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Principal component and cluster analysis of coffee production environmentsin the Gedeo Zone of southern Ethiopia 认领 引用
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作者 Tedla Getahun Girma Mamo +2 位作者 Daniel Markos Getahun Haile Gebremedhin Tesfaye 《Beverage Plant Research》 CAS 2025年第1期126-137,共12页
Despite the importance of coffee,there is a lack of comprehensive analysis to understand the key factors influencing coffee production across the Gedeo Zone of southern Ethiopia.We used principal component and cluster... Despite the importance of coffee,there is a lack of comprehensive analysis to understand the key factors influencing coffee production across the Gedeo Zone of southern Ethiopia.We used principal component and cluster analysis approaches to minimize the dimensionality of the data gathered from the study area's topography,climate,soil analysis,farmers'interviews,and geographic information systems.Data from coffee farm records spanning ten years(2013-2022)were collected from 18 rural kebeles in the area.The first 12 principal components explained 95.4%of the total variation.The cation exchange capacity of soils contributed 22.5%of the variation in the first principal component,while evapotranspiration and shade trees explained 16.1%and 11.9%,respectively of variability in coffee productivity.Total nitrogen,altitude,and ash explained 10.5%,8.1%,and 5.8%of variability whereas organic carbon,iron,soil water conservation,Normalized Difference Vegetation Index,variety,and clay explained 5.0%,4.0%,3.3%,3.2%,2.9%,and 2.1%,respectively.The 18 kebeles were reduced to five clusters(Tumata chiracha,Hama,Dumerso,Konga,and Wotiko),which differed for all characteristics(p<0.001),and Konga and Wotiko clusters concentrated 39.0%(2.184)of the information with higher productivity of coffee.Similarly,the 58 variables were reduced to cation exchange capacity,clay content of soils,total nitrogen,evapotranspiration,shade trees,altitude,ash,organic carbon,iron,soil water conservation,NDVI,and variety,which were considered the most representative traits explaining the variability of the data set.Thus,farmers,agricultural planners,and policymakers shall embark on a different set of planning schemes,varietal choices,and management practices that maximize the quality and yield of coffee for each cluster. 展开更多
关键词 geographic information systemsdata Southern Ethiopia cluster analysis cluster analysis approaches understand key factors influencing Gedeo Zone principal component principal component analysis
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Distribution of Traditional Chinese Medicine Syndromes and Syndrome Elements of Chronic Heart Failure Based on Network Analysis and Hierarchical Cluster Analysis 认领 引用
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作者 ZHOU Yi HUANG Pinxian +1 位作者 LI Xiaoqian HE Jiancheng 《Chinese Medicine and Culture》 CAS 2025年第1期50-60,共11页
Traditional Chinese medicine(TCM)has played a significant role in the prevention and treatment of chronic heart failure(CHF).To study TCM diagnosis of CHF,a total of 278 Chinese clinical research articles on the study... Traditional Chinese medicine(TCM)has played a significant role in the prevention and treatment of chronic heart failure(CHF).To study TCM diagnosis of CHF,a total of 278 Chinese clinical research articles on the study of CHF syndromes in recent 40 years retrieved from Web of Science,Scopus,Pub Med,Embase,CNKI,Wanfang Data,Cq VIP,and Sino Med.According to cumulative frequency analysis,network analysis,and hierarchical cluster analysis,the study found the distribution of CHF syndromes was syndrome of qi deficiency with blood stasis,syndrome of qi and yin deficiency,syndrome of yang deficiency with water flooding,syndrome of heart blood stasis obstruction,syndrome of turbid phlegm,and syndrome of collapse due to primordial yang deficiency.The syndrome elements on location of illness were heart,kidney,lung,and spleen.The syndrome elements on nature of illness were qi deficiency,blood stasis,yang deficiency,yin deficiency,water retention,and turbid phlegm.These findings can provide reference to the research on diagnosis and treatment of CHF,and contribute to the study on syndrome standardization and objective research of TCM diagnosis. 展开更多
关键词 Chronic heart failure Traditional Chinese medicine Hierarchical cluster analysis Network analysis Syndrome Syndrome differentiation Syndrome element
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Profiling Brazil's research elite:Insights from a cluster analysis of a large database 认领 引用
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作者 Cristian Rogério Foguesatto Denis Borenstein +1 位作者 Marcelo Perlin Takeyoshi Imasato 《Journal of Data and Information Science》 CSCD 2025年第3期183-198,共16页
