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Twinning in Intermetallic Compounds Are Long Shear Vectors and/or Shuffles Really Necessary? 被引量:4
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作者 F.M.Chu David P.Pope Dept.of Materials Science and Engineering,University of Pennsylvania,Philadelphia,PA 19104,USA 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1993年第5期313-321,共9页
In this paper the geometric description and general theory of mechanical twinning are reviewed, the twins in general lattices and superlattices are summarized, and the kinetic process by which mechanical twins form is... In this paper the geometric description and general theory of mechanical twinning are reviewed, the twins in general lattices and superlattices are summarized, and the kinetic process by which mechanical twins form is revisited. A case study of mechanical twinning of HfV2+Nb, (cubic) Laves phase, is presented and the synchroshear of selected atomic layers is proposed to explain the physical process of twin formation. If the twins form in this way, then long shear vectors and / or atomicshuffles are not really necessary. 展开更多
关键词 TWIN intermetallic compounds shear vector shuffles
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Structured Shuffles and the Josephus Problem
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作者 Shaun Sullivan Thomas Beatty 《Open Journal of Discrete Mathematics》 2012年第4期138-141,共4页
The Australian Shuffle consists of placing a deck of cards onto a table according to this rule: put the top card on the table, the next card on the bottom of the deck, and repeat until all the cards have been placed o... The Australian Shuffle consists of placing a deck of cards onto a table according to this rule: put the top card on the table, the next card on the bottom of the deck, and repeat until all the cards have been placed on the table. A natural question is “Where was the very last card placed located in the original deck?” Card trick magicians have known empirically for years that the fortieth card from the top of a standard fifty-two card deck is the final card placed by this shuffle. The moniker “Australian” comes from putting every other card “Down Under”. We develop a formula for the general case of N cards, and then extend that generalization further to cases involving the discard of k cards before or after putting one on the bottom of the deck. Finally, we discuss the connection of the Australian Shuffle and its generalizations to the famous Josephus problem. 展开更多
关键词 JOSEPHUS SHUFFLING
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Multilevel Military Image Encryption Based on Tri-Independent Keying Approach
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作者 Shereen S.Jumaa Mohsin H.Challoob Amjad J.Humaidi 《Computers, Materials & Continua》 2026年第4期1548-1564,共17页
