期刊文献+
共找到969篇文章
< 1 2 49 >
每页显示 20 50 100
Keyword Co-occurrence Analysis of Research on Innovation Ecosystem Studies
1
作者 Pengbin Gao Jianxin Zhao Xue Li 《经济管理学刊(中英文版)》 2019年第2期173-179,共7页
The aim of the paper is to identify and explore leading thematic areas within the research field related to innovation ecosystem.Based on data from the Web of Science database,the keywords frequency and its co-occurre... The aim of the paper is to identify and explore leading thematic areas within the research field related to innovation ecosystem.Based on data from the Web of Science database,the keywords frequency and its co-occurrence frequency pair were analyzed,and the theory of mapping knowledge domains was used to visualize the keywords co-occurrence network in innovation ecosystem to make further research of the heated issues.The findings indicate that the research scope involved in innovation ecosystem research is broad,and research content focus on micro and macro levels.According to the results of keywords co-occurrence analysis of different stages,innovation,network,knowledge,strategy,open innovation,value creation are the most important issues to innovation ecosystem research,given their position and role in the research network.The paper generates the added value mainly from the point of view of theory development. 展开更多
关键词 Innovation Ecosystem Research Knowledge Mapping Visualization analysis keyword co-occurrence
下载PDF
Determining future high speed rail review topics through bibliometric analysis
2
作者 Heather Steele Marcelo Blumenfeld Paul Plummer 《High-Speed Railway》 2024年第1期17-29,共13页
As High Speed Rail(HSR)has proliferated globally,so has a related research field dedicated to exploring and addressing its unique issues.Yet,studies to understand and classify the HSR research domain are limited.This ... As High Speed Rail(HSR)has proliferated globally,so has a related research field dedicated to exploring and addressing its unique issues.Yet,studies to understand and classify the HSR research domain are limited.This paper addresses the gap,using bibliometric analysis to identify future research areas and 20 candidate topics for literature review based on keyword analysis through VOSviewer.Article and review papers related to HSR published in the last 20 years(2003-2022)were retrieved from Scopus,and then analyzed to determine the split in knowledge between languages,the collaboration between countries and institutions,highly productive and cited journals,and research topics which have and have not been reviewed.Approximately 30%of the search results were published exclusively in Chinese,highlighting the importance of extending the evaluation to cover both languages.This is a novel aspect of the work,which has enabled the recognition of potential knowledge gaps.It is recommended that future reviews incorporate works in both languages,possibly through international collaboration.Institutions in China and other countries that are strong collaborators have been identified,as well as relevant,highly cited journals. 展开更多
关键词 High speed rail Literature review Bibliometric analysis Vosviewer keyword co-occurrence
下载PDF
A knowledge discovery method based on analysis of multiple co-occurrence relationships in collections of journal papers 被引量:4
3
作者 Hongshen PANG 《Chinese Journal of Library and Information Science》 2012年第4期9-20,共12页
Purpose: This paper explores a method of knowledge discovery by visualizing and analyzing co-occurrence relations among three or more entities in collections of journal articles.Design/methodology/approach: A variety ... Purpose: This paper explores a method of knowledge discovery by visualizing and analyzing co-occurrence relations among three or more entities in collections of journal articles.Design/methodology/approach: A variety of methods such as the model construction,system analysis and experiments are used. The author has improved Morris' crossmapping technique and developed a technique for directly describing,visualizing and analyzing co-occurrence relations among three or more entities in collections of journal articles.Findings: The visualization tools and the knowledge discovery method can efficiently reveal the multiple co-occurrence relations among three entities in collections of journal papers. It can reveal more and in-depth information than analyzing co-occurrence relations between two entities. Therefore,this method can be used for mapping knowledge