Abstract:

The threat of natural disasters such as torrential rain and massive flood is increasing year by year. In July 2020, torrential rains and massive flooding occurred mainly in the Kyusyu region of Japan. The 24 and 48-hour precipitation totals were the highest ever recorded at many meteorological stations. As a result of this disaster, up to 8,800 households in Kumamoto Prefecture in Kyushu region were affected by power outages. Many houses were affected by water supply cuts and communication problems. Climate change makes torrential rain and massive floods more and more violent, and the damage is clearly getting bigger. The report of World Meteorological Organization describes, 2020 was the warmest year on record so far. The period from 2011 to 2020 was the hottest decade in recorded history.

The July 2020 torrential rains resulted in more than 10,963 evacuees during the peak period. In Hitoyoshi City, Kumamoto Prefecture, which suffered particularly heavy damage, evacuation centers continued to be operated until the end of 2020. In the Great East Japan Earthquake that occurred in 2011, more than 20,000 victims continued to live in evacuation centers at 73 evacuation centers even seven months after the disaster. In natural disasters caused by climate change and disasters caused by huge earthquakes and tsunamis, it is inevitable that the evacuation period will be prolonged.

Due to changes in the phase of evacuation life, the proportion of daily life such as resuming studying in the evacuation life gradually increases. This "daily life under the non-daily life" will continue until they leave the evacuation center. Generally, shared Wi-Fi service is installed at evacuation center. However, these communication environments have high latency and the communication is interrupted due to normal evacuees collect disaster information. The current e-learning environments can always communicate, and it is built on the premise of a high-speed and low-latency communication environment and is not suitable for use in these low-quality communication environments. We must construct an e-learning environment that assumes a low-latency communication environment with unstable connection conditions under the disaster situation.

In this study, we developed an asynchronous learning assistance framework for disaster situations. We implement a feature-limited LMS service using a power-saving IoT device. This IoT device is equipped with Wi-Fi capabilities and behaves as an access point for a limited number of users. The IoT device will function as an edge device that integrates a limited function version of the LMS and a communication status monitor. This learning assistance framework based on custom edge device behaves as if a stable internet connection is maintained even if the internet connection is lost. We aim to support the continuous use of e-learning in “daily life under the non-daily life” from the middle to the end of evacuation shelter life. Additionally, we explain how to preserve learning history on the proposed asynchronous learning assistance framework, and it is explained the experimental results of the execution environment implemented as a prototype, and effectiveness.

Keywords:

e-learning, disaster reduction for learners, edge computing, unstable communication conditions.