Military image encryption plays a vital role in ensuring the secure transmission of sensitive visual information from unauthorized access.This paper proposes a new Tri-independent keying method for encrypting military... Military image encryption plays a vital role in ensuring the secure transmission of sensitive visual information from unauthorized access.This paper proposes a new Tri-independent keying method for encrypting military images.The proposed encryption method is based on multilevel security stages of pixel-level scrambling,bitlevel manipulation,and block-level shuffling operations.For having a vast key space,the input password is hashed by the Secure Hash Algorithm 256-bit(SHA-256)for generating independently deterministic keys used in the multilevel stages.A piecewise pixel-level scrambling function is introduced to perform a dual flipping process controlled with an adaptive key for obscuring the spatial relationships between the adjacent pixels.Adynamicmasking scheme is presented for conducting a bit-level manipulation based on distinct keys that change over image regions,providing completely different encryption results on identical regions.To handle the global correlation between large-scale patterns,a chaotic index-map system is employed for shuffling image regions randomly across the image domain based on a logistic map seeded with a private key.Experimental results on a dataset of military images show the effectiveness of the proposed encryption method in producing excellent quantitative and qualitative results.The proposed method obtains uniform histogram distributions,high entropy values around the ideal(≈8 bits),Number of Pixel Change Rate(NPCR)values above 99.5%,and low Peak Signal-to-Noise Ratio(PSNR)over all encrypted images.This validates the robustness of the proposed method against cryptanalytic attacks,verifying its ability to serve as a practical basis for secure image transmission in defense systems. 展开更多
关键词 Military image encryption pixel-level scrambling bit-level manipulation block-level shuffling password hashing dynamic encryption key spatial pixel correlation chaotic system
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Speech Emotion Recognition Based on the Adaptive Acoustic Enhancement and Refined Attention Mechanism
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作者 Jun Li Chunyan Liang +1 位作者 Zhiguo Liu Fengpei Ge 《Computers, Materials & Continua》 2026年第3期2015-2039,共25页
To enhance speech emotion recognition capability,this study constructs a speech emotion recognition model integrating the adaptive acoustic mixup(AAM)and improved coordinate and shuffle attention(ICASA)methods.The AAM... To enhance speech emotion recognition capability,this study constructs a speech emotion recognition model integrating the adaptive acoustic mixup(AAM)and improved coordinate and shuffle attention(ICASA)methods.The AAM method optimizes data augmentation by combining a sample selection strategy and dynamic interpolation coefficients,thus enabling information fusion of speech data with different emotions at the acoustic level.The ICASA method enhances feature extraction capability through dynamic fusion of the improved coordinate attention(ICA)and shuffle attention(SA)techniques.The ICA technique reduces computational overhead by employing depth-separable convolution and an h-swish activation function and captures long-range dependencies of multi-scale time-frequency features using the attention weights.The SA