domain that is manifested in association with the entities from multi-dimensional perspectives and in an all-round way.Research limitations: The technique could only be used to analyze co-occurrence relations of less than three entities at present.Practical implications: This research has expanded the study scope of co-occurrence analysis.The research result has provided a theoretical support for co-occurrence analysis.Originality/value: There has not been a systematic study on co-occurrence relations among multiple entities in collections of journal articles. This research defines multiple co-occurrence and the research scope,develops the visualization analysis tool and designs the analysis model of the knowledge discovery method. 展开更多
关键词 Multiple co-occurrence Visualization analysis Knowledge discovery Research field analysis Embryonic stem cell
下载PDF
The reflection of hierarchical cluster analysis of co-occurrence matrices in SPSS 被引量:5
4
作者 Qiuju ZHOU Fuhai LENG Loet LEYDESDORFF 《Chinese Journal of Library and Information Science》 2015年第2期11-24,共14页
Purpose: To discuss the problems arising from hierarchical cluster analysis of co-occurrence matrices in SPSS, and the corresponding solutions. Design/methodology/approach: We design different methods of using the S... Purpose: To discuss the problems arising from hierarchical cluster analysis of co-occurrence matrices in SPSS, and the corresponding solutions. Design/methodology/approach: We design different methods of using the SPSS hierarchical clustering module for co-occurrence matrices in order to compare these methods. We offer the correct syntax to deactivate the similarity algorithm for clustering analysis within the hierarchical clustering module of SPSS. Findings: When one inputs co-occurrence matrices into the data editor of the SPSS hierarchical clustering module without deactivating the embedded similarity algorithm, the program calculates similarity twice, and thus distorts and overestimates the degree of similarity. Practical implications: We offer the correct syntax to block the similarity algorithm for clustering analysis in the SPSS hierarchical clustering module in the case of co-occurrence matrices. This syntax enables researchers to avoid obtaining incorrect results. Originality/value: This paper presents a method of editing syntax to prevent the default use of a similarity algorithm for SPSS's hierarchical clustering module. This will help researchers, especially those from China, to properly implement the co-occurrence matrix when using SPSS for hierarchical cluster analysis, in order to provide more scientific and rational results. 展开更多
关键词 co-occurrence matrices Hierarchical cluster analysis SPSS Similarity algorithm The syntax editor
下载PDF
Spatio-Temporal Variations in Co-Occurrence Patterns of Fish Communities in Haizhou Bay, China: Null Model Analysis
5
作者 WANG Jiao ZHANG Chongliang +3 位作者 XUE Ying CHEN Yong REN Yiping XU Binduo 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第6期1497-1506,共10页
Co-occurrence pattern of fish species plays an important role in understanding the spatio-temporal structure and the stability of fish community.Species coexistence may vary with time and space.The co-occurrence patte... Co-occurrence pattern of fish species plays an important role in understanding the spatio-temporal structure and the stability of fish community.Species coexistence may vary with time and space.The co-occurrence patterns of fish species were examined using the C-score under fixed-fixed null model for fish communities in spring and autumn over different years in the Haizhou Bay,China.The results showed that fish assemblages in the whole bay had non-random patterns in spring and autumn over different years.However,the fish co-occurrence patterns were different for the northern and southern fish assemblages in spring and autumn.The northern fish assemblage showed structured pattern,whereas the southern assemblage were randomly assembled in spring.The co-occurrence patterns of fish communities were relatively stable over different years,and the number of significant species pairs in northern assemblage was more than that in the southern assemblage.Environmental heterogeneity played an important role in determining the distributions of fish species that formed significant species pairs,which might affect the co-occurrence patterns of northern and southern assemblages further in the Haizhou Bay. 展开更多
