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A New Algorithm of Rain Type Classification for GPM Dual-Frequency Precipitation Radar in Summer Tibetan Plateau
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作者 Yunfei FU Liu YANG +4 位作者 Zhenhao WU Peng ZHANG Songyan GU Lin CHEN Sun NAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第11期2093-2111,共19页
In this study, a new rain type classification algorithm for the Dual-Frequency Precipitation Radar(DPR) suitable over the Tibetan Plateau(TP) was proposed by analyzing Global Precipitation Measurement(GPM) DPR Level-2... In this study, a new rain type classification algorithm for the Dual-Frequency Precipitation Radar(DPR) suitable over the Tibetan Plateau(TP) was proposed by analyzing Global Precipitation Measurement(GPM) DPR Level-2 data in summer from 2014 to 2020. It was found that the DPR rain type classification algorithm(simply called DPR algorithm) has mis-identification problems in two aspects in summer TP. In the new algorithm of rain type classification in summer TP,four rain types are classified by using new thresholds, such as the maximum reflectivity factor, the difference between the maximum reflectivity factor and the background maximum reflectivity factor, and the echo top height. In the threshold of the maximum reflectivity factors, 30 d BZ and 18 d BZ are both thresholds to separate strong convective precipitation, weak convective precipitation and weak precipitation. The results illustrate obvious differences of radar reflectivity factor and vertical velocity among the three rain types in summer TP, such as the reflectivity factor of most strong convective precipitation distributes from 15 d BZ to near 35 d BZ from 4 km to 13 km, and increases almost linearly with the decrease in height. For most weak convective precipitation, the reflectivity factor distributes from 15 d BZ to 28 d BZ with the height from 4 km to 9 km. For weak precipitation, the reflectivity factor mainly distributes in range of 15–25 d BZ with height within 4–10 km. It is also shows that weak precipitation is the dominant rain type in summer TP, accounting for 40%–80%,followed by weak convective precipitation(25%–40%), and strong convective precipitation has the least proportion(less than 30%). 展开更多
关键词 satellite precipitation radar rain type classification method Tibetan Plateau strong convective precipitation
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Data-driven casting defect prediction model for sand casting based on random forest classification algorithm
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作者 Bang Guan Dong-hong Wang +3 位作者 Da Shu Shou-qin Zhu Xiao-yuan Ji Bao-de Sun 《China Foundry》 SCIE EI CAS CSCD 2024年第2期137-146,共10页
The complex sand-casting process combined with the interactions between process parameters makes it difficult to control the casting quality,resulting in a high scrap rate.A strategy based on a data-driven model was p... The complex sand-casting process combined with the interactions between process parameters makes it difficult to control the casting quality,resulting in a high scrap rate.A strategy based on a data-driven model was proposed to reduce casting defects and improve production efficiency,which includes the random forest(RF)classification model,the feature importance analysis,and the process parameters optimization with Monte Carlo simulation.The collected data includes four types of defects and corresponding process parameters were used to construct the RF model.Classification results show a recall rate above 90% for all categories.The Gini Index was used to assess the importance of the process parameters in the formation of various defects in the RF model.Finally,the classification model was applied to different production conditions for quality prediction.In the case of process parameters optimization for gas porosity defects,this model serves as an experimental process in the Monte Carlo method to estimate a better temperature distribution.The prediction model,when applied to the factory,greatly improved the efficiency of defect detection.Results show that the scrap rate decreased from 10.16% to 6.68%. 展开更多
关键词 sand casting process data-driven method classification model quality prediction feature importance
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Classification and rating of disintegrated dolomite strata for slope stability analysis
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作者 Wenlian Liu Xinyue Gong +3 位作者 Jiaxing Dong Hanhua Xu Peixuan Dai Shengwei Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2552-2562,共11页
