期刊文献+
共找到30,042篇文章
< 1 2 250 >
每页显示 20 50 100
Genetic Diversity and Clustering Analysis of 48Cultivars of Olea euyopaea L. 被引量:1
1
作者 宁德鲁 陈少瑜 +4 位作者 陈海云 李瑞 李勇杰 毛云玲 吴涛 《Agricultural Science & Technology》 CAS 2013年第9期1215-1219,共5页
Inter-simple sequence repeat(ISSR) molecular markers were applied to analyze the genetic diversity and clustering of 48 introduced and bred cultivars of Olea euyopaea L. Totally 106 DNA bands were amplified by 11 sc... Inter-simple sequence repeat(ISSR) molecular markers were applied to analyze the genetic diversity and clustering of 48 introduced and bred cultivars of Olea euyopaea L. Totally 106 DNA bands were amplified by 11 screened primers, including 99 polymorphic bands; the percentage of polymorphic loci was 93.40%, indicating a rich genetic diversity in Olea euyopaea L. germplasm resources. Based on Nei's genetic distances between various cultivars, a dendrogram of 48 cultivars of Olea euyopaea L. was constructed using unweighted pair-group(UPMGA)method,which showed that 48 cultivars were clustered into four main categories; 84.6% of native cultivars were clustered into two categories; most of introduced cultivars were clustered based on their sources and main usages but not on their geographic origins. This study will provide references for the utilization and further genetic improvement of Olea euyopaea L. germplasm resources. 展开更多
关键词 Olea euyopaea L. Genetic diversity clustering analysis
下载PDF
Clustering analysis algorithm for security supervising data based on semantic description in coal mines 被引量:1
2
作者 孟凡荣 周勇 夏士雄 《Journal of Southeast University(English Edition)》 EI CAS 2008年第3期354-357,共4页
In order to mine production and security information from security supervising data and to ensure security and safety involved in production and decision-making,a clustering analysis algorithm for security supervising... In order to mine production and security information from security supervising data and to ensure security and safety involved in production and decision-making,a clustering analysis algorithm for security supervising data based on a semantic description in coal mines is studied.First,the semantic and numerical-based hybrid description method of security supervising data in coal mines is described.Secondly,the similarity measurement method of semantic and numerical data are separately given and a weight-based hybrid similarity measurement method for the security supervising data based on a semantic description in coal mines is presented.Thirdly,taking the hybrid similarity measurement method as the distance criteria and using a grid methodology for reference,an improved CURE clustering algorithm based on the grid is presented.Finally,the simulation results of a security supervising data set in coal mines validate the efficiency of the algorithm. 展开更多
关键词 semantic description clustering analysis algorithm similarity measurement
下载PDF
Clustering Analysis on Large Grained Brassica napus Materials Based on the Optimized ACGM Markers
3
作者 俎峰 李静 +6 位作者 罗延青 赵凯琴 马芳 陈苇 王敬乔 李劲峰 董云松 《Agricultural Science & Technology》 CAS 2012年第11期2265-2268,共4页
[Objective] This study aimed to develop ACGM markers for the clustering analysis of large grained Brassica napus materials. [Method] A total of 44 pairs of ACGM primers were designed according to 18 genes related to A... [Objective] This study aimed to develop ACGM markers for the clustering analysis of large grained Brassica napus materials. [Method] A total of 44 pairs of ACGM primers were designed according to 18 genes related to Arabidopsis grain development and their homologous rape EST sequences. After electrophoresis, 18 pairs of ACGM primers were selected for the clustering analysis of 16 larger grained samples and four fine grained samples of rapeseed. [Result] PCR result showed that 2-6 specific bands were respectively amplified by each pair of primes, and all the bands were polymorphic and repeatable, suggesting that the optimized ACGM markers were useful for clustering analysis of B. napus species. Clustering analysis revealed that the 20 rapeseed samples were divided into three clusters A, B, and C at similarity coefficient 0.6. Then, the clusters A and B were further divided into five sub clusters A1, A2, A3, B1 and B2 at similarity coefficient 0.67. [Conclusion] This study will provide theoretical and practical values for rape breeding. 展开更多
关键词 Brassica napus Large grain clustering analysis ACGM marker
下载PDF
Study on Trace Elements in Rehmannia glutinosa Libosch. by Principal Component Analysis and Clustering Analysis
4
作者 申明金 陈丽 曹洪斌 《Agricultural Science & Technology》 CAS 2013年第12期1764-1768,共5页
[Objective] This study aimed to investigate the trace elements in Rehman- nia glutinosa Libosch. by using principal component analysis and clustering analysis. [Method] Principal component analysis and clustering anal... [Objective] This study aimed to investigate the trace elements in Rehman- nia glutinosa Libosch. by using principal component analysis and clustering analysis. [Method] Principal component analysis and clustering analysis of R. glutinosa medicinal materials from different sources were conducted with contents of six trace elements as indices. [Result] The principal component analysis could comprehen- sively evaluate the quality of R. glutinosa samples with objective results which was consistent with the results of clustering analysis. [Conclusion] Principal component analysis and clustering analysis methods can be used for the quality evaluation of Chinese medicinal materials with multiple indices. 展开更多
