net for PCB defect inspection. 展开更多
关键词 Deep learning small object detection PCB defect detection attention mechanism multi-scale fusion network
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A New method for selecting multi-scale road network objects 被引量:1
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作者 Wang Yanhui 《High Technology Letters》 EI CAS 2011年第4期407-413,共7页
Aimed at solving the problems of road network object selection at any unknown scale, the existing methods on object selection are integrated and extended in this paper, and a new object interpolation method is propose... Aimed at solving the problems of road network object selection at any unknown scale, the existing methods on object selection are integrated and extended in this paper, and a new object interpolation method is proposed, which reflects the inheritable and transferable characteristics of related information among multi-scale representation objects, and takes the attribute effects into account. Then the basic idea, the overall framework and the technical flow of the interpolation are put forward, at the samet:me synthetical weight function of the interpolation method is defined and described. The method and technical strategies of object selection are extended, and the key problems are solved, including the dejign of the objective quantitative and structural selections based on the weight values, the interpolation experiment strategies and technical flows, the result of the test shows that the object interpolation method not only inherits the objects at smaller scales, but also takes the attribute effect into account when deriving objects from larger scales according to the road importance, which is a guarantee to objective selection of the road objects at middle scales. 展开更多
关键词 multi-scale representation object interpolation object selection synthetic weight
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YOLO-MFD:Remote Sensing Image Object Detection with Multi-Scale Fusion Dynamic Head
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作者 Zhongyuan Zhang Wenqiu Zhu 《Computers, Materials & Continua》 SCIE EI 2024年第5期2547-2563,共17页
Remote sensing imagery,due to its high altitude,presents inherent challenges characterized by multiple scales,limited target areas,and intricate backgrounds.These inherent traits often lead to increased miss and false... Remote sensing imagery,due to its high altitude,presents inherent challenges characterized by multiple scales,limited target areas,and intricate backgrounds.These inherent traits often lead to increased miss and false detection rates when applying object recognition algorithms tailored for remote sensing imagery.Additionally,these complexities contribute to inaccuracies in target localization and hinder precise target categorization.This paper addresses these challenges by proposing a solution:The YOLO-MFD model(YOLO-MFD:Remote Sensing Image Object Detection withMulti-scale Fusion Dynamic Head).Before presenting our method,we delve into the prevalent issues faced in remote sensing imagery analysis.Specifically,we emphasize the struggles of existing object recognition algorithms in comprehensively capturing critical image features amidst varying scales and complex backgrounds.To resolve these issues,we introduce a novel approach.First,we propose the implementation of a lightweight multi-scale module called CEF.This module significantly improves the model’s ability to comprehensively