 |
 |
Professor |
Associate Professor |
- Combinatorics and its applications;
- Spread spectrum communication;
- Signal processing;
- Image analysis for measurement;
- Enterprise Integration and Messaging Network:
- Security Management:
- Networks;
- GRID as a Service Oriented Architecture Based System;
- Security and management of computer system for e-Government;
- Blind source separation and independent component analysis, and their applications in acoustic signals and vital signs;
- Neural computing and brain-style signal processing;
- Optimization and machine learning;
- Time-reversal wave propagation in ergodic environment and its applications in acoustics, ultrasonics and telecommunications;
- Information theory and algorithmic complexity.
| The
research and education activities in the laboratory focus on the
theoretical foundations of computers and computations, including broad
applications in science and engineering. Our work covers algorithms and
computation, programming languages, discrete mathematics, and related
topics. |
| Areas of our research interest include
|
| Faculty
of the FCS laboratory teach Computer Literacy, Programming I,
Algorithms and Data Structures, Advanced Algorithms, Digital Signal
Processing, Introduction to Topology , SCCPs and other selective
courses. Students join faculty research and also develop their own
research themes. We participate in various research projects of JSPS,
NIFS, RIKEN etc. |
Refereed Journal Papers
| [sding-01:2007] |
S. Ding. Independent Component Analysis via Learning Updating Using
a Form of Orthonormal Transformation Based on the Diagonalization Principle.
International Journal of Innovative Computing, Information and Control,
3(5):1219-1235, 2007. |
| This paper presents a new type of algorithm for solving independent component analysis
(ICA) problems. Instead of being based on additive updating, which is used in
conventional algorithms, this new algorithm is based on an effective updating scheme
in which learning updating acts as a series of orthonormal matrix transformations
(i.e., power iteration). The criterion for the independence between outputs is based
on diagonality of a non-linearized covariance matrix, which is de ned by ICA outputs
and their non-linear mappings, and the Bussgang property. One attractive feature of
the algorithm is that it does not include any predetermined parameters, such as a
learning step size, as do gradient-based algorithms, which is especially expected for
ICA applications with unknown types of sources (but with the condition that at most
one source is Gaussian distributed). Another feature is that the convergence rate is
faster, even for very short observations. If the same ICA criteria are applied to the
proposed and gradient-based algorithms, the relationship between these algorithms is
quite similar to the relationship between the least-mean-square (LMS) algorithm and
the recursive least-square (RLS) algorithm in the batch mode for supervised adaptive
ltering. In this paper, we also analyze the algorithm mathematically to determine
why and how the algorithm works. We show that learning updating in the form of
matrix transformation permits nite-scale learning, and at the same time, maintains
the orthonormal property of the separation matrix. This is essentially different from
the case with gradient-based algorithms, which permits only a small-scale learning
that is controlled by the learning step size. We also analyze the relationship between
the new algorithm with other well-known algorithms, such as the Bussgang algorithm,
the non-linear principal component analysis (PCA), and the FastICA. |
|
| [takafumi-01:2007] |
Takafumi Hayashi. Zero-Correlation Zone Sequence Set Constructed
from a Perfect Sequence. IEICE Transaction of Fundamentals, E90-A(4):1107-
1111, 2007. |
| In this letter, we present a new approach to the construction of a novel ternary ZCZ
sequence set. |
|
| [takafumi-02:2007] |
Takafumi Hayashi. Zachman Framework for Realizing Information
Security of Local Governments. Journal of Japan Association for Social In-
formatics, 19(2):73-82, 2007. |
| In this paper, we present a scheme to esablish the Information Security of Local
Governments |
|
| [takafumi-03:2007] |
Takafumi Hayashi. An Integrated Sequence Construction of Binary Zero-Correlation Zone Sequences. IEICE Transaction of Fundamentals, E90-
A(10):2329-2335, 2007. |
| In this letter, we present a new integrated scheme to construct ZCZ sequence sets. |
|
| [takafumi-04:2007] |
Takafumi Hayashi and Shinya Matsufuji. Zero-Correlation Zone Sequence
Set Construction Using an Even-Perfect Sequence and an Odd-Perfect
Sequence. IEICE Transaction of Fundamentals, E90-A(9):1871-1875, 2007. |
| In this letter, we present a new approach to the construction of a new ZCZ sequences
using even-perfect sequence and odd-perfect sequence pair |
Referred Proceeding Papers
| [sding-02:2007] |
W. Liu and S. Ding. Multiuser Detections Based on Global Optimality
Necessary Conditions for Binary Quadratic Programming. In Proc. Interna-
tional Conference on Innovative Computing, Information and Control 2007
(ICICIC-07), pages 0-7695-2882-1/07. International Conference on Innovative
Computing, Information and Control 2007 (ICICIC-07), IEEE, IEEE,
2007. |
| In this paper, we present a novel multiuser detection method using the global optimality
necessary conditions for the binary quadratic programming. The proposed
method is separated into two steps. In step 1, based on the necessary conditions,
we give a rule that can decide the user information sequences directly. By this rule,
most of user information sequences can be decided with a low computational complexity.