technique promotes feature interaction through channel shuffling,which helps the model learn richer and more discriminative emotional features.Experimental results demonstrate that,compared to the baseline model,the proposed model improves the weighted accuracy by 5.42%and 4.54%,and the unweighted accuracy by 3.37%and 3.85%on the IEMOCAP and RAVDESS datasets,respectively.These improvements were confirmed to be statistically significant by independent samples t-tests,further supporting the practical reliability and applicability of the proposed model in real-world emotion-aware speech systems. 展开更多
关键词 Speech emotion recognition adaptive acoustic mixup enhancement improved coordinate attention shuffle attention attention mechanism deep learning
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基于改进YOLOv8-Track的芝麻单株蒴果检测计数研究 被引量:1
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作者 李琛昊 王川 +5 位作者 李国强 赵巧丽 杨萍 王凯 常升龙 郑国清 《河南农业科学》 北大核心 2025年第4期155-166,共12页
单株蒴果数是芝麻产量构成的重要因素。为实现单株芝麻蒴果的准确检测计数,使用目标检测、多目标追踪等技术,动态追踪单株蒴果,有助于提高芝麻育种和栽培管理效率。针对芝麻蒴果小目标、生长密集、遮挡重叠等现象,以YOLOv8-Track为基准... 单株蒴果数是芝麻产量构成的重要因素。为实现单株芝麻蒴果的准确检测计数,使用目标检测、多目标追踪等技术,动态追踪单株蒴果,有助于提高芝麻育种和栽培管理效率。针对芝麻蒴果小目标、生长密集、遮挡重叠等现象,以YOLOv8-Track为基准模型,在特征融合网络中引入小目标检测头和Shuffle attention注意力机制,在模型后处理阶段引入MPDIOU损失函数,构建了SD-YOLOv8-Track模型。然后利用模型ByteTrack多目标追踪算法的ID计数方法,以芝麻单株旋转视频作为模型输入,追踪统计芝麻蒴果数。结果表明,以单幅图片为输入,SD-YOLOv8-Track模型检测蒴果的准确率、召回率、平均精度分别为92.25%、92.4%、92.58%,比原模型YOLOv8-Track分别提高5.94、6.6、6.31百分点。以单株旋转视频为输入,SD-YOLOv8-Track模型的多目标追踪准确率、多目标追踪精确率分别为89.42%、88.23%,比原模型分别提高4.23、4.60百分点。SD-YOLOv8-Track模型检测蒴果的平均计数准确率、漏检率、误检率分别为93.27%、3.85%、2.88%,平均计数准确率比原模型提高5.61百分点,漏检率和误检率比原模型分别降低3.84、1.77百分点。改进后的SD-YOLOv8-Track模型具有较好的芝麻单株蒴果检测性能,适用于芝麻单株蒴果的动态完整计数。 展开更多
关键词 芝麻蒴果 检测计数 多目标追踪 动态计数 Shuffle attention MPDIOU YOLOv8-Track
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基于改进YOLO v8的苹果叶部病害检测方法 被引量:1
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作者 曾林涛 马嘉昕 +1 位作者 丁羽 许晓东 《江苏农业科学》 北大核心 2025年第5期147-156,共10页
针对苹果叶部病害在自然环境下形态和颜色特征较为复杂、区分度较低等特点,提出一种高效的病害检测模型,为病害的预防与科学化治理提供准确的依据。基于YOLO v8算法,在主干网络(backbone)末端,加入注意力机制Shuffle Attention(SA),根... 针对苹果叶部病害在自然环境下形态和颜色特征较为复杂、区分度较低等特点,提出一种高效的病害检测模型,为病害的预防与科学化治理提供准确的依据。基于YOLO v8算法,在主干网络(backbone)末端,加入注意力机制Shuffle Attention(SA),根据样本分布特点进行数据增强,引入Mixup、Mosaic、Random等数据增强方法增加特征表达能力,在提高检测性能的同时,不显著增加计算复杂度;在neck末端,使C2f模块与可变形卷积神经网络模块(Deformable Conv V2)相结合,以提升复杂背景下的检测性能,从而提高检测准确度,有效提高模型性能;为克服CIoU损失函数的局限性,采用MPDIoU损失函数,解决CIoU在特定场景下的限制。结果表明,相较于原始YOLO v8算法,本研究算法的平均准确率提升3.5百分点,mAP@0.5∶0.95提升4.6百分点,精确率提升3.6百分点,说明改进的算法在苹果叶部病害检测方面取得有效成果。 展开更多
关键词 YOLO v8 苹果叶部病害 目标检测 Shuffle Attention C2f_DCNV2 MPDIoU
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改进YOLOv8的遥感图像飞机目标轻量化检测算法 被引量:2
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作者 王莹 张上 +2 位作者 胡益民 王恒涛 院永莹 《遥感信息》 北大核心 2025年第1期134-141,共8页
针对遥感飞机目标检测存在模型体积和计算量较大的问题,提出一种基于YOLOv8的轻量化遥感飞机目标检测算法。首先,在主干网络中引入一种融合SRU和CRU的C2f_ScConv模块,通过空间重建和通道重建来减少中间特征映射冗余,并增强飞机目标特征... 针对遥感飞机目标检测存在模型体积和计算量较大的问题,提出一种基于YOLOv8的轻量化遥感飞机目标检测算法。首先,在主干网络中引入一种融合SRU和CRU的C2f_ScConv模块,通过空间重建和通道重建来减少中间特征映射冗余,并增强飞机目标特征表示,在保证精度的同时实现模型轻量化。然后,在头部网络中融入轻量型注意力机制shuffle attention,利用shuffle unit捕捉通道和空间维度的特征依赖,利用channel shuffle算子实现不同子特征之间的信息交流,进而提高飞机目标检测精度。最后,使用Inner-CIoU作为损失函数,加速样本收敛。实验表明,改进算法相较于YOLOv5s、YOLOv7-Tiny、YOLOv8n模型,体积降低57.2%、52.4%、7.9%,计算量降低53.4%、43.6%、7.4%,在保持较高模型检测精度的同时大幅降低了模型的复杂度,达到了轻量化的要求。 展开更多
