Professor 
Associate Professor 
Assistant Professor 
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, statistical signal processing, neurocomputing, optimization, simulated
acoustics and related topics. 
Areas of our research interest include

The following combined research is running:

Faculty of the FCS laboratory teach Computer Literacy, Programming I, Algorithms
and Data Structures, Advanced Algorithms, Digital Signal Processing, Linear Systems,
Information Security, 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. 
[sding01:2009] 
W. Liu and S. Ding. Performance Analysis of the Iterative Decision
Method for Optimal Multiuser Detection. ICIC Express Letters, 3(3 (B)):615–
619, September 2009. 
The iterative decision method has been proposed to solve the optimal multiuser detection
(OMD) problem efficiently [6][9]. In contrast to conventional detection methods,
this method can determine most binary variables of OMD optimally, rather than approximately,
with a low computational complexity. However, the reason that the iterative
decision method works so efficiently for OMD has not yet been well established. In
this paper, we present a systematic answer to this question. Invoking the properties of
OMD, we prove that the iterative decision method can optimally determine the binary
variables of OMD with a high predictable probability and furthermore, we determine
the probability explicitly in terms of system configurations. These provide solid theoretical
foundations for the justification and efficiency of the iterative decision method
for solving the OMD problem. Since the probability depends on the configuration parameters
in a complex fashion, we also present an approximation for the probability
dependence that can be calculated more easily. 

[sding02:2009] 
W. Liu and S. Ding. The Diagonal Loading Beamformers for the PAM
Communication Systems. International Journal of Innovative Computing, Information
and Control, 5(9):2907–2916, September 2009. 
The diagonal loading method is a simple and efficient method that can improve the robustness
of beamformers. However, determining an ideal diagonal loading factor (DLF)
is not a trivial problem. Maximizing the signal to interferenceplusnoise ratio (SINR)
can be one criterion for determining an ideal DLF. Unfortunately, the maximizing
SINR is not realistic for practical applications. Although beamformers are widely used
in radar, sonar and many other applications, in this paper, we consider a beamformer
for PAM communication systems. In PAM communications, user information is coded
into a sequence with the constant modulus (CM) in the baseband. Obviously, if the
beamformer can cancel interference and noise sufficiently, the outputs of the beamformer
should satisfy the CM condition more precisely. Therefore, minimizing the CM
error (MCME) criterion can act as a reasonable substitution for maximizing the SINR
criterion. In this paper, we present a cost function for the MCME criterion. We also
propose a search algorithm for DLF determination by minimizing the cost function.
Numerical experiments show the effectiveness of the proposed method. 

[takafumi01:2009] 
T. Hayashi. A Class of ZeroCorrelation Zone Sequence Set Using a
Perfect Sequence. Signal Processing Letters, IEEE, 16(4):331–334, April 2009. 
This letter introduces a novel method of sequence construction having a zerocorrelation
zone. The crosscorrelation function and the sidelobe of the autocorrelation function
of the proposed sequence set is zero for the phase shifts within the zerocorrelation zone.
The proposed zerocorrelation zone sequence set can be generated from an arbitrary
perfect ternary sequence, the length of which is the product of a pair of odd integers (
(2k+1)(2n+1) for k ges 1 and n ges 0). The width of the zerocorrelation zone of the
proposed sequence set can be longer than the length of the perfect sequence that is used
for constructing the proposed sequence set. The proposed sequence construction can
generate an optimal zerocorrelation zone sequence set that satisfies the theoretical
bound of the sequence member size for the zerocorrelation zone and the sequence
period. 
[sding03:2009] 
W. Liu, Q. Liu, J. Li, M. Jin, and S. Ding. An Iterative Algorithm for
Joint Beamforming and DoA Estimation. In Proc. The 19th Intelligent System
Symposium (Fan 2009) and The 1st International Workshop on Aware
Computing (IWAC09), pages 674–678. Japan Society for Fuzzy Theory and
Intelligent Informatics, International Workshop on Aware Computing Organizing
Committee and The University of Aizu, Japan Society for Fuzzy
Theory and Intelligent Informatics, 2009. 
The MUSIC direction of arrival (DoA) estimation algorithm is known to degrade
due to effects of imprecise knowledge about the array manifold. We have made some
numerical experiments for the fact revisited. The simulation results showed an interesting
phenomenon that has not been reported yet in literature. That is, if there
are more than one signal sources impinging to the array, the performance of MUSIC
algorithm really degraded dramatically due to the effects of imprecise array manifold;
however, if there is only one signal source impinging to the array, the DoA estimation
for the single source is robust. Invoking this phenomenon, we propose an iterative
algorithm for joint beamforming and DoA estimation. In the viewpoint of DoA, an
essential difference between the proposed algorithm and conventional DoA estimation
algorithms is that the proposed algorithm includes a processing of beamforming
but the conventional DoA algorithms do not include it. Numerical experiments have
shown the robustness of the proposed algorithm against imprecise knowledge on the
array manifold. 