Purpose:This study analyzes the profiles of elite Brazilian researchers,recognized through the prestigious CNPq productivity scholarships.By identifying distinct researcher clusters,the study sheds light on different ... Purpose:This study analyzes the profiles of elite Brazilian researchers,recognized through the prestigious CNPq productivity scholarships.By identifying distinct researcher clusters,the study sheds light on different academic strategies,levels of productivity,and academic contributions within the Brazilian higher education system.Design/methodology/approach:The research analyzes a comprehensive dataset of 14,003 researchers,employing principal component analysis(PCA)followed by cluster analysis to group researchers based on their academic attributes.The clusters reflect diverse aspects of research productivity,graduate supervisions,and publication patterns.Findings:The analysis reveals the existence of three distinct researcher profiles(the Advanced Supervisors,the Book Publishers/Organizers,and the Generalists).The study also highlights the characteristics of highcaliber scientists,representing the upper echelon of Brazilian researchers in terms of productivity and impact.Research limitations:Although the study provides a robust analysis of the Brazilian system,the results reflect specific characteristics of the Brazilian academic context.Furthermore,the analysis was restricted to normalized annual data,which may overlook temporal variations in researcher productivity.Pratical implications:The findings provide valuable insights for policy makers,funding agencies(such as CNPq),and university administrators who aim to develop tailored support programs for different researcher profiles.Originality/value:The cluster-based profiling offers a novel perspective on how different academic trajectories coexist within a national science system,offering lessons for other emerging economies. 展开更多
关键词 Elite researchers Cluster analysis Research productivity Lattes Citations Principal component analysis
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Roles of Digital Technology in Assessment Within Context of STEAM Education:A Visualized Literature Review Based on Cluster Analysis 认领 引用
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作者 TAN Xiyue 《US-China Education Review(A)》 2025年第7期510-525,共16页
As STEAM education becomes increasingly prevailing,the integration of digital technologies into assessment practices turned out to be critical domain of research.This study conducts a visualized literature review to i... As STEAM education becomes increasingly prevailing,the integration of digital technologies into assessment practices turned out to be critical domain of research.This study conducts a visualized literature review to investigate how digital technologies contribute to assessment in various contexts,concentrating on four crucial thematic domains:learning motivation,assessment complexity,assessment literacy,and the range of constructs.Through the analysis of publications from Web of Science Core Collection by CiteSpace,this review identifies multifaced roles of digital assessment in pedagogical practices.A conceptual framework is proposed to illustrate the interrelated roles.Therefore,this research attempts to provide an overarching viewpoint of the integration of digital assessment in educational settings based on cluster and keyword analysis from WoS publications. 展开更多
关键词 visualized cluster analysis digital assessment digital technologies STEAM education
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Mathematical Tools of Cluster Analysis 认领 引用 被引量：6
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作者 Peter Trebuna Jana Halcinova 《Applied Mathematics》 2013年第5期814-816,共3页
The paper deals with cluster analysis and comparison of clustering methods. Cluster analysis belongs to multivariate statistical methods. Cluster analysis is defined as general logical technique, procedure, which allo... The paper deals with cluster analysis and comparison of clustering methods. Cluster analysis belongs to multivariate statistical methods. Cluster analysis is defined as general logical technique, procedure, which allows clustering variable objects into groups-clusters on the basis of similarity or dissimilarity. Cluster analysis involves computational procedures, of which purpose is to reduce a set of data on several relatively homogenous groups-clusters, while the condition of reduction is maximal and simultaneously minimal similarity of clusters. Similarity of objects is studied by the degree of similarity (correlation coefficient and association coefficient) or the degree of dissimilarity-degree of distance (distance coefficient). Methods of cluster analysis are on the basis of clustering classified as hierarchical or non-hierarchical methods. 展开更多
关键词 Cluster Analysis Hierarchical Cluster Analysis Methods Non-Hierarchical Cluster Analysis Methods
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Group decision-making method based on entropy and experts cluster analysis 认领 引用 被引量：17
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作者 Xuan Zhou Fengming Zhang +1 位作者 Xiaobin Hui Kewu Li 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第3期468-472,共5页
According to the aggregation method of experts'evaluation information in group decision-making,the existing methods of determining experts'weights based on cluster analysis take into account the expert's p... According to the aggregation method of experts'evaluation information in group decision-making,the existing methods of determining experts'weights based on cluster analysis take into account the expert's preferences and the consistency of expert's collating vectors,but they lack of the measure of information similarity.So it may occur that although the collating vector is similar to the group consensus,information uncertainty is great of a certain expert.However,it is clustered to a larger group and given a high weight.For this,a new aggregation method based on entropy and cluster analysis in group decision-making process is provided,in which the collating vectors are classified with information similarity coefficient,and the experts'weights are determined according to the result of classification,the entropy of collating vectors and the judgment matrix consistency.Finally,a numerical example shows that the method is feasible and effective. 展开更多
关键词 group decision-making judgment matrix entropy information similarity coefficient cluster analysis.