关键词 Rehmannia glutinosa Libosch. (Radix Rehmanniae) Trace elements Principal component analysis clustering analysis
下载PDF
ARHCS (Automatic Rainfall Half-Life Cluster System): A Landslides Early Warning System (LEWS) Using Cluster Analysis and Automatic Threshold Definition
5
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
下载PDF
Comparative Analysis of Differences among Northern,Jiangnan,and Lingnan Classical Private Gardens Using Principal Component Cluster Method
6
作者 Lijuan Sun Hui Wang 《Journal of Architectural Research and Development》 2024年第5期20-29,共10页
This paper investigates the design essence of Chinese classical private gardens,integrating their design elements and fundamental principles.It systematically analyzes the unique characteristics and differences among ... This paper investigates the design essence of Chinese classical private gardens,integrating their design elements and fundamental principles.It systematically analyzes the unique characteristics and differences among classical private gardens in the Northern,Jiangnan,and Lingnan regions.The study examines nine classical private gardens from Northern China,Jiangnan,and Lingnan by utilizing the advanced tool of principal component cluster analysis.Based on literature analysis and field research,273 variables were selected for principal component analysis,from which four components with higher contribution rates were chosen for further study.Subsequently,we employed clustering analysis techniques to compare the differences among the three types of gardens.The results reveal that the first principal component effectively highlights the differences between Jiangnan and Lingnan private gardens.The second principal component serves as the key to defining the types of Northern private gardens and distinguishing them from the other two types,and the third principal component indicates that Lingnan private gardens can be categorized into two distinct types as well. 展开更多
关键词 Classical gardens Private gardens DIFFERENCES Principal component analysis cluster analysis
下载PDF
Clustering Structure Analysis in Time-Series Data With Density-Based Clusterability Measure 被引量:6
7
作者 Juho Jokinen Tomi Raty Timo Lintonen 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第6期1332-1343,共12页
Clustering is used to gain an intuition of the struc tures in the data.Most of the current clustering algorithms pro duce a clustering structure even on data that do not possess such structure.In these cases,the algor... Clustering is used to gain an intuition of the struc tures in the data.Most of the current clustering algorithms pro duce a clustering structure even on data that do not possess such structure.In these cases,the algorithms force a structure in the data instead of discovering one.To avoid false structures in the relations of data,a novel clusterability assessment method called density-based clusterability measure is proposed in this paper.I measures the prominence of clustering structure in the data to evaluate whether a cluster analysis could produce a meaningfu insight to the relationships in the data.This is especially useful in time-series data since visualizing the structure in time-series data is hard.The performance of the clusterability measure is evalu ated against several synthetic data sets and time-series data sets which illustrate that the density-based clusterability measure can successfully indicate clustering structure of time-series data. 展开更多
关键词 clustering EXPLORATORY data analysis time-series UNSUPERVISED LEARNING
下载PDF
Optimization of constitutive parameters of foundation soils k-means clustering analysis 被引量:7
8
作者 Muge Elif Orakoglu Cevdet Emin Ekinci 《Research in Cold and Arid Regions》 CSCD 2013年第5期626-636,共11页
The goal of this study was to optimize the constitutive parameters of foundation soils using a k-means algorithm with clustering analysis. A database was collected from unconfined compression tests, Proctor tests and ... The goal of this study was to optimize the constitutive parameters of foundation soils using a k-means algorithm with clustering analysis. A database was collected from unconfined compression tests, Proctor tests and grain distribution tests of soils taken from three different types of foundation pits: raft foundations, partial raft foundations and strip foundations. k-means algorithm with clustering analysis was applied to determine the most appropriate foundation type given the un- confined compression strengths and other parameters of the different soils. 展开更多
关键词 foundation soil regression model k-means clustering analysis
下载PDF
Unsupervised seismic facies analysis using sparse representation spectral clustering 被引量:4
9