关键词 飞机目标 YOLOv8 轻量化 C2f_ScConv shuffle attention Inner-IoU
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融合LBP与并行注意力机制的微表情识别方法
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作者 李帅超 李明泽 +1 位作者 孙嘉傲 卢树华 《北京航空航天大学学报》 北大核心 2025年第4期1404-1414,共11页
针对面部微表情变化强度弱、背景噪声干扰及特征区分度较小等问题,提出了一种融合LBP与并行注意力机制的微表情识别网络。该网络将RGB图像输入密集连接改进的Shuffle Stage分支提取面部全局特征,增强上下文语义信息关联;将LBP图像输入... 针对面部微表情变化强度弱、背景噪声干扰及特征区分度较小等问题,提出了一种融合LBP与并行注意力机制的微表情识别网络。该网络将RGB图像输入密集连接改进的Shuffle Stage分支提取面部全局特征,增强上下文语义信息关联;将LBP图像输入多尺度分层卷积神经网络构成的局部纹理特征分支,提取细节信息;双分支特征提取后,在网络后端引入并行注意力机制提高特征融合能力,抑制背景干扰,专注微表情特征兴趣区域;所提方法在CASME、CASME II和SMIC等3个公开数据集上进行了测试,识别准确率分别达到了85.18%、74.53%和81.19%;实验结果表明,所提方法有效提高了微表情识别准确率,优于当前诸多先进方法。 展开更多
关键词 微表情识别 密集连接 Shuffle Stage分支 多尺度分层卷积 并行注意力机制
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β-葡萄糖苷酶Bgl3热稳定性有益突变的鉴定与结构基础分析
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作者 许本宏 蒋奕文 +5 位作者 罗敬时 杨向鹏 李广 袁珊 刘玉焕 曹立创 《食品与发酵工业》 北大核心 2025年第15期1-8,共8页
DNA shuffling是蛋白质定向进化的一种常用策略,其优点是可以快速积累多突变效果,但同时由于突变数较多,其中真正发挥作用的突变及其结构基础往往不清楚。β-葡萄糖苷酶是纤维素高效降解的限速酶,良好的热稳定性是影响其实际催化效率的... DNA shuffling是蛋白质定向进化的一种常用策略,其优点是可以快速积累多突变效果,但同时由于突变数较多,其中真正发挥作用的突变及其结构基础往往不清楚。β-葡萄糖苷酶是纤维素高效降解的限速酶,良好的热稳定性是影响其实际催化效率的关键因素。该研究以DNA shuffling策略产生的热稳定性β-葡萄糖苷酶突变体Bgl3-6511(含60个突变,T_(50)值比野生型提高4.6℃)为研究对象,通过序列比对、定点突变和热稳定性测定,对其中的有益突变进行鉴定。结果显示,6个单点突变Y50F、R52H、R56K、V65I、T67A和P143A分别将该酶的T_(50)值提高2.9、4.2、1.5、2.8、3.2、1.2℃。同时,鉴定到5个有害突变将该酶的T_(50)值降低1.0~3.4℃。将获得单点有益突变进行组合,获得T_(50)值提高13.4℃的M6(Y50F/R52H/R56K/V65I/T67A/P143A),说明DNA shuffling策略积累的有害突变确实损害了性能优化。结构分析和分子动力学模拟显示,有益突变主要是通过增强分子内氢键、π-π键和稳定二级结构发挥作用。该研究对Bgl3-6511中的单点有益突变进行鉴定,对其结构基础进行了分析,并获得了热稳定性更加优良的突变酶,相关信息可为其他酶的分子改造提供有益借鉴。 展开更多
关键词 Β-葡萄糖苷酶 热稳定性 DNA shuffling 有益突变 定点突变 结构分析
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基于Shuffle Attention相似目标检测——以SA-YOLOv7为例
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作者 任昱臻 樊中奎 +1 位作者 冯振营 朱梅 《现代信息科技》 2025年第11期106-113,共8页
YOLOv7在目标检测中取得了优异的效果,但对相似物体的检测仍存在误检率较高的问题,其主要原因是YOLOv7对细粒度特征的提取能力不足。为解决上述问题,该研究提出SA-YOLOv7目标检测网络,即在不改变ELAN(Extend Efficient Layer Aggregatio... YOLOv7在目标检测中取得了优异的效果,但对相似物体的检测仍存在误检率较高的问题,其主要原因是YOLOv7对细粒度特征的提取能力不足。为解决上述问题,该研究提出SA-YOLOv7目标检测网络,即在不改变ELAN(Extend Efficient Layer Aggregation Networks)整体结构的前提下,将注意力模块SA(Shuffle Attention)与之融合,形成SA-ELAN模块,以获取更多通道和空间特征信息,进而提高相似物体的检测精确度。模型在公共的手和手套相似物体数据集上开展了大量对比实验,探究了SA加入YOLOv7网络中的数量及位置对结果的影响,揭示了SA发挥作用的底层原理,深化了对注意力机制的理解。实验结果显示:SA-YOLOv7相较于YOLOv7,检测精度提升了7.7%,mAP@0.5:0.95提高了1.8%,与最新的YOLOv11相比,也具有0.9%的检测精度优势。SA-YOLOv7的研究为相似物体检测技术的发展提供了助力。 展开更多
关键词 深度学习 YOLOv7 Shuffle Attention 相似目标检测
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TSMS-InceptionNeXt:A Framework for Image-Based Combustion State Recognition in Counterflow Burners via Feature Extraction Optimization
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作者 Huiling Yu Xibei Jia +1 位作者 Yongfeng Niu Yizhuo Zhang 《Computers, Materials & Continua》 2025年第6期4329-4352,共24页
