期刊文献+
共找到763篇文章
< 1 2 39 >
每页显示 20 50 100
Pairwise Classifier Ensemble with Adaptive Sub-Classifiers for fMRI Pattern Analysis
1
作者 Eunwoo Kim HyunWook Park 《Neuroscience Bulletin》 SCIE CAS CSCD 2017年第1期41-52,共12页
The multi-voxel pattern analysis technique is applied to fMRI data for classification of high-level brain functions using pattern information distributed over multiple voxels. In this paper, we propose a classifier en... The multi-voxel pattern analysis technique is applied to fMRI data for classification of high-level brain functions using pattern information distributed over multiple voxels. In this paper, we propose a classifier ensemble for multiclass classification in fMRI analysis, exploiting the fact that specific neighboring voxels can contain spatial pattern information. The proposed method converts the multiclass classification to a pairwise classifier ensemble, and each pairwise classifier consists of multiple sub-clas- sifiers using an adaptive feature set for each class-pair. Simulated and real fMRI data were used to verify the proposed method. Intra- and inter-subject analyses were performed to compare the proposed method with several well-known classitiers, including single and ensemble classifiers. The comparison results showed that the proposed method can be generally applied to multiclass classification in both simulations and real fMRI analyses. 展开更多
关键词 Ensemble learning Functional MRI Multi-voxel pattern analysis Pairwise classifier
原文传递
Face Recognition Based on Support Vector Machine and Nearest Neighbor Classifier 被引量:8
2
作者 Zhang Yankun & Liu Chongqing Institute of Image Processing and Pattern Recognition, Shanghai Jiao long University, Shanghai 200030 P.R.China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2003年第3期73-76,共4页
Support vector machine (SVM), as a novel approach in pattern recognition, has demonstrated a success in face detection and face recognition. In this paper, a face recognition approach based on the SVM classifier with ... Support vector machine (SVM), as a novel approach in pattern recognition, has demonstrated a success in face detection and face recognition. In this paper, a face recognition approach based on the SVM classifier with the nearest neighbor classifier (NNC) is proposed. The principal component analysis (PCA) is used to reduce the dimension and extract features. Then one-against-all stratedy is used to train the SVM classifiers. At the testing stage, we propose an al- 展开更多
关键词 Face recognition Support vector machine Nearest neighbor classifier Principal component analysis.
在线阅读 下载PDF
Real and Altered Fingerprint Classification Based on Various Features and Classifiers 被引量:1
3
作者 Saif Saad Hameed Ismail Taha Ahmed Omar Munthir Al Okashi 《Computers, Materials & Continua》 SCIE EI 2023年第1期327-340,共14页
Biometric recognition refers to the identification of individuals through their unique behavioral features(e.g.,fingerprint,face,and iris).We need distinguishing characteristics to identify people,such as fingerprints... Biometric recognition refers to the identification of individuals through their unique behavioral features(e.g.,fingerprint,face,and iris).We need distinguishing characteristics to identify people,such as fingerprints,which are world-renowned as the most reliablemethod to identify people.The recognition of fingerprints has become a standard procedure in forensics,and different techniques are available for this purpose.Most current techniques lack interest in image enhancement and rely on high-dimensional features to generate classification models.Therefore,we proposed an effective fingerprint classification method for classifying the fingerprint image as authentic or altered since criminals and hackers routinely change their fingerprints to generate fake ones.In order to improve fingerprint classification accuracy,our proposed method used the most effective texture features and classifiers.Discriminant Analysis(DCA)and Gaussian Discriminant Analysis(GDA)are employed as classifiers,along with Histogram of Oriented Gradient(HOG)and Segmentation-based Feature Texture Analysis(SFTA)feature vectors as