31 research outputs found
Label Enhanced Event Detection with Heterogeneous Graph Attention Networks
Event Detection (ED) aims to recognize instances of specified types of event
triggers in text. Different from English ED, Chinese ED suffers from the
problem of word-trigger mismatch due to the uncertain word boundaries. Existing
approaches injecting word information into character-level models have achieved
promising progress to alleviate this problem, but they are limited by two
issues. First, the interaction between characters and lexicon words is not
fully exploited. Second, they ignore the semantic information provided by event
labels. We thus propose a novel architecture named Label enhanced Heterogeneous
Graph Attention Networks (L-HGAT). Specifically, we transform each sentence
into a graph, where character nodes and word nodes are connected with different
types of edges, so that the interaction between words and characters is fully
reserved. A heterogeneous graph attention networks is then introduced to
propagate relational message and enrich information interaction. Furthermore,
we convert each label into a trigger-prototype-based embedding, and design a
margin loss to guide the model distinguish confusing event labels. Experiments
on two benchmark datasets show that our model achieves significant improvement
over a range of competitive baseline methods
Federated Learning over a Wireless Network: Distributed User Selection through Random Access
User selection has become crucial for decreasing the communication costs of
federated learning (FL) over wireless networks. However, centralized user
selection causes additional system complexity. This study proposes a network
intrinsic approach of distributed user selection that leverages the radio
resource competition mechanism in random access. Taking the carrier sensing
multiple access (CSMA) mechanism as an example of random access, we manipulate
the contention window (CW) size to prioritize certain users for obtaining radio
resources in each round of training. Training data bias is used as a target
scenario for FL with user selection. Prioritization is based on the distance
between the newly trained local model and the global model of the previous
round. To avoid excessive contribution by certain users, a counting mechanism
is used to ensure fairness. Simulations with various datasets demonstrate that
this method can rapidly achieve convergence similar to that of the centralized
user selection approach
Adaptive Data Augmentation for Aspect Sentiment Quad Prediction
Aspect sentiment quad prediction (ASQP) aims to predict the quad sentiment
elements for a given sentence, which is a critical task in the field of
aspect-based sentiment analysis. However, the data imbalance issue has not
received sufficient attention in ASQP task. In this paper, we divide the issue
into two-folds, quad-pattern imbalance and aspect-category imbalance, and
propose an Adaptive Data Augmentation (ADA) framework to tackle the imbalance
issue. Specifically, a data augmentation process with a condition function
adaptively enhances the tail quad patterns and aspect categories, alleviating
the data imbalance in ASQP. Following previous studies, we also further explore
the generative framework for extracting complete quads by introducing the
category prior knowledge and syntax-guided decoding target. Experimental
results demonstrate that data augmentation for imbalance in ASQP task can
improve the performance, and the proposed ADA method is superior to naive data
oversampling.Comment: Accepted by ICASSP 2024, 5 page
Enhancing Multimodal Entity and Relation Extraction with Variational Information Bottleneck
This paper studies the multimodal named entity recognition (MNER) and
multimodal relation extraction (MRE), which are important for multimedia social
platform analysis. The core of MNER and MRE lies in incorporating evident
visual information to enhance textual semantics, where two issues inherently
demand investigations. The first issue is modality-noise, where the
task-irrelevant information in each modality may be noises misleading the task
prediction. The second issue is modality-gap, where representations from
different modalities are inconsistent, preventing from building the semantic
alignment between the text and image. To address these issues, we propose a
novel method for MNER and MRE by Multi-Modal representation learning with
Information Bottleneck (MMIB). For the first issue, a refinement-regularizer
probes the information-bottleneck principle to balance the predictive evidence
and noisy information, yielding expressive representations for prediction. For
the second issue, an alignment-regularizer is proposed, where a mutual
information-based item works in a contrastive manner to regularize the
consistent text-image representations. To our best knowledge, we are the first
to explore variational IB estimation for MNER and MRE. Experiments show that
MMIB achieves the state-of-the-art performances on three public benchmarks
FFT: Towards Harmlessness Evaluation and Analysis for LLMs with Factuality, Fairness, Toxicity
The widespread of generative artificial intelligence has heightened concerns
about the potential harms posed by AI-generated texts, primarily stemming from
factoid, unfair, and toxic content. Previous researchers have invested much
effort in assessing the harmlessness of generative language models. However,
existing benchmarks are struggling in the era of large language models (LLMs),
due to the stronger language generation and instruction following capabilities,
as well as wider applications. In this paper, we propose FFT, a new benchmark
with 2116 elaborated-designed instances, for LLM harmlessness evaluation with
factuality, fairness, and toxicity. To investigate the potential harms of LLMs,
we evaluate 9 representative LLMs covering various parameter scales, training
stages, and creators. Experiments show that the harmlessness of LLMs is still
under-satisfactory, and extensive analysis derives some insightful findings
that could inspire future research for harmless LLM research.Comment: Work in progres
New Automatic Search Tool for Impossible Differentials and Zero-Correlation Linear Approximations
Impossible differential and zero-correlation linear cryptanalysis are two of the most powerful cryptanalysis methods in the field of symmetric key cryptography.
