147 research outputs found
Graph-Level Embedding for Time-Evolving Graphs
Graph representation learning (also known as network embedding) has been
extensively researched with varying levels of granularity, ranging from nodes
to graphs. While most prior work in this area focuses on node-level
representation, limited research has been conducted on graph-level embedding,
particularly for dynamic or temporal networks. However, learning
low-dimensional graph-level representations for dynamic networks is critical
for various downstream graph retrieval tasks such as temporal graph similarity
ranking, temporal graph isomorphism, and anomaly detection. In this paper, we
present a novel method for temporal graph-level embedding that addresses this
gap. Our approach involves constructing a multilayer graph and using a modified
random walk with temporal backtracking to generate temporal contexts for the
graph's nodes. We then train a "document-level" language model on these
contexts to generate graph-level embeddings. We evaluate our proposed model on
five publicly available datasets for the task of temporal graph similarity
ranking, and our model outperforms baseline methods. Our experimental results
demonstrate the effectiveness of our method in generating graph-level
embeddings for dynamic networks.Comment: In Companion Proceedings of the ACM Web Conference 202
Reduced-order modeling of a sliding ring on an elastic rod with incremental potential formulation
Mechanical interactions between rigid rings and flexible cables are
widespread in both daily life (hanging clothes) and engineering system (closing
a tether net). A reduced-order method for the dynamic analysis of sliding rings
on a deformable one-dimensional (1D) rod-like object is proposed. In contrast
to discretize the joint rings into multiple nodes and edges for contact
detection and numerical simulation, a single point is used to reduce the order
of the numerical model. In order to achieve the non-deviation condition between
sliding ring and flexible rod, a novel barrier functional is derived based on
incremental potential theory, and the tangent frictional interplay is later
procured by a lagged dissipative formulation. The proposed barrier functional
and the associated frictional functional are continuous, hence the
nonlinear elastodynamic system can be solved variationally by an implicit
time-stepping scheme. The numerical framework is first applied to simple
examples where the analytical solutions are available for validation. Then,
multiple complex practical engineering examples are considered to showcase the
effectiveness of the proposed method. The simplified ring-to-rod interaction
model can provide lifelike visual effect for picture animations, and also can
support the optimal design for space debris removal system.Comment: 15 pages, 9 figure
Embedding Heterogeneous Networks into Hyperbolic Space Without Meta-path
Networks found in the real-world are numerous and varied. A common type of
network is the heterogeneous network, where the nodes (and edges) can be of
different types. Accordingly, there have been efforts at learning
representations of these heterogeneous networks in low-dimensional space.
However, most of the existing heterogeneous network embedding methods suffer
from the following two drawbacks: (1) The target space is usually Euclidean.
Conversely, many recent works have shown that complex networks may have
hyperbolic latent anatomy, which is non-Euclidean. (2) These methods usually
rely on meta-paths, which require domain-specific prior knowledge for meta-path
selection. Additionally, different down-streaming tasks on the same network
might require different meta-paths in order to generate task-specific
embeddings. In this paper, we propose a novel self-guided random walk method
that does not require meta-path for embedding heterogeneous networks into
hyperbolic space. We conduct thorough experiments for the tasks of network
reconstruction and link prediction on two public datasets, showing that our
model outperforms a variety of well-known baselines across all tasks.Comment: In proceedings of the 35th AAAI Conference on Artificial Intelligenc
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