关键词 FISH COMMUNITY Haizhou BAY NULL model analysis SPECIES co-occurrence pattern
下载PDF
Visual Exploration Research in the Field of Library and Information Based on Co-occurrence Analysis
6
作者 Hao Wang 《Proceedings of Business and Economic Studies》 2019年第4期13-17,共5页
Towards current modern society,our country’s library and information science is not only rapid development,but it also has won the favor of many researchers in more than a decade of development.Due to new technology ... Towards current modern society,our country’s library and information science is not only rapid development,but it also has won the favor of many researchers in more than a decade of development.Due to new technology elements and methods are widely used in the discipline of library and information science,cause society our country’s library and information science has entered a new stage with the development of information industry.This paper is based on the research theory of co-occurrence analysis,clustering co-occurrence analysis of references,social network co-occurrence analysis from researchers and research institutions of the field of library and information science,to have more precise and in depth research on the research focus of the library and information science,the authors themselves and the research institutions circumstances over the past few years.At the same time,the theory is used to analyze the effects and analysis of accurate data,to ensure that researchers can analyze the theory of library and information science for a long time. 展开更多
关键词 co-occurrence analysis FIELD of LIBRARY and information VISUALIZATION EXPLORATION RESEARCH
下载PDF
Research on Subject Areas of Innovation Ecosystem: A Discipline Co-occurrence Analysis
7
作者 Pengbin Gao Jianxin Zhao Xue Li 《经济管理学刊(中英文版)》 2019年第2期166-172,共7页
Based on data from the Web of Science database,co-occurrence analysis and network visualization technique were conducted to explore the structure and patterns of interdisciplinary collaborations in innovation ecosyste... Based on data from the Web of Science database,co-occurrence analysis and network visualization technique were conducted to explore the structure and patterns of interdisciplinary collaborations in innovation ecosystem research.This study presented the descriptive statistics of disciplines involved in relative research and interdisciplinary network over time.The results suggested that the scope of disciplines involved in innovation ecosystem research is broad and the distribution is unbalanced.Management and business are the core subject area while Regional&Urban Planning,Environmental Studies,and Environmental Sciences are playing key role in research and practices. 展开更多
关键词 Innovation Ecosystem Research Interdisciplinary Collaboration Discipline co-occurrence analysis
下载PDF
A Metric Approach to Hot Topics in Biomedicine via Keyword Co-occurrence 被引量:1
8
作者 Jane H.Qin Jean J.Wang Fred Y.Ye 《Journal of Data and Information Science》 CSCD 2019年第4期13-25,共13页
Purpose:To reveal the research hotpots and relationship among three research hot topics in b iomedicine,namely CRISPR,iPS(induced Pluripotent Stem)cell and Synthetic biology.Design/methodology/approach:We set up their... Purpose:To reveal the research hotpots and relationship among three research hot topics in b iomedicine,namely CRISPR,iPS(induced Pluripotent Stem)cell and Synthetic biology.Design/methodology/approach:We set up their keyword co-occurrence networks with using three indicators and information visualization for metric analysis.Findings:The results reveal the main research hotspots in the three topics are different,but the overlapping keywords in the three topics indicate that they are mutually integrated and interacted each other.Research limitations:All analyses use keywords,without any other forms.Practical implications:We try to find the information distribution and structure of these three hot topics for revealing their research status and interactions,and for promoting biomedical developments.Originality/value:We chose the core keywords in three research hot topics in biomedicine by using h-index. 展开更多
关键词 keyword co-occurrence Network analysis Information visualization BIOMEDICINE Hot topics CRISPR-Cas iPS cell Synthetic biology
下载PDF
A Corpus-based Analysis of Keywords in Chinese Government Work Reports and State of the Union from the Perspective of Political Linguistics
9
