期刊文献+
共找到9,698篇文章
< 1 2 250 >
每页显示 20 50 100
Structural Topology Design for Electromagnetic Performance Enhancement of Permanent-Magnet Machines 被引量:2
1
作者 Pengjie Xiang Liang Yan +3 位作者 Xiaoshuai Liu Xinghua He Nannan Du Han Wang 《Chinese Journal of Mechanical Engineering》 2025年第1期411-432,共22页
Permanent-magnet(PM)machines are the important driving components of various mechanical equipment and industrial applications,such as robot joints,aerospace equipment,electric vehicles,actuators,wind generators and el... Permanent-magnet(PM)machines are the important driving components of various mechanical equipment and industrial applications,such as robot joints,aerospace equipment,electric vehicles,actuators,wind generators and electric traction systems.The PM machines are usually expected to have high torque/power density,low torque ripple,reduced rotor mass,a large constant power speed range or strong anti-magnetization capability to match different requirements of industrial applications.The structural topology of the electric machines,including stator/rotor arrangements and magnet patterns of rotor,is one major concern to improve their electromagnetic performance.However,systematic reviews of structural topology are seldom found in literature.Therefore,the objective of this paper is to summarize the stator/rotor arrangements and magnet patterns of the permanent-magnet brushless machines,in depth.Specifically,the stator/rotor arrangements of the PM machines including radial-flux,axialflux and emerging hybrid axial-radial flux configurations are presented,and pros and cons of these topologies are discussed regarding their electromagnetic performance.The magnet patterns including various surface-mounted and interior magnet patterns,such as parallel magnetization pole pattern,Halbach arrays,spoke-type designs and their variants are summarized,and the characteristics of those magnet patterns in terms of flux-focusing effect,magnetic self-shielding effect,torque ripple,reluctance torque,magnet utilization ratio,and anti-demagnetization capability are compared.This paper can provide guidance and suggestion for the structure selection and design of PM brushless machines for high-performance industrial applications. 展开更多
关键词 Actuators Robot joint Electric-vehicle motor Permanent-magnet machines Axial-flux PM machine Dualrotor machine Magnet patterns Torque density Torque ripple Power density
在线阅读 下载PDF
An Adaptive Cooperated Shuffled Frog-Leaping Algorithm for Parallel Batch Processing Machines Scheduling in Fabric Dyeing Processes
2
作者 Lianqiang Wu Deming Lei Yutong Cai 《Computers, Materials & Continua》 2025年第5期1771-1789,共19页
Fabric dyeing is a critical production process in the clothing industry and heavily relies on batch processing machines(BPM).In this study,the parallel BPM scheduling problem with machine eligibility in fabric dyeing ... Fabric dyeing is a critical production process in the clothing industry and heavily relies on batch processing machines(BPM).In this study,the parallel BPM scheduling problem with machine eligibility in fabric dyeing is considered,and an adaptive cooperated shuffled frog-leaping algorithm(ACSFLA)is proposed to minimize makespan and total tardiness simultaneously.ACSFLA determines the search times for each memeplex based on its quality,with more searches in high-quality memeplexes.An adaptive cooperated and diversified search mechanism is applied,dynamically adjusting search strategies for each memeplex based on their dominance relationships and quality.During the cooperated search,ACSFLA uses a segmented and dynamic targeted search approach,while in non-cooperated scenarios,the search focuses on local search around superior solutions to improve efficiency.Furthermore,ACSFLA employs adaptive population division and partial population shuffling strategies.Through these strategies,memeplexes with low evolutionary potential are selected for reconstruction in the next generation,while thosewithhighevolutionarypotential are retained to continue their evolution.Toevaluate the performance of ACSFLA,comparative experiments were conducted using ACSFLA,SFLA,ASFLA,MOABC,and NSGA-CC in 90 instances.The computational results reveal that ACSFLA outperforms the other algorithms in 78 of the 90 test cases,highlighting its advantages in solving the parallel BPM scheduling problem with machine eligibility. 展开更多
关键词 Batch processing machine parallel machine scheduling shuffled frog-leaping algorithm fabric dyeing process machine eligibility
在线阅读 下载PDF
LEADSFON-PILOTELLI:The high-speed single jersey open width machine shows up
3
《China Textile》 2025年第5期55-55,共1页
LEADSFON(XIAMEN)TEXTILE TECH CO.,LTD.is a manufacturer of knitting circular machines.Since 2002,the company has served as an ODM and supporting partner for the Italian brand"PILOTELLI".In 2014,LEADSFON offic... LEADSFON(XIAMEN)TEXTILE TECH CO.,LTD.is a manufacturer of knitting circular machines.Since 2002,the company has served as an ODM and supporting partner for the Italian brand"PILOTELLI".In 2014,LEADSFON officially acquired PILOTELLI,integrating advanced Italian technology into its core operations. 展开更多
关键词 advanced italian technology high speed single jersey machine Pilotelli advanced Italian technology knitting circular machines ODM knitting circular machinessince odm supporting partner
在线阅读 下载PDF
Machine learning of pyrite geochemistry reconstructs the multi-stage history of mineral deposits 被引量:1
4
作者 Pengpeng Yu Yuan Liu +5 位作者 Hanyu Wang Xi Chen Yi Zheng Wei Cao Yiqu Xiong Hongxiang Shan 《Geoscience Frontiers》 2025年第3期81-93,共13页
