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National Data of Class A, B, and C Communicable Diseases in September 2013 in China 被引量:2
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作者 Center for Public Health Surveillance and Information Service,China CDC 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2013年第10期874-874,共1页
关键词 AHC National data of class A and C Communicable Diseases in September 2013 in China HPAI
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National Data of Class A,B,and C Communicable Diseases in October 2013 in China
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《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2013年第11期944-944,共1页
关键词 National data of class A B and C Communicable Diseases in October 2013 in China
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National Data of Class A,B and C Communicable Diseases in August 2013 in China
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《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2013年第9期785-785,共1页
关键词 National data of class A B and C Communicable Diseases in August 2013 in China
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Discriminant Models for Uncertainty Characterization in Area Class Change Categorization
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作者 Jingxiong Zhang Jiong You 《Geo-Spatial Information Science》 2011年第4期255-261,共7页
Discriminant space defining area classes is an important conceptual construct for uncertainty characterization in area-class maps.Discriminant models were promoted as they can enhance consistency in area-class mapping... Discriminant space defining area classes is an important conceptual construct for uncertainty characterization in area-class maps.Discriminant models were promoted as they can enhance consistency in area-class mapping and replicability in error modeling.As area classes are rarely completely separable in empirically realized discriminant space,where class inseparabil-ity becomes more complicated for change categorization,we seek to quantify uncertainty in area classes(and change classes)due to measurement errors and semantic discrepancy separately and hence assess their relative margins objectively.Experiments using real datasets were carried out,and a Bayesian method was used to obtain change maps.We found that there are large differences be-tween uncertainty statistics referring to data classes and information classes.Therefore,uncertainty characterization in change categorization should be based on discriminant modeling of measurement errors and semantic mismatch analysis,enabling quanti-fication of uncertainty due to partially random measurement errors,and systematic categorical discrepancies,respectively. 展开更多
关键词 UNCERTAINTY information classes data classes discriminant models conditional simulation land cover change
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Misclassification error propagation in land cover change categorization
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作者 ZHANG Jingxiong TANG Yunwei 《Geo-Spatial Information Science》 SCIE EI 2012年第3期171-175,共5页
It is important to describe misclassification errors in land cover maps and to quantify their propagation through geo-processing to resultant information products,such as land cover change maps.Geostatistical simulati... It is important to describe misclassification errors in land cover maps and to quantify their propagation through geo-processing to resultant information products,such as land cover change maps.Geostatistical simulation is widely used in error modeling,as it can generate equal-probable realizations of the fields being considered,which can be summarized to