作者 LIU Hui LIU Ying-liang 《Journal of Literature and Art Studies》 2022年第5期462-468,共7页
This study compared and analyzed the features of keywords and their collocations in corpora:Chinese Government Work Reports and State of the Union(USA).A further comparison and analysis of the collocations of“develop... This study compared and analyzed the features of keywords and their collocations in corpora:Chinese Government Work Reports and State of the Union(USA).A further comparison and analysis of the collocations of“develop”and“improve”was then conducted from the perspective of political linguistics.Results suggested that China and the United States have their own emphasis of government work.It was also indicated that“we”and“will”are both high-frequency keywords and combinations of“develop”and“improve”,which shows that both countries give the highest priority to narrowing the distance between the government and the public. 展开更多
关键词 keywordS COLLOCATIONS political linguistics corpus-based analysis
下载PDF
The Research on E-mail Users' Behavior of Participating in Subjects Based on Social Network Analysis 被引量:3
10
作者 ZHANG Lejun ZHOU Tongxin +2 位作者 Qi Zhixin GUO Lin XU Li 《China Communications》 SCIE CSCD 2016年第4期70-80,共11页
The e-mail network is a type of social network. This study analyzes user behavior in e-mail subject participation in organizations by using social network analysis. First, the Enron dataset and the position-related in... The e-mail network is a type of social network. This study analyzes user behavior in e-mail subject participation in organizations by using social network analysis. First, the Enron dataset and the position-related information of an employee are introduced, and methods for deletion of false data are presented. Next, the three-layer model(User, Subject, Keyword) is proposed for analysis of user behavior. Then, the proposed keyword selection algorithm based on a greedy approach, and the influence and propagation of an e-mail subject are defined. Finally, the e-mail user behavior is analyzed for the Enron organization. This study has considerable significance in subject recommendation and character recognition. 展开更多
关键词 E-MAIL NETWORK social NETWORK analysis user BEHAVIOR analysis keyword selection
下载PDF
A study on clinical nursing research trends and hotspots based on bibliometric analysis 被引量:1
11
作者 Shi-Fan Han Rui-Fang Zhu Ting-Ting Qin 《Chinese Nursing Research》 CAS 2017年第4期162-169,共8页
Objective: This study was conducted to understand the trends and research hotspots of clinical nursing in China and abroad, thereby to provide guidance for nursing practice and studies.Methods: We retrieved clinical n... Objective: This study was conducted to understand the trends and research hotspots of clinical nursing in China and abroad, thereby to provide guidance for nursing practice and studies.Methods: We retrieved clinical nursing literature(excluding literature related to psychological nursing and traditional Chinese medicine nursing) cited in Wanfang Data(www.wanfangdata.com.cn) and PubMed between 2007 and 2015 and subsequently performed bibliometric analyses on article volume,journal, clustering of high-frequency keywords, and co-occurrence of keywords.Results: A total of 10374 publications, excluding those related to psychological nursing, were retrieved via a PubMed search. The literature displayed a rising trend in terms of annual publication volume. The journal distribution of clinical nursing publications overall was consistent with Bradford's Law. The main contents of clinical nursing literature between 2007 and 2009 included:(1) studies on effects of the midwife and midwifery methods for natural childbirth;(2) studies on emergency nursing care;(3)studies on dementia care;(4) studies on bandage dressing in trauma nursing; and(5) studies on quality of life in cancer patients nursing. The main contents of clinical nursing literature between 2010 and 2012 included:(1) studies on obstetric nurse-patient relationships;(2) studies on patients' medical team in stroke nursing;(3) studies on cancer nursing methods;(4) studies on nursing patients with trauma related to urinary incontinence; and(5) studies on the quality of life of caregivers of dementia patients.The main contents of clinical nursing literature between 2013 and 2015 included(1) studies on skin care and bandaging in trauma nursing;(2) studies on evidence-based nursing in AIDS care;(3) studies on nurses' role in obstetric nurse-patient