 |
 |
 |
Professor |
Associate Professor |
Visiting Researcher |
- 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;
- 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-01:2006] |
Z. He, S. Xie, S. Ding, and A Cichocki. Convolutive Blind Source
Separation in the Frequency Domain Based on Sparse Representation.
IEEE Transactions on Audio, Speech and Language Processing,
15(5):1551.1563, 2007. |
| Convolutive blind source separation (CBSS) that exploits the sparsity of
source signals in the frequency domain is addressed in this paper. We assume
the sources follow complex Laplacian-like distribution for complex random
variable, in which the real part and imaginary part of complex-valued
source signals are not necessarily independent. Based on the maximum a
posteriori (MAP) criterion, we propose a novel natural gradient method for
complex sparse representation. Moreover, a new CBSS method is further developed
based on complex sparse representation. The developed CBSS algorithm
works in the frequency domain. Here, we assume that the source signals
are sufficiently sparse in the frequency domain. If the sources are sufficiently
sparse in the frequency domain and the filter length of mixing channels is
relatively small and can be estimated, we can even achieve underdetermined
CBSS. We illustrate the validity and performance of the proposed learning
algorithm by several simulation examples. |
|
| [takafumi-01:2006] |
Takafumi Hayashi. Zachman Framework for Realizing Information
Security of Local Governments. Journal of Japan Association
for Social Informatics, 19(2):73.82, 2007. |
| In this paper, we present a scheme to esablish the Information Security of
Local Governments |
|
| [takafumi-02:2006] |
Takafumi Hayashi. Binary Zero-Correlation Zone Sequence Set
Construction Using a Cyclic Hadamard Sequence. IEICE Transaction
of Fundamentals, E89-A(2):633.638, 2006. |
| In this paper, we present a scheme to esablish the Information Security of
Local Governments |
|
| [takafumi-03:2006] |
Takafumi Hayashi and Shinya Matsufuji. n Optimal Construction
of Two Classes of ZCZ Codes. IEICE Transaction of Fundamentals,
E89-A(9):2345.2350, 2006. |
| In this letter, we present a new approach to the construction of a new binary ZCZ sequence set. |
|
| [takafumi-04:2006] |
Takafumi Hayashi. Ternary Sequence Set having Periodic and
Aperiodic Zero-Correlation Zone. IEICE Transaction of Fundamentals,
E89-A(6):1825.1831, 2006. |
| In this letter, we present a new approach to the construction of a novel ternary
ZCZ sequence set. |
Referred Proceeding Papers
| [sding-02:2006] |
S. Ding. A Power Iteration Algorithm for ICA Based on Diagonalizations
of Non-Linearized Covariance Matrix. In Proc. International
Conference on Innovative Computing, Information and Control 2007
(ICICIC-06), pages 730.733. IEEE, International Conference on Innovative
Computing, Information and Control 2007 (ICICIC-06), IEEE,
2006. |
| In this paper, we propose a novel algorithm for independent component analysis
(ICA) that is analog of the power iteration for solving the eigenvalue problem
of a matrix. In each iteration the updating of ICA matrix is fully-multiplicative,
rather than the partly multiplicative and partly additive in the conventional
learning algorithms. Therefore, this algorithm presents a new class of algorithm
to the ICA algorithms. The cost function for algorithm is based on a diagonality
of a non-linearized covariance matrix. One of desired features is that the
algorithm does not include any pre-designated parameter such as the learning
step size, which is promising for applications to ICA with unknown types of
sources. We also give conditions for choices of the non-linear functions. |
|
| [sding-03:2006] |
S. Ding. Independent Component Analysis Based on Learning Updating
