Fukushima, Japan
Fukushima, Japan

The University of Aizu in Aizu-Wakamatsu, Japan, is the first university dedicated to computer science engineering in Japan. It has about 1,100 students enrolled in its undergraduate and graduate programs. The university advocates "advancement of knowledge for humanity" and carries out significant research in computer science. Wikipedia.

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Yen N.Y.,University of Aizu | Shih T.K.,National Central University | Jin Q.,Waseda University
ACM Transactions on Intelligent Systems and Technology | Year: 2013

Sharing resources and information on the Internet has become an important activity for education. In distance learning, instructors can benefit from resources, also known as Learning Objects (LOs), to create plenteous materials for specific learning purposes. Our repository (called the MINE Registry) has been developed for storing and sharing learning objects, around 22,000 in total, in the past few years. To enhance reusability, one significant concept named Reusability Tree was implemented to trace the process of changes. Also, weighting and ranking metrics have been proposed to enhance the searchability in the repository. Following the successful implementation, this study goes further to investigate the relationships between LOs from a perspective of social networks. The LONET (Learning Object Network), as an extension of Reusability Tree, is newly proposed and constructed to clarify the vague reuse scenario in the past, and to summarize collaborative intelligence through past interactive usage experiences.We define a social structure in our repository based on past usage experiences from instructors, by proposing a set of metrics to evaluate the interdependency such as prerequisites and references. The structure identifies usage experiences and can be graphed in terms of implicit and explicit relations among learning objects. As a practical contribution, an adaptive algorithm is proposed to mine the social structure in our repository. The algorithm generates adaptive routes, based on past usage experiences, by computing possible interactive input, such as search criteria and feedback from instructors, and assists them in generating specific lectures. © 2013 ACM.


TOKYO, Nov 2, 2016 /PRNewswire/ -- Soramitsu Co., Ltd. (Co-CEOs: Makoto Takemiya, Ryu Okada; hereafter, Soramitsu) developed an open source distributed ledger (i.e., blockchain [1]) platform, Iroha, and submitted it to the Linux Foundation's Hyperledger Project as an incubation sub-project. Iroha was accepted into incubation status and will join IBM's Fabric and Intel's Sawtooth Lake as the third distributed ledger project with incubation status. Iroha is a new distributed ledger platform that was developed from scratch and proposed to the Hyperledger Project by Soramitsu, NTT Data, and Israeli startup Colu, among others, on September 26th, 2016, in Geneva, Switzerland. On October 13, 2016, Iroha was officially accepted into incubation status. Iroha aims to provide a secure and decentralized data management platform for financial institutions, as well as many other fields, such as healthcare and logistics. Using the custom "Sumeragi" consensus algorithm, Iroha aims to provide consistent transaction finality within 2 seconds, making the platform useful for many real-world scenarios. To provide high throughput scaling to thousands of transactions per second, Iroha uses UDP multicast and C++ for data processing. To explore use cases and work to increase the viability of the Iroha platform, Sompo Holdings Inc. is working with Soramitsu to create derivatives on top of the distributed ledger. The University of Tokyo, the University of Aizu, and the Center for Global Communications (GLOCOM) of the International University of Japan, are also working with Soramitsu to study the economics of local currencies and their effects on regional development. Joint research in the area around Aizu, in Fukushima Prefecture, Japan, will include experiments using local currencies running on Iroha. In addition, with Rakuten Securities, Inc., Soramitsu has announced that they are working together to develop a KYC [2] system using blockchain technology. Mizuho Information & Research Institute, Inc., is also exploring the use of Iroha. Soramitsu is committed to the development of blockchain systems that can contribute to society by providing safe and secure data management. Partners who want to contribute to Iroha and also work with Soramitsu on creating services, especially a digital identity KYC service for financial institutions, are invited to contact Soramitsu. Iroha is open source and anyone can contribute to it at http://github.com/hyperledger/iroha. -- Simple architecture, easy to understand and to develop for -- Distributed ledger technology and smart contract platform -- New Byzantine Fault Tolerant consensus algorithm, called Sumeragi -- Java-based smart contracts -- Simple issuance and transfer of digital assets, such as currencies and points -- Mobile and web application development platforms Expected use-cases for Iroha (among others) -- Settlement -- Contract management -- Securities clearing -- Development of financial products such as insurance -- Supply chain management -- Smart grid -- Trade finance -- KYC [2] -- Notary and time stamp services -- Sharing economy -- Healthcare -- IoT About the use of trademarks All company, product names, and trademarks, are the property of their respective owners. Soramitsu is a Japanese startup founded in February of 2016, focusing on blockchain and distributed ledger technology. Currently, Soramitsu is developing a platform for managing digital identities. Since identity management is required for many disparate services, building a digital identity platform on blockchain technology is an important way to manage identity for applications involving many different players. Soramitsu is a member of the Linux Foundation's Hyperledger Project. The Hyperledger Project aims to create global standards for blockchain and distribution ledger technology, with the aim of providing practical solutions for businesses and meeting the needs of society. To view the original version on PR Newswire, visit:http://www.prnewswire.com/news-releases/soramitsus-iroha-distributed-ledger-platform-accepted-by-the-linux-foundations-hyperledger-project-as-the-third-platform-with-incubation-status-300355032.html


