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Moore M.J.,Osaka University | Nakano T.,Osaka University | Enomoto A.,University of California at Irvine | Suda T.,University Netgroup Inc
IEEE Transactions on Signal Processing

Systems of bionanomachines may benefit future applications which require interaction with biological systems at the nano- to microscale. Molecular communication is a suitable communication mechanism for autonomous bionanomachines which are limited in size and capability and for interfacing with biological systems. In molecular communication, a bionanomachine transmits information to a receiver bionanomachine by modulating the concentration of molecules in the environment. One promising direction for molecular communication is for a bionanomachine to measure the distance to another bionanomachine in order to perform location-based functionality or to adapt communications using the measured distance. In this paper, a bionanomachine measures the distance to another bionanomachine by requesting the other bionanomachine to transmit a feedback signal of many molecules transmitted over a short time interval (i.e., a single spike of molecules). Upon receiving the feedback signal, the bionanomachine which requested the feedback signal then estimates distance by measuring the Round Trip Time (RTT) or Signal Attenuation (SA) of the received feedback signal. The propagation of molecules and the receiving of molecules are modeled to investigate how distance impacts measured RTT and SA. Simulations are performed to measure the accuracy of the distance measurement, the time required to measure distance, and how the number of molecules transmitted affects accuracy. © 2012 IEEE. Source

Honjo M.,KDDI R and D Laboratories Inc. | Hasegawa T.,KDDI R and D Laboratories Inc. | Suda T.,University Netgroup Inc | Mishima K.,Chubu University | Yoshida T.,Nagoya University
Proceedings - 2011 IEEE International Conference on Privacy, Security, Risk and Trust and IEEE International Conference on Social Computing, PASSAT/SocialCom 2011

In this paper, the authors consider school bullying using digital communication media (such as cell phones, short messaging, emails, blogs, SNS, and BBS) and create a framework whose goal is to help teachers identify whether school bullying is taking place among students. The framework proposed in this paper models interactions among students as a relationship network (referred to as a "human relationship network"), constructs a human relationship network from usage statistics of digital communication media, and identifies whether unique structural features exist in a human relationship network that may indicate bullying among students. The proposed framework is designed based on two hypotheses. First, a human relationship network can be constructed with some degree of accuracy from usage statistics of digital communication media. Second, risk factors for school bullying impose distinct structural features in a human relationship network. This paper presents the initial effort to empirically verify the hypotheses to lay the foundations for further design of the proposed framework. © 2011 IEEE. Source

Moore M.J.,Osaka University | Nakano T.,Osaka University | Enomoto A.,University of California at Irvine | Suda T.,University Netgroup Inc
Computers in Human Behavior

Cyberbullying is a growing concern in online communications. Cyberbullying has negative impacts such as distress or suicide of a victim. One common type of cyberbullying attack utilizes aggressive forum posts to insult or threaten a victim. Automated tools to classify cyberbullying may aid in avoiding or reducing the negative impacts of cyberbullying. One approach to produce an automated tool is to identify features of forum posts which may be indicators of cyberbullying. One feature of a forum post is the role of the author of the forum post, such as a bully, victim, or defender. Another feature is whether the forum post insults or threatens an individual (e.g., contains insults directed at a victim). Attackers may use aggressive forum posts to attack someone and defenders may use aggressive forum posts to retaliate against attackers. Another feature is whether the communication is anonymous (e.g., sending forum posts with no identifier) since cyberbullies utilize anonymity to reduce the ability of the victim to defend themselves and to shield the cyberbully from social consequences. In this paper, forum posts were labeled in an online forum for these features. Text matching techniques had some success in identifying aggressiveness forum posts including both attacks and defends. Anonymity of forum posts (i.e., forum posts with no identifier) was identified as a criterion to distinguish attackers (more anonymous relative to non-aggressive communications) from defenders (less anonymous relative to non-aggressive communications). © 2012 Elsevier Ltd. All rights reserved. Source

Yamanaka A.,Okayama University | Fukushima Y.,Okayama University | Yokohira T.,Okayama University | Murase T.,NEC Corp | Suda T.,University Netgroup Inc
Proceedings of the 7th International Conference on Future Internet Technologies, CFI'12

Using network virtualization technologies for network applications (NW-Apps) consisting of server and clients, we can implement a server migration service where there are many server running environments (working places: WPs) inside a network and servers onWPs can migrate to otherWPs when communication QoSs in some NW-Apps fall off. Because server size is large, the traffic for server migration causes QoS degradation of its background traffic. Thus, it is important to decrease the degree (network impact) of the QoS degradation. In this paper, we propose three destination selection algorithms, MIA (Minimum Impact Algorithm), MRA (Maximum Remaining space Algorithm) and MCA (Maximum Covering Algorithm) that try to decrease the impact while increasing the number of NW-Apps' clients whose SLA (service level agreement) are satisfied. When a server migration is triggered, MIA, MRA and MCA move the server in the WP with the minimum impact, the WP with the maximum remaining space for servers and the WP with the maximum coverage, which is the number of routers under which the corresponding clients can communicate with the server while satisfying the SLA, respectively. Numerical examples show that when the number of accommodatable servers in full-cover WP (a full-cover WP is such WP that communicates with an arbitrary client while satisfying the SLA) is small or there is no full-cover WP, MIA outperforms the others, otherwise MCA outperforms the others. Copyright © 2012 by the Association for Computing Machinery, Inc. Source

Nakano T.,Osaka University | Kobayashi S.,Japan National Institute of Information and Communications Technology | Suda T.,University Netgroup Inc | Okaie Y.,Osaka University | And 2 more authors.
IEEE Journal on Selected Areas in Communications

In molecular communication, a group of biological nanomachines communicates through exchanging molecules and collectively performs application dependent tasks. An open research issue in molecular communication is to establish interfaces to interconnect the molecular communication environment (e.g., inside the human body) and its external environment (e.g., outside the human body). Such interfaces allow conventional devices in the external environment to control the location and timing of molecular communication processes in the molecular communication environment and expand the capability of molecular communication. In this paper, we first describe an architecture of externally controllable molecular communication and introduce two types of interfaces for biological nanomachines; bio-nanomachine to bio-nanomachine interfaces (BNIs) for bio-nanomachines to interact with other biological nanomachines in the molecular communication environment, and inmessaging and outmessaging interfaces (IMIs and OMIs) for bio-nanomachines to interact with devices in the external environment. We then describe a proof-of- concept design and wet laboratory implementation of the IMI and OMI, using biological cells. We further demonstrate, through mathematical modeling and numerical experiments, how an architecture of externally controllable molecular communication with BNIs and IMIs/OMIs may apply to pattern formation, a promising nanomedical application of molecular communication. © 2014 IEEE. Source

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