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深层次标签辅助分类任务的层次标签文本分类方法
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作者 曹渝昆 魏子越 +2 位作者 唐艺嘉 金成坤 李云峰 《计算机工程与应用》 CSCD 北大核心 2024年第10期105-112,共8页
层次标签文本分类是自然语言处理领域中一项具有挑战性的任务,每个文档需要被正确分类到对应具有层次结构的多个标签中。然而在标签集中,由于标签包含的语义信息不充分,同时被归类到深层次标签的文档数量过少,深层次标签训练不充分,导... 层次标签文本分类是自然语言处理领域中一项具有挑战性的任务,每个文档需要被正确分类到对应具有层次结构的多个标签中。然而在标签集中,由于标签包含的语义信息不充分,同时被归类到深层次标签的文档数量过少,深层次标签训练不充分,导致显著的标签训练不平衡问题。基于此,提出了深层次标签辅助分类任务的层次标签文本分类方法(DLAC)。该方法提出了一种深层次标签辅助分类器,在标签语义增强的基础上有效利用文本特征与深层次标签对应的父标签结点(即浅层次标签的丰富特征)来提升深层次标签的分类性能。与11种算法在三个数据集上的对比实验结果表明,模型能够有效提升深层次标签的分类性能,并取得良好效果。 展开更多
关键词 层次标签文本分类 标签层次结构 全局标签分类通道 深层次标签辅助分类通道
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基于主辅通道的盲源分离抗主瓣干扰算法 被引量:1
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作者 王志刚 朱灿 +1 位作者 洪畅 翟栋梁 《雷达与对抗》 2019年第4期10-14,共5页
针对传统抗干扰算法难以有效抑制雷达主瓣干扰的问题,提出一种基于主辅通道的盲源分离抗主瓣干扰算法。构建雷达抗主瓣干扰的信号模型,并对信源数目进行估计。利用基于矩阵联合对角化特征矢量的盲分离算法分离主瓣目标和干扰混合信号。... 针对传统抗干扰算法难以有效抑制雷达主瓣干扰的问题,提出一种基于主辅通道的盲源分离抗主瓣干扰算法。构建雷达抗主瓣干扰的信号模型,并对信源数目进行估计。利用基于矩阵联合对角化特征矢量的盲分离算法分离主瓣目标和干扰混合信号。基于时域峰均值功率比评估指标实现目标和干扰通道分类。仿真实验表明,提出的信源估计和通道分类算法准确有效,同时盲源分离在复杂电磁环境中具有良好的抗干扰性能。 展开更多
关键词 盲源分离 抗主瓣干扰 信源估计 通道分类
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Infrasound Event Classification Fusion Model Based on Multiscale SE-CNN and BiLSTM
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作者 Hongru Li Xihai Li +3 位作者 Xiaofeng Tan Chao Niu Jihao Liu Tianyou Liu 《Applied Geophysics》 SCIE CSCD 2024年第3期579-592,620,共15页
The classification of infrasound events has considerable importance in improving the capability to identify the types of natural disasters.The traditional infrasound classification mainly relies on machine learning al... The classification of infrasound events has considerable importance in improving the capability to identify the types of natural disasters.The traditional infrasound classification mainly relies on machine learning algorithms after artificial feature extraction.However,guaranteeing the effectiveness of the extracted features is difficult.The current trend focuses on using a convolution neural network to automatically extract features for classification.This method can be used to extract signal spatial features automatically through a convolution kernel;however,infrasound signals contain not only spatial information but also temporal information when used as a time series.These extracted temporal features are also crucial.If only a convolution neural network is used,then the time dependence of the infrasound sequence will be missed.Using long short-term memory networks can compensate for the missing time-series features but induces spatial feature information loss of the infrasound signal.A multiscale squeeze excitation–convolution neural network–bidirectional long short-term memory network infrasound event classification fusion model is proposed in this study to address these problems.This model automatically extracted temporal and spatial features,adaptively selected features,and also realized the fusion of the two types of features.Experimental results showed that the classification accuracy of the model was more than 98%,thus verifying the effectiveness and superiority of the proposed model. 展开更多
关键词 infrasound classification channel attention convolution neural network bidirectional long short-term memory network multiscale feature fusion
