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Robust Machine Learning Technique to Classify COVID-19 Using Fusion of Texture and Vesselness of X-Ray Images
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作者 Shaik Mahaboob Basha Victor Hugo Cde Albuquerque +3 位作者 Samia Allaoua Chelloug Mohamed Abd Elaziz Shaik Hashmitha Mohisin Suhail Parvaze Pathan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1981-2004,共24页
Manual investigation of chest radiography(CXR)images by physicians is crucial for effective decision-making in COVID-19 diagnosis.However,the high demand during the pandemic necessitates auxiliary help through image a... Manual investigation of chest radiography(CXR)images by physicians is crucial for effective decision-making in COVID-19 diagnosis.However,the high demand during the pandemic necessitates auxiliary help through image analysis and machine learning techniques.This study presents a multi-threshold-based segmentation technique to probe high pixel intensity regions in CXR images of various pathologies,including normal cases.Texture information is extracted using gray co-occurrence matrix(GLCM)-based features,while vessel-like features are obtained using Frangi,Sato,and Meijering filters.Machine learning models employing Decision Tree(DT)and RandomForest(RF)approaches are designed to categorize CXR images into common lung infections,lung opacity(LO),COVID-19,and viral pneumonia(VP).The results demonstrate that the fusion of texture and vesselbased features provides an effective ML model for aiding diagnosis.The ML model validation using performance measures,including an accuracy of approximately 91.8%with an RF-based classifier,supports the usefulness of the feature set and classifier model in categorizing the four different pathologies.Furthermore,the study investigates the importance of the devised features in identifying the underlying pathology and incorporates histogrambased analysis.This analysis reveals varying natural pixel distributions in CXR images belonging to the normal,COVID-19,LO,and VP groups,motivating the incorporation of additional features such as mean,standard deviation,skewness,and percentile based on the filtered images.Notably,the study achieves a considerable improvement in categorizing COVID-19 from LO,with a true positive rate of 97%,further substantiating the effectiveness of the methodology implemented. 展开更多
关键词 Chest radiography(CXR)image COVID-19 classifier machine learning random forest texture analysis
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Machine learning-powered recognition of crystalline phases and orientations in epitaxial Y-doped HfO_(2)via atomicresolution STEM
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作者 Haneul Choi Keun Won Lee +7 位作者 Hyung-Jin Choi Jun Young Lee Jun Hyeok Choi Yoon Jung Won Seung-Hyub Baek Young-Kook Lee Ki Sub Cho Hye Jung Chang 《npj Computational Materials》 2025年第1期3940-3949,共10页
