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Research on a Simulation Platform for Typical Internal Corrosion Defects in Natural Gas Pipelines Based on Big Data Analysis
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作者 Changchao Qi Lingdi Fu +2 位作者 Ming Wen Hao Qian Shuai Zhao 《Structural Durability & Health Monitoring》 2025年第4期1073-1087,共15页
The accuracy and reliability of non-destructive testing(NDT)approaches in detecting interior corrosion problems are critical,yet research in this field is limited.This work describes a novel way to monitor the structu... The accuracy and reliability of non-destructive testing(NDT)approaches in detecting interior corrosion problems are critical,yet research in this field is limited.This work describes a novel way to monitor the structural integrity of steel gas pipelines that uses advanced numerical modeling techniques to anticipate fracture development and corrosion effects.The objective is to increase pipeline dependability and safety through more precise,real-time health evaluations.Compared to previous approaches,our solution provides higher accuracy in fault detection and quantification,making it ideal for pipeline integritymonitoring in real-world applications.To solve this issue,statistical analysis was conducted on the size and directional distribution features of about 380,000 sets of internal corrosion faults,as well as simulations of erosion and wear patterns on bent pipes.Using real defectmorphologies,we developed a modeling framework for typical interior corrosion flaws.We evaluated and validated the applicability and effectiveness of in-service inspection processes,as well as conducted on-site comparison tests.The results show that(1)the length and width of corrosion defects follow a log-normal distribution,the clock orientation follows a normal distribution,and the peak depth follows a Freundlich EX function distribution pattern;(2)pipeline corrosion defect data can be classified into three classes using the K-means clustering algorithm,allowing rapid and convenient acquisition of typical size and orientation characteristics of internal corrosion defects;(3)the applicability range and boundary conditions of various NDT techniques were verified,establishing comprehensive selection principles for internal corrosion defect detection technology;(4)on-site inspection results showed a 31%The simulation and validation platform for typical interior corrosion issues greatly enhances the accuracy and reliability of detection data. 展开更多
关键词 Internal corrosion non-destructive testing techniques cluster analysis defect simulation feature analysis typical defects
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Randomized autoregressive dynamic slow feature analysis method for industrial process fault monitoring
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作者 Qingmin Xu Peng Li +3 位作者 Aimin Miao Xun Lang Hancheng Wang Chuangyan Yang 《Chinese Journal of Chemical Engineering》 2025年第7期298-314,共17页
Kernel-based slow feature analysis(SFA)methods have been successfully applied in the industrial process fault detection field.However,kernel-based SFA methods have high computational complexity as dealing with nonline... Kernel-based slow feature analysis(SFA)methods have been successfully applied in the industrial process fault detection field.However,kernel-based SFA methods have high computational complexity as dealing with nonlinearity,leading to delays in detecting time-varying data features.Additionally,the uncertain kernel function and kernel parameters limit the ability of the extracted features to express process characteristics,resulting in poor fault detection performance.To alleviate the above problems,a novel randomized auto-regressive dynamic slow feature analysis(RRDSFA)method is proposed to simultaneously monitor the operating point deviations and process dynamic faults,enabling real-time monitoring of data features in industrial processes.Firstly,the proposed Random Fourier mappingbased method achieves more effective nonlinear transformation,contrasting with the current kernelbased RDSFA algorithm that may lead to significant computational complexity.Secondly,a randomized RDSFA model is developed to extract nonlinear dynamic slow features.Furthermore,a Bayesian inference-based overall fault monitoring model including all RRDSFA sub-models is developed to overcome the randomness of random Fourier mapping.Finally,the superiority and effectiveness of the proposed monitoring method are demonstrated through a numerical case and a simulation of continuous stirred tank reactor. 展开更多
关键词 Slow feature analysis Random Fourier mapping Bayesian Inference Autoregressive dynamic modeling CSTR Fault detection
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Dynamic Process Monitoring Based on Dot Product Feature Analysis for Thermal Power Plants