relationships; studies on cancer nursing methods;(4) studies on nursing for Alzheimer's disease and dementia; and(5) studies on caregivers and nursing of stroke patients. A Wanfang Data search retrieved a total of 85570 publications, whose volume also exhibited an annual rising trend, in particular with regard to those in core journals. However, percentage of total publication volume, mean cited frequency per article, and total ranking of clinical nursing publications overall displayed a decreasing trend. The main contents of clinical nursing literature between 2007 and 2009 included:(1) diabetes nursing;(2) nursing for cancer;(3) nursing for senility-related diseases;(4)nursing in the event of complications;(5) nursing for hypertension;(6) studies on quality of life after nursing interventions;(7) chemotherapy nursing;(8) studies on compliance after nursing interventions;(9) constipation nursing; and(10) nursing for stroke patients. The main contents of clinical nursing literature between 2010 and 2012 included:(1) diabetes nursing;(2) nursing for cancer;(3) nursing for senility-related diseases;(4) studies on quality of life after nursing interventions;(5) nursing in the event of complications;(6) nursing for hypertension;(7) prevention nursing;(8) perioperative nursing;(9)pain nursing; and(10) studies on compliance after nursing interventions. The main contents of clinical nursing literature between 2013 and 2015 included:(1) diabetes nursing;(2) nursing in the event of complications;(3) cancer nursing;(4) studies on quality of life after nursing interventions;(5) nursing for stroke patients;(6) nursing for the elderly;(7) studies on compliance after nursing interventions;(8)nursing for hypertension;(9) constipation nursing; and(10) prevention nursing.Conclusions: Clinical nursing research in China is in a rapid development stage as defined by Price's law whereby there is a rapid growth in publication volume. By comparison, clinical nursing research in developed countries is in the stable development stage or maturation phase, which is characterized by a flat curve of publication volume and stable development rate. There is a gap of 25-30 years between China and these countries in terms of the growth phases of clinical nursing literature. 展开更多
关键词 Clinical NURSING keywordS Research HOTSPOTS BIBLIOMETRICS Cluster analysis co-occurrence analysis
下载PDF
Assembly and co-occurrence patterns of rare and abundant bacterial sub-communities in rice rhizosphere soil under short-term nitrogen deep placement 被引量:2
12
作者 LI Gui-long WU Meng +5 位作者 LI Peng-fa WEI Shi-ping LIU Jia JIANG Chun-yu LIU Ming LI Zhong-pei 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2021年第12期3299-3311,共13页
Nitrogen(N)deep placement has been found to reduce N leaching and increase N use efficiency in paddy fields.However,relatively little is known how bacterial consortia,especially abundant and rare taxa,respond to N dee... Nitrogen(N)deep placement has been found to reduce N leaching and increase N use efficiency in paddy fields.However,relatively little is known how bacterial consortia,especially abundant and rare taxa,respond to N deep placement,which is critical for understanding the biodiversity and function of agricultural ecosystem.In this study,lllumina sequencing and ecological models were conducted to examine the diversity patterns and underlying assembly mechanisms of abundant and rare taxa in rice rhizosphere soil under different N fertilization regimes at four rice growth stages in paddy fields.The results showed that abundant and rare bacteria had distinct distribution patterns in rhizosphere samples.Abundant bacteria showed ubiquitous distribution;while rare taxa exhibited uneven distribution across all samples.Stochastic processes dominated community assembly of both abundant and rare bacteria,with dispersal limitation playing a more vital role in abundant bacteria,and undominated processes playing a more important role in rare bacteria.The N deep placement was associated with a greater influence of dispersal limitation than the broadcast N fertilizer(BN)and no N fertilizer(NN)treatments in abundant and rare taxa of rhizosphere soil;while greater contributions from homogenizing dispersal were observed for BN and NN in rare taxa.Network analysis indicated that abundant taxa with closer relationships were usually more likely to occupy the central position of the network than rare taxa.Nevertheless,most of the keystone species were rare taxa and might have played essential roles in maintaining the network stability.Overall,these findings highlighted that the ecological mechanisms and co-occurrence patterns of abundant and rare bacteria in rhizosphere soil under N deep placement. 展开更多