The counterflow burner is a combustion device used for research on combustion.By utilizing deep convolutional models to identify the combustion state of a counter flow burner through visible flame images,it facilitate... The counterflow burner is a combustion device used for research on combustion.By utilizing deep convolutional models to identify the combustion state of a counter flow burner through visible flame images,it facilitates the optimization of the combustion process and enhances combustion efficiency.Among existing deep convolutional models,InceptionNeXt is a deep learning architecture that integrates the ideas of the Inception series and ConvNeXt.It has garnered significant attention for its computational efficiency,remarkable model accuracy,and exceptional feature extraction capabilities.However,since this model still has limitations in the combustion state recognition task,we propose a Triple-Scale Multi-Stage InceptionNeXt(TSMS-InceptionNeXt)combustion state recognitionmethod based on feature extraction optimization.First,to address the InceptionNeXt model’s limited ability to capture dynamic features in flame images,we introduce Triplet Attention,which applies attention to the width,height,and Red Green Blue(RGB)dimensions of the flame images to enhance its ability to model dynamic features.Secondly,to address the issue of key information loss in the Inception deep convolution layers,we propose a Similarity-based Feature Concentration(SimC)mechanism to enhance the model’s capability to concentrate on critical features.Next,to address the insufficient receptive field of the model,we propose a Multi-Scale Dilated Channel Parallel Integration(MDCPI)mechanism to enhance the model’s ability to extract multi-scale contextual information.Finally,to address the issue of the model’s Multi-Layer Perceptron Head(MlpHead)neglecting channel interactions,we propose a Channel Shuffle-Guided Channel-Spatial Attention(ShuffleCS)mechanism,which integrates information from different channels to further enhance the representational power of the input features.To validate the effectiveness of the method,experiments are conducted on the counterflow burner flame visible light image dataset.The experimental results show that the TSMS-InceptionNeXt model achieved an accuracy of 85.71%on the dataset,improving by 2.38%over the baseline model and outperforming the baseline model’s performance.It achieved accuracy improvements of 10.47%,4.76%,11.19%,and 9.28%compared to the Reparameterized Visual Geometry Group(RepVGG),Squeeze-erunhanced Axial Transoformer(SeaFormer),Simplified Graph Transformers(SGFormer),and VanillaNet models,respectively,effectively enhancing the recognition performance for combustion states in counterflow burners. 展开更多
关键词 Counterflow burner combustion state recognition InceptionNeXt dilated convolution channel shuffling
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融合多分组归并的券商数据Shuffle和数据倾斜算法
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作者 曹亚坤 唐小勇 《大数据》 2025年第6期123-142,共20页
在证券行业,用户数据处理和分析是核心技术,对业务决策和风险控制具有重要的影响。然而,证券公司庞大的用户数据规模和复杂的数据关系导致大数据计算面临Shuffle操作和数据倾斜问题。现有的Shuffle和数据倾斜优化方法或依赖于硬件升级,... 在证券行业,用户数据处理和分析是核心技术,对业务决策和风险控制具有重要的影响。然而,证券公司庞大的用户数据规模和复杂的数据关系导致大数据计算面临Shuffle操作和数据倾斜问题。现有的Shuffle和数据倾斜优化方法或依赖于硬件升级,或存在领域局限性,难以针对性解决该问题。为此,基于证券行业用户数据的特点,提出了一种基于用户关系的多分组归并算法(multi group merging algorithm,MGMA)。该算法通过有效分组和优化处理策略,显著提升计算效率,并降低计算资源消耗。实验表明,相较于无优化对照组,MGMA算法的数据倾斜率为20%,内存占用为72%,计算用时为61%,且上述3项指标均优于其他4种对比优化方法。 展开更多