inputs.The performance of the classifiers is determined by assessing a range of feature sets,and the most accurate results are obtained.The proposed method is tested using a Sokoto Coventry Fingerprint Dataset(SOCOFing).The SOCOFing project includes 6,000 fingerprint images collected from 600 African people whose fingerprints were taken ten times.Three distinct degrees of obliteration,central rotation,and z-cut have been performed to obtain synthetically altered replicas of the genuine fingerprints.The proposal achieved massive success with a classification accuracy reaching 99%.The experimental results indicate that the proposed method for fingerprint classification is feasible and effective.The experiments also showed that the proposed SFTA-based GDA method outperformed state-of-art approaches in feature dimension and classification accuracy. 展开更多
关键词 Fingerprint classification HOG SFTA discriminant analysis(DCA)classifier gaussian discriminant analysis(gda)classifier SOCOFing
在线阅读 下载PDF
Construction of Influenza Early Warning Model Based on Combinatorial Judgment Classifier:A Case Study of Seasonal Influenza in Hong Kong 被引量:3
4
作者 Zi-xiao WANG James NTAMBARA +3 位作者 Yan LU Wei DAI Rui-jun MENG Dan-min QIAN 《Current Medical Science》 SCIE CAS 2022年第1期226-236,共11页
Objective:The annual influenza epidemic is a heavy burden on the health care system,and has increasingly become a major public health problem in some areas,such as Hong Kong(China).Therefore,based on a variety of mach... Objective:The annual influenza epidemic is a heavy burden on the health care system,and has increasingly become a major public health problem in some areas,such as Hong Kong(China).Therefore,based on a variety of machine learning methods,and considering the seasonal influenza in Hong Kong,the study aims to establish a Combinatorial Judgment Classifier(CJC)model to classify the epidemic trend and improve the accuracy of influenza epidemic early warning. 展开更多
关键词 influenza prediction DATA-DRIVEN Support Vector Machine Discriminant analysis Ensemble classifier
在线阅读 下载PDF
Construction of unsupervised sentiment classifier on idioms resources 被引量:2
5
作者 谢松县 王挺 《Journal of Central South University》 SCIE EI CAS 2014年第4期1376-1384,共9页
Sentiment analysis is the computational study of how opinions, attitudes, emotions, and perspectives are expressed in language, and has been the important task of natural language processing. Sentiment analysis is hig... Sentiment analysis is the computational study of how opinions, attitudes, emotions, and perspectives are expressed in language, and has been the important task of natural language processing. Sentiment analysis is highly valuable for both research and practical applications. The focuses were put on the difficulties in the construction of sentiment classifiers which normally need tremendous labeled domain training data, and a novel unsupervised framework was proposed to make use of the Chinese idiom resources to develop a general sentiment classifier. Furthermore, the domain adaption of general sentiment classifier was improved by taking the general classifier as the base of a self-training procedure to get a domain self-training sentiment classifier. To validate the effect of the unsupervised framework, several experiments were carried out on publicly available Chinese online reviews dataset. The experiments show that the proposed framework is effective and achieves encouraging results. Specifically, the general classifier outperforms two baselines(a Na?ve 50% baseline and a cross-domain classifier), and the bootstrapping self-training classifier approximates the upper bound domain-specific classifier with the lowest accuracy of 81.5%, but the performance is more stable and the framework needs no labeled training dataset. 展开更多
关键词 sentiment analysis sentiment classification bootstrapping idioms general classifier domain-specific classifier
在线阅读 下载PDF
Support vector classifier based on principal component analysis
6
作者 Zheng Chunhong Jiao Licheng Li Yongzhao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第1期184-190,共7页
