513 research outputs found
SuperUDF: Self-supervised UDF Estimation for Surface Reconstruction
Learning-based surface reconstruction based on unsigned distance functions
(UDF) has many advantages such as handling open surfaces. We propose SuperUDF,
a self-supervised UDF learning which exploits a learned geometry prior for
efficient training and a novel regularization for robustness to sparse
sampling. The core idea of SuperUDF draws inspiration from the classical
surface approximation operator of locally optimal projection (LOP). The key
insight is that if the UDF is estimated correctly, the 3D points should be
locally projected onto the underlying surface following the gradient of the
UDF. Based on that, a number of inductive biases on UDF geometry and a
pre-learned geometry prior are devised to learn UDF estimation efficiently. A
novel regularization loss is proposed to make SuperUDF robust to sparse
sampling. Furthermore, we also contribute a learning-based mesh extraction from
the estimated UDFs. Extensive evaluations demonstrate that SuperUDF outperforms
the state of the arts on several public datasets in terms of both quality and
efficiency. Code url is https://github.com/THHHomas/SuperUDF
Dynamic and Thermodynamic Stability of Charged Perfect Fluid Stars
We perform a thorough analysis of the dynamic and thermodynamic stability for
the charged perfect fluid star by applying the Wald formalism to the Lagrangian
formulation of Einstein-Maxwell-charged fluid system. As a result, we find that
neither the presence of the additional electromagnetic field nor the Lorentz
force experienced by the charged fluid makes any obstruction to the key steps
towards the previous results obtained for the neutral perfect fluid star.
Therefore, the criterion for the dynamic stability of our charged star in
dynamic equilibrium within the symplectic complement of the trivial
perturbaions with the ADM -momentum unchanged is given by the non-negativity
of the canonical energy associated with the timelike Killing field, where it is
further shown for both non-axisymmetric and axisymmetric perturbations that the
dynamic stability against these restricted perturbations also implies the
dynamic stability against more generic perturbations. On the other hand, the
necessary condition for the thermodynamic stability of our charged star in
thermodynamic equilibrium is given by the positivity of the canonical energy of
all the linear on-shell perturbations with the ADM angular momentum unchanged
in the comoving frame, which is equivalent to the positivity of the canonical
energy associated with the timelike Killing field when restricted onto the
axisymmetric perturbations. As a by-product, we further establish the
equivalence of the dynamic and thermodynamic stability with respect to the
spherically symmetric perturbations of the static, spherically symmetric
isentropic charged star.Comment: 20 pages, 1 figur
A convenient tandem one-pot synthesis of donor-acceptor-type triphenylene 2,3-dicarboxylic esters from diarylacetylene
A tandem one-pot method for the direct synthesis of polysubstituted triphenylene 2,3-dicarboxylic esters with different substitution patterns was developed by enyne metathesis of diarylacetylene, followed by Diels–Alder, aromatization and a cyclization cascade
ScQ cloud quantum computation for generating Greenberger-Horne-Zeilinger states of up to 10 qubits
We introduce an online for public quantum computation platform, named as ScQ,
based on a 1D array of 10-qubit superconducting processor. Single qubit
rotation gates can be performed on each qubit. Controlled-NOT (CNOT) gates
between nearest-neighbor sites on the 1D array of 10 qubits are available. We
show online preparation and verification of Greenberger-Horne-Zeilinger (GHZ)
states of up to 10 qubits by this platform, for all possible blocks of qubits
in the chain. Both graphic interface and the quantum assembly language methods
are presented to achieve the above tasks, which rely on a parameter scanning
feature implemented on ScQ. Performance of this quantum computation platform,
such as fidelities of the logic gates and details of the superconducting
device, are presented
Recommended from our members
Genomic Variation in Rice: Genesis of Highly Polymorphic Linkage Blocks during Domestication
Genomic regions that are unusually divergent between closely related species or racial groups can be particularly informative about the process of speciation or the operation of natural selection. The two sequenced genomes of cultivated Asian rice, Oryza sativa, reveal that at least 6% of the genomes are unusually divergent. Sequencing of ten unlinked loci from the highly divergent regions consistently identified two highly divergent haplotypes with each locus in nearly complete linkage disequilibrium among 25 O. sativa cultivars and 35 lines from six wild species. The existence of two highly divergent haplotypes in high divergence regions in species from all geographical areas (Africa, Asia, and Oceania) was in contrast to the low polymorphism and low linkage disequilibrium that were observed in other parts of the genome, represented by ten reference loci. While several natural processes are likely to contribute to this pattern of genomic variation, domestication may have greatly exaggerated the trend. In this hypothesis, divergent haplotypes that were adapted to different geographical and ecological environments migrated along with humans during the development of domesticated varieties. If true, these high divergence regions of the genome would be enriched for loci that contribute to the enormous range of phenotypic variation observed among domesticated breeds.</p
- …