关键词 rare bacteria community assembly network analysis co-occurrence patterns N deep placement
下载PDF
Aspect-Based Sentiment Analysis for Polarity Estimation of Customer Reviews on Twitter 被引量:1
13
作者 Ameen Banjar Zohair Ahmed +2 位作者 Ali Daud Rabeeh Ayaz Abbasi Hussain Dawood 《Computers, Materials & Continua》 SCIE EI 2021年第5期2203-2225,共23页
Most consumers read online reviews written by different users before making purchase decisions,where each opinion expresses some sentiment.Therefore,sentiment analysis is currently a hot topic of research.In particula... Most consumers read online reviews written by different users before making purchase decisions,where each opinion expresses some sentiment.Therefore,sentiment analysis is currently a hot topic of research.In particular,aspect-based sentiment analysis concerns the exploration of emotions,opinions and facts that are expressed by people,usually in the form of polarity.It is crucial to consider polarity calculations and not simply categorize reviews as positive,negative,or neutral.Currently,the available lexicon-based method accuracy is affected by limited coverage.Several of the available polarity estimation techniques are too general and may not reect the aspect/topic in question if reviews contain a wide range of information about different topics.This paper presents a model for the polarity estimation of customer reviews using aspect-based sentiment analysis(ABSA-PER).ABSA-PER has three major phases:data preprocessing,aspect co-occurrence calculation(CAC)and polarity estimation.A multi-domain sentiment dataset,Twitter dataset,and trust pilot forum dataset(developed by us by dened judgement rules)are used to verify ABSA-PER.Experimental outcomes show that ABSA-PER achieves better accuracy,i.e.,85.7%accuracy for aspect extraction and 86.5%accuracy in terms of polarity estimation,than that of the baseline methods. 展开更多
关键词 Natural language processing sentiment analysis aspect co-occurrence calculation sentiment polarity customer reviews twitte
下载PDF
Current Situation and Prospect of Sports Tourism Research Based on CiteSpace Bibliometric Analysis 被引量:1
14
作者 LIU Chao YUAN Mengxuan TIAN Fang 《Journal of Landscape Research》 2022年第3期54-60,共7页
Based on CNKI database,the paper takes journal literatures with the theme of “sports tourism” as the research objects to draw knowledge map through bibliometrics method and CiteSpace software.Moreover,the paper draw... Based on CNKI database,the paper takes journal literatures with the theme of “sports tourism” as the research objects to draw knowledge map through bibliometrics method and CiteSpace software.Moreover,the paper draws knowledge map and analyses for 1,208 periodical literatures with the theme of “sports tourism” in CNKI from 2002 to 2022.The results show that the sports tourism research from 2002 to 2022 can be divided into three stages:The first is the accelerated development stage,which focuses on the industrialization development of sports tourism;The second is the rapid prosperity stage,which focuses on how to promote economic development,and constantly deepen and enrich the connotation of sports tourism industry;The third is the rising stage of fluctuation,which begins to explore new development opportunities of sports tourism from multiple perspectives.Based on keywords co-occurrence analysis and cluster analysis,the research hotspots and changes of sports tourism in China are obtained.Five key research hotspots and three main directions are extracted to provide reference for the development of sports tourism research hotspots in the future. 展开更多
关键词 Sports tourism CITESPACE Research hotspot Knowledge graph Cluster analysis co-occurrence analysis
下载PDF
Evaluation of trend in semen analysis for 11 years in subjects attending a fertility clinic in India 被引量:10
15
作者 P.Marimuthu M.C.Kapilashrami +1 位作者 M.M.Misro G.Singh 《Asian Journal of Andrology》 SCIE CAS CSCD 2003年第3期221-225,共5页