This study presents an efficient method for automatically identifying the crystal structure and orientation of Y-doped HfO_(2)-based thin films using deep learning.This approach enables large-scale crystallographic an... This study presents an efficient method for automatically identifying the crystal structure and orientation of Y-doped HfO_(2)-based thin films using deep learning.This approach enables large-scale crystallographic analysis with sub-nanometer spatial resolution using only scanning transmission electron microscopy(STEM)atomic images,thereby reducing the reliance on manual expert interpretation.The Xception network-based model extracts detailed crystallographic information through structure and entropy maps,effectively identifying subtle pattern changes and local structural discontinuities.Entropy maps are utilized to analyze the atomic structure disorder and detect ambiguous boundaries and strained regions.Analysis of Y-doped HfO_(2)thin films reveals that the film thickness significantly affects the ferroelectric properties,with theOphase dominant in 5 nmfilms and the M phase proportion increasing as the thickness increases.This machine-learning-based STEM atomic image analysis method provides an automated solution to accelerate ferroelectric material research and promote the development of next-generation electronic devices,offering an accurate understanding and control of microstructural characteristics. 展开更多
关键词 structure entropy mapseff deep learningthis Y doped HfO crystallographic analysis crystalline phases atomic resolution STEM crystal structure orientation machine learning
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A Learning Model to Detect Android C&C Applications Using Hybrid Analysis
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作者 Attia Qammar Ahmad Karim +2 位作者 Yasser Alharbi Mohammad Alsaffar Abdullah Alharbi 《Computer Systems Science & Engineering》 SCIE EI 2022年第12期915-930,共16页
Smartphone devices particularly Android devices are in use by billions of people everywhere in the world.Similarly,this increasing rate attracts mobile botnet attacks which is a network of interconnected nodes operate... Smartphone devices particularly Android devices are in use by billions of people everywhere in the world.Similarly,this increasing rate attracts mobile botnet attacks which is a network of interconnected nodes operated through the command and control(C&C)method to expand malicious activities.At present,mobile botnet attacks launched the Distributed denial of services(DDoS)that causes to steal of sensitive data,remote access,and spam generation,etc.Consequently,various approaches are defined in the literature to detect mobile botnet attacks using static or dynamic analysis.In this paper,a novel hybrid model,the combination of static and dynamic methods that relies on machine learning to detect android botnet applications is proposed.Furthermore,results are evaluated using machine learning classifiers.The Random Forest(RF)classifier outperform as compared to other ML techniques i.e.,Naïve Bayes(NB),Support Vector Machine(SVM),and Simple Logistic(SL).Our proposed framework achieved 97.48%accuracy in the detection of botnet applications.Finally,some future research directions are highlighted regarding botnet attacks detection for the entire community. 展开更多
关键词 Android botnet botnet detection hybrid analysis machine learning classifiers mobile malware
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Investigations on Multiclass Classification Model-Based Optimized Weights Spectrum for Rotating Machinery Condition Monitoring
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作者 Bingchang Hou Yu Wang Dong Wang 《Journal of Dynamics, Monitoring and Diagnostics》 2025年第3期194-202,共9页
