针对非侵入式负荷分解方法负荷特征捕捉不足、负荷分解精度不够等问题,文章提出一种基于改进BERT(bidirectional encoder representations from transformers)模型的多头自注意力非侵入式负荷分解方法(frequency and temporal attention...针对非侵入式负荷分解方法负荷特征捕捉不足、负荷分解精度不够等问题,文章提出一种基于改进BERT(bidirectional encoder representations from transformers)模型的多头自注意力非侵入式负荷分解方法(frequency and temporal attention-BERT, FAT-BERT)。首先通过傅里叶变换将时域数据转换为频域数据,采用多尺度卷积全面捕捉负荷信号的时域和频域特征,从而增强模型对多样化负荷信号的表达能力;其次,在多头自注意力机制中引入频率注意力机制,从而增强模型对时序数据中频率成分的感知能力,进一步改善复杂负荷模式的表示,改进BERT模型中增加局部自注意力从而减少不必要的全局计算,提升模型的运行速度;接着将残差连接和正则化技术结合使模型在训练过程中更加稳定,并且能够更好地避免过拟合,最后在REDD和UK-DALE数据集上对提出的方法进行实验,实验结果验证了所提方法的有效性。展开更多
针对“卡脖子”技术研究存在替代技术识别机制缺失与技术要素解析精度不足等局限,文章提出融合提示工程与BERT-LSTM模型的“卡脖子”替代技术识别方法。首先,基于商业管制清单(Commercial Control List,CCL)对ECCN物项进行解析,并开展...针对“卡脖子”技术研究存在替代技术识别机制缺失与技术要素解析精度不足等局限,文章提出融合提示工程与BERT-LSTM模型的“卡脖子”替代技术识别方法。首先,基于商业管制清单(Commercial Control List,CCL)对ECCN物项进行解析,并开展专利检索工作,通过SPC算法提取技术主路径的关键核心专利;其次,运用大语言模型提示工程抽取“问题-方案对”,借此解析技术功效,并结合功能导向搜索(Function-Oriented Search,FOS)初步查找可能具备技术替代功效的相关专利;再次,采用BERT-LSTM模型对专利文本实施二元分类,精准识别出具备技术替代功效的专利样本;通过提示工程抽取“方案-类别对”,系统识别替代技术方案;最后,建立科学-产业双维度评估体系完成替代技术潜力分级。文章以光刻技术为例,阐述该识别方法的应用流程,系统识别出极紫外(Extreme Ultra-violet,EUV)光刻技术的五种替代技术及其替代潜力。展开更多
方面级情感分析旨在识别文本中针对特定方面的情感倾向,然而现有研究仍面临多重挑战:基于BERT的方面级情感分析研究存在语义过拟合、低层级语义利用不足的问题;自注意力机制存在局部信息丢失的问题;多编码层和多粒度语义的结构存在信息...方面级情感分析旨在识别文本中针对特定方面的情感倾向,然而现有研究仍面临多重挑战:基于BERT的方面级情感分析研究存在语义过拟合、低层级语义利用不足的问题;自注意力机制存在局部信息丢失的问题;多编码层和多粒度语义的结构存在信息冗余问题。为此,提出一种融合BERT编码层的多粒度语义方面级情感分析模型(multi-granular semantic aspect-based sentiment analysis model with fusion of BERT encoding layers,MSBEL)。具体地,引入金字塔注意力机制,利用各个编码层的语义特征,并结合低层编码器以降低过拟合;通过多尺度门控卷积增强模型处理局部信息丢失的能力;使用余弦注意力突出与方面词相关的情感特征,从而减少信息冗余。t-SNE的可视化分析表明,MSBEL的情感表示聚类效果优于BERT。此外,在多个基准数据集上将本文模型与主流模型的性能进行了对比,结果显示:与LCF-BERT相比,本文模型在5个数据集上的F1分别提升了1.53%、3.94%、1.39%、6.68%、5.97%;与SenticGCN相比,本文模型的F1平均提升0.94%,最大提升2.12%;与ABSA-DeBERTa相比,本文模型的F1平均提升1.16%,最大提升4.20%,验证了本文模型在方面级情感分析任务上的有效性和优越性。展开更多
Single-atom catalysts(SACs)have garnered significant attention in lithium-sulfur(Li-S)batteries for their potential to mitigate the severe polysulfide shuttle effect and sluggish redox kinetics.However,the development...Single-atom catalysts(SACs)have garnered significant attention in lithium-sulfur(Li-S)batteries for their potential to mitigate the severe polysulfide shuttle effect and sluggish redox kinetics.However,the development of highly efficient SACs and a comprehensive understanding of their structure-activity relationships remain enormously challenging.Herein,a novel kind of Fe-based SAC featuring an asymmetric FeN_(5)-TeN_(4) coordination structure was precisely designed by introducing Te atom adjacent to the Fe active center to enhance the catalytic activity.Theoretical calculations reveal that the neighboring Te atom modulates the local coordination environment of the central Fe site,elevating the d-band center closer to the Fermi level and strengthening the d-p orbital hybridization between the catalyst and sulfur species,thereby immobilizing polysulfides and improving the bidirectional catalysis of Li-S redox.Consequently,the Fe-Te atom pair catalyst endows Li-S batteries with exceptional rate performance,achieving a high specific capacity of 735 mAh g^(−1) at 5 C,and remarkable cycling stability with a low decay rate of 0.038%per cycle over 1000 cycles at 1 C.This work provides fundamental insights into the electronic structure modulation of SACs and establishes a clear correlation between precisely engineered atomic configurations and their enhanced catalytic performance in Li-S electrochemistry.展开更多
