[Japanese version]
Hiroshi Sekigawa
Senior Research Scientist
Computing Theory Research Group
Innovative Communication Laboratory
NTT Communication Science Laboratories
3-1 Morinosato-Wakamiya, Atsugi, Kanagawa
243-0198 Japan
E-Mail: sekigawaXtheory.brl.ntt.co.jp (X = @)
Last modified: August 19, 2009
Research Interests
- Symbolic and Algebraic Computation
- Symbolic-Numeric Computation
Biography
| 1986.3: |
B.S. in mathematics from the University of Tokyo. |
| 1989.3: |
M.S. in mathematics from the University of Tokyo. |
| 2004.2: |
Ph.D. in mathematical sciences from the University of Tokyo. |
|
Ph.D. Thesis: |
|
Zero Determination of Algebraic Numbers
using Approximate Computation and
its Application to Algorithms in Computer Algebra
[Pdf (271KB)] |
- 1989.4: Joined Nippon Telegraph and Telephone Corporation (NTT)
-
- 1989.5 - 1994.6:
- Research on computer-aided design for LSIs
- 1994.6 - 2000.3:
- Research on symbolic and algebraic computation,
symbolic-numeric computation
- 2000.4 - 2002.3: Business Communications Headquarters,
Nippon Telegraph and Telephone West Corporation
-
- 2002.4 - : NTT
- Research on symbolic and algebraic computation,
symbolic-numeric computation
Society Membership
Selected Publications
2009
-
K. Shirayanagi and H. Sekigawa,
Reducing Exact Computations to Obtain Exact Results Based on
Stabilization Techniques,
Proc. International Workshop on Symbolic-Numeric Computation 2009
(SNC2009), pp. 191-197, 2009.
-
H. Sekigawa,
On Real Factors of Real Interval Polynomials,
Journal of Symbolic Computation, Vol. 44, No. 7, pp. 908-922, 2009.
-
Y. Nakajima, Y. Kawano, H. Sekigawa, M. Nakanishi, S. Yamashita,
and Y. Nakashima,
Synthesis of Quantum Circuits for d-level Systems by using
Cosine-Sine Decomposition,
Quantum Information and Computation,
Vol. 9, No. 5&6, pp. 423-443, 2009.
-
H. Sekigawa,
Combining Symbolic and Numeric Computation,
(in Japanese),
IPSJ Magazine,
Vol. 50, No. 4, pp. 342-348, 2009.
2008
-
K. Shirayanagi and H. Sekigawa,
A New Groebner Basis Conversion Method Based on the Stabilization
Techniques,
Theoretical Computer Science, Vol. 409, pp. 311-317, 2008.
-
H. Sekigawa,
The Nearest Polynomial with a Zero in a Given Domain,
Theoretical Computer Science, Vol. 409, pp. 282-291, 2008.
-
H. Sekigawa,
The Nearest Real Polynomial with a Real Multiple Zero in a Given
Real Interval,
Proc. Asian Symposium on Computer Mathematics 2007 (ASCM2007),
Lecture Notes in Computer Science 5081, pp. 32-41, 2008.
-
H. Sekigawa,
The Nearest Polynomial with a Zero in a Given Domain from a
Geometrical Viewpoint,
Proc. International Symposium on Symbolic and Algebraic Computation
(ISSAC2008), pp. 287-294, 2008.
-
Y. Nakajima, Y. Kawano, and H. Sekigawa,
Efficient Quantum Circuits for Approximating the Jones Polynomial,
Quantum Information and Computation,
Vol. 8, No. 5, pp. 489-500, 2008.
2007
-
H. Sekigawa and K. Shirayanagi,
On the Location of Pseudozeros of a Complex Interval Polynomial,
Mathematics in Computer Science,
Vol. 1, No. 2, pp. 321-335, 2007.
-
Y. Nakajima, Y. Kawano, and H. Sekigawa,
Synthesis of Quantum Circuits for d-level Systems,
Proc. Asian Conference on Quantum Information Science (AQIS2007),
pp. 135-136, 2007.
-
H. Sekigawa,
On Real Factors of Real Interval Polynomials,
Proc. International Symposium on Symbolic and Algebraic Computation
(ISSAC2007), pp. 331-338, 2007.
-
P. Khungurn, H. Sekigawa, and K. Shirayanagi,
Minimum Converging Precision of the QR-Factorization Algorithm for
Real Polynomial GCD,
Proc. International Symposium on Symbolic and Algebraic Computation
(ISSAC2007), pp. 227-234, 2007.