The application of machine learning for pyrite discrimination establishes a robust foundation for constructing the ore-forming history of multi-stage deposits;however,published models face challenges related to limite... The application of machine learning for pyrite discrimination establishes a robust foundation for constructing the ore-forming history of multi-stage deposits;however,published models face challenges related to limited,imbalanced datasets and oversampling.In this study,the dataset was expanded to approximately 500 samples for each type,including 508 sedimentary,573 orogenic gold,548 sedimentary exhalative(SEDEX)deposits,and 364 volcanogenic massive sulfides(VMS)pyrites,utilizing random forest(RF)and support vector machine(SVM)methodologies to enhance the reliability of the classifier models.The RF classifier achieved an overall accuracy of 99.8%,and the SVM classifier attained an overall accuracy of 100%.The model was evaluated by a five-fold cross-validation approach with 93.8%accuracy for the RF and 94.9%for the SVM classifier.These results demonstrate the strong feasibility of pyrite classification,supported by a relatively large,balanced dataset and high accuracy rates.The classifier was employed to reveal the genesis of the controversial Keketale Pb-Zn deposit in NW China,which has been inconclusive among SEDEX,VMS,or a SEDEX-VMS transition.Petrographic investigations indicated that the deposit comprises early fine-grained layered pyrite(Py1)and late recrystallized pyrite(Py2).The majority voting classified Py1 as the VMS type,with an accuracy of RF and SVM being 72.2%and 75%,respectively,and confirmed Py2 as an orogenic type with 74.3% and 77.1%accuracy,respectively.The new findings indicated that the Keketale deposit originated from a submarine VMS mineralization system,followed by late orogenic-type overprinting of metamorphism and deformation,which is consistent with the geological and geochemical observations.This study further emphasizes the advantages of Machine learning(ML)methods in accurately and directly discriminating the deposit types and reconstructing the formation history of multi-stage deposits. 展开更多
关键词 machine learning Random forest Support vector machine PYRITE Multi-stage genesis Keketale deposit
在线阅读 下载PDF
Machine Learning Techniques in Predicting Hot Deformation Behavior of Metallic Materials
5
作者 Petr Opela Josef Walek Jaromír Kopecek 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期713-732,共20页
In engineering practice,it is often necessary to determine functional relationships between dependent and independent variables.These relationships can be highly nonlinear,and classical regression approaches cannot al... In engineering practice,it is often necessary to determine functional relationships between dependent and independent variables.These relationships can be highly nonlinear,and classical regression approaches cannot always provide sufficiently reliable solutions.Nevertheless,Machine Learning(ML)techniques,which offer advanced regression tools to address complicated engineering issues,have been developed and widely explored.This study investigates the selected ML techniques to evaluate their suitability for application in the hot deformation behavior of metallic materials.The ML-based regression methods of Artificial Neural Networks(ANNs),Support Vector Machine(SVM),Decision Tree Regression(DTR),and Gaussian Process Regression(GPR)are applied to mathematically describe hot flow stress curve datasets acquired experimentally for a medium-carbon steel.Although the GPR method has not been used for such a regression task before,the results showed that its performance is the most favorable and practically unrivaled;neither the ANN method nor the other studied ML techniques provide such precise results of the solved regression analysis. 展开更多
关键词 machine learning Gaussian process regression artificial neural networks support vector machine hot deformation behavior
在线阅读 下载PDF
Utilizing Machine Learning and SHAP Values for Improved and Transparent Energy Usage Predictions
6
作者 Faisal Ghazi Beshaw Thamir Hassan Atyia +2 位作者 Mohd Fadzli Mohd Salleh Mohamad Khairi Ishak Abdul Sattar Din 《Computers, Materials & Continua》 2025年第5期3553-3583,共31页
The significance of precise energy usage forecasts has been highlighted by the increasing need for sustainability and energy efficiency across a range of industries.In order to improve the precision and openness of en... The significance of precise energy usage forecasts has been highlighted by the increasing need for sustainability and energy efficiency across a range of industries.In order to improve the precision and openness of energy consumption projections,this study investigates the combination of machine learning(ML)methods with Shapley additive explanations(SHAP)values.The study evaluates three distinct models:the first is a Linear Regressor,the second is a Support Vector Regressor,and the third is a Decision Tree Regressor,which was scaled up to a Random Forest Regressor/Additions made were the third one which was Regressor which was extended to a Random Forest Regressor.These models were deployed with the use of Shareable,Plot-interpretable Explainable Artificial Intelligence techniques,to improve trust in the AI.The findings suggest that our developedmodels are superior to the conventional models discussed in prior studies;with high Mean Absolute Error(MAE)and Root Mean Squared Error(RMSE)values being close to perfection.In detail,the Random Forest Regressor shows the MAE of 0.001 for predicting the house prices whereas the SVR gives 0.21 of MAE and 0.24 RMSE.Such outcomes reflect the possibility of optimizing the use of the promoted advanced AI models with the use of Explainable AI for more accurate prediction of energy consumption and at the same time for the models’decision-making procedures’explanation.In addition to increasing prediction accuracy,this strategy gives stakeholders comprehensible insights,which facilitates improved decision-making and fosters confidence in AI-powered energy solutions.The outcomes show how well ML and SHAP work together to enhance prediction performance and guarantee transparency in energy usage projections. 展开更多