作者 Wang Yao-Jun Wang Liang-Ji +3 位作者 Li Kun-Hong Liu Yu Luo Xian-Zhe Xing Kai 《Applied Geophysics》 SCIE CSCD 2020年第4期533-543,共11页
Traditional unsupervised seismic facies analysis techniques need to assume that seismic data obey mixed Gaussian distribution.However,fi eld seismic data may not meet this condition,thereby leading to wrong classifi c... Traditional unsupervised seismic facies analysis techniques need to assume that seismic data obey mixed Gaussian distribution.However,fi eld seismic data may not meet this condition,thereby leading to wrong classifi cation in the application of this technology.This paper introduces a spectral clustering technique for unsupervised seismic facies analysis.This algorithm is based on on the idea of a graph to cluster the data.Its kem is that seismic data are regarded as points in space,points can be connected with the edge and construct to graphs.When the graphs are divided,the weights of the edges between the different subgraphs are as low as possible,whereas the weights of the inner edges of the subgraph should be as high as possible.That has high computational complexity and entails large memory consumption for spectral clustering algorithm.To solve the problem this paper introduces the idea of sparse representation into spectral clustering.Through the selection of a small number of local sparse representation points,the spectral clustering matrix of all sample points is approximately represented to reduce the cost of spectral clustering operation.Verifi cation of physical model and fi eld data shows that the proposed approach can obtain more accurate seismic facies classification results without considering the data meet any hypothesis.The computing efficiency of this new method is better than that of the conventional spectral clustering method,thereby meeting the application needs of fi eld seismic data. 展开更多
关键词 seismic facies analysis spectral clustering sparse representation and unsupervised clustering
下载PDF
Evaluation and classification of residential greenbelt quality based on factor analysis & clustering analysis:An example of Xinxiang City,China 被引量:1
10
作者 乔丽芳 张毅川 齐安国 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第4期311-314,共4页
Five factors expressing greenbelt quality and one factor expressing quantity were adopted for evaluation of the residential greenbelt, and the AHP (Analytical Hierarchy Process) method was used to determine the valu... Five factors expressing greenbelt quality and one factor expressing quantity were adopted for evaluation of the residential greenbelt, and the AHP (Analytical Hierarchy Process) method was used to determine the value of factors. Thirty residential areas were selected as the samples. Two principal components were extracted and their expression was constructed by method of factor anlysis, therefore, quality evaluation of residential greenbelt was obtained. The accuracy of the function and implement quality classification toward the residential greenbelts in Xinxiang City were validated by clustering analysis method. The results showed that the greenbelt quality of fourteen residential areas was higher than the average level, of which eleven were newly-built residential areas. The 30 residential areas were classified into three types according to their greenbelt features and their formation by clustering analysis method. Finally rational proposal basing on aforesaid evaluating results was proposed for construction and renewal of residential greenbelt, upon which directive basis was provided for construction and renewal of residential greenbelt. 展开更多
关键词 residential area greenbelt quality EVALUATION factor analysis clustering analysis
下载PDF
Massive Power Device Condition Monitoring Data Feature Extraction and Clustering Analysis using MapReduce and Graph Model 被引量:4
11
作者 Hongtao Shen Peng Tao +1 位作者 Pei Zhao Hao Ma 《CES Transactions on Electrical Machines and Systems》 CSCD 2019年第2期221-230,共10页
Effective storage,processing and analyzing of power device condition monitoring data faces enormous challenges.A framework is proposed that can support both MapReduce and Graph for massive monitoring data analysis at ... Effective storage,processing and analyzing of power device condition monitoring data faces enormous challenges.A framework is proposed that can support both MapReduce and Graph for massive monitoring data analysis at the same time based on Aliyun DTplus platform.First,power device condition monitoring data storage based on MaxCompute table and parallel permutation entropy feature extraction based on MaxCompute MapReduce are designed and implemented on DTplus platform.Then,Graph based k-means algorithm is implemented and used for massive condition monitoring data clustering analysis.Finally,performance tests are performed to compare the execution time between serial program and parallel program.Performance is analyzed from CPU cores consumption,memory utilization and parallel granularity.Experimental results show that the designed framework and parallel algorithms can efficiently process massive power device condition monitoring data. 展开更多
关键词 clustering analysis GRAPH feature extraction MAPREDUCE maxcompute power device condition monitoring.