There are several automatic tools to search such trails for ciphers with S-boxes. These tools focus on the properties of linear layers, and idealize the underlying S-boxes, i.e., assume any input and output difference pairs are possible. In reality, such S-box never exists, and the possible output differences with any fixed input difference can be at most half of the entire space. Hence, some of the possible differential trails under the ideal world become impossible in reality, possibly resulting in impossible differential trails for more rounds. In this paper, we firstly take the differential and linear properties of non-linear components such as S-box into consideration and propose a new automatic tool to search impossible differential trails for ciphers with S-box. We then generalize the tool to modulo addition, and apply it to ARX ciphers.
To demonstrate the usefulness of the tool, we apply it to HIGHT, SHACAL-2, LEA, LBlock. As a result, it improves the best existing results of each cipher
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Tuning Oxygen Redox Reaction through the Inductive Effect with Proton Insertion in Li-Rich Oxides.
As a parent compound of Li-rich electrodes, Li2MnO3 exhibits high capacity during the initial charge; however, it suffers notoriously low Coulombic efficiency due to oxygen and surface activities. Here, we successfully optimize the oxygen activities toward reversible oxygen redox reactions by intentionally introducing protons into lithium octahedral vacancies in the Li2MnO3 system with its original structural integrity maintained. Combining structural probes, theoretical calculations, and resonant inelastic X-ray scattering results, a moderate coupling between the introduced protons and lattice oxygen at the oxidized state is revealed, which stabilizes the oxygen activities during charging. Such a coupling leads to an unprecedented initial Coulombic efficiency (99.2%) with a greatly improved discharge capacity of 302 mAh g-1 in the protonated Li2MnO3 electrodes. These findings directly demonstrate an effective concept for controlling oxygen activities in Li-rich systems, which is critical for developing high-energy cathodes in batteries
Oxidation of Enrofloxacin with Permanganate: Kinetics, Multivariate Effects, Identification of Oxidation Products, and Determination of Residual Antibacterial Activity
Permanganate [Mn(VII)] chemistry oxidation of fluoroquinolone (FQ) antibiotic enrofloxacin (ENR) in water is investigated with respect to the kinetics, pH effect, buffer effect, and the evaluation of residual antibacterial activity after oxidative treatment. The degradation of ENR by Mn(VII) obeyed a secondary-order kinetics. Modern high-resolution tandem mass spectrometry coupled with high performance liquid chromatography was used to analyze the structures of degradation products. Four main oxidation products were identified at different pH values. Several influencing factors, pH value, and buffer obviously affect reaction rate and products relative abundance. Autocatalysis taking place at slightly acidic pH promotes the reaction but has no effect on the product types. A plausible oxidation pathway for enrofloxacin with Mn(VII) was proposed. The oxidation took place at the piperazine ring. Structural changes to the piperazine ring include N-dealkylation, hydroxylation, and hydrolysis. Residual antibacterial activity of the oxidative reaction solutions against nonresistant Escherichia coli reference strain DH5α is evaluated by means of quantitative bioassays. It is noticed that the oxidation products exhibited negligible antibacterial activity just when the structures of the products changed