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作者 Xin Ma Tao Chen Youqing Wang 《IEEE/CAA Journal of Automatica Sinica》 2025年第3期563-574,共12页
Data-driven process monitoring is an effective approach to assure safe operation of modern manufacturing and energy systems,such as thermal power plants being studied in this work.Industrial processes are inherently d... Data-driven process monitoring is an effective approach to assure safe operation of modern manufacturing and energy systems,such as thermal power plants being studied in this work.Industrial processes are inherently dynamic and need to be monitored using dynamic algorithms.Mainstream dynamic algorithms rely on concatenating current measurement with past data.This work proposes a new,alternative dynamic process monitoring algorithm,using dot product feature analysis(DPFA).DPFA computes the dot product of consecutive samples,thus naturally capturing the process dynamics through temporal correlation.At the same time,DPFA's online computational complexity is lower than not just existing dynamic algorithms,but also classical static algorithms(e.g.,principal component analysis and slow feature analysis).The detectability of the new algorithm is analyzed for three types of faults typically seen in process systems:sensor bias,process fault and gain change fault.Through experiments with a numerical example and real data from a thermal power plant,the DPFA algorithm is shown to be superior to the state-of-the-art methods,in terms of better monitoring performance(fault detection rate and false alarm rate)and lower computational complexity. 展开更多
关键词 Computational complexity dot product feature analysis(DPFA) dynamic process multivariate statistics process monitoring
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Correlation analysis between facial feature-based traditional Chinese medicine inspection of spirit classification and Beck Depression Inventory score
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作者 Shan LU Xubo SHANG +2 位作者 Dong YANG Junfeng YAN Xiaoye WANG 《Digital Chinese Medicine》 2025年第2期147-162,共16页
Objective To determine the correlation between traditional Chinese medicine(TCM)inspec-tion of spirit classification and the severity grade of depression based on facial features,offer-ing insights for intelligent int... Objective To determine the correlation between traditional Chinese medicine(TCM)inspec-tion of spirit classification and the severity grade of depression based on facial features,offer-ing insights for intelligent intergrated TCM and western medicine diagnosis of depression.Methods Using the Audio-Visual Emotion Challenge and Workshop(AVEC 2014)public dataset on depression,which conclude 150 interview videos,the samples were classified ac-cording to the TCM inspection of spirit classification:Deshen(得神,presence of spirit),Shaoshen(少神,insufficiency of spirit),and Shenluan(神乱,confusion of spirit).Meanwhile,based on Beck Depression Inventory-II(BDI-II)score for the severity grade of depression,the samples were divided into minimal(0-13,Q1),mild(14-19,Q2),moderate(20-28,Q3),and severe(29-63,Q4).Sixty-eight landmarks were extracted with a ResNet-50 network,and the feature extracion mode was stadardized.Random forest and support vectior machine(SVM)classifiers were used to predict TCM inspection of spirit classification and the severity grade of depression,respectively.A Chi-square test and Apriori association rule mining were then applied to quantify and explore the relationships.Results The analysis revealed a statistically significant and moderately strong association be-tween TCM spirit classification and the severity grade of depression,as confirmed by a Chi-square test(χ^(2)=14.04,P=0.029)with a Cramer’s V effect size of 0.243.Further exploration us-ing association rule mining identified the most compelling rule:“moderate depression(Q3)→Shenluan”.This rule demonstrated a support level of 5%,indicating this specific co-occur-rence was present in 5%of the cohort.Crucially,it achieved a high Confidence of 86%,mean-ing that among patients diagnosed with Q3,86%exhibited the Shenluan pattern according to TCM assessment.The substantial Lift of 2.37 signifies that the observed likelihood of Shenlu-an manifesting in Q3 patients is 2.37 times higher than would be expected by chance if these states were independent-compelling evidence of a highly non-random association.Conse-quently,Shenluan emerges as a distinct and core TCM diagnostic manifestation strongly linked to Q3,forming a clinically significant phenotype within this patient subgroup. 展开更多
关键词 Traditional Chinese medicine inspection of spirit classification Severity grade of depression Facial feature analysis ResNet landmark extraction Association rule mining Clinical intelligent diagnosis
