2022-11-15 更新
AdaptKeyBERT: An Attention-Based approach towards Few-Shot \& Zero-Shot Domain Adaptation of KeyBERT
Authors:Aman Priyanshu, Supriti Vijay
Keyword extraction has been an important topic for modern natural language processing. With its applications ranging from ontology generation, fact verification in summarized text, and recommendation systems. While it has had significant data-intensive applications, it is often hampered when the data set is small. Downstream training for keyword extractors is a lengthy process and requires a significant amount of data. Recently, Few-shot Learning (FSL) and Zero-Shot Learning (ZSL) have been proposed to tackle this problem. Therefore, we propose AdaptKeyBERT, a pipeline for training keyword extractors with LLM bases by incorporating the concept of regularized attention into a pre-training phase for downstream domain adaptation. As we believe our work has implications to be utilized in the pipeline of FSL/ZSL and keyword extraction, we open-source our code as well as provide the fine-tuning library of the same name AdaptKeyBERT at \url{https://github.com/AmanPriyanshu/AdaptKeyBERT}.
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Enhancing Few-shot Image Classification with Cosine Transformer
Authors:Quang-Huy Nguyen, Cuong Q. Nguyen, Dung D. Le, Hieu H. Pham, Minh N. Do
This paper addresses the few-shot image classification problem. One notable limitation of few-shot learning is the variation in describing the same category, which might result in a significant difference between small labeled support and large unlabeled query sets. Our approach is to obtain a relation heatmap between the two sets in order to label the latter one in a transductive setting manner. This can be solved by using cross-attention with the scaled dot-product mechanism. However, the magnitude differences between two separate sets of embedding vectors may cause a significant impact on the output attention map and affect model performance. We tackle this problem by improving the attention mechanism with cosine similarity. Specifically, we develop FS-CT (Few-shot Cosine Transformer), a few-shot image classification method based on prototypical embedding and transformer-based framework. The proposed Cosine attention improves FS-CT performances significantly from nearly 5% to over 20% in accuracy compared to the baseline scaled dot-product attention in various scenarios on three few-shot datasets mini-ImageNet, CUB-200, and CIFAR-FS. Additionally, we enhance the prototypical embedding for categorical representation with learnable weights before feeding them to the attention module. Our proposed method FS-CT along with the Cosine attention is simple to implement and can be applied for a wide range of applications. Our codes are available at https://github.com/vinuni-vishc/Few-Shot-Cosine-Transformer
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Retrieval-Augmented Generative Question Answering for Event Argument Extraction
Authors:Xinya Du, Heng Ji
Event argument extraction has long been studied as a sequential prediction problem with extractive-based methods, tackling each argument in isolation. Although recent work proposes generation-based methods to capture cross-argument dependency, they require generating and post-processing a complicated target sequence (template). Motivated by these observations and recent pretrained language models’ capabilities of learning from demonstrations. We propose a retrieval-augmented generative QA model (R-GQA) for event argument extraction. It retrieves the most similar QA pair and augments it as prompt to the current example’s context, then decodes the arguments as answers. Our approach outperforms substantially prior methods across various settings (i.e. fully supervised, domain transfer, and fewshot learning). Finally, we propose a clustering-based sampling strategy (JointEnc) and conduct a thorough analysis of how different strategies influence the few-shot learning performance. The implementations are available at https:// github.com/xinyadu/RGQA
PDF Accepted by EMNLP 2022 (18 pages)
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Meta-learning Adaptive Deep Kernel Gaussian Processes for Molecular Property Prediction
Authors:Wenlin Chen, Austin Tripp, José Miguel Hernández-Lobato
We propose Adaptive Deep Kernel Fitting with Implicit Function Theorem (ADKF-IFT), a novel framework for learning deep kernel Gaussian processes (GPs) by interpolating between meta-learning and conventional deep kernel learning. Our approach employs a bilevel optimization objective where we meta-learn generally useful feature representations across tasks, in the sense that task-specific GP models estimated on top of such features achieve the lowest possible predictive loss on average. We solve the resulting nested optimization problem using the implicit function theorem (IFT). We show that our ADKF-IFT framework contains previously proposed Deep Kernel Learning (DKL) and Deep Kernel Transfer (DKT) as special cases. Although ADKF-IFT is a completely general method, we argue that it is especially well-suited for drug discovery problems and demonstrate that it significantly outperforms previous state-of-the-art methods on a variety of real-world few-shot molecular property prediction tasks and out-of-domain molecular property prediction and optimization tasks.