Spam emails remain one of the most persistent threats to digital communication,necessitating effective detection solutions that safeguard both individuals and organisations.We propose a spam email classification frame...Spam emails remain one of the most persistent threats to digital communication,necessitating effective detection solutions that safeguard both individuals and organisations.We propose a spam email classification frame-work that uses Bidirectional Encoder Representations from Transformers(BERT)for contextual feature extraction and a multiple-window Convolutional Neural Network(CNN)for classification.To identify semantic nuances in email content,BERT embeddings are used,and CNN filters extract discriminative n-gram patterns at various levels of detail,enabling accurate spam identification.The proposed model outperformed Word2Vec-based baselines on a sample of 5728 labelled emails,achieving an accuracy of 98.69%,AUC of 0.9981,F1 Score of 0.9724,and MCC of 0.9639.With a medium kernel size of(6,9)and compact multi-window CNN architectures,it improves performance.Cross-validation illustrates stability and generalization across folds.By balancing high recall with minimal false positives,our method provides a reliable and scalable solution for current spam detection in advanced deep learning.By combining contextual embedding and a neural architecture,this study develops a security analysis method.展开更多
Recognizing human interactions in RGB videos is a critical task in computer vision,with applications in video surveillance.Existing deep learning-based architectures have achieved strong results,but are computationall...Recognizing human interactions in RGB videos is a critical task in computer vision,with applications in video surveillance.Existing deep learning-based architectures have achieved strong results,but are computationally intensive,sensitive to video resolution changes and often fail in crowded scenes.We propose a novel hybrid system that is computationally efficient,robust to degraded video quality and able to filter out irrelevant individuals,making it suitable for real-life use.The system leverages multi-modal handcrafted features for interaction representation and a deep learning classifier for capturing complex dependencies.Using Mask R-CNN and YOLO11-Pose,we extract grayscale silhouettes and keypoint coordinates of interacting individuals,while filtering out irrelevant individuals using a proposed algorithm.From these,we extract silhouette-based features(local ternary pattern and histogram of optical flow)and keypoint-based features(distances,angles and velocities)that capture distinct spatial and temporal information.A Bidirectional Long Short-Term Memory network(BiLSTM)then classifies the interactions.Extensive experiments on the UT Interaction,SBU Kinect Interaction and the ISR-UOL 3D social activity datasets demonstrate that our system achieves competitive accuracy.They also validate the effectiveness of the chosen features and classifier,along with the proposed system’s computational efficiency and robustness to occlusion.展开更多