[takafumi02:2009] 
Yooin Choi, J. Terazono, K. Kawauchi, K. Itabashi, H. Fukuhara,
I. Koseda, R. Fujita, T. Miyazaki, S. Saito, J. Iwase, and T. Hayashi. Networkcentric
mashup for a sensor network that uses a messaging network. In
ICCASSICE, 2009, pages 1980–1983, Aug. 2009. 
The present paper describes a mashup and an approach by which to integrate a sensor
network using a messaging network. A messaging network is an overlay network that
has a rich set of message handling capabilities. The use of a messaging network
enables the complexity and maintenance burden of the integrated sensor information
systems to be reduced. Mashup refers to the use of different data or services for the
purpose of providing valueadded information or efficient use of information. The
proposed approach generates an SOAbased sensor network design and mashup. 

[takafumi03:2009] 
J. Terazono, H. Fukuhara, T. Yamada, T. Nihei, K. Suzuki,
I. Koseda, R. Fujita, T. Miyazaki, S. Saito, A. Kara, and T. Hayashi. A sensor
network using contentaware messaging network architecture. In ICCASSICE,
2009, pages 5055–5058, Aug. 2009. 
The present paper describes an approach to the construction of a sensor network
using a messaging network. A messaging network is an overlay network with a set of
contentaware message handling capabilities. The use of a messaging network can
reduce the complexity and maintenance burden of integrated sensor information
systems. Message mediation (a function of the messaging network) enables interoperation
of various applications and integration of diverse sensor data. Subscription
(another concept in the messaging network) enables proper information delivery of
the sensor data to each user. The proposed approach is helpful in implementing an
SOAbased sensor network and enables flexible sensor network configuration and
utilization. 

[takafumi04:2009] 
Junya Terazono (The University of Aizu), Ryosuke Nakamura, Shinsuke
Kodama, Naotaka Yamamoto (AIST), Hirohide Demura, Naru Hirata,
Yoshiko Ogawa (The University of Aizu), Jun’ichi Haruyama, Makiko Ohtake
(JAXA), Tsuneo Matsunaga (NIES), Taro Suzuki, and Takafumi Hayashi
(The University of Aizu). WISECAPS: An Integrated and Secure Webbased
Environment for Analysis and browsing of Lunar and Planetary Data.
In Proc. The 41st Lunar and Planetary Science Conference, 2010. 
We are now constructing aWebGIS based framework called ‘WISECAPS,’ a virtual
research environment to share and browse the data under secured data access. This
presentation will address on current implementation status and future prospective. 

[takafumi05:2009] 
T. Hayashi and S. Matsufuji. A generalized construction of optimal
zerocorrelation zone sequence set from a perfect sequence. In Signal Design
and its Applications in Communications, 2009. IWSDA ’09. Fourth International
Workshop on, pages 24–27, Oct. 2009. 
The present paper introduces a new approach to the construction of a sequence
set with a zerocorrelation zone (ZCZ). This sequence set is referred to as a zerocorrelation
zone sequence set. The proposed sequence construction can generate an
optimal ZCZ sequence set, the member size of which reaches the theoretical bound.
The proposed sequence construction generates a ZCZ sequence set from a perfect
sequence and a Hadamard matrix. 

[takafumi06:2009] 
S. Matsufuji, T. Matsumoto, T. Hayashida, T. Hayshi, N. Kuroyanagi,
and P. Fan. On a ZCZ code including a sequence useful for synchronization.
In Signal Design and its Applications in Communications, 2009.
IWSDA ’09. Fourth International Workshop on, pages 28–31, Oct. 2009. 
This paper presents a ZCZ code which are combinedly used to spread data and
synchronization symbol in quasisynchronous CDMA systems using PSK, ASK or
BFSK. Furthermore a simple matched filter is presented, which calculates simultaneously
correlations with arbitrary sequences in the ZCZ code. 

