475 research outputs found
药研云医生——基于深度学习的药物疗效预测系统
The drug efficacy prediction system can link the pharmacological big data with the disease target protein through in-depth learning and other methods, and then build an artificial intelligence model of drugs and diseases, explore the originally seemingly “irrelevant” diseases and syndromes and the potential efficacy of drugs, and greatly reduce the drug development cost and time limit through drug reuse
YOLO-Drone:Airborne real-time detection of dense small objects from high-altitude perspective
Unmanned Aerial Vehicles (UAVs), specifically drones equipped with remote
sensing object detection technology, have rapidly gained a broad spectrum of
applications and emerged as one of the primary research focuses in the field of
computer vision. Although UAV remote sensing systems have the ability to detect
various objects, small-scale objects can be challenging to detect reliably due
to factors such as object size, image degradation, and real-time limitations.
To tackle these issues, a real-time object detection algorithm (YOLO-Drone) is
proposed and applied to two new UAV platforms as well as a specific light
source (silicon-based golden LED). YOLO-Drone presents several novelties: 1)
including a new backbone Darknet59; 2) a new complex feature aggregation module
MSPP-FPN that incorporated one spatial pyramid pooling and three atrous spatial
pyramid pooling modules; 3) and the use of Generalized Intersection over Union
(GIoU) as the loss function. To evaluate performance, two benchmark datasets,
UAVDT and VisDrone, along with one homemade dataset acquired at night under
silicon-based golden LEDs, are utilized. The experimental results show that, in
both UAVDT and VisDrone, the proposed YOLO-Drone outperforms state-of-the-art
(SOTA) object detection methods by improving the mAP of 10.13% and 8.59%,
respectively. With regards to UAVDT, the YOLO-Drone exhibits both high
real-time inference speed of 53 FPS and a maximum mAP of 34.04%. Notably,
YOLO-Drone achieves high performance under the silicon-based golden LEDs, with
a mAP of up to 87.71%, surpassing the performance of YOLO series under ordinary
light sources. To conclude, the proposed YOLO-Drone is a highly effective
solution for object detection in UAV applications, particularly for night
detection tasks where silicon-based golden light LED technology exhibits
significant superiority
Boundary-Aware Proposal Generation Method for Temporal Action Localization
The goal of Temporal Action Localization (TAL) is to find the categories and
temporal boundaries of actions in an untrimmed video. Most TAL methods rely
heavily on action recognition models that are sensitive to action labels rather
than temporal boundaries. More importantly, few works consider the background
frames that are similar to action frames in pixels but dissimilar in semantics,
which also leads to inaccurate temporal boundaries. To address the challenge
above, we propose a Boundary-Aware Proposal Generation (BAPG) method with
contrastive learning. Specifically, we define the above background frames as
hard negative samples. Contrastive learning with hard negative mining is
introduced to improve the discrimination of BAPG. BAPG is independent of the
existing TAL network architecture, so it can be applied plug-and-play to
mainstream TAL models. Extensive experimental results on THUMOS14 and
ActivityNet-1.3 demonstrate that BAPG can significantly improve the performance
of TAL
FedDef: Defense Against Gradient Leakage in Federated Learning-based Network Intrusion Detection Systems
Deep learning (DL) methods have been widely applied to anomaly-based network
intrusion detection system (NIDS) to detect malicious traffic. To expand the
usage scenarios of DL-based methods, the federated learning (FL) framework
allows multiple users to train a global model on the basis of respecting
individual data privacy. However, it has not yet been systematically evaluated
how robust FL-based NIDSs are against existing privacy attacks under existing
defenses. To address this issue, we propose two privacy evaluation metrics
designed for FL-based NIDSs, including (1) privacy score that evaluates the
similarity between the original and recovered traffic features using
reconstruction attacks, and (2) evasion rate against NIDSs using Generative
Adversarial Network-based adversarial attack with the reconstructed benign
traffic. We conduct experiments to show that existing defenses provide little
protection that the corresponding adversarial traffic can even evade the SOTA
NIDS Kitsune. To defend against such attacks and build a more robust FL-based
NIDS, we further propose FedDef, a novel optimization-based input perturbation
defense strategy with theoretical guarantee. It achieves both high utility by
minimizing the gradient distance and strong privacy protection by maximizing
the input distance. We experimentally evaluate four existing defenses on four
datasets and show that our defense outperforms all the baselines in terms of
privacy protection with up to 7 times higher privacy score, while maintaining
model accuracy loss within 3% under optimal parameter combination.Comment: 14 pages, 9 figures, submitted to TIF
VILA: Learning Image Aesthetics from User Comments with Vision-Language Pretraining
Assessing the aesthetics of an image is challenging, as it is influenced by
multiple factors including composition, color, style, and high-level semantics.
