Articles
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08/04/2017--
08/04/2017
Short-range test of the universality of gravitational constant $G$ at the millimeter scale using a digital image sensor
The composition dependence of gravitational constant $G$ is measured at the
millimeter scale to test the weak equivalence principle, which may be violated
at short range through new Yukawa interactions such as the dilaton exchange
force. A torsion balance on a turning table with two identical tungsten targets
surrounded by two different attractor materials (copper and aluminum) is used
to measure gravitational torque by means of digital measurements of a position
sensor. Values of the ratios $\tilde{G}_{Al-W}/\tilde{G}_{Cu-W} -1$ and
$\tilde{G}_{Cu-W}/G_{N} -1$ were $(0.9 \pm 1.1_{\mathrm{sta}} \pm
4.8_{\mathrm{sys}}) \times 10^{-2}$ and $ (0.2 \pm 0.9_{\mathrm{sta}} \pm
2.1_{\mathrm{sys}}) \times 10^{-2}$ , respectively; these were obtained at a
center to center separation of 1.7 cm and surface to surface separation of 4.5
mm between target and attractor, which is consistent with the universality of
$G$. A weak equivalence principle (WEP) violation parameter of
$\eta_{Al-Cu}(r\sim 1\: \mathrm{cm})=(0.9 \pm 1.1_{\mathrm{sta}} \pm
4.9_{\mathrm{sys}}) \times 10^{-2} $ at the shortest range of around 1 cm was
also obtained.
K. Ninomiya
T. Akiyama
M. Hata
M. Hatori
T. Iguri
Y. Ikeda
S. Inaba
H. Kawamura
R. Kishi
H. Murakami
Y. Nakaya
H. Nishio
N. Ogawa
J. Onishi
S. Saiba
T. Sakuta
S. Tanaka
R. Tanuma
Y. Totsuka
R. Tsutsui
K. Watanabe
J. Murata
06/01/2025--
06/01/2025
LEMONADE: A Large Multilingual Expert-Annotated Abstractive Event Dataset for the Real World
This paper presents LEMONADE, a large-scale conflict event dataset comprising
39,786 events across 20 languages and 171 countries, with extensive coverage of
region-specific entities. LEMONADE is based on a partially reannotated subset
of the Armed Conflict Location & Event Data (ACLED), which has documented
global conflict events for over a decade.
To address the challenge of aggregating multilingual sources for global event
analysis, we introduce abstractive event extraction (AEE) and its subtask,
abstractive entity linking (AEL). Unlike conventional span-based event
extraction, our approach detects event arguments and entities through holistic
document understanding and normalizes them across the multilingual dataset. We
evaluate various large language models (LLMs) on these tasks, adapt existing
zero-shot event extraction systems, and benchmark supervised models.
Additionally, we introduce ZEST, a novel zero-shot retrieval-based system for
AEL.
Our best zero-shot system achieves an end-to-end F1 score of 58.3%, with LLMs
outperforming specialized event extraction models such as GoLLIE. For entity
linking, ZEST achieves an F1 score of 45.7%, significantly surpassing OneNet, a
state-of-the-art zero-shot baseline that achieves only 23.7%. However, these
zero-shot results lag behind the best supervised systems by 20.1% and 37.0% in
the end-to-end and AEL tasks, respectively, highlighting the need for further
research.
Sina J. Semnani
Pingyue Zhang
Wanyue Zhai
Haozhuo Li
Ryan Beauchamp
Trey Billing
Katayoun Kishi
Manling Li
Monica S. Lam
12/20/2017--
12/20/2017
Divisibility of class numbers of certain families of quadratic fields
We construct some families of quadratic fields whose class numbers are
divisible by $3.$ The main tools used are a trinomial introduced by Kishi and a
parametrization of Kishi and Miyake of a family of quadratic fields whose class
numbers are divisible by $3.$ At the end we compute class number of these
fields for some small values and verify our results.
Azizul Hoque
Kalyan Chakraborty
06/24/2004--
06/24/2004
Isovector and isoscalar spin-flip M1 strengths in $^{11}$B
The $^{11}$B($^3$He$, t$), $^{11}$B($d, d'$), and $^{11}$B($p, p'$) reactions
were measured at forward scattering angles including $0^\circ$ to study the
isovector and isoscalar spin-flip M1 strengths in $^{11}$B. The measured
$^{11}$B($^3$He$, t$) cross sections were compared with the results of the
distorted-wave impulse-approximation (DWIA) calculation, and the Gamow-Teller
(GT) strengths for low-lying states in $^{11}$C were determined. The GT
strengths were converted to the isovector spin-flip M1 strengths using the
isobaric analog relations under the assumption of the isospin symmetry. The
isoscalar spin-flip M1 strengths were obtained from the ($d, d'$) analysis by
assuming that the shape of the collective transition form factor with the same
${\Delta}J^\pi$ is similar in the $^{11}$B($d, d'$) and $^{12}$C($d, d'$)
reactions. The obtained isovector and isoscalar strengths were used in the DWIA
calculations for the $^{11}$B($p, p'$) reaction. The DWIA calculation
reasonably well explains the present $^{11}$B($p, p'$) result. However, the
calculated cross section for the 8.92-MeV 3/2$^-_2$ state was significantly
smaller than the experimental values. The transition strengths obtained in the
shell-model calculations were found to be 20-50% larger than the experimental
strengths. The transition strengths for the neutrino induced reactions were
estimated by using the isovector and isoscalar spin-flip M1 strengths. The
present results are quantitatively in agreement with the theoretical estimation
discussing the axial isoscalar coupling in the neutrino scattering process, and
are useful in the measurement of the stellar neutrinos using the neutral- and
charged-current reactions on $^{11}$B.