facilitate error propagation analysis.To fix noninvariance in indicator simulation,discriminant space-based methods were proposed to enhance consistency in area-class mapping and replicability in uncertainty modeling,as the former is achieved by imposing means while the latter is ensured by projecting spatio-temporal correlated residuals in discriminant space to geographic space through a mapping process.This paper explores discriminant models for error propagation in land cover change detection,followed by experiments based on bi-temporal remote sensing images.It was found that misclassification error propagation is effectively characterized with discriminant covariate-based stochastic simulation,where spatio-temporal interdependence is taken into account. 展开更多
关键词 error propagation area-class maps land cover change discriminant space data class information class stochastic simulation
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一级干线公路的Panel Data限速模型 被引量:1
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作者 王华荣 孙小端 聂百胜 《公路交通科技》 CAS CSCD 北大核心 2012年第4期114-119,共6页
为使限速值的确定更为客观,避免以往仅以85%位速度作为限速主要依据所存在的缺陷,在剖析合理限速与运行速度、道路特征等约束条件之间所存在逻辑关系的基础上,根据百分位速度与其他限速影响因素所构成变量的数据结构与Panel Data结构的... 为使限速值的确定更为客观,避免以往仅以85%位速度作为限速主要依据所存在的缺陷,在剖析合理限速与运行速度、道路特征等约束条件之间所存在逻辑关系的基础上,根据百分位速度与其他限速影响因素所构成变量的数据结构与Panel Data结构的相似性,引入Panel Data相关建模方法来构建限速与百分位速度等影响因素之间的理论模型。采用逐步回归法与最小二乘虚拟变量相结合的方法来求解最优时点固定效应模型表达式,应用F检验或Hausman检验结果确定Panel Data模型类型及具体表达式,最终确定一级干线公路小型车限速的主要影响因素依次为行人干扰、地形、纵坡、百分位速度,大型车限速的主要影响因素依次为地形、纵坡、行人干扰、出入口密度。最后,应用统计软件分别对一级干线公路大、小型车Panel Data限速模型残差有效性进行检验,结果表明所建模型误差均在±10 km/h之内,说明所提出的限速确定方法在实际应用中具备一定的可行性。 展开更多
关键词 交通工程 一级干线公路 PANEL data线性回归模型 限速
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An Optimal Big Data Analytics with Concept Drift Detection on High-Dimensional Streaming Data 被引量:1
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作者 Romany F.Mansour Shaha Al-Otaibi +3 位作者 Amal Al-Rasheed Hanan Aljuaid Irina V.Pustokhina Denis A.Pustokhin 《Computers, Materials & Continua》 SCIE EI 2021年第9期2843-2858,共16页
Big data streams started becoming ubiquitous in recent years,thanks to rapid generation of massive volumes of data by different applications.It is challenging to apply existing data mining tools and techniques directl... Big data streams started becoming ubiquitous in recent years,thanks to rapid generation of massive volumes of data by different applications.It is challenging to apply existing data mining tools and techniques directly in these big data streams.At the same time,streaming data from several applications results in two major problems such as class imbalance and concept drift.The current research paper presents a new Multi-Objective Metaheuristic Optimization-based Big Data Analytics with Concept Drift Detection(MOMBD-CDD)method on High-Dimensional Streaming Data.The presented MOMBD-CDD model has different operational stages such as pre-processing,CDD,and classification.MOMBD-CDD model overcomes class imbalance problem by Synthetic Minority Over-sampling Technique(SMOTE).In order to determine the oversampling rates and neighboring point values of SMOTE,Glowworm Swarm Optimization(GSO)algorithm is employed.Besides,Statistical Test of Equal Proportions(STEPD),a CDD technique is also utilized.Finally,Bidirectional Long Short-Term Memory(Bi-LSTM)model is applied for classification.In order to improve classification performance and to compute the optimum parameters for Bi-LSTM model,GSO-based hyperparameter tuning process is carried out.The performance of the presented model was evaluated using high dimensional benchmark streaming datasets namely intrusion detection(NSL KDDCup)dataset and ECUE spam dataset.An extensive experimental validation process confirmed the effective outcome of MOMBD-CDD model.The proposed model attained high accuracy of 97.45%and 94.23%on the applied KDDCup99 Dataset and ECUE Spam datasets respectively. 展开更多
