78 research outputs found
Effective Image Tampering Localization via Enhanced Transformer and Co-attention Fusion
Powerful manipulation techniques have made digital image forgeries be easily
created and widespread without leaving visual anomalies. The blind localization
of tampered regions becomes quite significant for image forensics. In this
paper, we propose an effective image tampering localization network (EITLNet)
based on a two-branch enhanced transformer encoder with attention-based feature
fusion. Specifically, a feature enhancement module is designed to enhance the
feature representation ability of the transformer encoder. The features
extracted from RGB and noise streams are fused effectively by the coordinate
attention-based fusion module at multiple scales. Extensive experimental
results verify that the proposed scheme achieves the state-of-the-art
generalization ability and robustness in various benchmark datasets. Code will
be public at https://github.com/multimediaFor/EITLNet
Effective Image Tampering Localization via Semantic Segmentation Network
With the widespread use of powerful image editing tools, image tampering
becomes easy and realistic. Existing image forensic methods still face
challenges of low accuracy and robustness. Note that the tampered regions are
typically semantic objects, in this letter we propose an effective image
tampering localization scheme based on deep semantic segmentation network.
ConvNeXt network is used as an encoder to learn better feature representation.
The multi-scale features are then fused by Upernet decoder for achieving better
locating capability. Combined loss and effective data augmentation are adopted
to ensure effective model training. Extensive experimental results confirm that
localization performance of our proposed scheme outperforms other
state-of-the-art ones
Progressive Feedback-Enhanced Transformer for Image Forgery Localization
Blind detection of the forged regions in digital images is an effective
authentication means to counter the malicious use of local image editing
techniques. Existing encoder-decoder forensic networks overlook the fact that
detecting complex and subtle tampered regions typically requires more feedback
information. In this paper, we propose a Progressive FeedbACk-enhanced
Transformer (ProFact) network to achieve coarse-to-fine image forgery
localization. Specifically, the coarse localization map generated by an initial
branch network is adaptively fed back to the early transformer encoder layers
for enhancing the representation of positive features while suppressing
interference factors. The cascaded transformer network, combined with a
contextual spatial pyramid module, is designed to refine discriminative
forensic features for improving the forgery localization accuracy and
reliability. Furthermore, we present an effective strategy to automatically
generate large-scale forged image samples close to real-world forensic
scenarios, especially in realistic and coherent processing. Leveraging on such
samples, a progressive and cost-effective two-stage training protocol is
applied to the ProFact network. The extensive experimental results on nine
public forensic datasets show that our proposed localizer greatly outperforms
the state-of-the-art on the generalization ability and robustness of image
forgery localization. Code will be publicly available at
https://github.com/multimediaFor/ProFact
The averaged potential gradient approach to model the rejection of electrolyte solutions using nanofiltration: Model development and assessment for highly concentrated feed solutions
International audienceSome of the recent publications in nanofiltration modelling converge on the importance of dielectric effects and numerous models have been developed in order to take them into account. However several works reported lately in the literature suggest a screening of image charges effect at high electrolyte concentration and the predominance of the Born effect, due to the change of dielectric constant inside the confined nanopore regarding that of the feed solution. In pursuit of an exhaustive and simple model for nanofiltration, a new approach is developed that account for both dielectric phenomena. Based on the Steric, Electric and Dielectric Exclusion (SEDE), the introduction of an average potential gradient approximation is shown to greatly improve the computational performance of the model without being detrimental to its predictive accuracy. The results obtained with this simplified model (SEDE-APG) are compared to the original SEDE model and an excellent agreement is obtained even in the case of electrolyte mixtures. Ultimately this model is confronted to experimental data of separation obtained for moderately to highly concentrated feed flows and exhibits promising result
Computation of the hindrance factor for the diffusion for nanoconfined ions: molecular dynamics simulations versus continuum-based models