T. Kawabata
H. Akimune
H. Fujimura
H. Fujita
Y. Fujita
M. Fujiwara
K. Hara
K. Y. Hara
K. Hatanaka
T. Ishikawa
M. Itoh
J. Kamiya
S. Kishi
M. Nakamura
K. Nakanishi
T. Noro
H. Sakaguchi
Y. Shimbara
H. Takeda
A. Tamii
S. Terashima
H. Toyokawa
M. Uchida
H. Ueno
T. Wakasa
Y. Yasuda
H. P. Yoshida
M. Yosoi
12/19/2014--
05/01/2014
Upper bounds on the charge susceptibility of many-electron systems coupled to the quantized radiation field
We extend the Kubo-Kishi theorem concerning the charge susceptibility of the
Hubbard model in the following way: (i) The electron-photon interaction is
taken into account. (ii) Not only on-site but also general Coulomb repulsion is
considered.
Tadahiro Miyao
10/10/2017--
10/10/2017
Divisibility of the class numbers of imaginary quadratic fields
For a given odd integer $n>1$, we provide some families of imaginary
quadratic number fields of the form $\mathbb{Q}(\sqrt{x^2-t^n})$ whose ideal
class group has a subgroup isomorphic to $\mathbb{Z}/n\mathbb{Z}$.
Kalyan Chakraborty
Azizul Hoque
Yasuhiro Kishi
Prem Prakash Pandey
11/10/2003--
11/10/2003
Dielectric response of the interacting 1D spinless fermions with disorder
Dielectric responces of the one-dimentional electron system is investigated
numerically. We treat an interacting one-dimentional spinless fermion model
with disorder by using the Density Matrix Renormalization Group(DMRG) method
which is extended for nonuniform systems. We apply an electric field $E$ to the
system and calculate dielectric responces. Dielectric responce of the Mott
insulator and the Anderson insulator are calculated respectively. Steplike
behaviors in $P-E$ curve are obtained which corresponds to breakdown of the
insulating behavior. For the Mott insulator, the steps originate from
generation of kink-pairs. For the Anderson insulator on the other hand, the
origin of the steps is a crossing of the localized one particle energy levels.
We also treat random systems with interaction. From one parameter scaling
analysis of the susceptibility $\chi$, the metal-insulator transition in
attractively interacting region is confirmed and a phase diagram of the random
spinless fermion model is obtained.
Masato Kishi
Yasuhiro Hatsugai
04/13/2020--
04/13/2020
Non-Kolmogorov scaling for two-particle relative velocity in two-dimensional inverse energy-cascade turbulence
Herein,we numerically examine the relative dispersion of Lagrangian particle
pairs in two-dimensional inverse energy-cascade turbulence. Behind the
Richardson-Obukhov $t^3$ law of relative separation, we discover that the
second-order moment of the relative velocity have a temporal scaling exponent
different from the prediction based on the Kolmogorov's phenomenology. The
results also indicate that time evolution of the probability distribution
function of the relative velocity is self-similar. The findings are obtained by
enforcing Richardson-Obukhov law either by considering a special initial
separation or by conditional sampling. In particular, we demonstrate that the
conditional sampling removes the initial-separation dependence of the
statistics of the separation and relative velocity. Furthermore, we demonstrate
that the conditional statistics are robust with respect to the change in the
parameters involved, and that the number of the removed pairs from the sampling
decreases when the Reynolds number increases. We also discuss the insights
gained as a result of conditional sampling.
Tatsuro Kishi
Takeshi Matsumoto
Sadayoshi Toh
02/05/2019--
02/05/2019
Perturbative GAN: GAN with Perturbation Layers
Perturbative GAN, which replaces convolution layers of existing convolutional
GANs (DCGAN, WGAN-GP, BIGGAN, etc.) with perturbation layers that adds a fixed
noise mask, is proposed. Compared with the convolu-tional GANs, the number of
parameters to be trained is smaller, the convergence of training is faster, the
incep-tion score of generated images is higher, and the overall training cost
is reduced. Algorithmic generation of the noise masks is also proposed, with
which the training, as well as the generation, can be boosted with hardware
acceleration. Perturbative GAN is evaluated using con-ventional datasets
(CIFAR10, LSUN, ImageNet), both in the cases when a perturbation layer is
adopted only for Generators and when it is introduced to both Generator and
Discriminator.
Yuma Kishi
Tsutomu Ikegami
Shin-ichi O'uchi
Ryousei Takano
Wakana Nogami
Tomohiro Kudoh
03/30/2021--
03/30/2021
Graph kernels encoding features of all subgraphs by quantum superposition
Graph kernels are often used in bioinformatics and network applications to
measure the similarity between graphs; therefore, they may be used to construct
efficient graph classifiers. Many graph kernels have been developed thus far,
but to the best of our knowledge there is no existing graph kernel that
considers all subgraphs to measure similarity. We propose a novel graph kernel
that applies a quantum computer to measure the graph similarity taking all
subgraphs into account by fully exploiting the power of quantum superposition
to encode every subgraph into a feature. For the construction of the quantum
kernel, we develop an efficient protocol that removes the index information of
subgraphs encoded in the quantum state. We also prove that the quantum computer
requires less query complexity to construct the feature vector than the
classical sampler used to approximate the same vector. A detailed numerical
simulation of a bioinformatics problem is presented to demonstrate that, in
many cases, the proposed quantum kernel achieves better classification accuracy
than existing graph kernels.
Kaito Kishi
Takahiko Satoh
Rudy Raymond
Naoki Yamamoto
Yasubumi Sakakibara
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