Although disintegrated dolomite,widely distributed across the globe,has conventionally been a focus of research in underground engineering,the issue of slope stability issues in disintegrated dolomite strata is gainin... Although disintegrated dolomite,widely distributed across the globe,has conventionally been a focus of research in underground engineering,the issue of slope stability issues in disintegrated dolomite strata is gaining increasing prominence.This is primarily due to their unique properties,including low strength and loose structure.Current methods for evaluating slope stability,such as basic quality(BQ)and slope stability probability classification(SSPC),do not adequately account for the poor integrity and structural fragmentation characteristic of disintegrated dolomite.To address this challenge,an analysis of the applicability of the limit equilibrium method(LEM),BQ,and SSPC methods was conducted on eight disintegrated dolomite slopes located in Baoshan,Southwest China.However,conflicting results were obtained.Therefore,this paper introduces a novel method,SMRDDS,to provide rapid and accurate assessment of disintegrated dolomite slope stability.This method incorporates parameters such as disintegrated grade,joint state,groundwater conditions,and excavation methods.The findings reveal that six slopes exhibit stability,while two are considered partially unstable.Notably,the proposed method demonstrates a closer match with the actual conditions and is more time-efficient compared with the BQ and SSPC methods.However,due to the limited research on disintegrated dolomite slopes,the results of the SMRDDS method tend to be conservative as a safety precaution.In conclusion,the SMRDDS method can quickly evaluate the current situation of disintegrated dolomite slopes in the field.This contributes significantly to disaster risk reduction for disintegrated dolomite slopes. 展开更多
关键词 Disintegrated dolomite slope Basic quality(BQ) Slope stability probability classification (SSPC) Rock mass quality classification Limit equilibrium method(LEM)
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Coal-rock gas:Concept,connotation and classification criteria
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作者 LI Guoxin ZHANG Shuichang +11 位作者 HE Haiqing HE Xinxing ZHAO Zhe NIU Xiaobing XIONG Xianyue ZHAO Qun GUO Xujie HOU Yuting ZHANG Lei LIANG Kun DUAN Xiaowen ZHAO Zhenyu 《Petroleum Exploration and Development》 SCIE 2024年第4期897-911,共15页
In recent years,great breakthroughs have been made in the exploration and development of natural gas in deep coal-rock reservoirs in Junggar,Ordos and other basins in China.In view of the inconsistency between the ind... In recent years,great breakthroughs have been made in the exploration and development of natural gas in deep coal-rock reservoirs in Junggar,Ordos and other basins in China.In view of the inconsistency between the industrial and academic circles on this new type of unconventional natural gas,this paper defines the concept of"coal-rock gas"on the basis of previous studies,and systematically analyzes its characteristics of occurrence state,transport and storage form,differential accumulation,and development law.Coal-rock gas,geologically unlike coalbed methane in the traditional sense,occurs in both free and adsorbed states,with free state in abundance.It is generated and stored in the same set of rocks through short distance migration,occasionally with the accumulation from other sources.Moreover,coal rock develops cleat fractures,and the free gas accumulates differentially.The coal-rock gas reservoirs deeper than 2000 m are high in pressure,temperature,gas content,gas saturation,and free-gas content.In terms of development,similar to shale gas and tight gas,coal-rock gas can be exploited by natural formation energy after the reservoirs connectivity is improved artificially,that is,the adsorbed gas is desorbed due to pressure drop after the high-potential free gas is recovered,so that the free gas and adsorbed gas are produced in succession for a long term without water drainage for pressure drop.According to buried depth,coal rank,pressure coefficient,reserves scale,reserves abundance and gas well production,the classification criteria and reserves/resources estimation method of coal-rock gas are presented.It is preliminarily estimated that the coal-rock gas in place deeper than 2000 m in China exceeds 30×10^(12)m^(3),indicating an important strategic resource for the country.The Ordos,Sichuan,Junggar and Bohai Bay basins are favorable areas for large-scale enrichment of coal-rock gas.The paper summarizes the technical and management challenges and points out the research directions,laying a foundation for the management,exploration,and development of coal-rock gas in China. 展开更多
关键词 coal-rock gas coalbed methane adsorbed gas free gas classification criteria reserves estimation method
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Classification and reconstructive algorithm for nasal alar defect in Asians
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作者 Renpeng Zhou Dongze Lyu +1 位作者 Chen Wang Danru Wang 《Chinese Journal of Plastic and Reconstructive Surgery》 2024年第1期22-27,共6页