关键词 Shuffle操作 数据倾斜 预处理 券商数据
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A Shufled Frog-Leaping Algorithm with Competition for Parallel Batch Processing Machines Scheduling in Fabric Dyeing Process
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作者 Mingbo Li Deming Lei 《Computer Modeling in Engineering & Sciences》 2025年第5期1789-1808,共20页
As a complicated optimization problem,parallel batch processing machines scheduling problem(PBPMSP)exists in many real-life manufacturing industries such as textiles and semiconductors.Machine eligibility means that a... As a complicated optimization problem,parallel batch processing machines scheduling problem(PBPMSP)exists in many real-life manufacturing industries such as textiles and semiconductors.Machine eligibility means that at least one machine is not eligible for at least one job.PBPMSP and scheduling problems with machine eligibility are frequently considered;however,PBPMSP with machine eligibility is seldom explored.This study investigates PBPMSP with machine eligibility in fabric dyeing and presents a novel shuffled frog-leaping algorithm with competition(CSFLA)to minimize makespan.In CSFLA,the initial population is produced in a heuristic and random way,and the competitive search of memeplexes comprises two phases.Competition between any two memeplexes is done in the first phase,then iteration times are adjusted based on competition,and search strategies are adjusted adaptively based on the evolution quality of memeplexes in the second phase.An adaptive population shuffling is given.Computational experiments are conducted on 100 instances.The computational results showed that the new strategies of CSFLA are effective and that CSFLA has promising advantages in solving the considered PBPMSP. 展开更多
关键词 Batch processing machines shuffled frog-leaping algorithm COMPETITION parallel machines scheduling
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Fast Attack Algorithm for JPEG Image Encryption with Block Position Shuffle
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作者 LI Shanshan GUO Yali +1 位作者 HUANG Jiaxin GAO Ruoyun 《Journal of Shanghai Jiaotong university(Science)》 2025年第5期976-987,共12页
For traditional JPEG image encryption,block position shuffling can achieve a better encryption effect and is resistant to non-zero counting attack.However,the numbers of non-zero coefficients in the 8×8 sub-block... For traditional JPEG image encryption,block position shuffling can achieve a better encryption effect and is resistant to non-zero counting attack.However,the numbers of non-zero coefficients in the 8×8 sub-blocks are unchanged using block position shuffle.For this defect,this paper proposes a fast attack algorithm for JPEG image encryption based on inter-block shuffle and non-zero quantization discrete cosine transformation coefficient attack.The algorithm analyzes the position mapping relationship before and after encryption of image blocks by detecting the pixel values of an image by the designed plaintext image.Then the preliminary