Hiroaki Yuze

Large Scale Distributed Disaster Information System based on MANET and Overlay Network

In the case of large scale disaster, such as earthquake, volcanic explosion, sea wave, more robust and flexible nation-wide disaster information network is required not only for governmental supporters but also residents and volunteers than business oriented network to communicate each other even though some parts of the network and information system are destroyed and disconnected. In this paper, we introduce a larger scale distributed disaster information network system based on mobile ad hoc network (MANET) and overlay network. MANET is used for the access network for residents and volunteers around the disaster area and evacuation places. The evacuated residents and volunteers can flexibly communicate with others though MANET using IP based terminals, wireless IP telephones and Mobile PCs. On the other hand, overlay network is applied for national wide government and local government network to provide robust and redundant large scale disaster information network. By combining with both MANET access network and overlay network, more robust and flexible, and large scale disaster information network system can be realized provide even some of network lines and nodes are damaged and destroyed when the disaster happened.

Robust and Large Scale Distributed Disaster Information System over Internet and Japan Gigabit Network

In this paper, a robust and large scale resident-oriented safety information system on the occurrence of the various disasters constructed over a nationwide high-speed network is introduced. The evacuated residents can register their safety information to the local safety information servers in the evacuation area whether they can safely evaluated or not using mobile PCs or terminals at the evacuation place or mobile terminals on the way of evacuation. All of the local information servers are connected each other by wireless network and the safety information can be sent an upper-layer database in the district area and finally integrated into a district safety information in that region. In our system some of the damaged local servers due to the disaster can be detected and recovered by the upper- layer database server. On the other hand, the upper-layer database servers are backed up by mirror servers located at mutually different locations with long distance to isolate the influence of the same disaster when the some of them were destroyed or disordered. Thus, by introducing two levels of redundancy and backup functions, more large scale and robust safety information database system can be realized.

Development of Smartphone Application for Off-Line Use in Case of Disaster

When large earthquakes occur, affected inhabitants lose access to phones and the Internet. To provide immediate assistance to disaster victims, we developed a disaster prevention application that is available off-line, and that has the following characteristics. 1) When communication infrastructures are damaged, the functions of the developed application work off-line. 2) During large-scale disasters, such as the Tokai earthquake and the resulting tsunami, users can examine the inundation range prediction of tsunamis and can read a suitable disaster prevention manual. 3) The developed application is compatible with common, portable devices. We developed an iPhone application and then conducted experiments to evaluate its usefulness. Next, based on the user feedback, we made improvements and then developed an Android application and subsequently evaluated it.

Light-Weight Safety Confirmation System for Large-Scale Disasters

We have been developing and operating safety confirmation systems for universities since 1999. The Great East Japan Earthquake in 2011 clarified some issues related to the safety confirmation systems. Thereby, we reviewed the safety confirmation systems, the result of which revealed that more carefully selected functionality, restriction on the volume of communication, and enhanced anti-disaster feature of the systems would be required. We have then developed the light-weight safety confirmation system that does not have the function to simultaneously transmit mass emails and is designed for easier system migration. Evaluation was conducted by performing demonstration experiments of the newly developed safety confirmation at a disaster prevention drill of a university.

Improvement of the Survivor Information System for University

We developed the survivor information system in preparation for a large-scale disaster like the Tokai earthquake. In this system, students and university staffs can register their survivor information using a personal computer or a mobile phone. We had operated this system for six years. And we improved the system during this period. When the new influenza was going around all over the world, we added the new function of the countermeasure against the new influenza to the survivor information system. The earthquake of magnitude 6.5 happened to the Suruga Bay on August 11, 2009. Then, we used the survivor information system, in order to check the safety of students and university staffs. After the earthquake, we took the questionnaire about system use to the university staff and improved the system based on the questionnaire result. In this paper, we report the outline and the improving point of the survivor information system. Especially we describe the improving point for the countermeasure against the new influenza. We also describe the questionnaire result about use of the system after an earthquake, and the improving point based on a questionnaire result.