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Corrigendum to“Meta databases of steel frame buildings for surrogate modelling and machine learning-based feature importance analysis”[Journal of Resilient Cities and Structures Volume 3 Issue 1(2024)20-43]
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作者 Delbaz Samadian Jawad Fayaz +2 位作者 Imrose B.Muhit Annalisa Occhipinti Nashwan Dawood 《Resilient Cities and Structures》 2025年第1期124-124,共1页
The authors regret that the original publication of this paper did not include Jawad Fayaz as a co-author.After further discussions and a thorough review of the research contributions,it was agreed that his significan... The authors regret that the original publication of this paper did not include Jawad Fayaz as a co-author.After further discussions and a thorough review of the research contributions,it was agreed that his significant contributions to the foundational aspects of the research warranted recognition,and he has now been added as a co-author. 展开更多
关键词 machine learning meta databases jawad fayaz surrogate modelling feature importance analysis steel frame buildings
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Automatic Satisfaction Analysis in Call Centers Considering Global Features of Emotion and Duration 被引量:1
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作者 Jing Liu Chaomin Wang +7 位作者 Yingnan Zhang Pengyu Cong Liqiang Xu Zhijie Ren Jin Hu Xiang Xie Junlan Feng Jingming Kuang 《Journal of Beijing Institute of Technology》 EI CAS 2018年第1期58-64,共7页
Analysis of customers' satisfaction provides a guarantee to improve the service quality in call centers.In this paper,a novel satisfaction recognition framework is introduced to analyze the customers' satisfaction.I... Analysis of customers' satisfaction provides a guarantee to improve the service quality in call centers.In this paper,a novel satisfaction recognition framework is introduced to analyze the customers' satisfaction.In natural conversations,the interaction between a customer and its agent take place more than once.One of the difficulties insatisfaction analysis at call centers is that not all conversation turns exhibit customer satisfaction or dissatisfaction. To solve this problem,an intelligent system is proposed that utilizes acoustic features to recognize customers' emotion and utilizes the global features of emotion and duration to analyze the satisfaction. Experiments on real-call data show that the proposed system offers a significantly higher accuracy in analyzing the satisfaction than the baseline system. The average F value is improved to 0. 701 from 0. 664. 展开更多
关键词 satisfaction analysis emotion recognition call centers global features of emotion and duration
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Simulation Method and Feature Analysis of Shutdown Pressure Evolution During Multi-Cluster Fracturing Stimulation
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作者 Huaiyin He Longqing Zou +5 位作者 Yanchao Li Yixuan Wang Junxiang Li Huan Wen Bei Chang Lijun Liu 《Energy Engineering》 EI 2024年第1期111-123,共13页
Multistage multi-cluster hydraulic fracturing has enabled the economic exploitation of shale reservoirs,but the interpretation of hydraulic fracture parameters is challenging.The pressure signals after pump shutdown a... Multistage multi-cluster hydraulic fracturing has enabled the economic exploitation of shale reservoirs,but the interpretation of hydraulic fracture parameters is challenging.The pressure signals after pump shutdown are influenced by hydraulic fractures,which can reflect the geometric features of hydraulic fracture.The shutdown pressure can be used to interpret the hydraulic fracture parameters in a real-time and cost-effective manner.In this paper,a mathematical model for shutdown pressure evolution is developed considering the effects of wellbore friction,perforation friction and fluid loss in fractures.An efficient numerical simulation method is established by using the method of characteristics.Based on this method,the impacts of fracture half-length,fracture height,opened cluster and perforation number,and filtration coefficient on the evolution of shutdown pressure are analyzed.The results indicate that a larger fracture half-length may hasten the decay of shutdown pressure,while a larger fracture height can slow down the decay of shutdown pressure.A smaller number of opened clusters and perforations can significantly increase the perforation friction and decrease the overall level of shutdown pressure.A larger filtration coefficient may accelerate the fluid filtration in the fracture and hasten the drop of the shutdown pressure.The simulation method of shutdown pressure,as well as the analysis results,has important implications for the interpretation of hydraulic fracture parameters. 展开更多
关键词 Multistage multi-cluster hydraulic fracturing pump shutdown pressure feature analysis numerical simulation