Machinery condition monitoring is beneficial to equipment maintenance and has been receiving much attention from academia and industry.Machine learning,especially deep learning,has become popular for machinery conditi... Machinery condition monitoring is beneficial to equipment maintenance and has been receiving much attention from academia and industry.Machine learning,especially deep learning,has become popular for machinery condition monitoring because that can fully use available data and computational power.Since significant accidents might be caused if wrong fault alarms are given for machine condition monitoring,interpretable machine learning models,integrate signal processing knowledge to enhance trustworthiness of models,are gradually becoming a research hotspot.A previous spectrum-based and interpretable optimized weights method has been proposed to indicate faulty and fundamental frequencies when the analyzed data only contains a healthy type and a fault type.Considering that multiclass fault types are naturally met in practice,this work aims to explore the interpretable optimized weights method for multiclass fault type scenarios.Therefore,a new multiclass optimized weights spectrum(OWS)is proposed and further studied theoretically and numerically.It is found that the multiclass OWS is capable of capturing the characteristic components associated with different conditions and clearly indicating specific fault characteristic frequencies(FCFs)corresponding to each fault condition.This work can provide new insights into spectrum-based fault classification models,and the new multiclass OWS also shows great potential for practical applications. 展开更多
关键词 machinery condition monitoring optimized weights spectrum spectrum analysis softmax classifier interpretable machine learning model
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Discrimination for minimal hepatic encephalopathy based on Bayesian modeling of default mode network
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作者 焦蕴 王训恒 +2 位作者 汤天宇 朱西琪 滕皋军 《Journal of Southeast University(English Edition)》 EI CAS 2015年第4期582-587,共6页
In order to classify the minimal hepatic encephalopathy (MHE) patients from healthy controls, the independent component analysis (ICA) is used to generate the default mode network (DMN) from resting-state functi... In order to classify the minimal hepatic encephalopathy (MHE) patients from healthy controls, the independent component analysis (ICA) is used to generate the default mode network (DMN) from resting-state functional magnetic resonance imaging (fMRI). Then a Bayesian voxel- wised method, graphical-model-based multivariate analysis (GAMMA), is used to explore the associations between abnormal functional integration within DMN and clinical variable. Without any prior knowledge, five machine learning methods, namely, support vector machines (SVMs), classification and regression trees ( CART ), logistic regression, the Bayesian network, and C4.5, are applied to the classification. The functional integration patterns were alternative within DMN, which have the power to predict MHE with an accuracy of 98%. The GAMMA method generating functional integration patterns within DMN can become a simple, objective, and common imaging biomarker for detecting MIIE and can serve as a supplement to the existing diagnostic methods. 展开更多
关键词 graphical-model-based multivariate analysis bayesian modeling machine learning functional integration minimal hepatic encephalopathy resting-state functional magnetic resonance imaging (fMRI)