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Clinical heterogeneity in patients with early-stage Parkinson’s disease:a cluster analysis 认领 引用 被引量：8
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作者 Ping LIU Tao FENG +2 位作者 Yong-jun WANG Xuan ZHANG Biao CHEN 《Journal of Zhejiang University-SCIENCE B》 SCIE CAS CSCD 2011年第9期694-703,共10页
The aim of this study was to investigate the clinical heterogeneity of Parkinson's disease(PD) among a cohort of Chinese patients in early stages.Clinical data on demographics,motor variables,motor phenotypes,dise... The aim of this study was to investigate the clinical heterogeneity of Parkinson's disease(PD) among a cohort of Chinese patients in early stages.Clinical data on demographics,motor variables,motor phenotypes,disease progression,global cognitive function,depression,apathy,sleep quality,constipation,fatigue,and L-dopa complications were collected from 138 Chinese PD subjects in early stages(Hoehn and Yahr stages 1-3).The PD subject subtypes were classified using k-means cluster analysis according to the clinical data from five-to three-cluster consecutively.Kappa statistical analysis was performed to evaluate the consistency among different subtype solutions.The cluster analysis indicated four main subtypes:the non-tremor dominant subtype(NTD,n=28,20.3%),rapid disease progression subtype(RDP,n=7,5.1%),young-onset subtype(YO,n=50,36.2%),and tremor dominant subtype(TD,n=53,38.4%).Overall,78.3%(108/138) of subjects were always classified between the same three groups(52 always in TD,7 in RDP,and 49 in NTD),and 98.6%(136/138) between five-and four-cluster solutions.However,subjects classified as NTD in the four-cluster analysis were dispersed into different subtypes in the three-cluster analysis,with low concordance between four-and three-cluster solutions(kappa value= 0.139,P=0.001).This study defines clinical heterogeneity of PD patients in early stages using a data-driven approach.The subtypes generated by the four-cluster solution appear to exhibit ideal internal cohesion and external isolation. 展开更多
关键词 Parkinson＇s disease Heterogeneity Subtype Cluster analysis
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Cluster analysis on summer precipitation field over Qinghai-Tibet Plateau from 1961 to 2004 认领 引用 被引量：8
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作者 LU Heli SHAO Quanqin +3 位作者 LIU Jiyuan WANG Junbang CHEN Shenbin CHEN Zhuoqi 《Journal of Geographical Sciences》 SCIE 2008年第3期295-307,共13页
The summer day-by-day precipitation data of 97 meteorological stations on the Qinghai-Tibet Plateau from 1961 to 2004 were selected to analyze the temporal-spatial distribution through accumulated variance,correlation... The summer day-by-day precipitation data of 97 meteorological stations on the Qinghai-Tibet Plateau from 1961 to 2004 were selected to analyze the temporal-spatial distribution through accumulated variance,correlation analysis,regression analysis,empirical orthogonal function,power spectrum function and spatial analysis tools of GIS.The result showed that summer precipitation occupied a relatively high proportion in the area with less annual precipitation on the Plateau and the correlation between summer precipitation and annual precipitation was strong.The altitude of these stations and summer precipitation tendency presented stronger positive correlation below 2000 m,with correlation value up to 0.604（α=0.01）.The subtracting tendency values between 1961-1983 and 1984-2004 at five altitude ranges（2000-2500 m,2500-3000 m,3500-4000 m,4000-4500 m and above 4500 m）were above zero and accounted for 71.4%of the total.Using empirical orthogonal function, summer precipitation could be roughly divided into three precipitation pattern fields：the Southeast Plateau Pattern Field,the Northeast Plateau Pattern field and the Three Rivers＇ Headstream Regions Pattern Field.The former two ones had a reverse value from the north to the south and opposite line was along 35°N.The potential cycles of the three pattern fields were 5.33a,21.33a and 2.17a respectively,tested by the confidence probability of 90%.The station altitudes and summer precipitation potential cycles presented strong negative correlation in the stations above 4500 m,with correlation value of-0.626（α=0.01）.In Three Rivers Headstream Regions summer precipitation cycle decreased as the altitude rose in the stations above 3500 m and increased as the altitude rose in those below 3500 m.The empirical orthogonal function analysis in June precipitation,July precipitation and August precipitation showed that the June precipitation pattern field was similar to the July＇s,in which southern Plateau was positive and northern Plateau negative.But positive value area in July precipitation pattern field was obviously less than June＇s.The August pattern field was totally opposite to June＇s and July＇s.The positive area in August pattern field jumped from the southern Plateau to the northern Plateau. 展开更多
