Table 3 Research themes
Year | Conceptual evolution | Feasibility analysis | Technological advancement |
|---|---|---|---|
2013 | 1 | 0 | 0 |
2014 | 0 | 0 | 0 |
2015 | 2 | 2 | 0 |
2016 | 0 | 1 | 0 |
2017 | 0 | 1 | 0 |
2018 | 1 | 0 | 0 |
2019 | 1 | 0 | 0 |
2020 | 2 | 2 | 2 |
2021 | 0 | 1 | 3 |
2022 | 0 | 1 | 2 |
Total | 7 | 8 | 7 |
Year | Conceptual evolution | Feasibility analysis | Technological advancement |
|---|---|---|---|
2013 | 1 | 0 | 0 |
2014 | 0 | 0 | 0 |
2015 | 2 | 2 | 0 |
2016 | 0 | 1 | 0 |
2017 | 0 | 1 | 0 |
2018 | 1 | 0 | 0 |
2019 | 1 | 0 | 0 |
2020 | 2 | 2 | 2 |
2021 | 0 | 1 | 3 |
2022 | 0 | 1 | 2 |
Total | 7 | 8 | 7 |