Support vector classifier(SVC)has the superior advantages for small sample learning problems with high dimensions,with especially better generalization ability.However there is some redundancy among the high dimension... Support vector classifier(SVC)has the superior advantages for small sample learning problems with high dimensions,with especially better generalization ability.However there is some redundancy among the high dimensions of the original samples and the main features of the samples may be picked up first to improve the performance of SVC.A principal component analysis(PCA)is employed to reduce the feature dimensions of the original samples and the pre-selected main features efficiently,and an SVC is constructed in the selected feature space to improve the learning speed and identification rate of SVC.Furthermore,a heuristic genetic algorithm-based automatic model selection is proposed to determine the hyperparameters of SVC to evaluate the performance of the learning machines.Experiments performed on the Heart and Adult benchmark data sets demonstrate that the proposed PCA-based SVC not only reduces the test time drastically,but also improves the identify rates effectively. 展开更多
关键词 support vector classifier principal component analysis feature selection genetic algorithms
在线阅读 下载PDF
Face Recognition Combining Eigen Features with a Parzen Classifier 被引量:1
7
作者 孙鑫 刘兵 刘本永 《Journal of Electronic Science and Technology of China》 2005年第1期18-21,共4页
A face recognition scheme is proposed, wherein a face image is preprocessed by pixel averaging and energy normalizing to reduce data dimension and brightness variation effect, followed by the Fourier transform to esti... A face recognition scheme is proposed, wherein a face image is preprocessed by pixel averaging and energy normalizing to reduce data dimension and brightness variation effect, followed by the Fourier transform to estimate the spectrum of the preprocessed image. The principal component analysis is conducted on the spectra of a face image to obtain eigen features. Combining eigen features with a Parzen classifier, experiments are taken on the ORL face database. 展开更多
关键词 face recognition Fourier transform principal component analysis Parzen classifier pixel averaging energy normalizing
在线阅读 下载PDF
A NOVEL METHOD FOR NETWORK WORM DETECTION BASED ON WAVELET PACKET ANALYSIS
8
作者 廖明涛 张德运 侯琳 《Journal of Pharmaceutical Analysis》 SCIE CAS 2006年第2期97-101,共5页
Objective To detect unknown network worm at its early propagation stage. Methods On the basis of characteristics of network worm attack, the concept of failed connection flow (FCT) was defined. Based on wavelet packet... Objective To detect unknown network worm at its early propagation stage. Methods On the basis of characteristics of network worm attack, the concept of failed connection flow (FCT) was defined. Based on wavelet packet analysis of FCT time series, this method computed the energy associated with each wavelet packet of FCT time series, transformed the FCT time series into a series of energy distribution vector on frequency domain, then a trained K-nearest neighbor (KNN) classifier was applied to identify the worm. Results The experiment showed that the method could identify network worm when the worm started to scan. Compared to theoretic value, the identification error ratio was 5.69%. Conclusion The method can detect unknown network worm at its early propagation stage effectively. 展开更多
关键词 worm detection wavelet packet analysis K-nearest neighbor classifier
在线阅读 下载PDF
Exploiting multi-context analysis in semantic image classification
9
作者 田永鸿 黄铁军 高文 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第11期1268-1283,共16页
