期刊文献+
共找到1,100,661篇文章
< 1 2 250 >
每页显示 20 50 100
Distribution of Traditional Chinese Medicine Syndromes and Syndrome Elements of Chronic Heart Failure Based on Network Analysis and Hierarchical Cluster Analysis
1
作者 ZHOU Yi HUANG Pinxian +1 位作者 LI Xiaoqian HE Jiancheng 《Chinese Medicine and Culture》 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
暂未订购
Profiling Brazil's research elite:Insights from a cluster analysis of a large database
2
作者 Cristian Rogério Foguesatto Denis Borenstein +1 位作者 Marcelo Perlin Takeyoshi Imasato 《Journal of Data and Information Science》 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
在线阅读 下载PDF
Collaborative State Estimation for Coupled Transmission and Distribution Systems Based on Clustering Analysis and Equivalent Measurement Modeling
3
作者 Hao Jiao Xinyu Liu +4 位作者 Chen Wu Chunlei Xu Zhijun Zhou Ye Chen Guoqiang Sun 《Energy Engineering》 2025年第7期2977-2992,共16页
With the continuous expansion of the power system scale and the increasing complexity of operational mode,the interaction between transmission and distribution systems is becoming more and more significant,placing hig... With the continuous expansion of the power system scale and the increasing complexity of operational mode,the interaction between transmission and distribution systems is becoming more and more significant,placing higher requirements on the accuracy and efficiency of the power system state estimation to address the challenge of balancing computational efficiency and estimation accuracy in traditional coupled transmission and distribution state estimation methods,this paper proposes a collaborative state estimation method based on distribution systems state clustering and load model parameter identification.To resolve the scalability issue of coupled transmission and distribution power systems,clustering is first carried out based on the distribution system states.As the data and models of the transmission system and distribution systems are not shared.For the transmission system,equating the power transmitted from the transmission system to the distribution system is the same as equating the distribution system.Further,the power transmitted from the transmission system to different types of distribution systems is equivalent to different polynomial equivalent load models.Then,a parameter identification method is proposed to obtain the parameters of the equivalent load model.Finally,a transmission and distribution collaborative state estimation model is constructed based on the equivalent load model.The results of the numerical analysis show that compared with the traditional master-slave splitting method,the proposed method significantly enhances computational efficiency while maintaining high estimation accuracy. 展开更多
关键词 Transmission and distribution collaboration cluster analysis parameter identification equivalent load state estimation
在线阅读 下载PDF
Enhanced BDS four-frequency cycle slip detection and repair using fuzzy clustering analysis
4
作者 Jinfeng Yuan Xiaoning Su Yuzhao Li 《Geodesy and Geodynamics》 2025年第4期439-453,共15页
Cycle slip detection and repair is one of the key technologies for GNSS high-precision positioning.We introduce an enhanced methodology for detecting and repairing BDS four-frequency cycle slips,utilizing fuzzy cluste... Cycle slip detection and repair is one of the key technologies for GNSS high-precision positioning.We introduce an enhanced methodology for detecting and repairing BDS four-frequency cycle slips,utilizing fuzzy clustering analysis.Firstly,based on fuzzy clustering analysis,the optimal combinations for the BDS four-frequency,including extra-wide lane(EWL),wide lane(WL),and narrow lane(NL),were selected.Secondly,the feasibility of this method was verified using actual static and dynamic observation data,and different types of cycle slips were simulated for further validation.Meanwhile,the proposed method was compared with the classical Turbo-Edit method through experiments.Finally,cycle slips were repaired using the least squares method.According to the experimental results,the optimal geometry-free phase combinations(-2,2,1,-1),(1,-1,1,-1),(3,2,-2,-3),and the pseudo-range phase combination(-1,1,1,-1),selected based on fuzzy clustering analysis,were used for cycle slip detection.The proposed method accurately detected small,large,and specific cycle slips simulated in the actual data.Compared with the Turbo-Edit method,the proposed methodwas able to detect specific cycle slips that Turbo-Edit could not.It is worth noting that during the repair process,the coefficients of the combined observation values are integers,preserving the integer cycle characteristic of the observation values,which allows cycle slips to be fixed directly,eliminating the need for complex searching procedures.Consequently,by enhancing the precision and reliability of the detection of BDS four-frequency cycle slips,our proposed method provides the support for the high-precision localization of BDS multi-frequency observations. 展开更多