关键词 Qinghai-Tibet Plateau summer precipitation cluster analysis precipitation pattern field precipitation cycle
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Cluster Analysis on Japonica Rice(Oryza sativa L.) with Good Eating Quality Based on SSR Markers and Phenotypic Traits 认领 引用 被引量：6
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作者 ZHANG Chun-hong LI Jin-zhou +3 位作者 ZHU Zhen ZHANG Ya-dong ZHAO Ling WANG Cai-lin 《Rice science》 2010年第2期111-121,共11页
Diversity of 60 conventional japonica rice accessions with good eating quality at home and abroad was analyzed using SSR molecular markers, agronomic traits and taste characteristics. A total of 290 alleles were detec... Diversity of 60 conventional japonica rice accessions with good eating quality at home and abroad was analyzed using SSR molecular markers, agronomic traits and taste characteristics. A total of 290 alleles were detected in the 60 accessions at 72 SSR loci with the high similarity coefficients varying between 0.600 and 0.924. The loci on chromosome 5 showed the greatest value in average allele number. Additionally, most of the SSR loci could detect 3 to 4 alleles. An UPGMA dendrogram based on the cluster analysis of the genetic similarity coefficients showed that the grouping trend of part of the rice accessions was geographic-related and most of the rice accessions in Jiangsu Province, China were clustered together. Furthermore, many domestic accessions from south and north origins in China were close to the foreign japonica rice varieties, as proved by their pedigree origin from the foreign high-quality sources. For taste characteristics, part of the accessions with excellent taste were clearly clustered into one category though they came from different geographical regions, which indicates that taste characteristics of some varieties were mainly genetically determined. In addition, the agronomic traits of japonica rice with good taste might be closely related with their geographical origins, but the relationship between superior taste characteristics and agronomic traits should be further clarified. 展开更多
关键词 japonica rice simple sequence repeat marker cluster analysis phenotypic traits taste characteristics genetic diversity
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Bohai crude oil identification by gas chromatogram fingerprinting quantitative analysis coupled with cluster analysis 认领 引用 被引量：5
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作者 SUN Peiyan BAO Mutai +5 位作者 GAO Zhenhui LI Mei ZHAO Yuhui WANG Xinping ZHOU Qing WANG Xiulin 《Acta Oceanologica Sinica》 SCIE CAS 2006年第5期55-62,共8页
By gas chromatogram, six crude oils fingerprinting distributed in four oilfields and four oil platforms were analyzed and the corre- sponding normal paraffin hydrocarbon （ including pristane and phytane） concentrati... By gas chromatogram, six crude oils fingerprinting distributed in four oilfields and four oil platforms were analyzed and the corre- sponding normal paraffin hydrocarbon （ including pristane and phytane） concentration was obtained by the internal standard methed. The normal paraffin hydrocarbon distribution patterns of six crude oils were built and compared. The cluster analysis on the normal paraffin hydrocarbon concentration was conducted for classification and some ratios of oils were used for oils comparison. The results indicated： there was a clear difference within different crude oils in different oil fields and a small difference between the crude oils in the same oil platform. The normal paraffin hydrocarbon distribution pattern and ratios, as well as the cluster analysis on the nomad paraffin hydrocarbon concentration can have a better differentiation result for the crude oils with small difference than the original gas chromatogram. 展开更多
关键词 oil fingerprinting identification gas chromatogram normal paraffin hydrocarbons distribution pattern ratio cluster analysis
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Regional Allocation of CO_2 Intensity Reduction Targets Based on Cluster Analysis 认领 引用 被引量：11
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作者 YANG Yuan CAI Wen-Jia +1 位作者 WANG Can WANG Si-Qiang 《Advances in Climate Change Research》 2012年第4期220-228,共9页
To meet China＇s CO2 intensity target of 40%-45% reduction by 2020 based on the 2005 level, a regional allocation method based on cluster analysis is developed. Thirty Chinese provinces are classified into six groups ... To meet China＇s CO2 intensity target of 40%-45% reduction by 2020 based on the 2005 level, a regional allocation method based on cluster analysis is developed. Thirty Chinese provinces are classified into six groups based on economy, emissions, and reduction potential indicators. Under the equity principle, the two most developed groups axe assigned the highest reduction targets （55% and 65%, respectively）. However, their reduction potent!al is limited. Under the efficiency principle, the two groups with the highest reduction potential take the highest targets （48% and 61%, respectively）, but their economy is relatively backward. When equity and efficiency are equally weighted, the 5th group with a prominent reduction potential takes the highest target （54%）, and the 2nd and the 3rd groups with large industry scales take the second highest target （49%）. However, under all the three allocation schemes, the targets are not greater than 40% for the 4th and the 6th groups, which have a relatively low economic ability, emissions, and reduction potential. Due to inconsistency between economic and reduction potential, corresponding market mechanisms and policy instruments should be established to ensure equity and efficiency of regional target allocation. 展开更多
