Machine Learning in International Finance and Trade: Presidential Address

# Machine Learning in International Finance and Trade: Presidential Address - ITFA 2021
### Thierry Warin, PhD

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# Outline

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### Outline

1. Methodology

2. Descriptive statistics

3. Conceptual structures

4. Social structures

5. Conclusion

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class: inverse, center, middle

# 1. Methodology

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### 1. Methodology

> Research Question: When have we started to talk about machine learning in international trade and finance?

- Warin Th. (2020) “Global Research on Coronaviruses: An R Package”, J Med Internet Res, Vol. 22, No. 8, August, 2020

- Sanger W. and Warin Th. (2020) “How Data Science can (also) help central bankers: An NLP study of the European Central Bank presidents’ speeches” Global Economy Journal, Vol. 20, No. 02, 2050009

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### 1. Methodology

- Metadata-Based systematic literature review:

- What is it?

- Why can it be useful?

---

### 1. Methodology

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---

### 1. Methodology

Analytics and Graphs for three different level metrics:

- Sources (local and global citations)

- Authors

- Documents

Three structures of Knowledge (K-structures):

- Conceptual Structures

- Intellectual Structures

- Social Structures

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### 1. Methodology

Aria, M., Misuraca, M., & Spano, M. (2020). Mapping the evolution of social research and data science on 30 years of Social Indicators Research. Social Indicators Research, 1-29, DOI: 10.1007/s11205-020-02281-3.

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# 2. Descriptive Statistics

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###  2. Descriptive Statistics

* The relevant 'universe' of the literature consists of 2,563 references identified in the Web of Science citation database (see Table 1), most of which are published in refereed journals (see Table 2). The literature review covers the period between January 1, 1990, and May 26, 2021.

* The overall number of documents in our sample is 2,563 (see Table 1). This number is the cumulative result of each year, and we can observe a significant rise in the number of documents per year. The average citations per document are 12.6 but have evolved through time.

* The number of articles dominates the sample for the overall period (see Table 2) with 1,414 occurrences, followed by 976 proceedings papers.

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### Descriptive Statistics

<div class="figure" style="text-align: center">
<img src="./figures/figure1.png" alt="Articles count through time" width="50%" />
<p class="caption">Articles count through time</p>
</div>

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<table class=" lightable-classic" style='font-family: "Arial Narrow", "Source Sans Pro", sans-serif; margin-left: auto; margin-right: auto;'>
<caption>Preliminary information about data, overall period, and per year</caption>
 <thead>
  <tr>
   <th style="text-align:left;"> Description </th>
   <th style="text-align:left;"> Overall Time Period </th>
   <th style="text-align:left;"> 2017 </th>
   <th style="text-align:left;"> 2018 </th>
   <th style="text-align:left;"> 2019 </th>
   <th style="text-align:left;"> 2020 </th>
   <th style="text-align:left;"> 2021 </th>
  </tr>
 </thead>
<tbody>
  <tr>
   <td style="text-align:left;"> Timespan </td>
   <td style="text-align:left;"> 1991:2021 </td>
   <td style="text-align:left;"> 2017:2017 </td>
   <td style="text-align:left;"> 2018:2018 </td>
   <td style="text-align:left;"> 2019:2019 </td>
   <td style="text-align:left;"> 2020:2020 </td>
   <td style="text-align:left;"> 2021:2021 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Sources (Journals, Books, etc) </td>
   <td style="text-align:left;"> 1594 </td>
   <td style="text-align:left;"> 206 </td>
   <td style="text-align:left;"> 261 </td>
   <td style="text-align:left;"> 375 </td>
   <td style="text-align:left;"> 357 </td>
   <td style="text-align:left;"> 142 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Documents </td>
   <td style="text-align:left;"> 2563 </td>
   <td style="text-align:left;"> 239 </td>
   <td style="text-align:left;"> 324 </td>
   <td style="text-align:left;"> 508 </td>
   <td style="text-align:left;"> 531 </td>
   <td style="text-align:left;"> 182 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Average years from publication </td>
   <td style="text-align:left;"> 4.21 </td>
   <td style="text-align:left;"> 4 </td>
   <td style="text-align:left;"> 3 </td>
   <td style="text-align:left;"> 2 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Average citations per documents </td>
   <td style="text-align:left;"> 12.6 </td>
   <td style="text-align:left;"> 13.08 </td>
   <td style="text-align:left;"> 8.528 </td>
   <td style="text-align:left;"> 6.463 </td>
   <td style="text-align:left;"> 2.399 </td>
   <td style="text-align:left;"> 1.011 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Average citations per year per doc </td>
   <td style="text-align:left;"> 2.097 </td>
   <td style="text-align:left;"> 2.615 </td>
   <td style="text-align:left;"> 2.132 </td>
   <td style="text-align:left;"> 2.154 </td>
   <td style="text-align:left;"> 1.2 </td>
   <td style="text-align:left;"> 1.011 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> References </td>
   <td style="text-align:left;"> 83779 </td>
   <td style="text-align:left;"> 7846 </td>
   <td style="text-align:left;"> 10798 </td>
   <td style="text-align:left;"> 18305 </td>
   <td style="text-align:left;"> 23575 </td>
   <td style="text-align:left;"> 10024 </td>
  </tr>
</tbody>
</table>

]