Pipelines are extensively used in environments such as nuclear power plants,chemical factories,and medical devices to transport gases and liquids.These tubular environments often feature complex geometries,confined sp...Pipelines are extensively used in environments such as nuclear power plants,chemical factories,and medical devices to transport gases and liquids.These tubular environments often feature complex geometries,confined spaces,and millimeter-scale height restrictions,presenting significant challenges to conventional inspection methods.Here,we present an ultrasonic microrobot(weight,80 mg;dimensions,24 mm×7 mm;thickness,210μm)to realize agile and bidirectional navigation in narrow pipelines.The ultrathin structural design of the robot is achieved through a high-performance piezoelectric composite film microstructure based on MEMS technology.The robot exhibits various vibration modes when driven by ultrasonic frequency signals,its motion speed reaches81 cm s-1 at 54.8 k Hz,exceeding that of the fastest piezoelectric microrobots,and its forward and backward motion direction is controllable through frequency modulation,while the minimum driving voltage for initial movement can be as low as 3 VP-P.Additionally,the robot can effortlessly climb slopes up to 24.25°and carry loads more than 36 times its weight.The robot is capable of agile navigation through curved L-shaped pipes,pipes made of various materials(acrylic,stainless steel,and polyvinyl chloride),and even over water.To further demonstrate its inspection capabilities,a micro-endoscope camera is integrated into the robot,enabling real-time image capture inside glass pipes.展开更多
文摘针对非侵入式负荷分解方法负荷特征捕捉不足、负荷分解精度不够等问题,文章提出一种基于改进BERT(bidirectional encoder representations from transformers)模型的多头自注意力非侵入式负荷分解方法(frequency and temporal attention-BERT, FAT-BERT)。首先通过傅里叶变换将时域数据转换为频域数据,采用多尺度卷积全面捕捉负荷信号的时域和频域特征,从而增强模型对多样化负荷信号的表达能力;其次,在多头自注意力机制中引入频率注意力机制,从而增强模型对时序数据中频率成分的感知能力,进一步改善复杂负荷模式的表示,改进BERT模型中增加局部自注意力从而减少不必要的全局计算,提升模型的运行速度;接着将残差连接和正则化技术结合使模型在训练过程中更加稳定,并且能够更好地避免过拟合,最后在REDD和UK-DALE数据集上对提出的方法进行实验,实验结果验证了所提方法的有效性。
文摘针对“卡脖子”技术研究存在替代技术识别机制缺失与技术要素解析精度不足等局限,文章提出融合提示工程与BERT-LSTM模型的“卡脖子”替代技术识别方法。首先,基于商业管制清单(Commercial Control List,CCL)对ECCN物项进行解析,并开展专利检索工作,通过SPC算法提取技术主路径的关键核心专利;其次,运用大语言模型提示工程抽取“问题-方案对”,借此解析技术功效,并结合功能导向搜索(Function-Oriented Search,FOS)初步查找可能具备技术替代功效的相关专利;再次,采用BERT-LSTM模型对专利文本实施二元分类,精准识别出具备技术替代功效的专利样本;通过提示工程抽取“方案-类别对”,系统识别替代技术方案;最后,建立科学-产业双维度评估体系完成替代技术潜力分级。文章以光刻技术为例,阐述该识别方法的应用流程,系统识别出极紫外(Extreme Ultra-violet,EUV)光刻技术的五种替代技术及其替代潜力。
文摘方面级情感分析旨在识别文本中针对特定方面的情感倾向,然而现有研究仍面临多重挑战:基于BERT的方面级情感分析研究存在语义过拟合、低层级语义利用不足的问题;自注意力机制存在局部信息丢失的问题;多编码层和多粒度语义的结构存在信息冗余问题。为此,提出一种融合BERT编码层的多粒度语义方面级情感分析模型(multi-granular semantic aspect-based sentiment analysis model with fusion of BERT encoding layers,MSBEL)。具体地,引入金字塔注意力机制,利用各个编码层的语义特征,并结合低层编码器以降低过拟合;通过多尺度门控卷积增强模型处理局部信息丢失的能力;使用余弦注意力突出与方面词相关的情感特征,从而减少信息冗余。t-SNE的可视化分析表明,MSBEL的情感表示聚类效果优于BERT。此外,在多个基准数据集上将本文模型与主流模型的性能进行了对比,结果显示:与LCF-BERT相比,本文模型在5个数据集上的F1分别提升了1.53%、3.94%、1.39%、6.68%、5.97%;与SenticGCN相比,本文模型的F1平均提升0.94%,最大提升2.12%;与ABSA-DeBERTa相比,本文模型的F1平均提升1.16%,最大提升4.20%,验证了本文模型在方面级情感分析任务上的有效性和优越性。
基金supported by the National Natural Science Foundation(52302284,22002086,22204096)Shanghai Sailing Program(23YF1412200)the Fundamental Research Funds for the Central Universities(22120240314).