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Artificial Intelligence Based Sentence Level Sentiment Analysis of COVID-19
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作者 Sundas Rukhsar Mazhar Javed Awan +5 位作者 Usman Naseem Dilovan Asaad Zebari Mazin Abed Mohammed Marwan Ali Albahar Mohammed Thanoon Amena Mahmoud 《Computer Systems Science & Engineering》 SCIE EI 2023年第10期791-807,共17页
Web-blogging sites such as Twitter and Facebook are heavily influenced by emotions,sentiments,and data in the modern era.Twitter,a widely used microblogging site where individuals share their thoughts in the form of t... Web-blogging sites such as Twitter and Facebook are heavily influenced by emotions,sentiments,and data in the modern era.Twitter,a widely used microblogging site where individuals share their thoughts in the form of tweets,has become a major source for sentiment analysis.In recent years,there has been a significant increase in demand for sentiment analysis to identify and classify opinions or expressions in text or tweets.Opinions or expressions of people about a particular topic,situation,person,or product can be identified from sentences and divided into three categories:positive for good,negative for bad,and neutral for mixed or confusing opinions.The process of analyzing changes in sentiment and the combination of these categories is known as“sentiment analysis.”In this study,sentiment analysis was performed on a dataset of 90,000 tweets using both deep learning and machine learning methods.The deep learning-based model long-short-term memory(LSTM)performed better than machine learning approaches.Long short-term memory achieved 87%accuracy,and the support vector machine(SVM)classifier achieved slightly worse results than LSTM at 86%.The study also tested binary classes of positive and negative,where LSTM and SVM both achieved 90%accuracy. 展开更多
关键词 COVID-19 artificial intelligence machine learning deep learning sentimental analysis support vector classifier
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High-speed encrypted traffic classification by using payload features
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作者 Xinge Yan Liukun He +3 位作者 Yifan Xu Jiuxin Cao Liangmin Wang Guyang Xie 《Digital Communications and Networks》 2025年第2期412-423,共12页
Traffic encryption techniques facilitate cyberattackers to hide their presence and activities.Traffic classification is an important method to prevent network threats.However,due to the tremendous traffic volume and l... Traffic encryption techniques facilitate cyberattackers to hide their presence and activities.Traffic classification is an important method to prevent network threats.However,due to the tremendous traffic volume and limitations of computing,most existing traffic classification techniques are inapplicable to the high-speed network environment.In this paper,we propose a High-speed Encrypted Traffic Classification(HETC)method containing two stages.First,to efficiently detect whether traffic is encrypted,HETC focuses on randomly sampled short flows and extracts aggregation entropies with chi-square test features to measure the different patterns of the byte composition and distribution between encrypted and unencrypted flows.Second,HETC introduces binary features upon the previous features and performs fine-grained traffic classification by combining these payload features with a Random Forest model.The experimental results show that HETC can achieve a 94%F-measure in detecting encrypted flows and a 85%–93%F-measure in classifying fine-grained flows for a 1-KB flow-length dataset,outperforming the state-of-the-art comparison methods.Meanwhile,HETC does not need to wait for the end of the flow and can extract mass computing features.The average time for HETC to process each flow is only 2 or 16 ms,which is lower than the flow duration in most cases,making it a good candidate for high-speed traffic classification. 展开更多
