166 research outputs found
Logical Message Passing Networks with One-hop Inference on Atomic Formulas
Complex Query Answering (CQA) over Knowledge Graphs (KGs) has attracted a lot
of attention to potentially support many applications. Given that KGs are
usually incomplete, neural models are proposed to answer logical queries by
parameterizing set operators with complex neural networks. However, such
methods usually train neural set operators with a large number of entity and
relation embeddings from zero, where whether and how the embeddings or the
neural set operators contribute to the performance remains not clear. In this
paper, we propose a simple framework for complex query answering that
decomposes the KG embeddings from neural set operators. We propose to represent
the complex queries in the query graph. On top of the query graph, we propose
the Logical Message Passing Neural Network (LMPNN) that connects the
\textit{local} one-hop inferences on atomic formulas to the \textit{global}
logical reasoning for complex query answering. We leverage existing effective
KG embeddings to conduct one-hop inferences on atomic formulas, the results of
which are regarded as the messages passed in LMPNN. The reasoning process over
the overall logical formulas is turned into the forward pass of LMPNN that
incrementally aggregates local information to predict the answers' embeddings
finally. The complex logical inference across different types of queries will
then be learned from training examples based on the LMPNN architecture.
Theoretically, our query-graph representation is more general than the
prevailing operator-tree formulation, so our approach applies to a broader
range of complex KG queries. Empirically, our approach yields a new
state-of-the-art neural CQA model. Our research bridges the gap between complex
KG query answering tasks and the long-standing achievements of knowledge graph
representation learning.Comment: Accepted by ICLR 2023. 20 pages, 4 figures, and 9 table
Complex Hyperbolic Knowledge Graph Embeddings with Fast Fourier Transform
The choice of geometric space for knowledge graph (KG) embeddings can have
significant effects on the performance of KG completion tasks. The hyperbolic
geometry has been shown to capture the hierarchical patterns due to its
tree-like metrics, which addressed the limitations of the Euclidean embedding
models. Recent explorations of the complex hyperbolic geometry further improved
the hyperbolic embeddings for capturing a variety of hierarchical structures.
However, the performance of the hyperbolic KG embedding models for
non-transitive relations is still unpromising, while the complex hyperbolic
embeddings do not deal with multi-relations. This paper aims to utilize the
representation capacity of the complex hyperbolic geometry in multi-relational
KG embeddings. To apply the geometric transformations which account for
different relations and the attention mechanism in the complex hyperbolic
space, we propose to use the fast Fourier transform (FFT) as the conversion
between the real and complex hyperbolic space. Constructing the attention-based
transformations in the complex space is very challenging, while the proposed
Fourier transform-based complex hyperbolic approaches provide a simple and
effective solution. Experimental results show that our methods outperform the
baselines, including the Euclidean and the real hyperbolic embedding models.Comment: Aceepted by the 2022 Conference on Empirical Methods in Natural
Language Processing (EMNLP22
Extremal Optimization of Graph Partitioning at the Percolation Threshold
The benefits of a recently proposed method to approximate hard optimization
problems are demonstrated on the graph partitioning problem. The performance of
this new method, called Extremal Optimization, is compared to Simulated
Annealing in extensive numerical simulations. While generally a complex
(NP-hard) problem, the optimization of the graph partitions is particularly
difficult for sparse graphs with average connectivities near the percolation
threshold. At this threshold, the relative error of Simulated Annealing for
large graphs is found to diverge relative to Extremal Optimization at equalized
runtime. On the other hand, Extremal Optimization, based on the extremal
dynamics of self-organized critical systems, reproduces known results about
optimal partitions at this critical point quite well.Comment: 7 pages, RevTex, 9 ps-figures included, as to appear in Journal of
Physics
TILFA: A Unified Framework for Text, Image, and Layout Fusion in Argument Mining
A main goal of Argument Mining (AM) is to analyze an author's stance. Unlike
previous AM datasets focusing only on text, the shared task at the 10th
Workshop on Argument Mining introduces a dataset including both text and
images. Importantly, these images contain both visual elements and optical