Background:The nasal alar defect in Asians remains a challenging issue,as do clear classification and algorithm guidance,despite numerous previously described surgical techniques.The aim of this study is to propose a ... Background:The nasal alar defect in Asians remains a challenging issue,as do clear classification and algorithm guidance,despite numerous previously described surgical techniques.The aim of this study is to propose a surgical algorithm that addresses the appropriate surgical procedures for different types of nasal alar defects in Asian patients.Methods:A retrospective case note review was conducted on 32 patients with nasal alar defect who underwent reconstruction between 2008 and 2022.Based on careful analysis and our clinical experience,we proposed a classification system for nasal alar defects and presented a reconstructive algorithm.Patient data,including age,sex,diagnosis,surgical options,and complications,were assessed.The extent of surgical scar formation was evaluated using standard photography based on a 4-grade scar scale.Results:Among the 32 patients,there were 20 males and 12 females with nasal alar defects.The predominant cause of trauma in China was industrial factors.The majority of alar defects were classified as type Ⅰ C(n=8,25%),comprising 18 cases(56.2%);there were 5 cases(15.6%)of type Ⅱ defect,7(21.9%)of type Ⅲ defect,and 2(6.3%)of type Ⅳ defect.The most common surgical option was auricular composite graft(n=8,25%),followed by bilobed flap(n=6,18.8%),free auricular composite flap(n=4,12.5%),and primary closure(n=3,9.4%).Satisfactory improvements were observed postoperatively.Conclusion:Factors contributing to classifications were analyzed and defined,providing a framework for the proposed classification system.The reconstructive algorithm offers surgeons appropriate procedures for treating nasal alar defect in Asians. 展开更多
关键词 Nasal alar DEFECT classification ALGORITHM Surgical methods
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Improvement of X-Band Polarization Radar Melting Layer Recognition by the Bayesian Method and ITS Impact on Hydrometeor Classification 被引量:4
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作者 Jianli MA Zhiqun HU +1 位作者 Meilin YANG Siteng LI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2020年第1期105-116,共12页
Using melting layer(ML)and non-melting layer(NML)data observed with the X-band dual linear polarization Doppler weather radar(X-POL)in Shunyi,Beijing,the reflectivity(ZH),differential reflectivity(ZDR),and correlation... Using melting layer(ML)and non-melting layer(NML)data observed with the X-band dual linear polarization Doppler weather radar(X-POL)in Shunyi,Beijing,the reflectivity(ZH),differential reflectivity(ZDR),and correlation coefficient(CC)in the ML and NML are obtained in several stable precipitation processes.The prior probability density distributions(PDDs)of the ZH,ZDR and CC are calculated first,and then the probabilities of ZH,ZDR and CC at each radar gate are determined(PBB in the ML and PNB in the NML)by the Bayesian method.When PBB>PNB the gate belongs to the ML,and when PBB<PNB the gate belongs to the NML.The ML identification results with the Bayesian method are contrasUsing melting layer(ML)and non-melting layer(NML)data observed with the X-band dual linear polarization Doppler weather radar(X-POL)in Shunyi,Beijing,the reflectivity(ZH),differential reflectivity(ZDR),and correlation coefficient(CC)in the ML and NML are obtained in several stable precipitation processes.The prior probability density distributions(PDDs)of the ZH,ZDR and CC are calculated first,and then the probabilities of ZH,ZDR and CC at each radar gate are determined(PBB in the ML and PNB in the NML)by the Bayesian method.When PBB>PNB the gate belongs to the ML,and when PBB<PNB the gate belongs to the NML.The ML identification results with the Bayesian method are contrasted under the conditions of the independent PDDs and joint PDDs of the ZH,ZDR and CC.The results suggest that MLs can be identified effectively,although there are slight differences between the two methods.Because the values of the polarization parameters are similar in light rain and dry snow,it is difficult for the polarization radar to distinguish them.After using the Bayesian method to identify the ML,light rain and dry snow can be effectively separated with the X-POL observed data.ted under the conditions of the independent PDDs and joint PDDs of the ZH,ZDR and CC.The results suggest that MLs can be identified effectively,although there are slight differences between the two methods.Because the values of the polarization parameters are similar in light rain and dry snow,it is difficult for the polarization radar to distinguish them.After using the Bayesian method to identify the ML,light rain and dry snow can be effectively separated with the X-POL observed data. 展开更多
关键词 X-band polarimetric radar Bayesian method melting layer identification hydrometeor classification
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Three-dimensional Extension of the Unit-Feature Spatial Classification Method for Cloud Type 被引量:1
