5,215 research outputs found
WSDMS: Debunk Fake News via Weakly Supervised Detection of Misinforming Sentences with Contextualized Social Wisdom
In recent years, we witness the explosion of false and unconfirmed
information (i.e., rumors) that went viral on social media and shocked the
public. Rumors can trigger versatile, mostly controversial stance expressions
among social media users. Rumor verification and stance detection are different
yet relevant tasks. Fake news debunking primarily focuses on determining the
truthfulness of news articles, which oversimplifies the issue as fake news
often combines elements of both truth and falsehood. Thus, it becomes crucial
to identify specific instances of misinformation within the articles. In this
research, we investigate a novel task in the field of fake news debunking,
which involves detecting sentence-level misinformation. One of the major
challenges in this task is the absence of a training dataset with
sentence-level annotations regarding veracity. Inspired by the Multiple
Instance Learning (MIL) approach, we propose a model called Weakly Supervised
Detection of Misinforming Sentences (WSDMS). This model only requires bag-level
labels for training but is capable of inferring both sentence-level
misinformation and article-level veracity, aided by relevant social media
conversations that are attentively contextualized with news sentences. We
evaluate WSDMS on three real-world benchmarks and demonstrate that it
outperforms existing state-of-the-art baselines in debunking fake news at both
the sentence and article levels
Heterogeneous Graph Reasoning for Fact Checking over Texts and Tables
Fact checking aims to predict claim veracity by reasoning over multiple
evidence pieces. It usually involves evidence retrieval and veracity reasoning.
In this paper, we focus on the latter, reasoning over unstructured text and
structured table information. Previous works have primarily relied on
fine-tuning pretrained language models or training homogeneous-graph-based
models. Despite their effectiveness, we argue that they fail to explore the
rich semantic information underlying the evidence with different structures. To
address this, we propose a novel word-level Heterogeneous-graph-based model for
Fact Checking over unstructured and structured information, namely HeterFC. Our
approach leverages a heterogeneous evidence graph, with words as nodes and
thoughtfully designed edges representing different evidence properties. We
perform information propagation via a relational graph neural network,
facilitating interactions between claims and evidence. An attention-based
method is utilized to integrate information, combined with a language model for
generating predictions. We introduce a multitask loss function to account for
potential inaccuracies in evidence retrieval. Comprehensive experiments on the
large fact checking dataset FEVEROUS demonstrate the effectiveness of HeterFC.
Code will be released at: https://github.com/Deno-V/HeterFC.Comment: Accepted by 38th Association for the Advancement of Artificial
Intelligence, AAA
Towards a complexity theory for the congested clique
The congested clique model of distributed computing has been receiving
attention as a model for densely connected distributed systems. While there has
been significant progress on the side of upper bounds, we have very little in
terms of lower bounds for the congested clique; indeed, it is now know that
proving explicit congested clique lower bounds is as difficult as proving
circuit lower bounds.
In this work, we use various more traditional complexity-theoretic tools to
build a clearer picture of the complexity landscape of the congested clique:
-- Nondeterminism and beyond: We introduce the nondeterministic congested
clique model (analogous to NP) and show that there is a natural canonical
problem family that captures all problems solvable in constant time with
nondeterministic algorithms. We further generalise these notions by introducing
the constant-round decision hierarchy (analogous to the polynomial hierarchy).
-- Non-constructive lower bounds: We lift the prior non-uniform counting
arguments to a general technique for proving non-constructive uniform lower
bounds for the congested clique. In particular, we prove a time hierarchy
theorem for the congested clique, showing that there are decision problems of
essentially all complexities, both in the deterministic and nondeterministic
settings.
-- Fine-grained complexity: We map out relationships between various natural
problems in the congested clique model, arguing that a reduction-based
complexity theory currently gives us a fairly good picture of the complexity
landscape of the congested clique
WarpNet: Weakly Supervised Matching for Single-view Reconstruction
We present an approach to matching images of objects in fine-grained datasets
without using part annotations, with an application to the challenging problem
of weakly supervised single-view reconstruction. This is in contrast to prior
works that require part annotations, since matching objects across class and
pose variations is challenging with appearance features alone. We overcome this
challenge through a novel deep learning architecture, WarpNet, that aligns an
object in one image with a different object in another. We exploit the
structure of the fine-grained dataset to create artificial data for training
this network in an unsupervised-discriminative learning approach. The output of
the network acts as a spatial prior that allows generalization at test time to
match real images across variations in appearance, viewpoint and articulation.
On the CUB-200-2011 dataset of bird categories, we improve the AP over an
appearance-only network by 13.6%. We further demonstrate that our WarpNet
matches, together with the structure of fine-grained datasets, allow
single-view reconstructions with quality comparable to using annotated point
correspondences.Comment: to appear in IEEE Conference on Computer Vision and Pattern
Recognition (CVPR) 201
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