关键词 C02 intensity reduction targets allocation cluster analysis regional difference
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A New Species of Cupressinocladus from the Lower Cretaceous of Guyang Basin,Inner Mongolia,China and Cluster Analysis 认领 引用 被引量：3
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作者 JIN Peihong MAO Teng +5 位作者 DONG Junling WANG Zixi SUN Mingxuan XU Xiaohui DU Baoxia SUN Bainian 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第4期1200-1214,共15页
Cupressinocladus Seward is a fossil genus of conifers and conifer fossils with reproductive organs are very rare. In general, it is difficult to understand the natural affinities with other conifers. In this paper, a ... Cupressinocladus Seward is a fossil genus of conifers and conifer fossils with reproductive organs are very rare. In general, it is difficult to understand the natural affinities with other conifers. In this paper, a new species, Cupressinocladus guyangensis P.H. Jin et B.N. Sun sp. nov., is reported based on branches with immature female cones from the Lower Cretaceous Guyang Formation of the Guyang Basin in Inner Mongolia, northern China. The foliage shoots are decussate. Leaves are decussate, imbricate, scale-like, weakly dimorphic, and bear longitudinal glands on the abaxial view. Stomata complexes are haplocheilic, monocyclic, irregularly arranged, and spread along the leaf margin. Immature female cones are subglobose with 6-8 cone scales, and three subglobose ovules arranged in a row at the base of the cone scales. Moreover, we performed cluster analysis using a statistics and machine learning toolbox for 23 fossils and extant species based on 16 morphological characters. The result implies that the new species bears a close resemblance to the extant Cupressusfunebris Endl. and might have nearest systematic affinities to it. 展开更多
关键词 Cupressinocladus Immature female cone Lower Cretaceous Cluster analysis New species
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Chinese family care patterns of childhood rheumatic diseases:A cluster analysis 认领 引用 被引量：3
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作者 Jiali Ma Qinglin Yu +1 位作者 Taomei Zhang Ying Zhang 《International Journal of Nursing Sciences》 CSCD 2020年第1期41-48,共8页
Objectives:The purpose is to distinguish family care(FC)patterns of childhood rheumatic diseases in Chinese families and to determine the predictors of FC patterns.Methods:This secondary analysis contained two cross-s... Objectives:The purpose is to distinguish family care(FC)patterns of childhood rheumatic diseases in Chinese families and to determine the predictors of FC patterns.Methods:This secondary analysis contained two cross-section surveys with a convenient sample of totally 398 caregivers who have a child with rheumatic diseases from four pediatric hospitals.Caregivers were required to completed Family Management Measure questionnaire.Cluster analysis was used to distinguish patterns and multinomial logistic regression analysis was used to find predictors.Results:Four patterns were identified:the normal-perspective and collaborative(28.4%),the effortless and contradictory(24.6%),the chaotic and strenuous(18.3%),and the confident and concerning(28.7%).Disease category(x2=21.23,P=0.002),geographic location(x2=8.41,P=0,038),maternal educational level(x2=12.69,P=0.048)and family monthly income(x2=33.21,P<0.001)predicted different patterns.Conclusions:FC patterns were different among families.Disease-related and family-related factors were vital predictors to distinguish patterns consistent with the Family Management Style Framework.The result assisted that clinicians recognize FC patterns and predictors effectively to provide tailored advice in time. 展开更多
关键词 Child Cluster analysis Cross-sectional studies Family caregivers Pediatric hospitals Rheumatic diseases
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Classification of Rice Materials for Drought Resistance by Cluster Analysis 认领 引用 被引量：9
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作者 严明建 黄文章 +3 位作者 胡景涛 吕直文 雷树凡 黄成志 《Agricultural Science & Technology》 CAS 2010年第4期94-97,共4页
