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Information Hiding Method Based on Block DWT Sub-Band Feature Encoding
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作者 Qiudong SUN Wenxin MA +1 位作者 Wenying YAN Hong DAI 《Journal of Software Engineering and Applications》 2009年第5期383-387,共5页
For realizing of long text information hiding and covert communication, a binary watermark sequence was obtained firstly from a text file and encoded by a redundant encoding method. Then, two neighboring blocks were s... For realizing of long text information hiding and covert communication, a binary watermark sequence was obtained firstly from a text file and encoded by a redundant encoding method. Then, two neighboring blocks were selected at each time from the Hilbert scanning sequence of carrier image blocks, and transformed by 1-level discrete wavelet transformation (DWT). And then the double block based JNDs (just noticeable difference) were calculated with a visual model. According to the different codes of each two watermark bits, the average values of two corresponding detail sub-bands were modified by using one of JNDs to hide information into carrier image. The experimental results show that the hidden information is invisible to human eyes, and the algorithm is robust to some common image processing operations. The conclusion is that the algorithm is effective and practical. 展开更多
关键词 sub-band feature encoding REDUNDANT encoding Visual Model Discrete WAVELET TRANSFORMATION Information Hiding
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A Fine-Grained RecognitionModel based on Discriminative Region Localization and Efficient Second-Order Feature Encoding
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作者 Xiaorui Zhang Yingying Wang +3 位作者 Wei Sun Shiyu Zhou Haoming Zhang Pengpai Wang 《Computers, Materials & Continua》 2026年第4期946-965,共20页
Discriminative region localization and efficient feature encoding are crucial for fine-grained object recognition.However,existing data augmentation methods struggle to accurately locate discriminative regions in comp... Discriminative region localization and efficient feature encoding are crucial for fine-grained object recognition.However,existing data augmentation methods struggle to accurately locate discriminative regions in complex backgrounds,small target objects,and limited training data,leading to poor recognition.Fine-grained images exhibit“small inter-class differences,”and while second-order feature encoding enhances discrimination,it often requires dual Convolutional Neural Networks(CNN),increasing training time and complexity.This study proposes a model integrating discriminative region localization and efficient second-order feature encoding.By ranking feature map channels via a fully connected layer,it selects high-importance channels to generate an enhanced map,accurately locating discriminative regions.Cropping and erasing augmentations further refine recognition.To improve efficiency,a novel second-order feature encoding module generates an attention map from the fourth convolutional group of Residual Network 50 layers(ResNet-50)and multiplies it with features from the fifth group,producing second-order features while reducing dimensionality and training time.Experiments on Caltech-University of California,San Diego Birds-200-2011(CUB-200-2011),Stanford Car,and Fine-Grained Visual Classification of Aircraft(FGVC Aircraft)datasets show state-of-the-art accuracy of 88.9%,94.7%,and 93.3%,respectively. 展开更多