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非采样Contourlet变换与局部二值模式相结合的人脸识别 被引量:5
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作者 岳许要 杨恢先 +2 位作者 祝贵 冷爱莲 李利 《计算机应用》 CSCD 北大核心 2012年第7期1890-1893,共4页
针对人脸识别中姿态、光照和表情变化带来的识别率有限的问题,提出了一种基于非采样Contourlet变换(NSCT)与局部二值模式(LBP)的人脸特征提取方法。首先对人脸图像进行非采样Contourlet变换,得到多尺度、多方向的子带系数矩阵,然后利用... 针对人脸识别中姿态、光照和表情变化带来的识别率有限的问题,提出了一种基于非采样Contourlet变换(NSCT)与局部二值模式(LBP)的人脸特征提取方法。首先对人脸图像进行非采样Contourlet变换,得到多尺度、多方向的子带系数矩阵,然后利用LBP算子从每个子带系数矩阵上抽取局部邻域关系,得到各子带的LBP特征图谱,最后将这些图谱分块统计并级联后作为人脸的识别特征。利用多通道最近邻分类器的分类结果表明,所提方法能有效提高识别率,所提取的特征对光照、表情和姿态等变化具有更好的鲁棒性。 展开更多
关键词 人脸识别 非采样CONTOURLET变换 局部二值模式 通道最近邻分类
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A 3D-QSAR Study on a Novel Chromanol Class of I_ (Ks) Potassium Channel Blockers
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作者 杜吕佩 李敏勇 +1 位作者 夏霖 尤启冬 《Journal of Chinese Pharmaceutical Sciences》 CAS 2005年第2期89-94,共6页
Aim and Method A novel three-dimensional quantitative structure-activityrelationship (3D-QSAR) method, self-organizing molecular field analysis (SOMFA) , was used toinvestigate the correlation between the molecular pr... Aim and Method A novel three-dimensional quantitative structure-activityrelationship (3D-QSAR) method, self-organizing molecular field analysis (SOMFA) , was used toinvestigate the correlation between the molecular properties and a class of chromanol analogs asI_(Ks) blockers. Results The cross-validated correlation coefficient q^2 values (0.698) and noncross-validated correlation coefficient r^2 values (0.701) proved a good conventional statisticalcorrelation. Conclusion The final SOMFA model has therefore good predictive activity for the furthermolecular design of chromanol I_(Ks) potassium channel blockers. 展开更多
关键词 quantitative structure-activity relationship self-organizing molecular fieldanalysis I_(Ks) potassium channel blockers chromanol analogs
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量子隐形传态的通用线路 被引量:2
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作者 张国帅 许道云 《软件学报》 EI CSCD 北大核心 2019年第12期3579-3589,共11页
EPR态作为最基本的量子纠缠态,在量子隐形传态中起着重要作用.研究适应任意类型EPR通道的单量子比特隐形传送通用线路,并推广到任意W比特量子隐形传送通用线路.首先设计出4种EPR态,分别作为量子通道的单比特量子隐形传态,通过分析EPR量... EPR态作为最基本的量子纠缠态,在量子隐形传态中起着重要作用.研究适应任意类型EPR通道的单量子比特隐形传送通用线路,并推广到任意W比特量子隐形传送通用线路.首先设计出4种EPR态,分别作为量子通道的单比特量子隐形传态,通过分析EPR量子通道与量子操作门之间的关系,设计一种单比特通用线路;然后,设计两比特的标准量子隐形传态线路,并用Mathematica进行仿真验证线路的正确性,再把它推广到W比特量子隐形传送线路;最后,将单量子比特通用线路与W比特量子隐形传送线路进行融合,最终设计出任意N比特量子隐形传送通用线路.W粒子量子比特通用线路通过信息接受者进行带参数的幺正变换,其中,参数由制备出的EPR对类型确定,解决了因EPR制备中心出错导致的信息传送失败问题. 展开更多
关键词 量子隐形传态 通用线路 EPR态 纠缠态 量子通道中图法分类号:TP301
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Length-Based Vehicle Classification in Multi-lane Traffic Flow 被引量:1
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作者 于洋 于明 +1 位作者 阎刚 翟艳东 《Transactions of Tianjin University》 EI CAS 2011年第5期362-368,共7页
For the realtime classification of moving vehicles in the multi-lane traffic video sequences, a length-based method is proposed. To extract the moving regions of interest, the difference image between the updated back... For the realtime classification of moving vehicles in the multi-lane traffic video sequences, a length-based method is proposed. To extract the moving regions of interest, the difference image between the updated background and current frame is obtained by using background subtraction, and then an edge-based shadow removal algorithm is implemented. Moreover, a