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Fukushima Y.,Okayama University | Yokohira T.,Nagoya University | Murase T.,Okayama University | Suda T.,University Netgroup Inc
2016 International Conference on Information and Communication Technology Convergence, ICTC 2016 | Year: 2016

The server migration service (SMS) is an optional service that improves communication QoS of the IaaS cloud service. In the SMS, small-scale data centers (micro data centers) called work places (WPs) are deployed at various locations in the network. In the SMS, a network application (a NW-App) consists of one or more server-side processes of the application (servers) and one or more client-side processes of the application (clients). In the SMS, servers migrate among WPs in order to improve communication QoS between the servers and their clients, unlike in the IaaS cloud service where locations of the servers are always fixed at a data center in the network. In our previous study, we developed an integer programming model and solved it to determine when and to which WPs servers should migrate in the SMS in order to minimize the financial penalty, i.e., SMS provider's financial loss due to degradation of the communication QoS. In this paper, we consider the electricity power cost, an important component of the operational cost of the SMS, in addition to the financial penalty considered in our previous study, in determining when and to which WPs servers should migrate in the SMS. In this paper, we define the operational cost of the SMS as the sum of the financial penalty and electricity power cost and consider a power-Aware server location decision problem in order to minimize the operational cost of the SMS. We formulate the problem as a mixed-integer programming model and solve the model numerically. Numerical examples show that our mixed-integer programming model optimally determines the locations of the servers and decreases the operational cost by up to 15.5% compared to our previous integer programming model, where the power cost was not considered. © 2016 IEEE.


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 | Year: 2012

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.


Honjo M.,KDDI | Hasegawa T.,KDDI | 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 | Year: 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.


Nakano T.,Osaka University | Suda T.,University Netgroup Inc | Okaie Y.,Osaka University | Moore M.J.,Osaka University | Vasilakos A.V.,University of Western Macedonia
IEEE Transactions on Nanobioscience | Year: 2014

Molecular communication is an emerging communication paradigm for biological nanomachines. It allows biological nanomachines to communicate through exchanging molecules in an aqueous environment and to perform collaborative tasks through integrating functionalities of individual biological nanomachines. This paper develops the layered architecture of molecular communication and describes research issues that molecular communication faces at each layer of the architecture. Specifically, this paper applies a layered architecture approach, traditionally used in communication networks, to molecular communication, decomposes complex molecular communication functionality into a set of manageable layers, identifies basic functionalities of each layer, and develops a descriptive model consisting of key components of the layer for each layer. This paper also discusses open research issues that need to be addressed at each layer. In addition, this paper provides an example design of targeted drug delivery, a nanomedical application, to illustrate how the layered architecture helps design an application of molecular communication. The primary contribution of this paper is to provide an in-depth architectural view of molecular communication. Establishing a layered architecture of molecular communication helps organize various research issues and design concerns into layers that are relatively independent of each other, and thus accelerates research in each layer and facilitates the design and development of applications of molecular communication. © 2002-2011 IEEE.


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 | Year: 2012

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.


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 | Year: 2014

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.


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 | Year: 2012

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.


Nakano T.,Osaka University | Suda T.,University Netgroup Inc | Okaie Y.,Osaka University | Moore M.J.,University of California at San Diego
Proceedings - 2016 IEEE 10th International Conference on Semantic Computing, ICSC 2016 | Year: 2016

This paper considers Ask.fm, a social networking site where users create profiles and can send each other questions, and analyses aggressive user behavior that may potentially lead to cyber-bullying incidents. We hypothesize that anonymity is a primary cause of such aggressive user behavior and examine how anonymous and non-anonymous users behave in social networking. We collected data from Ask.fm and analyzed questions posted by anonymous and non-anonymous users and answers posted by non-anonymous users. Analysis of the collected data shows that anonymous users exhibit more aggressive behavior than non-anonymous users. Analysis also shows that users become more aggressive in answering aggressive anonymous questions than aggressive non-anonymous questions. © 2016 IEEE.


Nakano T.,Osaka University | Moore M.J.,Osaka University | Okaie Y.,Osaka University | Enomoto A.,University of California at Irvine | Suda T.,University Netgroup Inc
2013 IEEE International Conference on Communications Workshops, ICC 2013 | Year: 2013

This paper describes an architectural design of molecular communication for biological nanomachines to perform cooperative drug delivery, and discusses three key challenges: targeting biological nanomachines to a target site where diseased cells may exist, diagnosis by biological nanomachines to monitor the target site and identify a potential threat and therapy by biological nanomachines to remove the threat. This paper presents an initial design of the molecular communication architecture for cooperative drug delivery and discusses how the molecular communication architecture may address these design challenges. © 2013 IEEE.

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