As the popularity of digital images is rapidly increasing on the Internet, research on technologies for semantic image classification has become an important research topic. However, the well-known content-based image... As the popularity of digital images is rapidly increasing on the Internet, research on technologies for semantic image classification has become an important research topic. However, the well-known content-based image classification methods do not overcome the so-called semantic gap problem in which low-level visual features cannot represent the high-level semantic content of images. Image classification using visual and textual information often performs poorly since the extracted textual features are often too limited to accurately represent the images. In this paper, we propose a semantic image classification ap- proach using multi-context analysis. For a given image, we model the relevant textual information as its multi-modal context, and regard the related images connected by hyperlinks as its link context. Two kinds of context analysis models, i.e., cross-modal correlation analysis and link-based correlation model, are used to capture the correlation among different modals of features and the topical dependency among images induced by the link structure. We propose a new collective classification model called relational support vector classifier (RSVC) based on the well-known Support Vector Machines (SVMs) and the link-based cor- relation model. Experiments showed that the proposed approach significantly improved classification accuracy over that of SVM classifiers using visual and/or textual features. 展开更多
关键词 Image classification Multi-context analysis Cross-modal correlation analysis Link-based correlation model Linkage semantic kernels Relational support vector classifier
在线阅读 下载PDF
A computer aided detection framework for mammographic images using fisher linear discriminant and nearest neighbor classifier
10
作者 Memuna Sarfraz Fadi Abu-Amara Ikhlas Abdel-Qader 《Journal of Biomedical Science and Engineering》 2012年第6期323-329,共7页
Today, mammography is the best method for early detection of breast cancer. Radiologists failed to detect evident cancerous signs in approximately 20% of false negative mammograms. False negatives have been identified... Today, mammography is the best method for early detection of breast cancer. Radiologists failed to detect evident cancerous signs in approximately 20% of false negative mammograms. False negatives have been identified as the inability of the radiologist to detect the abnormalities due to several reasons such as poor image quality, image noise, or eye fatigue. This paper presents a framework for a computer aided detection system that integrates Principal Component Analysis (PCA), Fisher Linear Discriminant (FLD), and Nearest Neighbor Classifier (KNN) algorithms for the detection of abnormalities in mammograms. Using normal and abnormal mammograms from the MIAS database, the integrated algorithm achieved 93.06% classification accuracy. Also in this paper, we present an analysis of the integrated algorithm’s parameters and suggest selection criteria. 展开更多
关键词 Principal COMPONENT analysis FISHER Linear DISCRIMINANT Nearest NEIGHBOR classifier
在线阅读 下载PDF
A Learning Model to Detect Android C&C Applications Using Hybrid Analysis
11
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
在线阅读 下载PDF
Artificial Intelligence Based Sentence Level Sentiment Analysis of COVID-19
12
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
在线阅读 下载PDF
DM-L Based Feature Extraction and Classifier Ensemble for Object Recognition
13
作者 Hamayun A. Khan 《Journal of Signal and Information Processing》 2018年第2期92-110,共19页
Deep Learning is a powerful technique that is widely applied to Image Recognition and Natural Language Processing tasks amongst many other tasks. In this work, we propose an efficient technique to utilize pre-trained ... Deep Learning is a powerful technique that is widely applied to Image Recognition and Natural Language Processing tasks amongst many other tasks. In this work, we propose an efficient technique to utilize pre-trained Convolutional Neural Network (CNN) architectures to extract powerful features from images for object recognition purposes. We have built on the existing concept of extending the learning from pre-trained CNNs to new databases through activations by proposing to consider multiple deep layers. We have exploited the progressive learning that happens at the various intermediate layers of the CNNs to construct Deep Multi-Layer (DM-L) based Feature Extraction vectors to achieve excellent