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作者 张成伟 郁凡 +1 位作者 王晨曦 杨建宇 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2011年第3期601-611,共11页
We describe how the Unit-Feature Spatial Classification Method(UFSCM) can be used operationally to classify cloud types in satellite imagery efficiently and conveniently.By using a combination of Interactive Data Lang... We describe how the Unit-Feature Spatial Classification Method(UFSCM) can be used operationally to classify cloud types in satellite imagery efficiently and conveniently.By using a combination of Interactive Data Language(IDL) and Visual C++(VC) code in combination to extend the technique in three dimensions(3-D),this paper provides an efficient method to implement interactive computer visualization of the 3-D discrimination matrix modification,so as to deal with the bi-spectral limitations of traditional two dimensional(2-D) UFSCM.The case study of cloud-type classification based on FY-2C satellite data (0600 UTC 18 and 0000 UTC 10 September 2007) is conducted by comparison with ground station data, and indicates that 3-D UFSCM makes more use of the pattern recognition information in multi-spectral imagery,resulting in more reasonable results and an improvement over the 2-D method. 展开更多
关键词 cloud-type classification unit-feature spatial classification method three dimensions
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An overview of thermoelectric films:Fabrication techniques,classification,and regulation methods 被引量:1
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作者 Jing-jing Feng Wei Zhu Yuan Deng 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第4期12-26,共15页
Thermoelectric materials have aroused widespread concern due to their unique ability to directly convert heat to electricity without any moving parts or noxious emissions.Taking advantages of two-dimensional structure... Thermoelectric materials have aroused widespread concern due to their unique ability to directly convert heat to electricity without any moving parts or noxious emissions.Taking advantages of two-dimensional structures of thermoelectric films,the potential applications of thermoelectric materials are diversified,particularly in microdevices.Well-controlled nanostructures in thermoelectric films are effective to optimize the electrical and thermal transport,which can significantly improve the performance of thermoelectric materials.In this paper,various physical and chemical approaches to fabricate thermoelectric films,including inorganic,organic,and inorganic–organic composites,are summarized,where more attentions are paid on the inorganic thermoelectric films for their excellent thermoelectric responses.Additionally,strategies for enhancing the performance of thermoelectric films are also discussed. 展开更多
关键词 thermoelectric films fabrication techniques classification regulation methods
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Research Dynamics of the Classification Methods of Remote Sensing Images 被引量:1
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作者 Yan ZHANG Baoguo WU Dong WANG 《Asian Agricultural Research》 2013年第3期118-122,共5页
As the key technology of extracting remote sensing information,the classification of remote sensing images has always been the research focus in the field of remote sensing. The paper introduces the classification pro... As the key technology of extracting remote sensing information,the classification of remote sensing images has always been the research focus in the field of remote sensing. The paper introduces the classification process and system of remote sensing images. According to the recent research status of domestic and international remote sensing classification methods,the new study dynamics of remote sensing classification,such as artificial neural networks,support vector machine,active learning and ensemble multi-classifiers,were introduced,providing references for the automatic and intelligent development of remote sensing images classification. 展开更多
关键词 REMOTE SENSING IMAGES classification methods CLASS
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An integrated classification method for thematic mapper imagery of plain and highland terrains 被引量:1
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作者 Shan-long LU Xiao-hua SHEN +6 位作者 Le-jun ZOU Chang-jiang LI Yan-jun MAO Gui-fang ZHANG Wen-yuan WU Ying LIU Zhong ZHANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第6期858-866,共9页
