Time filter

Source Type

Chiba, Japan

Tokyo University of Information science is a private university in Wakaba Ward of the city of Chiba, Chiba Prefecture, Japan. The university was established in 1988 by the School corporation Tokyo University of Agriculture. The university consists of four departments: Information System, Environmental Information, Business & Information, and Media & Cultural Studies. To follow the rapid period changing and better contribution for our society, we always make our best on student education of their creativity and excellent personality. Wikipedia.

Yoon M.-G.,Gangneung - Wonju National University | Tsumura K.,Tokyo University of Information Sciences
Automatica | Year: 2011

This paper presents explicit forms of transfer functions for a class of cyclic consensus systems with different kinds of network topologies; directed, undirected and different numbers of reference agents. Each agent of consensus systems is assumed to satisfy a scalar integrator dynamics which is driven by a common consensus protocol and an independent exogenous input. It is shown that every single-input single-output (SISO) transfer function between the exogenous input of one agent and the state of another generally different agent, is always minimum phase. In addition, the poles and zeros, system degrees and relative degrees of those SISO transfer functions are specified. These results are interpreted in relation to the controllability and closed loop performance of a networked system with one leader agent. Furthermore, our transfer function representations are applied to an investigation of stability margins for a closed loop cyclic consensus system. © 2011 Elsevier Ltd. All rights reserved. Source

Soma T.,Tokyo University of Information Sciences
IEEE Transactions on Information Theory | Year: 2016

We provide a deterministic polynomial time algorithm for multicasting in a linear deterministic relay network and a wireless communication framework proposed by Avestimehr et al. The running time of our algorithm is faster than existing ones and matches the current best complexity of unicast computations for each sink. Our approach is based on the polylinking flow model of Goemans et al. and the mixed matrix completion technique of Harvey et al. © 2015 IEEE. Source

Nishimura A.,Tokyo University of Information Sciences
International Journal of Innovative Computing, Information and Control | Year: 2010

A technique for audio data hiding by using subband amplitude modulation was evaluated by computer simulations in terms of robustness with respect to the cumulative effects of reverberations, background noise, and encoding and decoding with a speech codec. Speech signals from 22 speakers and signals from 100 pieces of music were used as the host audio data. Computer simulations revealed that speech and music signals with background noise and reverberations were able to transmit at least 80% of the embedded data at 8 bps after encoding and decoding using the Adaptive Multi-Rate (AMR) speech codec at a bitrate of 12.2 kbps. In actual measurements in a reverberant room using a cell phone terminal, data hidden in a 12.2-kbps AMR recording having a signal-to-noise ratio of 20 dB was detected at a mean bit error rate of 15 %. The sound quality degradation induced by data hiding was objectively measured using the perceptual evaluation of speech quality (PESQ) and perceptual evaluation of audio quality (PEAQ) algorithms. The average PESQ score of the speech signals approximately corresponded to a subjective evaluation of 'fair', while the average PEAQ score of the music signals corresponded to a somewhat lower subjective evaluation of 'slightly annoying'. ©2010 ISSN 1349-4198. Source

Gozolchiani A.,Bar - Ilan University | Havlin S.,Bar - Ilan University | Yamasaki K.,Tokyo University of Information Sciences
Physical Review Letters | Year: 2011

We construct and analyze a climate network which represents the interdependent structure of the climate in different geographical zones and find that the network responds in a unique way to El Niño events. Analyzing the dynamics of the climate network shows that when El Niño events begin, the El Niño basin partially loses its influence on its surroundings. After typically three months, this influence is restored while the basin loses almost all dependence on its surroundings and becomes autonomous. The formation of an autonomous basin is the missing link to understand the seemingly contradicting phenomena of the afore-noticed weakening of the interdependencies in the climate network during El Niño and the known impact of the anomalies inside the El Niño basin on the global climate system. © 2011 American Physical Society. Source

Kobayashi N.,Tokyo University of Information Sciences
Journal of the ACM | Year: 2013

We propose a novel verification method for higher-order functional programs based on higher-order model checking, or more precisely, model checking of higher-order recursion schemes (recursion schemes, for short). The most distinguishing feature of our verification method for higher-order programs is that it is sound, complete, and automatic for the simply typed λ-calculus with recursion and finite base types, and for various program verification problems such as reachability, flow analysis, and resource usage verification. We first show that a variety of program verification problems can be reduced to model checking problems for recursion schemes, by transforming a program into a recursion scheme that generates a tree representing all the interesting possible event sequences of the program. We then develop a new type-based model-checking algorithm for recursion schemes and implement a prototype recursion scheme model checker. To our knowledge, this is the first implementation of a recursion scheme model checker. Experiments show that ourmodel checker is reasonably fast, despite the worst-case time complexity of recursion scheme model checking being hyperexponential in general. Altogether, the results provide a new, promising approach to verification of higher-order functional programs. © ACM 2013. Source

Discover hidden collaborations