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Integrating Audio-Visual Features and Text Information for Story Segmentation of News Video 被引量:1
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作者 Liu Hua-yong, Zhou Dong-ru School of Computer,Wuhan University,Wuhan 430072, Hubei, China 《Wuhan University Journal of Natural Sciences》 CAS 2003年第04A期1070-1074,共5页
Video data are composed of multimodal information streams including visual, auditory and textual streams, so an approach of story segmentation for news video using multimodal analysis is described in this paper. The p... Video data are composed of multimodal information streams including visual, auditory and textual streams, so an approach of story segmentation for news video using multimodal analysis is described in this paper. The proposed approach detects the topic-caption frames, and integrates them with silence clips detection results, as well as shot segmentation results to locate the news story boundaries. The integration of audio-visual features and text information overcomes the weakness of the approach using only image analysis techniques. On test data with 135 400 frames, when the boundaries between news stories are detected, the accuracy rate 85.8% and the recall rate 97.5% are obtained. The experimental results show the approach is valid and robust. 展开更多
关键词 news video story segmentation audio-visual features analysis text detection
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Identification of regionalized multiscale microseismic characteristics and rock failure mechanisms under deep mining conditions
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作者 Yihan Zhang Chenliang Hao +3 位作者 Longjun Dong Zhongwei Pei Fangzhen Fan Marc Bascompta 《International Journal of Mining Science and Technology》 2025年第8期1357-1378,共22页
The rock mass failure induced by deep mining exhibits pronounced spatial heterogeneity and diverse mechanisms,with its microseismic responses serving as effective indicators of regional failure evolution and instabili... The rock mass failure induced by deep mining exhibits pronounced spatial heterogeneity and diverse mechanisms,with its microseismic responses serving as effective indicators of regional failure evolution and instability mechanisms.Focusing on the Level VI stope sublayers in the Jinchuan#2 mining area,this study constructs a 24-parameter index system encompassing time-domain features,frequency-domain features,and multifractal characteristics.Through manifold learning,clustering analysis,and hybrid feature selection,15 key indicators were extracted to construct a classification framework for failure responses.Integrated with focal mechanism inversion and numerical simulation,the failure patterns and corresponding instability mechanisms across different structural zones were further identified.The results reveal that multiscale microseismic characteristics exhibit clear regional similarities.Based on the morphological features of radar plots derived from the 15 indicators,acoustic responses were classified into four typical types,each reflecting distinct local failure mechanisms,stress conditions,and plastic zone evolution.Moreover,considering dominant instability factors and rupture modes,four representative rock mass instability models were proposed for typical failure zones within the stope.These findings provide theoretical guidance and methodological support for hazard prediction,structural optimization,and disturbance control in deep metal mining areas. 展开更多
关键词 Microseismic monitoring Rock mass failure mechanism Focal mechanism inversion Multi-scale feature analysis Deep metal mine Numerical simulation
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A novel SMOTE-based ensemble boosting strategy for early diabetes detection
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作者 Bhanu Prakash Lohani Arvind Dagur Dhirendra Kumar Shukla 《Medical Data Mining》 2025年第4期88-95,共8页
Background:Diabetes is one of the fastest rising chronic illness worldwide,and early detection is very crucial for reducing complications.Traditional machine learning models often struggle with imbalanced data and mod... Background:Diabetes is one of the fastest rising chronic illness worldwide,and early detection is very crucial for reducing complications.Traditional machine learning models often struggle with imbalanced data and moderate accuracy.To overcome these limitations,we propose a SMOTE-based ensemble boosting strategy(SMOTEBEnDi)for more accurate diabetes classification.Methods:The framework uses the Pima Indians diabetes dataset(PIDD)consisting of eight clinical features.Preprocessing steps included normalization,feature relevance analysis,and handling of missing values.The class imbalance was corrected using the synthetic minority oversampling technique(SMOTE),and multiple classifiers such as K-nearest neighbor(KNN),decision tree(DT),random forest(RF),and support vector machine(SVM)were