The classification of thematic mapper imagery in areas with strong topographic variations has proven problematic in the past using a single classifier, due to the changing sun illumination geometry. This often results... The classification of thematic mapper imagery in areas with strong topographic variations has proven problematic in the past using a single classifier, due to the changing sun illumination geometry. This often results in the phenomena of identical object with dissimilar spectrum and different objects with similar spectrum. In this paper, an integrated classification method that combines a decision tree with slope data, tasseled cap transformation indices and maximum likelihood classifier is introduced, to find an optimal classification method for thematic mapper imagery of plain and highland terrains. A Landsat 7 ETM+ image acquired over Hangzhou Bay, in eastern China was used to test the method. The results indicate that the performance of the inte- grated classifier is acceptably good in comparison with that of the existing most widely used maximum likelihood classifier. The integrated classifier depends on hypsography (variation in topography) and the characteristics of ground truth objects (plant and soil). It can greatly reduce the influence of the homogeneous spectrum caused by topographic variation. This integrated classifier might potentially be one of the most accurate classifiers and valuable tool for land cover and land use mapping of plain and highland terrains. 展开更多
关键词 Image classification Land cover and land use Thematic mapper imagery Plain and highland terrains Integratedclassification method
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Classification of Preparation Methods and Wearability of Smart Textiles 被引量:1
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作者 FANG Jialu DU Jianxia 《Journal of Donghua University(English Edition)》 CAS 2022年第4期379-391,共13页
In recent years,smart textiles have attracted the attention of scholars from all walks of life,but there is an imbalance between functionality and usability,which affects their marketization process.Firstly,five repre... In recent years,smart textiles have attracted the attention of scholars from all walks of life,but there is an imbalance between functionality and usability,which affects their marketization process.Firstly,five representative smart textiles are introduced and their respective wearability is described around preparation methods.Secondly,it is concluded that the preparation methods of smart textiles can be divided into two categories:fiber methods and finishing methods.The fiber methods refer to making smart fibers into smart textiles.Textiles made by fiber methods are breathable and feel good in the hand,but the mechanical properties are influenced by the production equipment,and the process cost is high.The finishing methods refer to the functional finishing of ordinary textiles.Although the finishing method is simple and convenient,it may reduce the comfort of the textile.Finally,applications and new research in various fields of smart textiles are presented with promising prospects.It is anticipated that this review will serve as a theoretical basis for future research and development of smart textiles.Researchers are expected to create new technologies to overcome the tension between functionality and usability,as well as to increase user comfort and convenience. 展开更多
关键词 smart textiles classification of preparation method WEARABILITY FUNCTIONALITY fabric comfort
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A NEW METHOD FOR CLASSIFICATION OF ROCK DRILLABILITY
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作者 Lu, Fan Central-South University of Technology, Changsha 410083, China 《中国有色金属学会会刊:英文版》 CSCD 1993年第3期76-80,共5页
A New method of rock drillability classification for impregnated diamond drilling is recommended. The essence of the method is comparing the area of the slots cut respectively on a standard synthetic rock sample and t... A New method of rock drillability classification for impregnated diamond drilling is recommended. The essence of the method is comparing the area of the slots cut respectively on a standard synthetic rock sample and the rock sample being classified by one diamond saw to determine the rock drillability in diamond core drilling. This method has the advantages of good in simulation and stable in comparison standard. 展开更多
关键词 ROCK DRILLABILITY classification DIAMOND core DRILLING cutting-comparison method
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On Eigen-Matrix Translation Method for Classification of Biological Data
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作者 JIANG Hao QIU Yushan +1 位作者 CHENG Xiaoqing CHING Waiki 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第5期1212-1230,共19页
Driven by the challenge of integrating large amount of experimental data, classification technique emerges as one of the major and popular tools in computational biology and bioinformatics research. Machine learning m... Driven by the challenge of integrating large amount of experimental data, classification technique emerges as one of the major and popular tools in computational biology and bioinformatics research. Machine learning methods, especially kernel methods with Support Vector Machines (SVMs) are very popular and effective tools. In the perspective of kernel matrix, a technique namely Eigen- matrix translation has been introduced for protein data classification. The Eigen-matrix translation strategy has a lot of nice properties which deserve more exploration. This paper investigates the major role of Eigen-matrix translation in classification. The authors propose that its importance lies in the dimension reduction of predictor attributes within the data set. This is very important when the dimension of features is huge. The authors show by numerical experiments on real biological data sets that the proposed framework is crucial and effective in improving classification accuracy. This can therefore serve as a novel perspective for future research in dimension reduction problems. 展开更多