关键词 Streaming data concept drift classification model deep learning class imbalance data
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基于Multi-class SVM的车辆换道行为识别模型研究 被引量:19
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作者 陈亮 冯延超 李巧茹 《安全与环境学报》 CAS CSCD 北大核心 2020年第1期193-199,共7页
自动安全换道是车辆实现无人驾驶的关键,为精确识别行驶车辆换道状态,保证行车安全,设计了一种基于多分类支持向量机(Multi-class Support Vector Machine,Multiclass SVM)的车辆换道识别模型。从NGSIM数据集中选取美国101公路车辆轨迹... 自动安全换道是车辆实现无人驾驶的关键,为精确识别行驶车辆换道状态,保证行车安全,设计了一种基于多分类支持向量机(Multi-class Support Vector Machine,Multiclass SVM)的车辆换道识别模型。从NGSIM数据集中选取美国101公路车辆轨迹数据进行分类处理,并将车辆换道过程划分为车辆跟驰阶段、车辆换道准备阶段和车辆换道执行阶段。采用网格搜索结合粒子群优化算法(Grid Search-PSO)对SVM模型中惩罚参数C和核参数g进行寻优标定,利用多分类支持向量机换道识别模型对样本数据进行训练和测试,模型测试精度达97.68%。研究表明,模型能够很好地识别车辆在换道过程中的行为状态,为车辆换道阶段的研究提供支持。 展开更多
关键词 安全工程 多分类支持向量机 NGSIM数据 车辆换道识别
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类级代码异味的半监督学习检测方法
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作者 瞿志豪 陈军华 高建华 《计算机工程与设计》 北大核心 2025年第10期2741-2747,共7页
基于机器学习的代码异味检测面临数据集较小、缺乏系统性以及手动注释耗时等挑战,限制了模型性能的提升。为此分析了一种代码异味的半监督学习检测方法,旨在通过结合未标注数据和有限标注数据来提高监督学习分类器的性能。实验结果表明... 基于机器学习的代码异味检测面临数据集较小、缺乏系统性以及手动注释耗时等挑战,限制了模型性能的提升。为此分析了一种代码异味的半监督学习检测方法,旨在通过结合未标注数据和有限标注数据来提高监督学习分类器的性能。实验结果表明,半监督学习分类器(semi supervised learning classifier)的性能明显优于监督学习分类器,在Data Class和Feature Envy两种代码异味检测中,F-measure分别提高了3%的和10%。 展开更多
关键词 代码异味 机器学习 监督学习 半监督学习 半监督学习分类器 Feature Envy data class
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Geological Database for Plate Tectonic Reconstruction:A Conceptual Model
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作者 WANG Ping LIU Shaofeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第S01期66-69,共4页
We all live on one planet and geology has no borders.Countries that reside on different continents share the same architecture beneath the surface;they were once neighbors with common foundations.Interoperable geologi... We all live on one planet and geology has no borders.Countries that reside on different continents share the same architecture beneath the surface;they were once neighbors with common foundations.Interoperable geological data are now freely available to everyone for the benefit of society,demonstrating that geoscience can address both global and regional problems.Whilst increasingly large datasets("Big Data")provide clear opportunities(e.g.,Spina,2018). 展开更多
关键词 PLATE TECTONIC RECONSTRUCTION BIG data GML data model feature class
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Study and Implementation of Web Mining Classification Algorithm Based on Building Tree of Detection Class Threshold
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作者 陈俊杰 宋瀚涛 陆玉昌 《Journal of Beijing Institute of Technology》 EI CAS 2005年第2期126-129,共4页
A new classification algorithm for web mining is proposed on the basis of general classification algorithm for data mining in order to implement personalized information services. The building tree method of detecting... A new classification algorithm for web mining is proposed on the basis of general classification algorithm for data mining in order to implement personalized information services. The building tree method of detecting class threshold is used for construction of decision tree according to the concept of user expectation so as to find classification rules in different layers. Compared with the traditional C4.5 algorithm, the disadvantage of excessive adaptation in C4.5 has been improved so that classification results not only have much higher accuracy but also statistic meaning. 展开更多