Special Issue: Thermodynamics 2011 ConferenceInternational audienceWe report the self-diffusion coefficients and hindrance factor for the diffusion of ions into cylindrical hydrophilic silica nanopores (hydrated silica) determined from molecular dynamics (MD) simulations. We make a comparison with the hindered diffusion coefficients used in continuum-based models of nanofiltration (NF). Hindrance factors for diffusion estimated from the macroscopic hydrodynamic theory were found to be in fair quantitative agreement with MD simulations for a protonated pore, but they strongly overestimate diffusion inside a deprotonated pore
How do East African Communities Cope with the Impacts of Prosopis juliflora (Mesquite) Invasion? A Review
Prosopis juliflora is an evergreen invasive plant native to South America, the Caribbean, and Central America. The plant is well adapted to harsh environmental conditions. As a result, it has spread to most arid and semi-arid areas of the world causing both positive and negative impacts. This study reviewed the adaptation/coping strategies adopted by East African communities as a result of the invasion by the plant. The review results showed that East African communities cope by using the plant for human food and animal feed, leasing the infested land, renting land from uninvaded areas, clearing the plant from farming, grazing land, waterways, paths and homesteads, and using it as fuel in form of firewood and charcoal among others. The communities living in the infested areas now almost entirely depend on the plant for livelihood. Some of the employed adaptations/ coping strategies were found to be inadequate and to have negative environmental impacts. In order to enhance the adaptations/ coping strategies, we recommend commercialization of the plant’s seed for animal feed and human food production, sensitization of the communities on the medicinal use of the plant and that programs to manage the plant should take into account the adaptations the communities have developed over time to avoid negative impacts on the communities’ livelihoods. Keywords: Prosopis juliflora; Coping strategies; East Africa; Invasion; Po
Group Network Hawkes Process
In this work, we study the event occurrences of individuals interacting in a
network. To characterize the dynamic interactions among the individuals, we
propose a group network Hawkes process (GNHP) model whose network structure is
observed and fixed. In particular, we introduce a latent group structure among
individuals to account for the heterogeneous user-specific characteristics. A
maximum likelihood approach is proposed to simultaneously cluster individuals
in the network and estimate model parameters. A fast EM algorithm is
subsequently developed by utilizing the branching representation of the
proposed GNHP model. Theoretical properties of the resulting estimators of
group memberships and model parameters are investigated under both settings
when the number of latent groups is over-specified or correctly specified.
A data-driven criterion that can consistently identify the true under mild
conditions is derived. Extensive simulation studies and an application to a
data set collected from Sina Weibo are used to illustrate the effectiveness of
the proposed methodology.Comment: 35 page
Knowledge Editing for Large Language Models: A Survey
Large language models (LLMs) have recently transformed both the academic and
industrial landscapes due to their remarkable capacity to understand, analyze,
and generate texts based on their vast knowledge and reasoning ability.
Nevertheless, one major drawback of LLMs is their substantial computational
cost for pre-training due to their unprecedented amounts of parameters. The
disadvantage is exacerbated when new knowledge frequently needs to be
introduced into the pre-trained model. Therefore, it is imperative to develop
effective and efficient techniques to update pre-trained LLMs. Traditional
methods encode new knowledge in pre-trained LLMs through direct fine-tuning.
However, naively re-training LLMs can be computationally intensive and risks
degenerating valuable pre-trained knowledge irrelevant to the update in the
model. Recently, Knowledge-based Model Editing (KME) has attracted increasing
attention, which aims to precisely modify the LLMs to incorporate specific
knowledge, without negatively influencing other irrelevant knowledge. In this
survey, we aim to provide a comprehensive and in-depth overview of recent
advances in the field of KME. We first introduce a general formulation of KME
to encompass different KME strategies. Afterward, we provide an innovative
taxonomy of KME techniques based on how the new knowledge is introduced into
pre-trained LLMs, and investigate existing KME strategies while analyzing key
insights, advantages, and limitations of methods from each category. Moreover,
representative metrics, datasets, and applications of KME are introduced
accordingly. Finally, we provide an in-depth analysis regarding the
practicality and remaining challenges of KME and suggest promising research
directions for further advancement in this field.Comment: 33 page
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