关键词 Fine-grained recognition feature encoding data augmentation second-order feature discriminative regions
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Joint Feature Encoding and Task Alignment Mechanism for Emotion-Cause Pair Extraction
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作者 Shi Li Didi Sun 《Computers, Materials & Continua》 SCIE EI 2025年第1期1069-1086,共18页
With the rapid expansion of social media,analyzing emotions and their causes in texts has gained significant importance.Emotion-cause pair extraction enables the identification of causal relationships between emotions... With the rapid expansion of social media,analyzing emotions and their causes in texts has gained significant importance.Emotion-cause pair extraction enables the identification of causal relationships between emotions and their triggers within a text,facilitating a deeper understanding of expressed sentiments and their underlying reasons.This comprehension is crucial for making informed strategic decisions in various business and societal contexts.However,recent research approaches employing multi-task learning frameworks for modeling often face challenges such as the inability to simultaneouslymodel extracted features and their interactions,or inconsistencies in label prediction between emotion-cause pair extraction and independent assistant tasks like emotion and cause extraction.To address these issues,this study proposes an emotion-cause pair extraction methodology that incorporates joint feature encoding and task alignment mechanisms.The model consists of two primary components:First,joint feature encoding simultaneously generates features for emotion-cause pairs and clauses,enhancing feature interactions between emotion clauses,cause clauses,and emotion-cause pairs.Second,the task alignment technique is applied to reduce the labeling distance between emotion-cause pair extraction and the two assistant tasks,capturing deep semantic information interactions among tasks.The proposed method is evaluated on a Chinese benchmark corpus using 10-fold cross-validation,assessing key performance metrics such as precision,recall,and F1 score.Experimental results demonstrate that the model achieves an F1 score of 76.05%,surpassing the state-of-the-art by 1.03%.The proposed model exhibits significant improvements in emotion-cause pair extraction(ECPE)and cause extraction(CE)compared to existing methods,validating its effectiveness.This research introduces a novel approach based on joint feature encoding and task alignment mechanisms,contributing to advancements in emotion-cause pair extraction.However,the study’s limitation lies in the data sources,potentially restricting the generalizability of the findings. 展开更多
关键词 Emotion-cause pair extraction interactive information enhancement joint feature encoding label consistency task alignment mechanisms
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Improve Fractal Compression Encoding Speed Using Feature Extraction and Self-organization Network 被引量:1
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作者 Berthe Kya, Yang Yang Information Engineering School. University of Science and Technology Beijing. Beijing 100083. China 《Journal of University of Science and Technology Beijing》 CSCD 2001年第4期306-310,共5页
