Abstract:

The threat of natural disasters such as torrential rain and massive floods is increasing year by year. Typhoon No.15 (Faxai), which occurred in September 2019, landed in the Kanto region in Japan with the strongest force ever observed. Faxai caused severe rains and substantial floods in a short period of time, which disrupted the road network in the area. This effect caused a large-scale blackout in Chiba Prefecture for about three weeks. The disconnection of the mobile phone network and other communication networks continued longer than the large-scale power outages. Typhoon No.19 (Hagibis), which landed in October, caused record heavy rain in the Kanto and Tohoku regions. Because of this heavy rain, levee breaches occurred extensively and simultaneously at 140 locations in 71 rivers, and the ensuing massive flood caused 93 casualties. Climate change makes tropical cyclones more and more violent, and the damage is clearly getting bigger. The report of World Meteorological Organization describes average temperatures for the past ten years (the 2010 to 2019 period) as almost certain to be the highest on record. Furthermore, 2019 is on course to be the second or third warmest year on record.

Even now, about one and a half months after the massive flooding by Typhoon Hagibis, approximately 600 people from 245 households are staying at the evacuation center in Nagano City in the affected area. In Fukushima and Miyagi prefectures, evacuation centers continue to operate in the same way as Nagano City. In addition, in the Great East Japan Earthquake that occurred in 2011, more than 20,000 victims even continue to live in 73 evacuation centers 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.

As the phases of evacuation life change, the proportion of daily life activities, such as resuming studying, gradually increases. This “daily life under non-daily life conditions” will continue until they leave the evacuation center. Generally, shared Wi-Fi service is installed at the evacuation center. However, these communication environments have high latency and communication is interrupted. The current e-learning environments can always communicate and are built on the assumption of a high-speed and low-latency communication environment that is not suitable for use in these low-quality communication environments. We must therefore construct an e-learning environment that assumes a low-latency communication environment with unstable connection conditions in a disaster situation.

In this study, we design an asynchronous learning assistance framework for disaster situations. A virtual network technology separated from the Internet is used to design an environment where learning can continue even if the PC or smartphone used by the learner is not connected to the Internet. This learning assistance framework behaves as if a stable Internet connection is maintained even if the connection is lost. We aim to support the continuous use of e-learning in “daily life under non-daily life conditions” from the middle to the end of evacuation shelter life. In addition, we explain the design of a learning assistance framework for disaster situations, and that the experimental results of the execution environment are implemented as a prototype, according to effectiveness.

Keywords:

e-learning, disaster reduction for learners, client-side virtualization, high latency internet.