下载PDF
AN ANALYSIS OF THE APPLICABILITY OF FUZZY CLUSTERING IN ESTABLISHING AN INDEX FOR THE EVALUATION OF METEOROLOGICAL SERVICE SATISFACTION 被引量:1
12
作者 YAN Min-hui YAO Xiu-ping +2 位作者 WANG Lei JIANG Li-xia ZHANG Jin-feng 《Journal of Tropical Meteorology》 SCIE 2020年第1期103-110,共8页
An evaluation index is a prerequisite for the scientific evaluation of a public meteorological service.This paper aims to explore a technical method for determining and screening evaluation indicators.Based on public ... An evaluation index is a prerequisite for the scientific evaluation of a public meteorological service.This paper aims to explore a technical method for determining and screening evaluation indicators.Based on public satisfaction survey data obtained in Wafangdian,China in 2010,this study investigates the suitability of fuzzy clustering analysis method in establishing an evaluation index.Through quantitative analysis of multilayer fuzzy clustering of various evaluation indicators,correlation analysis indicates that if the results of clustering were identical for two evaluation indicators in the same sub-evaluation layer,then one indicator could be removed,or the two indicators merged.For evaluation indicators in different sub-evaluation layers,although clustering reveals attribute correlations,these indicators may not be substituted for one another.Analysis of the applicability of the fuzzy clustering method shows that it plays a certain role in the establishment and correction of an evaluation index. 展开更多
关键词 evaluation index multilayer fuzzy clustering analysis range transformation transitional closure method
下载PDF
The Bio-Geographical Regions Division of Global Terrestrial Animal by Multivariate Similarity Clustering Analysis Method 被引量:3
13
作者 Qi Shen Jiqi Lu +3 位作者 Shujie Zhang Zhixing You Yingdang Ren Xiaocheng Shen 《Open Journal of Ecology》 2022年第3期236-255,共20页
A novel multivariate similarity clustering analysis (MSCA) approach was used to estimate a biogeographical division scheme for the global terrestrial fauna and was compared against other widely used clustering algorit... A novel multivariate similarity clustering analysis (MSCA) approach was used to estimate a biogeographical division scheme for the global terrestrial fauna and was compared against other widely used clustering algorithms. The faunal dataset included almost all terrestrial and freshwater fauna, a total of 4631 families, 141,814 genera, and 1,334,834 species. Our findings demonstrated that suitable results were only obtained with the MSCA method, which was associated with distinct hierarchies, reasonable structuring, and furthermore, conformed to biogeographical criteria. A total of seven kingdoms and 20 sub-kingdoms were identified. We discovered that the clustering results for the higher and lower animals did not differ significantly, leading us to consider that the analysis result is convincing as the first zoogeographical division scheme for global all terrestrial animals. 展开更多
关键词 Global Animal Multivariate Similarity clustering analysis BIOGEOGRAPHY REGIONALIZATION
下载PDF
A NOVEL SVM ENSEMBLE APPROACH USING CLUSTERING ANALYSIS 被引量:2
14
作者 Yuan Hejin Zhang Yanning +2 位作者 Yang Fuzeng Zhou Tao Du Zhenhua 《Journal of Electronics(China)》 2008年第2期246-253,共8页
A novel Support Vector Machine(SVM) ensemble approach using clustering analysis is proposed. Firstly,the positive and negative training examples are clustered through subtractive clus-tering algorithm respectively. Th... A novel Support Vector Machine(SVM) ensemble approach using clustering analysis is proposed. Firstly,the positive and negative training examples are clustered through subtractive clus-tering algorithm respectively. Then some representative examples are chosen from each of them to construct SVM components. At last,the outputs of the individual classifiers are fused through ma-jority voting method to obtain the final decision. Comparisons of performance between the proposed method and other popular ensemble approaches,such as Bagging,Adaboost and k.-fold cross valida-tion,are carried out on synthetic and UCI datasets. The experimental results show that our method has higher classification accuracy since the example distribution information is considered during en-semble through clustering analysis. It further indicates that our method needs a much smaller size of training subsets than Bagging and Adaboost to obtain satisfactory classification accuracy. 展开更多
关键词 Support Vector Machine (SVM) ENSEMBLE clustering analysis
下载PDF
Optimization Study of Outburst Prevention Measures for Tuzhu Coal Mine Based on Fixed Weight Clustering Analysis 被引量:3
15
作者 Wenke Luo Shiliang Shi +3 位作者 Yi Lu Shenghua Zou Zaian Chen Liliang Chen 《Journal of Geoscience and Environment Protection》 2016年第1期153-161,共9页