Image compression consists of two main parts: encoding and decoding. One of the important problems of the fractal theory is the long encoding implementation time, which hindered the acceptance of fractal image compres... Image compression consists of two main parts: encoding and decoding. One of the important problems of the fractal theory is the long encoding implementation time, which hindered the acceptance of fractal image compression as a practical method. The long encoding time results from the need to perform a large number of domain-range matches, the total encoding time is the product of the number of matches and the time to perform each match. In order to improve encoding speed, a hybrid method combining features extraction and self-organization network has been provided, which is based on the feature extraction approach the comparison pixels by pixels between the feature of range blocks and domains blocks. The efficiency of the new method was been proved by examples. 展开更多
关键词 image compression fractal theory features extraction self-organization network fractal encoding
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Prediction of Pediatric Sepsis Using a Deep Encoding Network with Cross Features
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作者 陈潇 张瑞 +1 位作者 汤心溢 钱娟 《Journal of Shanghai Jiaotong university(Science)》 EI 2024年第1期131-140,共10页
Sepsis poses a serious threat to health of children in pediatric intensive care unit.The mortality from pediatric sepsis can be effectively reduced through in-time diagnosis and therapeutic intervention.The bacillicul... Sepsis poses a serious threat to health of children in pediatric intensive care unit.The mortality from pediatric sepsis can be effectively reduced through in-time diagnosis and therapeutic intervention.The bacilliculture detection method is too time-consuming to receive timely treatment.In this research,we propose a new framework:a deep encoding network with cross features(CF-DEN)that enables accurate early detection of sepsis.Cross features are automatically constructed via the gradient boosting decision tree and distilled into the deep encoding network(DEN)we designed.The DEN is aimed at learning sufficiently effective representation from clinical test data.Each layer of the DEN fltrates the features involved in computation at current layer via attention mechanism and outputs the current prediction which is additive layer by layer to obtain the embedding feature at last layer.The framework takes the advantage of tree-based method and neural network method to extract effective representation from small clinical dataset and obtain accurate prediction in order to prompt patient to get timely treatment.We evaluate the performance of the framework on the dataset collected from Shanghai Children's Medical Center.Compared with common machine learning methods,our method achieves the increase on F1-score by 16.06%on the test set. 展开更多
关键词 pediatric sepsis gradient boosting decision tree cross feature neural network deep encoding network with cross features(CF-DEN)
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Feature Enhanced Stacked Auto Encoder for Diseases Detection in Brain MRI 被引量:1
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作者 Umair Muneer Butt Rimsha Arif +2 位作者 Sukumar Letchmunan Babur Hayat Malik Muhammad Adil Butt 《Computers, Materials & Continua》 SCIE EI 2023年第8期2551-2570,共20页
