# Information and Communication Technology Solutions for the Circular Economy
## 2 Information and Communication Technology Solutions for the Circular Economy
### Categorization Method
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**General** **Categorization**} & \multirow{2}{*}{**Subcategorization**} & \multirow{2}{*}{**Specific Technology**} & \multicolumn{5}{c}{**Circular Economy Concepts**} \\ \cline{3-6}  & & & **Reduce** & **Reuse** & **Resycle/** & **All Four** \\  & & & & & **Resstore** & **Concepts** \\ \hline \multirow{9}{*}{**Data Collection**} & \multirow{9}{*}{**Other Data Analytics**} & Neural Networks & [46] & & & \\  & & Support Vector Machines & & & & [50] \\  & & & & [22] & & [65] \\  & & Recommender Systems & & [53] & & \\  & & Semantic Processing & & [56, 58] & & \\  & & Ontology Engineering & [56, 58] & & & \\  & & Semantic Modelling & [58] & & & \\ \hline \multirow{9}{*}{**Data Management**} & \multirow{9}{*}{**Non-Modern Management**} & [60] & [64] & [62] & & \\  & & BIM & [46] & [64] & [65] & \\  & & IoT & [22, 27, 32, 85, 1] & [68] & [37, 62] & \\  & & IoT & [13, 70] & & & \\  & & IoMT & [81] & & & \\  & & Satellite Imaging and GIS & & [45, 72, 73] & & & \\  & & SCADA & & [11, 49, 75] & & \\  & & Wireless Sensor Networks & [76, 77] & & & \\ \hline \multirow{9}{*}{**Data Management**} & \multirow{9}{*}{**Non-Modern Management**} & Blockchain & [18, 27, 84, 86] & [55] & [85] & \\  & & Data Privacy/Security & & [81] & & \\  & & Information Management Systems & & [62, 79] & & \\  & & Systems & & [80] & & \\  & & & RDBMS & & [80] & \\  & & Smart Contracts & [86] & & & \\ \hline \multirow{9}{*}{**Software and**} & Digital Patterns & [49, 75, 76, 77] & [87] & & [88] \\  & & PLM Systems & [72] & [87] & & \\ \cline{1-1} Simulation & Simulation Technologies & [11, 35, 89] & & & [90] \\ \cline{1-1}  & & Smartphone Applications & [92] & & [91] \\ \cline{1-1}  & & Software Tools & [41, 42, 65, 93, 94, 95] & & & \\ \hline \multirow{2}{*}{**Other Smart**} & Smart Grids & [18] & & & & \\ \cline{1-1}  & & Smart Products & [32, 67] & [68] & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._For the general technological categorization of the solutions, the seven categories identified and mentioned in the beginning of Section 2 were utilized, complemented by an eighth category containing other smart solutions which could not be categorized into any of our seven main categories. To make the results clearer and more usable, the general technological categorization was followed by a subcategorization. 46 subcategories were utilized for our purposes. In seven subcategories, a subsequent third subcategorization was used to indicate the specific solutions presented. Several solutions utilizing different technologies can be found in different technological categories and subcategories. Regarding the relevance to the 4R concepts, we used 4 categories: (1) Reduce, (2) Reuse, (3) Recycle/Recover, and (4) Relevance to all four concepts. \"recycle\" and \"recover\" concepts were presented in the same column, as only a few solutions were relevant to the \"recover\" concept alone. Thus, we managed to keep the table less complicated. Lastly, for the CE concept categorization, each solution was categorized into only one of the four categories (the most relevant one).