Aim: The data on semen analysis of subjects attending the Fertility Clinic at NIHFW (National Institute of Health and Family Welfare) Munirka, New Delhi for the last 11 years were analyzed to verify the claims and spe... Aim: The data on semen analysis of subjects attending the Fertility Clinic at NIHFW (National Institute of Health and Family Welfare) Munirka, New Delhi for the last 11 years were analyzed to verify the claims and speculations on declining sperm counts in men. Methods: Approximately 10 % of the records every year starting from 1990 to 2000 (numbering 1176 in total) were randomly selected for analysis. Subjects with azoospermia or severe oligozoospermia were excluded from analysis. Results: The average age of the men attending the infertility clinic was 31.2 years. The average semen volume and sperm count were found to be (2.6 ±0.1) mL and (60.6 ± 0.9) × 106/mL, respectively. No significant decline in sperm counts was observed in any year during the entire study period. Only 1.8 % of the total number of sperm counts in the random sampling were less then 20 × 106/mL. On the basis of WHO criteria on motility, the total percentage of non-progressive and non-motile sperm in the ejaculate was higher (63 %) as compared to the combined categories of slow and rapid linear progressive. Conclusion: The present study has confirmed similar findings from other different countries that declining sperm counts in humans is not a global phenomenon. 展开更多
关键词 <keyword>semen analysis sperm motility declining sperm count male infertility
下载PDF
VECTOR ANALYSIS THEORY ON LANDSCAPE PATTERN (VATLP) IN SANJIANG PLAIN MARSH, CHINA 被引量:13
16
作者 ZHANGShu-Qing ZHANGJun-Yan LIFang 《湿地科学》 CSCD 2004年第3期161-170,共10页
Landscape indices are popular for the quantification of landscape pattern. But all landscape indices being used so far are scalar quantity, which measure patterns without considering sufficiently the pattern size and ... Landscape indices are popular for the quantification of landscape pattern. But all landscape indices being used so far are scalar quantity, which measure patterns without considering sufficiently the pattern size and the directionality together. Based on planar characteristics defined in mechanics such as centroid, moment of inertia, product of inertia, principal axes and so on, vector analysis theory on landscape pattern (VATLP) is explored here. Firstly we establish a coordinate system of centroidal principal axes (CSCPA) of a patch or patches. Some related new indices including those describing the direction of pattern distribution (patch orientation (PO), vectorial patch orientation (VPO)), and those indicating the shape of patch' s equivalent ellipse ( major axis (MJA), minor axis (MIA) and eccentric rate (ER)) are deduced. These landscape metrics are then applied to the pattern analysis of Sanjiang plain marsh, the study area. Two temporal vector-based data sets of the study area come from interpretation of remote sensing images MSS (1980) and TM (2000). The application of the theory captures some shape properties of riparian wetland in Sanjiang plain marsh. The dissymmetrieal featires of Sanjiang plain marsh around principal axes due to agricultural development could also be explained. 展开更多
关键词 三江平原 湿地 向量分析理论 生态系统 VATLP
下载PDF
An Inverse Analysis of the Comprehensive Medium Parameters and a Simulation of the Crustal Deformation of the Qinghai-Tibet Plateau 被引量:3
17
作者 杨志强 陈建兵 +1 位作者 巨天乙 李天文 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第6期1250-1257,共8页
sedonthetheoryoffiniteelementanalysis,aninverseanalysismodelforthecomprehensivemediumparametersoftheQinghai-TibetPlateauissetup.WiththehelpofGPSvelocityfield,thecomprehensivecrustalmediumparametersoftheplateauareinver... sedonthetheoryoffiniteelementanalysis,aninverseanalysismodelforthecomprehensivemediumparametersoftheQinghai-TibetPlateauissetup.WiththehelpofGPSvelocityfield,thecomprehensivecrustalmediumparametersoftheplateauareinverselyanalyzedandthecharacteristicsoftherelatedmovementmacroscopicallysimulated.ItisthenconcludedthatthetectonicdeformationoftheplateauismainlyintheformofaN-ScompressionaccompaniedbyanE-Wstretching,andthepresenttectonicsettingoftheplateaushouldbetheresultofthecollisionbetweentheIndianandtheEurasiancontinentsduringtheCenozoic. 展开更多
关键词 Qinghai-Tibet Plateau medium parameter inverse analysis on displacement SIMULATION tectonic deformation
下载PDF
Image texture indices and trend analysis for forest disturbance assessment under wood harvest regimes
18
作者 Abdolrassoul Salmanmahiny Malihe Erfani +1 位作者 Afshin Danehkar Vahid Etemad 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第2期579-587,共9页
