Yoshitaka Shibata

Iwate Prefectural University, Japan

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Publications (160)12.55 Total impact

  • Source
    Quang Tran Minh · Yoshitaka Shibata · Cristian Borcea · Shigeki Yamada
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    ABSTRACT: Catastrophic disasters can destroy large regions and, in the process, leave many victims isolated from the rest of the world. Recovering the communication infrastructure is typically slow and expensive, which is not suitable for emergency response. Multihop wireless access networks have the potential to quickly provide Internet connectivity to victims, but so far no simple and practical solution has been proposed to help people configure these networks easily. We are pursuing the approach of utilizing wireless virtualization techniques to establish wireless access networks on-the-fly using on-site mobile devices. While our previous work has demonstrated proof-of-concept solutions, it lacked fundamental communication abstractions, a rigorous design, and a thorough analysis on the effectiveness of these solutions. The main new contributions of this article are: (1) the wireless multihop communication abstraction (WMCA) as a fundamental communication concept for a practical tree-based disaster recovery access network (TDRAN), (2) the complete design and implementation details of TDRAN, and (3) a comprehensive analysis of the effectiveness of the proposed approach based on field experiments, both in indoor and outdoor settings, at different sites in Japan. The results demonstrate the effectiveness of the proposed solution for on-site configuration of wireless access networks, as it can easily extend to 20 hops by 15 m-distance and 16 hops by 30 m-distance networks, which result in 300 m and 480 m (respectively) in radius or about 1 km in diameter. This work also confirms that our approach is ready for realization as a real disaster recovery solution.
    Preview · Article · Jan 2016 · Ad Hoc Networks
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    ABSTRACT: The recent development of the society has caused new types of problems such as gaps of depopulation, population aging, and income between urban areas and local areas. The gap of communication networks is also one of the problems, and the poor network circumstance in local areas might affect the future medicare or welfare services by using Information Technology. Also, when there is a natural disaster such as earthquakes or typhoon, these local areas are likely to isolate from others because of disconnection of communication cables or breakdown of network devices. Therefore, this paper proposes Autonomous Flight Wireless Nodes (AFW) for the resilient networks consisted of Delay Tolerant Networks and Never Die Networks, and it is aiming to communicate with isolated areas. In the proposed methods, IP network based drones support data transmission by the autonomous flight with seeking possible wireless stations and sending the message data by the proposed resilient network. Then, the implementations of the proposed methods are introduced, and the results of wireless network conditions by the field experiments are reported in this paper.
    No preview · Article · Jan 2015
  • Source
    Goshi Sato · Noriki Uchida · Yoshitaka Shibata
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    ABSTRACT: In order to temporally recover the information network infrastructure in disaster areas from the Great East Japan Earthquake in 2011, various wireless network technologies such as satellite IP network, 3G, and Wi-Fi were effectively used. However, since those wireless networks are individually introduced and installed but not totally integrated, some of networks were congested due to the sudden network traffic generation and unbalanced traffic distribution, and eventually the total network could not effectively function. In this paper, we propose a disaster resilient network which integrates various wireless networks into a cognitive wireless network that users can use as an access network to the Internet at the serious disaster occurrence. We designed and developed the disaster resilient network based on software defined network (SDN) technology to automatically select the best network link and route among the possible access networks to the Internet by periodically monitoring their network states and evaluate those using extended AHP method. In order to verify the usefulness of our proposed system, a prototype system is constructed and its performance is evaluated.
    Preview · Article · Jan 2015 · Mobile Information Systems
  • Go Hirakawa · Phyu Phyu Kywe · Kenta Ito · Yoshitaka Shibata
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    ABSTRACT: Recently, reduction cost and size of the on-board sensor, the development of ITS and the spread of smartphones bring significant progress to the automotive information environment. In this paper, we introduce the COMOSE (Co-Operative MObile Sensor Environment) platform that collects sensor information using the wireless plug-and-play technology, to realize the effective utilization of the sensor information on a distributed network.
    No preview · Conference Paper · Jul 2014
  • Noriki Uchida · Noritaka Kawamura · Tomoyuki Ishida · Yoshitaka Shibata
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    ABSTRACT: Many cities or towns are located in mountain and sea areas, and these areas would be isolated from others because of the disconnection of networks or transportation if a large scale disaster should happen. In this paper, Delay Tolerant Networking (DTN) based on the Data Triage Method with the user policies and the Autonomous Flight Wireless Nodes (AFW) based on autonomous flights and data deliveries are introduced. In the proposed system, the drone with wireless interfaces is applied, and it actively supports the proposed DTN routings for the Disaster Information System (DIS). That is, the AFW automatically flies for seeking possible wireless nodes, send and receive disaster information by the proposed DTN routings, and return to the possible stations that wireless charge units are equipped when the battery needs to charge. Then, the implementations and the field experiments are discussed for the effectiveness of the proposed methods.