-
H. Sekigawa,
The Nearest Polynomial with a Zero in a Given Domain,
Proc. International Workshop on Symbolic-Numeric Computation 2007
(SNC2007), pp. 190-196, 2007.
-
H. Sekigawa and K. Shirayanagi,
On the Location of Zeros of an Interval Polynomial,
Symbolic-Numeric Computation,
D. Wang and L. Zhi (eds.), Birkhaeuser, pp. 167-184, 2007.
2006
-
H. Sekigawa and K. Shirayanagi,
Locating Real Multiple Zeros of a Real Interval Polynomial
(in Japanese),
Journal of Japan Society for Symbolic and Algebraic Computation,
Vol. 13, No. 1, pp. 68-71, 2006.
-
Y. Nakajima, Y. Kawano, and H. Sekigawa,
Quantum Circuit Design
(in Japanese),
IPSJ Magazine,
Vol. 47, No. 12, pp. 1335-1340, 2006.
-
T. Moriya, N. Harada, Y. Kamamoto, and H. Sekigawa,
MPEG-4 ALS--International Standard for Lossless Audio Coding,
NTT Technical Review, Vol. 4, No. 8, pp. 40-45, 2006.
-
H. Sekigawa and K. Shirayanagi,
Locating Real Multiple Zeros of a Real Interval Polynomial,
Proc. International Symposium on Symbolic and Algebraic Computation
(ISSAC2006), pp. 310-317, 2006.
-
K. Miyamoto, W. Yamamoto, H. Sekigawa, and K. Shirayanagi,
Deductive System for Human-like Proofs in Geometry,
Proc. 13th Symposium on the Integration of Symbolic Computation and
Mechanized Reasoning 2006 (Calculemus'06),
pp. 5-20, 2006.
- H. Sekigawa and K. Shirayanagi,
On the Location of Zeros of an Interval Polynomial (in Japanese),
IEICE Trans. A,
Vol. J89-A, No. 3, pp. 199-216, 2006.
-
N. Harada, T. Moriya, H. Sekigawa, K. Shiaryanagi, and Y. Kamamoto,
Lossless Compression of IEEE754 Floating-Point Signal in ISO/IEC
MPEG-4 Audio Lossless Coding (ALS) (in Japanese),
IEICE Trans. B,
Vol. J89-B, No. 2, pp. 204-213, 2006.
-
Y. Nakajima, Y. Kawano, and H. Sekigawa,
A New Algorithm for Producing Quantum Circuits using KAK
Decompositions,
Quantum Information & Computation,
Vol. 6, No. 1, pp. 67-80, 2006.
2005
-
H. Sekigawa and K. Shirayanagi,
On the Location of Zeros of a Real Interval Polynomial
(in Japanese),
Journal of Japan Society for Symbolic and Algebraic Computation,
Vol. 12. No. 2, pp. 35-38, 2005.
-
H. Sekigawa and K. Shirayanagi,
On the Location of Pseudozeros of a Complex Interval Polynomial,
Proc. Asian Symposium on Computer Mathematics (ASCM2005),
pp. 231-234, 2005.
-
H. Nakajima, Y. Kawano, and H. Sekigawa,
An Algorithm for Decomposing Unitary Matrices using Cartan
Decomposition,
Abstracts of 11th International Conference on Applications of
Computer Algebra (ACA'2005), p. 24, 2005.
-
H. Sekigawa and K. Shirayanagi,
On the Location of Zeros of a Complex Interval Polynomial,
Abstracts of 11th International Conference on Applications of
Computer Algebra (ACA'2005), p. 15, 2005.
-
H. Sekigawa and K. Shirayanagi,
On the Location of Zeros of an Interval Polynomial,
Proc. International Workshop on Symbolic-Numeric Computation 2005
(SNC2005), pp. 144-165, 2005.
-
Y. Kawano, K. Kimura, H. Sekigawa, M. Noro, and K. Shirayanagi,
Exact CNOT on an Exchange-Only Quantum Computer (in Japanese),
Journal of Japan Society for Symbolic and Algebraic Computation,
Vol. 11. No. 2, pp. 55-58, 2005.
-
Y. Kawano, K. Kimura, H. Sekigawa, M. Noro, K. Shirayanagi,
M. Kitagawa, and M. Ozawa,
Existence of the Exact CNOT on a Quantum Computer with the
Exchange Interaction,
Quantum Information Processing, Vol. 4, No. 2, pp. 65-85,
2005.