关键词 Renewable energy consumption machine learning explainable AI random forest support vector machine decision trees forecasting energy modeling
在线阅读 下载PDF
Optimizing liver utilization for transplantation with partial grafts undergoing normothermic machine perfusion:Two case reports
7
作者 Maria Baimas-George William H Archie +8 位作者 Kyle Soltys Jose R Soto David Levi Lon Eskind Vincent Casingal Roger Denny Magdy Attia George V Mazariegos Dionisios Vrochides 《World Journal of Transplantation》 2025年第3期263-272,共10页
BACKGROUND Liver transplantation(LT)is the only curative,life-saving option for children and adults with end-stage liver disease.Due to the well-known shortage and heterogeneity of grafts,split LT(SLT)is an attractive... BACKGROUND Liver transplantation(LT)is the only curative,life-saving option for children and adults with end-stage liver disease.Due to the well-known shortage and heterogeneity of grafts,split LT(SLT)is an attractive strategy to expand the donor pool and reduce waitlist times.Given increased risk of cold ischemia time with SLT,machine perfusion represents a promising option to reduce it and optimize transplant logistics and outcomes.The present communication describes various possible combinations of procurement steps to perform SLT facilitated by placing one or both grafts on a normothermic machine perfusion(NMP)closed circuit device.CASE SUMMARY A 19-month-old female with biliary atresia after failed Kasai portoenterostomy and a 42-year-old woman with unresectable intrahepatic cholangiocarcinoma were selected as recipients for a SLT from a 17-year-old male donor.The SLT generated a left lateral segment and a right trisectional graft of appropriate volume for both recipients.After a mixed in-situ and ex-situ split,in order to improve logistics,the right trisectional graft was placed on a closed circuit NMP device,following an appropriate vascular reconstruction.Both grafts were implanted with excellent short-term outcomes.CONCLUSION Use of NMP with SLT for preservation prior to implantation allows not only for graft optimization but also for significant improvement of transplant logistics.We propose various models and standardization of logistic options for combining SLT with NMP to optimize graft availability and outcomes. 展开更多
关键词 Liver transplantation Normothermic machine perfusion Hypothermic machine perfusion Split liver transplantation Left lateral section Right trisectional graft PRESERVATION LOGISTICS Standardization Case report
暂未订购
Machine learning-based models for prediction of in-hospital mortality in patients with dengue shock syndrome
8
作者 Luan Thanh Vo Thien Vu +2 位作者 Thach Ngoc Pham Tung Huu Trinh Thanh Tat Nguyen 《World Journal of Methodology》 2025年第3期89-99,共11页
BACKGROUND Severe dengue children with critical complications have been attributed to high mortality rates,varying from approximately 1%to over 20%.To date,there is a lack of data on machine-learning-based algorithms ... BACKGROUND Severe dengue children with critical complications have been attributed to high mortality rates,varying from approximately 1%to over 20%.To date,there is a lack of data on machine-learning-based algorithms for predicting the risk of inhospital mortality in children with dengue shock syndrome(DSS).AIM To develop machine-learning models to estimate the risk of death in hospitalized children with DSS.METHODS This single-center retrospective study was conducted at tertiary Children’s Hospital No.2 in Viet Nam,between 2013 and 2022.The primary outcome was the in-hospital mortality rate in children with DSS admitted to the pediatric intensive care unit(PICU).Nine significant features were predetermined for further analysis using machine learning models.An oversampling method was used to enhance the model performance.Supervised models,including logistic regression,Naïve Bayes,Random Forest(RF),K-nearest neighbors,Decision Tree and Extreme Gradient Boosting(XGBoost),were employed to develop predictive models.The Shapley Additive Explanation was used to determine the degree of contribution of the features.RESULTS In total,1278 PICU-admitted children with complete data were included in the analysis.The median patient age was 8.1 years(interquartile range:5.4-10.7).Thirty-nine patients(3%)died.The RF and XGboost models demonstrated the highest performance.The Shapley Addictive Explanations model revealed that the most important predictive features included younger age,female patients,presence of underlying diseases,severe transaminitis,severe bleeding,low platelet counts requiring platelet transfusion,elevated levels of international normalized ratio,blood lactate and serum creatinine,large volume of resuscitation fluid and a high vasoactive inotropic score(>30).CONCLUSION We developed robust machine learning-based models to estimate the risk of death in hospitalized children with DSS.The study findings are applicable to the design of management schemes to enhance survival outcomes of patients with DSS. 展开更多
