检索结果-南通市图书馆

Bibliometrics and Network Analysis of Cryptocurrency Research

Journal of Systems Science & Complexity 2020年第6期33卷 1933-1958页

作者： GUO Xiaochun donev.Petko Sino-Danish Center University of Chinese Academy of ScienceBeijingChina Department of Management Politics and PhilosophyCopenhagen Business SchoolPorcelaenshauen 18BCopenhagenDenmark Department of Economics and Management Aalborg UniversityFredrik Bajers Vej 5AalborgDenmark

Cryptocurrency, as an emerging social phenomenon, has attracted great research attentions and starts to form a new research area in the past decade. A thorough review of the existing cryptocurrency literatures helps us to understand the status-quo and the promising research future of this emerging field. This paper provides a systematic review of the cryptocurrency literatures by employing bibliometrics and network analysis methods. A total of 833 publications from Web of Science Core Collection and Scopus have been collected in the time period of January 2008 to June 2018. We examine the descriptive features, countries’ contributions and collaboration networks, author collaboration networks and reference co-citation networks to identify actors with significant influence in this field. The results show that cryptocurrency research is experiencing exponential growth, but scientific collaborations between different countries and authors are still insufficient. The intellectual bases of the cryptocurrency domain rest on the early-year literatures that provide fundamental understandings for cryptocurrency, and that bridge different research fields. The analysis indicates that the current research trend focuses on cryptocurrency market analysis incorporating market behaviors and trading characteristics.

关键词： Bibliometrics Bitcoin cryptocurrency literature review network analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International scientific communications in the field of colorectal tumour markers

引用

World Journal of Gastrointestinal Surgery 2017年第5期9卷 127-138页

作者： Krasimir Ivanov Ivan donev Department of General and Operative Surgery Professor Paraskev Stoyanov Medical University of Varna Clinic of Medical Oncology St. Marina University Hospital of Varna

AIM To analyze scientometrically the dynamic science internationalization on colorectal tumour markers as reflected in five information portals and to outline the significant journals, scientists and *** A retrospective problem-oriented search was performed in Web of Science Core Collection(Wo S), MEDLINE, BIOSIS Citation Index(BIOSIS) and Scopus for 1986-2015 as well as in Dervent Innovations Index(Derwent) for 1995-2015. Several specific scientometric parameters of the publication output and citation activity were comparatively analyzed. The following scientometric parameters were analyzed:(1) annual dynamics of publications;(2) scientific institutions;(3) journals;(4) authors;(5) scientific forums;(6) patents-number of patents, names and countries of inventors, and(7) citations(number of citations to publications by single authors received in WoS, BIOSIS Citation Index and Scopus).RESULts There is a trend towards increasing publication output on colorectal tumour markers worldwide along with high citation rates. Authors from 70 countries have published their research results in journals and conference proceedings in 21 languages. There is considerable country stratification similar to that in most systematic investigations. The information provided to end users and scientometricians varies between these data-bases in terms of most parameters due to different journal coverage, indexing systems and editorial policy. The lists of the so-called "core" journals and most productive authors in Wo S, BIOSIS, MEDLINE and Scopus along with the list of the most productive authors-inventors in Derwent present a particular interest to the beginners in the field, the institutional and national science managers and the journal editorial board members. The role of the purposeful assessment of scientific forums and patents is emphasized. CONCLUSION Our results along with this problem-oriented collection containing the researchers' names, addresses and publication

关键词： Colorectal tumour markers Scientometrics International scientific communications Web of Science MEDLINE BIOSIS Scopus Derwent

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Estimating the Forest Above-ground Biomass Based on Extracted LiDAR Metrics and Predicted Diameter at Breast Height

引用

Journal of Geodesy and Geoinformation Science 2021年第3期4卷 13-24页

作者： Petar donev.Hong WANG Shuhong QIN Pengyu MENG Jinbo LU School of Hydrology and Water Resources Hohai UniversityNanjing 210098China School of Earth Sciences and Engi-neering Hohai UniversityNanjing 210098China