Hagino K.,Tohoku University | Sagawa H.,University of Aizu
Physical Review C - Nuclear Physics | Year: 2011

We investigate the spatial extension of weakly bound Ne and C isotopes by taking into account the pairing correlation with the Hartree-Fock-Bogoliubov (HFB) method and a three-body model, respectively. We show that the odd-even staggering in the reaction cross sections of 30,31,32Ne and 14,15,16C are successfully reproduced, and thus the staggering can be attributed to the pairing anti-halo effect. A correlation between a one-neutron separation energy and the anti-halo effect is demonstrated for s and p waves using the HFB wave functions. © 2011 American Physical Society.


Moller P.,Los Alamos National Laboratory | Myers W.D.,Los Alamos National Laboratory | Sagawa H.,University of Aizu | Yoshida S.,Hosei University
Physical Review Letters | Year: 2012

The parameters in the macroscopic droplet part of the finite-range droplet model (FRDM) are related to the properties of the equation of state. In the FRDM (1992) version, the optimization of the model parameters was not sufficiently sensitive to variations of the compressibility constant K and the density-symmetry constant L to allow their determination. In the new, more accurate FRDM-2011a adjustment of the model constants to new and more accurate experimental masses allows the determination of L together with the symmetry-energy constant J. The optimization is still not sensitive to K which is therefore fixed at K=240MeV. Our results are J=32.5±0.5MeV and L=70±15MeV and a considerably improved mass-model accuracy σ=0.5700MeV, with respect to the 2003 Atomic Mass Evaluation (AME2003) for FRDM-2011a, compared to σ=0.669MeV for FRDM (1992). © 2012 American Physical Society.


Schwende I.,University of Aizu | Pham T.D.,University of Aizu
Briefings in Bioinformatics | Year: 2014

With the massive production of genomic and proteomic data, the number of available biological sequences in databases has reached a level that is not feasible anymore for exact alignments even when just a fraction of all sequences is used. To overcome this inevitable time complexity, ultrafast alignment-free methods are studied. Within the past two decades, a broad variety of nonalignment methods have been proposed including dissimilarity measures on classical representations of sequences like k-words or Markov models. Furthermore, articles were published that describe distance measures on alternative representations such as compression complexity, spectral time series or chaos game representation. However, alignments are still the standard method for real world applications in biological sequence analysis, and the time efficient alignment-free approaches are usually applied in cases when the accustomed algorithms turn out to fail or be too inconvenient. © The Author 2013. Published by Oxford University Press.


Dang N.T.,University of Aizu | Pham A.T.,University of Aizu
Optics Express | Year: 2012

Previous studies show that, compared to on-off keying (OOK) signaling, pulse-position modulation (PPM) is favorable in FSO/CDMA systems thanks to its energy efficiency and simple detection. Nevertheless, when the system bit rate increases and the transmission distance is far, the FSO/CDMA systems using PPM signaling critically suffer from the impact of pulse broadening caused by dispersion, especially when the modulation level is high. In this paper, we therefore propose to use multi-wavelength PPM (MWPPM) signaling to overcome the limitation of PPM. To further improve the system performance, avalanche photodiode (APD) is also used. The performance of the proposed system is theoretically analyzed using a realistic model of Gaussian pulse propagation. To model the impact of intensity fluctuation caused by the atmospheric turbulence, the log-normal channel is used. We find that, by using MWPPM, the effects of both intensity fluctuation and pulse broadening are mitigated, the BER is therefore significantly improved. Additionally, we quantitatively show that the system performance is further improved by using APD, especially when the average APD gain is chosen properly. © 2012 Optical Society of America.