capture important image features by merging multi-scale feature information.It effectively addresses the issues of missed detection and mistaken alarms that are common in remote sensing imagery.Second,an additional layer of small target detection heads is added,and a residual link is established with the higher-level feature extraction module in the backbone section.This allows the model to incorporate shallower information,significantly improving the accuracy of target localization in remotely sensed images.Finally,a dynamic head attentionmechanism is introduced.This allows themodel to exhibit greater flexibility and accuracy in recognizing shapes and targets of different sizes.Consequently,the precision of object detection is significantly improved.The trial results show that the YOLO-MFD model shows improvements of 6.3%,3.5%,and 2.5%over the original YOLOv8 model in Precision,map@0.5 and map@0.5:0.95,separately.These results illustrate the clear advantages of the method. 展开更多
关键词 object detection YOLOv8 multi-scale attention mechanism dynamic detection head
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MSC-YOLO:Improved YOLOv7 Based on Multi-Scale Spatial Context for Small Object Detection in UAV-View
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作者 Xiangyan Tang Chengchun Ruan +2 位作者 Xiulai Li Binbin Li Cebin Fu 《Computers, Materials & Continua》 SCIE EI 2024年第4期983-1003,共21页
Accurately identifying small objects in high-resolution aerial images presents a complex and crucial task in thefield of small object detection on unmanned aerial vehicles(UAVs).This task is challenging due to variati... Accurately identifying small objects in high-resolution aerial images presents a complex and crucial task in thefield of small object detection on unmanned aerial vehicles(UAVs).This task is challenging due to variations inUAV flight altitude,differences in object scales,as well as factors like flight speed and motion blur.To enhancethe detection efficacy of small targets in drone aerial imagery,we propose an enhanced You Only Look Onceversion 7(YOLOv7)algorithm based on multi-scale spatial context.We build the MSC-YOLO model,whichincorporates an additional prediction head,denoted as P2,to improve adaptability for small objects.We replaceconventional downsampling with a Spatial-to-Depth Convolutional Combination(CSPDC)module to mitigatethe loss of intricate feature details related to small objects.Furthermore,we propose a Spatial Context Pyramidwith Multi-Scale Attention(SCPMA)module,which captures spatial and channel-dependent features of smalltargets acrossmultiple scales.This module enhances the perception of spatial contextual features and the utilizationof multiscale feature information.On the Visdrone2023 and UAVDT datasets,MSC-YOLO achieves remarkableresults,outperforming the baseline method YOLOv7 by 3.0%in terms ofmean average precision(mAP).The MSCYOLOalgorithm proposed in this paper has demonstrated satisfactory performance in detecting small targets inUAV aerial photography,providing strong support for practical applications. 展开更多
关键词 Small object detection YOLOv7 multi-scale attention spatial context
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METHOD OF CENTERS ALGORITHM FORMULTI-OBJECTIVE PROGRAMMING PROBLEMS
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作者 Tarek Emam 《Acta Mathematica Scientia》 SCIE CSCD 2009年第5期1128-1142,共15页