Existing image aesthetic assessment (IAA) methods primarily rely on
human-labeled rating scores, which oversimplify the visual aesthetic
information that humans perceive. Conversely, user comments offer more
comprehensive information and are a more natural way to express human opinions
and preferences regarding image aesthetics. In light of this, we propose
learning image aesthetics from user comments, and exploring vision-language
pretraining methods to learn multimodal aesthetic representations.
Specifically, we pretrain an image-text encoder-decoder model with
image-comment pairs, using contrastive and generative objectives to learn rich
and generic aesthetic semantics without human labels. To efficiently adapt the
pretrained model for downstream IAA tasks, we further propose a lightweight
rank-based adapter that employs text as an anchor to learn the aesthetic
ranking concept. Our results show that our pretrained aesthetic vision-language
model outperforms prior works on image aesthetic captioning over the
AVA-Captions dataset, and it has powerful zero-shot capability for aesthetic
tasks such as zero-shot style classification and zero-shot IAA, surpassing many
supervised baselines. With only minimal finetuning parameters using the
proposed adapter module, our model achieves state-of-the-art IAA performance
over the AVA dataset.Comment: CVPR 2023,
https://github.com/google-research/google-research/tree/master/vil
A method review of the climate change impact on crop yield
Climate change significantly impacts global agricultural production, giving rise to considerable uncertainties. To explore these climate impacts, three independent methods have been employed: manipulated experiments, process-based crop models, and empirical statistical models. However, the uncertainty stemming from the use of different methods has received insufficient attention, and its implications remain unclear, necessitating a systematic review. In this study, we conducted a comprehensive review of numerous previous studies to summarize the historic development and current status of each method. Through a method comparison, we identified their respective strengths, limitations, and ideal areas of application. Additionally, we outlined potential prospects and suggested directions for future improvements, including clarifying the response mechanisms, updating simulation technologies, and developing multi-method ensembles. By addressing the knowledge gap regarding method differences, this review could contribute to a more accurate assessment of climate impacts on agriculture
Global Three-Dimensional Radiation Magnetohydrodynamic Simulations of Accretion onto a Stellar Mass Black Hole at Sub- and Near-critical Accretion Rates
We present global 3D radiation magnetohydrodynamical simulations of accretion
onto a 6.62 solar mass black hole with quasi-steady state accretion rates
reaching 0.016 to 0.9 times the critical accretion rate, which is defined as
the accretion rate to power the Eddington luminosity assuming a 10% radiative
efficiency, in different runs. The simulations show no sign of thermal
instability over hundreds of thermal timescales at 10 . The energy
dissipation happens close to the mid-plane in the near-critical runs and near
the disk surface in the low accretion rate run. The total radiative luminosity
inside 20 is about 1% to 30% the Eddington limit, with a
radiative efficiency of about 6% and 3%, respectively, in the sub- and
near-critical accretion regimes. In both cases, self-consistent turbulence
generated by the magnetorotational instability (MRI) leads to angular momentum
transfer, and the disk is supported by magnetic pressure. Outflows from the
central low-density funnel with a terminal velocity of 0.1 are seen
only in the near-critical runs. We conclude that these magnetic pressure
dominated disks are thermally stable and thicker than the disk, and
the effective temperature profiles are much flatter than that in the
disks. The magnetic pressure of these disks are comparable within an order of
magnitude with the previous analytical magnetic pressure dominated disk model.Comment: 17 pages, 13 figures, 3 tables, accepted for publication in Ap
Plasma kinetics: Discrete Boltzmann modelling and Richtmyer-Meshkov instability
A discrete Boltzmann model (DBM) for plasma kinetics is proposed. The
constructing of DBM mainly considers two aspects. The first is to build a
physical model with sufficient physical functions before simulation. The second
is to present schemes for extracting more valuable information from massive
data after simulation. For the first aspect, the model is equivalent to a
magnetohydrodynamic model plus a coarse-grained model for the most relevant TNE
behaviors including the entropy production rate. A number of typical benchmark
problems including Orszag-Tang (OT) vortex problem are used to verify the
physical functions of DBM. For the second aspect, the DBM use non-conserved
kinetic moments of (f-feq) to describe non-equilibrium state and behaviours of
complex system. The OT vortex problem and the Richtmyer-Meshkov instability
(RMI) are practical applications of the second aspect. For RMI with interface
inverse and re-shock process, it is found that, in the case without magnetic
field, the non-organized momentum flux shows the most pronounced effects near
shock front, while the non-organized energy flux shows the most pronounced
behaviors near perturbed interface. The influence of magnetic field on TNE
effects shows stages: before the interface inverse, the TNE strength is
enhanced by reducing the interface inverse speed; while after the interface
inverse, the TNE strength is significantly reduced. Both the global average TNE
strength and entropy production rate contributed by non-organized energy flux
can be used as physical criteria to identify whether or not the magnetic field
is sufficient to prevent the interface inverse.Comment: 20 pages, 15 figure
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