关键词 Traffic classification Flow analysis Information entropy machine learning Randomness test
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江西省资源环境承载力评价研究
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作者 丰娟 刘勇 +1 位作者 唐勇波 龚国勇 《宜春学院学报》 2025年第9期91-98,共8页
通过对江西省资源环境承载力的评价分析,揭示江西省资源环境承载力特征,有利于更好地推进江西省的生态文明建设。基于资源环境承载力内涵,选取29个指标,从资源、环境、经济、社会四个子系统构建江西省资源环境承载力指标体系,采用分类... 通过对江西省资源环境承载力的评价分析,揭示江西省资源环境承载力特征,有利于更好地推进江西省的生态文明建设。基于资源环境承载力内涵,选取29个指标,从资源、环境、经济、社会四个子系统构建江西省资源环境承载力指标体系,采用分类排列多边形图示法计算子系统的承载力水平,然后用熵权法确定资源环境承载力。在此基础上,利用极限学习机建立当年指标变量与次年资源环境承载力的非线性映射关系,并采用灰关联度对影响资源环境承载力的因素进行分析。研究结果表明:在2003—2018年间,江西省资源环境承载力由2003年的0.3083上升到2018年的0.8121,总体呈波动上升趋势,实现了高速增长的非稳定态向理想承载近似稳定态的转变。从子系统上看,经济承载力呈较大幅度的稳定上升趋势,由2003年的0.2742增长到2018年的0.9113,环境承载力呈波动上升趋势,而资源承载力和社会承载力呈现先波动上升,后缓慢回落的趋势。资源、环境、经济、社会这四个子系统对江西省资源环境承载力的提高有促进作用,同时部分因素也有阻碍作用,在工业污染的环境治理方面的需求落后于经济的持续增长,已经成为当前制约资源环境承载力的主要因素。 展开更多
关键词 资源环境承载力 熵权法 极限学习机 灰关联度分析 江西省
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Implementation of an AI-based predictive structural health monitoring strategy for bonded insulated rail joints using digital twins under varied bolt conditions
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作者 G.Bianchi F.Freddi +1 位作者 F.Giuliani A.La Placa 《Railway Engineering Science》 2025年第4期703-720,共18页
Predictive maintenance is essential for the implementation of an innovative and efficient structural health monitoring strategy.Models capable of accurately interpreting new data automatically collected by suitably pl... Predictive maintenance is essential for the implementation of an innovative and efficient structural health monitoring strategy.Models capable of accurately interpreting new data automatically collected by suitably placed sensors to assess the state of the infrastructure represent a fundamental step,particularly for the railway sector,whose safe and continuous operation plays a strategic role in the well-being and development of nations.In this scenario,the benefits of a digital twin of a bonded insu-lated rail joint(IRJ)with the predictive capabilities of advanced classification algorithms based on artificial intelligence have been explored.The digital model provides an accurate mechanical response of the infrastructure as a pair of wheels passes over the joint.As bolt preload conditions vary,four structural health classes were identified for the joint.Two parameters,i.e.gap value and vertical displacement,which are strongly correlated with bolt preload,are used in different combinations to train and test five predictive classifiers.Their classification effectiveness was assessed using several performance indica-tors.Finally,we compared the IRJ condition predictions of two trained classifiers with the available data,confirming their high accuracy.The approach presented provides an interesting solution for future predictive tools in SHM especially in the case of complex systems such as railways where the vehicle-infrastructure interaction is complex and always time varying. 展开更多