tbresholding segmentation method for the region detection of moving vehicle based on lo- cation search is developed. At the estimation stage, a registration line is set up in the detection area, then the vehicle length is estimated with the horizontal projection technique as soon as the vehicle leaves the registration line. Lastly, the vehicle is classified according to its length and the classification threshold. The proposed method is different from traditional methods that require complex camera calibrations. It calculates the pixel-based vehicle length by using uncalibrated traffic video sequences at lower computational cost. Furthermore, only one registration line is set up, which has high flexibility. Experimental results of three traffic video sequences show that the classification accuracies for the large and small vehicles are 97.1% and 96.7% respectively, which demonstrates the effectiveness of the proposed method. 展开更多
关键词 image processing background subtraction vehicle classification virtual line horizontal projection
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感知器残差网络和超限学习机融合的3D物体识别
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作者 黄强 王永雄 《中国图象图形学报》 CSCD 北大核心 2019年第10期1738-1749,共12页
目的随着3D扫描技术和虚拟现实技术的发展,真实物体的3D识别方法已经成为研究的热点之一。针对现有基于深度学习的方法训练时间长,识别效果不理想等问题,提出了一种结合感知器残差网络和超限学习机(ELM)的3D物体识别方法。方法以超限学... 目的随着3D扫描技术和虚拟现实技术的发展,真实物体的3D识别方法已经成为研究的热点之一。针对现有基于深度学习的方法训练时间长,识别效果不理想等问题,提出了一种结合感知器残差网络和超限学习机(ELM)的3D物体识别方法。方法以超限学习机的框架为基础,使用多层感知器残差网络学习3D物体的多视角投影特征,并利用提取的特征数据和已知的标签数据同时训练了ELM分类层、K最近邻(KNN)分类层和支持向量机(SVM)分类层识别3D物体。网络使用增加了多层感知器的卷积层替代传统的卷积层。卷积网络由改进的残差单元组成,包含多个卷积核个数恒定的并行残差通道,用于拟合不同数学形式的残差项函数。网络中半数卷积核参数和感知器参数以高斯分布随机产生,其余通过训练寻优得到。结果提出的方法在普林斯顿3D模型数据集上达到了94.18%的准确率,在2D的NORB数据集上达到了97.46%的准确率。该算法在两个国际标准数据集中均取得了当前最好的效果。同时,使用超限学习机框架使得本文算法的训练时间比基于深度学习的方法减少了3个数量级。结论本文提出了一种使用多视角图识别3D物体的方法,实验表明该方法比现有的ELM方法和深度学习等最新方法的识别率更高,抗干扰性更强,并且其调节参数少,收敛速度快。 展开更多
关键词 多层感知器残差网络 通道分类 超限学习机 3D物体识别 特征提取
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Femoral head fracture without hip dislocation 被引量:2
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作者 Aditya K Aggarwal Ashwani Soni Daljeet Singh 《Chinese Journal of Traumatology》 CAS CSCD 2013年第5期304-307,共4页
Femoral head fractures without disloca- tion or subluxation are extremely rare injuries. We report a neglected case of isolated comminuted fracture of femoral head without hip dislocation or subluxation of one year du... Femoral head fractures without disloca- tion or subluxation are extremely rare injuries. We report a neglected case of isolated comminuted fracture of femoral head without hip dislocation or subluxation of one year duration in a 36-year-old patient who sustained a high en- ergy trauma due to road traffic accident. He presented with painful right hip and inability to bear full weight on right lower limb with Harris hip score of 39. He received cementless total hip replacement. At latest follow-up of 2.3 years, functional outcome was excellent with Harris hip score of 95. Such isolated injuries have been described only once in the literature and have not been classified till now. The purpose of this report is to highlight the extreme rarity, pos- sible mechanism involved and a novel classification system to classify such injuries. 展开更多
关键词 Femur head Hip dislocation CLASSIFICATION Arthroplasty replacement hip
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