134 research outputs found
Can We `Feel' the Temperature of Knowledge? Modelling Scientific Popularity Dynamics via Thermodynamics
Just like everything in the nature, scientific topics flourish and perish.
While existing literature well captures article's life-cycle via citation
patterns, little is known about how scientific popularity and impact evolves
for a specific topic. It would be most intuitive if we could `feel' topic's
activity just as we perceive the weather by temperature. Here, we conceive
knowledge temperature to quantify topic overall popularity and impact through
citation network dynamics. Knowledge temperature includes 2 parts. One part
depicts lasting impact by assessing knowledge accumulation with an analogy
between topic evolution and isobaric expansion. The other part gauges temporal
changes in knowledge structure, an embodiment of short-term popularity, through
the rate of entropy change with internal energy, 2 thermodynamic variables
approximated via node degree and edge number. Our analysis of representative
topics with size ranging from 1000 to over 30000 articles reveals that the key
to flourishing is topics' ability in accumulating useful information for future
knowledge generation. Topics particularly experience temperature surges when
their knowledge structure is altered by influential articles. The spike is
especially obvious when there appears a single non-trivial novel research focus
or merging in topic structure. Overall, knowledge temperature manifests topics'
distinct evolutionary cycles
New insights into stress changes before and after the Wenchuan Earthquake using hydraulic fracturing measurements
AbstractThis paper summarizes in situ stress data by hydraulic fracturing method over the past 10years along the Longmenshan fault belt, and these data can be divided into three segments: northern, middle, and southern. The orientations of the maximum horizontal stress rotate from north-northwest in the northern to northwest in the middle, and to west-northwest in the southern. The stress magnitudes are characterized by higher values in the two ends and lower values in the middle segment. Furthermore, three stress measurement campaigns in two boreholes on the northern segment of the Longmenshan fault belt, before and after the great earthquake, show clear stress decrease of 23%–29% in the shallow crust after the earthquake. Analysis using the mathematical fitting method also indicates a decrease in regional stress state after the earthquake. Meanwhile, the frictional characteristic indexes based on the stress measurements further imply that the frictional strength of the Longmenshan fault belt is characterized by a strong southern segment, a weak middle segment, and a moderately strong northern segment. The analysis based on the stress data implies that the northern and southern segments of the fault belt are extremely important stress concentration and transformation nodes of the regional stress regime
Exploring and Verbalizing Academic Ideas by Concept Co-occurrence
Researchers usually come up with new ideas only after thoroughly
comprehending vast quantities of literature. The difficulty of this procedure
is exacerbated by the fact that the number of academic publications is growing
exponentially. In this study, we devise a framework based on concept
co-occurrence for academic idea inspiration, which has been integrated into a
research assistant system. From our perspective, the fusion of two concepts
that co-occur in an academic paper can be regarded as an important way of the
emergence of a new idea. We construct evolving concept graphs according to the
co-occurrence relationship of concepts from 20 disciplines or topics. Then we
design a temporal link prediction method based on masked language model to
explore potential connections between different concepts. To verbalize the
newly discovered connections, we also utilize the pretrained language model to
generate a description of an idea based on a new data structure called
co-occurrence citation quintuple. We evaluate our proposed system using both
automatic metrics and human assessment. The results demonstrate that our system
has broad prospects and can assist researchers in expediting the process of
discovering new ideas.Comment: Accepted by ACL 202
Graph Out-of-Distribution Generalization with Controllable Data Augmentation
Graph Neural Network (GNN) has demonstrated extraordinary performance in
classifying graph properties. However, due to the selection bias of training
and testing data (e.g., training on small graphs and testing on large graphs,
or training on dense graphs and testing on sparse graphs), distribution
deviation is widespread. More importantly, we often observe \emph{hybrid
structure distribution shift} of both scale and density, despite of one-sided
biased data partition. The spurious correlations over hybrid distribution
deviation degrade the performance of previous GNN methods and show large
instability among different datasets. To alleviate this problem, we propose
\texttt{OOD-GMixup} to jointly manipulate the training distribution with
\emph{controllable data augmentation} in metric space. Specifically, we first
extract the graph rationales to eliminate the spurious correlations due to
irrelevant information. Secondly, we generate virtual samples with perturbation
on graph rationale representation domain to obtain potential OOD training
samples. Finally, we propose OOD calibration to measure the distribution
deviation of virtual samples by leveraging Extreme Value Theory, and further
actively control the training distribution by emphasizing the impact of virtual
OOD samples. Extensive studies on several real-world datasets on graph
classification demonstrate the superiority of our proposed method over
state-of-the-art baselines.Comment: Under revie
Exploring the Limits of Historical Information for Temporal Knowledge Graph Extrapolation
Temporal knowledge graphs, representing the dynamic relationships and
interactions between entities over time, have been identified as a promising
approach for event forecasting. However, a limitation of most temporal
