53 research outputs found
Structural Information Guided Multimodal Pre-training for Vehicle-centric Perception
Understanding vehicles in images is important for various applications such
as intelligent transportation and self-driving system. Existing vehicle-centric
works typically pre-train models on large-scale classification datasets and
then fine-tune them for specific downstream tasks. However, they neglect the
specific characteristics of vehicle perception in different tasks and might
thus lead to sub-optimal performance. To address this issue, we propose a novel
vehicle-centric pre-training framework called VehicleMAE, which incorporates
the structural information including the spatial structure from vehicle profile
information and the semantic structure from informative high-level natural
language descriptions for effective masked vehicle appearance reconstruction.
To be specific, we explicitly extract the sketch lines of vehicles as a form of
the spatial structure to guide vehicle reconstruction. The more comprehensive
knowledge distilled from the CLIP big model based on the similarity between the
paired/unpaired vehicle image-text sample is further taken into consideration
to help achieve a better understanding of vehicles. A large-scale dataset is
built to pre-train our model, termed Autobot1M, which contains about 1M vehicle
images and 12693 text information. Extensive experiments on four vehicle-based
downstream tasks fully validated the effectiveness of our VehicleMAE. The
source code and pre-trained models will be released at
https://github.com/Event-AHU/VehicleMAE.Comment: Accepted by AAAI-202
BClean: A Bayesian Data Cleaning System
There is a considerable body of work on data cleaning which employs various
principles to rectify erroneous data and transform a dirty dataset into a
cleaner one. One of prevalent approaches is probabilistic methods, including
Bayesian methods. However, existing probabilistic methods often assume a
simplistic distribution (e.g., Gaussian distribution), which is frequently
underfitted in practice, or they necessitate experts to provide a complex prior
distribution (e.g., via a programming language). This requirement is both
labor-intensive and costly, rendering these methods less suitable for
real-world applications. In this paper, we propose BClean, a Bayesian Cleaning
system that features automatic Bayesian network construction and user
interaction. We recast the data cleaning problem as a Bayesian inference that
fully exploits the relationships between attributes in the observed dataset and
any prior information provided by users. To this end, we present an automatic
Bayesian network construction method that extends a structure learning-based
functional dependency discovery method with similarity functions to capture the
relationships between attributes. Furthermore, our system allows users to
modify the generated Bayesian network in order to specify prior information or
correct inaccuracies identified by the automatic generation process. We also
design an effective scoring model (called the compensative scoring model)
necessary for the Bayesian inference. To enhance the efficiency of data
cleaning, we propose several approximation strategies for the Bayesian
inference, including graph partitioning, domain pruning, and pre-detection. By
evaluating on both real-world and synthetic datasets, we demonstrate that
BClean is capable of achieving an F-measure of up to 0.9 in data cleaning,
outperforming existing Bayesian methods by 2% and other data cleaning methods
by 15%.Comment: Our source code is available at https://github.com/yyssl88/BClea
Mechanism of rainfall-induced shallow landslide and stability prediction model
The rainfall-induced shallow landslides are primarily debris landslides, which features simultaneity with significant hazard, and the hydrological response mechanism of water table and soil moisture content to precipitation of this type of landslide is sophisticated, which makes it difficult to predict the slope stability accurately. To further study the influence of the rainfall-triggered internal hydrological responses on slope-stability, on-site precipitation infiltration monitoring, correlation analysis and mechanical analysis were carried out on the Houshanli landslide in Qingchuan County, Sichuan Province. The relationship between precipitation and water table was proposed based on climate and hydrological monitoring data obtained within three year interval. The response of rainfall infiltration, soil volumetric water content and water table were analyzed. The results indicate that: (1) groundwater exhibits periodic fluctuations throughout the year, characterized by three phases of slow decline, rapid decline, and rapid ascent; a linear negative correlation between precipitation and water table was found, and no significant correlation was observed with the water table increment; (2) through the infinite slope model and the relationship between precipitation and water table, a prediction model for shallow landslide stability was constructed. The precipitation threshold (81.8 mm/d) and water table threshold (0.73 m) were determined which has good agreement with the actual situations. This provides an early warning method for rainfall-induced shallow landslides by monitoring these two factors
Atlas of Transcription Factor Binding Sites from ENCODE DNase Hypersensitivity Data across 27 Tissue Types.