In this paper, we consider a method of centers for solving multi-objective programming problems, where the objective functions involved are concave functions and the set of feasible points is convex. The algorithm is ... In this paper, we consider a method of centers for solving multi-objective programming problems, where the objective functions involved are concave functions and the set of feasible points is convex. The algorithm is defined so that the sub-problems that must be solved during its execution may be solved by finite-step procedures. Conditions are given under which the algorithm generates sequences of feasible points and constraint multiplier vectors that have accumulation points satisfying the KKT conditions. Finally, we establish convergence of the proposed method of centers algorithm for solving multiobjective programming problems. 展开更多
关键词 method of centers MULTI-objective CONVERGENCE approximated efficient solution
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Hybrid receptive field network for small object detection on drone view 被引量:1
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作者 Zhaodong CHEN Hongbing JI +2 位作者 Yongquan ZHANG Wenke LIU Zhigang ZHU 《Chinese Journal of Aeronautics》 2025年第2期322-338,共17页
Drone-based small object detection is of great significance in practical applications such as military actions, disaster rescue, transportation, etc. However, the severe scale differences in objects captured by drones... Drone-based small object detection is of great significance in practical applications such as military actions, disaster rescue, transportation, etc. However, the severe scale differences in objects captured by drones and lack of detail information for small-scale objects make drone-based small object detection a formidable challenge. To address these issues, we first develop a mathematical model to explore how changing receptive fields impacts the polynomial fitting results. Subsequently, based on the obtained conclusions, we propose a simple but effective Hybrid Receptive Field Network (HRFNet), whose modules include Hybrid Feature Augmentation (HFA), Hybrid Feature Pyramid (HFP) and Dual Scale Head (DSH). Specifically, HFA employs parallel dilated convolution kernels of different sizes to extend shallow features with different receptive fields, committed to improving the multi-scale adaptability of the network;HFP enhances the perception of small objects by capturing contextual information across layers, while DSH reconstructs the original prediction head utilizing a set of high-resolution features and ultrahigh-resolution features. In addition, in order to train HRFNet, the corresponding dual-scale loss function is designed. Finally, comprehensive evaluation results on public benchmarks such as VisDrone-DET and TinyPerson demonstrate the robustness of the proposed method. Most impressively, the proposed HRFNet achieves a mAP of 51.0 on VisDrone-DET with 29.3 M parameters, which outperforms the extant state-of-the-art detectors. HRFNet also performs excellently in complex scenarios captured by drones, achieving the best performance on the CS-Drone dataset we built. 展开更多
关键词 Drone remote sensing object detection on drone view Small object detector Hybrid receptive field Feature pyramid network Feature augmentation multi-scale object detection
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DDFNet:real-time salient object detection with dual-branch decoding fusion for steel plate surface defects
