392 research outputs found
RulE: Neural-Symbolic Knowledge Graph Reasoning with Rule Embedding
Knowledge graph (KG) reasoning is an important problem for knowledge graphs.
It predicts missing links by reasoning on existing facts. Knowledge graph
embedding (KGE) is one of the most popular methods to address this problem. It
embeds entities and relations into low-dimensional vectors and uses the learned
entity/relation embeddings to predict missing facts. However, KGE only uses
zeroth-order (propositional) logic to encode existing triplets (e.g., ``Alice
is Bob's wife."); it is unable to leverage first-order (predicate) logic to
represent generally applicable logical \textbf{rules} (e.g., ``''). On the other hand, traditional rule-based KG reasoning methods
usually rely on hard logical rule inference, making it brittle and hardly
competitive with KGE. In this paper, we propose RulE, a novel and principled
framework to represent and model logical rules and triplets. RulE jointly
represents entities, relations and logical rules in a unified embedding space.
By learning an embedding for each logical rule, RulE can perform logical rule
inference in a soft way and give a confidence score to each grounded rule,
similar to how KGE gives each triplet a confidence score. Compared to KGE
alone, RulE allows injecting prior logical rule information into the embedding
space, which improves the generalization of knowledge graph embedding. Besides,
the learned confidence scores of rules improve the logical rule inference
process by softly controlling the contribution of each rule, which alleviates
the brittleness of logic. We evaluate our method with link prediction tasks.
Experimental results on multiple benchmark KGs demonstrate the effectiveness of
RulE
Text-to-3D with Classifier Score Distillation
Text-to-3D generation has made remarkable progress recently, particularly
with methods based on Score Distillation Sampling (SDS) that leverages
pre-trained 2D diffusion models. While the usage of classifier-free guidance is
well acknowledged to be crucial for successful optimization, it is considered
an auxiliary trick rather than the most essential component. In this paper, we
re-evaluate the role of classifier-free guidance in score distillation and
discover a surprising finding: the guidance alone is enough for effective
text-to-3D generation tasks. We name this method Classifier Score Distillation
(CSD), which can be interpreted as using an implicit classification model for
generation. This new perspective reveals new insights for understanding
existing techniques. We validate the effectiveness of CSD across a variety of
text-to-3D tasks including shape generation, texture synthesis, and shape
editing, achieving results superior to those of state-of-the-art methods. Our
project page is https://xinyu-andy.github.io/Classifier-Score-DistillationComment: Our project page is
https://xinyu-andy.github.io/Classifier-Score-Distillatio
Large Language Models are In-Context Semantic Reasoners rather than Symbolic Reasoners
The emergent few-shot reasoning capabilities of Large Language Models (LLMs)
have excited the natural language and machine learning community over recent
years. Despite of numerous successful applications, the underlying mechanism of
such in-context capabilities still remains unclear. In this work, we
hypothesize that the learned \textit{semantics} of language tokens do the most
heavy lifting during the reasoning process. Different from human's symbolic
reasoning process, the semantic representations of LLMs could create strong
connections among tokens, thus composing a superficial logical chain. To test
our hypothesis, we decouple semantics from the language reasoning process and
evaluate three kinds of reasoning abilities, i.e., deduction, induction and
abduction. Our findings reveal that semantics play a vital role in LLMs'
in-context reasoning -- LLMs perform significantly better when semantics are
consistent with commonsense but struggle to solve symbolic or
counter-commonsense reasoning tasks by leveraging in-context new knowledge. The
surprising observations question whether modern LLMs have mastered the
inductive, deductive and abductive reasoning abilities as in human
intelligence, and motivate research on unveiling the magic existing within the
black-box LLMs. On the whole, our analysis provides a novel perspective on the
role of semantics in developing and evaluating language models' reasoning
abilities. Code is available at {\url{https://github.com/XiaojuanTang/ICSR}}
Localization of CO gas leakages through acoustic emission multi-sensor fusion based on wavelet-RBFN modeling
CO leakage from transmission pipelines in carbon capture and storage systems may seriously endanger the ecological environment and human health. Therefore, there is a pressing need of an accurate and reliable leak localization method for CO pipelines. In this study, a novel method based on the combination of a wavelet packet algorithm and a radial basis function network (RBFN) is proposed to realize the leak location. Multiple acoustic emission (AE) sensors are first deployed to collect leakage signals of CO pipelines. The characteristics of the leakage signals from the AE sensors under different pressures are then analyzed in both time and frequency domains. Further, leakage signals are decomposed into three layers using wavelet decomposition theory. Wavelet packet energy and maximum value, and time difference calculated by cross-correlation are selected as the input feature vectors of the RBFN. Experiments were carried out on a laboratory-scale test rig to verify the validity and correctness of the proposed method. Leakage signals at different positions under different pressures were obtained on the CO pipeline leakage test bench. Compared with the time difference of arrival method, the relative error obtained using the proposed method is less than 2%, which has certain engineering application prospects
Improved field emission performance of carbon nanotube by introducing copper metallic particles
To improve the field emission performance of carbon nanotubes (CNTs), a simple and low-cost method was adopted in this article. We introduced copper particles for decorating the CNTs so as to form copper particle-CNT composites. The composites were fabricated by electrophoretic deposition technique which produced copper metallic particles localized on the outer wall of CNTs and deposited them onto indium tin oxide (ITO) electrode. The results showed that the conductivity increased from 10-5 to 4 × 10-5 S while the turn-on field was reduced from 3.4 to 2.2 V/μm. Moreover, the field emission current tended to be undiminished after continuous emission for 24 h. The reasons were summarized that introducing copper metallic particles to decorate CNTs could increase the surface roughness of the CNTs which was beneficial to field emission, restrain field emission current from saturating when the applied electric field was above the critical field. In addition, it could also improve the electrical contact by increasing the contact area between CNT and ITO electrode that was beneficial to the electron transport and avoided instable electron emission caused by thermal injury of CNTs
Is synthetic data from generative models ready for image recognition?