<table class=" lightable-classic" style='font-family: "Arial Narrow", "Source Sans Pro", sans-serif; margin-left: auto; margin-right: auto;'>
<caption>Document type, overall period, and per year</caption>
 <thead>
  <tr>
   <th style="text-align:left;"> Description </th>
   <th style="text-align:left;"> Overall Time Period </th>
   <th style="text-align:left;"> 2017 </th>
   <th style="text-align:left;"> 2018 </th>
   <th style="text-align:left;"> 2019 </th>
   <th style="text-align:left;"> 2020 </th>
   <th style="text-align:left;"> 2021 </th>
  </tr>
 </thead>
<tbody>
  <tr>
   <td style="text-align:left;"> Article </td>
   <td style="text-align:left;"> 1414 </td>
   <td style="text-align:left;"> 111 </td>
   <td style="text-align:left;"> 158 </td>
   <td style="text-align:left;"> 251 </td>
   <td style="text-align:left;"> 389 </td>
   <td style="text-align:left;"> 167 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Article; book chapter </td>
   <td style="text-align:left;"> 2 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 1 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Article; data paper </td>
   <td style="text-align:left;"> 3 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 2 </td>
   <td style="text-align:left;"> 0 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Article; early access </td>
   <td style="text-align:left;"> 45 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Article; proceedings paper </td>
   <td style="text-align:left;"> 59 </td>
   <td style="text-align:left;"> 2 </td>
   <td style="text-align:left;"> 3 </td>
   <td style="text-align:left;"> 6 </td>
   <td style="text-align:left;"> 5 </td>
   <td style="text-align:left;"> 1 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Correction </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Editorial material </td>
   <td style="text-align:left;"> 3 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 1 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Editorial material; early access </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Letter </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Meeting abstract </td>
   <td style="text-align:left;"> 2 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Note </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Proceedings paper </td>
   <td style="text-align:left;"> 976 </td>
   <td style="text-align:left;"> 123 </td>
   <td style="text-align:left;"> 157 </td>
   <td style="text-align:left;"> 238 </td>
   <td style="text-align:left;"> 113 </td>
   <td style="text-align:left;"> 0 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Reprint </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Review </td>
   <td style="text-align:left;"> 50 </td>
   <td style="text-align:left;"> 2 </td>
   <td style="text-align:left;"> 2 </td>
   <td style="text-align:left;"> 11 </td>
   <td style="text-align:left;"> 20 </td>
   <td style="text-align:left;"> 11 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Review; book chapter </td>
   <td style="text-align:left;"> 2 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 1 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Review; early access </td>
   <td style="text-align:left;"> 2 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
   <td style="text-align:left;"> 0 </td>
  </tr>
</tbody>
</table>

]

<table class=" lightable-classic" style='font-family: "Arial Narrow", "Source Sans Pro", sans-serif; margin-left: auto; margin-right: auto;'>
<caption>Document content and authors, overall period, and per year</caption>
 <thead>
  <tr>
   <th style="text-align:left;">   </th>
   <th style="text-align:left;"> Description </th>
   <th style="text-align:left;"> Overall Time Period </th>
   <th style="text-align:left;"> 2017 </th>
   <th style="text-align:left;"> 2018 </th>
   <th style="text-align:left;"> 2019 </th>
   <th style="text-align:left;"> 2020 </th>
   <th style="text-align:left;"> 2021 </th>
  </tr>
 </thead>
<tbody>
  <tr>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> Keywords Plus (ID) </td>
   <td style="text-align:left;"> 3094 </td>
   <td style="text-align:left;"> 406 </td>
   <td style="text-align:left;"> 542 </td>
   <td style="text-align:left;"> 832 </td>
   <td style="text-align:left;"> 1126 </td>
   <td style="text-align:left;"> 290 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> 2 </td>
   <td style="text-align:left;"> Author's Keywords (DE) </td>
   <td style="text-align:left;"> 7031 </td>
   <td style="text-align:left;"> 825 </td>
   <td style="text-align:left;"> 1052 </td>
   <td style="text-align:left;"> 1747 </td>
   <td style="text-align:left;"> 2224 </td>
   <td style="text-align:left;"> 904 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> 4 </td>
   <td style="text-align:left;"> Authors </td>
   <td style="text-align:left;"> 7627 </td>
   <td style="text-align:left;"> 835 </td>
   <td style="text-align:left;"> 1126 </td>
   <td style="text-align:left;"> 1866 </td>
   <td style="text-align:left;"> 1813 </td>
   <td style="text-align:left;"> 663 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> 5 </td>
   <td style="text-align:left;"> Author Appearances </td>
   <td style="text-align:left;"> 9444 </td>
   <td style="text-align:left;"> 869 </td>
   <td style="text-align:left;"> 1208 </td>
   <td style="text-align:left;"> 2025 </td>
   <td style="text-align:left;"> 1989 </td>
   <td style="text-align:left;"> 693 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> 6 </td>
   <td style="text-align:left;"> Authors of single-authored documents </td>
   <td style="text-align:left;"> 135 </td>
   <td style="text-align:left;"> 9 </td>
   <td style="text-align:left;"> 12 </td>
   <td style="text-align:left;"> 22 </td>
   <td style="text-align:left;"> 32 </td>
   <td style="text-align:left;"> 10 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> 7 </td>
   <td style="text-align:left;"> Authors of multi-authored documents </td>
   <td style="text-align:left;"> 7492 </td>
   <td style="text-align:left;"> 826 </td>
   <td style="text-align:left;"> 1114 </td>
   <td style="text-align:left;"> 1844 </td>
   <td style="text-align:left;"> 1781 </td>
   <td style="text-align:left;"> 653 </td>
  </tr>
</tbody>
</table>
       
]

