118 research outputs found
A Sigmoid-based car-following model to improve acceleration stability in traffic oscillation and following failure in free flow
This paper proposes an improved Intelligent driving model (Sigmoid-IDM) to
address the problems of excessive acceleration in traffic oscillation and
following failure in free flow. The Sigmoid-IDM uses a Sigmoid function to
enhance the start-following characteristics, improve the output strategy of the
spacing term, and stabilize the steady-state velocity in free flow. Moreover,
the model asymmetry is improved by means of introducing cautious following
distance, driving caution factor, and segmentation function. The
anti-interference ability of the Sigmoid-IDM is demonstrated by local stability
and string stability analyses.Comment: 15 pages, 51 figures
A Safety Control Method of Car-Following Trajectory Planning Based on LSTM
This paper focuses on the potential safety hazards of collision in car-following behaviour generated by deep learning models. Based on an intelligent LSTM model, combined with a Gipps model of safe collision avoidance, a new, Gipps-LSTM model is constructed, which can not only learn the intelligent behaviour of people but also ensure the safety of vehicles. The idea of the Gipps-LSTM model combination is as follows: the concept of a potential collision point (PCP) is introduced, and the LSTM model or Gipps model is controlled and started through a risk judgment algorithm. Dataset 1 and dataset 2 are used to train and simulate the LSTM model and Gipps-LSTM model. The simulation results show that the Gipps-LSTM can solve the problem of partial trajectory collision in the LSTM model simulation. Moreover, the risk level of all trajectories is lower than that of the LSTM model. The safety and stability of the model are verified by multi-vehicle loop simulation and multi-vehicle linear simulation. Compared with the LSTM model, the safety of the Gipps-LSTM model is improved by 42.02%, and the convergence time is reduced by 25 seconds
Modeling Fine-grained Information via Knowledge-aware Hierarchical Graph for Zero-shot Entity Retrieval
Zero-shot entity retrieval, aiming to link mentions to candidate entities
under the zero-shot setting, is vital for many tasks in Natural Language
Processing. Most existing methods represent mentions/entities via the sentence
embeddings of corresponding context from the Pre-trained Language Model.
However, we argue that such coarse-grained sentence embeddings can not fully
model the mentions/entities, especially when the attention scores towards
mentions/entities are relatively low. In this work, we propose GER, a
\textbf{G}raph enhanced \textbf{E}ntity \textbf{R}etrieval framework, to
capture more fine-grained information as complementary to sentence embeddings.
We extract the knowledge units from the corresponding context and then
construct a mention/entity centralized graph. Hence, we can learn the
fine-grained information about mention/entity by aggregating information from
these knowledge units. To avoid the graph information bottleneck for the
central mention/entity node, we construct a hierarchical graph and design a
novel Hierarchical Graph Attention Network~(HGAN). Experimental results on
popular benchmarks demonstrate that our proposed GER framework performs better
than previous state-of-the-art models. The code has been available at
https://github.com/wutaiqiang/GER-WSDM2023.Comment: 9 pages, 5 figure
Edge-free but Structure-aware: Prototype-Guided Knowledge Distillation from GNNs to MLPs
Distilling high-accuracy Graph Neural Networks~(GNNs) to low-latency
multilayer perceptrons~(MLPs) on graph tasks has become a hot research topic.