关键词 Predictive maintenance Digital twin of bonded insulated rail joints Finite element analysis Artificial intelligence classifier machine learning data analysis Structural health monitoring strategy Railway track monitoring
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基于监督核熵的空压机阀片故障诊断优化 被引量:2
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作者 赵凯 王永坚 +1 位作者 蔡杭溪 李劼 《船海工程》 北大核心 2025年第1期13-19,共7页
空压机作为船舶航行过程中的关键设备,其运行状态的精准识别对船舶安全性能具有重要影响。鉴于空压机在工作过程中振动信息呈现出非平稳和非线性的特点,提出利用监督核熵成分分析对其特征数据选择,旨在通过数据降维保留关键特征信息,将... 空压机作为船舶航行过程中的关键设备,其运行状态的精准识别对船舶安全性能具有重要影响。鉴于空压机在工作过程中振动信息呈现出非平稳和非线性的特点,提出利用监督核熵成分分析对其特征数据选择,旨在通过数据降维保留关键特征信息,将处理后的特征信息输入到经过贝叶斯优化方法优化超参数的支持向量机模型中,以评估其在空压机状态识别方面的性能。经实验验证可知,该方法能够有效提升支持向量机模型的识别准确率,准确率可达98.47%。 展开更多
关键词 船用空压机 阀片故障诊断 监督核熵成分分析 贝叶斯优化 支持向量机
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机器学习方法在治疗效果异质性分析中的应用及中医药领域适用性探讨
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作者 李牧之 王思村 +4 位作者 和晓珺 党海霞 刘骏 王忠 于亚南 《中医杂志》 北大核心 2025年第21期2199-2203,共5页
治疗效果异质性(HTE)分析是对临床研究中不同患者群体治疗效果差异性表现的系统探索,有助于推动个体化治疗策略的实施。机器学习方法对复杂交互作用的识别能力为HTE更准确、高效地获得治疗优势人群提供了可行路径。系统梳理了目前临床... 治疗效果异质性(HTE)分析是对临床研究中不同患者群体治疗效果差异性表现的系统探索,有助于推动个体化治疗策略的实施。机器学习方法对复杂交互作用的识别能力为HTE更准确、高效地获得治疗优势人群提供了可行路径。系统梳理了目前临床研究中HTE分析常用的机器学习模型,归纳为惩罚回归模型、因果树模型、贝叶斯模型和元学习模型四种类型;阐述了不同类别机器学习模型的优缺点及在HTE分析中的适用数据类型,探讨了不同机器学习方法在中医药临床研究中的可能应用场景,以期为在中医药临床研究中应用HTE分析提供方法学支持。 展开更多
关键词 治疗效果异质性分析 机器学习 惩罚回归模型 因果树模型 贝叶斯模型 元学习模型
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基于特征选择的集成极限学习机故障辨识方法
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作者 马驰 赵荣珍 +1 位作者 原健辉 郑玉巧 《兰州理工大学学报》 北大核心 2025年第2期44-50,共7页
针对传统极限学习机神经网络在处理复杂数据时无法获得最佳分类性能的问题,提出了基于特征选择的集成极限学习机故障辨识方法.首先,选择合适的尺度对振动信号进行粗粒化分解,在不同尺度上计算振动信号的模糊近似熵,并构成高维数据集.然... 针对传统极限学习机神经网络在处理复杂数据时无法获得最佳分类性能的问题,提出了基于特征选择的集成极限学习机故障辨识方法.首先,选择合适的尺度对振动信号进行粗粒化分解,在不同尺度上计算振动信号的模糊近似熵,并构成高维数据集.然后,通过邻域粗糙集算法对高维数据集进行属性约简,并且采用不同的邻域半径对数据集进行约简,从而产生不同的特征子集,同时将每个特征子集划分为训练集和测试集,进而输入极限学习机进行模式识别.最后,整合多个极限学习机的预测结果,依据相对多数投票法决定最终的辨识结果.实验证明,相比传统极限学习机,该方法可以提高滚动轴承故障类别的辨识精度,使故障分类结果更准确、更有效. 展开更多
关键词 模糊近似熵 特征选择 分类器集成 极限学习机
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中国式现代化评价指标体系的构建与应用 被引量:5
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作者 张书华 《工业技术经济》 北大核心 2025年第1期150-160,共11页
科学合理地构建中国式现代化评价指标体系并对其进行实证检验和应用不仅具有紧迫性而且具有必要性,也能为规范研究提供丰富的实践论据。本文通过借鉴已有相关评价指标体系,依据科学性、实用性、全面性、简洁性的指标构建原则,建立了包... 科学合理地构建中国式现代化评价指标体系并对其进行实证检验和应用不仅具有紧迫性而且具有必要性,也能为规范研究提供丰富的实践论据。本文通过借鉴已有相关评价指标体系,依据科学性、实用性、全面性、简洁性的指标构建原则,建立了包含经济现代化、政治现代化、文化现代化、社会现代化、生态现代化、军事现代化、人口现代化7个一级指标、29个二级指标、98个三级指标在内的中国式现代化初始评价指标体系。结合机器学习的LASSO筛选变量法,在此基础上再构建出包含7个一级指标、26个二级指标、78个三级指标在内的中国式现代化最终评价指标体系,并根据熵权-TOPSIS法对我国2012~2023年的指标权重和指数进行了分项和综合评价,得出指标权重排序、现代化发展态势、分类重视程度、现代化制约因素等研究结论,继而从统筹推进各领域的协同发展、积极发挥“前十因素”的“火车头”作用、有效补齐迈向高位的制约短板3个方面提出启示对策。 展开更多
关键词 中国式现代化 评价指标体系 量化分析 机器学习 LASSO筛选变量法 熵权-TOPSIS法 实体经济 高质量发展
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面向生成式对抗网络的贝叶斯成员推理攻击
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作者 尚游 缪祥华 《计算机应用》 北大核心 2025年第10期3252-3258,共7页
目前,关于生成式对抗网络(GAN)中成员推理攻击(MIA)的准确率与生成模型自身泛化能力之间的关系存在争议,因此有效的攻击手段难以广泛应用,这限制了生成模型的改进。为了解决上述问题,提出一种基于贝叶斯估计(BE)的灰盒MIA方案,旨在灰盒... 目前,关于生成式对抗网络(GAN)中成员推理攻击(MIA)的准确率与生成模型自身泛化能力之间的关系存在争议,因此有效的攻击手段难以广泛应用,这限制了生成模型的改进。为了解决上述问题,提出一种基于贝叶斯估计(BE)的灰盒MIA方案,旨在灰盒场景下高效匹配参数以实现最优攻击。首先,在黑盒条件下设计目标模型和影子模型的训练框架,以获取攻击模型所需的参数知识;其次,结合并利用这些有效参数信息不断更新目标函数,从而训练攻击模型;最后,将训练好的攻击模型应用于MIA。实验结果表明,与现有的白盒、黑盒攻击方案相比,基于BE的灰盒攻击方案的准确率平均分别提升了15.89%和21.64%。以上研究结果展示了参数暴露与攻击成功率(ASR)之间的直接联系,也为未来该领域开发防御性策略提供了方向。 展开更多