关键词 Dengue shock syndrome Dengue mortality machine learning Supervised models Logistic regression Random forest K-nearest neighbors Support vector machine Extreme Gradient Boost Shapley addictive explanations
暂未订购
Enhancing Classification Algorithm Recommendation in Automated Machine Learning: A Meta-Learning Approach Using Multivariate Sparse Group Lasso
9
作者 Irfan Khan Xianchao Zhang +2 位作者 Ramesh Kumar Ayyasamy Saadat M.Alhashmi Azizur Rahim 《Computer Modeling in Engineering & Sciences》 2025年第2期1611-1636,共26页
The rapid growth of machine learning(ML)across fields has intensified the challenge of selecting the right algorithm for specific tasks,known as the Algorithm Selection Problem(ASP).Traditional trial-and-error methods... The rapid growth of machine learning(ML)across fields has intensified the challenge of selecting the right algorithm for specific tasks,known as the Algorithm Selection Problem(ASP).Traditional trial-and-error methods have become impractical due to their resource demands.Automated Machine Learning(AutoML)systems automate this process,but often neglect the group structures and sparsity in meta-features,leading to inefficiencies in algorithm recommendations for classification tasks.This paper proposes a meta-learning approach using Multivariate Sparse Group Lasso(MSGL)to address these limitations.Our method models both within-group and across-group sparsity among meta-features to manage high-dimensional data and reduce multicollinearity across eight meta-feature groups.The Fast Iterative Shrinkage-Thresholding Algorithm(FISTA)with adaptive restart efficiently solves the non-smooth optimization problem.Empirical validation on 145 classification datasets with 17 classification algorithms shows that our meta-learning method outperforms four state-of-the-art approaches,achieving 77.18%classification accuracy,86.07%recommendation accuracy and 88.83%normalized discounted cumulative gain. 展开更多
关键词 META-LEARNING machine learning automated machine learning classification meta-features
在线阅读 下载PDF
Advances in high-pressure materials discovery enabled by machine learning
10
作者 Zhenyu Wang Xiaoshan Luo +5 位作者 Qingchang Wang Heng Ge Pengyue Gao Wei Zhang Jian Lv Yanchao Wang 《Matter and Radiation at Extremes》 2025年第3期1-9,共9页
Crystal structure prediction(CSP)is a foundational computational technique for determining the atomic arrangements of crystalline materials,especially under high-pressure conditions.While CSP plays a critical role in ... Crystal structure prediction(CSP)is a foundational computational technique for determining the atomic arrangements of crystalline materials,especially under high-pressure conditions.While CSP plays a critical role in materials science,traditional approaches often encounter significant challenges related to computational efficiency and scalability,particularly when applied to complex systems.Recent advances in machine learning(ML)have shown tremendous promise in addressing these limitations,enabling the rapid and accurate prediction of crystal structures across a wide range of chemical compositions and external conditions.This review provides a concise overview of recent progress in ML-assisted CSP methodologies,with a particular focus on machine learning potentials and generative models.By critically analyzing these advances,we highlight the transformative impact of ML in accelerating materials discovery,enhancing computational efficiency,and broadening the applicability of CSP.Additionally,we discuss emerging opportunities and challenges in this rapidly evolving field. 展开更多
关键词 machine learning crystal structure prediction csp determining atomic arrangements crystalline materialsespecially crystal structure prediction machine learning ml complex systemsrecent high pressure materials discovery
在线阅读 下载PDF
Deep Learning and Machine Learning Architectures for Dementia Detection from Speech in Women
11
作者 Ahlem Walha Amel Ksibi +5 位作者 Mohammed Zakariah Manel Ayadi Tagrid Alshalali Oumaima Saidani Leila Jamel Nouf Abdullah Almujally 《Computer Modeling in Engineering & Sciences》 2025年第3期2959-3001,共43页
Dementia is a neurological disorder that affects the brain and its functioning,and women experience its effects more than men do.Preventive care often requires non-invasive and rapid tests,yet conventional diagnostic ... Dementia is a neurological disorder that affects the brain and its functioning,and women experience its effects more than men do.Preventive care often requires non-invasive and rapid tests,yet conventional diagnostic techniques are time-consuming and invasive.One of the most effective ways to diagnose dementia is by analyzing a patient’s speech,which is cheap and does not require surgery.This research aims to determine the effectiveness of deep learning(DL)and machine learning(ML)structures in diagnosing dementia based on women’s speech patterns.The study analyzes data drawn from the Pitt Corpus,which contains 298 dementia files and 238 control files from the Dementia Bank database.Deep learning models and SVM classifiers were used to analyze the available audio samples in the dataset.Our methodology used two methods:a DL-ML model and a single DL model for the classification of diabetics and a single DL model.The deep learning model achieved an astronomic level of accuracy of 99.99%with an F1 score of 0.9998,Precision of 0.9997,and recall of 0.9998.The proposed DL-ML fusion model was equally impressive,with an accuracy of 99.99%,F1 score of 0.9995,Precision of 0.9998,and recall of 0.9997.Also,the study reveals how to apply deep learning and machine learning models for dementia detection from speech with high accuracy and low computational complexity.This research work,therefore,concludes by showing the possibility of using speech-based dementia detection as a possibly helpful early diagnosis mode.For even further enhanced model performance and better generalization,future studies may explore real-time applications and the inclusion of other components of speech. 展开更多