The detection of brain disease is an essential issue in medical and research areas.Deep learning techniques have shown promising results in detecting and diagnosing brain diseases using magnetic resonance imaging(MRI)... The detection of brain disease is an essential issue in medical and research areas.Deep learning techniques have shown promising results in detecting and diagnosing brain diseases using magnetic resonance imaging(MRI)images.These techniques involve training neural networks on large datasets of MRI images,allowing the networks to learn patterns and features indicative of different brain diseases.However,several challenges and limitations still need to be addressed further to improve the accuracy and effectiveness of these techniques.This paper implements a Feature Enhanced Stacked Auto Encoder(FESAE)model to detect brain diseases.The standard stack auto encoder’s results are trivial and not robust enough to boost the system’s accuracy.Therefore,the standard Stack Auto Encoder(SAE)is replaced with a Stacked Feature Enhanced Auto Encoder with a feature enhancement function to efficiently and effectively get non-trivial features with less activation energy froman image.The proposed model consists of four stages.First,pre-processing is performed to remove noise,and the greyscale image is converted to Red,Green,and Blue(RGB)to enhance feature details for discriminative feature extraction.Second,feature Extraction is performed to extract significant features for classification using DiscreteWavelet Transform(DWT)and Channelization.Third,classification is performed to classify MRI images into four major classes:Normal,Tumor,Brain Stroke,and Alzheimer’s.Finally,the FESAE model outperforms the state-of-theart,machine learning,and deep learning methods such as Artificial Neural Network(ANN),SAE,Random Forest(RF),and Logistic Regression(LR)by achieving a high accuracy of 98.61% on a dataset of 2000 MRI images.The proposed model has significant potential for assisting radiologists in diagnosing brain diseases more accurately and improving patient outcomes. 展开更多
关键词 Brain diseases deep learning feature enhanced stacked auto encoder stack auto encoder
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Enhanced Multimodal Sentiment Analysis via Integrated Spatial Position Encoding and Fusion Embedding
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作者 Chenquan Gan Xu Liu +3 位作者 Yu Tang Xianrong Yu Qingyi Zhu Deepak Kumar Jain 《Computers, Materials & Continua》 2025年第12期5399-5421,共23页
Multimodal sentiment analysis aims to understand emotions from text,speech,and video data.However,current methods often overlook the dominant role of text and suffer from feature loss during integration.Given the vary... Multimodal sentiment analysis aims to understand emotions from text,speech,and video data.However,current methods often overlook the dominant role of text and suffer from feature loss during integration.Given the varying importance of each modality across different contexts,a central and pressing challenge in multimodal sentiment analysis lies in maximizing the use of rich intra-modal features while minimizing information loss during the fusion process.In response to these critical limitations,we propose a novel framework that integrates spatial position encoding and fusion embedding modules to address these issues.In our model,text is treated as the core modality,while speech and video features are selectively incorporated through a unique position-aware fusion process.The spatial position encoding strategy preserves the internal structural information of speech and visual modalities,enabling the model to capture localized intra-modal dependencies that are often overlooked.This design enhances the richness and discriminative power of the fused representation,enabling more accurate and context-aware sentiment prediction.Finally,we conduct comprehensive evaluations on two widely recognized standard datasets in the field—CMU-MOSI and CMU-MOSEI to validate the performance of the proposed model.The experimental results demonstrate that our model exhibits good performance and effectiveness for sentiment analysis tasks. 展开更多
