• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.63-71
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• 2019

Recently, there has been a lot of research on the construction of smart factory in the 4th Industrial Revolution era. Among the various technologies involved in the deployment of smart factory, one of the key technologies is the IoT protocol sector that handles the transmission and reception of data. In this regard, the MQTT protocol is generally used most commonly, but the existing MQTT technology lacks the concept of priorities of messages, so it is somewhat insufficient to be applied to an industrial field requiring real-time property. Priority handling of urgent messages is critical, especially in emergency situations, such as the emergency shutdown of the entire relevant facility following the failure of a particular facility. To improve this, research on priority-based MQTT is being conducted somewhat, but these studies have problems with actual field use because they are a variant of the MQTT standard. Therefore, this study conducts and verifies studies related to MQTT, which can prioritize messages while adhering to existing MQTT standards.

• Journal of People, Plants, and Environment
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• v.22 no.1
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• pp.31-38
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• 2019

Experiments were carried out to investigate the effects of mosses on the removal of particulate matter (PM 10) and volatile organic compounds (VOCs) in an indoor space and on the composition of air. For particulate matter removal experiments, 0.2 g mosquitto coil was burned in a glass chamber, where three kinds of mosses (Plagiomnium cuspidatum, Myuroclada maximowiczii, Etodon luridus) were placed. For VOCs removal experiments, 1 mL paint thinner was volatilized in a glass chamber, where Plagiomnium cuspidatum and Myuroclada maximowiczii were used. As a result, it was found that particulate matter was effectively removed by the three mosses, and the removal efficiency of particulate matter increased as the amount of mosses increased. The amount of VOCs was similar to the level in the control when a low amount of mosses (2 and 4 plates) was used. However, the removal efficiency of VOCs was significant when 6 plates of mosses were used. On the other hand, formaldehyde concentration was 40 times more than the control and carbon monoxide 30 times, when 0.2 g of mosquito repellent was completely burned in a glass chamber. Also formaldehyde removal effect was significant when 6 plates of mosses were placed. However, there was no change in the concentration of indoor oxygen, temperature and humidity by moss plants. In conclusion, the moss plants were effective in removing particulate matter and VOCs, and they are expected to be used for indoor decoration and landscape in order to improve indoor air quality in the future.