PDF 24 pages, 7 figures, 7 tables, 1 algorithm
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Few-shot Multimodal Sentiment Analysis based on Multimodal Probabilistic Fusion Prompts
Authors:Xiaocui Yang, Shi Feng, Daling Wang, Pengfei Hong, Soujanya Poria
Multimodal sentiment analysis is a trending topic with the explosion of multimodal content on the web. Present studies in multimodal sentiment analysis rely on large-scale supervised data. Collating supervised data is time-consuming and labor-intensive. As such, it is essential to investigate the problem of few-shot multimodal sentiment analysis. Previous works in few-shot models generally use language model prompts, which can improve performance in low-resource settings. However, the textual prompt ignores the information from other modalities. We propose Multimodal Probabilistic Fusion Prompts, which can provide diverse cues for multimodal sentiment detection. We first design a unified multimodal prompt to reduce the discrepancy in different modal prompts. To improve the robustness of our model, we then leverage multiple diverse prompts for each input and propose a probabilistic method to fuse the output predictions. Extensive experiments conducted on three datasets confirm the effectiveness of our approach.
PDF under review
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Efficient Zero-shot Event Extraction with Context-Definition Alignment
Authors:Hongming Zhang, Wenlin Yao, Dong Yu
Event extraction (EE) is the task of identifying interested event mentions from text. Conventional efforts mainly focus on the supervised setting. However, these supervised models cannot generalize to event types out of the pre-defined ontology. To fill this gap, many efforts have been devoted to the zero-shot EE problem. This paper follows the trend of modeling event-type semantics but moves one step further. We argue that using the static embedding of the event type name might not be enough because a single word could be ambiguous, and we need a sentence to define the type semantics accurately. To model the definition semantics, we use two separate transformer models to project the contextualized event mentions and corresponding definitions into the same embedding space and then minimize their embedding distance via contrastive learning. On top of that, we also propose a warming phase to help the model learn the minor difference between similar definitions. We name our approach Zero-shot Event extraction with Definition (ZED). Experiments on the MAVEN dataset show that our model significantly outperforms all previous zero-shot EE methods with fast inference speed due to the disjoint design. Further experiments also show that ZED can be easily applied to the few-shot setting when the annotation is available and consistently outperforms baseline supervised methods.
PDF Accepted by EMNLP 2022 findings
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Exposing Outlier Exposure: What Can Be Learned From Few, One, and Zero Outlier Images
Authors:Philipp Liznerski, Lukas Ruff, Robert A. Vandermeulen, Billy Joe Franks, Klaus-Robert Müller, Marius Kloft
Due to the intractability of characterizing everything that looks unlike the normal data, anomaly detection (AD) is traditionally treated as an unsupervised problem utilizing only normal samples. However, it has recently been found that unsupervised image AD can be drastically improved through the utilization of huge corpora of random images to represent anomalousness; a technique which is known as Outlier Exposure. In this paper we show that specialized AD learning methods seem unnecessary for state-of-the-art performance, and furthermore one can achieve strong performance with just a small collection of Outlier Exposure data, contradicting common assumptions in the field of AD. We find that standard classifiers and semi-supervised one-class methods trained to discern between normal samples and relatively few random natural images are able to outperform the current state of the art on an established AD benchmark with ImageNet. Further experiments reveal that even one well-chosen outlier sample is sufficient to achieve decent performance on this benchmark (79.3% AUC). We investigate this phenomenon and find that one-class methods are more robust to the choice of training outliers, indicating that there are scenarios where these are still more useful than standard classifiers. Additionally, we include experiments that delineate the scenarios where our results hold. Lastly, no training samples are necessary when one uses the representations learned by CLIP, a recent foundation model, which achieves state-of-the-art AD results on CIFAR-10 and ImageNet in a zero-shot setting.