ensembled in a boosting architecture.Hyperparameter tuning with k-fold cross validation was applied to ensure robust performance.Results:Experimental analysis showed that the proposed SMOTEBEnDi model achieved 99.5%accuracy,99.39%sensitivity,and 99.59%specificity,outperforming baseline classifiers and demonstrating near-perfect detection.The improvements in performance metrics like area under curve(AUC),precision,and specificity confirm the effectiveness of addressing class imbalance.Conclusion:The study proves that combining SMOTE with ensemble boosting greatly enhances early diabetes detection.This reduces diagnostic errors,supports clinicians in timely intervention,and can serve as a strong base for computer-aided diagnostic tools.Future work should extend this framework for real-time prediction systems,integrate with IoT health devices,and adapt it across diverse clinical datasets to improve generalization and trust in real healthcare settings. 展开更多
关键词 ensemble learning machine learning cross validation feature analysis
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Augmentation of PM_(1.0) measurements based on machine learning model and environmental factors
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作者 Hyemin Hwang Chang Hyeok Kim +3 位作者 Jong-Sung Park Sechan Park Jong Bum Kim Jae Young Lee 《Journal of Environmental Sciences》 2025年第10期91-101,共11页
PM_(1.0),particulate matter with an aerodynamic diameter smaller than 1.0μm,can adversely affect human health.However,fewer stations are capable of measuring PM_(1.0) concentrations than PM2.5 and PM10 concentrations... PM_(1.0),particulate matter with an aerodynamic diameter smaller than 1.0μm,can adversely affect human health.However,fewer stations are capable of measuring PM_(1.0) concentrations than PM2.5 and PM10 concentrations in real time(i.e.,only 9 locations for PM_(1.0) vs.623 locations for PM2.5 or PM10)in South Korea,making it impossible to conduct a nationwide health risk analysis of PM_(1.0).Thus,this study aimed to develop a PM_(1.0) prediction model using a random forest algorithm based on PM_(1.0) data from the nine measurement stations and various environmental input factors.Cross validation,in which the model was trained in eight stations and tested in the remaining station,achieved an average R^(2) of 0.913.The high R^(2) value achieved undermutually exclusive training and test locations in the cross validation can be ascribed to the fact that all the locations had similar relationships between PM_(1.0) and the input factors,which were captured by our model.Moreover,results of feature importance analysis showed that PM2.5 and PM10 concentrations were the two most important input features in predicting PM_(1.0) concentration.Finally,the model was used to estimate the PM_(1.0) concentrations in 623 locations,where input factors such as PM2.5 and PM10 can be obtained.Based on the augmented profile,we identified Seoul and Ansan to be PM_(1.0) concentration hotspots.These regions are large cities or the center of anthropogenic and industrial activities.The proposed model and the augmented PM_(1.0) profiles can be used for large epidemiological studies to understand the health impacts of PM_(1.0). 展开更多
关键词 Particulate matter Random forest Input factor PM_(1.0)prediction model Cross validation Feature importance analysis
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A machine learning framework for accelerating the development of highly efficient methanol synthesis catalysts
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作者 Weixian Li Yi Dong +9 位作者 Mingchu Ran Saisai Lin Peng Liu Hao Song Jundong Yi Chaoyang Zhu Zhifu Qi Chenghang Zheng Xiao Zhang Xiang Gao 《Journal of Energy Chemistry》 2025年第5期372-381,共10页
Converting CO_(2)with green hydrogen to methanol as a carbon-neutral liquid fuel is a promising route for the long-term storage and distribution of intermittent renewable energy.Nevertheless,attaining highly efficient... Converting CO_(2)with green hydrogen to methanol as a carbon-neutral liquid fuel is a promising route for the long-term storage and distribution of intermittent renewable energy.Nevertheless,attaining highly efficient methanol synthesis catalysts from the vast composition space remains a significant challenge.Here we present a machine learning framework for accelerating the development of high space-time yield(STY)methanol synthesis catalysts.A database of methanol synthesis catalysts has been compiled,consisting of catalyst composition,preparation parameters,structural characteristics,reaction conditions and their corresponding catalytic performance.A methodology for constructing catalyst features based on the intrinsic physicochemical properties of the catalyst components has been developed,which significantly reduced the data dimensionality and enhanced the efficiency of machine learning operations.Two high-precision machine learning prediction models for the activities and product selectivity of catalysts were trained and obtained.Using this machine learning framework,an efficient search was achieved within the catalyst composition space,leading to the successful identification of high STY multielement oxide methanol synthesis catalysts.Notably,the CuZnAlTi catalyst achieved high STYs of 0.49 and 0.65 g_(MeOH)/(g_(catalyst)h)for CO_(2)and CO hydrogenation to methanol at 250℃,respectively,and the STY was further increased to 2.63 g_(Me OH)/(g_(catalyst)h)in CO and CO_(2)co-hydrogenation. 展开更多
