# An Adapted Model of Cognitive Digital Twins for Building Lifecycle Management
## 2 Theoretical Background
### Digital Twins (DTs) in the Built Environment  
The CPS is realized through the DT for visualization, modeling, simulation, analysis, prediction, and optimization. DT contains three main components to create a practical loop: a physical entity, a virtual entity, and a data link [18]. Usually, there are two approaches to dynamic mapping in the DT. Inspection data are gathered in the physical world and subsequently transmitted to the virtual world for further analysis. Simulation, prediction, and optimization are achieved in the virtual model by learning data from multiple sources, offering prompt solutions to guide the realistic process and adapt to the changing context.  
Based on [PERSON] and [PERSON] [19], DTs have various features in the AEC industry such as Real-time (gather and present real-time data of physical assets), Analytics (store data, run continuous analytics from historical data, and provide helpful insight). Simulations (utilize to run various data-driven simulations), visualization (overlay real-life and live 3D BIM models, images, and videos of the physical asset and also the foundation for immersive visualizations), Automation (a bi-directional system that can manage the behavior of physical assets), and Predictions (provide predictions of assets' future behaviors using historical data and analytics of various scenarios assets). As a comprehensive summary, Table 1 presents DT applications in the AEC industry that appeared in the recent literature (2019-2021).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \(n\) & **Author(s)** & **References** & **Year** & **Applications** \\ \hline \multirow{2}{*}{1} & [PERSON] and & \multirow{2}{*}{[19]} & \multirow{2}{*}{2021} & Developed and evaluated a DT-based construction & \\  & Yitmen & & & progress monitoring system called DRX. & \\ \hline \multirow{2}{*}{2} & [PERSON] et al. & \multirow{2}{*}{[20]} & \multirow{2}{*}{2021} & The transition from BIM to DTs in built-environment & \\  & & & applications was studied. & \\ \hline \multirow{2}{*}{3} & [PERSON] and [PERSON] & \multirow{2}{*}{[18]} & \multirow{2}{*}{2021} & A data-driven DT architecture based on data mining, & \\  & & & BIM, and IoT was developed for comprehensive project & management. & \\ \hline \multirow{2}{*}{4} & [PERSON] et al. & \multirow{2}{*}{[21]} & \multirow{2}{*}{2021} & Examined the digital Technology applications in the AEC industry. & \\ \hline \multirow{2}{*}{5} & [PERSON] et al. & \multirow{2}{*}{[22]} & \multirow{2}{*}{2021} & Investigated construction machinery operation and work & \\  & & & tracking through AR and DT. & \\ \hline \multirow{2}{*}{6} & [PERSON] et al. & \multirow{2}{*}{[23]} & \multirow{2}{*}{2021} & Examined how AEC/FM professionals describe built \\  & & & asset DTs. & \\ \hline \multirow{2}{*}{7} & [PERSON] et al. & \multirow{2}{*}{[24]} & \multirow{2}{*}{2021} & Devoted BIM-based DT for road constructed using \\  & & & secondary raw materials (SRMs) & \\ \hline \multirow{2}{*}{8} & [PERSON] et al. & \multirow{2}{*}{[25]} & \multirow{2}{*}{2021} & Reviewed the applications and challenges of DTs in \\  & & & construction safety. & \\ \hline \multirow{2}{*}{9} & [PERSON] & \multirow{2}{*}{[26]} & \multirow{2}{*}{2021} & Reviewed the contemporary actions utilized and \\  & & & challenged in the energy sector through the enterprises. \\ \hline \multirow{2}{*}{10} & [PERSON] and & \multirow{2}{*}{[27]} & \multirow{2}{*}{2021} & Investigated DT-based approaches, tools, and \\  & Osello & & implementations that can be adapted for achieving smart \\ \hline \hline \end{tabular}
\end{table}
Table 1: Digital Twins applications in the AEC industry that appeared in the recent literature.