## 4 Bibliometric Analysis
### Influential journals, Authors, and Countries
#### 4.2.3 The Most Productive Countries  
In this subsection, the authors aim to investigate the most prominent countries in the field of research on image-based crack detection methods for roads. The analysis of the 305 papers filtered from the Scopus dataset revealed a total of 43 countries. Figure 5 shows the distribution of these 305 papers. In this figure, larger circles indicate that more papers have been published in that country. The authors analyzed the contribution of each continent in terms of published papers, with Asia having the highest contribution, publishing 63.24% of the total number of papers. North America and Europe accounted for 17.40% and 13.73% of the total number of papers, respectively, while the remaining 5.63% came from other regions of the world. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & **Author Name** & \begin{tabular}{c} **Total** \\ **Publications** \\ \end{tabular} & \begin{tabular}{c} **Total** \\ **Citations** \\ \end{tabular} & \begin{tabular}{c} **Average** \\ **Citations** \\ \end{tabular} & \begin{tabular}{c} **As 1 st** \\ **Author** \\ \end{tabular} & **H-Index** & **Country** \\ \hline \multirow{4}{*}{\
\begin{tabular}{c} **Based on** \\ **Publications** \\ \end{tabular} } & [PERSON] & 15 & 489 & 9.65 & 5 & 9 & China \\ \cline{2-8}  & [PERSON] & 13 & 447 & 8.63 & 4 & 8 & China \\ \cline{2-8}  & [PERSON], Kelvin C.P. & 9 & 1378 & 26.18 & 0 & 7 & USA \\ \cline{2-8}  & [PERSON] & 9 & 348 & 21.63 & 0 & 7 & China \\ \cline{2-8}  & [PERSON] & 8 & 113 & 4.52 & 6 & 4 & China \\ \hline \multirow{4}{*}{
\begin{tabular}{c} **Based on** \\ **Citations** \\ \end{tabular} } & [PERSON], Kelvin C.P. & 9 & 1378 & 26.18 & 0 & 7 & USA \\ \cline{2-8}  & [PERSON] & 7 & 1373 & 37.89 & 3 & 7 & China \\ \cline{2-8}  & [PERSON] & 6 & 1345 & 38.35 & 4 & 6 & USA \\ \cline{2-8}  & [PERSON] & 5 & 1319 & 45.36 & 1 & 5 & USA \\ \cline{2-8}  & [PERSON] [PERSON]. & 4 & 1281 & 53.31 & 0 & 4 & USA \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Summary of the most productive authors. After showing the geographical distribution of the papers in the dataset, the authors present the top 10 papers by number of publications in Table 6. Table 6 shows information on country, total publications, total citations, average citations, number of cited papers greater than or equal to 100/50/30/10, and H-index, arranged based on the number of papers published in each country. From Table 6, China is far ahead of other countries with a total of 203 papers, 6749 total citations, and an amazing H-index of 41. Although the United States is not as good as China in terms of number of publications or citations, it is in first place in terms of average citations (21.10). Both China and the United States have more than 10 papers with more than 100 citations. With 18 papers, Canada and the United Kingdom are tied for third place, but Canada's total citations of 776 are significantly higher than the United Kingdom's 338, Canada has 6 papers with more than 50 citations, while the United Kingdom has none. The authors also found that there are some countries in the dataset that do not appear in the top 10, but their papers received a high number of citations, indicating that the papers published in these countries also have a high impact. For example, in the dataset, Portugal has only three papers with 454 citations, and Malaysia has only three papers with 221 citations. These two countries have even more total citations than some of the top 10 countries.