## 2 Theoretical Background
### Case Studies on Fire-Extinguishing Drones
\begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt} p{142.3 pt} p{142.3 pt}} \hline \hline
**Study** & **Image** & \
\begin{tabular}{c} **Fire Extinguisher Deployment Method/Fire** \\ **Extinguisher Payload/Status of Experimental** \\ **Validation** \\ \end{tabular} \\ \hline [PERSON] (2018) [16] &
\begin{tabular}{c} - To address the difficulties and risks \\ associated with firefighting in high-rise buildings or mountainous terrains, a safe fire-extinguishing system consisting of six components (drone, robot, firefighting equipment, fire-extinguishing ball, collision-avoidance system, and camera) \\ was proposed. \\ - The system was demonstrated to be suitable for initial fire suppression, and the experimental results proved its ability to operate safely at heights where fire-extinguishing balls can be reloaded while maintaining drone stability. \\ - The potential utility of fire-extinguishing balls in the proposed firefighting system, which complements the traditional firefighting methods using drones and remote-sensing technology, was examined. \\ - The experimental results demonstrated that small-sized fire-extinguishing balls may not be effective against building fires but they can be effective for suppressing grass fires. \\ - A holder was designed to store fire-extinguishing balls for firefighting purposes. \\ - The holder consisted of a railing system attached to a base plate composed of an acrylic sheet. \\ - Using Arduino and servo motors, the release and blocking of the balls were controlled, while the rails guided the balls, and the barriers released and stopped the balls. \\ - A system that uses unmanned aerial vehicles (UAVs) for firefighting was proposed to facilitate quick, efficient access to the top floors of buildings and to improve firefighters’ visual access to affected areas. In this system, fire-extinguishing balls were used to prevent the spread of fire. \\ - This system was based on a newly designed firefighting UAV equipped with a mechanism to shoot and drop fire-extinguishing balls. The UAV was controlled using a 2.4 GHz radio frequency signal and video monitoring controller to operationalize the shooting and dropping mechanism. \\ - This firefighting UAV can be utilized effectively in the early stages of a fire, and its ability to enhance the safety and efficiency of firefighters was demonstrated. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of case studies related to fire-extinguisher drone research. These studies proved that fire-extinguishing drones are effective for rapidly responding to wildfires in mountainous areas and validated the efficiency of various fire extinguisher deployment methods. Proactive wildfire prevention and response can possibly be realized through continuous, controlled deployment of fire-suppressant balls. While research on single-shot fire-extinguisher deployment drones is underway overseas, studies on the reliability of the drones designed for continuous fire-extinguisher deployment are lacking. In this study, we implement six fire-extinguisher canisters and conduct practical research on firebreak construction through continuous fire extinguisher deployment to prevent the spread of fires.