文摘Single-atom catalysts(SACs)have garnered significant attention in lithium-sulfur(Li-S)batteries for their potential to mitigate the severe polysulfide shuttle effect and sluggish redox kinetics.However,the development of highly efficient SACs and a comprehensive understanding of their structure-activity relationships remain enormously challenging.Herein,a novel kind of Fe-based SAC featuring an asymmetric FeN_(5)-TeN_(4) coordination structure was precisely designed by introducing Te atom adjacent to the Fe active center to enhance the catalytic activity.Theoretical calculations reveal that the neighboring Te atom modulates the local coordination environment of the central Fe site,elevating the d-band center closer to the Fermi level and strengthening the d-p orbital hybridization between the catalyst and sulfur species,thereby immobilizing polysulfides and improving the bidirectional catalysis of Li-S redox.Consequently,the Fe-Te atom pair catalyst endows Li-S batteries with exceptional rate performance,achieving a high specific capacity of 735 mAh g^(−1) at 5 C,and remarkable cycling stability with a low decay rate of 0.038%per cycle over 1000 cycles at 1 C.This work provides fundamental insights into the electronic structure modulation of SACs and establishes a clear correlation between precisely engineered atomic configurations and their enhanced catalytic performance in Li-S electrochemistry.
基金funded by Princess Nourah bint Abdulrahman University Researchers Supporting Project number(PNURSP2026R234)Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘Spam emails remain one of the most persistent threats to digital communication,necessitating effective detection solutions that safeguard both individuals and organisations.We propose a spam email classification frame-work that uses Bidirectional Encoder Representations from Transformers(BERT)for contextual feature extraction and a multiple-window Convolutional Neural Network(CNN)for classification.To identify semantic nuances in email content,BERT embeddings are used,and CNN filters extract discriminative n-gram patterns at various levels of detail,enabling accurate spam identification.The proposed model outperformed Word2Vec-based baselines on a sample of 5728 labelled emails,achieving an accuracy of 98.69%,AUC of 0.9981,F1 Score of 0.9724,and MCC of 0.9639.With a medium kernel size of(6,9)and compact multi-window CNN architectures,it improves performance.Cross-validation illustrates stability and generalization across folds.By balancing high recall with minimal false positives,our method provides a reliable and scalable solution for current spam detection in advanced deep learning.By combining contextual embedding and a neural architecture,this study develops a security analysis method.
基金supported and funded by Princess Nourah bint Abdulrahman University Researchers Supporting Project number(PNURSP2025R410),Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘Recognizing human interactions in RGB videos is a critical task in computer vision,with applications in video surveillance.Existing deep learning-based architectures have achieved strong results,but are computationally intensive,sensitive to video resolution changes and often fail in crowded scenes.We propose a novel hybrid system that is computationally efficient,robust to degraded video quality and able to filter out irrelevant individuals,making it suitable for real-life use.The system leverages multi-modal handcrafted features for interaction representation and a deep learning classifier for capturing complex dependencies.Using Mask R-CNN and YOLO11-Pose,we extract grayscale silhouettes and keypoint coordinates of interacting individuals,while filtering out irrelevant individuals using a proposed algorithm.From these,we extract silhouette-based features(local ternary pattern and histogram of optical flow)and keypoint-based features(distances,angles and velocities)that capture distinct spatial and temporal information.A Bidirectional Long Short-Term Memory network(BiLSTM)then classifies the interactions.Extensive experiments on the UT Interaction,SBU Kinect Interaction and the ISR-UOL 3D social activity datasets demonstrate that our system achieves competitive accuracy.They also validate the effectiveness of the chosen features and classifier,along with the proposed system’s computational efficiency and robustness to occlusion.
基金supported by the National Key Research and Development Program of China(No.2024YFB3212901)National Natural Science Foundation of China(12072189)the Medicine and Engineering Interdisciplinary Research Fund of Shanghai Jiao Tong University(No.YG2025ZD05)。
文摘Pipelines are extensively used in environments such as nuclear power plants,chemical factories,and medical devices to transport gases and liquids.These tubular environments often feature complex geometries,confined spaces,and millimeter-scale height restrictions,presenting significant challenges to conventional inspection methods.Here,we present an ultrasonic microrobot(weight,80 mg;dimensions,24 mm×7 mm;thickness,210μm)to realize agile and bidirectional navigation in narrow pipelines.The ultrathin structural design of the robot is achieved through a high-performance piezoelectric composite film microstructure based on MEMS technology.The robot exhibits various vibration modes when driven by ultrasonic frequency signals,its motion speed reaches81 cm s-1 at 54.8 k Hz,exceeding that of the fastest piezoelectric microrobots,and its forward and backward motion direction is controllable through frequency modulation,while the minimum driving voltage for initial movement can be as low as 3 VP-P.Additionally,the robot can effortlessly climb slopes up to 24.25°and carry loads more than 36 times its weight.The robot is capable of agile navigation through curved L-shaped pipes,pipes made of various materials(acrylic,stainless steel,and polyvinyl chloride),and even over water.To further demonstrate its inspection capabilities,a micro-endoscope camera is integrated into the robot,enabling real-time image capture inside glass pipes.
