13,899 research outputs found
A Tale of Two Portals: Testing Light, Hidden New Physics at Future Colliders
We investigate the prospects for producing new, light, hidden states at a
future collider in a Higgsed dark model, which we call the
Double Dark Portal model. The simultaneous presence of both vector and scalar
portal couplings immediately modifies the Standard Model Higgsstrahlung
channel, , at leading order in each coupling. In addition, each
portal leads to complementary signals which can be probed at direct and
indirect detection dark matter experiments. After accounting for current
constraints from LEP and LHC, we demonstrate that a future Higgs
factory will have unique and leading sensitivity to the two portal couplings by
studying a host of new production, decay, and radiative return processes.
Besides the possibility of exotic Higgs decays, we highlight the importance of
direct dark vector and dark scalar production at machines, whose
invisible decays can be tagged from the recoil mass method.Comment: 47 pages, 9 figures, 1 table. v2: references added, version matched
to JHE
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
Exploiting Sentence Embedding for Medical Question Answering
Despite the great success of word embedding, sentence embedding remains a
not-well-solved problem. In this paper, we present a supervised learning
framework to exploit sentence embedding for the medical question answering
task. The learning framework consists of two main parts: 1) a sentence
embedding producing module, and 2) a scoring module. The former is developed
with contextual self-attention and multi-scale techniques to encode a sentence
into an embedding tensor. This module is shortly called Contextual
self-Attention Multi-scale Sentence Embedding (CAMSE). The latter employs two
scoring strategies: Semantic Matching Scoring (SMS) and Semantic Association
Scoring (SAS). SMS measures similarity while SAS captures association between
sentence pairs: a medical question concatenated with a candidate choice, and a
piece of corresponding supportive evidence. The proposed framework is examined
by two Medical Question Answering(MedicalQA) datasets which are collected from
real-world applications: medical exam and clinical diagnosis based on
electronic medical records (EMR). The comparison results show that our proposed
framework achieved significant improvements compared to competitive baseline
approaches. Additionally, a series of controlled experiments are also conducted
to illustrate that the multi-scale strategy and the contextual self-attention
layer play important roles for producing effective sentence embedding, and the
two kinds of scoring strategies are highly complementary to each other for
question answering problems.Comment: 8 page
Structural and electronic properties of ScnOm (n=1~3, m=1~2n) clusters: Theoretical study using screened hybrid density functional theory
The structural and electronic properties of small scandium oxide clusters
ScnOm (n = 1 - 3, m = 1 - 2n) are systematically studied within the screened
hybrid density functional theory. It is found that the ground states of these
scandium oxide clusters can be obtained by the sequential oxidation of small
"core" scandium clusters. The fragmentation analysis demonstrates that the ScO,
Sc2O2, Sc2O3, Sc3O3, and Sc3O4 clusters are especially stable. Strong
hybridizations between O-2p and Sc-3d orbitals are found to be the most
significant character around the Fermi level. In comparison with standard
density functional theory calculations, we find that the screened hybrid
density functional theory can correct the wrong symmetries and yield more
precise description for the localized 3d electronic states of scandium.Comment: 8 figure
Kinetic behavior of the general modifier mechanism of Botts and Morales with non-equilibrium binding
In this paper, we perform a complete analysis of the kinetic behavior of the
general modifier mechanism of Botts and Morales in both equilibrium steady
states and non-equilibrium steady states (NESS). Enlightened by the
non-equilibrium theory of Markov chains, we introduce the net flux into
discussion and acquire an expression of product rate in NESS, which has clear
biophysical significance. Up till now, it is a general belief that being an
activator or an inhibitor is an intrinsic property of the modifier. However, we
reveal that this traditional point of view is based on the equilibrium
assumption. A modifier may no longer be an overall activator or inhibitor when
the reaction system is not in equilibrium. Based on the regulation of enzyme
activity by the modifier concentration, we classify the kinetic behavior of the
modifier into three categories, which are named hyperbolic behavior,
bell-shaped behavior, and switching behavior, respectively. We show that the
switching phenomenon, in which a modifier may convert between an activator and
an inhibitor when the modifier concentration varies, occurs only in NESS.
Effects of drugs on the Pgp ATPase activity, where drugs may convert from
activators to inhibitors with the increase of the drug concentration, are taken
as a typical example to demonstrate the occurrence of the switching phenomenon.Comment: 19 pages, 10 figure
Fair trade in insurance industry: Premium determination of Taiwan automobile insurance
This paper examines premium determination of voluntary automobile insurance policy and risk classification under a heavily regulated rating system in Taiwan. We investigate the distribution of actual premium and pure premium, based on unique data to test if premium reflect appropriate gender-age factor. The reasonableness of loading and the difference in driving exposure between policyholder and driver are investigated for three different
types of policy. An adjustment of gender-age premium coefficients is called for
Placebo Analgesia, Acupuncture and Sham Surgery
Invasive procedures, such as surgery and acupuncture, are likely better than the others in terms of eliciting placebo analgesia. Understanding how invasive procedures can elicit enhanced placebo responses may provide new insights into mechanisms underlying placebo analgesia. In this essay, it is argued that sensory, cognitive and emotional factors are major determinants of the magnitude of placebo analgesia. Sham surgery and acupuncture are good examples of placebo interventions, which generate robust placebo responses through simultaneously manipulating such three factors
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