Reliable and prompt information on forest above-ground biomass(AGB)and tree diameter at breast height(DBH)are crucial for sustainable forest *** sensing technology,especially the Light Detection and Ranging(LiDAR)technology,has been proven to estimate important tree variables *** study proposes predicting DBH and AGB from tree height and other LiDAR data extracted *** the suggested DBH prediction,we developed a nonlinear estimation equation using the total tree *** for the AGB prediction approach,we used regression methods such as multiple linear regression(MLR),random forest(RF)and support vector machine for regression(SVR).We conducted the study for the Gudao forest area dominated by Robinia Pseudoacacia trees,located in the Yellow River Delta(YRD),*** our developed approaches,we used Unmanned Aerial Vehicle(UAV)and Backpack LiDAR point cloud datasets obtained in June 2017,and three field data measurements gathered in June 2017 and 2019 and October 2019,all from the same study *** results demonstrate that:①The LiDAR data individual tree segmentation(Its)from which we extracted individual tree information like tree location and tree height,was carried out with an overall accuracy F=0.91;②We used the Its height data from the field stand in 2019 as a fit and developed a nonlinear DBH estimation equation with Root Mean Square Error(RMSE)=3.61 cm,later validated by the 2017 dataset;③Forest AGB at stand level was estimated with the MLR,RF and also SVR regression methods,and results show that the SVR method gave higher accuracy with R2=0.82 compared to the R2=0.72 of RF and the R2=0.70 of the *** AGB at plot level using the 2017 LiDAR data was used to validate both models’*** the UAV LiDAR data and the Backpack LiDAR significantly improved the overall *** UAV LiDAR ability to provide high accuracy tree height abstraction,the DBH of the regression equation and other extracted LiDAR metrics sh

关键词： forest AGB DBH estimation UAV LiDAR Backpack LiDAR

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Efficient Variable-Coefficient Finite-Volume Stokes Solvers

引用

Communications in Computational Physics 2014年第10期16卷 1263-1297页

作者： Mingchao Cai Andy Nonaka John B.Bell Boyce E.Griffith Aleksandar donev Courant Institute of Mathematical Sciences New York UniversityNew YorkNY 10012USA. Center for Computational Sciences and Engineering Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA. Leon H.Charney Division of Cardiology Department of MedicineNew York University School of MedicineNYUSA. Department of Mathematics University of North CarolinaChapel HillNC 27599USA

We investigate several robust preconditioners for solving the saddle-point linear systems that arise from spatial discretization of unsteady and steady variablecoefficient Stokes equations on a uniform staggered *** on the success of using the classical projection method as a preconditioner for the coupled velocitypressure system[***,***.,228(2009),pp.7565–7595],as well as established techniques for steady and unsteady Stokes flow in the finite-element literature,we construct preconditioners that employ independent generalized Helmholtz and Poisson solvers for the velocity and pressure *** demonstrate that only a single cycle of a standard geometric multigrid algorithm serves as an effective inexact solver for each of these *** to traditional wisdom,we find that the Stokes problem can be solved nearly as efficiently as the independent pressure and velocity subproblems,making the overall cost of solving the Stokes system comparable to the cost of classical projection or fractional step methods for incompressible flow,even for steady flow and in the presence of large density and viscosity *** of the five preconditioners considered here are found to be robust to GMRES restarts and to increasing problem size,making them suitable for large-scale *** work opens many possibilities for constructing novel unsplit temporal integrators for finite-volume spatial discretizations of the equations of low Mach and incompressible flow dynamics.

关键词： Stokes flow variable density variable viscosity saddle point problems projection method preconditioning GMRES.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

BOUNDARY LAYER GROWTH AND LAPSE RATE CHANGES DETERMINED BY LIDAR AND SURFACE HEAT FLUX IN SOFIA

引用

Acta meteorologica Sinica 1995年第1期9卷 101-111页

作者： E.donev.K.Zeller St.Panchev I.Kolev Department of Meteorology Faculty of PhysicsSofia UniversityBulgaria USDA Forest Service Rocky Mountain Forest and Range Experiment StationFort CollinsColoradoUSA Institute of Electronics Bulgarian Academy of SciencesBulgaria

In this study the results from a boundary layer experiment,conducted in autumn 1991 over a flat,build-up urban area in Southeast Sofia,together with some models for mixed layer growth rates are used to investigate the layered struc- ture of the vertical atmospheric stability distribution in the Sofia *** measurements of aerosol layer heights and morning boundary layer development are combined with surface eddy correlation measurements of kinematic heat and moisture fluxes,profiles of temperature and humidity,wind speed and wind direction.A diagnostic method is pres- ented for determining vertical lapse rates using surface meteorological measurements and lidar returns observed during the transition from nighttime stable stratification to daytime convective boundary layer after the sunrise.

关键词： convective boundary layer lidar heat flux lapse rate

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：