关键词 data mining classification algorithm class threshold induced concept
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Predicting Causes of Traffic Road Accidents Using Multi-class Support Vector Machines
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作者 Elfadil A. Mohamed 《通讯和计算机(中英文版)》 2014年第5期441-447,共7页
关键词 道路交通事故 支持向量机 原因 预测 阿拉伯联合酋长国 多级 数据挖掘技术 肇事车辆
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Prediction of Peptides Binding to Major Histocompatibility Class II Molecules Using Machine Learning Methods
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作者 Fateme Kazemi Faramarzi Majid Mohammad Beigi +1 位作者 Yasamin Botorabi Najme Mousavi 《Engineering(科研)》 2013年第10期513-517,共5页
In daily life,we are frequently attacked by infection organisms such as bacteria and viruses. Major Histocompatibility (MHC) molecules have an essential role in T-cell activation and initiating an adaptive immune resp... In daily life,we are frequently attacked by infection organisms such as bacteria and viruses. Major Histocompatibility (MHC) molecules have an essential role in T-cell activation and initiating an adaptive immune response. Development of methods for prediction of MHC-Peptide binding is important in vaccine design and immunotherapy. In this study, we try to predict the binding between peptides and MHC class II. Support vector machine (SVM) and Multi-Layer Percep-tron (MLP) are used for classification. These classifiers based on pseudo amino acid compositions of data that we ex-tracted from PseAAC server, classify the data. Since, the dataset, used in this work, is imbalanced, we apply a pre-processing step to over-sample the minority class and come over this problem. The results show that using the concept of pseudo amino acid composition and applying over-sampling method, increases the performance of predictor. Fur-thermore, the results demonstrate that using the concept of PseAAC and SVM is a successful method for the prediction of MHC class II molecules. 展开更多
关键词 MHC class II Imbalanced data SMOTE SVM
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基于类不平衡学习的离心泵故障诊断研究
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作者 陈志辉 曹思民 +3 位作者 李耀武 赵雪岑 马剑 黄俊杰 《测控技术》 2025年第7期26-34,共9页
旋转机械在运行过程中所采集的故障数据与正常数据存在着“类不平衡”问题,导致以数据为驱动的故障诊断模型准确度下降。针对该问题,以离心泵为对象,通过“两步走”的方式实现离心泵的精准故障诊断。首先,基于带有惩罚梯度的Wasserstei... 旋转机械在运行过程中所采集的故障数据与正常数据存在着“类不平衡”问题,导致以数据为驱动的故障诊断模型准确度下降。针对该问题,以离心泵为对象,通过“两步走”的方式实现离心泵的精准故障诊断。首先,基于带有惩罚梯度的Wasserstein距离生成对抗网络(Wasserstein Generative Adversarial Network with Gradient Penalty,WGAN-GP)模型,实现离心泵故障样本的高质量扩充。其次,利用深度学习卷积神经网络(Convolutional Neural Network,CNN)方法,设计了离心泵的故障诊断模型,并构造了3组不同平衡比例离心泵样本集和平衡样本集,完成了对离心泵的精准故障诊断。实验结果表明,经WGAN-GP模型扩充的样本集对于离心泵故障诊断具有正效益,能够有效提高离心泵的故障诊断准确度。 展开更多
关键词 离心泵 类不平衡数据 故障诊断 生成对抗网络
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基于三维框架的我国“双一流”高校数据治理政策典型特征分析
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作者 李春林 李莉 《华北理工大学学报(社会科学版)》 2025年第6期83-90,共8页
数据已经成为高校发展的关键战略资源,数据治理成为推动高等教育高质量发展的重要工具。以我国“双一流”高校数据治理政策为研究对象,构建“数据治理战略—数据治理任务—数据治理保障”三维分析框架,应用文本分析方法,深入探究我国一... 数据已经成为高校发展的关键战略资源,数据治理成为推动高等教育高质量发展的重要工具。以我国“双一流”高校数据治理政策为研究对象,构建“数据治理战略—数据治理任务—数据治理保障”三维分析框架,应用文本分析方法,深入探究我国一流高校数据治理政策特征。研究表明:数据治理战略维度,目标导向明确、数据定义系统化、治理原则明晰;数据治理任务维度,以数据维护与数据安全为核心、全流程治理覆盖,但质量管理和平台建设薄弱、数据标准有待统一;数据治理保障维度,制度设计与执行机制相对完善,但技术支撑与经费保障不足。最后提出优化对策。 展开更多
关键词 “双一流”高校 数据治理 政策文本 典型特征
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基于加权与动态选择的不平衡数据流分类算法
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作者 韩萌 李春鹏 +3 位作者 李昂 孟凡兴 何菲菲 张瑞华 《计算机工程与应用》 北大核心 2025年第10期79-95,共17页
