4,305 research outputs found
Talking Face Generation by Adversarially Disentangled Audio-Visual Representation
Talking face generation aims to synthesize a sequence of face images that
correspond to a clip of speech. This is a challenging task because face
appearance variation and semantics of speech are coupled together in the subtle
movements of the talking face regions. Existing works either construct specific
face appearance model on specific subjects or model the transformation between
lip motion and speech. In this work, we integrate both aspects and enable
arbitrary-subject talking face generation by learning disentangled audio-visual
representation. We find that the talking face sequence is actually a
composition of both subject-related information and speech-related information.
These two spaces are then explicitly disentangled through a novel
associative-and-adversarial training process. This disentangled representation
has an advantage where both audio and video can serve as inputs for generation.
Extensive experiments show that the proposed approach generates realistic
talking face sequences on arbitrary subjects with much clearer lip motion
patterns than previous work. We also demonstrate the learned audio-visual
representation is extremely useful for the tasks of automatic lip reading and
audio-video retrieval.Comment: AAAI Conference on Artificial Intelligence (AAAI 2019) Oral
Presentation. Code, models, and video results are available on our webpage:
https://liuziwei7.github.io/projects/TalkingFace.htm
Calculations of optical rotation: Influence of molecular structure
Ab initio Hartree-Fock (HF) method and Density Functional Theory (DFT) were used to calculate the optical rotation of 26 chiral compounds. The effects of theory and basis sets used for calculation, solvents influence on the geometry and values of calculated optical rotation were all discussed. The polarizable continuum model, included in the calculation, did not improve the accuracy effectively, but it was superior to γs. Optical rotation of five or sixmembered of cyclic compound has been calculated and 17 pyrrolidine or piperidine derivatives which were calculated by HF and DFT methods gave acceptable predictions. The nitrogen atom affects the calculation results dramatically, and it is necessary in the molecular structure in order to get an accurate computation result. Namely, when the nitrogen atom was substituted by oxygen atom in the ring, the calculation result deteriorated
Uncertainty and bias of cosmology and astrophysical population model from statistical dark sirens
Gravitational-wave (GW) radiation from a coalescing compact binary is a
standard siren as the luminosity distance of each event can be directly
measured from the amplitude of the signal. One possibility to constrain
cosmology using the GW siren is to perform statistical inference on a
population of binary black hole (BBH) events. In essence, this statistical
method can be viewed as follows. We can modify the shape of the distribution of
observed BBH events by changing cosmological parameters until it eventually
matches the distribution constructed from an astrophysical population model,
thereby allowing us to determine the cosmological parameters. In this work, we
derive the Cram\'er-Rao bound for both cosmological parameters and those
governing the astrophysical population model from this statistical dark siren
method by examining the Fisher information contained in the event distribution.
Our study provides analytical insights and enables fast yet accurate
estimations of the statistical accuracy of dark siren cosmology. Furthermore,
we consider the bias in cosmology due to unmodeled substructures in the merger
rate and the mass distribution. We find a deviation in the astrophysical
model can lead to a more than error in the Hubble constant. This could
limit the accuracy of dark siren cosmology when there are more than BBH
events detected.Comment: 15 pages, 7 figures, to be submitted to Ap
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