knowledge graph reasoning methods is their heavy reliance on the recurrence or
periodicity of events, which brings challenges to inferring future events
related to entities that lack historical interaction. In fact, the current
state of affairs is often the result of a combination of historical information
and underlying factors that are not directly observable. To this end, we
investigate the limits of historical information for temporal knowledge graph
extrapolation and propose a new event forecasting model called Contrastive
Event Network (CENET) based on a novel training framework of historical
contrastive learning. CENET learns both the historical and non-historical
dependency to distinguish the most potential entities that best match the given
query. Simultaneously, by launching contrastive learning, it trains
representations of queries to probe whether the current moment is more
dependent on historical or non-historical events. These representations further
help train a binary classifier, whose output is a boolean mask, indicating the
related entities in the search space. During the inference process, CENET
employs a mask-based strategy to generate the final results. We evaluate our
proposed model on five benchmark graphs. The results demonstrate that CENET
significantly outperforms all existing methods in most metrics, achieving at
least 8.3% relative improvement of Hits@1 over previous state-of-the-art
baselines on event-based datasets.Comment: Extended version of AAAI paper arXiv:2211.1090
Enhancing Uncertainty-Based Hallucination Detection with Stronger Focus
Large Language Models (LLMs) have gained significant popularity for their
impressive performance across diverse fields. However, LLMs are prone to
hallucinate untruthful or nonsensical outputs that fail to meet user
expectations in many real-world applications. Existing works for detecting
hallucinations in LLMs either rely on external knowledge for reference
retrieval or require sampling multiple responses from the LLM for consistency
verification, making these methods costly and inefficient. In this paper, we
propose a novel reference-free, uncertainty-based method for detecting
hallucinations in LLMs. Our approach imitates human focus in factuality
checking from three aspects: 1) focus on the most informative and important
keywords in the given text; 2) focus on the unreliable tokens in historical
context which may lead to a cascade of hallucinations; and 3) focus on the
token properties such as token type and token frequency. Experimental results
on relevant datasets demonstrate the effectiveness of our proposed method,
which achieves state-of-the-art performance across all the evaluation metrics
and eliminates the need for additional information.Comment: Accepted by EMNLP 2023 (main conference
Effects of Heterozygous Deletion of Autism-related gene Cullin-3 in mice
Autism Spectrum Disorder (ASD) is a developmental disorder in which children display repetitive behavior, restricted range of interests, and atypical social interaction and communication. CUL3, coding for a Cullin family scaffold protein mediating assembly of ubiquitin ligase complexes through BTB domain substrate-recruiting adaptors, has been identified as a high-risk gene for autism. Although complete knockout of Cul3 results in embryonic lethality, Cul3 heterozygous mice have reduced CUL3 protein, demonstrate comparable body weight, and display minimal behavioral differences including decreased spatial object recognition memory. In measures of reciprocal social interaction, Cul3 heterozygous mice behaved similarly to their wild-type littermates. In area CA1 of hippocampus, reduction of Cul3 significantly increased mEPSC frequency but not amplitude nor baseline evoked synaptic transmission or paired-pulse ratio. Sholl and spine analysis data suggest there is a small yet significant difference in CA1 pyramidal neuron dendritic branching and stubby spine density. Unbiased proteomic analysis of Cul3 heterozygous brain tissue revealed dysregulation of various cytoskeletal organization proteins, among others. Overall, our results suggest that Cul3 heterozygous deletion impairs spatial object recognition memory, alters cytoskeletal organization proteins, but does not cause major hippocampal neuronal morphology, functional, or behavioral abnormalities in adult global Cul3 heterozygous mice
ONCache: A Cache-Based Low-Overhead Container Overlay Network
Recent years have witnessed a widespread adoption of containers. While
containers simplify and accelerate application development, existing container
network technologies either incur significant overhead, which hurts performance
for distributed applications, or lose flexibility or compatibility, which
hinders the widespread deployment in production.
We design and implement ONCache (\textbf{O}verlay \textbf{N}etwork
\textbf{Cache}), a cache-based container overlay network, to eliminate the
overhead while keeping flexibility and compatibility. We carefully analyze the
difference between an overlay network and a host network, and find that an
overlay network incurs extra packet processing, including encapsulating,
intra-host routing, namespace traversing and packet filtering. Fortunately, the
extra processing exhibits an \emph{invariance property}, e.g., most packets of
the same flow have the same processing results. This property motivates us to
cache the extra processing results. With the proposed cache, ONCache
significantly reduces the extra overhead while maintaining the same flexibility
and compatibility as standard overlay networks. We implement ONCache using eBPF
with only 524 lines of code, and deploy ONCache as a plugin of Antrea.
With ONCache, container communication achieves similar performance as host
communication. Compared to the standard overlay network, ONCache improves the
throughput and request-response transaction rate by 12\% and 36\% for TCP (20\%
and 34\% for UDP), while significant reduces per-packet CPU overhead. Many
distributed applications also benefit from ONCache
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