大型基于变压器的预训练的语言模型在各种知识密集的任务上取得了令人印象深刻的表现,并可以在其参数中捕获事实知识。我们认为,考虑到不断增长的知识和资源需求,在模型参数中存储大量知识是亚最佳选择。我们认为,更有效的替代方法是向模型提供对上下文相关的结构化知识的明确访问,并训练它以使用该知识。我们提出了LM核 - 实现这一目标的一般框架 - 允许从外部知识源对语言模型培训的\ textit {解耦},并允许后者更新而不会影响已经训练的模型。实验结果表明,LM核心获得外部知识,在知识探索任务上的最先进的知识增强语言模型中实现了重要而强大的优于性能。可以有效处理知识更新;并在两个下游任务上表现良好。我们还提出了一个彻底的错误分析,突出了LM核的成功和失败。
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从多个域收集的现实世界数据可以在多个属性上具有多个不同的分布变化。但是,域概括(DG)算法的最新进展仅关注对单个属性的特定变化。我们介绍了具有多属性分布变化的数据集,并发现现有的DG算法无法概括。为了解释这一点,我们使用因果图来根据虚假属性与分类标签之间的关系来表征不同类型的变化。每个多属性因果图都需要对观察到的变量进行不同的约束,因此,基于单个固定独立性约束的任何算法都不能在所有变化中正常工作。我们提出了因果自适应约束最小化(CACM),这是一种用于识别正则化的正确独立性约束的新算法。完全合成,MNIST和小型NORB数据集的结果,涵盖了二进制和多价值属性和标签,确认我们的理论主张:正确的独立性约束导致未见域的最高准确性,而不正确的约束则无法做到这一点。我们的结果表明,建模数据生成过程中固有的因果关系的重要性:在许多情况下,如果没有此信息,就不可能知道正确的正规化约束。
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预训练的语言模型(PTLM)已显示出在自然语言任务上表现良好。许多先前的作品都以通过知识图(KGS)标记的关系链接的实体的形式利用结构性常识来协助PTLM。检索方法使用kg作为单独的静态模块,该模块限制了覆盖范围,因为kgs包含有限的知识。生成方法训练PTLMS kg三倍以提高获得知识的规模。但是,对符号KG实体的培训限制了其在涉及自然语言文本的任务中的适用性,在这些任务中,它们忽略了整体上下文。为了减轻这种情况,我们提出了一个以句子为条件的常识性上下文化器(COSE-CO)作为输入,以使其在生成与输入文本的整体上下文相关的任务中通常可用。为了训练Cose-Co,我们提出了一个新的数据集,其中包括句子和常识知识对。 COSE-CO推断出的知识是多种多样的,并且包含了基础KG中不存在的新实体。我们增强了在多选质量质量检查和开放式常识性推理任务中产生的知识,从而改善了CSQA,ARC,QASC和OBQA数据集的当前最佳方法。我们还展示了其在改善释义生成任务的基线模型方面的适用性。
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在这项工作中,我们专注于从自然语言问题中生成SPARQL查询的任务,然后可以在知识图(kgs)上执行。我们假设已经提供了黄金实体和关系,其余的任务是与Sparql词汇一起以正确的顺序排列它们,并输入令牌以产生正确的SPARQL查询。到目前为止,尚未对此任务进行深入探索,因此我们使用BERT嵌入的BART,T5和PGN(指针发电机网络)进行了深入探讨,因此,请在PLM ERA中寻找此任务的新基础,在dbpedia和wikidata kgs上。我们表明T5需要特殊的输入令牌化,但是在LC-Quad 1.0和LC-Quad 2.0数据集上产生最先进的性能,并且从以前的工作中优于特定于任务的模型。此外,这些方法可以为问题进行语义解析,以使输入的一部分需要复制到输出查询,从而在KG语义解析中启用新的范式。
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Research has shown that climate change creates warmer temperatures and drier conditions, leading to longer wildfire seasons and increased wildfire risks in the United States. These factors have in turn led to increases in the frequency, extent, and severity of wildfires in recent years. Given the danger posed by wildland fires to people, property, wildlife, and the environment, there is an urgency to provide tools for effective wildfire management. Early detection of wildfires is essential to minimizing potentially catastrophic destruction. In this paper, we present our work on integrating multiple data sources in SmokeyNet, a deep learning model using spatio-temporal information to detect smoke from wildland fires. Camera image data is integrated with weather sensor measurements and processed by SmokeyNet to create a multimodal wildland fire smoke detection system. We present our results comparing performance in terms of both accuracy and time-to-detection for multimodal data vs. a single data source. With a time-to-detection of only a few minutes, SmokeyNet can serve as an automated early notification system, providing a useful tool in the fight against destructive wildfires.