Effective disturbance indices for Hyrcanian forests in Kheyroud,Nowshahr,Iran were determined.The study area was divided into landscape mosaics based on ecosystem parameters including profile type,slope and elevation.... Effective disturbance indices for Hyrcanian forests in Kheyroud,Nowshahr,Iran were determined.The study area was divided into landscape mosaics based on ecosystem parameters including profile type,slope and elevation.Co-occurrence texture indices were derived as forest disturbance factors on the first five bands of Landsat TM,ETM+and OLI images for the prevailing wood harvest disturbance regimes.These indices were screened using ten types of trend analyses and used for modeling disturbance of the harvesting regime through artificial neural networks.The results show that the selected indices can be useful in distinguishing areas with different disturbance intensities and as such,used in the context of health assessment through the health distance method.The accuracy of the health maps derived from the indices[increasing disturbance]led to give rise higher disturbance classification accuracy. 展开更多
关键词 Ecosystem health DISTURBANCE Trend analysis co-occurrence texture indices Landscape mosaics
下载PDF
Content analysis of documents using neural networks: A study of Antarctic science research articles published in international journals
19
作者 DASTIDAR Prabir G JHA, Deepak Kumal 《Advances in Polar Science》 2012年第1期41-46,共6页
Content analysis of scientific papers emanating from Antarctic science research during the 25 years period (1980-- 2004) has been carried out using neural network based algorithm-CATPAC. A total of 10 942 research a... Content analysis of scientific papers emanating from Antarctic science research during the 25 years period (1980-- 2004) has been carried out using neural network based algorithm-CATPAC. A total of 10 942 research articles published in Science Citation Indexed (SCI) journals were used for the study. Normalized co-word matrix from 35 most-used significant words was used to study the semantic association between the words. Structural Equivalence blocks were constructed from these 35 most-used words. Four-block model solution was found to be optimum. The density table was dichotomized using the mean density of the table to derive the binary matrix, which was used to construct the network map. Network maps represent the thematic character of the blocks. The blocks showed preferred connection in establishing semantic relationship with the blocks, characterizing thematic composition of Antarctic science research. The analysis has provided an analytical framework for carrying out studies on the con- tent of scientific articles. The paper has shown the utility of co-word analysis in highlighting the important areas of research in Antarctic science. 展开更多
关键词 ANTARCTICA content analysis thematic analysis SCIENTOMETRICS neural network co-occurrence co-word social network analysis
下载PDF
Visualization Analysis for China’s Business Schools Accreditation Studies Based on Knowledge Mapping
20
作者 Pengbin Gao Yiduo Song Xue Li 《教育研究前沿(中英文版)》 2019年第4期250-256,共7页
The aim of the paper is to identify and explore leading thematic areas within the research field related to Business Schools Accreditation in China.Based on data from the China National Knowledge Infrastructure(CNKI)d... The aim of the paper is to identify and explore leading thematic areas within the research field related to Business Schools Accreditation in China.Based on data from the China National Knowledge Infrastructure(CNKI)database,the keywords frequency was analyzed,and the theory of mapping knowledge domain was used to visualize the keywords co-occurrence network to make further research of the heated issues.The findings indicate that the research scope involved in business school accreditation research is broad,and research content focus on teaching,management,talent cultivation.According to the results of keywords co-occurrence analysis of different stages,AACSB,AACSB Accreditation,international accreditation,business school,AOL,internationalization,accreditation are the most important issues to business school research in China,given their position and role in the research network.The paper generates the added value mainly from the point of view of theory development. 展开更多
关键词 Business School Accreditation China Knowledge Mapping Visualization analysis keyword co-occurrence
下载PDF
上一页 1 2 49 下一页 到第
使用帮助 返回顶部