Affected by many involved factors, different dimensions, data with large difference, incomplete information and so on, the most optimal selection of regional outburst prevention measures for outburst mine has become a... Affected by many involved factors, different dimensions, data with large difference, incomplete information and so on, the most optimal selection of regional outburst prevention measures for outburst mine has become a complicated system project. The traditional way of outburst prevention measure selection belongs to qualitative method, which may cause high-cost of gas control, huge quantities of drilling work, long construction time and even secondary disaster. To solve the above-mentioned problems, in light of occurrence status of coal seam gas in No. 21 mining area of Jinzhushan Tuzhu Mine, through grey fixed weight clustering theory and a combination method of qualitative and quantitative analysis, the judging model with multi-objective classification for optimization of outburst prevention measures was established. The three weight coefficients of outburst prevention technology scheme are sorted, in order to determine the advantages and disadvantages of each outburst prevention technology scheme under the comprehensive evaluation of multi-target. Finally, the problem of quantitative selection for regional outburst prevention technology scheme is solved under the situation of multi-factor mode and incomplete information, which provides reasonable and effective technical measures for prevention of coal and gas outburst disaster. 展开更多
关键词 Coal-Gas Outburst Grey Theory Fixed Weight clustering analysis Regional Outburst Prevention Measures
下载PDF
Co-word clustering analysis for nursing safety management research focuses by PubMed 被引量:1
16
作者 Yong-Hong Deng Xue-Yun Hao +1 位作者 Hui Zhang Guo-Min Song 《TMR Integrative Nursing》 2018年第3期108-114,共7页
Objective: To analyze hot research areas and the present research status of nursing safety management in PubMed. Methods: PubMed was searched using "safety management" for the literature on nursing safety manageme... Objective: To analyze hot research areas and the present research status of nursing safety management in PubMed. Methods: PubMed was searched using "safety management" for the literature on nursing safety management. BICOMB 2.0 and SPSS 20.0 software were used to analyze high-frequency keywords and conduct co-word clustering analysis. Results: We searched for totally 2353 articles related to our topic and extracted 19 high-frequency keywords (27.50%). Five research focuses were concluded, including: study on nursing safety culture; team work to promote nursing safety; practice of nursing safety management; workplace violence against nursing staffs; nursing safety and quality evaluation standard. Conclusion: Analysis of the hotspots of nursing safety management in the past 10 years will contribute to understanding the research emphases and trend of development, and provide reference for the study and practice of nursing safety management. 展开更多
关键词 Nursing safety management cluster analysis Co-word analysis Research focus
下载PDF
Research and Application on Spark Clustering Algorithm in Campus Big Data Analysis 被引量:1
17
作者 Qing Hou Guangjian Wang +2 位作者 Xiaozheng Wang Jiaxi Xu Yang Xin 《Journal of Computer Science Research》 2020年第1期16-20,共5页
Big data analysis has penetrated into all fields of society and has brought about profound changes.However,there is relatively little research on big data supporting student management regarding college and university... Big data analysis has penetrated into all fields of society and has brought about profound changes.However,there is relatively little research on big data supporting student management regarding college and university’s big data.Taking the student card information as the research sample,using spark big data mining technology and K-Means clustering algorithm,taking scholarship evaluation as an example,the big data is analyzed.Data includes analysis of students’daily behavior from multiple dimensions,and it can prevent the unreasonable scholarship evaluation caused by unfair factors such as plagiarism,votes of teachers and students,etc.At the same time,students’absenteeism,physical health and psychological status in advance can be predicted,which makes student management work more active,accurate and effective. 展开更多
关键词 SPARK clustering algorithm Big data Data analysis Mllib
下载PDF
Clustering Analysis of Distributional Patterns of Global Terrestrial Mammal 被引量:1
18
作者 Shen Xiaocheng Lu Jiqi +3 位作者 Shen Qi Ren Yingdang Liu Xintao Zhang Shujie 《Journal of Environmental Science and Engineering(B)》 2022年第4期97-110,共14页