关键词 classification dimension reduction eigen-matrix translation glycan data kernel method(KM) support vector machine (SVM)
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A classification method of building structures based on multi-feature fusion of UAV remote sensing images
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作者 Haoguo Du Yanbo Cao +6 位作者 Fanghao Zhang Jiangli Lv Shurong Deng Yongkun Lu Shifang He Yuanshuo Zhang Qinkun Yu 《Earthquake Research Advances》 CSCD 2021年第4期38-47,共10页
In order to improve the accuracy of building structure identification using remote sensing images,a building structure classification method based on multi-feature fusion of UAV remote sensing image is proposed in thi... In order to improve the accuracy of building structure identification using remote sensing images,a building structure classification method based on multi-feature fusion of UAV remote sensing image is proposed in this paper.Three identification approaches of remote sensing images are integrated in this method:object-oriented,texture feature,and digital elevation based on DSM and DEM.So RGB threshold classification method is used to classify the identification results.The accuracy of building structure classification based on each feature and the multi-feature fusion are compared and analyzed.The results show that the building structure classification method is feasible and can accurately identify the structures in large-area remote sensing images. 展开更多
关键词 Remote sensing image Building structure classification Multi-feature fusion Object-oriented classification method Texture feature classification method DSM and DEM elevation classification method RGB threshold classification method
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Using Hybrid and Diversity-Based Adaptive Ensemble Method for Binary Classification
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作者 Xing Fan Chung-Horng Lung Samuel A. Ajila 《International Journal of Intelligence Science》 2018年第3期43-74,共32页
This paper proposes an adaptive and diverse hybrid-based ensemble method to improve the performance of binary classification. The proposed method is a non-linear combination of base models and the application of adapt... This paper proposes an adaptive and diverse hybrid-based ensemble method to improve the performance of binary classification. The proposed method is a non-linear combination of base models and the application of adaptive selection of the most suitable model for each data instance. Ensemble method, an important machine learning technique uses multiple single models to construct a hybrid model. A hybrid model generally performs better compared to a single individual model. In a given dataset the application of diverse single models trained with different machine learning algorithms will have different capabilities in recognizing patterns in the given training sample. The proposed approach has been validated on Repeat Buyers Prediction dataset and Census Income Prediction dataset. The experiment results indicate up to 18.5% improvement on F1 score for the Repeat Buyers dataset compared to the best individual model. This improvement also indicates that the proposed ensemble method has an exceptional ability of dealing with imbalanced datasets. In addition, the proposed method outperforms two other commonly used ensemble methods (Averaging and Stacking) in terms of improved F1 score. Finally, our results produced a slightly higher AUC score of 0.718 compared to the previous result of AUC score of 0.712 in the Repeat Buyers competition. This roughly 1% increase AUC score in performance is significant considering a very big dataset such as Repeat Buyers. 展开更多
关键词 Bigdata ANALYTICS MACHINE Learning ADAPTIVE ENSEMBLE methods BINARY classification
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Man-Computer Interactive Method on Cloud Classification Based on Bispectral Satellite Imagery
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《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1997年第3期102-111,共10页
Man-ComputerInteractiveMethodonCloudClasificationBasedonBispectralSateliteImageryYuFan(郁凡),LiuChangsheng(刘长盛... Man-ComputerInteractiveMethodonCloudClasificationBasedonBispectralSateliteImageryYuFan(郁凡),LiuChangsheng(刘长盛)DepartmentofAtmo... 展开更多
关键词 Man-Computer Interactive method on Cloud classification Based on Bispectral Satellite IMAGERY 刘长