关键词 Dementia detection in women Alzheimer’s disease deep learning machine learning support vector machine voting classifier
在线阅读 下载PDF
Carbon dioxide storage and cumulative oil production predictions in unconventional reservoirs applying optimized machine-learning models
12
作者 Shadfar Davoodi Hung Vo Thanh +3 位作者 David A.Wood Mohammad Mehrad Sergey V.Muravyov Valeriy S.Rukavishnikov 《Petroleum Science》 2025年第1期296-323,共28页
To achieve carbon dioxide(CO_(2))storage through enhanced oil recovery,accurate forecasting of CO_(2) subsurface storage and cumulative oil production is essential.This study develops hybrid predictive models for the ... To achieve carbon dioxide(CO_(2))storage through enhanced oil recovery,accurate forecasting of CO_(2) subsurface storage and cumulative oil production is essential.This study develops hybrid predictive models for the determination of CO_(2) storage mass and cumulative oil production in unconventional reservoirs.It does so with two multi-layer perceptron neural networks(MLPNN)and a least-squares support vector machine(LSSVM),hybridized with grey wolf optimization(GWO)and/or particle swarm optimization(PSO).Large,simulated datasets were divided into training(70%)and testing(30%)groups,with normalization applied to both groups.Mahalanobis distance identifies/eliminates outliers in the training subset only.A non-dominated sorting genetic algorithm(NSGA-II)combined with LSSVM selected seven influential features from the nine available input parameters:reservoir depth,porosity,permeability,thickness,bottom-hole pressure,area,CO_(2) injection rate,residual oil saturation to gas flooding,and residual oil saturation to water flooding.Predictive models were developed and tested,with performance evaluated with an overfitting index(OFI),scoring analysis,and partial dependence plots(PDP),during training and independent testing to enhance model focus and effectiveness.The LSSVM-GWO model generated the lowest root mean square error(RMSE)values(0.4052 MMT for CO_(2) storage and 9.7392 MMbbl for cumulative oil production)in the training group.That trained model also exhibited excellent generalization and minimal overfitting when applied to the testing group(RMSE of 0.6224 MMT for CO_(2) storage and 12.5143 MMbbl for cumulative oil production).PDP analysis revealed that the input features“area”and“porosity”had the most influence on the LSSVM-GWO model's pre-diction performance.This paper presents a new hybrid modeling approach that achieves accurate forecasting of CO_(2) subsurface storage and cumulative oil production.It also establishes a new standard for such forecasting,which can lead to the development of more effective and sustainable solutions for oil recovery. 展开更多
关键词 Hybrid machine learning Least-squares support vector machine Grey wolf optimization Feature selection Carbon dioxide storage Enhanced oil recovery
原文传递
NJmat 2.0:User Instructions of Data-Driven Machine Learning Interface for Materials Science
13
作者 Lei Zhang Hangyuan Deng 《Computers, Materials & Continua》 2025年第4期1-11,共11页
NJmat is a user-friendly,data-driven machine learning interface designed for materials design and analysis.The platform integrates advanced computational techniques,including natural language processing(NLP),large lan... NJmat is a user-friendly,data-driven machine learning interface designed for materials design and analysis.The platform integrates advanced computational techniques,including natural language processing(NLP),large language models(LLM),machine learning potentials(MLP),and graph neural networks(GNN),to facili-tate materials discovery.The platform has been applied in diverse materials research areas,including perovskite surface design,catalyst discovery,battery materials screening,structural alloy design,and molecular informatics.By automating feature selection,predictive modeling,and result interpretation,NJmat accelerates the development of high-performance materials across energy storage,conversion,and structural applications.Additionally,NJmat serves as an educational tool,allowing students and researchers to apply machine learning techniques in materials science with minimal coding expertise.Through automated feature extraction,genetic algorithms,and interpretable machine learning models,NJmat simplifies the workflow for materials informatics,bridging the gap between AI and experimental materials research.The latest version(available at https://figshare.com/articles/software/NJmatML/24607893(accessed on 01 January 2025))enhances its functionality by incorporating NJmatNLP,a module leveraging language models like MatBERT and those based on Word2Vec to support materials prediction tasks.By utilizing clustering and cosine similarity analysis with UMAP visualization,NJmat enables intuitive exploration of materials datasets.While NJmat primarily focuses on structure-property relationships and the discovery of novel chemistries,it can also assist in optimizing processing conditions when relevant parameters are included in the training data.By providing an accessible,integrated environment for machine learning-driven materials discovery,NJmat aligns with the objectives of the Materials Genome Initiative and promotes broader adoption of AI techniques in materials science. 展开更多