object recognition performance. Two popular pre-trained CNN architecture models i.e. the VGG_16 and VGG_19 have been used in this work to extract the feature sets from 3 deep fully connected multiple layers namely “fc6”, “fc7” and “fc8” from inside the models for object recognition purposes. Using the Principal Component Analysis (PCA) technique, the Dimensionality of the DM-L feature vectors has been reduced to form powerful feature vectors that have been fed to an external Classifier Ensemble for classification instead of the Softmax based classification layers of the two original pre-trained CNN models. The proposed DM-L technique has been applied to the Benchmark Caltech-101 object recognition database. Conventional wisdom may suggest that feature extractions based on the deepest layer i.e. “fc8” compared to “fc6” will result in the best recognition performance but our results have proved it otherwise for the two considered models. Our experiments have revealed that for the two models under consideration, the “fc6” based feature vectors have achieved the best recognition performance. State-of-the-Art recognition performances of 91.17% and 91.35% have been achieved by utilizing the “fc6” based feature vectors for the VGG_16 and VGG_19 models respectively. The recognition performance has been achieved by considering 30 sample images per class whereas the proposed system is capable of achieving improved performance by considering all sample images per class. Our research shows that for feature extraction based on CNNs, multiple layers should be considered and then the best layer can be selected that maximizes the recognition performance. 展开更多
关键词 DEEP Learning Object Recognition CNN DEEP MULTI-LAYER Feature Extraction Principal Component analysis classifier ENSEMBLE Caltech-101 BENCHMARK Database
在线阅读 下载PDF
Fine-Tuning Cyber Security Defenses: Evaluating Supervised Machine Learning Classifiers for Windows Malware Detection
14
作者 Islam Zada Mohammed Naif Alatawi +4 位作者 Syed Muhammad Saqlain Abdullah Alshahrani Adel Alshamran Kanwal Imran Hessa Alfraihi 《Computers, Materials & Continua》 SCIE EI 2024年第8期2917-2939,共23页
Malware attacks on Windows machines pose significant cybersecurity threats,necessitating effective detection and prevention mechanisms.Supervised machine learning classifiers have emerged as promising tools for malwar... Malware attacks on Windows machines pose significant cybersecurity threats,necessitating effective detection and prevention mechanisms.Supervised machine learning classifiers have emerged as promising tools for malware detection.However,there remains a need for comprehensive studies that compare the performance of different classifiers specifically for Windows malware detection.Addressing this gap can provide valuable insights for enhancing cybersecurity strategies.While numerous studies have explored malware detection using machine learning techniques,there is a lack of systematic comparison of supervised classifiers for Windows malware detection.Understanding the relative effectiveness of these classifiers can inform the selection of optimal detection methods and improve overall security measures.This study aims to bridge the research gap by conducting a comparative analysis of supervised machine learning classifiers for detecting malware on Windows systems.The objectives include Investigating the performance of various classifiers,such as Gaussian Naïve Bayes,K Nearest Neighbors(KNN),Stochastic Gradient Descent Classifier(SGDC),and Decision Tree,in detecting Windows malware.Evaluating the accuracy,efficiency,and suitability of each classifier for real-world malware detection scenarios.Identifying the strengths and limitations of different classifiers to provide insights for cybersecurity practitioners and researchers.Offering recommendations for selecting the most effective classifier for Windows malware detection based on empirical evidence.The study employs a structured methodology consisting of several phases:exploratory data analysis,data preprocessing,model training,and evaluation.Exploratory data analysis involves understanding the dataset’s