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作者 Tao Wang Wang-zhe Du +5 位作者 Xu-wei Li Hua-xin Liu Yuan-ming Liu Xiao-miao Niu Ya-xing Liu Tao Wang 《Journal of Iron and Steel Research International》 2025年第8期2421-2433,共13页
A novel dual-branch decoding fusion convolutional neural network model(DDFNet)specifically designed for real-time salient object detection(SOD)on steel surfaces is proposed.DDFNet is based on a standard encoder–decod... A novel dual-branch decoding fusion convolutional neural network model(DDFNet)specifically designed for real-time salient object detection(SOD)on steel surfaces is proposed.DDFNet is based on a standard encoder–decoder architecture.DDFNet integrates three key innovations:first,we introduce a novel,lightweight multi-scale progressive aggregation residual network that effectively suppresses background interference and refines defect details,enabling efficient salient feature extraction.Then,we propose an innovative dual-branch decoding fusion structure,comprising the refined defect representation branch and the enhanced defect representation branch,which enhance accuracy in defect region identification and feature representation.Additionally,to further improve the detection of small and complex defects,we incorporate a multi-scale attention fusion module.Experimental results on the public ESDIs-SOD dataset show that DDFNet,with only 3.69 million parameters,achieves detection performance comparable to current state-of-the-art models,demonstrating its potential for real-time industrial applications.Furthermore,our DDFNet-L variant consistently outperforms leading methods in detection performance.The code is available at https://github.com/13140W/DDFNet. 展开更多
关键词 Steel plate surface defect Real-time detection Salient object detection Dual-branch decoder multi-scale attention fusion multi-scale residual fusion
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Coupling the Power of YOLOv9 with Transformer for Small Object Detection in Remote-Sensing Images
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作者 Mohammad Barr 《Computer Modeling in Engineering & Sciences》 2025年第4期593-616,共24页
Recent years have seen a surge in interest in object detection on remote sensing images for applications such as surveillance andmanagement.However,challenges like small object detection,scale variation,and the presen... Recent years have seen a surge in interest in object detection on remote sensing images for applications such as surveillance andmanagement.However,challenges like small object detection,scale variation,and the presence of closely packed objects in these images hinder accurate detection.Additionally,the motion blur effect further complicates the identification of such objects.To address these issues,we propose enhanced YOLOv9 with a transformer head(YOLOv9-TH).The model introduces an additional prediction head for detecting objects of varying sizes and swaps the original prediction heads for transformer heads to leverage self-attention mechanisms.We further improve YOLOv9-TH using several strategies,including data augmentation,multi-scale testing,multi-model integration,and the introduction of an additional classifier.The cross-stage partial(CSP)method and the ghost convolution hierarchical graph(GCHG)are combined to improve detection accuracy by better utilizing feature maps,widening the receptive field,and precisely extracting multi-scale objects.Additionally,we incorporate the E-SimAM attention mechanism to address low-resolution feature loss.Extensive experiments on the VisDrone2021 and DIOR datasets demonstrate the effectiveness of YOLOv9-TH,showing good improvement in mAP compared to the best existing methods.The YOLOv9-TH-e achieved 54.2% of mAP50 on the VisDrone2021 dataset and 92.3% of mAP on the DIOR dataset.The results confirmthemodel’s robustness and suitability for real-world applications,particularly for small object detection in remote sensing images. 展开更多