attack result of the image blocks can be obtained from the inverse mapping relationship.Finally,the final attack result of the algorithm is generated according to the numbers of non-zero coefficients in each 8×8 block of the preliminary attack result.Every 8×8 block position is related with its number of non-zero discrete cosine transform coefficients in the designed plaintext.It is verified that the main content of the original image could be obtained without knowledge of the encryption algorithm and keys in a relatively short time. 展开更多
关键词 JPEG image inter-block shuffle discrete cosine transform coefficients non-zero coefficients fast attack
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An Adaptive Cooperated Shuffled Frog-Leaping Algorithm for Parallel Batch Processing Machines Scheduling in Fabric Dyeing Processes
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作者 Lianqiang Wu Deming Lei Yutong Cai 《Computers, Materials & Continua》 2025年第5期1771-1789,共19页
Fabric dyeing is a critical production process in the clothing industry and heavily relies on batch processing machines(BPM).In this study,the parallel BPM scheduling problem with machine eligibility in fabric dyeing ... Fabric dyeing is a critical production process in the clothing industry and heavily relies on batch processing machines(BPM).In this study,the parallel BPM scheduling problem with machine eligibility in fabric dyeing is considered,and an adaptive cooperated shuffled frog-leaping algorithm(ACSFLA)is proposed to minimize makespan and total tardiness simultaneously.ACSFLA determines the search times for each memeplex based on its quality,with more searches in high-quality memeplexes.An adaptive cooperated and diversified search mechanism is applied,dynamically adjusting search strategies for each memeplex based on their dominance relationships and quality.During the cooperated search,ACSFLA uses a segmented and dynamic targeted search approach,while in non-cooperated scenarios,the search focuses on local search around superior solutions to improve efficiency.Furthermore,ACSFLA employs adaptive population division and partial population shuffling strategies.Through these strategies,memeplexes with low evolutionary potential are selected for reconstruction in the next generation,while thosewithhighevolutionarypotential are retained to continue their evolution.Toevaluate the performance of ACSFLA,comparative experiments were conducted using ACSFLA,SFLA,ASFLA,MOABC,and NSGA-CC in 90 instances.The computational results reveal that ACSFLA outperforms the other algorithms in 78 of the 90 test cases,highlighting its advantages in solving the parallel BPM scheduling problem with machine eligibility. 展开更多
关键词 Batch processing machine parallel machine scheduling shuffled frog-leaping algorithm fabric dyeing process machine eligibility
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基于改进YOLOv3的金属表面缺陷检测 被引量:15
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作者 刘浩翰 孙铖 +1 位作者 贺怀清 惠康华 《计算机工程与科学》 CSCD 北大核心 2023年第7期1226-1235,共10页