关键词 机器学习 生成式对抗网络 成员推理攻击 贝叶斯估计 关联分析
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脱“虚”向实:数字政府注意力与政策执行力
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作者 赵绪帅 邵祥东 《经济论坛》 2025年第8期139-152,共14页
文章使用机器学习和文本分析法测度数字政府注意力,使用熵值法测度政策执行力,并基于计量分析方法,采用2015—2022年省级面板数据,验证两者之间的关系。研究发现:数字政府注意力和执行力存在相关性,且在东部地区相关较强,在其他地区相... 文章使用机器学习和文本分析法测度数字政府注意力,使用熵值法测度政策执行力,并基于计量分析方法,采用2015—2022年省级面板数据,验证两者之间的关系。研究发现:数字政府注意力和执行力存在相关性,且在东部地区相关较强,在其他地区相关较弱,呈现出一定程度的区域差异,在东北地区和西部地区存在一定程度的错配。主要原因是经济水平差异所致,由于数字资源和技术不足,政策关注难以有效转化和实际执行。建议数字政府建设应当脱“虚”向实,注重政策执行和落地,坚持差异化经济支持政策,促进数字政府建设的均衡发展。 展开更多
关键词 数字政府 政府治理 机器学习 文本分析 熵值法
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微观视角下的高端装备制造业智能化升级路径分析
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作者 李佳蓥 石娟 《天津理工大学学报》 2025年第5期1-10,共10页
在创新资源有限的情况下,高端装备制造业如何加快智能化升级是亟待解决的关键问题。该研究以天津市96家高端装备制造企业为例,借助机器学习的方法研究企业升级的路径,以降低专家分析的主观性。通过国家标准、办法构建了关于高端装备制... 在创新资源有限的情况下,高端装备制造业如何加快智能化升级是亟待解决的关键问题。该研究以天津市96家高端装备制造企业为例,借助机器学习的方法研究企业升级的路径,以降低专家分析的主观性。通过国家标准、办法构建了关于高端装备制造企业升级现状的30个三级指标和9个二级指标,使用因子分析法得到5个关键因子:产业价值链成熟度、资产转化能力、网络基础建设能力、科研人员整体文化程度、新产品活跃度。然后通过熵值法为评价指标体系赋予权重并得到高端装备制造企业关键因子得分,最后投入K-Means聚类模型中进行分析,根据结果将高端装备制造企业分为引领示范型、加快推进型、培育发展型3类,并根据类型的不同给出3条升级路径。因子分析、熵值法以及K-Means聚类结合改进了传统的分析方法,突破了人工分析的局限,可以客观且直观地处理量级更大的数据,为高端装备制造企业智能化升级现状分析和预测提供新思路。 展开更多
关键词 高端装备制造企业 智能化升级路径 因子分析 熵值法 机器学习
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基于机器学习的含油污泥热解残渣含油率预测
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作者 彭黄湖 姜勇 +3 位作者 杨帆 陈泽洲 吴圣姬 车磊 《能源环境保护》 2025年第6期188-198,共11页
为快速预测含油污泥热解后残渣含油率的变化规律,指导含油污泥热解工艺参数优化,选取热解终温,热解时间,升温速率,氮气流量,含油污泥的含油率、含水率和含渣率作为输入变量,热解残渣含油率作为输出变量,采用梯度提升决策树(GBDT)、极端... 为快速预测含油污泥热解后残渣含油率的变化规律,指导含油污泥热解工艺参数优化,选取热解终温,热解时间,升温速率,氮气流量,含油污泥的含油率、含水率和含渣率作为输入变量,热解残渣含油率作为输出变量,采用梯度提升决策树(GBDT)、极端梯度提升(XGB)、支持向量机(SVM)及随机森林(RF)算法分别建立了含油污泥热解残渣含油率的预测模型。通过228组数据进行训练和测试,结果表明,GBDT、XGB、SVM以及RF 4种含油率预测模型在测试集上的决定系数R^(2)分别为0.8716、0.8667、0.8356和0.9171。经过贝叶斯优化算法(BOA)超参优化后,该4种含油率预测模型的测试集决定系数R^(2)分别提升至0.9012、0.9001、0.8965和0.9204。其中,贝叶斯优化的随机森林(BO-RF)模型预测效果更佳,能更准确地预测含油污泥热解残渣含油率的动态变化规律。 展开更多
关键词 含油污泥 热解 含油率预测 特征重要性分析 机器学习 贝叶斯优化算法
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主动贝叶斯网络分类器 被引量:37
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作者 宫秀军 孙建平 史忠植 《计算机研究与发展》 EI CSCD 北大核心 2002年第5期574-579,共6页
在机器学习中 ,主动学习具有很长的研究历史 .给出了主动贝叶斯分类模型 ,并讨论了主动学习中几种常用的抽样策略 .提出了基于最大最小熵的主动学习方法和基于不确定抽样与最小分类损失相结合的主动学习策略 ,给出了增量地分类测试实例... 在机器学习中 ,主动学习具有很长的研究历史 .给出了主动贝叶斯分类模型 ,并讨论了主动学习中几种常用的抽样策略 .提出了基于最大最小熵的主动学习方法和基于不确定抽样与最小分类损失相结合的主动学习策略 ,给出了增量地分类测试实例和修正分类参数的方法 .人工和实际的数据实验结果表明 。 展开更多
关键词 主动学习 贝叶斯网络分类器 最大最小熵 分类损失 机器学习
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用于数据采掘的贝叶斯分类器研究 被引量:32
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作者 林士敏 田凤占 陆玉昌 《计算机科学》 CSCD 北大核心 2000年第10期73-76,共4页
所谓分类器是一个函数f(x),它给需要分类的实例x赋予类标签c,∈C(j=1,2,…,m),实例x由一组属性值a_1,…,a_n描述,C是类变量,取有限个值,可看成有限个元素的集合。进行分类首先要构造一个分类器。从预先分类的实例进行有导师学习并建立... 所谓分类器是一个函数f(x),它给需要分类的实例x赋予类标签c,∈C(j=1,2,…,m),实例x由一组属性值a_1,…,a_n描述,C是类变量,取有限个值,可看成有限个元素的集合。进行分类首先要构造一个分类器。从预先分类的实例进行有导师学习并建立分类器,是机器学习的中心问题之一。已有的分类器如决策树、决策表、神经网络、决策图和规则等。 展开更多
关键词 数据采掘 数据库 贝叶斯分类器 机器学习
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远程教学系统中的自动问题回答子系统设计 被引量:9
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作者 杨清 杨岳湘 瞿国平 《计算机工程》 CAS CSCD 北大核心 2000年第2期63-64,67,共3页
介绍了远程教学系统中的一种自动问题回答子系统设计。它是利用机器学习的方法,从已存在的知识库中构造出问题分类模型。另一方面,对学生的问题进行特征提炼,最后,利用相关的算法从知识库中返回学生问题的最佳答案。
关键词 机器学习 分类器 条件概率 知识库 信息熵
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