## 5 Smart Community
### Smart Environment Management
#### 5.1.1 Air Quality Monitoring  
Air quality monitoring involves managing both the interior and exterior air quality monitoring. Internal air quality monitoring focuses on monitoring humidity and temperature to provide a suitable environment for human beings and special objects, such as books in a library. To improve the performance of the built environment in order to provide comfortable living environments and improve energy efficiency, [PERSON] et al. [37] introduced a low-cost, high-resolution IoT system at the University of Westminster's Marylebone Campus in central London. This system can monitor environmental parameters such as carbon dioxide, dry-bulb temperature, illuminance level, relative humidity and sound levels. By detecting these environmental factors, the IoT system can intelligently adjust the operation of indoor air conditioning equipment to ensure environmental comfort and save energy consumption. To protect cultural collections and prevent the risk of manual data collection, [PERSON] et al. [38] developed MonTreAL, a library-wide IoT system for monitoring humidity and temperature. Further, [PERSON] et al. [39] expanded MonTreAL and introduced SensIoT, a general sensor monitoring framework for the IoT. Its most prominent feature is the use of Docker and Docker Swarm to solve common software problems and enable flexible data collection. The SensIoT system is an open-source sensor monitoring system that enables easy deployment and maintenance while remaining flexible and scalable. [PERSON] et al. [40] developed an IoT system to monitor energy consumption through the measurement of CO\({}_{2}\) levels, temperature, and humidity. The measurement of CO\({}_{2}\) levels, temperature, and humidity helps to establish air conditioning schedules and improve a building's heating, ventilating, and air conditioning. They use sensors to measure temperature [38; 39] and humidity [38; 39]. The sensor model DHT-22 can both record temperature and humidity [38]. Other humidity sensors are ASH2200 [39], DHT11 [39], AM2302 [39]. The IoT system continuously monitors changes in humidity and temperature to keep cultural collections in a suitable environment throughout the day for long-term preservation. External air quality monitoring is mainly focused on urban transportation. [PERSON] et al. [41] deployed an IoT air quality monitoring system on the main roads in Taipei to monitor carbon monoxide concentrations caused by vehicle emissions. Similarly, [PERSON] et al. [42] deployed IoT systems at crossroads and main roads in Taipei to monitor carbon monoxide levels in urban areas. [PERSON] et al. [43] used an IoT system to monitor air pollution levels caused by transportation in Hanoi. They visualized the data using calibration and data clustering techniques, mathematical interpolation methods, and computer graphics. In recent years, low-cost IoT systems for air quality monitoring have become one of the new trends. [PERSON] et al. [44] developed a low-cost and wearable IoT system to collect environmental data robustly. [PERSON] et al. [45] also developed a low-cost IoT system, Eclipse, to monitor Chicago's outdoor air quality and found that the system reliably collected data for more than 90% of the expected hours. Last but not least, [PERSON] et al. [46] reported on IoT Environmental Monitoring systems in Florence, Helsinki, and Cagliari. For external air quality monitoring, people usually use sensors to collect air quality data and weather data to build up a more comprehensive and accurate IoT system for air quality monitoring. Table 2 presents the parameters collected for air quality data. Table 3 presents the parameters collected for weather data. PM concentration seems to be the main monitoring indicator. Recently, focus has been more on the cost of the sensor. Scholars have begun to utilize low-cost sensors to collect air data. [PERSON] et al.