关键词 Remote sensing images YOLOv9-TH multi-scale object detection transformer heads VisDrone2021 dataset
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基于逼近理想解排序法的综合能源系统多目标优化调度方法
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作者 王芳 江伟建 蒋熙蕴 《电子设计工程》 2026年第4期109-114,共6页
为突破传统综合能源系统优化调度方法的单目标和统一调度尺度限制,提升系统效率、经济性与可持续性,提出一种基于逼近理想解排序法与强化学习相结合的多目标优化调度方法。通过设置多目标奖励函数,结合混合时间尺度调度策略,构建了基于... 为突破传统综合能源系统优化调度方法的单目标和统一调度尺度限制,提升系统效率、经济性与可持续性,提出一种基于逼近理想解排序法与强化学习相结合的多目标优化调度方法。通过设置多目标奖励函数,结合混合时间尺度调度策略,构建了基于近端策略优化的智能化调度模型。实验结果表明,所提算法在训练次数少于500次时迅速超越其他算法并进入稳态,优化后的成本、碳排放和㶲效率分别为49 582.4元、4 933.3 kg和60.9%,调整时间仅为1 s。混合时间尺度智能体在碳排放和㶲效率方面优于单一时间尺度智能体。该方法为现代能源系统调度提供了新的智能化路径,具有较高的应用价值。 展开更多
关键词 逼近理想解排序法 能源 多目标 调度
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基于NSGA-Ⅱ算法的油底壳轻量化设计
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作者 郭文强 郭永正 +1 位作者 闫祥海 徐立友 《车用发动机》 北大核心 2026年第1期57-63,70,共8页
传统油底壳设计往往采用金属材料,为了充分发挥油底壳的性能,提出基于NSGA-Ⅱ算法的油底壳轻量化设计方法。首先,建立油底壳的有限元模型,并进行自由模态分析,对原钢制油底壳进行模态测试,对比分析前六阶模态频率及振型,验证有限元模型... 传统油底壳设计往往采用金属材料,为了充分发挥油底壳的性能,提出基于NSGA-Ⅱ算法的油底壳轻量化设计方法。首先,建立油底壳的有限元模型,并进行自由模态分析,对原钢制油底壳进行模态测试,对比分析前六阶模态频率及振型,验证有限元模型的准确性。其次,基于等刚度近似理论,对铝合金材料油底壳选取7个典型壁厚作为设计变量,以油底壳的一阶固有频率和质量为优化目标,应用最优拉丁超立方试验设计方法对设计变量进行贡献度分析。最后,基于Isight参数优化软件分别构建优化目标与影响因素之间的RBF近似模型和RSM近似模型,经分析对比之后选择RSM近似模型进行后续优化,基于NSGA-Ⅱ算法在代理模型内进行全局寻优,获取了一组使油底壳一阶模态频率和质量最优的预测值。研究结果表明,RSM近似模型的预测值与仿真试验结果基本吻合,优化后一阶模态频率提升22.9%,质量降低37.6%。 展开更多
关键词 油底壳 等刚度替换 近似模型 多目标优化 轻量化设计
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Neighborhood fusion-based hierarchical parallel feature pyramid network for object detection 被引量:3
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作者 Mo Lingfei Hu Shuming 《Journal of Southeast University(English Edition)》 EI CAS 2020年第3期252-263,共12页
In order to improve the detection accuracy of small objects,a neighborhood fusion-based hierarchical parallel feature pyramid network(NFPN)is proposed.Unlike the layer-by-layer structure adopted in the feature pyramid... In order to improve the detection accuracy of small objects,a neighborhood fusion-based hierarchical parallel feature pyramid network(NFPN)is proposed.Unlike the layer-by-layer structure adopted in the feature pyramid network(FPN)and deconvolutional single shot detector(DSSD),where the bottom layer of the feature pyramid network relies on the top layer,NFPN builds the feature pyramid network with no connections between the upper and lower layers.That is,it only fuses shallow features on similar scales.NFPN is highly portable and can be embedded in many models to further boost performance.Extensive experiments on PASCAL VOC 2007,2012,and COCO datasets demonstrate that the NFPN-based SSD without intricate tricks can exceed the DSSD model in terms of detection accuracy and inference speed,especially for small objects,e.g.,4%to 5%higher mAP(mean average precision)than SSD,and 2%to 3%higher mAP than DSSD.On VOC 2007 test set,the NFPN-based SSD with 300×300 input reaches 79.4%mAP at 34.6 frame/s,and the mAP can raise to 82.9%after using the multi-scale testing strategy. 展开更多