Under drought treatment conditions,102 shares of different rice（Oryza sativa） varieties were clustered using the agronomic traits including productive ears,grains per ear,1 000-grain weight,plant height and grain we... Under drought treatment conditions,102 shares of different rice（Oryza sativa） varieties were clustered using the agronomic traits including productive ears,grains per ear,1 000-grain weight,plant height and grain weight per plant as indicators.The results showed that the materials tested could be classified into 5 groups.Of the five groups,group Ⅴ showed highest drought resistance（mean Dc value reached 84.88）,and could therefore be used as parent materials for drought cultivar breeding;groupⅡexhibited a mean Dc value of 75.64,among these materials some individuals performed excellent traits and could be used as special materials;group Ⅳ showed the lowest mean Dc value（45.9）,indicating no drought resistance;groupⅠand group Ⅲ performed as ordinary. 展开更多
关键词 Oryza sativa Drought resistance Cluster analysis Classification
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Identifying a competency improvement strategy for infection prevention and control professionals:A rapid systematic review and cluster analysis 认领 引用 被引量：4
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作者 Nuo Chen Shunning Li +3 位作者 Zhengling Kuang Ting Gong Weilong Zhou Ying Wang 《Health Care Science》 2024年第1期53-66,共14页
Remarkable progress has been made in infection prevention and control(IPC)in many countries,but some gaps emerged in the context of the coronavirus disease 2019(COVID-19)pandemic.Core capabilities such as standard cli... Remarkable progress has been made in infection prevention and control(IPC)in many countries,but some gaps emerged in the context of the coronavirus disease 2019(COVID-19)pandemic.Core capabilities such as standard clinical precautions and tracing the source of infection were the focus of IPC in medical institutions during the pandemic.Therefore,the core competences of IPC professionals during the pandemic,and how these contributed to successful prevention and control of the epidemic,should be studied.To investigate,using a systematic review and cluster analysis,fundamental improvements in the competences of infection control and prevention professionals that may be emphasized in light of the COVID-19 pandemic.We searched the PubMed,Embase,Cochrane Library,Web of Science,CNKI,WanFang Data,and CBM databases for original articles exploring core competencies of IPC professionals during the COVID-19 pandemic(from January 1,2020 to February 7,2023).Weiciyun software was used for data extraction and the Donohue formula was followed to distinguish high-frequency technical terms.Cluster analysis was performed using the within-group linkage method and squared Euclidean distance as the metric to determine the priority competencies for development.We identified 46 studies with 29 high-frequency technical terms.The most common term was“infection prevention and control training”(184 times,17.3%),followed by“hand hygiene”(172 times,16.2%).“Infection prevention and control in clinical practice”was the most-reported core competency(367 times,34.5%),followed by“microbiology and surveillance”(292 times,27.5%).Cluster analysis showed two key areas of competence:Category 1(program management and leadership,patient safety and occupational health,education and microbiology and surveillance)and Category 2(IPC in clinical practice).During the COVID-19 pandemic,IPC program management and leadership,microbiology and surveillance,education,patient safety,and occupational health were the most important focus of development and should be given due consideration by IPC professionals. 展开更多
关键词 infection prevention and control professionals competency improvement cluster analysis COVID-19 review
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Cluster analysis of the domain of microseismic event attributes for fl oor water inrush warning in the working face 认领 引用 被引量：3
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作者 Shang Guo-Jun Liu Xiao-Fei +3 位作者 Li Li Zhao Li-Song Shen Jin-Song Huang Wei-Lin 《Applied Geophysics》 SCIE CSCD 2022年第3期409-423,471,472,共15页
Differences are found in the attributes of microseismic events caused by coal seam rupture,underground structure activation,and groundwater movement in coal mine production.Based on these differences,accurate classific... Differences are found in the attributes of microseismic events caused by coal seam rupture,underground structure activation,and groundwater movement in coal mine production.Based on these differences,accurate classification and analysis of microseismic events are important for the water inrush warning of the coal mine working facefloor.Cluster analysis,which classifies samples according to data similarity,has remarkable advantages in nonlinear classification.A water inrush early warning method for coal minefloors is proposed in this paper.First,the short time average over long time average(STA/LTA)method is used to identify effective events from continuous microseismic records to realize the identification of microseismic events in coal mines.Then,ten attributes of microseismic events are extracted,and cluster analysis is conducted in the attribute domain to realize unsupervised classification of microseismic events.Clustering results of synthetic andfield data demonstrate the effectiveness of the proposed method.The analysis offield data clustering results shows that thefirst kind of events with time change rules is of considerable importance to the early warning of water inrush from the coal mine working facefloor. 展开更多