<table class=" lightable-classic" style='font-family: "Arial Narrow", "Source Sans Pro", sans-serif; margin-left: auto; margin-right: auto;'>
<caption>Authors Collaboration</caption>
 <thead>
  <tr>
   <th style="text-align:left;"> Description </th>
   <th style="text-align:left;"> Overall Time Period </th>
   <th style="text-align:left;"> 2017 </th>
   <th style="text-align:left;"> 2018 </th>
   <th style="text-align:left;"> 2019 </th>
   <th style="text-align:left;"> 2020 </th>
   <th style="text-align:left;"> 2021 </th>
  </tr>
 </thead>
<tbody>
  <tr>
   <td style="text-align:left;"> Single-authored documents </td>
   <td style="text-align:left;"> 137 </td>
   <td style="text-align:left;"> 9 </td>
   <td style="text-align:left;"> 12 </td>
   <td style="text-align:left;"> 22 </td>
   <td style="text-align:left;"> 32 </td>
   <td style="text-align:left;"> 10 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Documents per Author </td>
   <td style="text-align:left;"> 0.336 </td>
   <td style="text-align:left;"> 0.286 </td>
   <td style="text-align:left;"> 0.288 </td>
   <td style="text-align:left;"> 0.272 </td>
   <td style="text-align:left;"> 0.293 </td>
   <td style="text-align:left;"> 0.275 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Authors per Document </td>
   <td style="text-align:left;"> 2.98 </td>
   <td style="text-align:left;"> 3.49 </td>
   <td style="text-align:left;"> 3.48 </td>
   <td style="text-align:left;"> 3.67 </td>
   <td style="text-align:left;"> 3.41 </td>
   <td style="text-align:left;"> 3.64 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Co-Authors per Documents </td>
   <td style="text-align:left;"> 3.68 </td>
   <td style="text-align:left;"> 3.64 </td>
   <td style="text-align:left;"> 3.73 </td>
   <td style="text-align:left;"> 3.99 </td>
   <td style="text-align:left;"> 3.75 </td>
   <td style="text-align:left;"> 3.81 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Collaboration Index </td>
   <td style="text-align:left;"> 3.09 </td>
   <td style="text-align:left;"> 3.59 </td>
   <td style="text-align:left;"> 3.57 </td>
   <td style="text-align:left;"> 3.79 </td>
   <td style="text-align:left;"> 3.57 </td>
   <td style="text-align:left;"> 3.8 </td>
  </tr>
</tbody>
</table>

]

---
class: inverse, middle, center

# 3. Conceptual structures

---
class: center, middle

# Keywords

---

<div style="border: 1px solid #ddd; padding: 0px; overflow-y: scroll; height:400px; overflow-x: scroll; width:100%; "><table class=" lightable-classic" style='font-family: "Arial Narrow", "Source Sans Pro", sans-serif; margin-left: auto; margin-right: auto;'>
<caption>Most Relevant Keywords</caption>
 <thead>
  <tr>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> Author Keywords (DE) </th>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> Articles </th>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> Keywords-Plus (ID) </th>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> Articles </th>
  </tr>
 </thead>
<tbody>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>Overall Time Period</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Machine Learning </td>
   <td style="text-align:left;"> 867 </td>
   <td style="text-align:left;"> Classification </td>
   <td style="text-align:left;"> 131 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Learning </td>
   <td style="text-align:left;"> 131 </td>
   <td style="text-align:left;"> Model </td>
   <td style="text-align:left;"> 97 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Machine </td>
   <td style="text-align:left;"> 105 </td>
   <td style="text-align:left;"> Prediction </td>
   <td style="text-align:left;"> 80 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Deep Learning </td>
   <td style="text-align:left;"> 97 </td>
   <td style="text-align:left;"> Algorithm </td>
   <td style="text-align:left;"> 78 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Classification </td>
   <td style="text-align:left;"> 96 </td>
   <td style="text-align:left;"> Neural-Networks </td>
   <td style="text-align:left;"> 70 </td>
  </tr>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>2021</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Machine Learning </td>
   <td style="text-align:left;"> 80 </td>
   <td style="text-align:left;"> Classification </td>
   <td style="text-align:left;"> 8 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Optimization </td>
   <td style="text-align:left;"> 17 </td>
   <td style="text-align:left;"> Model </td>
   <td style="text-align:left;"> 5 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Deep Learning </td>
   <td style="text-align:left;"> 15 </td>
   <td style="text-align:left;"> Performance </td>
   <td style="text-align:left;"> 5 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Artificial Intelligence </td>
   <td style="text-align:left;"> 10 </td>
   <td style="text-align:left;"> Prediction </td>
   <td style="text-align:left;"> 5 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Computational Modeling </td>
   <td style="text-align:left;"> 10 </td>
   <td style="text-align:left;"> Uncertainty </td>
   <td style="text-align:left;"> 4 </td>
  </tr>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>2020</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Machine Learning </td>
   <td style="text-align:left;"> 210 </td>
   <td style="text-align:left;"> Model </td>
   <td style="text-align:left;"> 31 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Learning </td>
   <td style="text-align:left;"> 43 </td>
   <td style="text-align:left;"> Classification </td>
   <td style="text-align:left;"> 26 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Deep Learning </td>
   <td style="text-align:left;"> 40 </td>
   <td style="text-align:left;"> Algorithm </td>
   <td style="text-align:left;"> 19 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Machine </td>
   <td style="text-align:left;"> 34 </td>
   <td style="text-align:left;"> Neural-Networks </td>
   <td style="text-align:left;"> 16 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Optimization </td>
   <td style="text-align:left;"> 24 </td>
   <td style="text-align:left;"> Optimization </td>
   <td style="text-align:left;"> 16 </td>
  </tr>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>2019</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Machine Learning </td>
   <td style="text-align:left;"> 188 </td>
   <td style="text-align:left;"> Model </td>
   <td style="text-align:left;"> 25 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Learning </td>
   <td style="text-align:left;"> 28 </td>
   <td style="text-align:left;"> Classification </td>
   <td style="text-align:left;"> 18 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Machine </td>
   <td style="text-align:left;"> 24 </td>
   <td style="text-align:left;"> Models </td>
   <td style="text-align:left;"> 18 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Deep Learning </td>
   <td style="text-align:left;"> 18 </td>
   <td style="text-align:left;"> Prediction </td>
   <td style="text-align:left;"> 18 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Artificial Intelligence </td>
   <td style="text-align:left;"> 13 </td>
   <td style="text-align:left;"> Neural-Networks </td>
   <td style="text-align:left;"> 16 </td>
  </tr>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>2018</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Machine Learning </td>
   <td style="text-align:left;"> 99 </td>
   <td style="text-align:left;"> Classification </td>
   <td style="text-align:left;"> 18 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Machine </td>
   <td style="text-align:left;"> 15 </td>
   <td style="text-align:left;"> Algorithm </td>
   <td style="text-align:left;"> 13 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Deep Learning </td>
   <td style="text-align:left;"> 14 </td>
   <td style="text-align:left;"> Prediction </td>
   <td style="text-align:left;"> 12 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Classification </td>
   <td style="text-align:left;"> 13 </td>
   <td style="text-align:left;"> Regression </td>
   <td style="text-align:left;"> 9 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Learning </td>
   <td style="text-align:left;"> 12 </td>
   <td style="text-align:left;"> Selection </td>
   <td style="text-align:left;"> 9 </td>
  </tr>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>2017</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Machine Learning </td>
   <td style="text-align:left;"> 74 </td>
   <td style="text-align:left;"> Selection </td>
   <td style="text-align:left;"> 14 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Learning </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> Classification </td>
   <td style="text-align:left;"> 13 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Neural Networks </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> Neural-Networks </td>
   <td style="text-align:left;"> 12 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Privacy </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> Models </td>
   <td style="text-align:left;"> 9 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Deep Learning </td>
   <td style="text-align:left;"> 7 </td>
   <td style="text-align:left;"> Optimization </td>
   <td style="text-align:left;"> 8 </td>
  </tr>
</tbody>
</table></div>