characters. Our new framework, TILFA (A Unified Framework for Text, Image, and
Layout Fusion in Argument Mining), is designed to handle this mixed data. It
excels at not only understanding text but also detecting optical characters and
recognizing layout details in images. Our model significantly outperforms
existing baselines, earning our team, KnowComp, the 1st place in the
leaderboard of Argumentative Stance Classification subtask in this shared task.Comment: Accepted to the 10th Workshop on Argument Mining, co-located with
EMNLP 202
Brief Overview of Bioinformatics Activities in Singapore
10.1371/journal.pcbi.1000508PLoS Computational Biology5
Machine Learning-Driven Multiscale Modeling: Bridging the Scales with a Next-Generation Simulation Infrastructure
Interdependence across time and length scales is common in biology, where atomic interactions can impact larger-scale phenomenon. Such dependence is especially true for a well-known cancer signaling pathway, where the membrane-bound RAS protein binds an effector protein called RAF. To capture the driving forces that bring RAS and RAF (represented as two domains, RBD and CRD) together on the plasma membrane, simulations with the ability to calculate atomic detail while having long time and large length- scales are needed. The Multiscale Machine-Learned Modeling Infrastructure (MuMMI) is able to resolve RAS/RAF protein-membrane interactions that identify specific lipid-protein fingerprints that enhance protein orientations viable for effector binding. MuMMI is a fully automated, ensemble-based multiscale approach connecting three resolution scales: (1) the coarsest scale is a continuum model able to simulate milliseconds of time for a 1 μm2 membrane, (2) the middle scale is a coarse-grained (CG) Martini bead model to explore protein-lipid interactions, and (3) the finest scale is an all-atom (AA) model capturing specific interactions between lipids and proteins. MuMMI dynamically couples adjacent scales in a pairwise manner using machine learning (ML). The dynamic coupling allows for better sampling of the refined scale from the adjacent coarse scale (forward) and on-the-fly feedback to improve the fidelity of the coarser scale from the adjacent refined scale (backward). MuMMI operates efficiently at any scale, from a few compute nodes to the largest supercomputers in the world, and is generalizable to simulate different systems. As computing resources continue to increase and multiscale methods continue to advance, fully automated multiscale simulations (like MuMMI) will be commonly used to address complex science questions
Identification and validation of clinical predictors for the risk of neurological involvement in children with hand, foot, and mouth disease in Sarawak
Background: Human enterovirus 71 (HEV71) can cause Hand, foot, and mouth disease (HFMD) with neurological
complications, which may rapidly progress to fulminant cardiorespiratory failure, and death. Early recognition of children
at risk is the key to reduce acute mortality and morbidity.
Methods: We examined data collected through a prospective clinical study of HFMD conducted between 2000 and 2006
that included 3 distinct outbreaks of HEV71 to identify risk factors associated with neurological involvement in children
with HFMD.
Results: Total duration of fever ≥ 3 days, peak temperature ≥ 38.5°C and history of lethargy were identified as
independent risk factors for neurological involvement (evident by CSF pleocytosis) in the analysis of 725 children
admitted during the first phase of the study. When they were validated in the second phase of the study, two or more
(≥ 2) risk factors were present in 162 (65%) of 250 children with CSF pleocytosis compared with 56 (30%) of 186 children
with no CSF pleocytosis (OR 4.27, 95% CI2.79–6.56, p < 0.0001). The usefulness of the three risk factors in identifying
children with CSF pleocytosis on hospital admission during the second phase of the study was also tested. Peak
temperature ≥ 38.5°C and history of lethargy had the sensitivity, specificity, positive predictive value (PPV) and negative
predictive value (NPV) of 28%(48/174), 89%(125/140), 76%(48/63) and 50%(125/251), respectively in predicting CSF
pleocytosis in children that were seen within the first 2 days of febrile illness. For those presented on the 3rd or later day
of febrile illness, the sensitivity, specificity, PPV and NPV of ≥ 2 risk factors predictive of CSF pleocytosis were 75%(57/
76), 59%(27/46), 75%(57/76) and 59%(27/46), respectively.
Conclusion: Three readily elicited clinical risk factors were identified to help detect children at risk of neurological
involvement. These risk factors may serve as a guide to clinicians to decide the need for hospitalization and further
investigation, including cerebrospinal fluid examination, and close monitoring for disease progression in children with
HFMD
- …