317 research outputs found
Node Query Preservation for Deterministic Linear Top-Down Tree Transducers
This paper discusses the decidability of node query preservation problems for
XML document transformations. We assume a transformation given by a
deterministic linear top-down data tree transducer (abbreviated as DLT^V) and
an n-ary query based on runs of a tree automaton. We say that a DLT^V Tr
strongly preserves a query Q if there is a query Q' such that for every
document t, the answer set of Q' for Tr(t) is equal to the answer set of Q for
t. Also we say that Tr weakly preserves Q if there is a query Q' such that for
every t_d in the range of Tr, the answer set of Q' for t_d is equal to the
union of the answer set of Q for t such that t_d = Tr(t). We show that the weak
preservation problem is coNP-complete and the strong preservation problem is in
2-EXPTIME.Comment: In Proceedings TTATT 2013, arXiv:1311.505
高周波電力変換回路のための内部磁束密度分布に基づく空芯トランスの解析と設計
京都大学新制・課程博士博士(工学)甲第23201号工博第4845号新制||工||1757(附属図書館)京都大学大学院工学研究科電気工学専攻(主査)教授 引原 隆士, 教授 松尾 哲司, 特定教授 中村 武恒学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDFA
Non-divergent representation of non-Hermitian operator near the exceptional point with application to a quantum Lorentz gas
We propose a non-singular representation for a non-Hermitian operator even if
the parameter space contains exceptional points (EPs), at which the operator
cannot be diagonalized and the usual spectral representation ceases to exist.
Our representation has a generalized Jordan block form and is written in terms
of extended pseudo-eigenstates. Our method is free from a divergence in the
spectral representation at EPs, at which multiple eigenvalues and eigenvectors
coalesce and the eigenvectors cannot be normalized. Our representation improves
the accuracy of numerical calculations of physical quantities near EPs. We also
find that our method is applicable to various problems related to EPs in the
parameter space of non-Hermitian operators. We demonstrate the usefulness of
our representation by investigating Boltzmann's collision operator in a
one-dimensional quantum Lorentz gas in the weak coupling approximation
Broadband coherent Raman scattering spectroscopy at 50,000,000 spectra/s
Raman scattering spectroscopy is widely used as an analytical technique in
various fields, but its measurement process tends to be slow due to the low
scattering cross-section. In the last decade, various broadband coherent Raman
scattering spectroscopy techniques have been developed to address this
limitation, achieving a measurement rate of about 100 kSpectra/s. Here, we
present a significantly increased measurement rate of 50 MSpectra/s, which is
500 times higher than the previous state-of-the-art, by developing time-stretch
coherent Raman scattering spectroscopy. Our newly-developed system, based on a
mode-locked Yb fiber laser, enables highly-efficient broadband excitation of
molecular vibrations via impulsive stimulated Raman scattering with an
ultrashort femtosecond pulse and sensitive time-stretch detection with a
picosecond probe pulse at a high repetition rate of the laser. As a
proof-of-concept demonstration, we measure broadband coherent Stokes Raman
scattering spectra of organic compounds covering the molecular fingerprint
region from 200 to 1,200 cm-1. This high-speed broadband vibrational
spectroscopy technique holds promise for unprecedented measurements of
sub-microsecond dynamics of irreversible phenomena and extremely
high-throughput measurements
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