PDF 47 pages; extended experiments; published in Transactions on Machine Learning Research;
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Few-Shot Learning for Biometric Verification
Authors:Umaid M. Zaffar, Marium Aslam, Muhammad Imran Malik, Saad Bin Ahmed
In machine learning applications, it is common practice to feed as much information as possible. In most cases, the model can handle large data sets that allow to predict more accurately. In the presence of data scarcity, a Few-Shot learning (FSL) approach aims to build more accurate algorithms with limited training data. We propose a novel end-to-end lightweight architecture that verifies biometric data by producing competitive results as compared to state-of-the-art accuracies through Few-Shot learning methods. The dense layers add to the complexity of state-of-the-art deep learning models which inhibits them to be used in low-power applications. In presented approach, a shallow network is coupled with a conventional machine learning technique that exploits hand-crafted features to verify biometric images from multi-modal sources such as signatures, periocular region, iris, face, fingerprints etc. We introduce a self-estimated threshold that strictly monitors False Acceptance Rate (FAR) while generalizing its results hence eliminating user-defined thresholds from ROC curves that are likely to be biased on local data distribution. This hybrid model benefits from few-shot learning to make up for scarcity of data in biometric use-cases. We have conducted extensive experimentation with commonly used biometric datasets. The obtained results provided an effective solution for biometric verification systems.
PDF 19 pages, 7 figures
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Are Hard Examples also Harder to Explain? A Study with Human and Model-Generated Explanations
Authors:Swarnadeep Saha, Peter Hase, Nazneen Rajani, Mohit Bansal
Recent work on explainable NLP has shown that few-shot prompting can enable large pretrained language models (LLMs) to generate grammatical and factual natural language explanations for data labels. In this work, we study the connection between explainability and sample hardness by investigating the following research question - “Are LLMs and humans equally good at explaining data labels for both easy and hard samples?” We answer this question by first collecting human-written explanations in the form of generalizable commonsense rules on the task of Winograd Schema Challenge (Winogrande dataset). We compare these explanations with those generated by GPT-3 while varying the hardness of the test samples as well as the in-context samples. We observe that (1) GPT-3 explanations are as grammatical as human explanations regardless of the hardness of the test samples, (2) for easy examples, GPT-3 generates highly supportive explanations but human explanations are more generalizable, and (3) for hard examples, human explanations are significantly better than GPT-3 explanations both in terms of label-supportiveness and generalizability judgements. We also find that hardness of the in-context examples impacts the quality of GPT-3 explanations. Finally, we show that the supportiveness and generalizability aspects of human explanations are also impacted by sample hardness, although by a much smaller margin than models. Supporting code and data are available at https://github.com/swarnaHub/ExplanationHardness
PDF EMNLP 2022 (11 pages)
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Few-shot Image Generation via Adaptation-Aware Kernel Modulation
Authors:Yunqing Zhao, Keshigeyan Chandrasegaran, Milad Abdollahzadeh, Ngai-Man Cheung
Few-shot image generation (FSIG) aims to learn to generate new and diverse samples given an extremely limited number of samples from a domain, e.g., 10 training samples. Recent work has addressed the problem using transfer learning approach, leveraging a GAN pretrained on a large-scale source domain dataset and adapting that model to the target domain based on very limited target domain samples. Central to recent FSIG methods are knowledge preserving criteria, which aim to select a subset of source model’s knowledge to be preserved into the adapted model. However, a major limitation of existing methods is that their knowledge preserving criteria consider only source domain/source task, and they fail to consider target domain/adaptation task in selecting source model’s knowledge, casting doubt on their suitability for setups of different proximity between source and target domain. Our work makes two contributions. As our first contribution, we re-visit recent FSIG works and their experiments. Our important finding is that, under setups which assumption of close proximity between source and target domains is relaxed, existing state-of-the-art (SOTA) methods which consider only source domain/source task in knowledge preserving perform no better than a baseline fine-tuning method. To address the limitation of existing methods, as our second contribution, we propose Adaptation-Aware kernel Modulation (AdAM) to address general FSIG of different source-target domain proximity. Extensive experimental results show that the proposed method consistently achieves SOTA performance across source/target domains of different proximity, including challenging setups when source and target domains are more apart. Project Page: https://yunqing-me.github.io/AdAM/
PDF The Thirty-Sixth Annual Conference on Neural Information Processing Systems (NeurIPS 2022), 14 pages
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