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Comparative Study of the Geomagnetic Activity Effect on foF2 Variation as Defined by the Two Classification Methods at Dakar Station over Solar Cycle Phases
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作者 Sibri Alphonse Sandwidi Doua Allain Gnabahou Frédéric Ouattara 《International Journal of Geosciences》 2020年第8期501-517,共17页
This paper aims to establish a comparison between both geomagnetic activity classification methods on foF2 diurnal variation over solar cycle phases. It concerns first a comparison of geomagnetic activity occurrences ... This paper aims to establish a comparison between both geomagnetic activity classification methods on foF2 diurnal variation over solar cycle phases. It concerns first a comparison of geomagnetic activity occurrences according to both classification methods;and second the geomagnetic effect on foF2 diurnal variation profiles as defined for the equatorial latitudes. The occurrences of the different disturbed geomagnetic activities (recurrent activity (RA), shock activity (SA) and fluctuant activity (FA)) according to both classifications (ancient classification (AC) and new classification (NC)) have been studied at Dakar ionosonde station (Lat: 14.8°N;Long: 342.6°E). Regarding both classifications, the RA occurs more during the decreasing phase. And it’s observed that the RA occurs the most during the increasing phase for the AC and during the minimum phase for the NC. The maximum gap of occurrence (<img src="Edit_e4627ea9-9a9a-4473-9017-202d04a16377.bmp" alt="" /><span><span style="font-family:Verdana;">) between both classifications is <span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&#45</span></span></span><span style="font-family:;" "=""><span style="font-family:Verdana;">11.1%</span><span style="font-family:Verdana;"> (for the negative value which is observed during the increasing phase) and </span><span style="font-family:Verdana;">+16.74%</span><span style="font-family:Verdana;"> (for the positive one which is observed during the decreasing phase). The occurrence of the SA in relation with both classifications is the lowest during the minimum phase and the maximum occurrence is observed during the maximum and decreasing phases, for the AC, with a value close to </span><span style="font-family:Verdana;">37%</span><span style="font-family:Verdana;"> and for the NC at the maximum phase with a percentage of </span><span style="font-family:Verdana;">54.47%</span><span><span style="font-family:Verdana;">. The maximum gap of occurrence (</span><img src="Edit_20fa141b-ecee-4e06-8024-144ba0969395.bmp" alt="" /></span></span><span style="font-family:Verdana;">) between both classifications is <span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&#45</span></span></span><span style="font-family:;" "=""><span style="font-family:Verdana;">17.85%</span><span style="font-family:Verdana;"> (for the negative value which is observed at maximum phase) and </span><span style="font-family:Verdana;">+13.53%</span><span style="font-family:Verdana;"> (for the positive one which is observed during the decreasing phase). For both classifications, the FA occurs the least during the minimum phase and the most during the maximum phase for the AC and at maximum and decreasing phases with percentage values of occurrence of roughly </span><span style="font-family:Verdana;">37%</span><span><span style="font-family:Verdana;"> for the NC. The maximum gap of occurrence (</span><img src="Edit_eecb8939-783e-4d43-b92c-80c528c1890b.bmp" alt="" /><span style="font-family:Verdana;"></span></span></span><span style="font-family:Verdana;">) between both classifications is <span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&#45</span></span>10% (for the negative value which is observed during the decreasing phase) and </span><span style="font-family:;" "=""><span style="font-family:Verdana;">+20.11%</span><span style="font-family:Verdana;"> (for the positive one which is observed during the maximum phase). foF2 diurnal profiles throughout solar cycle phases concerning the AC and the NC have been compared. The FA diurnal profiles don’t present a difference. The RA and the SA present a difference during minimum and increasing phases and the least at maximum and decreasing phases.</span></span></span> 展开更多
关键词 Geomagnetic Activity classification method Solar Cycle Phases foF2 Diurnal Profile
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Symmetry Classification of Partial Differential Equations Based on Wu's Method
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作者 TIAN Yi WAN Jianxiong 《Journal of Donghua University(English Edition)》 CAS 2021年第2期187-192,共6页
