539 research outputs found
Attack and Defense Analysis of Learned Image Compression
Learned image compression (LIC) is becoming more and more popular these years
with its high efficiency and outstanding compression quality. Still, the
practicality against modified inputs added with specific noise could not be
ignored. White-box attacks such as FGSM and PGD use only gradient to compute
adversarial images that mislead LIC models to output unexpected results. Our
experiments compare the effects of different dimensions such as attack methods,
models, qualities, and targets, concluding that in the worst case, there is a
61.55% decrease in PSNR or a 19.15 times increase in bpp under the PGD attack.
To improve their robustness, we conduct adversarial training by adding
adversarial images into the training datasets, which obtains a 95.52% decrease
in the R-D cost of the most vulnerable LIC model. We further test the
robustness of H.266, whose better performance on reconstruction quality extends
its possibility to defend one-step or iterative adversarial attacks
Experimental study on seismic performance of prestressed concrete solid square piles
Prestressed concrete solid square (PCSS) piles exhibit superior lateral bearing capacity and durability compared to pretensioned spun concrete pipe piles, and are more suitable for pile foundation engineering in high-intensity seismic regions and corrosive environments. There is still a lack of research on the seismic performances of the pile body of PCSS piles. This paper presents an experimental study and the associated theoretical and finite element (FE) analyses on the seismic performance of PCSS piles. Three full-scale PCSS pile specimens were tested under lateral cyclic loads with various axial force ratios, and the results are analyzed. Following the tests, a theoretical calculation method is proposed for the bearing capacity of PCSS piles. A FE model for PCSS pile specimens is established and validated against the test observations. Based on this model, a parametric analysis is then conducted. The results show that the PCSS pile specimens all exhibit typical flexural failure. Under a low axial force ratio, the failure mode of PCSS pile specimen is governed by the tensile rupture of prestressing tendons. Under a high axial force ratio, the failure is influenced by the crushing of cover concrete, while the concrete in the core zone remains intact, and there is no outward buckling of prestressing tendons and no rupture of stirrups. Increasing the prestressing tendon ratio can simultaneously improve the bearing and deformation capacity under a lower axial force. Under higher axial force ratios, however, increasing the prestressing tendon ratio or concrete strength can improve the bearing capacity but lead to a decline in deformation capacity. Compared to pretensioned spun high-strength concrete (PHC) piles, PCSS piles exhibit better seismic behavior on aspects of deformation capacity and ductility
A comprehensive approach to developing a multi-epitope vaccine against Mycobacterium tuberculosis: from in silico design to in vitro immunization evaluation
IntroductionThe Bacillus Calmette-Guérin (BCG) vaccine, currently used against tuberculosis (TB), exhibits inconsistent efficacy, highlighting the need for more potent TB vaccines.Materials and methodsIn this study, we employed reverse vaccinology techniques to develop a promising multi-epitope vaccine (MEV) candidate, called PP13138R, for TB prevention. PP13138R comprises 34 epitopes, including B-cell, cytotoxic T lymphocyte, and helper T lymphocyte epitopes. Using bioinformatics and immunoinformatics tools, we assessed the physicochemical properties, structural features, and immunological characteristics of PP13138R.ResultsThe vaccine candidate demonstrated excellent antigenicity, immunogenicity, and solubility without any signs of toxicity or sensitization. In silico analyses revealed that PP13138R interacts strongly with Toll-like receptor 2 and 4, stimulating innate and adaptive immune cells to produce abundant antigen-specific antibodies and cytokines. In vitro experiments further supported the efficacy of PP13138R by significantly increasing the population of IFN-γ+ T lymphocytes and the production of IFN-γ, TNF-α, IL-6, and IL-10 cytokines in active tuberculosis patients, latent tuberculosis infection individuals, and healthy controls, revealing the immunological characteristics and compare the immune responses elicited by the PP13138R vaccine across different stages of Mycobacterium tuberculosis infection.ConclusionThese findings highlight the potential of PP13138R as a promising MEV candidate, characterized by favorable antigenicity, immunogenicity, and solubility, without any toxicity or sensitization
Probing Primordial Gravitational Waves: Ali CMB Polarization Telescope
In this paper, we will give a general introduction to the project of Ali CMB
Polarization Telescope (AliCPT), which is a Sino-US joint project led by the
Institute of High Energy Physics (IHEP) and has involved many different
institutes in China. It is the first ground-based Cosmic Microwave Background
(CMB) polarization experiment in China and an integral part of China's
Gravitational Waves Program. The main scientific goal of AliCPT project is to
probe the primordial gravitational waves (PGWs) originated from the very early
Universe.