Characterizing the tissue-specific binding sites of transcription factors (TFs) is essential to reconstruct gene regulatory networks and predict functions for non-coding genetic variation. DNase-seq footprinting enables the prediction of genome-wide binding sites for hundreds of TFs simultaneously. Despite the public availability of high-quality DNase-seq data from hundreds of samples, a comprehensive, up-to-date resource for the locations of genomic footprints is lacking. Here, we develop a scalable footprinting workflow using two state-of-the-art algorithms: Wellington and HINT. We apply our workflow to detect footprints in 192 ENCODE DNase-seq experiments and predict the genomic occupancy of 1,515 human TFs in 27 human tissues. We validate that these footprints overlap true-positive TF binding sites from ChIP-seq. We demonstrate that the locations, depth, and tissue specificity of footprints predict effects of genetic variants on gene expression and capture a substantial proportion of genetic risk for complex traits
One-pot aqueous synthesis of cysteine-capped CdTe/CdS core-shell nanowires
Highly fluorescent cysteine-capped CdTe/CdS core-shell nanowires were successfully synthesized by reacting CdCl2 with NaHTe in aqueous solution under refluxing at 100 °C for 140 min. On increasing the reaction time from 10 to 140 min, CdTe/CdS nanocrystals gradually grew into nanorods and eventually completely evolved into nanowires. The nanowires have amino and carboxyl functional groups on their surfaces and can be well dispersed in aqueous solution. The as-prepared CdTe/CdS nanowires show a fluorescence quantum yield (QY) of 7.25 % due to the unique nature of cysteine and the formation of a CdS shell on the surface of the CdTe core, they have a narrower diameter distribution (d = ~5 nm) and a length in the range of 175-275 nm, and their aspect ratio is between 1/35 and 1/55
Fluid Field Modulation in Mass Transfer for Efficient Photocatalysis
Mass transfer is an essential factor determining photocatalytic performance, which can be modulated by fluid field via manipulating the kinetic characteristics of photocatalysts and photocatalytic intermediates. Past decades have witnessed the efforts and achievements made in manipulating mass transfer based on photocatalyst structure and composition design, and thus, a critical survey that scrutinizes the recent progress in this topic is urgently necessitated. This review examines the basic principles of how mass transfer behavior impacts photocatalytic activity accompanying with the discussion on theoretical simulation calculation including fluid flow speed and pattern. Meanwhile, newly emerged viable photocatalytic micro/nanomotors with self-thermophoresis, self-diffusiophoresis, and bubble-propulsion mechanisms as well as magnet-actuated photocatalytic artificial cilia for facilitating mass transfer will be covered. Furthermore, their applications in photocatalytic hydrogen evolution, carbon dioxide reduction, organic pollution degradation, bacteria disinfection and so forth are scrutinized. Finally, a brief summary and future outlook are presented, providing a viable guideline to those working in photocatalysis, mass transfer, and other related fields
Structural Information Guided Multimodal Pre-training for Vehicle-Centric Perception
Understanding vehicles in images is important for various applications such as intelligent transportation and self-driving system. Existing vehicle-centric works typically pre-train models on large-scale classification datasets and then fine-tune them for specific downstream tasks. However, they neglect the specific characteristics of vehicle perception in different tasks and might thus lead to sub-optimal performance. To address this issue, we propose a novel vehicle-centric pre-training framework called VehicleMAE, which incorporates the structural information including the spatial structure from vehicle profile information and the semantic structure from informative high-level natural language descriptions for effective masked vehicle appearance reconstruction. To be specific, we explicitly extract the sketch lines of vehicles as a form of the spatial structure to guide vehicle reconstruction. The more comprehensive knowledge distilled from the CLIP big model based on the similarity between the paired/unpaired vehicle image-text sample is further taken into consideration to help achieve a better understanding of vehicles. A large-scale dataset is built to pre-train our model, termed Autobot1M, which contains about 1M vehicle images and 12693 text information. Extensive experiments on four vehicle-based downstream tasks fully validated the effectiveness of our VehicleMAE. The source code and pre-trained models will be released at https://github.com/Event-AHU/VehicleMAE
Interfacial ice sprouting during salty water droplet freezing
Abstract Icing of seawater droplets is capable of causing catastrophic damage to vessels, buildings, and human life, yet it also holds great potential for enhancing applications such as droplet-based freeze desalination and anti-icing of sea sprays. While large-scale sea ice growth has been investigated for decades, the icing features of small salty droplets remain poorly understood. Here, we demonstrate that salty droplet icing is governed by salt rejection-accompanied ice crystal growth, resulting in freezing dynamics different from pure water. Aided by the observation of brine films emerging on top of frozen salty droplets, we propose a universal definition of freezing duration to quantify the icing rate of droplets having varying salt concentrations. Furthermore, we show that the morphology of frozen salty droplets is governed by ice crystals that sprout from the bottom of the brine film. These crystals grow until they pierce the free interface, which we term ice sprouting. We reveal that ice sprouting is controlled by condensation at the brine film free interface, a mechanism validated through molecular dynamics simulations. Our findings shed light on the distinct physics that govern salty droplet icing, knowledge that is essential for the development of related technologies
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