关键词 Multimodal sentiment analysis spatial position encoding fusion embedding feature loss reduction
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A Lightweight Network with Dual Encoder and Cross Feature Fusion for Cement Pavement Crack Detection
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作者 Zhong Qu Guoqing Mu Bin Yuan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期255-273,共19页
Automatic crack detection of cement pavement chiefly benefits from the rapid development of deep learning,with convolutional neural networks(CNN)playing an important role in this field.However,as the performance of cr... Automatic crack detection of cement pavement chiefly benefits from the rapid development of deep learning,with convolutional neural networks(CNN)playing an important role in this field.However,as the performance of crack detection in cement pavement improves,the depth and width of the network structure are significantly increased,which necessitates more computing power and storage space.This limitation hampers the practical implementation of crack detection models on various platforms,particularly portable devices like small mobile devices.To solve these problems,we propose a dual-encoder-based network architecture that focuses on extracting more comprehensive fracture feature information and combines cross-fusion modules and coordinated attention mechanisms formore efficient feature fusion.Firstly,we use small channel convolution to construct shallow feature extractionmodule(SFEM)to extract low-level feature information of cracks in cement pavement images,in order to obtainmore information about cracks in the shallowfeatures of images.In addition,we construct large kernel atrous convolution(LKAC)to enhance crack information,which incorporates coordination attention mechanism for non-crack information filtering,and large kernel atrous convolution with different cores,using different receptive fields to extract more detailed edge and context information.Finally,the three-stage feature map outputs from the shallow feature extraction module is cross-fused with the two-stage feature map outputs from the large kernel atrous convolution module,and the shallow feature and detailed edge feature are fully fused to obtain the final crack prediction map.We evaluate our method on three public crack datasets:DeepCrack,CFD,and Crack500.Experimental results on theDeepCrack dataset demonstrate the effectiveness of our proposed method compared to state-of-the-art crack detection methods,which achieves Precision(P)87.2%,Recall(R)87.7%,and F-score(F1)87.4%.Thanks to our lightweight crack detectionmodel,the parameter count of the model in real-world detection scenarios has been significantly reduced to less than 2M.This advancement also facilitates technical support for portable scene detection. 展开更多
关键词 Shallow feature extraction module large kernel atrous convolution dual encoder lightweight network crack detection
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EFFECTIVE FEATURE ANALYSIS FOR COLOR IMAGE SEGMENTATION 被引量:2
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作者 黎宁 毛四新 李有福 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2001年第2期206-212,共7页