The AliCPT project includes two stages. The first stage referred to as
AliCPT-1, is to build a telescope in the Ali region of Tibet with an altitude
of 5,250 meters. Once completed, it will be the worldwide highest ground-based
CMB observatory and open a new window for probing PGWs in northern hemisphere.
AliCPT-1 telescope is designed to have about 7,000 TES detectors at 90GHz and
150GHz. The second stage is to have a more sensitive telescope (AliCPT-2) with
the number of detectors more than 20,000.
Our simulations show that AliCPT will improve the current constraint on the
tensor-to-scalar ratio by one order of magnitude with 3 years' observation.
Besides the PGWs, the AliCPT will also enable a precise measurement on the CMB
rotation angle and provide a precise test on the CPT symmetry. We show 3 years'
observation will improve the current limit by two order of magnitude.Comment: 11 pages, 7 figures, 2 table
ToonTalker: Cross-Domain Face Reenactment
We target cross-domain face reenactment in this paper, i.e., driving a
cartoon image with the video of a real person and vice versa. Recently, many
works have focused on one-shot talking face generation to drive a portrait with
a real video, i.e., within-domain reenactment. Straightforwardly applying those
methods to cross-domain animation will cause inaccurate expression transfer,
blur effects, and even apparent artifacts due to the domain shift between
cartoon and real faces. Only a few works attempt to settle cross-domain face
reenactment. The most related work AnimeCeleb requires constructing a dataset
with pose vector and cartoon image pairs by animating 3D characters, which
makes it inapplicable anymore if no paired data is available. In this paper, we
propose a novel method for cross-domain reenactment without paired data.
Specifically, we propose a transformer-based framework to align the motions
from different domains into a common latent space where motion transfer is
conducted via latent code addition. Two domain-specific motion encoders and two
learnable motion base memories are used to capture domain properties. A source
query transformer and a driving one are exploited to project domain-specific
motion to the canonical space. The edited motion is projected back to the
domain of the source with a transformer. Moreover, since no paired data is
provided, we propose a novel cross-domain training scheme using data from two
domains with the designed analogy constraint. Besides, we contribute a cartoon
dataset in Disney style. Extensive evaluations demonstrate the superiority of
our method over competing methods
A Distance-Aware Replica Adaptive Data Gathering Protocol for Delay Tolerant Mobile Sensor Networks
In Delay Tolerant Mobile Sensor Networks (DTMSNs) that have the inherent features of intermitted connectivity and frequently changing network topology it is reasonable to utilize multi-replica schemes to improve the data gathering performance. However, most existing multi-replica approaches inject a large amount of message copies into the network to increase the probability of message delivery, which may drain each mobile node’s limited battery supply faster and result in too much contention for the restricted resources of the DTMSN, so a proper data gathering scheme needs a trade off between the number of replica messages and network performance. In this paper, we propose a new data gathering protocol called DRADG (for Distance-aware Replica Adaptive Data Gathering protocol), which economizes network resource consumption through making use of a self-adapting algorithm to cut down the number of redundant replicas of messages, and achieves a good network performance by leveraging the delivery probabilities of the mobile sensors as main routing metrics. Simulation results have shown that the proposed DRADG protocol achieves comparable or higher message delivery ratios at the cost of the much lower transmission overhead than several current DTMSN data gathering schemes
Shape-Aware Organ Segmentation by Predicting Signed Distance Maps
In this work, we propose to resolve the issue existing in current deep
learning based organ segmentation systems that they often produce results that
do not capture the overall shape of the target organ and often lack smoothness.
Since there is a rigorous mapping between the Signed Distance Map (SDM)
calculated from object boundary contours and the binary segmentation map, we
exploit the feasibility of learning the SDM directly from medical scans. By
converting the segmentation task into predicting an SDM, we show that our
proposed method retains superior segmentation performance and has better
smoothness and continuity in shape. To leverage the complementary information
in traditional segmentation training, we introduce an approximated Heaviside
function to train the model by predicting SDMs and segmentation maps
simultaneously. We validate our proposed models by conducting extensive
experiments on a hippocampus segmentation dataset and the public MICCAI 2015
Head and Neck Auto Segmentation Challenge dataset with multiple organs. While
our carefully designed backbone 3D segmentation network improves the Dice
coefficient by more than 5% compared to current state-of-the-arts, the proposed
model with SDM learning produces smoother segmentation results with smaller
Hausdorff distance and average surface distance, thus proving the effectiveness
of our method.Comment: AAAI 202
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