610 research outputs found
Learning Joint 2D & 3D Diffusion Models for Complete Molecule Generation
Designing new molecules is essential for drug discovery and material science.
Recently, deep generative models that aim to model molecule distribution have
made promising progress in narrowing down the chemical research space and
generating high-fidelity molecules. However, current generative models only
focus on modeling either 2D bonding graphs or 3D geometries, which are two
complementary descriptors for molecules. The lack of ability to jointly model
both limits the improvement of generation quality and further downstream
applications. In this paper, we propose a new joint 2D and 3D diffusion model
(JODO) that generates complete molecules with atom types, formal charges, bond
information, and 3D coordinates. To capture the correlation between molecular
graphs and geometries in the diffusion process, we develop a Diffusion Graph
Transformer to parameterize the data prediction model that recovers the
original data from noisy data. The Diffusion Graph Transformer interacts node
and edge representations based on our relational attention mechanism, while
simultaneously propagating and updating scalar features and geometric vectors.
Our model can also be extended for inverse molecular design targeting single or
multiple quantum properties. In our comprehensive evaluation pipeline for
unconditional joint generation, the results of the experiment show that JODO
remarkably outperforms the baselines on the QM9 and GEOM-Drugs datasets.
Furthermore, our model excels in few-step fast sampling, as well as in inverse
molecule design and molecular graph generation. Our code is provided in
https://github.com/GRAPH-0/JODO
Realization of Bad Message Filtering System Based on kNN
Abstract: The transformation is implemented from short message to feature vector in this paper based on the ICTCLAS system. Then we use the kNN method to come to carry on the classified recognition to the message content, thus realizing to filter bad message effectually. The method has been testified effective in experiment
Realization of Bad Message Filtering System Based on kNN
Abstract: The transformation is implemented from short message to feature vector in this paper based on the ICTCLAS system. Then we use the kNN method to come to carry on the classified recognition to the message content, thus realizing to filter bad message effectually. The method has been testified effective in experiment
Towards Better Dynamic Graph Learning: New Architecture and Unified Library
We propose DyGFormer, a new Transformer-based architecture for dynamic graph
learning. DyGFormer is conceptually simple and only needs to learn from nodes'
historical first-hop interactions by: (1) a neighbor co-occurrence encoding
scheme that explores the correlations of the source node and destination node
based on their historical sequences; (2) a patching technique that divides each
sequence into multiple patches and feeds them to Transformer, allowing the
model to effectively and efficiently benefit from longer histories. We also
introduce DyGLib, a unified library with standard training pipelines,
extensible coding interfaces, and comprehensive evaluating protocols to promote
reproducible, scalable, and credible dynamic graph learning research. By
performing exhaustive experiments on thirteen datasets for dynamic link
prediction and dynamic node classification tasks, we find that DyGFormer
achieves state-of-the-art performance on most of the datasets, demonstrating
its effectiveness in capturing nodes' correlations and long-term temporal
dependencies. Moreover, some results of baselines are inconsistent with
previous reports, which may be caused by their diverse but less rigorous
implementations, showing the importance of DyGLib. All the used resources are
publicly available at https://github.com/yule-BUAA/DyGLib.Comment: Accepted at NeurIPS 202
Predicting Temporal Sets with Deep Neural Networks
Given a sequence of sets, where each set contains an arbitrary number of
elements, the problem of temporal sets prediction aims to predict the elements
in the subsequent set. In practice, temporal sets prediction is much more
complex than predictive modelling of temporal events and time series, and is
still an open problem. Many possible existing methods, if adapted for the
problem of temporal sets prediction, usually follow a two-step strategy by
first projecting temporal sets into latent representations and then learning a
predictive model with the latent representations. The two-step approach often
leads to information loss and unsatisfactory prediction performance. In this
paper, we propose an integrated solution based on the deep neural networks for
temporal sets prediction. A unique perspective of our approach is to learn
element relationship by constructing set-level co-occurrence graph and then
perform graph convolutions on the dynamic relationship graphs. Moreover, we
design an attention-based module to adaptively learn the temporal dependency of
elements and sets. Finally, we provide a gated updating mechanism to find the
hidden shared patterns in different sequences and fuse both static and dynamic
information to improve the prediction performance. Experiments on real-world
data sets demonstrate that our approach can achieve competitive performances
even with a portion of the training data and can outperform existing methods
with a significant margin.Comment: 9 pages, 6 figures, Proceedings of the 26th ACM SIGKDD Conference on
Knowledge Discovery and Data Mining (KDD '2020
A review of high‐velocity impact on fiber‐reinforced textile composites: potential for aero engine applications
Considerable research has indicated that fiber-reinforced textile composites are significantly beneficial to the aerospace industry, especially aero engines, due to their high specific strength, specific stiffness, corrosion resistance, and fatigue resistance. However, damage caused by high-velocity impacts is a critical limitation factor in a wide range of applications. This paper presents an overview of the development, material characterizations, and applications of fiber-reinforced textile composites for aero engines. These textile composites are classified into four categories including two-dimensional (2D) woven composites, 2D braided composites, 3D woven composites, and 3D braided composites. The complex damage mechanisms of these composite materials due to high-velocity impacts are discussed in detail as well
A two-step lineage reprogramming strategy to generate functionally competent human hepatocytes from fibroblasts
Terminally differentiated cells can be generated by lineage reprogramming, which is, however, hindered by incomplete conversion with residual initial cell identity and partial functionality. Here, we demonstrate a new reprogramming strategy by mimicking the natural regeneration route, which permits generating expandable hepatic progenitor cells and functionally competent human hepatocytes. Fibroblasts were first induced into human hepatic progenitor-like cells (hHPLCs), which could robustly expand in vitro and efficiently engraft in vivo. Moreover, hHPLCs could be efficiently induced into mature human hepatocytes (hiHeps) in vitro, whose molecular identity highly resembles primary human hepatocytes (PHHs). Most importantly, hiHeps could be generated in large quantity and were functionally competent to replace PHHs for drug-metabolism estimation, toxicity prediction and hepatitis B virus infection modeling. Our results highlight the advantages of the progenitor stage for successful lineage reprogramming. This strategy is promising for generating other mature human cell types by lineage reprogramming.</p
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