31 research outputs found
T2M-GPT: Generating Human Motion from Textual Descriptions with Discrete Representations
In this work, we investigate a simple and must-known conditional generative
framework based on Vector Quantised-Variational AutoEncoder (VQ-VAE) and
Generative Pre-trained Transformer (GPT) for human motion generation from
textural descriptions. We show that a simple CNN-based VQ-VAE with commonly
used training recipes (EMA and Code Reset) allows us to obtain high-quality
discrete representations. For GPT, we incorporate a simple corruption strategy
during the training to alleviate training-testing discrepancy. Despite its
simplicity, our T2M-GPT shows better performance than competitive approaches,
including recent diffusion-based approaches. For example, on HumanML3D, which
is currently the largest dataset, we achieve comparable performance on the
consistency between text and generated motion (R-Precision), but with FID 0.116
largely outperforming MotionDiffuse of 0.630. Additionally, we conduct analyses
on HumanML3D and observe that the dataset size is a limitation of our approach.
Our work suggests that VQ-VAE still remains a competitive approach for human
motion generation.Comment: Accepted to CVPR 2023. Project page:
https://mael-zys.github.io/T2M-GPT
Minute-cadence Observations of the LAMOST Fields with the TMTS: III. Statistic Study of the Flare Stars from the First Two Years
Tsinghua University-Ma Huateng Telescopes for Survey (TMTS) aims to detect
fast-evolving transients in the Universe, which has led to the discovery of
thousands of short-period variables and eclipsing binaries since 2020. In this
paper, we present the observed properties of 125 flare stars identified by the
TMTS within the first two years, with an attempt to constrain their eruption
physics. As expected, most of these flares were recorded in late-type red stars
with > 2.0 mag, however, the flares associated with
bluer stars tend to be on average more energetic and have broader profiles. The
peak flux (F_peak) of the flare is found to depend strongly on the equivalent
duration (ED) of the energy release, i.e., , which is consistent with results derived from the Kepler
and Evryscope samples. This relation is likely related to the magnetic loop
emission, while -- for the more popular non-thermal electron heating model -- a
specific time evolution may be required to generate this relation. We notice
that flares produced by hotter stars have a flatter relation compared to that from cooler stars. This is related to the
statistical discrepancy in light-curve shape of flare events with different
colors. In spectra from LAMOST, we find that flare stars have apparently
stronger H alpha emission than inactive stars, especially at the low
temperature end, suggesting that chromospheric activity plays an important role
in producing flares. On the other hand, the subclass having frequent flares are
found to show H alpha emission of similar strength in their spectra to that
recorded with only a single flare but similar effective temperature, implying
that the chromospheric activity may not be the only trigger for eruptions.Comment: 17 pages, 15 figures, 2 tables, refereed version. For associated data
files, see https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/523/219
Properties and Asteroseismological analysis of a new ZZ ceti discovered by TMTS
Tsinghua university-Ma Huateng Telescope for Survey (TMTS) aims to discover
rapidly evolving transients by monitoring the northern sky. The TMTS catalog is
cross-matched with the white dwarf (WD) catalog of Gaia EDR3, and light curves
of more than a thousand WD candidates are obtained so far. Among them, the WD
TMTS J23450729+5813146 (hereafter J2345) is one interesting common source.
Based on the light curves from the TMTS and follow-up photometric observations,
periods of 967.113 s, 973.734 s, 881.525 s, 843.458 s, 806.916 s and 678.273 s
are identified. In addition, the TESS observations suggest a 3.39 h period but
this can be attributed to the rotation of a comoving M dwarf located within 3".
The spectroscopic observation indicates that this WD is DA type with Teff =
11778+/-617K,log g = 8.38+/-0.31,mass=0.84+/-0.20Msun and age=0.704+/-0.377
Gyrs. Asteroseismological analysis reveals a global best-fit solution of Teff
=12110+/-10K and mass=0.760+/-0.005Msun,consistent with the spectral fitting
results, and Oxygen and Carbon abundances in the core center are 0.73 and 0.27,
respectively. The distance derived from the intrinsic luminosity given by
asteroseismology is 93 parsec, which is in agreement with the distance of 98
parsec from Gaia DR3. Additionally, kinematic study shows that this WD is
likely a thick disk star. The mass of its zero-age main-sequence mass is
estimated to be 3.08 Msun and has a main-sequence plus cooling age of roughly
900 Myrs.Comment: 10 pages, 10 figures, accepted for publication in MNRA
Vitamin D and cause-specific vascular disease and mortality:a Mendelian randomisation study involving 99,012 Chinese and 106,911 European adults
Modification of long range order in germanate glass by ultra fast laser
A novel order–disorder phase transition in glasses via ultra fast laser irradiation is first time reported. The Raman spectra of modified region is highly dependent on the polarization of probe beam, indicating the bond orientation at the outer structure of modified region is no longer isotropic and a long-range-order is induced which could be analogue with liquid crystals. The ordered glass phase is not expected from inorganic materials and further investigation is needed
One-Pot and Surfactant-Free Synthesis of Ultrafine PtSn Nanoparticles Supported on Onion-Like Nanocarbons Toward Efficient Methanol and Ethylene Glycol Oxidation Reactions
Square-shape distribution of ZnO crystals in glass by using a spatial light modulator
We report on square-shape distribution of ZnO crystals in glass by simultaneous femtosecond laser irradiation at multiple spots with the application of a spatial light modulator. Raman spectra and Raman mapping were used to characterize the formation of ZnO crystals and distribution of ZnO crystals, respectively. The shapes of the laser-modified region and the distribution of ZnO crystals were compared between the cases of one spot irradiation and multiple spot irradiation. The elemental distributions of the laser-modified region were investigated by an Electron Probe Microanalyzer
Confocal Raman imaging of femtosecond laser induced microstructures in germanate glasses
Space selective reduction of europium ions via SrF2 crystals induced by high repetition rate femtosecond laser
We report using high repetition rate near-infrared femtoseond laser to reduce Eu3+ into Eu2+ inside oxyfluoride glass. SrF2 crystal was space-selectively precipitated with the irradiation of femtosecond laser and we successfully realized the reduction of Eu ions, confirmed with the observation of blue emission of Eu2+ at laser irradiated spots. The mechanism of the reduction is different from those in previous work which is based on the active electron and holes created by the infrared laser pulse. This work could extend selection of host composition of Eu-doped glass for 3D optical information storage