[takafumi07:2009] 
Junya Terazono, Noriaki Asada, Hirohide Demura, Naru Hirata
(The University of Aizu), Kazuto Saiki (Osaka University), Akira Iwasaki
(The University of Tokyo) Ryuichi Oka, Takafumi Hayashi, Taro Suzuki
(The University of Aizu), Hideaki Miyamoto (The University of Tokyo),
Junichi Haruyama, Makiko Ohtake (JAXA), Tsuneo Matsunaga (NIES),
Shinichi Sobue, Hayato Okumura (JAXA), Taketo Fujita, and Aya Yamamoto
(RESTEC). Integrated Lunar WebGIS Environment Using Data
Obtained by Lunar Exploration. In Proc. The 40th Lunar and Plaentary
Science Conference, 2009. 
The dissemination of WebGIS (Geographical Information System) in the research
field demonstrates that the map, shown in the web pages, are the most basic data for
the scientific activity. This fact also have an effect on lunar exploration. In Kaguya
project, the handling of huge quantities of data will be the key to promote research.
Most of the data are obtaind by LISM, Lunar Imager and Spectrometer, consists of
Multiband Imager (MI), Spectral Profiler (SP) and Terrain Camera (TC). The image
data will form the base of the Kaguya data for global mapping and topographical
understanding of the moon. The networkbased collaboration environment enables
them to utilize those image data without carrying them on in the meeting and share
their result on the net. It will contribute in the increasing of scientific productivity
and indurate future style of research in lunar exploration. In this presentation,
we will show current implementation status of the WebGIS based collaboration
environment using lunar exploration data. 
[takafumi08:2009] 
H. Fukuhara, I. Koseda, R. Fujita, T. Miyazaki, S. Saito, J. Iwase, and T. Hayashi. A Rapid Construction of a Versatile Cloud Computing System Infrastructure. In Proc. of 2009 Autumn Conf. of International C I O Forum, 2009. 
A novel elastic Cloud Computing Architecture using a virtual structured overlay
network, which gives contentaware networking, is proposed. Several application are
presented.(in Japanese) 

[takafumi09:2009] 
T. Hayashi, H. Fukuhara, I. Koseda, R. Fujita, J. Terazono, T. Miyazaki, J. Iwase, and A. Kara. セSecure Loosely Coupled Integration Infrastructure for Cloud Computing. In Proc. of 2009 Joint Conf. of JSIS and JASI, 2009. 
A novel intelligent infrastructure using networkcentric approach and structured
overlay network. Application of the proposed scheme to local information infrastructure
was presented.(in Japanese) 

[takafumi10:2009] 
J. Terazono, H. Fukuhara, M.S aito, T. Miyazaki, S. Saito, J. Iwase, and T. Hayashi. NetworkCentric Architecture Intelligent Infrastructure. In Proc. of the 50th IPSJ Annual Conf., 2010. 
A novel networkcentric approach for the construction and the maintenance intelligent
infrastructure was proposed.(in Japanese) 

[takafumi11:2009] 
T. Yamada, K. Suzuki, T. Nihei, J. Terazono, K. Itabashi, H. Hashima, Y. Yabuki, Y. Tannno, H. Fukuhara, K. Shiono, and T. Hayashi. A robust elearning system using contentaware network. In Proc. of the 50th IPSJ Annual Conf., 2010. 
A novel robust elearning system using contentaware network is proposed. (in
Japanese) 
[sding04:2009] 
S. Ding. Blind source separation using sparse frame representation for multi source signals and its applications, 20082010. 
Scientific Research C, No. 20500209, 2008 GrantsInAid for Scientific Research, Japan
Society for the Plomotion of Science (JSPS) 

[takafumi12:2009] 
Takafumi Hayashi. Study of of ternary sequence set having zerocorrelation
zone for periodicand Aperiodic correlation functions, 20072009. 
GrantsInAid for Scientific Research, Japan Society for the Plomotion of Science
(JSPS) 