]

<div class="figure" style="text-align: center">
<img src="./figures/figure2.png" alt="Author's Keywords Usage Evolution Over Time" width="60%" />
<p class="caption">Author's Keywords Usage Evolution Over Time</p>
</div>

]

---
class: center, middle

# Keywords' co-occurrences

---

### Keyword co-occurrences networks

- Co-word networks show the conceptual structure, that uncovers links between concepts through term co-occurences.

- Conceptual structure is often used to understand the topics covered by scholars (so-called research front) and identify what are the most important and the most recent issues.

- Dividing the whole timespan in different timeslices and comparing the conceptual structures is useful to analyze the evolution of topics over time.

---

<div class="figure" style="text-align: center">
<img src="./figures/figure3.png" alt="Network of authors' keywords, overall period, and per year" width="60%" />
<p class="caption">Network of authors' keywords, overall period, and per year</p>
</div>

]

]

]

]

]

]

<table class=" lightable-classic" style='font-family: "Arial Narrow", "Source Sans Pro", sans-serif; margin-left: auto; margin-right: auto;'>
<caption>Graph indicators, overall period, and per year</caption>
 <thead>
  <tr>
   <th style="text-align:left;"> Statistics </th>
   <th style="text-align:right;"> Overall Time Period </th>
   <th style="text-align:right;"> 2021 </th>
   <th style="text-align:right;"> 2020 </th>
   <th style="text-align:right;"> 2019 </th>
   <th style="text-align:right;"> 2018 </th>
   <th style="text-align:right;"> 2017 </th>
  </tr>
 </thead>
<tbody>
  <tr>
   <td style="text-align:left;"> Size </td>
   <td style="text-align:right;"> 3606.000 </td>
   <td style="text-align:right;"> 234.000 </td>
   <td style="text-align:right;"> 946.000 </td>
   <td style="text-align:right;"> 849.000 </td>
   <td style="text-align:right;"> 693.000 </td>
   <td style="text-align:right;"> 604.000 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Density </td>
   <td style="text-align:right;"> 0.005 </td>
   <td style="text-align:right;"> 0.036 </td>
   <td style="text-align:right;"> 0.014 </td>
   <td style="text-align:right;"> 0.016 </td>
   <td style="text-align:right;"> 0.018 </td>
   <td style="text-align:right;"> 0.021 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Transitivity </td>
   <td style="text-align:right;"> 0.128 </td>
   <td style="text-align:right;"> 0.538 </td>
   <td style="text-align:right;"> 0.238 </td>
   <td style="text-align:right;"> 0.232 </td>
   <td style="text-align:right;"> 0.266 </td>
   <td style="text-align:right;"> 0.269 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Diameter </td>
   <td style="text-align:right;"> 6.000 </td>
   <td style="text-align:right;"> 6.000 </td>
   <td style="text-align:right;"> 6.000 </td>
   <td style="text-align:right;"> 6.000 </td>
   <td style="text-align:right;"> 6.000 </td>
   <td style="text-align:right;"> 6.000 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Degree Centralization </td>
   <td style="text-align:right;"> 0.298 </td>
   <td style="text-align:right;"> 0.188 </td>
   <td style="text-align:right;"> 0.230 </td>
   <td style="text-align:right;"> 0.303 </td>
   <td style="text-align:right;"> 0.317 </td>
   <td style="text-align:right;"> 0.333 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Average path length </td>
   <td style="text-align:right;"> 2.753 </td>
   <td style="text-align:right;"> 3.067 </td>
   <td style="text-align:right;"> 2.792 </td>
   <td style="text-align:right;"> 2.716 </td>
   <td style="text-align:right;"> 2.732 </td>
   <td style="text-align:right;"> 2.682 </td>
  </tr>
</tbody>
</table>

]

---
class: middle, center

# Topic modelling

---

<div class="figure" style="text-align: center">
<img src="./figures/figure4.png" alt="Topic modeling, overall period, and per year" width="60%" />
<p class="caption">Topic modeling, overall period, and per year</p>
</div>

]

]

]

]

]

]

---

# Synthesis: authors, keywords, journals

---

<div class="figure" style="text-align: center">
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<p class="caption">Three fields plot, overall period and per year</p>
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]