为提高工业零件表面缺陷的检测效率,提出一种基于改进YOLOv3的目标检测方法。引入目前最新的具有通道置换的注意力机制SA,将其与YOLOv3模型骨架结构Darknet-53的残差单元进行组合改进构成SA残差块结构,充分利用特征通道信息,得到YOLOv3... 为提高工业零件表面缺陷的检测效率,提出一种基于改进YOLOv3的目标检测方法。引入目前最新的具有通道置换的注意力机制SA,将其与YOLOv3模型骨架结构Darknet-53的残差单元进行组合改进构成SA残差块结构,充分利用特征通道信息,得到YOLOv3-SA模型。针对不同数据集,对输入图像进行不同规模比例缩放,分别使用K-means方法对真实标框进行聚类以提高检测效率。实验结果表明,YOLOv3-SA模型查全率达95.4%,相比YOLOv3,mAP最多可提高约7%。 展开更多
关键词 深度学习 目标检测 YOLO SHUFFLE SA 注意力机制 K-MEANS
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基于内存与文件共享机制的Spark I/O性能优化 被引量:8
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作者 黄廷辉 王玉良 +1 位作者 汪振 崔更申 《计算机工程》 CAS CSCD 北大核心 2017年第3期1-6,共6页
通过对Spark采用的弹性分布式数据集及任务调度等关键技术进行分析,发现数据处理I/O时间是影响Spark计算性能的主要瓶颈。为此,研究Spark合并文件运行模式,该模式能够减少缓存文件数量,提高Spark的I/O效率,但存在内存开销较高的缺点。... 通过对Spark采用的弹性分布式数据集及任务调度等关键技术进行分析,发现数据处理I/O时间是影响Spark计算性能的主要瓶颈。为此,研究Spark合并文件运行模式,该模式能够减少缓存文件数量,提高Spark的I/O效率,但存在内存开销较高的缺点。在此基础上,给出改进的Spark Shuffle过程,即通过设计一种使每个Mapper只生成一个缓存文件的运行模式,并且每个Mapper共享同一个内存缓冲区,从而提高I/O效率和减少内存开销。仿真结果表明,与Spark默认模式相比,该运行模式宽依赖计算过程的I/O时间缩短42.9%,可有效提高内存利用率和Spark平台运算效率。 展开更多
关键词 分布式计算 Spark平台 Shuffle过程 磁盘I/O 任务调度
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基于双重小波系数集的音频水印算法研究 被引量:19
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作者 何泉 苏广川 《北京理工大学学报》 EI CAS CSCD 北大核心 2004年第2期170-173,共4页
提出一种基于双重小波系数集的音频水印算法,定义了双重小波系数集.对原始音频信号进行小波分解后,根据双重小波系数集内两个元素间的相互关系,对双重小波系数集进行选择并将其分成两类从而嵌入和提取水印.同时利用shuffle算法对水印序... 提出一种基于双重小波系数集的音频水印算法,定义了双重小波系数集.对原始音频信号进行小波分解后,根据双重小波系数集内两个元素间的相互关系,对双重小波系数集进行选择并将其分成两类从而嵌入和提取水印.同时利用shuffle算法对水印序列进行置乱,以提高系统的安全性.实验结果表明,该算法对原音频信号影响极小,并对于各种音频操作和攻击,如重采样、重量化、低通滤波、Mpeg编码、Gaussian噪声等具有较好的鲁棒性. 展开更多
关键词 双重小波系数集 数字水印 shuffle算法
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PCR技术的新进展 被引量:8
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作者 赵琦 李宾 周慧 《生命的化学》 CAS CSCD 2002年第3期288-289,共2页
PCR是用于在体外快速酶促扩增特定DNA片段的技术,本文对PCR技术的一些新方法进行了简要综述,包括易错PCR、DNA shuffilng、原位PCR、电子PCR、固相PCR和PCR芯片。
关键词 易错PCR DNA SHUFFLING 原位PCR 电子PCR 固相PCR PCR芯片
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基于SAW-YOLO v8n的葡萄幼果轻量化检测方法 被引量:7
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作者 张传栋 高鹏 +1 位作者 亓璐 丁华立 《农业机械学报》 EI CAS CSCD 北大核心 2024年第10期286-294,共9页
葡萄簇幼果果实受背景色、遮挡和光照变化的影响,检测难度大。为了实现对背景色、遮挡和光照变化具有鲁棒性的葡萄簇幼果检测,提出了一种融合随机注意力机制(Shuffle attention,SA)的改进YOLO v8n模型(SAW-YOLO v8n)。通过在YOLO v8n模... 葡萄簇幼果果实受背景色、遮挡和光照变化的影响,检测难度大。为了实现对背景色、遮挡和光照变化具有鲁棒性的葡萄簇幼果检测,提出了一种融合随机注意力机制(Shuffle attention,SA)的改进YOLO v8n模型(SAW-YOLO v8n)。通过在YOLO v8n模型的Neck结构中融入SA机制,增强网络多尺度特征融合能力,提升检测目标的特征信息表示,并抑制其他无关信息,提高检测网络检测精度,在不明显增加网络深度和内存开销的情况下,实现了葡萄簇幼果的高效准确检测;采用基于动态非单调聚焦机制的损失(Wise intersection over union loss,Wise-IoU Loss)作为边界框回归损失函数,加速网络收敛并进一步提高模型的准确率。构建了葡萄簇幼果的数据集GGrape,该数据集由3780幅复杂场景下的葡萄簇幼果图像及对应标注文件组成。通过该数据集对SAW-YOLO v8n模型进行训练和测试。测试结果表明,基于SAW-YOLO v8n的葡萄簇幼果检测算法的精度(Precision,P)、召回率(Recall,R)、平均精度均值(Mean average precision,mAP)和F1值分别为92.80%、91.30%、96.10%和92.04%,检测速度为140.85 f/s,模型内存占用量为6.20 MB。与SSD、YOLO v5s、YOLO v6n、YOLO v7-tiny、YOLO v8n等5个轻量化模型相比,其mAP值分别提高16.06%、1.05%、1.48%、0.84%、0.73%,F1值分别提高24.85%、1.43%、1.43%、1.09%、1.60%,模型内存占用量分别降低93.16%、56.94%、37.63%、47.00%、0,是所有模型中最小的,具有明显的轻量化、高精度优势。讨论了不同遮挡程度和光照条件的葡萄幼果检测,结果表明,基于SAW-YOLO v8n的葡萄幼果检测方法能适应不同遮挡和光照变化,具有良好的鲁棒性。结果表明,SAW-YOLO v8n不仅能满足对葡萄簇幼果检测的高精度、高速度、轻量化的要求,且具有较强的鲁棒性和实时性。 展开更多
关键词 葡萄幼果 疏果 目标检测 shuffle attention YOLO v8n Wise-IoU Loss
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