# Best-Suited Communication Technology for Maritime Signaling Facilities: A Literature Review
## 3 Results and Discussion
### Analytical Literature Review  
In Figure 2, a total of 43 papers that met the specified search criteria were identified during the search in the WOS scientific database. Onward, searching the SCOPUS database using Table 1, from 2003 to 2023, a total of 131 papers were found. Also, the search of the same period in the GOOGLE SCHOLAR database resulted in 21 papers that met the specific criteria from the table. Searching other databases provided 19 additional relevant scientific papers. The time scale of analyzed papers and basic statistical metrics for each database is shown in Table 2.  
A basic statistical analysis was performed on columns to check the data from the table. A Kolmogorov-Smirnov test was performed to check the data normality. It showed that data do not come from the normal distribution (P\({}_{\text{WOS}}\) < 0.001, P\({}_{\text{SCOPUS}}\) < 0.001, P\({}_{\text{GOOGLE}}\) < 0.001, and p\({}_{\text{OTHER}}\) < 0.001). Then, a Kruskal-Wallis ANOVA test was performed to check  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{5}{c}{**SCIENTIFIC DATABASES**} \\ \hline
**Obs. Years** & **WOS** & **SCOPUS** & \multicolumn{2}{c}{**GOOGLE**} & \multirow{2}{*}{**OTHER**} \\ \hline
2003 & 0 (0) & 0 (0) & 0 (0) & 0 (0) \\
2004 & 0 (0) & 1 (0) & 0 (0) & 0 (0) \\
2005 & 1 (0) & 5 (0) & 2 (0) & 0 (0) \\
2006 & 2 (  
the data's independence between the columns. It showed \(\chi^{2}(3)=29.37\), \(p<0.001\). Thus, it can be noted that the data do not come from the same source. In the first stage, \"document identification\", only 20% of the papers met the specified search criteria in the WOS database. During the 21 years, the median is one paper per year with a standard deviation of 2.44. The most productive year, with eight published papers, was 2019 (Table 2). Furthermore, a search of the SCOPUS database from 2003 to 2023 yielded 131 papers, or 61,21%. Contrary to the WOS database, the median was five papers per year, with a standard deviation of 4.89. Similarly, to the WOS, the year with the highest number of published papers, 22, was also 2019. The GOOGLE SCHOLAR database search resulted in 21 papers, or 9.81%, during the same period (Table 2). Similarly as WOS, the median is one published paper per year with a standard deviation of 1.27. However, 2018 was the year with the highest number of published papers. Moreover, a paper search in other databases was performed, and 19 relevant scientific papers, or 8.88%, were identified. The median is 0, with a standard deviation of 1.11 papers per year. Unlike the WOS and SCOPUS databases, the highest number of papers, four, were published in 2022. To summarize, the processed data from Table 2 show that interest in the topic has noticeably increased in the last six years compared to the observed period. This increase is graphically represented in Figure 3.  
Figure 3 shows that the number of papers on the topic has increased from 2018 until today. For instance, in 2018, 24 papers were published, which is three times less than in 2005, when a total of 8 papers were published, or eight times more than the previous year, when only 1 paper on this topic was published. Additionally, the number of papers peaked in 2019, with 34 papers published. Furthermore, the filtering criteria applied in the \"Document screening\" stage were as follows: (1) Duplicates, identified through manual comparison of titles, authors, and publication sources, with preference given to versions from Web of Science or Scopus; (2) Papers unrelated to the review's subject (e.g., meteorological measurements on buoys, buoy-related energy); (3) Papers encompassing extensive research areas (e.g., analysis of communication antenna systems, antenna system optimization, satellite communication); and (4) Papers in languages other than English or Croatian. Due to resource constraints and the research team's language expertise, we focused on articles published in English and Croatian.