Development of Autonomous Anti-Disaster Base Station by Combination of Satellite and Wireless Networks

When a large-scale disaster occurs, it is crucial to secure means of communication. However, as the damage to the communication networks might be aggravated as the magnitude of the disaster becomes larger, it would likely cause a state where all communications are disrupted. In addition, as the amount of damage to the power plant and transmission line becomes more significant, it could disrupt the supply of electricity over an extended period of time. The purpose of this research is to develop an autonomous anti-disaster base station that houses a power supply system, which uses both solar panels and batteries as the source of power, and has satellite Internet and wireless LAN environment so as to contribute to the securing of Internet communication immediately following a great earthquake. We developed a prototype system of the autonomous anti-disaster base station that features two types of satellite Internet connection equipment. The prototype system was put through a demonstration experiment during an anti-disaster drill held at a university. During the anti-disaster drill, the students of the university that evacuated to a sports field used their own smart devices to connect to the wireless LAN access point of the prototype system and registered their safety information into the safety confirmation system of the university through the satellite Internet. The access log of the safety confirmation system allowed us to verify that access was successfully made to the safety confirmation system through the prototype system. In addition, we conducted a questionnaire survey of the university students following the drill and were able to verify the usefulness of the system.

Large Scale Disaster Information System Based on P2P Overlay Network

When a large-scale disaster occurs, information sharing among administration, residents, and volunteers is indispensable. However, as reported, a lot of examples show that it is difficult to use well. The Disaster Information System is not built on the infrastructure which the system failure was considered at the disaster is nominated for the cause. In this study, we focus on the operation usability of the Disaster Information Sharing Systems works at each area, and share the resources of those systems with the P2P overlay network, by decentralizing and integrating the disaster information to realize the redundancy of the system. For the disorder between the nodes and the communication links, we propose a mechanism to detect the faults in order to improve the robustness of the system.

Large Scale Distributed Disaster Information System Based on Nation-Wide Highspeed Network

In this paper, a robust and large scale resident-oriented safety information system on the occurrence of the various disasters constructed over a nationwide high-speed network is introduced. The evacuated residents can register their safety information to the local safety information servers in the evacuation area whether they can safely evaluated or not using mobile PCs or terminals at the evacuation place or mobile terminals on the way of evacuation. All of the local information servers are connected each other by wireless network and the safety information can be sent an upper-layer database in the district area and finally integrated into a district safety information in that region. In our system some of the damaged local servers due to the disaster can be detected and recovered by the upper-layer database server. On the other hand, the upper-layer database servers are backed up by mirror servers located at mutually different locations with long distance to isolate the influence of the same disaster when the some of them were destroyed or disordered. Thus, by introducing two levels of redundancy and backup functions, more large scale and robust safety information database system can be realized

Development of Light-Weight Information Sharing System for Disaster Volunteer Headquarter

During a large-scale disaster, smooth information distribution and sharing between Prefectural and Local Disaster Volunteer Headquarters is crucial in enabling local social welfare councils to conduct efficient disaster-relief activities. Disruption of communication lines and blackout are common during large-scale disasters, which would disable high-speed Internet connection. We have developed a light-weight information sharing system for Shizuokaken Disaster Volunteer Headquarters. This system operates on a cloud server, and its files are light. Because it is a text-based system, the communication volume is small and suitable for narrowband communications, such as satellite telephone. This system is already in practical use at Shizuokaken Council of Social Welfare.

Experimental Variables of Urban Disaster Information System Influenced by Moving Object

In this paper, the influence of our proposed Urban Disaster Information System by moving objects is experimented and discussed. It is widely known that the network conditions between wireless node and the setup wireless LAN (Access point) is influenced by moving objects like cars, animals, and bullet train. Therefore, Disaster Information System in urban area is necessary to consider with the influences by such moving objects in order to maintain QoS like audio and video transmission. The field experiment is held by using moving cars and rains, and the observed results are discussed for the influence for the our proposed Disaster Information Networks.