在数据挖掘领域中,数据流挖掘是一项关键任务,旨在处理不断产生和演化的数据流。与传统的批处理数据挖掘不同,数据流挖掘强调对实时数据的处理和分析,具有更高的时效性和实用性。然而,现实世界的数据流中存在多类别不平衡、变化的类别... 在数据挖掘领域中,数据流挖掘是一项关键任务,旨在处理不断产生和演化的数据流。与传统的批处理数据挖掘不同,数据流挖掘强调对实时数据的处理和分析,具有更高的时效性和实用性。然而,现实世界的数据流中存在多类别不平衡、变化的类别不平衡比和概念漂移等实际挑战,会极大地降低分类器的性能。针对这些问题,提出了一种基于加权与动态选择的不平衡数据流分类算法(sample difficulty weighting and dynamic ensemble selection,SDW-DES),通过综合考虑样本难度和数据动态性,为实时应用提供可靠解决方案。引入一种基于样本分类难度的加权策略,结合样本的边际值和Focal Loss,以更有效地关注易分类错误的样本和少数类样本,从而提高分类器的准确性。提出一种灵活的动态集成选择方法,通过设计样本滑动窗口和困难样本滑动窗口,来综合分析分类器在不同窗口上的表现并加权,选出集成中最好的分类器进行预测,以适应数据分布的动态变化。在多种数据流环境和评估指标上与9种先进的算法进行了全面的实验评估,实验结果表明SDW-DES在4个评估指标中平均排名第一,并且更能够适应数据流中的不平衡和概念漂移问题。 展开更多
关键词 数据流分类 多类不平衡 概念漂移 样本加权 动态集成选择
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有限标签下的非平衡数据流分类方法
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作者 李艳红 李志华 +2 位作者 郑建兴 白鹤翔 郭鑫 《大数据》 2025年第2期107-126,共20页
数据流分类是数据流挖掘的重要研究内容,其核心任务是从实时到达的数据流中快速捕获概念漂移,并及时调整分类模型。极限学习机具有训练速度快和泛化性能好的优点,然而目前基于极限学习机的数据流分类方法很少可以同时处理数据流中常见... 数据流分类是数据流挖掘的重要研究内容,其核心任务是从实时到达的数据流中快速捕获概念漂移,并及时调整分类模型。极限学习机具有训练速度快和泛化性能好的优点,然而目前基于极限学习机的数据流分类方法很少可以同时处理数据流中常见的多类非平衡、概念漂移、标签成本昂贵的问题。为此,提出了一种有限标签下的非平衡数据流分类方法。该方法定义了预测概率差值与信息熵相结合的样本预测确定性度量,提出了不确定性标签请求策略;定义了基于类不平衡比率和样本预测误差的样本重要性度量;提出了基于概念漂移指数的分类器的更新与重构机制。在6个人工数据流和3个真实数据流上的对比实验表明,本文提出方法的分类性能优于已有的6种数据流分类方法的分类性能。 展开更多
关键词 数据流分类 多类非平衡 极限学习机 概念漂移 标签成本昂贵
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基于大数据的职业教育评价助力纺织材料识别与应用课程建设研究
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作者 吴佳林 秦春英 +2 位作者 刘梦林 陶培培 杨璧玲 《山东纺织经济》 2025年第9期46-49,共4页
本文以纺织材料识别与应用课程为例,探讨基于大数据的职业教育评价如何助力课程优化与人才培养。通过整合多源数据,构建动态评价模型,实现对学生知识掌握、技能应用及创新能力的精准评估。基于大数据的评价方法,有效推动课程设计优化。... 本文以纺织材料识别与应用课程为例,探讨基于大数据的职业教育评价如何助力课程优化与人才培养。通过整合多源数据,构建动态评价模型,实现对学生知识掌握、技能应用及创新能力的精准评估。基于大数据的评价方法,有效推动课程设计优化。通过构建纺织材料识别与应用课程的教学评价指标体系,提升教学质量,实现学习路径的可视化与个性化,从而为纺织行业培养具备数字化素养的高技能人才提供科学依据。 展开更多
关键词 新质生产力 大数据技术 评价体系 智慧课堂
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On Statistical Measures for Data Quality Evaluation 被引量:1
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作者 Xiaoxia Han 《Journal of Geographic Information System》 2020年第3期178-187,共10页
<span style="font-family:Verdana;">Most GIS databases contain data errors. The quality of the data sources such as traditional paper maps or more recent remote sensing data determines spatial data qual... <span style="font-family:Verdana;">Most GIS databases contain data errors. The quality of the data sources such as traditional paper maps or more recent remote sensing data determines spatial data quality. In the past several decades, different statistical measures have been developed to evaluate data quality for different types of data, such as nominal categorical data, ordinal categorical data and numerical data. Although these methods were originally proposed for medical research or psychological research, they have been widely used to evaluate spatial data quality. In this paper, we first review statistical methods for evaluating data quality, discuss under what conditions we should use them and how to interpret the results, followed by a brief discussion of statistical software and packages that can be used to compute these data quality measures.</span> 展开更多
关键词 GIS data Quality Sensitivity SPECIFICITY KAPPA Weighted Kappa Bland-Altman Analysis Intra-class Correlation Coefficient
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基于类注意力的原型网络改进方法 被引量:3
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作者 曹增辉 陈浩 曹雅慧 《自动化与信息工程》 2025年第1期59-65,共7页
小样本学习是图像分类任务中的一个重要挑战,能够有效解决因数据量较少而产生的模型准确率降低的问题。针对小样本学习难以准确获取类内共有特征的问题,提出一种基于类注意力的原型网络改进方法。利用掩膜图像进行数据预处理和图像增强... 小样本学习是图像分类任务中的一个重要挑战,能够有效解决因数据量较少而产生的模型准确率降低的问题。针对小样本学习难以准确获取类内共有特征的问题,提出一种基于类注意力的原型网络改进方法。利用掩膜图像进行数据预处理和图像增强,以提高原始数据质量;引入注意力机制,选择性地关注特征图中的重要信息,以增强特征提取能力;设计类注意力模块,提取具有注意力信息的类别原型。实验结果表明,在miniImageNet数据集上,该方法的分类准确率在基线基础上提高了2%,验证了其有效性。 展开更多
关键词 原型网络 小样本学习 数据增强 类注意力 图像分类
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