关键词 computer vision deep convolutional neural network object detection hierarchical parallel feature pyramid network multi-scale feature fusion
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双边磁场调制永磁直线电机推力特性优化设计 被引量:1
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作者 缪仲翠 张磊 +2 位作者 苏乙 张慧 李燕 《电机与控制学报》 北大核心 2025年第2期146-159,共14页
针对永磁直线电机存在的推力波动大以及永磁体利用率低等问题,从结构设计方面着手,提出一种采用扇形Halbach交替极磁极结构的双边长次级磁场调制永磁直线电机(BLSMFMPMLM),并对其进行优化设计。首先,通过有限元法分析BLSMFMPMLM分别采用... 针对永磁直线电机存在的推力波动大以及永磁体利用率低等问题,从结构设计方面着手,提出一种采用扇形Halbach交替极磁极结构的双边长次级磁场调制永磁直线电机(BLSMFMPMLM),并对其进行优化设计。首先,通过有限元法分析BLSMFMPMLM分别采用3种不同Halbach磁极结构的气隙磁场谐波成分、平均推力和推力波动等电磁性能进行计算分析;其次,通过建立推力特性的解析模型和Taguchi法筛选出对推力特性影响较大的参数,利用组合近似模型(ES)结合多目标优化算法对关键参数进行优化以提高电机推力特性,获得多组Pareto最优解;最后,选取综合性能较优的解搭建仿真模型分析电机性能的改善效果和验证设计方法的实用性。结果表明:扇形Halbach交替极磁极结构永磁体利用率更高,具有实用价值;优化后的BLSMFMPMLM平均推力提升了26.82%,并其使得推力波动减小了24.66%,该研究为永磁直线电机的性能改善提供了有效方法。 展开更多
关键词 永磁直线电机 磁场调制 HALBACH阵列 交替极 推力特性 有限元 组合近似模型 多目标优化
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某园林工程挖掘机驾驶室轻量化设计
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作者 洪婷婷 冯辰 朱立源 《机械设计与制造》 北大核心 2025年第5期290-293,300,共5页
挖掘机驾驶室是保护驾驶员生命安全的重要机构,其轻量化设计的前提是必须满足对驾驶员的安全保护,因此,论文首先通过有限元仿真对驾驶室的侧翻与落物保护机构(ROPS&FOPS)的安全性能进行了模拟,利用安全性能测试验证该模型的有效性... 挖掘机驾驶室是保护驾驶员生命安全的重要机构,其轻量化设计的前提是必须满足对驾驶员的安全保护,因此,论文首先通过有限元仿真对驾驶室的侧翻与落物保护机构(ROPS&FOPS)的安全性能进行了模拟,利用安全性能测试验证该模型的有效性。其次,对驾驶室的ROPS&FOPS结构进行试验设计,基于仿真结果建立了近似模型,并以驾驶室的ROPS&FOPS结构厚度为变量,最小质量和最大扭转刚度为目标进行多目标优化。结果表明,在满足安全性能的条件下,可以将驾驶室的质量减轻11.7%,轻量化效果显著,为驾驶室的轻量化设计研制提供了理论依据。 展开更多
关键词 驾驶室 安全性能 轻量化设计 近似模型 多目标优化
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道路网中针对多目标决策的兴趣点高效查询算法
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作者 李松 杨晓龙 +1 位作者 靳海鹏 张丽平 《西安交通大学学报》 北大核心 2025年第4期148-157,共10页
为了解决道路网中利用多目标决策技术进行兴趣点推荐和高效位置查询的问题,针对由于数据规模增加产生大量近似数据,导致传统多目标决策技术在道路网环境下查询效率和可用性方面较低的问题,提出了一种道路网广义近似Skyline查询算法。首... 为了解决道路网中利用多目标决策技术进行兴趣点推荐和高效位置查询的问题,针对由于数据规模增加产生大量近似数据,导致传统多目标决策技术在道路网环境下查询效率和可用性方面较低的问题,提出了一种道路网广义近似Skyline查询算法。首先基于兴趣点的维度相似性和道路网近似性构建近似集和独立点,并根据兴趣点特性设计相应的剪枝策略;随后,通过近似集和独立点重构数据集,根据剪枝策略过滤掉当查询位置移动时对查询结果无影响的兴趣点,并构建AA-R*-Tree索引以提升查询效率;最后,根据兴趣点的近似性提出一种广义近似聚集支配算法,通过选取代表点代替近似集进行Skyline计算,减少冗余运算并优化查询结果,最终得到满足兴趣点近似整合有序的Skyline结果集。实验结果表明:所提近似查询算法在大规模数据集和大量相似数据条件下表现出较好的效率与可行性;与Higher-Gsky、MG-EGsky和GSSK-A算法相比,所提算法在数据规模、查询范围及路段数增加时的平均效率提升约14%,能够为道路网用户提供更快速有效的决策支持。 展开更多
关键词 道路网 SKYLINE查询 多目标决策 近似查询 兴趣点推荐
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基于多工况多目标的前副车架轻量化研究 被引量:2
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作者 薛文帅 王天波 +2 位作者 魏民祥 吴江 罗肇艺 《机械设计与研究》 北大核心 2025年第2期139-144,162,共7页
副车架作为汽车的重要组成部分,直接影响整车性能。由于汽车实际运行工况复杂,为避免研究工况单一性,同时考虑强度、模态等性能要求,结合多工况拓扑优化和多目标优化方法开展副车架轻量化设计。为准确分析典型工况下副车架受载情况,建... 副车架作为汽车的重要组成部分,直接影响整车性能。由于汽车实际运行工况复杂,为避免研究工况单一性,同时考虑强度、模态等性能要求,结合多工况拓扑优化和多目标优化方法开展副车架轻量化设计。为准确分析典型工况下副车架受载情况,建立前悬架刚柔耦合多体动力学模型,对原副车架进行动态和静态性能分析确定优化余量。定义典型工况的优化权重系数,结合折衷规划法构建多工况拓扑优化数学模型。针对传统副车架的结构优化往往依赖于工程师经验问题,采用变密度方法进行多工况拓扑优化,随后基于优化结果中的材料分布路径设计副车架参数模型。通过试验设计采集样本点,构建响应面近似模型(RSM)。采用邻域培植算法(NCGA)对副车架参数模型进行优化,设计变量为梁厚度,目标为最小质量和最大一阶频率,约束为一阶频率下限和应力值上限。结果表明:优化后的前副车架在保证结构性能的前提下,一阶非刚体模态提升3 Hz,重量降低了3.21 kg,轻量化率达11.7%,为其他相关产品结构设计提供参考。 展开更多
关键词 多工况多目标拓扑优化 前副车架 试验设计 响应面近似模型
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MFF-YOLO:An Improved YOLO Algorithm Based on Multi-Scale Semantic Feature Fusion 被引量:1
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作者 Junsan Zhang Chenyang Xu +2 位作者 Shigen Shen Jie Zhu Peiying Zhang 《Tsinghua Science and Technology》 2025年第5期2097-2113,共17页