    No preview · Conference Paper · Jul 2014
  • Kenta Ito · Go Hirakawa · Yoshitaka Shibata
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    ABSTRACT: Japan is prone to natural disasters occurring including earthquakes, tsunami, typhoon, heavy rain and snow. A wide range and quick information gathering systems are needed after a disaster has occurred. In addition, wireless networks are very useful at a disaster has occurred. By using wireless networks, we can build a network quickly using moving vehicles. But there is a challenging communication environment in hilly and mountainous areas and after a disaster has occurred where communication is completely disabled. In this paper, we introduce SODiCS (Spatial and Temporal Omni directional Video Distribution and Collection System) for challenged communication environment. Data gathered using Omni directional camera and sensor is transmitted to all of the users through a web application. The user can see the data gathered on GIS map as a web service. We equipped the system with two modes of video distribution functions, Live View mode and Storage View mode. The system configuration and architecture are explained and a prototype system is constructed to evaluate the performance of our system.
    No preview · Conference Paper · May 2014
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    ABSTRACT: In this research, we build the system which can gather safety information to the disaster countermeasures headquarters by adjusting refugees information quickly in the evacuation centers at the time of wide-scale disaster. In this system, use of the personal number card issued by social security number program is assumed. Using this personal number card, the refugees information is registered into the Refugees Personal Information DB Server. The registered refugees information is gathered by the disaster countermeasures headquarters, and evacuation center information is publicized from each local government. By practical use of this research, at the time of wide-scale disaster like the Great East Japan Earthquake, this system realizes quick gathering of refugees information. Relief supplies can be correctly rationed to each evacuation center by the disaster countermeasures headquarters grasps refugees detailed information.
    No preview · Conference Paper · May 2014
  • Goshi Sato · Noriki Uchida · Yoshitaka Shibata
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    ABSTRACT: In order to temporally recover the information network infrastructure in disaster areas on the East Japan Great Earthquake on March 11, 2011, various wireless network technologies such as satellite IP network, 3G, Wi-Fi were effectively used. However, since those wireless networks are individually introduced and installed, but not totally integrated, some of networks were congested due to the sudden network traffic generation and unbalanced traffic distribution, eventually the total network could not effectively function. In this paper, by integrating those wireless networks into a cognitive wireless network, user can use this cognitive network as an access network to Internet by selecting the best network even though the serious disaster occurred. We introduce an OpenFlow based access network to automatically select the best network link and route among the possible access networks to Internet by periodically monitoring their network states and evaluate the those using extended AHP method. In order to verify the usefulness of our proposed system, a prototype system is constructed and its performance is evaluated.
    No preview · Conference Paper · May 2014
  • Saneatsu Arimura · Yoshitaka Shibata · Yuji Ohashi · Noriki Uchida
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    ABSTRACT: There were serious damages in the northern part of Japan by the East Japan Great Earthquake on March 11, 2011. In order to quickly find and rescue the missing people and understand the disaster state in the damaged areas, it is required to widely monitor and quickly collect the information and images with disaster areas just after disaster. However, because of luck of power supply and communication network failure, it is very difficult to monitor the disaster area and transmit the image information to the headquarters. In this paper, we introduce a wireless ballooned monitoring system which is organized by high resolution omni-directional camera and wireless LAN to take images from the sky and sends them to the relay station on the ground. Thus, the images of wide areas in the disaster place ware monitored to quickly make decision for rescue on the disaster headquarter.
    No preview · Conference Paper · May 2014
  • Go Hirakawa · Phyu Phyu Kywe · Kenta Ito · Yoshitaka Shibata
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    ABSTRACT: In this paper, we introduce a disaster area information gathering and distribution system SODiCS, which is expected to be an effective disaster prevention system in disaster-prone Japan. Moreover, we introduce automotive sensor data platform COMOSE, which can easily handle multiple sensor nodes. Subsequently, we declare functional requirements of SODiCS system and show that it is possible to implement SODiCS system of over COMOSE platform.
