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Nguyen H.N.,Disaster Management and Mitigation Group | Nguyen H.N.,Vietnam National University, Hanoi | Gyoda K.,Disaster Management and Mitigation Group | Gyoda K.,Shibaura Institute of Technology | And 6 more authors.
Journal of the National Institute of Information and Communications Technology | Year: 2011

In case of disasters, telecommunication infrastructure might be destroyed rising the demand of fast-deployment emergency wireless communication systems in order to provide communication services to victims and rescue teams. Recently, mobile ad hoc communications is considered as an efficient solution for emergency communications in disaster areas. Beside the advantages in terms of fast deployment and self-configuration capability, ad hoc communications networks show less performance in large scale networks. In this paper, we first discuss some proposed ad hoc based emergency communications models for wide scale disaster management. Then we present a hybrid system model of wireless data networks for emergency communications in disaster areas. Due to limited radio resource, resource management plays an important role to system performance and provide user's QoS. We propose a resource management scheme for the hybrid wireless networks in which selected powerful end users operate as temporary relay hosts (TRH) in order to utilize the system resource efficiently. The scheme combines network controlled handover, resource allocation and admission control and takes advantages of adaptive transmission rates and multi-hop/relay communication mode. Performance results obtained by computer simulation show that using the proposed resource management scheme can reduce the connection blocking probability i.e. increase the quantity of simultaneous connections.


Okada K.,Disaster Management and Mitigation Group | Okada K.,University of Electro - Communications | Okada K.,Wireless Network Research Institute | Nguyen H.N.,Disaster Management and Mitigation Group | And 3 more authors.
Journal of the National Institute of Information and Communications Technology | Year: 2011

Mobile phones come into wide use now and many people usually carry about and are familiar with using them. So, mobile phone becomes a very useful communication tool in large scale disasters. But it often cannot use, because congestion occurs owing to large demand of calls by which people wants to know their family with accidents or without accidents, non-functional base stations occur owing to cable cutting or long time power failure. As countermeasures to these issues, we study the holding time limitation and the emergency multi-system access, in the project of researches on network control technologies in disasters. This paper describes the outline of our studies.


Gyoda K.,Shibaura Institute of Technology | Gyoda K.,Disaster Management and Mitigation Group | Nguyen H.N.,Disaster Management and Mitigation Group | Nguyen H.N.,Vietnam National University, Hanoi | And 8 more authors.
Journal of the National Institute of Information and Communications Technology | Year: 2011

The wireless ad hoc network is expected to be used as an alternative of the existing mobile communication network to make users communicate when a large-scale disaster occurs. It is also expected to be deployed to search robot rescue system in a closed space of disaster struck area. In this paper, we propose two communication models by use of wireless ad hoc network. One is a real city communication model considering the disaster occurs. The other is a search robot communication model in the closed spaces. We analyze and evaluate the communication performance of these two network models by using the network simulator.


Jeong B.-P.,Disaster Management and Mitigation Group | Jeong B.-P.,Japan National Research Institute of Fire and Disaster | Takizawa O.,Disaster Management and Mitigation Group | Takizawa O.,Security Fundamentals Group | And 8 more authors.
Journal of the National Institute of Information and Communications Technology | Year: 2011

Drawing on its extensive experience with natural disasters, Japan has been dispatching Japan Disaster Relief (JDR) team to disaster-stricken countries to provide specialist assistance in rescue and medical operations. The JDR team has assisted in the wake of disasters including the 2004 Indian Ocean Earthquake and the 2008 Sichuan Earthquake in China. Information about the affected area is essential for a rapid disaster response. However, it can be difficult to gather information on damages in the immediate post-disaster period. To help overcome this problem, we have built on an Earthquake Damage Estimation System. This system makes it possible to produce distributions of the earthquake's seismic intensity and structural damage based on pre-calculated data such as landform and site amplification factors for Peak Ground Velocity, which are estimated from a Digital Elevation Model, as well as population distribution. The estimation result can be shared with the JDR team and with other international organizations through communications satellite or the Internet, enabling more effective rapid relief operations.


Hada Y.,Disaster Management and Mitigation Group | Hada Y.,Kogakuin University | Takizawa O.,Disaster Management and Mitigation Group | Takizawa O.,Security Fundamentals Group | Takizawa O.,Office of Technology Transfer
Journal of the National Institute of Information and Communications Technology | Year: 2011

Conventional wireless ad-hoc network has many restrictions such as low rate, low reliability, delay of transmission, and restriction on node positions. In order to solve these problems, we propose new concept network; wired-wireless hybrid ad-hoc network. Efficiency of the new concept network has been evaluated by simulation. We adopted the network to long-distance remote control of rescue robots. Field experiments using prototype system have been frequently performed, and we achieved long-distance (700m) remote control of rescue robots. Thereby, the long-distance search activities of danger area were attained.


Jeong B.-P.,Disaster Management and Mitigation Group | Jeong B.-P.,Japan National Research Institute of Fire and Disaster | Takizawa O.,Disaster Management and Mitigation Group | Takizawa O.,Security Fundamentals Group | And 3 more authors.
Journal of the National Institute of Information and Communications Technology | Year: 2011

We have developed a cellular phone application "Easy-Reporter" that simplifies the process of initial damage report to the disaster response headquarter, where a report is comprised of the GPS location, photos and the predetermined event categories selected by the user. It can be used to collect safety information under the normal circumstance such as disaster drills as well as the emergency conditions such as communication congestion after a large scale earthquake.


Takizawa O.,Disaster Management and Mitigation Group | Takizawa O.,Security Fundamentals Group | Takizawa O.,Office of Technology Transfer | Hosokawa M.,Japan National Research Institute of Fire and Disaster | And 3 more authors.
Journal of the National Institute of Information and Communications Technology | Year: 2011

At the time of a catastrophic calamity in which a telecom infrastructure receives a serious damage, the structure which shares information electronically and carries it simply by the help is useful. RFID (Radio Frequency IDentification Tag) which is one of the ubiquitous devices is a device which enables exchange of electronic data locally and can be utilized as data storage in the information exchange at the time of a disaster. This paper describes the research-and-development result about disaster prevention application of RFID in the Disaster Management and Mitigation Group.


Takizawa O.,Disaster Management and Mitigation Group | Takizawa O.,Security Fundamentals Group | Takizawa O.,Office of Technology Transfer | Sonoda K.,Nagasaki University | And 4 more authors.
Journal of the National Institute of Information and Communications Technology | Year: 2011

We research the multimedia information hiding (MIH) which is a technology to overlay digital information on multimedia contents such as picture, sound, document, etc. As application to disaster management of MIH, we have developed a new technology called "PAIH" (Public Address Information Hiding) which is a technology to overlay information such as position or destination on siren sound of urgent vehicles. Siren sound is allowed to degrade of sound quality, but PAIH is required to decode correct information from siren sound with pitch shift (Doppler effect) or under noisy environment.

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