关键词 DATA-DRIVEN machine learning natural language processing machine learning potential large language model
在线阅读 下载PDF
Enhancing Convective Wind Prediction:Two Machine Learning Approach with Multi-Regime Flow Analysis and Adaptive Model Integration
14
作者 ZHANG Hua-long WU Zhi-fang +3 位作者 XIAO Liu-si LUO Cong HAN Pu-cheng HU Rong 《Journal of Tropical Meteorology》 2025年第4期379-395,共17页
This study explores the initiation mechanisms of convective wind events,emphasizing their variability across different atmospheric circulation patterns.Historically,the inadequate feature categorization within multi-f... This study explores the initiation mechanisms of convective wind events,emphasizing their variability across different atmospheric circulation patterns.Historically,the inadequate feature categorization within multi-faceted forecast models has led to suboptimal forecast efficacy,particularly for events in dynamically weak forcing conditions during the warm season.To improve the prediction accuracy of convective wind events,this research introduces a novel approach that combines machine learning techniques to identify varying meteorological flow regimes.Convective winds(CWs)are defined as wind speeds reaching or exceeding 17.2 m s^(-1)and severe convective winds(SCWs)as speeds surpassing 24.5 m s^(-1).This study examines the spatial and temporal distribution of CW and SCW events from 2013 to 2021 and their circulation dynamics associated with three primary flow regimes:cold air advection,warm air advection,and quasibarotropic conditions.Key circulation features are used as input variables to construct an effective weather system pattern recognition model.This model employs an Adaptive Boosting(AdaBoost)algorithm combined with Random Under-Sampling(RUS)to address the class imbalance issue,achieving a recognition accuracy of 90.9%.Furthermore,utilizing factor analysis and Support Vector Machine(SVM)techniques,three specialized and independent probabilistic prediction models are developed based on the variance in predictor distributions across different flow regimes.By integrating the type of identification model with these prediction models,an enhanced comprehensive model is constructed.This advanced model autonomously identifies flow types and accordingly selects the most appropriate prediction model.Over a three-year validation period,this improved model outperformed the initially unclassified model in terms of prediction accuracy.Notably,for CWs and SCWs,the maximum Peirce Skill Score(PSS)increased from 0.530 and 0.702 to 0.628 and 0.726,respectively,and the corresponding maximum Threat Score(TS)improved from 0.087 and 0.024 to 0.120 and 0.026.These improvements were significant across all samples,with the cold air advection type showing the greatest enhancement due to the significant spatial variability of each factor.Additionally,the model improved forecast precision by prioritizing thermal factors,which played a key role in modulating false alarm rates in warm air advection and quasi-barotropic flow regimes.The results confirm the critical contribution of circulation feature recognition and segmented modeling to enhancing the adaptability and predictive accuracy of weather forecast models. 展开更多
关键词 convective winds probabilistic forecast regime flow recognition machine learning support vector machine
在线阅读 下载PDF
Machine vision and learning for evaluating different rancidity grades of Prunus mandshurica(Maxim.)Koehne
15
作者 Yashun Wang Huirong Chen +3 位作者 Jianting Gong Yang Cui Huiqin Zou Yonghong Yan 《Journal of Traditional Chinese Medical Sciences》 2025年第2期287-296,共10页
Objective:To explore a rapid and accurate method for evaluating the quality of Prunus mandshurica(Maxim.)Koehne(P.mandshurica,Ku Xing Ren)during rancidity using machine vision and learning.Methods:Sensory evaluation a... Objective:To explore a rapid and accurate method for evaluating the quality of Prunus mandshurica(Maxim.)Koehne(P.mandshurica,Ku Xing Ren)during rancidity using machine vision and learning.Methods:Sensory evaluation and chemometrics were used to classify P.mandshurica quality grades after rancidity.Chemical indicators of the P.mandshurica quality change were determined to verify the ob-tained grades and support the subsequent modeling.The International Commission on Illumination color space was used to extract the color features of the P.mandshurica.Discrimination and prediction models based on color features combined with multiple machine learning algorithms were established using 10-fold cross-validation and external test set validation.Results:The P.mandshurica rancidity samples were allocated to three quality grades.The Bayes net model based on powder color successfully identified the P.mandshurica at different grades with an accuracy of 88.89%and 100%using two validations,and the naive Bayes model based on section color achieved the same accuracy with an receiver operating characteristic area of 0.979.The instance-based k-nearest neighbors model based on powder color performed best in predicting the amygdalin content[R^(2)=0.9801,mean absolute error(MAE)=0.2071,root mean squared error(RMSE)=0.4170],followed by the random com-mittee model in predicting the acid value(R^(2)=0.9580,MAE=1.5121,RMSE=1.9099)and the random forest model in predicting the peroxide value(R^(2)=0.8857,MAE=0.0027,RMSE=0.0035).Conclusion:This study demonstrates that color digitization analysis is a potential method for rapidly evaluating the quality of P.mandshurica across the rancidity process,providing a new reference for the quality assessment of traditional Chinese medicines. 展开更多