Recent text-to-image generation models have shown promising results in
generating high-fidelity photo-realistic images. Though the results are
astonishing to human eyes, how applicable these generated images are for
recognition tasks remains under-explored. In this work, we extensively study
whether and how synthetic images generated from state-of-the-art text-to-image
generation models can be used for image recognition tasks, and focus on two
perspectives: synthetic data for improving classification models in data-scarce
settings (i.e. zero-shot and few-shot), and synthetic data for large-scale
model pre-training for transfer learning. We showcase the powerfulness and
shortcomings of synthetic data from existing generative models, and propose
strategies for better applying synthetic data for recognition tasks. Code:
https://github.com/CVMI-Lab/SyntheticData.Comment: ICLR 2023, spotligh
AdaptivePose++: A Powerful Single-Stage Network for Multi-Person Pose Regression
Multi-person pose estimation generally follows top-down and bottom-up
paradigms. Both of them use an extra stage ( human
detection in top-down paradigm or grouping process in bottom-up paradigm) to
build the relationship between the human instance and corresponding keypoints,
thus leading to the high computation cost and redundant two-stage pipeline. To
address the above issue, we propose to represent the human parts as adaptive
points and introduce a fine-grained body representation method. The novel body
representation is able to sufficiently encode the diverse pose information and
effectively model the relationship between the human instance and corresponding
keypoints in a single-forward pass. With the proposed body representation, we
further deliver a compact single-stage multi-person pose regression network,
termed as AdaptivePose. During inference, our proposed network only needs a
single-step decode operation to form the multi-person pose without complex
post-processes and refinements. We employ AdaptivePose for both 2D/3D
multi-person pose estimation tasks to verify the effectiveness of AdaptivePose.
Without any bells and whistles, we achieve the most competitive performance on
MS COCO and CrowdPose in terms of accuracy and speed. Furthermore, the
outstanding performance on MuCo-3DHP and MuPoTS-3D further demonstrates the
effectiveness and generalizability on 3D scenes. Code is available at
https://github.com/buptxyb666/AdaptivePose.Comment: Submit to IEEE TCSVT; 11 pages. arXiv admin note: text overlap with
arXiv:2112.1363
Metal‐Organic Framework Thin Films as Ideal Matrices for Azide Photolysis in Vacuum
Studies on reactions in solutions are often hampered by solvent effects. In addition, detailed investigation on kinetics is limited to the small temperature regime where the solvent is liquid. Here, we report the in situ spectroscopic observation of UV-induced photochemical reactions of aryl azides within a crystalline matrix in vacuum. The matrices are formed by attaching the reactive moieties to ditopic linkers, which are then assembled to yield metal–organic frameworks (MOFs) and surface-mounted MOFs (SURMOFs). These porous, crystalline frameworks are then used as model systems to study azide-related chemical processes under ultrahigh vacuum (UHV) conditions, where solvent effects can be safely excluded and in a large temperature regime. Infrared reflection absorption spectroscopy (IRRAS) allowed us to monitor the photoreaction of azide in SURMOFs precisely. The in situ IRRAS data, in conjunction with XRD, MS, and XPS, reveal that illumination with UV light first leads to forming a nitrene intermediate. In the second step, an intramolecular rearrangement occurs, yielding an indoloindole derivative. These findings unveil a novel pathway for precisely studying azide-related chemical transformations. Reference experiments carried out for solvent-loaded SURMOFs reveal a huge diversity of other reaction schemes, thus highlighting the need for model systems studied under UHV conditions
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