Mobile Cloud Computing : A Scientometric Assessment of Global Publications Output during 2007-16

Copyright © The Author(s). 2017 This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. ABSTRACT The paper examines 3779 global publications on mobile cloud computing research, as covered in Scopus database during 2007-16, experiencing an annual average growth rate of 139.6% and qualitative impact averaged to 4.22 citations per paper. The top 10 most productive countries individually contributed global share from 2.91% to 22.41%, with largest global publication share coming from China (22.41%), followed by USA (19.32%), etc. Together, the 10 most productive countries accounted for 85.74% share of global publication output during 2007-16. Five out of 10 countries have scored relative citation index above the world average of 1: Malaysia (2.41), USA (1.87), U.K. (1.79), Canada (1.43) and Italy (1.16) during 2007-16. The international collaborative publications share of top 10 most productive countries varied from 9.74% to 67.19% in mobile cloud computing research during 2007-16. Computer Science, among subjects, contributed the largest publication share (85.79%), followed by engineering (28.37%), mathematics and social sciences (10.64% and 5.58%) etc. during 2007-16. The top 20 most productive organizations and authors together contributed 18.92% and 9.98% respectively as their share of global publication output and 37.07% and 24.28% respectively as their share of global citation output during 2007-16. Among the total journal output of 5673 papers, the top 20 journals contributed 30.01% share to the global journal output during 2007-16. Of the total mobile computing research, the top 15 highly cited publications registered citations from 99 to 848 and they together received 3834 citations, with 255.60 citations per paper. These 15 highly cited papers involved the participation of 26 authors and 27 organizations. These 15 highly cited papers were published in 8 journals, of which 4 papers were published in IEEE Communication Surveys andTutorials, 2 papers in Mobile Networks andApplications, and 1 paper each in other journals.


INTRODUCTION
Cloud computing can be defined as the aggregation of computing services as a utility such as software as a service as you go computing. [1,2,3]In cloud computing the applications are delivered as a service over the internet and the required hardware and systems software that are located in remote data centers provide application services. [2,3]Also called as "on demand computing", "utility computing" or ''pay as you go computing'', the concept underlying cloud computing is to dispense with the need to own a local computation infrastructure, and instead computing research with the related literature during 2007-2013 from the databases of Science Citation Index Expanded (SCI-E), Conference Proceedings Citation Index-Science (CPCI-S), and IEEEXplore.By investigating the characteristics of publications such as keywords, output, geographic distribution, and affiliation, the authors draw some valuable conclusions to guide the further research.Gupta, Singh, and Gupta. [9]And Gupta and Gupta. [10]examined 21397 and 1206 global and Indian publications in cloud computing, as covered in Scopus database during 2004-13, with a view to studying the growth of research output and its distribution by type of publication, contribution and citation impact of top most productive countries, international collaboration share and the extent of inter-country collaborative linkages, the distribution of research output by broad subject areas and identify the important subject keywords to understand trends in research, the publication productivity and citation impact of most productive institutions and authors, leading media of communication and the characteristics of highly cited papers.Amongst mobile related studies, bibliometric studies have conducted in the past on overall mobile research. [11]mobile computing. [12,13,14]mobile learning. [15]mobile banking. [16]and mobile payment. [17]

OBJECTIVES
The main objectives of this study are to study the performance of mobile cloud computing research during 2007-16, based on publications output covered in Scopus database.In particular, the study focuses on the following objectives: To study the growth of world research output in mobile cloud computing research and its citation impact; To study the international collaboration share of top 10 most productive countries; To study the global research output by broad subject areas and the dynamics of its growth and decline; To study the trends in sub-fields by identifying significant keywords; To study the publication productivity and citation impact of top 20 most productive organizations and authors;

To study the modes of communication in research; and
To study the characteristics of top 15 highly cited papers.