关键词 Quality evaluation Prunus mandshurica(Maxim.)Koehne RANCIDITY machine vision machine learning
在线阅读 下载PDF
Analysing Effectiveness of Sentiments in Social Media Data Using Machine Learning Techniques
16
作者 Thambusamy Velmurugan Mohandas Archana Ajith Singh Nongmaithem 《Journal of Computer and Communications》 2025年第1期136-151,共16页
Every second, a large volume of useful data is created in social media about the various kind of online purchases and in another forms of reviews. Particularly, purchased products review data is enormously growing in ... Every second, a large volume of useful data is created in social media about the various kind of online purchases and in another forms of reviews. Particularly, purchased products review data is enormously growing in different database repositories every day. Most of the review data are useful to new customers for theier further purchases as well as existing companies to view customers feedback about various products. Data Mining and Machine Leaning techniques are familiar to analyse such kind of data to visualise and know the potential use of the purchased items through online. The customers are making quality of products through their sentiments about the purchased items from different online companies. In this research work, it is analysed sentiments of Headphone review data, which is collected from online repositories. For the analysis of Headphone review data, some of the Machine Learning techniques like Support Vector Machines, Naive Bayes, Decision Trees and Random Forest Algorithms and a Hybrid method are applied to find the quality via the customers’ sentiments. The accuracy and performance of the taken algorithms are also analysed based on the three types of sentiments such as positive, negative and neutral. 展开更多
关键词 Support Vector machine Random Forest Algorithm Naive Bayes Algorithm machine Learning Techniques Decision Tree Algorithm
在线阅读 下载PDF
TBM big data preprocessing method in machine learning and its application to tunneling
17
作者 Xinyue Zhang Xiaoping Zhang +3 位作者 Quansheng Liu Weiqiang Xie Shaohui Tang Zengmao Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第8期4762-4783,共22页
The big data generated by tunnel boring machines(TBMs)are widely used to reveal complex rock-machine interactions by machine learning(ML)algorithms.Data preprocessing plays a crucial role in improving ML accuracy.For ... The big data generated by tunnel boring machines(TBMs)are widely used to reveal complex rock-machine interactions by machine learning(ML)algorithms.Data preprocessing plays a crucial role in improving ML accuracy.For this,a TBM big data preprocessing method in ML was proposed in the present study.It emphasized the accurate division of TBM tunneling cycle and the optimization method of feature extraction.Based on the data collected from a TBM water conveyance tunnel in China,its effectiveness was demonstrated by application in predicting TBM performance.Firstly,the Score-Kneedle(S-K)method was proposed to divide a TBM tunneling cycle into five phases.Conducted on 500 TBM tunneling cycles,the S-K method accurately divided all five phases in 458 cycles(accuracy of 91.6%),which is superior to the conventional duration division method(accuracy of 74.2%).Additionally,the S-K method accurately divided the stable phase in 493 cycles(accuracy of 98.6%),which is superior to two state-of-the-art division methods,namely the histogram discriminant method(accuracy of 94.6%)and the cumulative sum change point detection method(accuracy of 92.8%).Secondly,features were extracted from the divided phases.Specifically,TBM tunneling resistances were extracted from the free rotating phase and free advancing phase.The resistances were subtracted from the total forces to represent the true rock-fragmentation forces.The secant slope and the mean value were extracted as features of the increasing phase and stable phase,respectively.Finally,an ML model integrating a deep neural network and genetic algorithm(GA-DNN)was established to learn the preprocessed data.The GA-DNN used 6 secant slope features extracted from the increasing phase to predict the mean field penetration index(FPI)and torque penetration index(TPI)in the stable phase,guiding TBM drivers to make better decisions in advance.The results indicate that the proposed TBM big data preprocessing method can improve prediction accuracy significantly(improving R2s of TPI and FPI on the test dataset from 0.7716 to 0.9178 and from 0.7479 to 0.8842,respectively). 展开更多
关键词 Tunnel boring machine Big data preprocessing Division of tunneling cycle Tunneling resistance machine learning
在线阅读 下载PDF
Intelligent tool setting for vibration cutting process using machine vision and hearing
18
作者 Zhihao Ma Junhao Zhao +2 位作者 Jiahui Liu Peiyuan Ding Jianjian Wang 《Nanotechnology and Precision Engineering》 2025年第3期1-7,共7页
