124 research outputs found
Semantic Image Synthesis via Adversarial Learning
In this paper, we propose a way of synthesizing realistic images directly
with natural language description, which has many useful applications, e.g.
intelligent image manipulation. We attempt to accomplish such synthesis: given
a source image and a target text description, our model synthesizes images to
meet two requirements: 1) being realistic while matching the target text
description; 2) maintaining other image features that are irrelevant to the
text description. The model should be able to disentangle the semantic
information from the two modalities (image and text), and generate new images
from the combined semantics. To achieve this, we proposed an end-to-end neural
architecture that leverages adversarial learning to automatically learn
implicit loss functions, which are optimized to fulfill the aforementioned two
requirements. We have evaluated our model by conducting experiments on
Caltech-200 bird dataset and Oxford-102 flower dataset, and have demonstrated
that our model is capable of synthesizing realistic images that match the given
descriptions, while still maintain other features of original images.Comment: Accepted to ICCV 201
Thermoelectric effect in high mobility single layer epitaxial graphene
The thermoelectric response of high mobility single layer epitaxial graphene
on silicon carbide substrates as a function of temperature and magnetic field
have been investigated. For the temperature dependence of the thermopower, a
strong deviation from the Mott relation has been observed even when the carrier
density is high, which reflects the importance of the screening effect. In the
quantum Hall regime, the amplitude of the thermopower peaks is lower than a
quantum value predicted by theories, despite the high mobility of the sample. A
systematic reduction of the amplitude with decreasing temperature suggests that
the suppression of the thermopower is intrinsic to Dirac electrons in graphene.Comment: 5 pages, 4 figure
Half integer quantum Hall effect in high mobility single layer epitaxial graphene
The quantum Hall effect, with a Berry's phase of is demonstrated here
on a single graphene layer grown on the C-face of 4H silicon carbide. The
mobility is 20,000 cm/Vs at 4 K and ~15,000 cm/Vs
at 300 K despite contamination and substrate steps. This is comparable to the
best exfoliated graphene flakes on SiO and an order of magnitude larger
than Si-face epitaxial graphene monolayers. These and other properties indicate
that C-face epitaxial graphene is a viable platform for graphene-based
electronics.Comment: Some modifications in the text and figures, 7 pages, 2 figure
Overcoming Language Priors in Visual Question Answering via Distinguishing Superficially Similar Instances
Despite the great progress of Visual Question Answering (VQA), current VQA
models heavily rely on the superficial correlation between the question type
and its corresponding frequent answers (i.e., language priors) to make
predictions, without really understanding the input. In this work, we define
the training instances with the same question type but different answers as
\textit{superficially similar instances}, and attribute the language priors to
the confusion of VQA model on such instances. To solve this problem, we propose
a novel training framework that explicitly encourages the VQA model to
distinguish between the superficially similar instances. Specifically, for each
training instance, we first construct a set that contains its superficially
similar counterparts. Then we exploit the proposed distinguishing module to
increase the distance between the instance and its counterparts in the answer
space. In this way, the VQA model is forced to further focus on the other parts
of the input beyond the question type, which helps to overcome the language
priors. Experimental results show that our method achieves the state-of-the-art
performance on VQA-CP v2. Codes are available at
\href{https://github.com/wyk-nku/Distinguishing-VQA.git}{Distinguishing-VQA}.Comment: Published in COLING 202
Uncertainty-Aware Unlikelihood Learning Improves Generative Aspect Sentiment Quad Prediction
Recently, aspect sentiment quad prediction has received widespread attention
in the field of aspect-based sentiment analysis. Existing studies extract
quadruplets via pre-trained generative language models to paraphrase the
original sentence into a templated target sequence. However, previous works
only focus on what to generate but ignore what not to generate. We argue that
considering the negative samples also leads to potential benefits. In this
work, we propose a template-agnostic method to control the token-level
generation, which boosts original learning and reduces mistakes simultaneously.
Specifically, we introduce Monte Carlo dropout to understand the built-in
uncertainty of pre-trained language models, acquiring the noises and errors. We
further propose marginalized unlikelihood learning to suppress the
uncertainty-aware mistake tokens. Finally, we introduce minimization entropy to
balance the effects of marginalized unlikelihood learning. Extensive
experiments on four public datasets demonstrate the effectiveness of our
approach on various generation templates1
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