The YOLOv5 algorithm is widely used in edge computing systems for object detection.However,the limited computing resources of embedded devices and the large model size of existing deep learning based methods increase ... The YOLOv5 algorithm is widely used in edge computing systems for object detection.However,the limited computing resources of embedded devices and the large model size of existing deep learning based methods increase the difficulty of real-time object detection on edge devices.To address this issue,we propose a smaller,less computationally intensive,and more accurate algorithm for object detection.Multi-scale Feature Fusion-YOLO(MFF-YOLO)is built on top of the YOLOv5s framework,but it contains substantial improvements to YOLOv5s.First,we design the MFF module to improve the feature propagation path in the feature pyramid,which further integrates the semantic information from different paths of feature layers.Then,a large convolution-kernel module is used in the bottleneck.The structure enlarges the receptive field and preserves shallow semantic information,which overcomes the performance limitation arising from uneven propagation in Feature Pyramid Networks(FPN).In addition,a multi-branch downsampling method based on depthwise separable convolutions and a bottleneck structure with deformable convolutions are designed to reduce the complexity of the backbone network and minimize the real-time performance loss caused by the increased model complexity.The experimental results on PASCAL VOC and MS COCO datasets show that,compared with YOLOv5s,MFF-YOLO reduces the number of parameters by 7%and the number of FLoating point Operations Per second(FLOPs)by 11.8%.The mAP@0.5 has improved by 3.7%and 5.5%,and the mAP@0.5:0.95 has improved by 6.5%and 6.2%,respetively.Furthermore,compared with YOLOv7-tiny,PP-YOLO-tiny,and other mainstream methods,MFF-YOLO has achieved better results on multiple indicators. 展开更多
关键词 object detection YOLOv5 Feature Pyramid Networks(FPN) feature fusion Deformable Convolutional Networks(DCN) multi-scale Feature Fusion(MFF)
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考虑可靠性的电驱动桥桥壳轻量化设计 被引量:1
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作者 李冬琦 高志彬 《机械传动》 北大核心 2025年第10期53-61,共9页
【目的】为解决电驱动桥桥壳的轻量化问题,提出一种基于近似模型和组合优化算法的轻量化设计方法,并引入6σ可靠性优化理论,以提升桥壳的稳定性。【方法】首先,通过灵敏度分析,选取对桥壳性能影响较大的结构参数作为设计变量;其次,根据... 【目的】为解决电驱动桥桥壳的轻量化问题,提出一种基于近似模型和组合优化算法的轻量化设计方法,并引入6σ可靠性优化理论,以提升桥壳的稳定性。【方法】首先,通过灵敏度分析,选取对桥壳性能影响较大的结构参数作为设计变量;其次,根据试验设计数据构建了桥壳的径向基函数(Radial Basis Function,RBF)神经网络近似模型,运用第二代非支配排序遗传算法(Non-dominated Sorting Genetic AlgorithmⅡ,NSGA-Ⅱ)和非线性序列二次规划(Non-Linear Programming by Quadratic Lagrangian,NLPQL)算法相结合的组合算法进行了确定性多目标优化;最后,考虑不确定性因素对桥壳性能的影响,引入6σ可靠性分析理论,基于RBF神经网络近似模型进行了桥壳的可靠性优化设计。【结果】结果表明,优化设计后,在桥壳性能变化不大的情况下,质量减轻6.9%;同时,桥壳各性能的可靠性提高,各参数均达到6σ水平。 展开更多
关键词 电驱动桥桥壳 轻量化设计 多目标优化 近似模型 组合算法
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变轨距机车悬挂参数多目标优化研究
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作者 邢晓曦 徐彬倢 +2 位作者 冉祥瑞 张洪军 王开云 《铁道机车车辆》 北大核心 2025年第3期88-95,共8页
合理优化悬挂参数以提高变轨距机车的动力学性能,建立变轨距机车动力学仿真模型,分析其在不同轨距下的直线运行平稳性和曲线通过性能,基于Simpack-Isight联合仿真平台构建变轨距机车近似模型,并采用NSGA-Ⅱ算法对转向架9个悬挂参数进行... 合理优化悬挂参数以提高变轨距机车的动力学性能,建立变轨距机车动力学仿真模型,分析其在不同轨距下的直线运行平稳性和曲线通过性能,基于Simpack-Isight联合仿真平台构建变轨距机车近似模型,并采用NSGA-Ⅱ算法对转向架9个悬挂参数进行多目标寻优计算。结果表明:变轨距车辆在1520 mm轨距上运行的动力学性能整体要劣于1435 mm轨距条件下的性能;经参数优化后变轨距机车动力学性能得到明显改善,其中横向平稳性指标优化效果最显著,优化率为15.27%。 展开更多
关键词 变轨距机车 悬挂参数 最优拉丁超立方 近似模型 多目标优化
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