Vibration cutting has emerged as a promising method for creating surface functional microstructures.However,achieving precise tool setting is a time-consuming process that significantly impacts process efficiency.This... Vibration cutting has emerged as a promising method for creating surface functional microstructures.However,achieving precise tool setting is a time-consuming process that significantly impacts process efficiency.This study proposes an intelligent approach for tool setting in vibration cutting using machine vision and hearing,divided into two steps.In the first step,machine vision is employed to achieve rough precision in tool setting within tens of micrometers.Subsequently,in the second step,machine hearing utilizes sound pickup to capture vibration audio signals,enabling fine tool adjustment within 1μm precision.The relationship between the spectral intensity of vibration audio and cutting depth is analyzed to establish criteria for tool–workpiece contact.Finally,the efficacy of this approach is validated on an ultra-precision platform,demonstrating that the automated tool-setting process takes no more than 74 s.The total cost of the vision and hearing sensors is less than$1500. 展开更多
关键词 Vibration cutting Automatic tool setting machine vision machine hearing
在线阅读 下载PDF
Grouped machine learning methods for predicting rock mass parameters in a tunnel boring machine-driven tunnel based on fuzzy C-means clustering
19
作者 Ruirui Wang Yaodong Ni +1 位作者 Lingli Zhang Boyang Gao 《Deep Underground Science and Engineering》 2025年第1期55-71,共17页
To guarantee safe and efficient tunneling of a tunnel boring machine(TBM),rapid and accurate judgment of the rock mass condition is essential.Based on fuzzy C-means clustering,this paper proposes a grouped machine lea... To guarantee safe and efficient tunneling of a tunnel boring machine(TBM),rapid and accurate judgment of the rock mass condition is essential.Based on fuzzy C-means clustering,this paper proposes a grouped machine learning method for predicting rock mass parameters.An elaborate data set on field rock mass is collected,which also matches field TBM tunneling.Meanwhile,target stratum samples are divided into several clusters by fuzzy C-means clustering,and multiple submodels are trained by samples in different clusters with the input of pretreated TBM tunneling data and the output of rock mass parameter data.Each testing sample or newly encountered tunneling condition can be predicted by multiple submodels with the weight of the membership degree of the sample to each cluster.The proposed method has been realized by 100 training samples and verified by 30 testing samples collected from the C1 part of the Pearl Delta water resources allocation project.The average percentage error of uniaxial compressive strength and joint frequency(Jf)of the 30 testing samples predicted by the pure back propagation(BP)neural network is 13.62%and 12.38%,while that predicted by the BP neural network combined with fuzzy C-means is 7.66%and6.40%,respectively.In addition,by combining fuzzy C-means clustering,the prediction accuracies of support vector regression and random forest are also improved to different degrees,which demonstrates that fuzzy C-means clustering is helpful for improving the prediction accuracy of machine learning and thus has good applicability.Accordingly,the proposed method is valuable for predicting rock mass parameters during TBM tunneling. 展开更多
关键词 fuzzy C-means clustering machine learning rock mass parameter tunnel boring machine
原文传递
Development of an emergency department length-of-stay prediction model based on machine learning
20
作者 Weiming Wu Min Li +8 位作者 Huilin Jiang Min Sun Yongcheng Zhu Gongxu Zhu Yanling Li Yunmei Li Junrong Mo Xiaohui Chen Haifeng Mao 《World Journal of Emergency Medicine》 2025年第3期220-224,共5页
BACKGROUND:The problem of prolonged emergency department length of stay(EDLOS) is becoming increasingly crucial.This study aims to develop a machine learning(ML) model to predict EDLOS,with EDLOS as the outcome variab... BACKGROUND:The problem of prolonged emergency department length of stay(EDLOS) is becoming increasingly crucial.This study aims to develop a machine learning(ML) model to predict EDLOS,with EDLOS as the outcome variable and demographic characteristics,triage level,and medical resource utilization as predictive factors.METHODS:A retrospective analysis was performed on the patients who visited the emergency department of the Second Affiliated Hospital of Guangzhou Medical University from March 2019to September 2021,and a total of 321,012 cases were identified.According to the inclusion and exclusion criteria,187,028 cases were finally included in the analysis.ML analysis was performed using R-squared(R^(2)),and the predictive factors and the EDLOS were used as independent variables and dependent variables,respectively,to establish models.The performance evaluation of the ML models was conducted through the utilization of the mean absolute error(MAE),root mean square error(RMSE),and R^(2),enabling an objective comparative analysis.RESULTS:In the comparative analysis of the six ML models,light gradient boosting machine(LightGBM) model demonstrated the lowest MAE(443.519) and RMSE(826.783),and the highest R^(2) value(0.48),indicating better model fit and predictive performance.Among the top 10 predictive factors associated with EDLOS according to the LightGBM model,the emergency waiting time,age,and emergency arrival time had the most significant impact on the EDLOS.CONCLUSION:The LightGBM model suggests that the emergency waiting time,age,and emergency arrival time may be used to predict the EDLOS. 展开更多
关键词 Emergency department machine learning Length of stay Light gradient boosting machine
暂未订购
上一页 1 2 250 下一页 到第
使用帮助 返回顶部