# Robust Simulation of Cyber-Physical Systems for Environmental Monitoring on Construction Sites
## 2 Literature Review  
### Applicability of CPS  
According to the previously mentioned characteristics, CPS can enhance the information processing and address human-machine-environment coupling problems by achieving bidirectional coordination between the virtual world and physical structures [9]. Hence, CPS are used in several fields, including manufacturing, transportation, and the construction industry. When CPS are used on construction sites during the construction process, their data are first collected by the sensors on construction sites. Consequently, the decision support system (DSS) makes decisions, and the actuator network then takes necessary actions in response to the dynamic environmental changes on construction sites and maintains interaction with project managers. Therefore, some researchers endeavor to conduct the building monitoring and visualization of construction sites using CPS. For instance, [PERSON] et al. proposed temporary-structure monitoring (TSM) based on CPS. The latter integrates the virtual model and physical structure on construction sites [22]. [PERSON] et al. created a cyber-physical postural training environment using wearable sensors [23]. During the operation period of projects, CPS can also be used to monitor the real-time performance of buildings, in order to offer insurance for project managers in decision-making. This can be achieved by combining building information-modeling (BIM) and CPS, after they are tested by a customized simulator [24]. As for E-CPS, important studies try to combine the environmental monitoring with CPS in order to handle environmental issues, and the system architecture of the E-CPS has been developed and enriched (cf. Table 1).  
In summary, previous studies have confirmed the applicability of CPS in the construction and operation period; it plays a crucial role in the management of the building life-cycle. Although significant efforts have been made toward CPS-based environmental monitoring and visualization, studies on the applicability in the construction industry are still at the initial stage. There are few studies on combining environmental monitoring and construction process by developing a system suitable for environmental management on construction sites. Moreover, the existing studies focus on enhancing the remote control of the environmental monitoring in the E-CPS while ignoring the impact of the environmental changes on decision-making. The functions of the E-CPS, such as early warning and auxiliary evaluation, are rarely performed to assess environmental management using E-CPS.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Author** & **Research Methods** & **Theme** \\ \hline [PERSON] et al. [9] & CPS + WSN + GPS + BIM & Monitoring greenhouses gas emissions of prefabricated buildings \\ [PERSON] et al. [8] & CPS + deep learning & Monitoring litter surveying and prediction of human \\ [PERSON] et al. [25] & CPS + WSN & Monitoring risk of air pollutant in urban areas \\ [PERSON] et al. [26] & CPS + IoT + cloud-edge orchestration & Monitoring production-status service and energy \\ [PERSON] et al. [27] & CPS + simulation modeling & Evaluating the system’s performance under adverse scenarios \\ \hline \hline \end{tabular}
\end{table}
Table 1: The main existing methods and themes in E-CPS.  
Hence, this study addresses the necessity and benefits of the E-CPS in environmental monitoring for construction sites.