Understanding the linkages of smart-city technologies and applications: Key lessons from a text mining approach and a call for future research

There have been many attempts to transform cities into smart cities worldwide. However, it is difficult to understand and describe smart cities from different perspectives, given the widespread application of the concept of smart city in diverse disciplines, such as urban planning, electronic engineering, and computer sciences. This work conducted a comprehensive smart city literature review based on text mining of 3,315 papers on smart cities published in journals indexed in the Science Citation Index Expanded and Social Sciences Citation Index databases. These include "all papers" classified as research articles published from 1999 to April 2020. Our findings show the state of the art of research on smart cities, including (i) smart city literature statistics from 1999 to 2019, (ii) 23 research topics related to smart cities, and (iii) geographical variations in smart-city research. Based on these findings, we offer theoretical and practical implications of (1) missing fields of studies, (2) future research directions, and (3) the applicability of text-mining techniques to literature reviews. We believe that this work, which aims to establish a common ground for understanding smart cities from multiple disciplinary perspectives, will encourage further research and development regarding smart cities.