---

# 4. Social Structures

---
class: center, middle

# Authors' collaboration networks

---

<div class="figure" style="text-align: center">
<img src="./figures/figure10.png" alt="Authors' collaboration networks, overall period, and per year" width="60%" />
<p class="caption">Authors' collaboration networks, overall period, and per year</p>
</div>

]

]

<img src="./figures/2018_figure6.png" width="60%" style="display: block; margin: auto;" />
]

]

]

]

---
class: center, middle

# Journals' (Source) co-citation analyses

---

<div class="figure" style="text-align: center">
<img src="./figures/figure14.png" alt="Journals source co-citation analysis, overall period, and per year" width="60%" />
<p class="caption">Journals source co-citation analysis, overall period, and per year</p>
</div>

]

]

]

]

]

]

---
class: center, middle

# Universities' collaboration networks

---

<div class="figure" style="text-align: center">
<img src="./figures/figure15.png" alt="University collaboration networks, overall period, and per year." width="60%" />
<p class="caption">University collaboration networks, overall period, and per year.</p>
</div>

]

]

]

]

]

]

---
class: center, middle

# Countries' collaborations

---

<div style="border: 1px solid #ddd; padding: 0px; overflow-y: scroll; height:400px; overflow-x: scroll; width:100%; "><table class=" lightable-classic" style='font-family: "Arial Narrow", "Source Sans Pro", sans-serif; margin-left: auto; margin-right: auto;'>
<caption>Corresponding author's countries, overall period and per year</caption>
 <thead>
  <tr>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> Country </th>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> Articles </th>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> Freq </th>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> SCP </th>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> MCP </th>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> MCP_Ratio </th>
  </tr>
 </thead>
<tbody>
  <tr grouplength="5"><td colspan="6" style="border-bottom: 0;"><strong>Overall Time Period</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United States </td>
   <td style="text-align:left;"> 784 </td>
   <td style="text-align:left;"> 0.3078 </td>
   <td style="text-align:left;"> 644 </td>
   <td style="text-align:left;"> 140 </td>
   <td style="text-align:left;"> 0.179 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> China </td>
   <td style="text-align:left;"> 291 </td>
   <td style="text-align:left;"> 0.1143 </td>
   <td style="text-align:left;"> 207 </td>
   <td style="text-align:left;"> 84 </td>
   <td style="text-align:left;"> 0.289 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United Kingdom </td>
   <td style="text-align:left;"> 137 </td>
   <td style="text-align:left;"> 0.0538 </td>
   <td style="text-align:left;"> 91 </td>
   <td style="text-align:left;"> 46 </td>
   <td style="text-align:left;"> 0.336 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Germany </td>
   <td style="text-align:left;"> 109 </td>
   <td style="text-align:left;"> 0.0428 </td>
   <td style="text-align:left;"> 77 </td>
   <td style="text-align:left;"> 32 </td>
   <td style="text-align:left;"> 0.294 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> India </td>
   <td style="text-align:left;"> 107 </td>
   <td style="text-align:left;"> 0.0420 </td>
   <td style="text-align:left;"> 94 </td>
   <td style="text-align:left;"> 13 </td>
   <td style="text-align:left;"> 0.121 </td>
  </tr>
  <tr grouplength="5"><td colspan="6" style="border-bottom: 0;"><strong>2021</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United States </td>
   <td style="text-align:left;"> 47 </td>
   <td style="text-align:left;"> 0.2597 </td>
   <td style="text-align:left;"> 39 </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> 0.170 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> China </td>
   <td style="text-align:left;"> 26 </td>
   <td style="text-align:left;"> 0.1436 </td>
   <td style="text-align:left;"> 16 </td>
   <td style="text-align:left;"> 10 </td>
   <td style="text-align:left;"> 0.385 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> India </td>
   <td style="text-align:left;"> 17 </td>
   <td style="text-align:left;"> 0.0939 </td>
   <td style="text-align:left;"> 14 </td>
   <td style="text-align:left;"> 3 </td>
   <td style="text-align:left;"> 0.176 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United Kingdom </td>
   <td style="text-align:left;"> 10 </td>
   <td style="text-align:left;"> 0.0552 </td>
   <td style="text-align:left;"> 5 </td>
   <td style="text-align:left;"> 5 </td>
   <td style="text-align:left;"> 0.500 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Canada </td>
   <td style="text-align:left;"> 9 </td>
   <td style="text-align:left;"> 0.0497 </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0.111 </td>
  </tr>
  <tr grouplength="5"><td colspan="6" style="border-bottom: 0;"><strong>2020</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United States </td>
   <td style="text-align:left;"> 144 </td>
   <td style="text-align:left;"> 0.2722 </td>
   <td style="text-align:left;"> 119 </td>
   <td style="text-align:left;"> 25 </td>
   <td style="text-align:left;"> 0.174 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> China </td>
   <td style="text-align:left;"> 70 </td>