关键词 Methanol synthesis Machine learning Cu-based catalysts CO/CO_(2)hydrogenation Feature importance analysis
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Machine learning based online fault prognostics for nonstationary industrial process via degradation feature extraction and temporal smoothness analysis 被引量:2
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作者 HU Yun-yun ZHAO Chun-hui KE Zhi-wu 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第12期3838-3855,共18页
Fault degradation prognostic, which estimates the time before a failure occurs and process breakdowns, has been recognized as a key component in maintenance strategies nowadays. Fault degradation processes are, in gen... Fault degradation prognostic, which estimates the time before a failure occurs and process breakdowns, has been recognized as a key component in maintenance strategies nowadays. Fault degradation processes are, in general,slowly varying and can be modeled by autoregressive models. However, industrial processes always show typical nonstationary nature, which may bring two challenges: how to capture fault degradation information and how to model nonstationary processes. To address the critical issues, a novel fault degradation modeling and online fault prognostic strategy is developed in this paper. First, a fault degradation-oriented slow feature analysis(FDSFA) algorithm is proposed to extract fault degradation directions along which candidate fault degradation features are extracted. The trend ability assessment is then applied to select major fault degradation features. Second, a key fault degradation factor(KFDF) is calculated to characterize the fault degradation tendency by combining major fault degradation features and their stability weighting factors. After that, a time-varying regression model with temporal smoothness regularization is established considering nonstationary characteristics. On the basis of updating strategy, an online fault prognostic model is further developed by analyzing and modeling the prediction errors. The performance of the proposed method is illustrated with a real industrial process. 展开更多
关键词 fault prognostic NONSTATIONARY industrial process fault degradation-oriented slow feature analysis(FDSFA) temporal smoothness regularization
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Real-Time Multimodal Biometric Authentication of Human Using Face Feature Analysis 被引量:1
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作者 Rohit Srivastava Ravi Tomar +3 位作者 Ashutosh Sharma Gaurav Dhiman Naveen Chilamkurti Byung-Gyu Kim 《Computers, Materials & Continua》 SCIE EI 2021年第10期1-19,共19页
As multimedia data sharing increases,data security in mobile devices and its mechanism can be seen as critical.Biometrics combines the physiological and behavioral qualities of an individual to validate their characte... As multimedia data sharing increases,data security in mobile devices and its mechanism can be seen as critical.Biometrics combines the physiological and behavioral qualities of an individual to validate their character in real-time.Humans incorporate physiological attributes like a fingerprint,face,iris,palm print,finger knuckle print,Deoxyribonucleic Acid(DNA),and behavioral qualities like walk,voice,mark,or keystroke.The main goal of this paper is to design a robust framework for automatic face recognition.Scale Invariant Feature Transform(SIFT)and Speeded-up Robust Features(SURF)are employed for face recognition.Also,we propose a modified Gabor Wavelet Transform for SIFT/SURF(GWT-SIFT/GWT-SURF)to increase the recognition accuracy of human faces.The proposed scheme is composed of three steps.First,the entropy of the image is removed using Discrete Wavelet Transform(DWT).Second,the computational complexity of the SIFT/SURF is reduced.Third,the accuracy is increased for authentication by the proposed GWT-SIFT/GWT-SURF algorithm.A comparative analysis of the proposed scheme is done on real-time Olivetti Research Laboratory(ORL)and Poznan University of Technology(PUT)databases.When compared to the traditional SIFT/SURF methods,we verify that the GWT-SIFT achieves the better accuracy of 99.32%and the better approach is the GWT-SURF as the run time of the GWT-SURF for 100 images is 3.4 seconds when compared to the GWT-SIFT which has a run time of 4.9 seconds for 100 images. 展开更多