    No preview · Conference Paper · May 2014
  • Noriki Uchida · Noritaka Kawamura · Kazuo Takahata · Yoshitaka Shibata
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    ABSTRACT: In case of local areas, there are possibilities to isolate from other areas after earthquakes. Besides, the network diversity between urban and local area might cause the future problems of health or public services by information networks. The DTN (Delay Tolerant Networks) is considered to be one of the effective methods, and there are previous researches to improve the DTN routings. However, the current rapid developments of mobile devices such as data storages or broadband wireless networks have made the efficiency different as the previous researches. Therefore, we propose the Enhanced Media Coordinate System for DTN to the architecture in order to provide the Data Triage, Node Selection based on its Territory, and Dynamic FEC (Forward Error Correction). In this paper, the proposed Dynamic FEC with population estimation is especially explained, and the results of the computational simulation by the GIS map of a Japanese coastal town are reported. Then, the results are discussed for the future studies of DTN for Disaster Information Network System in local areas.
    No preview · Conference Paper · May 2014
  • Yoshitaka Shibata · Noriki Uchida · Norio Shiratori
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    ABSTRACT: Recently serious natural disasters such as earthquakes, tsunamis, typhoons, and hurricanes have occurred at many places around the world. The East Japan Great Earthquake on March 11, 2011 had more than 19,000 victims and destroyed a huge number of houses, buildings, loads, and seaports over the wide area of Northern Japan. Information networks and systems and electric power lines were also severely damaged by the great tsunami. Functions such as the highly developed information society, and residents?? safety and trust were completely lost. Thus, through the lessons from this great earthquake, a more robust and resilient information network has become one of the significant subjects. In this article, our information network recovery activity in the aftermath of the East Japan Great Earthquake is described. Then the problems of current information network systems are analyzed to improve our disaster information network and system through our network recovery activity. Finally we suggest the systems and functions required for future large-scale disasters.
    No preview · Article · Mar 2014 · IEEE Communications Magazine
  • Noriki Uchida · Noritaka Kawamura · Goshi Sato · Yoshitaka Shibata
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    ABSTRACT: Although two years have already passed after the East Japan Great Earthquake in 2011, outstanding topics such as having a resilient network for disasters still remain. The rural areas are considered more likely isolated from others because of limited transportation and network resources compared with the urban areas. In this paper, we introduce the resilient network with cognitive wireless network (CWN) based on delay tolerant networking (DTN) for disaster information system (DIS) in rural areas. In the system, a proper wireless link for each mobile is selected by comparing network parameters such as throughput, jitter, and latency, and transmits data sent by the DTN routing protocol including the Epidemic, Spray and Wait, MaxProp, and PROPHET. The simulation is held according to the GIS map, and the results are ready for discussion for future studies of DTN usages for DIS in rural areas.
    No preview · Article · Jan 2014 · International Journal of Adaptive and Innovative Systems
  • Source
    Noriki Uchida · Norihiro Kawamura · Goshi Sato · Yoshitaka Shibata
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    ABSTRACT: When Disaster Information Network System is considered in local areas that were heavy damaged by the East Japan Great Earthquake in 2011, the resiliency of the network system is one of significant subjects for the restoration of the areas. DTN (Delay Tolerant Network) has been focused for the effective methods for such inoperable network circumstances. However, when DTN is applied for the local areas, there are some problems such as message delivery rate and latency because there are fewer roads, cars, and pedestrians than in urban areas. In this paper, we propose the Enhanced Media Coordinate System for its architecture, and Data Triage method by emergent user policies is introduced to improve the QoS in Disaster Information Network System in local areas. In the proposed method, every message is tagged with the priority levels by data types with considering emergent user policies, and the high priority messages are firstly duplicated to transmittable nodes. Then, the experimental results by the GIS map of a Japanese coastal town and the future studies are discussed.
    Preview · Article · Jan 2014 · Mobile Information Systems
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    ABSTRACT: In this paper, we propose the safety confirmation system. When a large-scale disaster occurs, evacuation centers are set up in each local government. We are building the safety confirmation system which gathers refugees information to the disaster countermeasures headquarters, when a large-scale disaster occurs. In this system, suitable evacuation center operations are supported by the disaster countermeasures headquarters consolidate the refugees information on each evacuation centers. Moreover, we aim at the system development as a suitable information communication tool to the relatives and acquaintances of remote places by publicizing the refugees information on each evacuation centers from each local government's website.