Pham T.D.,University of Aizu
Information Sciences | Year: 2014

Methodological design issues in pattern recognition are of particular interests to many scientific disciplines ranging from life science to engineering. Practical applications of pattern or object recognition methods are numerous but still encountering many problems including the inherent difficulty in computerized feature extraction and classification. This paper proposes a strategy for object recognition resembling the active template matching strategy in chickens. Experimental results on several databases suggest that using the active vision processing can improve classification rates implemented with various classifiers. © 2014 Elsevier Inc. All rights reserved.


Yamakami T.,University of Aizu
Theoretical Computer Science | Year: 2011

We discuss the computational complexity of context-free languages, concentrating on two well-known structural properties - immunity and pseudorandomness. An infinite language is REG-immune (resp., CFL-immune) if it contains no infinite subset that is a regular (resp., context-free) language. We prove that (i) there is a context-free REG-immune language outside REG n and (ii) there is a REG-bi-immune language that can / be computed deterministically using logarithmic space. We also show that (iii) there is a CFL-simple set, where a CFL-simple language is an infinite context-free language whose complement is CFL-immune. Similar to the REG-immunity, a REG-primeimmune language has nopolynomially dense subsets that are also regular. We further prove that (iv) there is a context-free language that is REG/n-bi-primeimmune. Concerning pseudorandomness of context-free languages, we show that (v) CFL contains REG/n-pseudorandom languages. Finally, we prove that (vi) against REG/n, there exists an almost 1-1 pseudorandom generator computable in nondeterministic pushdown automata equipped with a write-only output tape and (vii) against REG, there is no almost 1-1 weakly pseudorandom generator computable deterministically in linear time by a single-tape Turing machine. © 2011 Elsevier B.V. All rights reserved.


Madaan A.,University of Aizu
Proceedings of the VLDB Endowment | Year: 2013

Vast amount of medical information is increasingly available on the Web. As a result, seeking medical information through queries is gaining importance in the medical domain. The existing keyword-based search engines such as Google, Yahoo fail to suffice the needs of the health-care workers (who are well-versed with the domain knowledge required for querying) using these they often face results which are irrelevant and not useful for their tasks. In this paper, we present the need and the challenges for a user-level, domain-specific query language for the specialized document repositories of the medical domain. This topic has not been sufficiently addressed by the existing approaches including SQL-like query languages or generalpurpose keyword-based search engines and document-level indexing based search. We aim to bridge the gap between information needs of the skilled/semi-skilled domain users and the query capability provided by the query language. Overcoming such a challenge can facilitate effective use of large volume of information on the Web (and in the electronic health records (EHRs)repositories). © 2013 VLDB Endowment.


Lubashevsky I.A.,University of Aizu
European Physical Journal B | Year: 2011

A continuous Markovian model for truncated Lévy flights is proposed. It generalizes the approach developed previously by Lubashevsky et al. [Phys. Rev. E 79, 011110 (2009); Phys. Rev. E 80, 031148 (2009), Eur. Phys. J. B 78, 207 (2010) and allows for nonlinear friction in wandering particle motion as well as saturation of the noise intensity depending on the particle velocity. Both the effects have own reason to be considered and, as shown in the paper, individually give rise to a cutoff in the generated random walks meeting the Lévy type statistics on intermediate scales. The nonlinear Langevin equation governing the particle motion was solved numerically using an order 1.5 strong stochastic Runge-Kutta method. The obtained numerical data were employed to analyze the statistics of the particle displacement during a given time interval, namely, to calculate the geometric mean of this random variable and to construct its distribution function. It is demonstrated that the time dependence of the geometric mean comprises three fragments following one another as the time scale increases that can be categorized as the ballistic regime, the Lévy type regime (superballistic, quasiballistic, or superdiffusive one), and the standard motion of Brownian particles. For the intermediate Lévy type part the distribution of the particle displacement is found to be of the generalized Cauchy form with cutoff. Besides, the properties of the random walks at hand are shown to be determined mainly by a certain ratio of the friction coefficient and the noise intensity rather than their characteristics individually. © 2011 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.

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