关键词 BIOMETRICS real-time multimodal biometrics real-time face recognition feature analysis
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AUTO-EXTRACTING TECHNIQUE OF DYNAMIC CHAOS FEATURES FOR NONLINEAR TIME SERIES 被引量:6
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作者 CHEN Guo 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第4期524-529,共6页
The main purpose of nonlinear time series analysis is based on the rebuilding theory of phase space, and to study how to transform the response signal to rebuilt phase space in order to extract dynamic feature informa... The main purpose of nonlinear time series analysis is based on the rebuilding theory of phase space, and to study how to transform the response signal to rebuilt phase space in order to extract dynamic feature information, and to provide effective approach for nonlinear signal analysis and fault diagnosis of nonlinear dynamic system. Now, it has already formed an important offset of nonlinear science. But, traditional method cannot extract chaos features automatically, and it needs man's participation in the whole process. A new method is put forward, which can implement auto-extracting of chaos features for nonlinear time series. Firstly, to confirm time delay r by autocorrelation method; Secondly, to compute embedded dimension m and correlation dimension D; Thirdly, to compute the maximum Lyapunov index λmax; Finally, to calculate the chaos degree Dch of Poincare map, and the non-circle degree Dnc and non-order degree Dno of quasi-phase orbit. Chaos features extracting has important meaning to fault diagnosis of nonlinear system based on nonlinear chaos features. Examples show validity of the proposed method. 展开更多
关键词 Nonlinear time series analysis Chaos Feature extracting Fault diagnosis
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Cheminformatics analysis of natural products and indication distribution prediction 被引量:1
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作者 Xin Zhou Yibo Li +2 位作者 Chuanyu Lv Zhenming Liu Liangren Zhang 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2017年第9期635-641,共7页
As a valuable resource for drug discovery, natural products remain largely unexplored. The cheminformatics analysis of natural product databases could help us know better about natural products, providing valuable inf... As a valuable resource for drug discovery, natural products remain largely unexplored. The cheminformatics analysis of natural product databases could help us know better about natural products, providing valuable information in drug design. In this study, we collected an in-home natural product library consisting of more than 220 000 molecules. The results showed that natural products were distributed more diversely than synthetic compounds and approved drugs in chemical space, and natural products still possessed better scaffold diversity. Besides, natural product scaffolds had more potential in some specific indications, such as antiarthritic, antihypertensive, antiallergic and analgesic. However, the utilization rate of natural product scaffolds is relatively low, especially in terms of potential indications. Therefore, we recommend the greater use of natural products while designing lead libraries. 展开更多
关键词 Natural products Feature analysis Indication prediction
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Evaluation of echo features of ultrasonic flaws and its intelligent pattern recognition 被引量:1
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作者 刚铁 吴林 《China Welding》 EI CAS 1997年第1期22-27,共6页
In this paper, three types of weld flaw were taken as target, evaluation and recognition of flaw echo features were studied. On the basis of experimental study and theoretical analysis, 26 features have been extracted... In this paper, three types of weld flaw were taken as target, evaluation and recognition of flaw echo features were studied. On the basis of experimental study and theoretical analysis, 26 features have been extracted from each echo samples. A method which is based on the xtatislical hypothesis testing and used for feature evaluation and optimum subset selection was explored. Thus, the dimensionality reduction of feature space was brought out, and simultaneously the amount of calculation was decreased. An intelligent pattern classifier with B-P type neural network was constructed which was characterized by high speed and accuracy for learning. Using a half of total samples as training set and others as testing set, the learning efficiency and the classification ability of network model were studied. The results of experiment showed that the learning rate of different training samples was about 100%. The results of recognition was satisfactory when the optimum feature subset was taken as the sample's feature vectors. The average recognition rate of three type flaws was about 87.6%, and the best recognition rate amounted to 97%. 展开更多