关键词 signal detection attribute extraction cluster analysis and water disaster warning
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Characterizing heterogeneity in vehicular traffic speed using two-step cluster analysis 认领 引用 被引量：4
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作者 潘义勇 孙璐 《Journal of Southeast University(English Edition)》 EI CAS 2012年第4期480-484,共5页
In order to analyze the heterogeneity in vehicular traffic speed, a new method that integrates cluster analysis and probability distribution function fitting is presented. First, for identifying the optimal number of ... In order to analyze the heterogeneity in vehicular traffic speed, a new method that integrates cluster analysis and probability distribution function fitting is presented. First, for identifying the optimal number of clusters, the two-step cluster method is applied to analyze actual speed data, which suggests that dividing speed data into two clusters can best reflect the intrinsic patterns of traffic flows. Such information is then taken as guidance in probability distribution function fitting. The normal, skew-normal and skew-t distribution functions are used to fit the probability distribution of each cluster respectively, which suggests that the skew-t distribution has the highest fitting accuracy; the second is skew-normal distribution; the worst is normal distribution. Model analysis results demonstrate that the proposed mixture model has a better fitting and generalization capability than the conventional single model. In addition, the new method is more flexible in terms of data fitting and can provide a more accurate model of speed distribution. 展开更多
关键词 speed distribution heterogeneity mixture model cluster analysis
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Variation and Cluster Analysis on Leaf Characters from Different Provenance Sources of Polygonum multiflorum Thunb 认领 引用 被引量：2
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作者 韦艳梅 王凌晖 +2 位作者 曹福亮 韦山青 梁耀丹 《Agricultural Science & Technology》 CAS 2010年第6期94-98,共5页
[Objective] The aim was to study the variation of leaf characters from different provenance sources of Polygonum multiflorum Thunb,as well as to carry out cluster analysis on P.multiflorum from different provenance so... [Objective] The aim was to study the variation of leaf characters from different provenance sources of Polygonum multiflorum Thunb,as well as to carry out cluster analysis on P.multiflorum from different provenance sources to provide basis for the classification,identification,breeding and improved variety selection of P.multiflorum.[Method] Leaf shape characters of 31 copies of germplasm resources in the major distribution region of the whole country were determined,and the genetic variation of P.multiflorum leaves from different producing areas was analyzed.[Result] The leaf characters of single plant of the same experimental provenance source of P.multiflorum were relatively stable,the variation was mainly found on the single leaf area,1/2 leaf width,leaf width and other indicators;the variation of each leaf character among different provenance sources was obvious,and the variation was mainly found on the single leaf weight,leaf area,1/2 leaf width,leaf length and other indicators.The correlation analysis of each leaf character in P.multiflorum suggested that the single leaf area and single leaf weight showed extremely significant positive correlation with leaf length,1/2 leaf width,leaf width,leaf thickness and leaf stem length,while the single leaf area and single leaf weight showed significant negative correlation with WWR（leaf width/1/2 leaf width）and LWR（leaf length/1/2 leaf length）,in addition,several macroscopic leaf characters such as leaf length,1/2 leaf width,leaf width,leaf stem length showed extremely positive correlation.The main component analysis result suggested that the contribution rate of accumulation variance of the front three main components was up to 97.4%,which could better reflect the comprehensive performance of leaf characters of different provenance sources of P.multiflorum.The cluster analysis showed that the experimental 31 copies of P.multiflorum provenance sources should be divided into three classes,the first class was distributed in the Middle,Western of Guizhou,northwestern of Guangxi and western areas with higher altitude;the second class was distributed in Hunan,Hubei,Sichuan,Guangdong and the most area of Guangxi;the third class was distributed in Anhui,Jiangsu and Henan and Shandong.[Conclusion] Cluster analysis of leaf characters indicated that the kinds of provenance sources which the geographical position was closer could be got together.The study had provided a certain basis for the classification of P.multiflorum. 展开更多