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With large-scale adaption to biometric based applications, security and privacy of biometrics is utmost important especially when operating in unsupervised online mode. This work proposes a novel approach for generating new artificial fingerprints also called proxy fingerprints that are natural looking, non-invertible, revocable and privacy preserving. These proxy biometrics can be generated from original ones only with the help of a user-specific key. Instead of using the original fingerprint, these proxy templates can be used anywhere with same convenience. The manuscripts walks through an interesting way in which proxy fingerprints of different types can be generated and how they can be combined with use-specific keys to provide revocability and cancelability in case of compromise. Using the proposed approach a proxy dataset is generated from samples belonging to Anguli fingerprint database. Matching experiments were performed on the new set which is 5 times larger than the original, and it was found that their performance is at par with 0 FAR and 0 FRR in the stolen key, safe key scenarios. Other parameters on revocability and diversity are also analyzed for protection performance.
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Recently, online social media has become a primary source for new information and misinformation or rumours. In the absence of an automatic rumour detection system the propagation of rumours has increased manifold leading to serious societal damages. In this work, we propose a novel method for building automatic rumour detection system by focusing on oversampling to alleviating the fundamental challenges of class imbalance in rumour detection task. Our oversampling method relies on contextualised data augmentation to generate synthetic samples for underrepresented classes in the dataset. The key idea exploits selection of tweets in a thread for augmentation which can be achieved by introducing a non-random selection criteria to focus the augmentation process on relevant tweets. Furthermore, we propose two graph neural networks(GNN) to model non-linear conversations on a thread. To enhance the tweet representations in our method we employed a custom feature selection technique based on state-of-the-art BERTweet model. Experiments of three publicly available datasets confirm that 1) our GNN models outperform the the current state-of-the-art classifiers by more than 20%(F1-score); 2) our oversampling technique increases the model performance by more than 9%;(F1-score) 3) focusing on relevant tweets for data augmentation via non-random selection criteria can further improve the results; and 4) our method has superior capabilities to detect rumours at very early stage.
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A number of competing hypotheses have been proposed to explain why small-batch Stochastic Gradient Descent (SGD)leads to improved generalization over the full-batch regime, with recent work crediting the implicit regularization of various quantities throughout training. However, to date, empirical evidence assessing the explanatory power of these hypotheses is lacking. In this paper, we conduct an extensive empirical evaluation, focusing on the ability of various theorized mechanisms to close the small-to-large batch generalization gap. Additionally, we characterize how the quantities that SGD has been claimed to (implicitly) regularize change over the course of training. By using micro-batches, i.e. disjoint smaller subsets of each mini-batch, we empirically show that explicitly penalizing the gradient norm or the Fisher Information Matrix trace, averaged over micro-batches, in the large-batch regime recovers small-batch SGD generalization, whereas Jacobian-based regularizations fail to do so. This generalization performance is shown to often be correlated with how well the regularized model's gradient norms resemble those of small-batch SGD. We additionally show that this behavior breaks down as the micro-batch size approaches the batch size. Finally, we note that in this line of inquiry, positive experimental findings on CIFAR10 are often reversed on other datasets like CIFAR100, highlighting the need to test hypotheses on a wider collection of datasets.
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The compute-intensive nature of neural networks (NNs) limits their deployment in resource-constrained environments such as cell phones, drones, autonomous robots, etc. Hence, developing robust sparse models fit for safety-critical applications has been an issue of longstanding interest. Though adversarial training with model sparsification has been combined to attain the goal, conventional adversarial training approaches provide no formal guarantee that the models would be robust against any rogue samples in a restricted space around a benign sample. Recently proposed verified local robustness techniques provide such a guarantee. This is the first paper that combines the ideas from verified local robustness and dynamic sparse training to develop `SparseVLR'-- a novel framework to search verified locally robust sparse networks. Obtained sparse models exhibit accuracy and robustness comparable to their dense counterparts at sparsity as high as 99%. Furthermore, unlike most conventional sparsification techniques, SparseVLR does not require a pre-trained dense model, reducing the training time by 50%. We exhaustively investigated SparseVLR's efficacy and generalizability by evaluating various benchmark and application-specific datasets across several models.
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In many real-world problems, the learning agent needs to learn a problem's abstractions and solution simultaneously. However, most such abstractions need to be designed and refined by hand for different problems and domains of application. This paper presents a novel top-down approach for constructing state abstractions while carrying out reinforcement learning. Starting with state variables and a simulator, it presents a novel domain-independent approach for dynamically computing an abstraction based on the dispersion of Q-values in abstract states as the agent continues acting and learning. Extensive empirical evaluation on multiple domains and problems shows that this approach automatically learns abstractions that are finely-tuned to the problem, yield powerful sample efficiency, and result in the RL agent significantly outperforming existing approaches.
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