An approach for color image segmentation is proposed based on the contributions of color features to segmentation rather than the choice of a particular color space. The determination of effective color features depen... An approach for color image segmentation is proposed based on the contributions of color features to segmentation rather than the choice of a particular color space. The determination of effective color features depends on the analysis of various color features from each tested color image via the designed feature encoding. It is different from the pervious methods where self organized feature map (SOFM) is used for constructing the feature encoding so that the feature encoding can self organize the effective features for different color images. Fuzzy clustering is applied for the final segmentation when the well suited color features and the initial parameter are available. The proposed method has been applied in segmenting different types of color images and the experimental results show that it outperforms the classical clustering method. The study shows that the feature encoding approach offers great promise in automating and optimizing the segmentation of color images. 展开更多
关键词 image segmentation color image neural networks fuzzy clustering feature encoding
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Anti-noise sound recognition based on energy-frequency feature
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作者 ZHOU Xiaomin LI Ying 《智能系统学报》 CSCD 北大核心 2015年第5期810-819,共10页
In the natural environment,non-stationary background noise affects the animal sound recognition directly.Given this problem,a new technology of animal sound recognition based on energy-frequency(E-F)feature is propose... In the natural environment,non-stationary background noise affects the animal sound recognition directly.Given this problem,a new technology of animal sound recognition based on energy-frequency(E-F)feature is proposed in this paper.The animal sound is turned into spectrogram to show the energy,time and frequency characteristics.The sub-band frequency division and sub-band energy division are carried out on the spectrogram for extracting the statistical characteristic of energy and frequency,so as to achieve sub-band power distribution(SPD)and sub-band division.Radon transform(RT)and discrete wavelet transform(DWT)are employed to obtain the important projection coefficients,and the energy values of sub-band frequencies are calculated to extract the sub-band frequency feature.The E-F feature is formed by combining the SPD feature and sub-band energy value feature.The classification is achieved by support vector machine(SVM)classifier.The experimental results show that the method can achieve better recognition effect even when the SNR is below10 dB. 展开更多
关键词 animal sound recognition sub-band power distribution(SPD) sub-band FREQUENCY feature RADON transform(RT) energy-frequency(E-F)feature
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利用编码器-解码器的温室温湿度长序列预测
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作者 盖荣丽 王鹏飞 +1 位作者 郭志斌 段立明 《小型微型计算机系统》 北大核心 2026年第1期89-96,共8页
针对现有温湿度预测模型难以充分考虑温室温湿度数据本身的复杂非线性特征和长期依赖关系,导致模型在实际应用中预测精度不足问题,本文提出了一种基于编码器-解码器架构的多层结构温湿度预测模型.模型通过卷积运算对数据进行多尺度转换... 针对现有温湿度预测模型难以充分考虑温室温湿度数据本身的复杂非线性特征和长期依赖关系,导致模型在实际应用中预测精度不足问题,本文提出了一种基于编码器-解码器架构的多层结构温湿度预测模型.模型通过卷积运算对数据进行多尺度转换和特征提取,并使用改进的双向限制性耦合长短期记忆网络(Bidirectional Restrictive Coupled Long-Short Term Memory,BiRCLSTM)优化了信息传递机制,同时运用多头注意力机制从不同的表示子空间中捕捉信息,最终实现了长序列多变量温室温湿度数据的精确预测.在自建温湿度数据集中,该模型的预测误差明显优于基线模型,并且该模型还在3个公共数据集上进行了不同时间分辨率的预测实验,综合实验结果表明,本文模型在温室温湿度预测中具有更高的精度和良好的泛化性能. 展开更多