-
N. Harada, T. Moriya, H. Sekigawa, and K. Shiaryanagi,
Lossless Compression of IEEE Floating-point Audio using Approximate
Common Factor Coding and Masked-LZ Compression,
Poster presentation at
AES 118th Convention, 2005.
2004
- H. Sekigawa,
Zero Determination of Algebraic Numbers using Approximate
Computation (in Japanese), Bulletin of the Japan Society for
Industrial and Applied Mathematics, Vol. 14, No. 4, pp. 75-78,
2004.
- K. Miyamoto, K. Ohya, H. Sekigawa, and K. Shirayanagi,
An Efficient Method of Finding Auxiliary Lines in Automated Geometry
Theorem Proving
(in Japanese), Proc. of the RIMS Workshop "Computer
Algebra--Design of Algorithms, Implementations and Applications,"
Kokyuroku 1395, pp. 157-163, Research Institute for Mathematical
Sciences, Kyoto Univ., 2004.
- Y. Kawano, K. Kimura, and H. Sekigawa,
On Quantum Gates in Decoherence-Free Subspaces
(in Japanese), Technical Report of IEICE,
COMP2004-23, pp. 33-39, 2004.
2003
- K. Miyamoto, H. Sekigawa, K. Shirayanagi, and F. Machida,
On a Method for Automated Generation of Readable Proofs in
Euclidean Geometry
(in Japanese), Proc. of the RIMS Workshop "Computer
Algebra--Algorithms, Implementations and Applications,"
Kokyuroku 1335, pp. 20-27, Research Institute for Mathematical
Sciences, Kyoto Univ., 2003.
2002
- K. Shirayanagi and H. Sekigawa,
New Scientific Computing--Symbolic-Numeric Algebra
(in Japanese),
NTT R&D, Vol. 51, No. 10, pp. 778-783, 2002.
2000
- H. Sekigawa,
A Remark on the Polynomial Determining Superstable Points in the
Mandelbrot Set,
Josai Mathematical Monographs 2, NLA99 Computer Algebra,
pp. 11-13, 2000.
- H. Sekigawa and K. Shirayanagi,
Automatic Algorithm Stabilization System,
Josai Mathematical Monographs 2, NLA99 Computer Algebra,
pp. 159-168, 2000.
1999
- H. Sekigawa and K. Koyama,
Nonexistence Conditions of a Solution for the Congruence
x1k+...+xsk=N
(mod pn),
Mathematics of Computation, Vol. 68, No. 227, pp. 1283-1297, 1999.
1998
- H. Sekigawa,
Using Interval Computation with the Mahler Measure for Zero
Determination of Algebraic Numbers,
Josai Information Sciences Researches,
Vol. 9, No. 1, pp. 83-99, 1998.
1997
- K. Shirayanagi and H. Sekigawa,
An Interval Method Based on Zero Rewriting and its Application to
Sturm's Algorithm (in Japanese),
IEICE Trans. A,
Vol. J80-A, No. 5, pp. 791-802, 1997.
- K. Koyama, Y. Tsuruoka, and H. Sekigawa,
On Searching for Solutions of the Diophantine Equation
x3+y3+z3=n,
Mathematics of Computation, Vol. 66, No. 218, pp. 841-851, 1997.
1996
- H. Sekigawa,
Using Interval Arithmetic and Polynomial Norms to Determine Signs of
Algebraic Numbers,
Proc. 2nd Asian Symposium on Computer Mathematics (ASCM'96),
pp. 43-53, 1996.
- H. Sekigawa,
An Interval Arithmetic with Algebraic Complexity to Determine the
Signs of Algebraic Expressions,
Abstracts of 4th International Symposium on Effective Methods in
Algebraic Geometry (MEGA'96),
p. 43, 1996.
1995
- H. Sekigawa and K. Shirayanagi,
Computing Diophantine Approximate Groebner Bases,
Proc. 1st Asian Technology Conference in Mathematics (ATCM'95),
pp. 717-726, 1995.
-
H. Sekigawa and K. Shirayanagi,
Zero Rewriting in Interval Computation and Its Application to
Sturm's Algorithm,
Poster presentation at
International Symposium on Symbolic and Algebraic Computation
(ISSAC'95).
|
NTT Communication Science Laboratories
|
Innovative Communication Laboratory
|
Computing Theory Research Group |