## 5 Discussion  
This study selected abnormal situation detection services using thermography cameras and selected priorities via service model evaluation via expert interviews. Thermography cameras enable preemptive detection of abnormal situations at night, abnormal weather, and pre-disaster phenomena that cannot be easily and immediately confirmed with regular CCTVs. This is because thermography cameras have a higher object recognition reliability at night, which is a limitation of CCTV RGB images, and clearly display temperature differences. However, it has the disadvantages of short object detection distance due to lower resolution than regular CCTVs and high equipment cost. Considering these factors, the installation locations of thermography cameras should be carefully selected. For instance, to prevent traffic accidents at night, thermography cameras should be selectively installed in intersections and roundabouts where pedestrian traffic accidents frequently occur and traffic volume is high. This approach can be also applied to areas where freezing and flooding frequently occur to ensure road safety. For crime prevention purposes, good locations to install cameras can include places with a high crime rate or that are desolate (e.g., parks and trails). Clearly, a spatial analysis is needed to select thermography camera locations in line with each installation's purpose and regional features. Technical discussions are also needed to implement and upgrade services. In some situations, maximizing service effects may be easy by merely utilizing thermography cameras. For instance, better object recognition and analysis effects can be achieved by using a thermal image combined with general CCTV images. Similarly, the reliability of temperature changes can be ensured by combining it with weather sensors (e.g., temperature, humidity, and atmospheric pressure), while temperature estimation and interpolation can be used to extend the detection distance of thermography cameras. After recognizing abnormal situations analyzed by thermography cameras, it is also necessary to contemplate how and to whom to convey it to. For instance, systems can alert or give an alarm to control managers, or even citizens around thermography cameras; if information is delivered to citizens, effective delivery methods such as text, image, and sound information should be considered. The utilization of active mobile equipment can be also considered. Thermography CCTVs, which are fixed at one location, have extremely limited control areas. Recent research and technology developments have been made in using mobile equipment, such as robots and drones, equipped with such cameras. For instance, a technology supporting autonomous driving via thermography modules can become a powerful tool to complement existing vision sensors [86; 87]. Mobile equipment-based thermography cameras can be utilized to minimize control blind spots and detect urban abnormalities more clearly. Government policy support is required to make thermography cameras widespread and ensure citizens' life safety. As mentioned earlier, thermography cameras require higher construction costs than general CCTV. Local governments, which are regarded as the main source of demand for the service model, spend substantial money to maintain existing control services; as such, they face difficulties in securing the budget for implementing new services. In particular, small and medium cities with poor financial conditions may need support from the central government, such as government matching funds and public offering projects. This service model, which can directly monitor citizen safety, requires economic efficiency analysis considering public benefits rather than a financial review that simply examines construction and operation costs. This is because expanding infrastructure for citizen safety and securing a social safety net are essential public goods.