关键词 BDS four-frequency Cycle slip detection and repair Fuzzy clustering analysis Geometry-free phase combinations Pseudo-range phase combination
原文传递
Exploring core symptoms and symptom clusters among patients with neuromyelitis optica spectrum disorder: A network analysis
5
作者 Hao Liang Jiehan Chen +4 位作者 Lixin Wang Zhuyun Liu Haoyou Xu Min Zhao Xiaopei Zhang 《International Journal of Nursing Sciences》 2025年第2期152-160,共9页
Objectives To identify core symptoms and symptom clusters in patients with neuromyelitis optica spectrum disorder(NMOSD)by network analysis.Methods From October 10 to 30,2023,140 patients with NMOSD were selected to p... Objectives To identify core symptoms and symptom clusters in patients with neuromyelitis optica spectrum disorder(NMOSD)by network analysis.Methods From October 10 to 30,2023,140 patients with NMOSD were selected to participate in this online questionnaire survey.The survey tools included a general information questionnaire and a self-made NMOSD symptoms scale,which included the prevalence,severity,and distress of 29 symptoms.Cluster analysis was used to identify symptom clusters,and network analysis was used to analyze the symptom network and node characteristics and central indicators including strength centrality(r_(s)),closeness centrality(r_(c))and betweeness centrality(r_(b))were used to identify core symptoms and symptom clusters.Results The most common symptom was pain(65.7%),followed by paraesthesia(65.0%),fatigue(65.0%),easy awakening(63.6%).Regarding the burden level of symptoms,pain was the most burdensome symptom,followed by paraesthesia,easy awakening,fatigue,and difficulty falling asleep.Six clusters were identified:somatosensory,motor,visual,and memory symptom clusters,bladder and rectum symptom clusters,sleep symptoms clusters,and neuropsychological symptom clusters.Fatigue(r_(s)=12.39,r_(b)=68.00,r_(c)=0.02)was the most central and prominent bridge symptom,and motor symptom cluster(r_(s)=2.68,r_(c)=0.10)was the most central symptom cluster among the six clusters.Conclusions Our study demonstrated the necessity of symptom management targeting fatigue,pain,and motor symptom cluster in patients with NMOSD. 展开更多
关键词 Neuromyelitis optica spectrum disorder Network analysis SYMPTOM Symptom clusters NURSING
暂未订购
Correlation Analysis Between Symptom Clusters and Quality of Life in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease
6
作者 Wenjie Wang Na Wang +1 位作者 Yujiao Wang Dan Liu 《Journal of Clinical and Nursing Research》 2025年第8期43-52,共10页
Objective:This study aims to investigate the patterns of symptom occurrence in patients experiencing acute exacerbations of chronic obstructive pulmonary disease(AECOPD).It will explore the composition of symptom clus... Objective:This study aims to investigate the patterns of symptom occurrence in patients experiencing acute exacerbations of chronic obstructive pulmonary disease(AECOPD).It will explore the composition of symptom clusters and analyze the correlation between these clusters and health-related quality of life(HRQoL).Methods:A total of 207 patients with AE-COPD were surveyed from a tertiary grade A hospital.Data collection was conducted using three validated instruments:the Basic Information Questionnaire(BIQ),Disease Symptom Survey Questionnaire(MSAS),and Quality of Life Questionnaire(CAT).Statistical software SPSS 22.0 was used to analyze the correlation between symptom clusters and quality of life.Results:Exploratory factor analysis showed that five major symptom clusters existed in the patients,including the psycho-emotional symptom cluster,the sleep-related symptom cluster,the other side effects symptom cluster,the energy deficiency symptom cluster and the cough-loss of appetite symptom cluster,and the severity of the symptom clusters showed a significant negative correlation with the quality of life of the patients(P<0.05).Conclusion:Strengthening the comprehensive management of symptom clusters in patients with AE-COPD can help to effectively reduce the symptom burden of patients,and then significantly improve their quality of life. 展开更多
关键词 COPD Acute exacerbation Symptom cluster Quality of life
暂未订购
Software Defect Prediction Based on Semantic Views of Metrics:Clustering Analysis and Model Performance Analysis
7
作者 Baishun Zhou Haijiao Zhao +4 位作者 Yuxin Wen Gangyi Ding Ying Xing Xinyang Lin Lei Xiao 《Computers, Materials & Continua》 2025年第9期5201-5221,共21页