Lie algorithm combined with differential form Wu's method is used to complete the symmetry classification of partial differential equations(PDEs)containing arbitrary parameter.This process can be reduced to solve ... Lie algorithm combined with differential form Wu's method is used to complete the symmetry classification of partial differential equations(PDEs)containing arbitrary parameter.This process can be reduced to solve a large system of determining equations,which seems rather difficult to solve,then the differential form Wu's method is used to decompose the determining equations into a series of equations,which are easy to solve.To illustrate the usefulness of this method,we apply it to some test problems,and the results show the performance of the present work. 展开更多
关键词 Lie algorithm differential form Wu's method determining equation symmetry classification partial differential equation(PDE)
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Classification of regional agricultural structure:method and its application to China
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作者 Mou Ziping Lei Hongmei +1 位作者 Chen Guangping Li Xin 《Ecological Economy》 2008年第4期410-417,共8页
Regional agriculture is the basis of regional sustainable development, so sustainable regional agricultural development is essential to the sustainable development of the whole society and becomes the focus of global ... Regional agriculture is the basis of regional sustainable development, so sustainable regional agricultural development is essential to the sustainable development of the whole society and becomes the focus of global research. The classification of regional agricultural structure is the basic work of regional agriculture study. This paper constructs index system (27 indices) of regional agricultural structure types with the three big indices: natural resources, developmental level of the agro-economy, and agro-ecological conditions. This paper also endows weight to every sub-classification index by means of AHP and obtains the comprehensive evaluation value of the three types of indices with arithmetic average weight approach. The regional agricultural structure can be classified into eight types in accordance with this evaluation results. The empirical study of China shows that the 31 provinces (municipalities and autonomous regions) are of different agriculture structural types. Finally, countermeasures of sustainsable agricultural development are put forward for the different agriculture structure features. 展开更多
关键词 AGRO-ECOLOGY China classification method Regional agriculture Structural type
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Method for the classification of tea diseases via weighted sampling and hierarchical classification learning
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作者 Rujia Li Weibo Qin +5 位作者 Yiting He Yadong Li Rongbiao Ji Yehui Wu Jiaojiao Chen Jianping Yang 《International Journal of Agricultural and Biological Engineering》 SCIE 2024年第3期211-221,共11页
This study proposed a weighted sampling hierarchical classification learning method based on an efficient backbone network model to address the problems of high costs,low accuracy,and time-consuming traditional tea di... This study proposed a weighted sampling hierarchical classification learning method based on an efficient backbone network model to address the problems of high costs,low accuracy,and time-consuming traditional tea disease recognition methods.This method enhances the feature extraction ability by conducting hierarchical classification learning based on the EfficientNet model,effectively alleviating the impact of high similarity between tea diseases on the model’s classification performance.To better solve the problem of few and unevenly distributed tea disease samples,this study introduced a weighted sampling scheme to optimize data processing,which not only alleviates the overfitting effect caused by too few sample data but also balances the probability of extracting imbalanced classification data.The experimental results show that the proposed method was significant in identifying both healthy tea leaves and four common leaf diseases of tea(tea algal spot disease,tea white spot disease,tea anthracnose disease,and tea leaf blight disease).After applying the“weighted sampling hierarchical classification learning method”to train 7 different efficient backbone networks,most of their accuracies have improved.The EfficientNet-B1 model proposed in this study achieved an accuracy rate of 99.21%after adopting this learning method,which is higher than EfficientNet-b2(98.82%)and MobileNet-V3(98.43%).In addition,to better apply the results of identifying tea diseases,this study developed a mini-program that operates on WeChat.Users can quickly obtain accurate identification results and corresponding disease descriptions and prevention methods through simple operations.This intelligent tool for identifying tea diseases can serve as an auxiliary tool for farmers,consumers,and related scientific researchers and has certain practical value. 展开更多
关键词 tea diseases hierarchical classification learning weighted sampling classification method EfficientNet miniprogram
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