关键词 温湿度预测 长时间序列 多变量特征 编码器-解码器 长短期记忆网络
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基于线性注意和类别关联特征学习的在线动作检测
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作者 詹永照 孙慧敏 +1 位作者 夏惠芬 任晓鹏 《江苏大学学报(自然科学版)》 北大核心 2026年第1期39-47,63,共10页
为了在在线动作检测中充分合理利用动作的上下文特征、与类别关联的特征和预测的未来特征快速检测相应动作,提出基于线性注意和类别关联特征学习的在线动作检测方法.该方法改进了Transformer构架,采用哈达玛积的轻型线性自注意实现Trans... 为了在在线动作检测中充分合理利用动作的上下文特征、与类别关联的特征和预测的未来特征快速检测相应动作,提出基于线性注意和类别关联特征学习的在线动作检测方法.该方法改进了Transformer构架,采用哈达玛积的轻型线性自注意实现Transformer视频上下文特征学习,以减少计算开销;其次对训练样本动作特征进行聚类,将视频序列上下文特征与动作类别特征进行关联学习,有效获得与类别关联的特征表达;最后融合动作的上下文特征、与类别关联的特征和预测的未来特征检测相应时刻动作,以提升动作鉴别性.在典型数据集上进行性能试验,完成了超参取值分析,对比了不同方法的工作精度和运行效率.给出了消融试验和可视化分析.结果表明:在Thumos14(TSN-Anet)、Thumos14(TSN-Kinetics)和HDD数据集上,所提出方法的mAP比Colar方法分别提高了0.2、0.5、0.2百分点,可见新方法优于目前较先进的Colar方法. 展开更多
关键词 在线动作检测 深度学习 注意力机制 编码 上下文特征 TRANSFORMER 类别关联特征学习
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基于注意力和变分类自编码的PCB小样本缺陷检测
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作者 宋涛 冉璐 +4 位作者 杨金河 邢镔 龙邹荣 王泓俊 李梓谦 《计算机工程与应用》 北大核心 2026年第4期363-372,共10页
针对小样本印刷电路板(printed circuit board,PCB)缺陷样本少、样本失衡、难泛化导致检测精度较低的问题,引入元学习方案,在元学习目标检测框架上提出基于注意力和变分类自编码的小样本缺陷检测方法。针对支持分支建模易受噪声影响问题... 针对小样本印刷电路板(printed circuit board,PCB)缺陷样本少、样本失衡、难泛化导致检测精度较低的问题,引入元学习方案,在元学习目标检测框架上提出基于注意力和变分类自编码的小样本缺陷检测方法。针对支持分支建模易受噪声影响问题,提出基于注意力的背景弱化模块,通过对注意力机制进行改进,使模型能够自适应改变重要性,聚焦前景信息与周围差异,减少背景干扰。鉴于支持分支缺乏类特征提取,导致查询特征与支持特征聚合后容易发生漏检、错检的问题,提出变分类自编码模块,利用概率分布以及重参数化获得类特征,提高新类检测准确率。为了充分探索查询特征与支持特征高级特征关系,提出多特征聚合模块,利用元素乘法、减法运算对两种特征之间的相似点和差异性进行建模,同时通过查询原型减少随机采样带来的噪声。实验结果表明,在PKU-Market-PCB数据集上,该方法在10样本下新类、基类准确率最高可达到65.3%、89.7%。 展开更多
关键词 小样本目标检测 元学习 注意力机制 变分类自编码 多特征聚合
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基于参数自适应FMD和SDAE的变负载下轴承故障诊断
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作者 何勇 刘晓玲 《振动与冲击》 北大核心 2026年第2期189-200,共12页
针对堆叠降噪自编码器(stacked denoisingauto-encoder,SDAE)网络在强噪声干扰及变负载工况下难以准确识别滚动轴承故障特征这一难题,提出一种基于特征模态分解(feature mode decomposition,FMD)与SDAE相结合的滚动轴承故障诊断方法。首... 针对堆叠降噪自编码器(stacked denoisingauto-encoder,SDAE)网络在强噪声干扰及变负载工况下难以准确识别滚动轴承故障特征这一难题,提出一种基于特征模态分解(feature mode decomposition,FMD)与SDAE相结合的滚动轴承故障诊断方法。首先,采用信号自相关函数对传统基尼系数进行改进;其次,以改进基尼系数作为模态分量评价指标,建立了参数自适应FMD方法,并采用该方法对SDAE网络输入信号进行降噪;最后,将降噪后信号的包络谱输入到SDAE网络中并得到滚动轴承变负载工况下的故障类型诊断结果。基于3个开源数据集的算例分析表明,该方法能够有效提升SDAE网络的滚动轴承故障诊断准确率。通过与其他方法的对比,验证了该方法具有更好的稳定性和更高的故障诊断准确率。 展开更多
关键词 故障诊断 滚动轴承 堆叠降噪自编码器(SDAE) 参数自适应特征模态分解(FMD) 变负载工况
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基于多特征融合的修船结算编码智能匹配复合模型
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作者 朱安庆 朱碧玉 +1 位作者 姚飚 李同兰 《造船技术》 2026年第1期23-30,共8页
在一些修船企业建立的修船结算系统和电子价格库中,人工匹配结算编码步骤易出错且耗时长,直接影响结算效率。为解决该问题,提出一种基于多特征融合的修船结算编码智能匹配复合模型。采用来自变换器的双向编码器表示(Bidirectional Encod... 在一些修船企业建立的修船结算系统和电子价格库中,人工匹配结算编码步骤易出错且耗时长,直接影响结算效率。为解决该问题,提出一种基于多特征融合的修船结算编码智能匹配复合模型。采用来自变换器的双向编码器表示(Bidirectional Encoder Representations from Transformers,BERT)模型将工程内容文本表示为词向量,采用卷积神经网络(Convolutional Neural Network,CNN)模型提取文本的局部特征,采用双向长短期记忆网络结合注意力机制(Bidirectional Long Short-Term Memory with Attention Mechanism,BiLSTM-Attention)模型提取上下文特征,得到对应的结算编码。试验结果表明,所提出的复合模型在整体准确率方面实现显著提升,充分证明该复合模型在处理复杂文本分类任务中的优势。 展开更多
关键词 修船结算编码智能匹配复合模型 多特征融合 来自变换器的双向编码器表示模型 卷积神经网络模型 双向长短期记忆网络结合注意力机制模型
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基于机器学习的线谱特征提取方法
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作者 师俊杰 熊凌霜 孙大军 《船舶力学》 北大核心 2026年第1期159-167,共9页