METHODOLOGY
The study retrieved and downloaded 10-year publication data of the world output in mobile cloud computing research from the Scopus database (http://www.scopus.com)covering the period 2007-16.Keywords, such as "mobile cloud computing'' or ''m-cloud computing'' or "mcloud computing" were incor-Web Services, and Microsoft Azure.Software as a Service (SaaS) is a software distribution model, the service provider makes applications ready to customers over the internet and it supports Web Services and service-oriented architecture (SOA).Examples include Saleforce.comand IBM Lotus Live.Anything as a Service (Xaas): This refers to the diverse models of information technology-based on-demand services that can be delivered via the cloud computing platform. [4]th an explosive growth in the mobile applications coupled with the emerging cloud computing concept, the Mobile Cloud Computing (MCC) has become a potential technology for the mobile service users.MCC integrates the technology of cloud computing with the mobile environment and that this kind of integration has become the part of a major discussion trends in the IT world since 2009.The ABI Research predicts that the number of mobile cloud computing subscribers is expected to grow from 42.8 million (1.1% of total mobile users) in 2008 to 998 million (19% of total mobile users) in 2014.According to the recent survey conducted by the International Data Corporation, most of IT Executives and CEOs are not interested in adopting such services given the drawbacks associated with mobile cloud computing technology (e.g., battery life, storage, and bandwidth), environment (e.g., heterogeneity, scalability, and availability), and security (e.g., reliability and privacy).In spite of ongoing efforts to overcome these pitfalls, the challenges continue to persist in the security policies of mobile cloud computing. [5]Mobile applications are gaining increasing share in the global mobile market.The cloud computing mobile applications fall in the area of commerce, learning, healthcare, gaming, etc.In addition, a cloud becomes a useful tool to help mobile users share photos and video clips efficiently and tags their friends in popular social networks.A cloud becomes a most effective tool when mobile users require searching services (e.g.searching information, locations, images, voices and video clips). [6]terature Review Only one study is available, which quantitatively analyze global literature on mobile cloud computing.Ibukun and Daramola [7] provided a credible intellectual guide for upcoming researchers in mobile cloud computing (MCC) to help them identify areas in MCC research where they can make the most impact from 2002-2014.The study reveals that privacy, security, and trust in MCC are the least researched, whereas issues of architecture, context awareness and data management have been averagely researched, while issues on operations, end users, service, and applications have received a lot of attention.However, few scientometric studies are available in the area of cloud computing and mobile related research.Amongst cloud computing research studies, Yuanyuan, Lu, Wang and Xing [8] quantitatively reviewed the progress in global cloud porated in the search string and qualified these keywords with "keyword tag", "Article Title tag", and in addition incorporated in this search string the period '2007-16' within "date range tag".Finally, this search string was applied for searching global publication data on mobile cloud computing.The search string was subsequently refined using analytical commands of Scopus database by "subject area tag", "country tag", "source title tag", "journal title name" and "affiliation tag", to get data/ information on the distribution of publications output by subject, collaborating countries, author-wise, organization-wise and journal-wise, etc.For citation data, citations to publications were also collected from date of publication till 29 December 2016.The publications data was analyzed across a few select raw (number of papers and collaborative papers, citation per paper, etc.) and relative bibliometric indicators (such as activity index and relative citation index) with a view to understand the research activity in mobile cloud computing.We have used here complete counting method, where all authors or organizations to multi-authored papers have received equal credit in data counting and analysis.All types of documents have been used in this study.

Analysis
The total research output of the world in field of mobile cloud computing cumulated to 3779 publications in 10

Profile of Top 20 Most Productive Authors
In the field of global mobile cloud computing, the research productivity of top 20 most productive authors varied from 13 to 34 publications.Together they contributed 9.98% (377)

Profile of Top 20 Most Productive Global Organizations
In global mobile cloud computing research, the productivity of 20 most productive global organizations varied from 22 to 89 publications and together they contributed 18.92% (715) publication share and 37.07% (5913) citation share to its cumulative publications output during 2007-16.The scientometric profile of these 20 organizations is presented in

Table 1 .
Top 10 Most Productive Countries in Mobile Cloud ComputingThe global research output in the field of mobile cloud computing had originated from as many as 96 countries in the world during 2007-16.Top 10 most productive countries in mobile cloud computing research had contributed 105 to 847 publications each during 2007-16 Table2.Of the 96 countries, 47 contributed 1-10 papers each, 30 countries 11-50 papers each, 8 countries 51-100 papers each and 11 countries 106-847 papers each.Top 10 most productive countries in mobile The global publication shares in five years increased by 5.79% in India, followed by 3.49% in Canada, 1.99% in Malaysia, 0.59% in China and 0.27% in U.K., as against decrease by 6.03% in USA, 4.38% in Germany, 2.93% in Taiwan, 2.03% in South Korea and 0.36% in Italy from 2007-11 to 2012-16.Five of top 10 countries scored relative citation index above the world average i.e.