However, MLPs rely exclusively on the node features and fail to capture the
graph structural information. Previous methods address this issue by processing
graph edges into extra inputs for MLPs, but such graph structures may be
unavailable for various scenarios. To this end, we propose a Prototype-Guided
Knowledge Distillation~(PGKD) method, which does not require graph
edges~(edge-free) yet learns structure-aware MLPs. Specifically, we analyze the
graph structural information in GNN teachers, and distill such information from
GNNs to MLPs via prototypes in an edge-free setting. Experimental results on
popular graph benchmarks demonstrate the effectiveness and robustness of the
proposed PGKD.Comment: 8 pages, 4 figures, 9 table
ConRF: Zero-shot Stylization of 3D Scenes with Conditioned Radiation Fields
Most of the existing works on arbitrary 3D NeRF style transfer required
retraining on each single style condition. This work aims to achieve zero-shot
controlled stylization in 3D scenes utilizing text or visual input as
conditioning factors. We introduce ConRF, a novel method of zero-shot
stylization. Specifically, due to the ambiguity of CLIP features, we employ a
conversion process that maps the CLIP feature space to the style space of a
pre-trained VGG network and then refine the CLIP multi-modal knowledge into a
style transfer neural radiation field. Additionally, we use a 3D volumetric
representation to perform local style transfer. By combining these operations,
ConRF offers the capability to utilize either text or images as references,
resulting in the generation of sequences with novel views enhanced by global or
local stylization. Our experiment demonstrates that ConRF outperforms other
existing methods for 3D scene and single-text stylization in terms of visual
quality
MoleculeQA: A Dataset to Evaluate Factual Accuracy in Molecular Comprehension
Large language models are playing an increasingly significant role in
molecular research, yet existing models often generate erroneous information,
posing challenges to accurate molecular comprehension. Traditional evaluation
metrics for generated content fail to assess a model's accuracy in molecular
understanding. To rectify the absence of factual evaluation, we present
MoleculeQA, a novel question answering (QA) dataset which possesses 62K QA
pairs over 23K molecules. Each QA pair, composed of a manual question, a
positive option and three negative options, has consistent semantics with a
molecular description from authoritative molecular corpus. MoleculeQA is not
only the first benchmark for molecular factual bias evaluation but also the
largest QA dataset for molecular research. A comprehensive evaluation on
MoleculeQA for existing molecular LLMs exposes their deficiencies in specific
areas and pinpoints several particularly crucial factors for molecular
understanding.Comment: 19 pages, 8 figure
A Safety Control Method of Car-Following Trajectory Planning Based on LSTM
This paper focuses on the potential safety hazards of collision in car-following behaviour generated by deep learning models. Based on an intelligent LSTM model, combined with a Gipps model of safe collision avoidance, a new, Gipps-LSTM model is constructed, which can not only learn the intelligent behaviour of people but also ensure the safety of vehicles. The idea of the Gipps-LSTM model combination is as follows: the concept of a potential collision point (PCP) is introduced, and the LSTM model or Gipps model is controlled and started through a risk judgment algorithm. Dataset 1 and dataset 2 are used to train and simulate the LSTM model and Gipps-LSTM model. The simulation results show that the Gipps-LSTM can solve the problem of partial trajectory collision in the LSTM model simulation. Moreover, the risk level of all trajectories is lower than that of the LSTM model. The safety and stability of the model are verified by multi-vehicle loop simulation and multi-vehicle linear simulation. Compared with the LSTM model, the safety of the Gipps-LSTM model is improved by 42.02%, and the convergence time is reduced by 25 seconds
CTNeRF: Cross-time Transformer for dynamic neural radiance field from monocular video
The goal of our work is to generate high-quality novel views from monocular videos of complex and dynamic scenes. Prior methods, such as DynamicNeRF, have shown impressive performance by leveraging time-varying dynamic radiation fields. However, these methods have limitations when it comes to accurately modeling the motion of complex objects, which can lead to inaccurate and blurry renderings of details. To address this limitation, we propose a novel approach that builds upon a recent generalization NeRF, which aggregates nearby views onto new viewpoints. However, such methods are typically only effective for static scenes. To overcome this challenge, we introduce a module that operates in both the time and frequency domains to aggregate the features of object motion. This allows us to learn the relationship between frames and generate higher-quality images. Our experiments demonstrate significant improvements over state-of-the-art methods on dynamic scene datasets. Specifically, our approach outperforms existing methods in terms of both the accuracy and visual quality of the synthesized views. Our code is available on https://github.com/xingy038/CTNeRF
Oxygen Vacancy-Enriched Amorphous Transition Metal Ternary Oxides toward Highly Efficient Oxygen Evolution Reaction
Developing highly efficient oxygen evolution reaction (OER) electrocatalysts based on earth-abundant elements is critical to improve the efficiency of water electrolysis, but it remains a challenge. Herein, an amorphous ternary oxides composites FeNiCoOx/CoOx with rich oxygen vacancies are developed through a low-cost wet chemical deposition strategy toward this challenge. Benefiting from the synergistic effect of multimetal atom interaction and high exposure of active sites caused by oxygen vacancies and amorphous structure, the as-developed FeNiCoOx/CoOx electrocatalyst exhibits an exceptional catalytic performance with a low overpotential of only 221 mV at a current density of 100 mA cm-2 and negligible performance degradation over 240 h. Furthermore, the FeNiCoOx/CoOx-assembled anion exchange membrane water electrolyzer (AEMWE) can achieve a high current density of 1 A cm-2 at a low voltage of 1.765 V, demonstrating its great potential for practical application
Ultrahigh Thermoelectric Performance by Electron and Phonon Critical Scattering in Cu 2 Se 1‐x I x
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102251/1/adma201302660.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102251/2/adma201302660-sup-0001-S1.pd
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