[yodai01:2009] 
Yodai Watanabe. GrantinAid for Encouragement of Young Scientists (B) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, 20092011. 
[sding05:2008] 
S. Ding, 2009. Review committee member candidate for GrantsInAid for Scientific Research projects, JSPS 
[sding06:2009] 
S. Ding, 2009. Served as the Program Committee Chair for The 19th Intelligent System Symposium (FAN 2009) and The 1st International Workshop on Aware Computing (IWAC2009) 
[sding07:2009] 
S. Ding, 2009. TProgram Committee member of The Fourth International Conference on Innovative Computing, Information and Control (ICICIC 2009) 
[sding08:2009] 
S. Ding, 2008. Organizing Committee member of Second International Symposium on Intelligent Informatics (ISII2009) 
[sding09:2009] 
S. Ding, 2009. Institute of Electrical and Electronics Engineers (IEEE), Membership. 
[sding10:2009] 
S. Ding, 2009. IEEE Signal Processing Society, Membership. Reviewers for the IEEE Transactions on Signal Processing and IEEE Signal Processing Letters 
[sding11:2009] 
S. Ding, 2009. IEICE, Membership 
[sding12:2009] 
S. Ding, 2009. The Association for Computing Machinery (ACM), Membership 
[sding13:2009] 
S. Ding, 2009. The Acoustical Society of America (ASA), Membership 
[takafumi14:2009] 
Takafumi Hayashi, 2009. Reviewer of Eletctronics Letters 
[takafumi15:2009] 
Takafumi Hayashi, 2009. Program Chair of CIT2009 
[takafumi16:2009] 
Takafumi Hayashi, 2009. Reviewer of IEEE Signal Processing Letters 
[takafumi17:2009] 
Takafumi Hayashi, 2009. Reviewer of IEEE Communication Letters 
[takafumi18:2009] 
Takafumi Hayashi, 2009. Reviewer of ICC 
[takafumi19:2009] 
Takafumi Hayashi, 2009. Reviewer of IEICE Transactions 
[takafumi20:2009] 
Takafumi Hayashi, 2009. Reviewer of OE Magazine 
[yodai02:2009] 
Wataru Matsumoto and Yodai Watanabe. Quantum key distribution method and communication device Registered United States Patent 7,609,839, October 2009. 
[yodai03:2009] 
Wataru Matsumoto and YodaiWatanabe. Quantum key delivery method and communication device Registered Japanese Patent 4290401, April 2009. 
[yodai04:2009] 
Wataru Matsumoto and Yodai Watanabe. Quantum key distribution method and communication device Registered Japanese Patent 4346929, July 2009. 
[sding14:2009] 
Hironori Uchiyama. Master Thesis: Solving the shortest route problem
by computer simulation for selforganizing of amoeba, University of Aizu, 2009.
Thesis Advisor: Ding, S. 
[sding15:2009] 
Hiroyuki Abe. Graduation Thesis: Improving the Wave Convergence
in Computer Simulations of the Time Reversal Acoustics, University of Aizu,
2009. Thesis Advisor: Ding, S. 
[sding16:2009] 
Takahiro Haneda. Master Thesis: Pseudo Online Independent Component
Analysis for Dynamical Mixtures of NonStationary Sources, University
of Aizu, 2009. Thesis Advisor: Ding, S. 
[sding17:2009] 
Keiji Muto. Graduation Thesis: Sparse Representation and Recovery of
NonSparse Signal, University of Aizu, 2009. Thesis Advisor: Ding, S. 
[sding18:2009] 
Noriyuki Takahashi. Graduation Thesis: Online Independent Component
Analysis by Maximizing Negentropy Approximated with Two NonLinear
Functions, University of Aizu, 2009. Thesis Advisor: Ding, S. 
[sding19:2009] 
Hironori Nihei. Graduation Thesis: Solving Permutation Switching
Problem in Online Fast FixedPoint Independent Component Analysis Algorithm,
University of Aizu, 2009. Thesis Advisor: Ding, S. 
[takafumi21:2009] 
Yoshinobu Tanno. Graduation Thesis: Efficient Information Management
for Information Explosion, University of Aizu, 2009. Thesis Advisor: Takafumi Hayashi 
[takafumi22:2008] 
Kana Itabashi. Graduation Thesis: NetworkCentric Web Filtering
Using a Messaging Network, University of Aizu, 2009. Thesis Advisor: Takafumi Hayashi 
[takafumi23:2009] 
Hidemi Takahashi. Graduation Thesis: An ELocal government
based on Enterprise Architecture, University of Aizu, 2009. Thesis Advisor: Takafumi Hayashi 
[takafumi24:2009] 
Yusei Yabuki. Graduation Thesis: Service Recovery for a Local
egovernment based on an Intelligent Infrastructure, University of Aizu, 2009. Thesis Advisor: Takafumi Hayashi 
[takafumi25:2009] 
Kensuke Tomita. Master Thesis: ContentAware Networking with
Protocol Buffers using Message Mediation, University of Aizu, 2009. Thesis Advisor: Takafumi Hayashi 
[takafumi26:2009] 
Yooin Choi. Master Thesis: Social Networking Service for Local
eGovernments using Cloud Computing and Contentaware Networking, University
of Aizu, 2009. Thesis Advisor: Takafumi Hayashi 
[sding20:2009] 
S. Ding. Blind source separation (BSS) and Independent component
analysis (ICA)Prince Shotoku would also be surprised. Japanese Magazine:
Fukushima no Shinro, No. 329, pp. 5457, January 2010. A general introduction for one of my research areas, Blind source separation (BSS) and Independent component analysis (ICA). 