Moreover, the decision results can be shown to be optimal. Therefore, we can
take advantage of these results in the original quadratic programming and obtain
a smaller-scaled binary quadratic programming problem for the undecided users in
step 1. Then in step 2, we can use some existing multiuser detection methods to solve
this reduced problem. The overall computation complexity of the proposed method
becomes less, and the BER is lower. |
|
| [sding-03:2007] |
W. Liu and S. Ding. An Efficient Method to Determine the Diagonal
Loading Factor for PAM Communication System. In Proc. 2007 IEEE Inter-
national Conference on Computer and Information Technology (CIT 2007),
pages 116-121. IEEE International Conference on Computer and Information
Technology (CIT 2007), IEEE, IEEE, 2007. |
| Minimum variance distortionless response (MVDR) beamformer are known to degrade
due to the effects of imprecise knowledge about the steering vector and nite
sample size. The diagonal loading method is a simple and effcient method that
improves the robustness of beamformers. However, determining an ideal diagonal
loading factor (DLF) is not a trivial problem, one that still has not been adequately
addressed. Although beamformers are widely used in radar, sonar, and many other applications, in this paper, we consider only the pulse-amplitude modulation (PAM)
digital communication applications. In this paper we take advantage of the binary
feature in PAM digital communication system and present an effective method to
determine the DLF. Since the binary feature is used, the new method does not require
extra assumptions as in other methods. Numerical experiments show that the
method improves the robustness of beamformers against mismatch caused by effects
related to imprecise knowledge of the steering vector and nite sample size. |
|
| [takafumi-05:2007] |
N. Harada, T. Hayashi, N. Hirata, H. Demura, and N. Asada. Recognition
Algorithm for Topographic Features. In Proc. of CIT 2007, pages
685-689. IEEE Computer Society, 2007. |
| We prposed a new algorithm to recognize topgraphic features |
|
| [takafumi-06:2007] |
Takafumi Hayashi, Hideyuki Fukuhara, Toshiaki Miayazaki, and
Senro Saito. A Messaging Network to Realize an SOA-Based System. In
Proc. of CIT 2007, pages 1038-1088. IEEE Computer Society, 2007. |
| We prposed a new schme to realize an SOA-Based System using messaging networking |
|
| [takafumi-07:2007] |
Takafumi Hayashi. Optimal Zero-Correlation Zone Sequence Set
Constructed from a Perfect Sequence. In Proc. of CIT 2007, pages 475-479.
IEEE Computer Society, 2007. |
| We prposed a new schme to generate ZCZ sequence set |
Unrefereed Papers
| [sding-04:2007] |
S. Ding, S. Matsuoka, and N. Sakurai. The Time-Reversal Acoustics
in Ergodic Cavity: Some Simulation and Experiment Results. In Technical
Report of IEICE, SP2007-23 (2007-06), pages 91-96. IEICE, 2007. |
| In this paper, we address the possibility of time-reversal acoustics (TRA) in a simulated
space, which is constructed by a stacked-neuron array (SNA). In the simulated
space, although it is highly discrete, the temporal focusing and the spatial focusing
can still occur as that in a realistic space. We numerically evaluated the performances
of these focusing effects. By this research, we aim to modeling of the space in arti cial
devices in the sense of acoustics and to providing clues for how the space is managed,
or modeled in the human auditory or in the brain. |
Grants
| [sding-05:2007] |
S. Ding. Blind source separation using sparse frame representation for multi source signals and its applications, 2008-2010. |
| This is supported as the project Scienti c Research C, No. 20500209, 2008 Grants-
In-Aid for Scienti c Research, Ministry of Education, Culture, Sports, Science and
Technology, Japan. |
|
| [takafumi-08:2007] |
Takafumi Hayashi. Study of of ternary sequence set having zerocorrelation zone for periodicand Aperiodic correlation functions, 2007-2009. |
| [takafumi-09:2007] |
Takafumi Hayashi, Toshiaki Miayzaki, and Senro Saito. Messaging Network for surviving info-plosion, 2007-2008. |
| [takafumi-10:2007] |