In recent years,with the rapid development of software systems,the continuous expansion of software scale and the increasing complexity of systems have led to the emergence of a growing number of software metrics.Defe... In recent years,with the rapid development of software systems,the continuous expansion of software scale and the increasing complexity of systems have led to the emergence of a growing number of software metrics.Defect prediction methods based on software metric elements highly rely on software metric data.However,redundant software metric data is not conducive to efficient defect prediction,posing severe challenges to current software defect prediction tasks.To address these issues,this paper focuses on the rational clustering of software metric data.Firstly,multiple software projects are evaluated to determine the preset number of clusters for software metrics,and various clustering methods are employed to cluster the metric elements.Subsequently,a co-occurrence matrix is designed to comprehensively quantify the number of times that metrics appear in the same category.Based on the comprehensive results,the software metric data are divided into two semantic views containing different metrics,thereby analyzing the semantic information behind the software metrics.On this basis,this paper also conducts an in-depth analysis of the impact of different semantic view of metrics on defect prediction results,as well as the performance of various classification models under these semantic views.Experiments show that the joint use of the two semantic views can significantly improve the performance of models in software defect prediction,providing a new understanding and approach at the semantic view level for defect prediction research based on software metrics. 展开更多
关键词 Software defect prediction software engineering semantic views clusterING INTERPRETABILITY
在线阅读 下载PDF
Evaluating the scope of human leukocyte antigen polymorphisms influencing hepatitis B virus-related liver cancer and cirrhosis through multi-clustering analysis
8
作者 Shi Li Yue Xi +3 位作者 Xue-Ying Dong Wen-Bin Yuan Jing-Feng Tang Ce-Fan Zhou 《World Journal of Gastroenterology》 2025年第7期156-159,共4页
Hepatitis B virus remains a major cause of cirrhosis and hepatocellular carcinoma,with genetic polymorphisms and mutations influencing immune responses and disease progression.Nguyen et al present novel findings on sp... Hepatitis B virus remains a major cause of cirrhosis and hepatocellular carcinoma,with genetic polymorphisms and mutations influencing immune responses and disease progression.Nguyen et al present novel findings on specific human leukocyte antigen(HLA)alleles,including rs2856718 of HLA-DQ and rs3077 and rs9277535 of HLA-DP,which may predispose individuals to cirrhosis and liver cancer,based on multi-clustering analysis.Here,we discuss the feasibility of this approach and identify key areas for further investigation,aiming to offer insights for advancing clinical practice and research in liver disease and related cancers. 展开更多
关键词 Hepatitis B virus Gene polymorphisms Multi-clustering analysis Genetic markers Personalized medicine Clinical implications
暂未订购
Enhancing Heart Sound Classification with Iterative Clustering and Silhouette Analysis:An Effective Preprocessing Selective Method to Diagnose Rare and Difficult Cardiovascular Cases
9
作者 Sami Alrabie Ahmed Barnawi 《Computer Modeling in Engineering & Sciences》 2025年第8期2481-2519,共39页
In the effort to enhance cardiovascular diagnostics,deep learning-based heart sound classification presents a promising solution.This research introduces a novel preprocessing method:iterative k-means clustering combi... In the effort to enhance cardiovascular diagnostics,deep learning-based heart sound classification presents a promising solution.This research introduces a novel preprocessing method:iterative k-means clustering combined with silhouette score analysis,aimed at downsampling.This approach ensures optimal cluster formation and improves data quality for deep learning models.The process involves applying k-means clustering to the dataset,calculating the average silhouette score for each cluster,and selecting the clusterwith the highest score.We evaluated this method using 10-fold cross-validation across various transfer learningmodels fromdifferent families and architectures.The evaluation was conducted on four datasets:a binary dataset,an augmented binary dataset,amulticlass dataset,and an augmentedmulticlass dataset.All datasets were derived from the Heart Wave heart sounds dataset,a novelmulticlass dataset introduced by our research group.To increase dataset sizes and improve model training,data augmentation was performed using heartbeat cycle segmentation.Our findings highlight the significant impact of the proposed preprocessing approach on the HeartWave datasets.Across all datasets,model performance improved notably with the application of our method.In augmented multiclass classification,the MobileNetV2 model showed an average weighted F1-score improvement of 27.10%.In binary classification,ResNet50 demonstrated an average accuracy improvement of 8.70%,reaching 92.40%compared to its baseline performance.These results underscore the effectiveness of clustering with silhouette score analysis as a preprocessing step,significantly enhancing model accuracy and robustness.They also emphasize the critical role of preprocessing in addressing class imbalance and advancing precision medicine in cardiovascular diagnostics. 展开更多
关键词 Heart sound MURMURS cardiovascular diseases(CVDs) transfer learning convolutional neural network(CNN) deep learning K-means silhouette analysis
在线阅读 下载PDF
Evaluation of the protective effects of Crocus sativus L.against cypermethrin induced reproductive toxicity in male rats through the Nrf2 pathway and in silico ADMET analysis