   <td style="text-align:left;"> 0.1323 </td>
   <td style="text-align:left;"> 49 </td>
   <td style="text-align:left;"> 21 </td>
   <td style="text-align:left;"> 0.300 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Germany </td>
   <td style="text-align:left;"> 28 </td>
   <td style="text-align:left;"> 0.0529 </td>
   <td style="text-align:left;"> 20 </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> 0.286 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Korea </td>
   <td style="text-align:left;"> 28 </td>
   <td style="text-align:left;"> 0.0529 </td>
   <td style="text-align:left;"> 20 </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> 0.286 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United Kingdom </td>
   <td style="text-align:left;"> 26 </td>
   <td style="text-align:left;"> 0.0491 </td>
   <td style="text-align:left;"> 15 </td>
   <td style="text-align:left;"> 11 </td>
   <td style="text-align:left;"> 0.423 </td>
  </tr>
  <tr grouplength="5"><td colspan="6" style="border-bottom: 0;"><strong>2019</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United States </td>
   <td style="text-align:left;"> 162 </td>
   <td style="text-align:left;"> 0.3202 </td>
   <td style="text-align:left;"> 126 </td>
   <td style="text-align:left;"> 36 </td>
   <td style="text-align:left;"> 0.2222 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> China </td>
   <td style="text-align:left;"> 74 </td>
   <td style="text-align:left;"> 0.1462 </td>
   <td style="text-align:left;"> 46 </td>
   <td style="text-align:left;"> 28 </td>
   <td style="text-align:left;"> 0.3784 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United Kingdom </td>
   <td style="text-align:left;"> 23 </td>
   <td style="text-align:left;"> 0.0455 </td>
   <td style="text-align:left;"> 15 </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> 0.3478 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Germany </td>
   <td style="text-align:left;"> 21 </td>
   <td style="text-align:left;"> 0.0415 </td>
   <td style="text-align:left;"> 16 </td>
   <td style="text-align:left;"> 5 </td>
   <td style="text-align:left;"> 0.2381 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> France </td>
   <td style="text-align:left;"> 20 </td>
   <td style="text-align:left;"> 0.0395 </td>
   <td style="text-align:left;"> 13 </td>
   <td style="text-align:left;"> 7 </td>
   <td style="text-align:left;"> 0.3500 </td>
  </tr>
  <tr grouplength="5"><td colspan="6" style="border-bottom: 0;"><strong>2018</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United States </td>
   <td style="text-align:left;"> 107 </td>
   <td style="text-align:left;"> 0.3344 </td>
   <td style="text-align:left;"> 85 </td>
   <td style="text-align:left;"> 22 </td>
   <td style="text-align:left;"> 0.2056 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> China </td>
   <td style="text-align:left;"> 35 </td>
   <td style="text-align:left;"> 0.1094 </td>
   <td style="text-align:left;"> 26 </td>
   <td style="text-align:left;"> 9 </td>
   <td style="text-align:left;"> 0.2571 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United Kingdom </td>
   <td style="text-align:left;"> 23 </td>
   <td style="text-align:left;"> 0.0719 </td>
   <td style="text-align:left;"> 16 </td>
   <td style="text-align:left;"> 7 </td>
   <td style="text-align:left;"> 0.3043 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> India </td>
   <td style="text-align:left;"> 12 </td>
   <td style="text-align:left;"> 0.0375 </td>
   <td style="text-align:left;"> 11 </td>
   <td style="text-align:left;"> 1 </td>
   <td style="text-align:left;"> 0.0833 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Italy </td>
   <td style="text-align:left;"> 12 </td>
   <td style="text-align:left;"> 0.0375 </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> 4 </td>
   <td style="text-align:left;"> 0.3333 </td>
  </tr>
  <tr grouplength="5"><td colspan="6" style="border-bottom: 0;"><strong>2017</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United States </td>
   <td style="text-align:left;"> 75 </td>
   <td style="text-align:left;"> 0.3138 </td>
   <td style="text-align:left;"> 65 </td>
   <td style="text-align:left;"> 10 </td>
   <td style="text-align:left;"> 0.133 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> China </td>
   <td style="text-align:left;"> 17 </td>
   <td style="text-align:left;"> 0.0711 </td>
   <td style="text-align:left;"> 12 </td>
   <td style="text-align:left;"> 5 </td>
   <td style="text-align:left;"> 0.294 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> United Kingdom </td>
   <td style="text-align:left;"> 15 </td>
   <td style="text-align:left;"> 0.0628 </td>
   <td style="text-align:left;"> 10 </td>
   <td style="text-align:left;"> 5 </td>
   <td style="text-align:left;"> 0.333 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> India </td>
   <td style="text-align:left;"> 13 </td>
   <td style="text-align:left;"> 0.0544 </td>
   <td style="text-align:left;"> 11 </td>
   <td style="text-align:left;"> 2 </td>
   <td style="text-align:left;"> 0.154 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Germany </td>
   <td style="text-align:left;"> 12 </td>
   <td style="text-align:left;"> 0.0502 </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> 4 </td>
   <td style="text-align:left;"> 0.333 </td>
  </tr>
</tbody>
</table></div>

