# Location Optimization of Emergency Bell Based on Coverage Analysis for Crime Prevention
###### Abstract  
Typically, emergency bells are security facilities that, when activated, trigger an alarm and immediately dispatch a police car to prevent crime. However, there currently exists an ambiguity in the criteria for emergency bell installation. Consequently, this study aims to find an optimal location for emergency bells whilst considering several factors like cumulative crime incidents. In particular, we exploited emergency bell location data, data on five major crimes, and the geographic information of administrative dongs (primary division of districts) in this study. Specifically, we performed correlation analysis, principal component analysis, and K-means clustering for exploratory data analysis. To effectively cover all 17,437 crimes, which are not covered by the existing emergency bells in Gwangju metropolitan city from 2018 to 2021, the results from the implementation of the emergency bell location set-covering problem revealed the need for about 6228 emergency bells. More precisely, the emergency bell maximal covering location problem was employed to derive the coverage percentage for 250, 500, 800, 1000, and 1500 emergency bells. The results showed that 2850 emergency bells were required to cover over 80% of crime occurrence coordinates, saving over half of the budget compared with covering them all. Overall, this study is noteworthy in its potential role as a roadmap for the optimal placement of emergency bells for future crime prevention. M +
Footnote †: journal: Medical  
a CCTV-integrated control center through a dedicated CCTV network. Additionally, the broadcasting terminal, which is a voice-over-internet protocol (VoIP) device, transmits the signal from the emergency bell to the 112 emergency response centers. Precisely, the hub connects the VoIP broadcasting device to the emergency bell, while the modem establishes the connection between the VoIP broadcasting device and the internet [8]. Interestingly, the installation of emergency bells is a critical component of crime prevention, as it enables immediate response through a system. An activation of the bell triggers a warning light or alarm with a report sent to the 112 emergency response centers, initiating the dispatch of a patrol car (Figure 1). Meanwhile, the implementation of emergency bell systems to prevent crime is increasing in South Korea. Incheon City, for example, has been proactively installing emergency bells in crime-prone areas such as parks, public toilets, and civil complaint areas since 2014. Additionally, according to the revised act on public toilets, safety emergency bells must be installed in designated public restrooms starting from 20 July 2023 [9]. Furthermore, surveillance areas, applied to community safety planning activities, can effectively eliminate the possibility of criminal activity and reduce the fear of crime. Despite the establishment of individual guidelines by local governments for emergency bell installations, there is no clear strategy for their optimal placement. Recently, several studies on optimal locations using spatial analysis techniques such as geographic information systems (GIS), spatial statistics, and spatial optimization are in progress. In this sense, studying the optimal location for emergency bell installations is necessary to effectively investigate the balance between the benefits and potential costs. The objective of this study is to investigate the spatial distribution patterns of the emergency bells in Gwangju and subsequently employ a visibility analysis and spatial optimization method, utilizing actual data, to identify the most optimal location for emergency bells. This study highlights the importance of emergency bells and identifies the factors that influence their placement. By combining GIS with the mathematical models of maximal covering location problem (MCLP) and location set covering problem (LSCP), the optimal locations for emergency bells can be determined based on real-world data.