关键词 ultrasonic detection feature analysis pattern recognition
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Feature Analysis of the Atmospheric Particulate Pollutants (PM_(10) and PM_(2.5)) in Wenzhou City 被引量:1
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作者 Yuequn Song Shufan Ye Qiangqiang Wang 《Meteorological and Environmental Research》 CAS 2013年第4期37-41,共5页
[ Objective] The research aimed to analyze characteristics of the atmospheric particulate pollutants ( PMlo and PM2.s) in Wenzhou City. [Method] We analyzed interannual change rule of the dust haze in Wenzhou during... [ Objective] The research aimed to analyze characteristics of the atmospheric particulate pollutants ( PMlo and PM2.s) in Wenzhou City. [Method] We analyzed interannual change rule of the dust haze in Wenzhou during 1978 -2008. Moreover, we respectively set monitoring points in urban district, industrial park and beauty spot of Wenzhou in summer and winter of 2010. Element, ion and polycyclic aromatic hydrocarbon com- positions and morphology of the particulate matter were analyzed. [ Result] Dust haze in Wenzhou City mainly appeared in winter and spring, which was related to local meteorological condition. In summer and winter, both PMlo and PM2.s concentrations presented the characteristic of industrial park 〉 commercial area 〉 beauty spot. Chain-like particle aggregates and ultrafine particles were main composition of the atmospheric particulate matter in Wenzhou. Contribution rate of the spherical particle amount was smaller than metropolis, which was related to local industry and traffic. Fe element had the most content in particulate matter. Mass concentration was mainly composed of 6 elements, such as Na, Si, S, K, Ca and Fe. Total concentration of the six elements occupied 70% -80% of the 16 elements. SO^- and NH4* in particulate matter were higher. They were mainly from human activity. Main compositions of the polycyclic aromatic hydrocarbon were naphthalene, anthracene, benzo (b) fluoranthene, indeno (1,2, 3-cd) pyrene and benzo (g, h, i) perylene, which was related to abrupt increase of the motor vehicle. [ Condusion] The research provided scientific basis and technology support for controlling atmospheric particulate matter pollution in Wenzhou City by government and related department. 展开更多
关键词 Atmospheric particulate pollutants PM10 PM2.5 Feature analysis China
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Assessment of glaucoma using extreme learning machine and fractal feature analysis
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作者 Subramaniam Kavitha Karuppusamy Duraiswamy Sakthivel Karthikeyan 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2015年第6期1255-1257,共3页
Dear Sir,Iam Dr.Kavitha S,from the Department of Electronics and Communication Engineering,Nandha Engineering College,Erode,Tamil Nadu,India.I write to present the detection of glaucoma using extreme learning machine(... Dear Sir,Iam Dr.Kavitha S,from the Department of Electronics and Communication Engineering,Nandha Engineering College,Erode,Tamil Nadu,India.I write to present the detection of glaucoma using extreme learning machine(ELM)and fractal feature analysis.Glaucoma is the second most frequent cause of permanent blindness in industrial 展开更多
关键词 In Assessment of glaucoma using extreme learning machine and fractal feature analysis ELM FIGURE
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Study on the Features and Risk Assessment of Drought in Guilin
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作者 Xianda Bai 《Meteorological and Environmental Research》 CAS 2013年第2期8-11,共4页
Based on the precipitation data of all counties in Guilin from 1957 to 2010, the analysis has been made on the features of spatial and temporal distribution, the probability of occurrence and the periodic change of dr... Based on the precipitation data of all counties in Guilin from 1957 to 2010, the analysis has been made on the features of spatial and temporal distribution, the probability of occurrence and the periodic change of drought in Guilin. Afterwards, by using the method of disaster risk assessment, the disaster-causing factors, breed disasters environment and fragility of hazard-bearing body of Guilin drought have been analyzed, and the comprehensive evaluation on drought disaster has been made. The results show that above medium drought in Guilin mainly appeared in au- tumn, followed by winter, while Guilin only suffered from slight drought in spring; the principal period of drought occurrence in Guilin was six years, while its secondary period was two years; on the whole, drought risk was high in the southeast and low in the northwest. 展开更多
关键词 Guilin drought Feature analysis Risk assessment China
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