]

]

---

<div class="figure" style="text-align: center">
<img src="./figures/figure12.png" alt="The most productive countries (according to authors' residence)" width="50%" />
<p class="caption">The most productive countries (according to authors' residence)</p>
</div>

]

]

---
class: center, middle

# Countries' collaboration networks

---

<div class="figure" style="text-align: center">
<img src="./figures/figure13.png" alt="Country collaboration networks, overall period, and per year" width="60%" />
<p class="caption">Country collaboration networks, overall period, and per year</p>
</div>
]

]

]

]

<img src="./figures/2020_figure13.png" width="60%" style="display: block; margin: auto;" />
]

]

---

# 8. Conclusion

---

### 8. Conclusion

- Metadata systematic review: What is it?

- Why can it be useful?

- Next steps?

---

# Appendix 1. Intellectual Structures

---

### Articles citations

Citation analysis is one of the main classic techniques in bibliometrics.

It shows the structure of a specific field through the linkages between nodes (e.g. authors, papers, journal), while the edges can be differently interpreted depending on the network type, that are namely co-citation, direct citation, bibliographic coupling.

---

### Articles

<div style="border: 1px solid #ddd; padding: 0px; overflow-y: scroll; height:400px; overflow-x: scroll; width:100%; "><table class=" lightable-classic" style='font-family: "Arial Narrow", "Source Sans Pro", sans-serif; margin-left: auto; margin-right: auto;'>
<caption>Most Cited Manuscripts</caption>
 <thead>
  <tr>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> Article </th>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> Total citations </th>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> Total citations per year </th>
   <th style="text-align:left;position: sticky; top:0; background-color: #FFFFFF;"> NTC </th>
  </tr>
 </thead>
<tbody>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>Overall Time Period</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Bottou L, 2010, Compstat'2010: 19th International Conference On Computational Statistics </td>
   <td style="text-align:left;"> 1774 </td>
   <td style="text-align:left;"> 147.8 </td>
   <td style="text-align:left;"> 23.70 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Blankertz B, 2008, Ieee Signal Process Mag </td>
   <td style="text-align:left;"> 1115 </td>
   <td style="text-align:left;"> 79.6 </td>
   <td style="text-align:left;"> 23.72 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Holte Rc, 1993, Mach Learn </td>
   <td style="text-align:left;"> 966 </td>
   <td style="text-align:left;"> 33.3 </td>
   <td style="text-align:left;"> 1.00 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Cawley Gc, 2010, J Mach Learn Res </td>
   <td style="text-align:left;"> 700 </td>
   <td style="text-align:left;"> 58.3 </td>
   <td style="text-align:left;"> 9.35 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Wellendorff J, 2012, Phys Rev B </td>
   <td style="text-align:left;"> 681 </td>
   <td style="text-align:left;"> 68.1 </td>
   <td style="text-align:left;"> 14.10 </td>
  </tr>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>2017</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Sze V, 2017, Proc Ieee </td>
   <td style="text-align:left;"> 643 </td>
   <td style="text-align:left;"> 128.6 </td>
   <td style="text-align:left;"> 49.18 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Kraus M, 2017, Decis Support Syst </td>
   <td style="text-align:left;"> 73 </td>
   <td style="text-align:left;"> 14.6 </td>
   <td style="text-align:left;"> 5.58 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Raman Mrg, 2017, Knowledge-Based Syst </td>
   <td style="text-align:left;"> 69 </td>
   <td style="text-align:left;"> 13.8 </td>
   <td style="text-align:left;"> 5.28 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Ratner A, 2017, Proc Vldb Endow </td>
   <td style="text-align:left;"> 68 </td>
   <td style="text-align:left;"> 13.6 </td>
   <td style="text-align:left;"> 5.20 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Schuler Ms, 2017, Am J Epidemiol </td>
   <td style="text-align:left;"> 68 </td>
   <td style="text-align:left;"> 13.6 </td>
   <td style="text-align:left;"> 5.20 </td>
  </tr>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>2018</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Lee K, 2018, Ieee Trans Inf Theory </td>
   <td style="text-align:left;"> 158 </td>
   <td style="text-align:left;"> 39.5 </td>
   <td style="text-align:left;"> 18.53 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Coley Cw, 2018, Accounts Chem Res </td>
   <td style="text-align:left;"> 149 </td>
   <td style="text-align:left;"> 37.2 </td>
   <td style="text-align:left;"> 17.47 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Yuan R, 2018, Adv Mater </td>
   <td style="text-align:left;"> 93 </td>
   <td style="text-align:left;"> 23.2 </td>
   <td style="text-align:left;"> 10.91 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Chen Py, 2018, Ieee Trans Comput-Aided Des Integr Circuits Syst </td>
   <td style="text-align:left;"> 83 </td>
   <td style="text-align:left;"> 20.8 </td>
   <td style="text-align:left;"> 9.73 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Yu Jjq, 2018, Ieee Trans Power Syst </td>
   <td style="text-align:left;"> 80 </td>
   <td style="text-align:left;"> 20.0 </td>
   <td style="text-align:left;"> 9.38 </td>
  </tr>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>2019</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Mozaffari M, 2019, Ieee Commun Surv Tutor </td>
   <td style="text-align:left;"> 277 </td>
   <td style="text-align:left;"> 92.3 </td>
   <td style="text-align:left;"> 42.86 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Wang S, 2019, Ieee J Sel Areas Commun </td>
   <td style="text-align:left;"> 130 </td>
   <td style="text-align:left;"> 43.3 </td>
   <td style="text-align:left;"> 20.12 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Mehta P, 2019, Phys Rep -Rev Sec Phys Lett </td>
   <td style="text-align:left;"> 128 </td>
   <td style="text-align:left;"> 42.7 </td>
   <td style="text-align:left;"> 19.81 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Sangaiah Ak, 2019, Ieee Trans Ind Inform </td>
   <td style="text-align:left;"> 79 </td>
   <td style="text-align:left;"> 26.3 </td>
   <td style="text-align:left;"> 12.22 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Park J, 2019, Proc Ieee </td>
   <td style="text-align:left;"> 69 </td>
   <td style="text-align:left;"> 23.0 </td>
   <td style="text-align:left;"> 10.68 </td>
  </tr>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>2020</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Zuo Y, 2020, J Phys Chem A </td>
   <td style="text-align:left;"> 67 </td>
   <td style="text-align:left;"> 33.5 </td>
   <td style="text-align:left;"> 27.93 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Yang Hh, 2020, Ieee Trans Commun </td>
   <td style="text-align:left;"> 37 </td>
   <td style="text-align:left;"> 18.5 </td>
   <td style="text-align:left;"> 15.42 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Zhu G, 2020, Ieee Trans Wirel Commun </td>
   <td style="text-align:left;"> 36 </td>
   <td style="text-align:left;"> 18.0 </td>
   <td style="text-align:left;"> 15.00 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Foscato M, 2020, Acs Catal </td>
   <td style="text-align:left;"> 26 </td>
   <td style="text-align:left;"> 13.0 </td>
   <td style="text-align:left;"> 10.84 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Ravishankar S, 2020, Proc Ieee </td>
   <td style="text-align:left;"> 25 </td>
   <td style="text-align:left;"> 12.5 </td>
   <td style="text-align:left;"> 10.42 </td>
  </tr>
  <tr grouplength="5"><td colspan="4" style="border-bottom: 0;"><strong>2021</strong></td></tr>
<tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Wang C, 2021, Ieee Trans Serv Comput </td>
   <td style="text-align:left;"> 63 </td>
   <td style="text-align:left;"> 63 </td>
   <td style="text-align:left;"> 62.32 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Berk R, 2021, Sociol Methods Res </td>
   <td style="text-align:left;"> 44 </td>
   <td style="text-align:left;"> 44 </td>
   <td style="text-align:left;"> 43.52 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Folmsbee D, 2021, Int J Quantum Chem </td>
   <td style="text-align:left;"> 10 </td>
   <td style="text-align:left;"> 10 </td>
   <td style="text-align:left;"> 9.89 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Hassija V, 2021, Ieee Internet Things J </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> 8 </td>
   <td style="text-align:left;"> 7.91 </td>
  </tr>
  <tr>
   <td style="text-align:left;padding-left: 2em;" indentlevel="1"> Carta S, 2021, Appl Intell </td>
   <td style="text-align:left;"> 7 </td>
   <td style="text-align:left;"> 7 </td>
   <td style="text-align:left;"> 6.92 </td>
  </tr>
</tbody>
</table></div>