In this study,the world’s land(except Antarctica)is divided into 67 basic geographical units according to ecological types.Using our newly proposed MSCA(Multivariate Similarity Clustering Analysis)method,7,591 specie... In this study,the world’s land(except Antarctica)is divided into 67 basic geographical units according to ecological types.Using our newly proposed MSCA(Multivariate Similarity Clustering Analysis)method,7,591 species of modern terrestrial mammals belonging to 1,374 genera in 162 families and 2,378 species of mammals in the Wallace era before 1876 are quantitatively analyzed,and almost the same clustering results are obtained,with clear levels and reasonable clustering,which conform to the principles of geography,statistics,ecology and biology.It not only affirms and supports the reasonable kernel of Wallace’s scheme,but also puts forward suggestions that should be revised and improved.The large or small differences between the clustering results and the mammalian geographical zoning schemes of contemporary scholars are caused by different analysis methods,and they are highly consistent with the analysis results of chordates,angiosperms and insects in the world analyzed by the same method.Once again,it confirms the homogeneity of the global biological distribution pattern of major groups,and the possibility of building a unified biogeographic zoning system in the world. 展开更多
关键词 Terrestrial mammals DISTRIBUTION cluster analysis geographical division
下载PDF
Estimation of Standard Operation Time of Flight Legs Based on Clustering and Probability Analysis
19
作者 Yuan Ligang Hu Minghua +1 位作者 Xie Hua Li Yinfeng 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2016年第4期491-501,共11页
A clustering algorithm and a probability statistics method were applied to different phases of a flight to analyze operation time during aircraft ground taxiing and airborne flight.And the clustering pattern,distribut... A clustering algorithm and a probability statistics method were applied to different phases of a flight to analyze operation time during aircraft ground taxiing and airborne flight.And the clustering pattern,distribution characteristics and dynamically changing rules of the two phases were identified.Further,an estimate method was established to measure operation time of flight legs,with creative steps of calculating individual segment separately and then integrating them accordingly.The method can both objectively and dynamically measure operation time,and accurately reflect real situation.It helps to better utilize airport slot resources and provides a strong support for air traffic flow management when scheduling flight plan in strategic and pre-tactic phases. 展开更多
关键词 flight leg standard operation time clustering probability analysis
下载PDF
Research status and hotspots of economic evaluation in nursing by co-word clustering analysis
20
作者 Yao-Ji Liao Guo-Zhen Gao 《Frontiers of Nursing》 CAS 2019年第3期233-239,共7页
Objective:The aim of this study is to discover research status and hotspots of economic evaluation(EE)in nursing area using co-word cluster analysis.Methods:Medical Subject Heading(MeSH)term“cost–benefit analysis”w... Objective:The aim of this study is to discover research status and hotspots of economic evaluation(EE)in nursing area using co-word cluster analysis.Methods:Medical Subject Heading(MeSH)term“cost–benefit analysis”was searched in PubMed and nursing journals were limited by the function of filter.The information of author,country,year,journal,and keywords of collected paper was extracted and exported to Bicomb 2.0 system,where high-frequency terms and other data could be further mined.SPSS 19.0 was used for cluster analysis to generate dendrogram.Results:In all,3,020 articles were found and 10,573 MeSH terms were detected;among them,1,909 were MeSH major topics and generated 42 high-frequency terms.The consequence of dendrogram showed seven clusters,representing seven research hotspots:skin administration,infection prevention,education program,nurse education and management,EE research,neoplasm patient,and extension of nurse function.Conclusions:Nursing EE research involved multiple aspects in nursing area,which is an important indicator for decision-making.Although the number of papers is increasing,the quality of study is not promising.Therefore,further study may be required to detect nurses’knowledge of economic analysis method and their attitude to apply it into nursing research.More nursing economics course could carry out in nursing school or hospitals. 展开更多
关键词 cost–benefit analysis co-word clustering analysis ECONOMIC evaluation NURSING NURSING education
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部