with Forms of Matrix Transformations and the Diagonalization
Principle. In Proc. Japan-China Joint Workshop on Frontier of Computer
Science & Technology (FCSTf06), pages 203.209. IEEE, Japan-
China Joint Workshop on Frontier of Computer Science & Technology
(FCSTf06), IEEE, 2006. |
| Power iteration (PI) is a new algorithm for independent component analysis
(ICA), which has some desired features. One of features is that the algorithm
does not include any predetermined parameter such as the learning step size as
in the gradient-based algorithm, which is especially expected for ICA applications
with unknown types of sources. Another feature is that, in each iteration,
the updating of ICA matrix is fully-multiplicative, rather than the additive updating in the conventional gradient learning algorithms. The criterion for the independence between outputs is based on diagonality of a non-linearized
covariance matrix that is defined by ICA outputs and non-linear mapped ICA
outputs. In this paper, we study the algorithm mathematically to analyze why
and how the algorithm works. We show that in the algorithm the learning updating
is in the form of matrix transformation acting on the ICA matrix. Such
a updating allows a finite scale learning, which is essentially different from that
only the small enough scale learning controlled by the learning step size is allowed,
in a gradient-based algorithm.We also analyze the relation with the well
known algorithms, such as, the Bussgang algorithm and the non-linear PCA. |
|
| [sding-04:2006] |
S. Ding. Independent Component Analysis without Predetermined
Learning Parameter. In Proc. 2006 IEEE International Conference on
Computer and Information Technology (CIT 2006), pages 135.139. 2006
IEEE International Conference on Computer and Information Technology
(CIT 2006), IEEE, 2006. |
| This paper presents a power iteration (PI) algorithm for independent component
analysis (ICA), such that it is termed as fPowerICAf. In each iteration the
updating of ICA matrix is fully-multiplicative, rather than the partly multiplicative
and partly additive as in the conventional learning algorithms. Therefore,
this algorithm presents a new algorithm class to ICA. The criterion for
the independence between outputs is based on diagonality of a nonlinearized
covariance matrix that is define both by ICA outputs and non-linear mapped
ICA outputs. The activation function, which features the probability distribution
of sources, is chosen as such a non-linear map. One of desired features
is that the algorithm does not include any predetermined parameter such as
the learning step size as in the gradient-based algorithm, which is especially
promising for ICA applications to such cases with unknown types of sources.
Numerical results show the effectiveness of PowerICA. |
|
| [takafumi-05:2006] |
Takafumi Hayashi. A Novel Class of Zero-Correlation zone
Sequence Sets using A Perfect Sequence. In Proc. of IASTED Signal
and Image Processing 2006, pages 459.464. IASTED, 2006. |
| We prposed a new class of ZCZ sequence set |
|
| [takafumi-06:2006] |
Takafumi Hayashi. Schemes for Realizing Total Security in
Information Systems. In Proc. of e-Governance2006, 5th International
Conference on ICT and Higher Education. International Academy of
CIO, 2006. |
| We prposed a new schme to realize total security in Infotmation Systems |
Grants
| [sding-05:2006] |
S. Ding. Researches of real-time signal processing for blind source separationin convolutive mixing environment and real-time signal processing forindependent component analysis, 2004-2006. |
| This is supported as the project No.16500134, 2004 Grants-In-Aid forScientific
Research, Ministry of Education, Culture, Sports, Science andTechnology,