10
作者 Fareena Tariq Farah Ijaz +9 位作者 Yasameen Hameed Jasim Farah Naz Channa Sohail Ahmed Ahmed Shandookh Hameed Sobia Alyas Ahmed Raheem Rayshan Tahira Bibi Nazima Yousaf Khan Sadia Bibi Jameel Ahmed Buzdar 《Traditional Medicine Research》 2026年第3期12-25,共14页
Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to i... Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to its therapeutic properties,but its exact role and molecular mechanisms in treatment of reproductive dysfunction remain unclear.Methods:During this study,36 rats were randomly divided into six groups(n=6):control,CYP-induced(60 mg/kg),standard(leuprolide 3 mg/kg)and three treatment groups receiving aqueous,ethanolic,and oil extracts(50 mg/kg or 20 mL/kg)for post-toxicity induction.Results:The finding represented that exposure of CYP significantly increased oxidative stress,disrupted testicular architecture,and markedly reduced testosterone levels(P<0.05).Importantly,Crocus sativus L.treatment alleviated these changes by increasing the expression of Nrf2(nuclear factor erythroid 2-related factor 2),restoring the activity of antioxidant enzymes,and enhancing testicular histomorphology.Surprisingly,molecular docking established a high binding affinity of Crocus sativus L.phytoconstituents such as gallic acid,cinnamic acid and quercetin to the Nrf2-Keap1 complex.It is worth noting that,Crocus sativus L.exhibited a high level of protection against reproductive toxicity caused by CYP in male rats,which was mediated by the activation of Nrf2 pathway,reduction of oxidative damage,and favorable ADMET characteristics.Conclusion:Notably,this research provides a more valid,safe,and effective method of developing new drugs for reproductive disorders,however,further investigation is needed to support the research findings and implement it in clinical practice. 展开更多
关键词 Crocus sativus L. CYPERMETHRIN male reproductive toxicity Nrf2 pathway in silico ADMET analysis
暂未订购
Changes in border-associated macrophages after stroke: Single-cell sequencing analysis
11
作者 Ning Yu Yang Zhao +3 位作者 Peng Wang Fuqiang Zhang Cuili Wen Shilei Wang 《Neural Regeneration Research》 2026年第1期346-356,共11页
Border-associated macrophages are located at the interface between the brain and the periphery, including the perivascular spaces, choroid plexus, and meninges. Until recently, the functions of border-associated macro... Border-associated macrophages are located at the interface between the brain and the periphery, including the perivascular spaces, choroid plexus, and meninges. Until recently, the functions of border-associated macrophages have been poorly understood and largely overlooked. However, a recent study reported that border-associated macrophages participate in stroke-induced inflammation, although many details and the underlying mechanisms remain unclear. In this study, we performed a comprehensive single-cell analysis of mouse border-associated macrophages using sequencing data obtained from the Gene Expression Omnibus(GEO) database(GSE174574 and GSE225948). Differentially expressed genes were identified, and enrichment analysis was performed to identify the transcription profile of border-associated macrophages. CellChat analysis was conducted to determine the cell communication network of border-associated macrophages. Transcription factors were predicted using the ‘pySCENIC' tool. We found that, in response to hypoxia, borderassociated macrophages underwent dynamic transcriptional changes and participated in the regulation of inflammatory-related pathways. Notably, the tumor necrosis factor pathway was activated by border-associated macrophages following ischemic stroke. The pySCENIC analysis indicated that the activity of signal transducer and activator of transcription 3(Stat3) was obviously upregulated in stroke, suggesting that Stat3 inhibition may be a promising strategy for treating border-associated macrophages-induced neuroinflammation. Finally, we constructed an animal model to investigate the effects of border-associated macrophages depletion following a stroke. Treatment with liposomes containing clodronate significantly reduced infarct volume in the animals and improved neurological scores compared with untreated animals. Taken together, our results demonstrate comprehensive changes in border-associated macrophages following a stroke, providing a theoretical basis for targeting border-associated macrophages-induced neuroinflammation in stroke treatment. 展开更多
关键词 border-associated macrophages CLODRONATE hypoxia ISCHEMIA-REPERFUSION ischemic stroke liposomes neuroinflammation single-cell sequencing analysis STAT3 tumor necrosis factor
暂未订购
Variation and Cluster Analysis on Leaf Characters from Different Provenance Sources of Polygonum multiflorum Thunb 被引量:2
12
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
在线阅读 下载PDF
Application of cluster analysis and stepwise regression in predicting the traffic volume of lanes 被引量:5
13
作者 张赫 王炜 顾怀中 《Journal of Southeast University(English Edition)》 EI CAS 2005年第3期359-362,共4页