    No preview · Conference Paper · Oct 2013
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    ABSTRACT: After the East Japan Great Earthquake in 2011, a robust network communication has been one of significant subjects for the study of Disaster Information System. Then, DTN (Delay Tolerant Network) has been focused for the effective methods for such inoperable network circumstances. However, when DTN is applied for the local areas, there are some problems such as message delivery rate and latency because there are fewer roads, cars, and pedestrians than in urban areas. Therefore, we propose the Enhanced Media Coordinate System for DTN to the architecture in order to provide the Data Triage, Node Selection based on its Territory, and Dynamic FEC (Forward Error Correction). In this paper, the proposed Data Triage Methods that provide the data priority by the user policy and the application type is especially explained, and the results of the computational simulation by the GIS map of a Japanese coastal town is reported. Then, the results are discussed for the future studies of DTN for Disaster Information Network System in local areas.
    No preview · Conference Paper · Oct 2013
  • Yasuo Ebara · Satoshi Noda · Akira Sakuraba · Yoshitaka Shibata
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    ABSTRACT: In order to realize high-realistic sensation tele-communication over wide-area network, we consider that non-verbal communication play an important role, and displaying the existence of participant by high-quality video streaming on large-scale screen system in each remote site is effective. However, the display specification of these systems such as commercial projector and wide-area monitor is low-resolution, and displaying of real video streaming with sufficient quality is difficult. Moreover, displaying video streaming with realistic high-resolution is serious, because there is a limit in the display resolution of video image captured by a single camera. We have constructed the tele-communication environment to display ultra resolution video streaming by multi-transmitting each video image which captured by four cameras with tiled display wall which is a technology to display various high-resolution contents by configuring the large-scale display with two or more LCD panels. In this paper, we have conducted an experiment on ultra-resolution video transmission between remote sites via wide-area network by using this tiled display wall environment in order to examine the feasibility of high-realistic sensation tele-communication, and have reported the experimental results.
    No preview · Conference Paper · Sep 2013
  • Goshi Sato · Noriki Uchida · Yoshitaka Shibata
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    ABSTRACT: Since the conventional communication means are severely damaged and cannot be functioned at the occurrence of disaster, more robust and redundant information infrastructure has to be constructed to prepare the estimated large disasters. In this paper, we reported the implementations and evaluation of the resilient network system, which is based on cognitive wireless network framework in order to provide a robust and quick recovery from the damages. In the proposed methods, we introduced autonomous wireless link and path changes by the network environment and user policy changes, and the prototype is used for the evaluation of the proposed methods.
    No preview · Conference Paper · Jul 2013
  • Goshi Sato · Koji Hashimoto · Noriki Uchida · Yoshitaka Shibata
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    ABSTRACT: In this paper, we introduce a network link selection method for disaster oriented mobile network based on Software Defined Network framework using based on dynamic network reconfiguration method to improve the connectivity. Our network system is consisted of multiple mobile routers based on currently available wireless LANs. Those wireless networks are interconnected by OpenFlow Switch and their links are managed by OpenFlow Controller. The proper communication links can be selected based on the required network characteristic, such as electro-magnetic field strength, throughput, latency, packet loss rate and communication distance. In this paper, we designed and implemented a disaster information wireless network with currently available different wireless LANs and constructed a prototype system to evaluate the performance of the mobile router.
    No preview · Conference Paper · Jul 2013
  • Noriki Uchida · Noritaka Kawamura · Yoshitaka Shibata
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    ABSTRACT: It has been already one year and ten months since the East Japan Great Earthquake in 2011. Even now, there are still so many problems including political problems for the reconstruction from the earthquake, but some newly disaster related researches are also being carried out for the reconstruction of the damaged cities. DTN (Delay Tolerant Network) is supposed to be one of the effective methods to transmit even under poor network conditions. However, when DTN is applied to local areas such as Taro in Japan, DTN might not work effectively because there are fewer roads, cars, and pedestrians than in urban areas. Therefore, this paper deals with DTN with (CWN) Cognitive Wireless Network consists of multiple wireless interfaces as proposed by a Disaster Information Network System in order to set up in local areas. Then, considering the actual usage of DTN in local areas, the simulation is held according to the map of Taro in Japan, the severely damaged town in the East Japan Great Earthquake. The proposal methods are simulated by the Epidemic Routing and Spray and Wait Routing in comparison with single IEEE802.11b/g and amateur radio. Then, the results are discussed for the future studies of DTN usages for Disaster Information Network System in local areas.
    No preview · Conference Paper · Jul 2013