## 2 Materials and Methods
### System Prototype
#### 2.2.3 Identifying Requirements and Functional Architecture  
In system development, a systematic review can help identify the key requirements for a new system by gathering and analyzing existing research, user feedback, and other relevant data. After completing a systematic review, the findings can be used to develop a list of requirements for the system being developed [19]. These requirements should be specific, measurable, and aligned with the goals of the project. This list of requirements informs the rest of the SDLC methodology.  
The requirement-gathering phase is critical to the success of the entire system development process. By using a systematic review to inform this phase, one can ensure that the requirements are based on sound evidence and are aligned with the needs of users and stakeholders. Therefore, a previous systematic review study was conducted [9], which included 45 publications presenting previous efforts to use civilian drones in safety and security applications. The review's findings revealed that drones with basic sensors (for GPS and cameras), advanced sensors, and advanced software were commonly used. As shown in Figure 6, 71% of the reviewed studies used basic sensors for GPS, and 64% used basic camera sensors, while over half used advanced sensors (51%) and advanced software (56%). Based on these insights from existing deployments, two versions of the D4S are proposed: the Basic-D4S (B-D4S) and the Advanced/Assisted-D4S (A-D4S). The basic version of the system has been designed to enable quick deployment with minimal approval required for safety and security personnel to utilize it in their operations, while the other system, which requires advanced facilities and more approvals, is intended for advanced missions. This approach allows safety and security professionals to undergo digital transformation and begin adopting drones in their operations.  
The functional architecture of the D4S is illustrated in Figure 7 and mainly includes four components: the drone or UAV part, a wireless communication channel, ground control, and a remote command-and-control center. Such a functional architecture enables enhanced situational awareness for dynamic decision making for safety and security personnel by transmitting captured video images, location data, and other telematic data from sensors in real time to the ground control center in the B-D4S version of the system and the CCC in the A-D4S version. The received video image and telematic data, along with the location data, will be plotted on a GIS map. For the CCC, which is mainly part of the A-D4S version of the system, specialized databases specific to each type of operation and AI decision support systems (AI-DSSs) can provide safety and security personnel with extra assistance, enabling better situational awareness and dynamic decision making involving both human and machine elements.  
\begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{1}{c}{**No.**} & \multicolumn{1}{c}{**Hypothesis**} \\ \hline H1 & PU positively affects BI2U. \\ \hline H2 & PEoU has a strong indirect positive relationship with BI2U. \\ \hline H3 & PEoU has a less strong direct positive relationship with BI2U. \\ \hline H4 & BI2U has a strong positive impact on system usage. \\ \hline H5 & PU and PEoU have a strong positive impact on BI2U. \\ \hline \hline \end{tabular}
\end{table}
Table 2: Adopted hypotheses [17].  
\begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{1}{c}{**Construct Items**} \\ \hline \multirow{2}{*}{**Behavioral Intention to**} & 1. I think that using the new D4S is a good idea. \\  & 2. I think that using the new D4S is beneficial. \\  & 3. I have a positive prescription about using the new D4S. \\ \hline \multirow{2}{*}{**Usage**} & 1. I intend to use the new D4S. \\  & 2. I intend to use the D4S instead of the traditional procedure. \\ \hline \hline \end{tabular}
\end{table}
Table 1: _Cont._