Because of the difficulty to obtain the traffic flow information of lanes at non-detector intersections in most metropolises of the world,based on the relationships between the lanes of signal-controlled intersections... Because of the difficulty to obtain the traffic flow information of lanes at non-detector intersections in most metropolises of the world,based on the relationships between the lanes of signal-controlled intersections,cluster analysis and stepwise regression are integrated to predict the traffic volume of lanes at non-detector isolated controlled intersections.First cluster analysis is used to cluster the lanes of non-detector isolated signal-controlled intersections and the lanes of all signal-controlled intersections with detectors.Then, by the results of cluster analysis,the traffic volume samples are selected randomly and stepwise regression is used to predict the traffic volume of lanes at non-detector isolated signal-controlled intersections.The method is tested by the traffic volume data of lanes of the road network of Nanjing city.The problem of predicting the traffic volume of lanes at non-detector isolated signal-controlled intersections was resolved and can be widely used in urban traffic flow guidance and urban traffic control in cities without enough intersections equipped with detectors. 展开更多
关键词 intelligent transportation systems (ITS) cluster analysis stepwise regression
在线阅读 下载PDF
Characterizing heterogeneity in vehicular traffic speed using two-step cluster analysis 被引量:3
14
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
在线阅读 下载PDF
Group decision-making method based on entropy and experts cluster analysis 被引量:12
15
作者 Xuan Zhou Fengming Zhang 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 preferen... 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.
在线阅读 下载PDF
Cluster Analysis of Morphologic Characteristic of Eight Geographical Populations of Rana Dybowskii 被引量:1
16
作者 应璐 徐艳春 +2 位作者 黄孝明 田秀华 汪青雄 《Agricultural Science & Technology》 CAS 2008年第1期104-106,110,共4页
[ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices (body length, body weight, forelimb length, hindlimb length) of eight geogra... [ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices (body length, body weight, forelimb length, hindlimb length) of eight geographical populations of R.dybowskii which naturally distribute in Changhai Mountain and Xiaoxing'an Mountain were measured. Measure results were variance analyzed and cluster analyzed. [Result] Variance analysis showed: the genetic branching among the Dongfanghong male population( belongs to Wandashan) and Xiaoxing'an Mountain male population and Changbai Mountain male population were significantly different (P〈0.05) ; the genetic branching between the Hebei female population (belongs to Xiaoxing'an Mountain) and Changbai Mountain female population was significantly different (P〈0.05 ). Cluster analysis showed : male R.dybowskii can be divided into three groups : the first group included Quanyang, Tianbei, Chaoyang and Ddkouqin, the second group included Tieli and Anshan, the third group included Dongfanghong; and the female R. dybowskii can be divided into three groups : the first group included Quanyang and Chaoyang, the second group included Tianbei and Dakouqin, the third group included Hebei. [Condusion] The paper deduced that the Sanjiang Plain was the geographical origin center ofR. dybowskii which radiated to Changbai Mountain and Xiaoxing'an Mountain along the adverse current of Songhua River basin, therefore, the current distribution pattern of R. dybowskii was formed. 展开更多
关键词 Rana dybowskii Geographical population Morphologic characteristic Distribution pattern Geographical origin cluster analysis
在线阅读 下载PDF
Genetic Diversity and Clustering Analysis of 48Cultivars of Olea euyopaea L. 被引量:1
17
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
在线阅读 下载PDF
Clustering analysis algorithm for security supervising data based on semantic description in coal mines 被引量:1
18
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
在线阅读 下载PDF
Cluster Analysis of Chinese Pumpkin Inbred Lines 被引量:7
19
作者 杜晓华 李小梅 李新峥 《Agricultural Science & Technology》 CAS 2008年第4期104-107,共4页
A cluster analysis was carried out based on Euclidean genetic distances through UPGMA method in Chinese pumpkin inbred lines.7 important agronomic traits of 46 Chinese pumpkin inbred lines were investigated.The result... A cluster analysis was carried out based on Euclidean genetic distances through UPGMA method in Chinese pumpkin inbred lines.7 important agronomic traits of 46 Chinese pumpkin inbred lines were investigated.The result indicated that 46 pumpkin inbred lines were clustered into 4 groups and the inter-groups distances was larger than that in intra-group.The genetic distances of parents were related to F1 performance and the results of cluster would increase effectiveness in the Chinese pumpkin crossing breeding. 展开更多
关键词 CHINESE PUMPKIN INBRED LINES cluster
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部