178 research outputs found
Point Cloud Denoising and Outlier Detection with Local Geometric Structure by Dynamic Graph CNN
The digitalization of society is rapidly developing toward the realization of
the digital twin and metaverse. In particular, point clouds are attracting
attention as a media format for 3D space. Point cloud data is contaminated with
noise and outliers due to measurement errors. Therefore, denoising and outlier
detection are necessary for point cloud processing. Among them, PointCleanNet
is an effective method for point cloud denoising and outlier detection.
However, it does not consider the local geometric structure of the patch. We
solve this problem by applying two types of graph convolutional layer designed
based on the Dynamic Graph CNN. Experimental results show that the proposed
methods outperform the conventional method in AUPR, which indicates outlier
detection accuracy, and Chamfer Distance, which indicates denoising accuracy.Comment: 2023 IEEE 12th Global Conference on Consumer Electronics (GCCE 2023
A Concise Asymmetric Total Synthesis of (+)-Epilupinine
Asymmetric total synthesis of (+)-epilupinine was achieved in just 3 steps using only commercially available common reagents. The total synthesis involved alkylations of N-nosylamide, ozone oxidation, and sequential reactions of the removal of the nosyl group, intramolecular dehydrative condensation, intramolecular Mannich reaction catalyzed by L-proline, and a reduction
Real-time Trading System based on Selections of Potentially Profitable, Uncorrelated, and Balanced Stocks by NP-hard Combinatorial Optimization
Financial portfolio construction problems are often formulated as quadratic
and discrete (combinatorial) optimization that belong to the nondeterministic
polynomial time (NP)-hard class in computational complexity theory. Ising
machines are hardware devices that work in quantum-mechanical/quantum-inspired
principles for quickly solving NP-hard optimization problems, which potentially
enable making trading decisions based on NP-hard optimization in the time
constraints for high-speed trading strategies. Here we report a real-time stock
trading system that determines long(buying)/short(selling) positions through
NP-hard portfolio optimization for improving the Sharpe ratio using an embedded
Ising machine based on a quantum-inspired algorithm called simulated
bifurcation. The Ising machine selects a balanced (delta-neutral) group of
stocks from an -stock universe according to an objective function involving
maximizing instantaneous expected returns defined as deviations from
volume-weighted average prices and minimizing the summation of statistical
correlation factors (for diversification). It has been demonstrated in the
Tokyo Stock Exchange that the trading strategy based on NP-hard portfolio
optimization for =128 is executable with the FPGA (field-programmable gate
array)-based trading system with a response latency of 164 s.Comment: 12 pages, 5 figures. arXiv admin note: text overlap with
arXiv:2307.0592
VQE-generated Quantum Circuit Dataset for Machine Learning
Quantum machine learning has the potential to computationally outperform
classical machine learning, but it is not yet clear whether it will actually be
valuable for practical problems. While some artificial scenarios have shown
that certain quantum machine learning techniques may be advantageous compared
to their classical counterpart, it is unlikely that quantum machine learning
will outclass traditional methods on popular classical datasets such as MNIST.
In contrast, dealing with quantum data, such as quantum states or circuits, may
be the task where we can benefit from quantum methods. Therefore, it is
important to develop practically meaningful quantum datasets for which we
expect quantum methods to be superior. In this paper, we propose a machine
learning task that is likely to soon arise in the real world: clustering and
classification of quantum circuits. We provide a dataset of quantum circuits
optimized by the variational quantum eigensolver. We utilized six common types
of Hamiltonians in condensed matter physics, with a range of 4 to 16 qubits,
and applied ten different ans\"{a}tze with varying depths (ranging from 3 to
32) to generate a quantum circuit dataset of six distinct classes, each
containing 300 samples. We show that this dataset can be easily learned using
quantum methods. In particular, we demonstrate a successful classification of
our dataset using real 4-qubit devices available through IBMQ. By providing a
setting and an elementary dataset where quantum machine learning is expected to
be beneficial, we hope to encourage and ease the advancement of the field.Comment: 9 pages, 6figure
Total synthesis of palauâamine
Palauâamine has received a great deal of attention in the past two decades as an attractive synthetic target by virtue of its intriguing molecular architecture and significant immunosuppressive activity. Here we report the total synthesis of palauâamine characterized by the construction of an ABDE tetracyclic ring core including a trans-bicylo[3.3.0]octane skeleton at a middle stage of total synthesis. The ABDE tetracyclic ring core is constructed by a cascade reaction of a cleavage of the NâN bond, including simultaneous formation of imine, the addition of amide anion to the resulting imine (D-ring formation) and the condensation of pyrrole with methyl ester (B-ring formation) in a single step. The synthetic palauâamine is confirmed to exhibit excellent immunosuppressive activity. The present synthetic route has the potential to help elucidate a pharmacophore as well as the mechanistic details of immunosuppressive activity
Observation of band crossings protected by nonsymmorphic symmetry in the layered ternary telluride Ta3SiTe6
We have performed angle-resolved photoemission spectroscopy of layered
ternary telluride Ta3SiTe6 which is predicted to host nodal lines associated
with nonsymmorphic crystal symmetry. We found that the energy bands in the
valence-band region show Dirac-like dispersions which present a band degeneracy
at the R point of the bulk orthorhombic Brillouin zone. This band degeneracy
extends one-dimensionally along the whole SR high-symmetry line, forming the
nodal lines protected by the glide mirror symmetry of the crystal. We also
observed a small band splitting near EF which supports the existence of
hourglass-type dispersions predicted by the calculation. The present results
provide an excellent opportunity to investigate the interplay between exotic
nodal fermions and nonsymmorphic crystal symmetry.Comment: 6 pages, 4 figure
Observation of a Dirac nodal line in AlB2
We have performed angle-resolved photoemission spectroscopy of AlB2 which is
isostructural to high-temperature superconductor MgB2. Using soft-x-ray
photons, we accurately determined the three-dimensional bulk band structure and
found a highly anisotropic Dirac-cone band at the K point in the bulk hexagonal
Brillouin zone. This band disperses downward on approaching the H point while
keeping its degeneracy at the Dirac point, producing a characteristic Dirac
nodal line along the KH line. We also found that the band structure of AlB2 is
regarded as a heavily electron-doped version of MgB2 and is therefore well
suited for fully visualizing the predicted Dirac nodal line. The present
results suggest that (Al,Mg)B2 system is a promising platform for studying the
interplay among Dirac nodal line, carrier doping, and possible topological
superconducting properties.Comment: 6 pages, 3 figure
Development of 1,3a,6a-triazapentalene-labeled enterobactin as a fluorescence quenching sensor of iron ion
1,3a,6a-Triazapentalene (TAP)-labeled enterobactin was developed as an iron ion sensor. 3-Acetylated-TAP was successfully introduced to the catechol ring of enterobactin, a well-recognized siderophore secreted by various Gram-negative bacteria. The fluorescence of TAPlabeled enterobactin decreased gradually as the amount of Fe3+ ion as an additive was increased, and 1.2 equiv of Fe3+ ion completely quenched the fluorescence. In clear contrast, when other metal ions were used, the fluorescence of TAP-labeled enterobactin remained even at 5.0 equiv
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