针对人工提取线谱特征方法的不足,本文对线谱特征提取原理进行研究,提出一种基于机器学习的线谱特征提取方法。搭建基于卷积神经网络的编码器-解码器,并在卷积和池化层间引入注意力机制,使输入数据的重要特征占据更高的权重,从而提高特... 针对人工提取线谱特征方法的不足,本文对线谱特征提取原理进行研究,提出一种基于机器学习的线谱特征提取方法。搭建基于卷积神经网络的编码器-解码器,并在卷积和池化层间引入注意力机制,使输入数据的重要特征占据更高的权重,从而提高特征提取的准确度。将模型与U-Net模型和TPSW算法在低信噪比情况下进行比较,并在实际数据上进行测试。实验结果表明,在谱级信噪比为5 dB时,改进模型线定位精度可达到0.823,在0~5 dB时均优于U-Net模型和TPSW算法,达到了提取线谱有效信息,提高水下目标检测准确率的目的。 展开更多
关键词 线谱特征提取 机器学习 编码-解码器 水下目标检测
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基于时空特征融合的Encoder-Decoder多步4D短期航迹预测 被引量:3
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作者 石庆研 张泽中 韩萍 《信号处理》 CSCD 北大核心 2023年第11期2037-2048,共12页
航迹预测在确保空中交通安全、高效运行中扮演着至关重要的角色。所预测的航迹信息是航迹优化、冲突告警等决策工具的输入,而预测准确性取决于模型对航迹序列特征的提取能力。航迹序列数据是具有丰富时空特征的多维时间序列,其中每个变... 航迹预测在确保空中交通安全、高效运行中扮演着至关重要的角色。所预测的航迹信息是航迹优化、冲突告警等决策工具的输入,而预测准确性取决于模型对航迹序列特征的提取能力。航迹序列数据是具有丰富时空特征的多维时间序列,其中每个变量都呈现出长短期的时间变化模式,并且这些变量之间还存在着相互依赖的空间信息。为了充分提取这种时空特征,本文提出了基于融合时空特征的编码器-解码器(Spatio-Temporal EncoderDecoder,STED)航迹预测模型。在Encoder中使用门控循环单元(Gated Recurrent Unit,GRU)、卷积神经网络(Convolutional Neural Network,CNN)和注意力机制(Attention,AT)构成的双通道网络来分别提取航迹时空特征,Decoder对时空特征进行拼接融合,并利用GRU对融合特征进行学习和递归输出,实现对未来多步航迹信息的预测。利用真实的航迹数据对算法性能进行验证,实验结果表明,所提STED网络模型能够在未来10 min预测范围内进行高精度的短期航迹预测,相比于LSTM、CNN-LSTM和AT-LSTM等数据驱动航迹预测模型具有更高的精度。此外,STED网络模型预测一个航迹点平均耗时为0.002 s,具有良好的实时性。 展开更多
关键词 4D航迹预测 时空特征 encoder-Decoder 门控循环单元
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基于DCAE-AM的轴承健康指标构建
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作者 李名洪 张林鍹 +2 位作者 邱朝洁 郑兴 张盼盼 《轴承》 北大核心 2026年第1期111-119,共9页
在基于数据驱动和深度学习的轴承剩余使用寿命(RUL)预测流程中,构建能准确描述轴承退化状态的健康指标(HI)是至关重要的步骤。针对基于传统特征和无监督学习方法构建的健康指标性能较差,无法合理反映轴承退化状态的问题,使用深度卷积自... 在基于数据驱动和深度学习的轴承剩余使用寿命(RUL)预测流程中,构建能准确描述轴承退化状态的健康指标(HI)是至关重要的步骤。针对基于传统特征和无监督学习方法构建的健康指标性能较差,无法合理反映轴承退化状态的问题,使用深度卷积自编码器(DCAE)从原始振动信号中提取故障特征,考虑到每组特征都具有时间序列的性质,在编码器中引入自注意力机制(AM)自动学习序列内部元素相互关系并赋予不同权重,提出了构建健康指标的DCAE-AM模型。为合理反映轴承的退化过程并避免引入大量的先验知识,使用基于二次函数的标签训练模型。在PHM2012轴承数据集上进行模型验证并设定了失效阈值,相比于PCA,SOM,WGAN,CNN以及DCAE等方法,DCAE-AM模型所构建健康指标的融合性能评分最少提升了7.3%,最多提升了89.7%。 展开更多
关键词 滚动轴承 深度学习 剩余寿命 编码器 监督学习 故障特征
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跨层级特征融合的水面多尺度目标检测算法
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作者 孟喆 冯辉 徐海祥 《武汉理工大学学报(交通科学与工程版)》 2026年第1期111-116,共6页
在真实航行环境中,船舶目标尺度差异大,小目标众多,导致现有的目标检测算法精度较低.针对此问题,设计了一种跨层级特征融合的水面多尺度目标检测算法CLF-DETR(cross-level feature fusion-DETR).通过新增浅层特征编码,提高算法的小目标... 在真实航行环境中,船舶目标尺度差异大,小目标众多,导致现有的目标检测算法精度较低.针对此问题,设计了一种跨层级特征融合的水面多尺度目标检测算法CLF-DETR(cross-level feature fusion-DETR).通过新增浅层特征编码,提高算法的小目标检测能力;引入语义特征增强结构以构建目标与海天背景之间的联系,抑制无用的特征信息;基于四种不同尺度的特征图,设计了一种跨层级注意力特征融合结构,并采用可学习通道拼接方式,通过跨层级的特征交互来计算注意力矩阵,进而引导不同层级间特征融合;在真实海域数据集上进行模型的训练、验证和测试.结果表明:在保证检测实时性的同时,提出的CLF-DETR与现有优势算法相比,在水面多尺度目标检测精度上有显著提升. 展开更多
关键词 目标检测 多尺度目标 浅层特征编码 语义特征增强 跨层级注意力特征融合
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双阶段双分支模型的三维点云去噪
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作者 权思文 张淑婷 +3 位作者 赵河彬 聂子铭 胡忠文 杨佳琪 《中国图象图形学报》 北大核心 2026年第1期261-272,共12页
目的三维点云数据在三维重建、自动驾驶等领域有着广泛应用,然而由于传感器设备受限和环境因素,点云数据不可避免地受到噪声影响,降低了数据质量,进而影响了后续处理和分析的准确性。现有的基于深度学习的点云去噪主流方法大多采取单阶... 目的三维点云数据在三维重建、自动驾驶等领域有着广泛应用,然而由于传感器设备受限和环境因素,点云数据不可避免地受到噪声影响,降低了数据质量,进而影响了后续处理和分析的准确性。现有的基于深度学习的点云去噪主流方法大多采取单阶段单分支去噪流程,导致模型学习到的特征的表达能力有限,难以捕捉点云复杂的结构信息。因此,提出一种双阶段双分支模型用于三维点云去噪,旨在获得综合点云特征。方法阶段1:利用双分支编码器提取点云块局部和全局特征,并用交叉注意力融合;阶段2:利用注意力机制增强阶段1特征,聚焦强特征表达。最终,加权融合两阶段解码位移,指导点云去噪。结果在3个数据集上与较新的6种方法进行比较,在PUNet(point cloud upsampling network)数据集上,相比Pointfilter取得3个最佳性能、2个次佳性能,双分支双编码器模型取得6个最佳性能、3个次佳性能;在PCNet(point clean network)数据集上,相比于IterativePFN取得2个最佳性能、6个次佳性能,双分支双编码器模型取得7个最佳性能、3个次佳性能;在Kinect_v1数据集上,相比于同期最优模型,双阶段双分支模型在两种指标上取得次佳效果,整体达到最佳。结论本文所提出的双阶段双分支模型的三维点云去噪,解决了点云数据块局部特征和全局特征的提取和融合问题,实现了更好的去噪效果。 展开更多
关键词 深度学习 三维点云去噪 双分支编码器 特征融合 注意力机制
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