Takafumi Hayashi. Research on the method of working out Enterprise Security plan for local government, Fukushima Prefectural Foundation, 2007. |
Academic Activities
| [sding-06:2007] |
S. Ding, 2007. The Association for Computing Machinery (ACM), Membership |
| [sding-07:2007] |
S. Ding, 2007. Reviewer for Signal Processing, Elsevier |
| [sding-08:2007] |
S. Ding, 2007. Institute of Electrical and Electronics Engineers (IEEE), Membership. |
| [sding-09:2007] |
S. Ding, 2007. IEEE Signal Processing Society, Membership. Reviewers for the IEEE Transactions on Signal Processing and IEEE Signal Processing Letters |
| [sding-10:2007] |
S. Ding, 2007. Program committee member of The Second International Conference on Innovative Computing, Information and Control (ICICIC 2007) |
| [sding-11:2007] |
S. Ding, 2007. IEICE, Membership |
| [sding-12:2007] |
S. Ding, 2007. Review committee member candidate for Grants-In-Aid for Scienti c Research projects, JSPS |
| [sding-13:2007] |
S. Ding, 2007. Reviewer for IEEE Transactions on Signal Processing and IEEE Signal Processing Letters |
| [sding-14:2007] |
S. Ding, 2007. Program Committee Member of 2007 IEEE International Conference on Computer and Information Technology (CIT 2007) |
| [sding-15:2007] |
S. Ding, 2007. Program Committee Member of The Fourth International Symposium on Neural Networks (ISNN 2007) |
| [sding-16:2007] |
S. Ding, 2007. The Acoustical Society of America (ASA), Membership |
| [takafumi-11:2007] |
Takafumi Hayashi, 2007. Reviewer of IEEE Communication Letters |
| [takafumi-12:2007] |
Takafumi Hayashi, 2007. Reviewer of ICC |
| [takafumi-13:2007] |
Takafumi Hayashi, 2007. Reviewer of IEICE Transactions |
| [takafumi-14:2007] |
Takafumi Hayashi, 2007. Reviewer of OE Magazine |
| [takafumi-15:2007] |
Takafumi Hayashi, 2007. Reviewer of IEEE Signal Processing Letters |
Patents
| [takafumi-16:2007] |
Takafumi Hayashi, Ltd. Fukushima Information Processing Center Co., Ltd. Fukushimaken Chuo Keisan Center Co., and Ltd. FSK Co. Onetime-password authentication system, Patent Pending 2008-000351, Japan, 2008., March 2008. |
Ph.D. and Other Theses
| [sding-17:2007] |
Kazuki Ichihara. Graduation Thesis: On-line Independent Component
Analays, University of Aizu, 2007. Thesis Advisor: Ding, S. |
| [sding-18:2007] |
YudaiYamaguchi. Graduation Thesis: Computer Simulations for Time-
Reversal Acoustics, University of Aizu, 2007. Thesis Advisor: Ding, S. |
| [sding-19:2007] |
Keisuke Yokozawa. Graduation Thesis: Quantitative Determination of
Mutual Information and Applications in Blind Source Separation, University
of Aizu, 2007. Thesis Advisor: Ding, S. |
| [sding-20:2007] |
Masahiro Sekine. Master Thesis: An Online Algorithm for Blind Source
Separation Using Constrained Natural Power Iterations and Non-linear PCA,
University of Aizu, 2007. Thesis Advisor: Ding, S. |
| [sding-21:2007] |
Takahiro Haneda. Graduation Thesis: An On-line Algorithm for Independent
Component Analysis based on Negentropy Maximization, University
of Aizu, 2007. Thesis Advisor: Ding, S. |
| [sding-22:2007] |
Hironori Uchiyama. Graduation Thesis: Pseudo On-line Processing For
Independent Component Analysys, University of Aizu, 2007. Thesis Advisor: Ding, S. |
| [takafumi-17:2007] |
Yooin CHOI. Ecient Downsizing for e-Government in Japan, University
of Aizu, March 2008. Thesis Advisor: Takafumi Hayashi |
| [takafumi-18:2007] |
Yuuki Sato. The Message Flow of a Messaging Network Using
SOARS, University of Aizu, 3 2008. Thesis Advisor: Takafumi Hayashi |
| [takafumi-19:2007] |
Nobuyoshi TAKAHASHI. Resequencers for a Messaging Networ,
University of Aizu, 3 2008. Thesis Advisor: Takafumi Hayashi |
| [takafumi-20:2007] |
Kensuke Tomita. An extensible translation system using messaging
network, University of Aizu, 3 2008. Thesis Advisor: Takafumi Hayashi |
| [takafumi-21:2007] |
Syuji Henmi. Master thesis, University of Aizu, 2008. Thesis Advisor: Takafumi Hayashi |
| [takafumi-22:2007] |
Mayumi Miyajima. Information Shareing Using Zachman Framework,
University of Aizu, March 2008. Thesis Advisor: Takafumi Hayashi |
| [takafumi-23:2007] |
Kensaku Kawauchi. High Speed Processing Distributed Using a
Messaging Network, University of Aizu, March 2008. Thesis Advisor: Takafumi Hayashi |
