## 3 Smart IoT Based Building and Town Disaster Management System (BTDMS)
### System Architecture  
The proposed system consists of the information layer, AI/big-data connection layer, service layer, and virtual layer as shown in Figure 3. The data obtained by the sensor is stored in the disaster management big-data (DMBD) of the information layer, and the AI/big-data connection layer enables the fire detection and fire occurrence prediction. Also, it provides service to inform the rescuers about the optimal evacuation route based on AR through the service layer and the virtual layer. Then the BDMS controls the actuators appropriately to cope with the fire. The functions of each layer are as follows:  
* **Information Layer**: In the information layer, there are many types of data such as building disaster management data, user location data, device and sensor data, user behavior data, and rescue  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Current System** & **Proposed System** \\ \hline \(\bullet\) & Current disaster management system through augmented reality (AR) technology is mostly focused on education and experiential technology \\ \(\bullet\) & There are few systems for rapid construction, simulation, and guiding for evacuation in smart buildings \\ \(\bullet\) & No remote management system based on AR and IoT, which can cope with the real fire department \\ \(\bullet\) & No appropriate alternative as the systematic destruction by the fire progresses \\ \hline \hline \end{tabular}
\end{table}
Table 3: Differences with the existing system.  
situation monitoring data in the information layer. Disaster environment information collected from the sensors are stored and processed in the DMBD. The IoT sensors gather the disaster environment information and send the data to the DMBD. Rescue situation monitoring data created through the IoT disaster control agent (IDCA) are stored in the real time rescue situation monitoring data module, and the enhanced/updated data is sent to the IDCA;
* **AI/Big-Data Connection Layer**: The AI/big-data connection layer implements the key roles in the disaster management system and classifies building information data, device information data, user information data, and real time rescue situation monitoring analysis data coming from the information layer for the disaster forecast and management service. The building disaster management server (BDMS) in the AI/big-data connection layer is composed of building disaster context management (BDCM), disaster situation data management (DSDM), AI-based building data analyzer (ABDA), and IoT disaster control agent (IDCA). The roles of BDCM are management of fire disaster, environmental context, and user location, data gathering information, and data storage. The DSDM manages the lists of disaster management service and the way of IoT sensors/actuators and provides necessary information. Thus, the AI/big-data connection layer is classified as fire context awareness, fire spread prediction, and optimum evacuation space analysis coming from the information layer through the ABDA and the IDCA;
* **Service Layer**: The service layer is where the optimum disaster management evacuation takes place; it provides services such as the fire context awareness, fire spread prediction, optimum evacuation space analysis, and actuator integrated control, etc. It is responsible for providing optimum service to users and receiving disaster control information from the IDCA. It is composed of disaster management service design (DMSD), disaster management service organization (DMSO), IoT based disaster management service (IDMS), and IoT service resolution (ISR) module;
* **Virtual Layer**: The virtual layer provides a service that confirmation of evacuation place. It selects the best fit evacuation place and provides AR-based optimum escape guidelines. Also, it provides the safety facilities information for AR-based intelligent configuration of the safe/unsafe area.