关键词 Polygonum multiflorum Thunb Leaf characters Variation Cluster analysis
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ARHCS (Automatic Rainfall Half-Life Cluster System): A Landslides Early Warning System (LEWS) Using Cluster Analysis and Automatic Threshold Definition 认领 引用 被引量：2
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作者 Cassiano Antonio Bortolozo Luana Albertani Pampuch +8 位作者 Marcio Roberto Magalhães De Andrade Daniel Metodiev Adenilson Roberto Carvalho Tatiana Sussel Gonçalves Mendes Tristan Pryer Harideva Marturano Egas Rodolfo Moreda Mendes Isadora Araújo Sousa Jenny Power 《International Journal of Geosciences》 CAS 2024年第1期54-69,共16页
A significant portion of Landslide Early Warning Systems (LEWS) relies on the definition of operational thresholds and the monitoring of cumulative rainfall for alert issuance. These thresholds can be obtained in vari... A significant portion of Landslide Early Warning Systems (LEWS) relies on the definition of operational thresholds and the monitoring of cumulative rainfall for alert issuance. These thresholds can be obtained in various ways, but most often they are based on previous landslide data. This approach introduces several limitations. For instance, there is a requirement for the location to have been previously monitored in some way to have this type of information recorded. Another significant limitation is the need for information regarding the location and timing of incidents. Despite the current ease of obtaining location information (GPS, drone images, etc.), the timing of the event remains challenging to ascertain for a considerable portion of landslide data. Concerning rainfall monitoring, there are multiple ways to consider it, for instance, examining accumulations over various intervals (1 h, 6 h, 24 h, 72 h), as well as in the calculation of effective rainfall, which represents the precipitation that actually infiltrates the soil. However, in the vast majority of cases, both the thresholds and the rain monitoring approach are defined manually and subjectively, relying on the operators’ experience. This makes the process labor-intensive and time-consuming, hindering the establishment of a truly standardized and rapidly scalable methodology on a large scale. In this work, we propose a Landslides Early Warning System (LEWS) based on the concept of rainfall half-life and the determination of thresholds using Cluster Analysis and data inversion. The system is designed to be applied in extensive monitoring networks, such as the one utilized by Cemaden, Brazil’s National Center for Monitoring and Early Warning of Natural Disasters. 展开更多
关键词 Landslides Early Warning System (LEWS) Cluster Analysis Landslides Brazil
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Principal Component Analysis and Cluster Analysis of Fagopyrum tataricum Varieties(Lines) 认领 引用 被引量：3
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作者 赵建栋 李秀莲 +2 位作者 史兴海 陈稳良 高伟 《Agricultural Science & Technology》 CAS 2016年第12期2707-2712,共6页
In order to reveal the genetic differences and agronomic traits of Fagopy-rum tataricum_ varieties （lines） intuitively, explore good resources and avoid the blindness of parent selection during the breeding process,... In order to reveal the genetic differences and agronomic traits of Fagopy-rum tataricum_ varieties （lines） intuitively, explore good resources and avoid the blindness of parent selection during the breeding process, six primary agronomic traits of 45 F. tataricum_ varieties （lines） that came from the eleven buckwheat breeding departments across the country were analyzed with principal component analysis and cluster analysis. The results of principal component analysis showed that the six agronomic traits could be simplified into three principal components, and the cumulative contribution rate reached 83%. The results of cluster analysis showed that the 45 F. tataricum varieties （lines） were classified into four groups：high stalk, medium yield and smal grain type, medium stalk, high yield and large grain type, medium stalk, low yield and smal grain type and high stalk, medium yield and medium grain type. Among them, performance of comprehensive trait of the second type was better than that of the other types. Thus, the F. tataricum_va-rieties （lines） that were classified into the second type could be considered as good varieties （lines） or breeding materials. The genetic differences among F. tataricum_varieties （lines） had no necessary correlations with origin and geographical distance. ln addition to complementary traits and geographical distance, genetic distances （dif-ferent populations） should be taken into consideration during parent selection in cross breeding. 展开更多
关键词 Fagopyrum tataricum Agronomic traits Cluster analysis
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