]
.panel[.panel-name[Overall time period]

<div class="figure" style="text-align: center">
<img src="./figures/figure9.png" alt="Most cited manuscripts, overall period, and per year" width="50%" />
<p class="caption">Most cited manuscripts, overall period, and per year</p>
</div>

]

]

]

---

### Co-Citation of Articles Network

<div class="figure" style="text-align: center">
<img src="./figures/figure11.png" alt="Co-citations of articles, overall period, and per year" width="50%" />
<p class="caption">Co-citations of articles, overall period, and per year</p>
</div>

]

]

]

]

]

]

---

### Top Authors

<div class="figure" style="text-align: center">
<img src="./figures/figure5.png" alt="Top authors in terms of production, overall period, and per year" width="50%" />
<p class="caption">Top authors in terms of production, overall period, and per year</p>
</div>

]

]

---

### Scientific Productivity

<div class="figure" style="text-align: center">
<img src="./figures/scientific_productivity.png" alt="Scientific productivity, overall period, and per year" width="60%" />
<p class="caption">Scientific productivity, overall period, and per year</p>
</div>

]

]

]

]

]

]

---

### Most Cited Authors

<div class="figure" style="text-align: center">
<img src="./figures/figure8.png" alt=" Analysis of cited references, overall period, and per year" width="50%" />
<p class="caption"> Analysis of cited references, overall period, and per year</p>
</div>
]

]

---

### Authors Dominance Ranking

<div class="figure" style="text-align: center">
<img src="./figures/figure7.png" alt="Author dominance ranking, overall period, and per year" width="40%" />
<p class="caption">Author dominance ranking, overall period, and per year</p>
</div>

]

]

---

### Journals

---

# References

---

### References

- Kouloukoui D., de Marcellis-Warin N., Armellini F., Warin Th. and Andrade Torres E. (2021) “Factors influencing the perception of exposure to climate risks: evidence from the world’s largest carbon-intensive industries” Journal of Cleaner Production https://doi.org/10.1016/j.jclepro.2021.127160

- Vorreuther C. M. and Warin Th. (2021) “Patent Relatedness and Velocity in the Chinese Pharmaceutical Industry: A Dataset of Jaccard Similarity Indices” (with Vorreuther, C.), Data in Brief, Volume 35 https://doi.org/10.1016/j.d

- Warin Th. (2020) “Global Research on Coronaviruses: An R Package”, J Med Internet Res, Vol. 22, No. 8, August, 2020 [DOI:10.2196/19615]

- Warin Th. and Sanger W. (2018) “Connectivity and Closeness Among International Financial Institutions: A Network Theory Perspective”, International Journal of Comparative Management, lead article, vol. 1, no. 3, pp. 225-254 [DOI: 10.1504/IJCM.2018.10015714] [PDF] Highly Commended Paper Award (2017-2018)

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### References

- Sanger W. and Warin Th. (2018) “Public’s Perception of Political Parties during the 2014 Quebec Election on Twitter” Canadian Journal of Communication, volume 43.2, [DOI: 10.22230/cjc.2018v43n2a3251]

- Sanger W. and Warin Th. (2017) “The 2015 Canadian Election on Twitter: A Tidy Algorithmic Analysis” Proceedings of the 2017 International Conference on Computational Science and Computational Intelligence (CSCI’17: 14-16 December, Las Vegas, Nevada, USA); Included in IEEE Xplore; Publisher: IEEE Computer Society, Editors: H. R. Arabnia, L. Deligiannidis, F. G. Tinetti, Q-N. Tran, M. Qu Yang; ISBN-13: 978-1-5386-2652-8; BMS Part # CFP1771X-USB; [DOI: 10.1109/CSCI.2017.158]; paper acceptance rate: 21%; 2017

- Le Duc R., Sanger W. and Warin Th. (2017) “Mapping Innovations in Artificial Intelligence Through Patents: A Social Data Science Perspective”, Proceedings of the 2017 International Conference on Computational Science and Computational Intelligence (CSCI’17: 14-16 December, Las Vegas, Nevada, USA); Included in IEEE Xplore; Publisher: IEEE Computer Society, Editors: H. R. Arabnia, L. Deligiannidis, F. G. Tinetti, Q-N. Tran, M. Qu Yang; ISBN-13: 978-1-5386-2652-8; BMS Part # CFP1771X-USB; [DOI 10.1109/CSCI.2017.40]; paper acceptance rate: 21%; 2017

- de Marcellis-Warin N., Sanger W. and Warin Th. (2017) “A Network Analysis of Financial Conversations on Twitter” International Journal of Web Based Communities, Volume 13, Issue 3, pp. 286-310 [DOI: 10.1504/IJWBC.2017.10004118]