characteristics and identifying preprocessing requirements.Data preprocessing includes cleaning,feature encoding,dimensionality reduction,and optimization to prepare the data for training.Model training utilizes various supervised classifiers,and their performance is evaluated using metrics such as accuracy,precision,recall,and F1 score.The study’s outcomes comprise a comparative analysis of supervised machine learning classifiers for Windows malware detection.Results reveal the effectiveness and efficiency of each classifier in detecting different types of malware.Additionally,insights into their strengths and limitations provide practical guidance for enhancing cybersecurity defenses.Overall,this research contributes to advancing malware detection techniques and bolstering the security posture of Windows systems against evolving cyber threats. 展开更多
关键词 Security and privacy challenges in the context of requirements engineering supervisedmachine learning malware detection windows systems comparative analysis Gaussian Naive Bayes K Nearest Neighbors Stochastic Gradient Descent classifier Decision Tree
在线阅读 下载PDF
2003—2023年植物嫁接亲和力研究文献计量分析
15
作者 王玉霞 德吉拉姆 《西藏农业科技》 2025年第2期83-89,共7页
为明确植物嫁接亲和力研究方向的总体进展,以中国知网(CNKI)数据库中的相关文献为数据源,基于文献计量分析方法,对2003—2023年植物嫁接亲和力研究方向的文献进行了系统的统计分析。结果表明:1)在期刊载文分布方面,发表文献5篇及以上的... 为明确植物嫁接亲和力研究方向的总体进展,以中国知网(CNKI)数据库中的相关文献为数据源,基于文献计量分析方法,对2003—2023年植物嫁接亲和力研究方向的文献进行了系统的统计分析。结果表明:1)在期刊载文分布方面,发表文献5篇及以上的期刊有7种,占收集文献总数的28.4%。2)在年份发文量方面,各年份发文量存在较大差异,其中2003年发文量最少,仅为3篇,而2009年发文量最多,达到22篇。3)在第一作者发文量方面,绝大部分第一作者发文量在3篇及以下,占比94.78%;发文量为4篇的作者有2人,占比3.21%;仅有1名作者的发文量超过5篇,占比2.01%。4)在文献作者隶属机构方面,高校和科研院所是主要的作者发文机构,在所搜集的250篇文献中,有10个机构在此期间发表的论文数量在4篇以上,占比达31.2%,其中,园艺领域的研究最为集中,论文数量达到209篇,占比83.6%。研究指出,植物嫁接亲和力研究主要集中在园艺、林业及植物保护等领域,不同领域的植物嫁接亲和力受不同因素的影响,因此,需要筛选合适的指标进行深入分析。 展开更多
关键词 植物嫁接亲和力 文献分析 分类统计 文献计量学
在线阅读 下载PDF
基于语音与行为数据分析的体质健康监测可穿戴设备研究
16
作者 王导利 《自动化与仪器仪表》 2025年第9期265-269,共5页
针对传统可穿戴设备语音交互质量低,导致语音与行为数据分析效果不佳的问题,提出设计一个基于SONET-SVM的语音与行为数据分析方法。首先,构建一个体质健康监测系统,并采用SONET模型进行语音增强;然后采用压力采集鞋垫采集监测对象的行... 针对传统可穿戴设备语音交互质量低,导致语音与行为数据分析效果不佳的问题,提出设计一个基于SONET-SVM的语音与行为数据分析方法。首先,构建一个体质健康监测系统,并采用SONET模型进行语音增强;然后采用压力采集鞋垫采集监测对象的行为数据;最后将该行为数据输入至支持向量机(SVM)中,通过其实现足底关键点位特征分类和行为特征分析。结果表明,基于SONET的语音增强算法的语音识别准确率为98.73%,本算法的准确率比传统的DSB、FSB和MVDR波束形成算法分别高了13.94%、10.55%和6.51%。SVM分类模型的步态行为数据分类准确率为99.52%,均高于KNN、CNN分类模型。由此证明,将基于SONET-SVM的语音与行为数据分析方法应用于可穿戴设备后,可实现监测对象体质健康准确监测,具备实用性和有效性。 展开更多
关键词 语音识别 行为数据分析 体质健康监测 可穿戴设备 SVM分类器
原文传递
基于离散度分析的Top-k组合Skyline查询算法
17
作者 董雷刚 刘国华 +1 位作者 王鑫 崔晓微 《计算机应用与软件》 北大核心 2025年第2期72-80,共9页
现有的组合Skyline查询算法不能区分组合中数据的离散度,且输出结果集很大。针对这种情况,提出基于数据离散度分析的Top-k组合Skyline查询算法。提出基于权重的组合离散系数概念及其计算方法;设置分类器将组合划分至不同的组合队列;采... 现有的组合Skyline查询算法不能区分组合中数据的离散度,且输出结果集很大。针对这种情况,提出基于数据离散度分析的Top-k组合Skyline查询算法。提出基于权重的组合离散系数概念及其计算方法;设置分类器将组合划分至不同的组合队列;采用并行处理方式对各组合队列进行计算。实验结果表明,该算法可以根据用户自定义条件准确有效地返回结果,能满足实际应用的需要。 展开更多
关键词 组合Skyline 离散度分析 TOP-K 离散系数 分类器 并行处理
在线阅读 下载PDF
基于模糊规则二元分类器组合的农林物种光谱开集分类识别研究
18
作者 何保雄 赵鹏 李振宇 《光谱学与光谱分析》 北大核心 2025年第12期3349-3357,共9页
开集分类识别要求分类器不仅能够“辨识”已知类别的测试样本,而且还要有效地“拒识”未知类别的测试样本;在光谱分析中有关的研究与应用相对较少。改进了Ishibuchi提出的经典的闭集框架下的模糊规则多类别分类器,将其应用于开集分类识... 开集分类识别要求分类器不仅能够“辨识”已知类别的测试样本,而且还要有效地“拒识”未知类别的测试样本;在光谱分析中有关的研究与应用相对较少。改进了Ishibuchi提出的经典的闭集框架下的模糊规则多类别分类器,将其应用于开集分类识别领域。首先,使用主成分分析法进行原始光谱曲线向量的光谱维度约简,降维至4维~6维的光谱特征向量。其次,将Ishibuchi提出的模糊规则多类别分类器简化为二元分类器版本,采用1-vs-1二元分类器进行分类处理,并且确定该测试样本在相应类别的得票。最后,将所有二元分类器的投票数进行统计,如果某个已知类别的得票数最高,并且该最高得票数大于预先确定的阈值τ,那么测试样本判决为该已知类别;否则就“拒识”为未知类别,从而实现了多类别的开集分类识别。在实验验证中,对于木材和芒果光谱数据集进行了分组的对比实验,结果表明,本方法优于其他的主流的开集分类识别,包括基于广义基本概率分配(generalized Basic probability assignment,GBPA)的改进的开集框架下的模糊规则多类别分类器;具有最好的评价指标F-Score,Kappa系数及总体识别率。此外,还针对芒果光谱数据集的对比实验进行了双尾McNemar s Test统计检验,进一步表明该方法相对于其他的开集分类识别方法来说,具有统计检验意义的优势。 展开更多
关键词 开集分类识别 模糊规则分类器 二元分类器 光谱分析 统计检验
在线阅读 下载PDF
Investigations on Multiclass Classification Model-Based Optimized Weights Spectrum for Rotating Machinery Condition Monitoring
19
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
在线阅读 下载PDF
Implementation of an AI-based predictive structural health monitoring strategy for bonded insulated rail joints using digital twins under varied bolt conditions
20
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
在线阅读 下载PDF
上一页 1 2 39 下一页 到第
使用帮助 返回顶部