Japan. We research on blind source separation (BSS) of audiosignals in the
convolutive mixing environment and real-time signalprocessing for independent
component analysis (ICA) |
|
| [sding-06:2006] |
S. Ding. Research on the Warning Noise Cancellation from Audio Recording in BWR Operator Training, 2006-2006. |
| Supported by Boiling Water Reactor (BWR) Operator Training Center Corporation,
651 Chuodai Ottozawa, Ohkuma-Machi Futaba-Gun, Fukushima-Ken,
979-1301. |
|
| [takafumi-07:2006] |
Takafumi Hayashi. Research on the method of working out Enterprise Security plan for local government, Fukushima Prefectural Foundation, 2006. |
Academic Activities
| [sding-07:2006] |
S. Ding, 2006. Institute of Electrical and Electronics Engineers (IEEE), Membership. |
| [sding-08:2006] |
S. Ding, 2006. IEEE Signal Processing Society, Membership.Reviewers for the IEEE Transactions on Signal Processing and IEEE Signal Processing Letters |
| [sding-09:2006] |
S. Ding, 2006. Program Committee Member of 2006 IEEE International Conference on Computer and Information Technology (CIT 2006) |
| [sding-10:2006] |
S. Ding, 2006. Program Committee Member of Japan-China Joint Workshop on Frontier of Computer Science and Technology (FCST 2006) |
| [sding-11:2006] |
S. Ding, 2006. IEICE, Membership |
| [sding-12:2006] |
S. Ding, 2006. The Association for Computing Machinery (ACM), Membership |
| [sding-13:2006] |
S. Ding, 2006. The Acoustical Society of America (ASA), Membership |
| [sding-14:2006] |
S. Ding, 2006. Review committee member candidate for Grants-In-Aid forScientific Research projects, JSPS |
| [sding-15:2006] |
S. Ding, 2006. Reviewer for Signal Processing and Communications, Hindawi Publishing Corporation |
| [sding-16:2006] |
S. Ding, 2006. Reviewer for IEEE Transactions on Systems, Man, and Cybernetics |
| [sding-17:2006] |
S. Ding, 2006. Reviewer for Neurocomputing, Elsevier |
| [takafumi-08:2006] |
Takafumi Hayashi, 2006. Reviewer of IEEE Communication Letters |
| [takafumi-09:2006] |
Takafumi Hayashi, 2006. Reviewer of IEEE Signal Processing Letters |
| [takafumi-10:2006] |
Takafumi Hayashi, 2006. Reviewer of ICC |
| [takafumi-11:2006] |
Takafumi Hayashi, 2006. Reviewer of IEICE Transactions |
| [takafumi-12:2006] |
Takafumi Hayashi, 2006. Reviewer of OE Magazine |
Ph.D. and Other Theses
| [sding-18:2006] |
Satoshi Matsuoka. Graduation Thesis: Efficiencies of Acoustical
Convergence in Realistic Environments by Time Reversal Processing,
University of Aizu, 2006. Thesis Advisor: Ding, S. |
| [sding-19:2006] |
Naoto Sakurai. Graduation Thesis: Computer Simulation for
Time- and Space-Convergences in Time-Reversal Acoustics, University
of Aizu, 2006. Thesis Advisor: Ding, S. |
| [takafumi-13:2006] |
Tomoyasu Yoshida. Graduation Thesis: A scheme for overcoming
the digital divide, University of Aizu, 2007. Thesis Advisor: Takafumi Hayashi |
| [takafumi-14:2006] |
Hiroki Endou. Graduation Thesis: Exploiting Information
Technology for Japanese Sarbanes - Oxley Act, University of Aizu, 2007. Thesis Advisor: Takafumi Hayashi |
| [takafumi-15:2006] |
Yuuki Taguchi. Graduation Thesis: Evaluation of Image Watermarking
using mathematical morphology, University of Aizu, 2007. Thesis Advisor: Takafumi Hayashi |
| [takafumi-16:2006] |
Chiharu Igarashi. Graduation Thesis: Performance Evaluation
of Audio Digital Watermarking using Zero-correlation Zone Sequences,
University of Aizu, 2007. Thesis Advisor: Takafumi Hayashi |
| [takafumi-17:2006] |
Kaoru Kobayashi. Graduation Thesis: Information security
education for educational institution, University of Aizu, 2007. Thesis Advisor: Takafumi Hayashi |
| [takafumi-18:2006] |
Motonari Yamazaki. Graduation Thesis: An Information Management
Scheme for surviving the i-explosion, University of Aizu, 2007. Thesis Advisor: Takafumi Hayashi |
