Recent studies show that, despite being effective on numerous tasks, text processing algorithms may be vulnerable to deliberate attacks. However, the question of whether such weaknesses can directly lead to security threats is still under-explored. To bridge this gap, we conducted vulnerability tests on Text-to-SQL, a technique that builds natural language interfaces for databases. Empirically, we showed that the Text-to-SQL modules of two commercial black boxes (Baidu-UNIT and Codex-powered Ai2sql) can be manipulated to produce malicious code, potentially leading to data breaches and Denial of Service. This is the first demonstration of the danger of NLP models being exploited as attack vectors in the wild. Moreover, experiments involving four open-source frameworks verified that simple backdoor attacks can achieve a 100% success rate on Text-to-SQL systems with almost no prediction performance impact. By reporting these findings and suggesting practical defences, we call for immediate attention from the NLP community to the identification and remediation of software security issues.
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我们提出了一个新颖的框架,按需运动产生(ODMO),用于生成现实和多样化的长期3D人体运动序列,该序列仅以具有额外的自定义能力的动作类型为条件。 ODMO在三个公共数据集(HumanAct12,UESTC和MOCAP)上进行评估时,对所有传统运动评估指标的SOTA方法显示了改进。此外,我们提供定性评估和定量指标,这些指标证明了我们框架提供的几种首要的自定义功能,包括模式发现,插值和轨迹自定义。这些功能大大扩大了此类运动产生模型的潜在应用的范围。编码器和解码器体系结构中的创新启用了新颖的按需生成能力:(i)编码器:在低维的潜在空间中利用对比度学习来创建运动序列的层次结构嵌入,不仅是不同动作的代码,类型形成不同的组,但在动作类型中,类似的固有模式(运动样式)聚集在一起的代码,使它们容易发现; (ii)解码器:使用层次解码策略,该策略首先重建运动轨迹,然后用于重建整个运动序列。这样的架构可以有效地控制轨迹控制。我们的代码发布在GitHub页面:https://github.com/roychowdhuryresearch/odmo
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虽然现代形象翻译技术可以创造光电态合成图像,但它们具有有限的风格可控性,因此可能遭受翻译误差。在这项工作中,我们表明激活功能是控制图像合成方向的重要组件之一。具体地,我们明确证明整流器的斜率参数可以改变数据分布并独立使用以控制翻译方向。为了提高风格可控性,提出了两种简单但有效的技术,包括自适应Relu(Adarelu)和结构自适应功能。 Adarelu可以根据目标风格动态调整斜率参数,并且可以用于通过与自适应实例归一化(Adain)组合来提高可控性。同时,结构适应性功能使整流器能够更有效地操纵特征图的结构。它由所提出的结构卷积(Struconv)组成,一种有效的卷积模块,可以根据AADAIN指定的平均值和方差选择要激活的区域。广泛的实验表明,所提出的技术可以大大提高基于风格的图像转换任务的网络可控性和输出分集。
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Unlike traditional distributed machine learning, federated learning stores data locally for training and then aggregates the models on the server, which solves the data security problem that may arise in traditional distributed machine learning. However, during the training process, the transmission of model parameters can impose a significant load on the network bandwidth. It has been pointed out that the vast majority of model parameters are redundant during model parameter transmission. In this paper, we explore the data distribution law of selected partial model parameters on this basis, and propose a deep hierarchical quantization compression algorithm, which further compresses the model and reduces the network load brought by data transmission through the hierarchical quantization of model parameters. And we adopt a dynamic sampling strategy for the selection of clients to accelerate the convergence of the model. Experimental results on different public datasets demonstrate the effectiveness of our algorithm.
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Supervised machine learning-based medical image computing applications necessitate expert label curation, while unlabelled image data might be relatively abundant. Active learning methods aim to prioritise a subset of available image data for expert annotation, for label-efficient model training. We develop a controller neural network that measures priority of images in a sequence of batches, as in batch-mode active learning, for multi-class segmentation tasks. The controller is optimised by rewarding positive task-specific performance gain, within a Markov decision process (MDP) environment that also optimises the task predictor. In this work, the task predictor is a segmentation network. A meta-reinforcement learning algorithm is proposed with multiple MDPs, such that the pre-trained controller can be adapted to a new MDP that contains data from different institutes and/or requires segmentation of different organs or structures within the abdomen. We present experimental results using multiple CT datasets from more than one thousand patients, with segmentation tasks of nine different abdominal organs, to demonstrate the efficacy of the learnt prioritisation controller function and its cross-institute and cross-organ adaptability. We show that the proposed adaptable prioritisation metric yields converging segmentation accuracy for the novel class of kidney, unseen in training, using between approximately 40\% to 60\% of labels otherwise required with other heuristic or random prioritisation metrics. For clinical datasets of limited size, the proposed adaptable prioritisation offers a performance improvement of 22.6\% and 10.2\% in Dice score, for tasks of kidney and liver vessel segmentation, respectively, compared to random prioritisation and alternative active sampling strategies.
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Three-dimensional (3D) freehand ultrasound (US) reconstruction without a tracker can be advantageous over its two-dimensional or tracked counterparts in many clinical applications. In this paper, we propose to estimate 3D spatial transformation between US frames from both past and future 2D images, using feed-forward and recurrent neural networks (RNNs). With the temporally available frames, a further multi-task learning algorithm is proposed to utilise a large number of auxiliary transformation-predicting tasks between them. Using more than 40,000 US frames acquired from 228 scans on 38 forearms of 19 volunteers in a volunteer study, the hold-out test performance is quantified by frame prediction accuracy, volume reconstruction overlap, accumulated tracking error and final drift, based on ground-truth from an optical tracker. The results show the importance of modelling the temporal-spatially correlated input frames as well as output transformations, with further improvement owing to additional past and/or future frames. The best performing model was associated with predicting transformation between moderately-spaced frames, with an interval of less than ten frames at 20 frames per second (fps). Little benefit was observed by adding frames more than one second away from the predicted transformation, with or without LSTM-based RNNs. Interestingly, with the proposed approach, explicit within-sequence loss that encourages consistency in composing transformations or minimises accumulated error may no longer be required. The implementation code and volunteer data will be made publicly available ensuring reproducibility and further research.
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Artificial Intelligence (AI) is having a tremendous impact across most areas of science. Applications of AI in healthcare have the potential to improve our ability to detect, diagnose, prognose, and intervene on human disease. For AI models to be used clinically, they need to be made safe, reproducible and robust, and the underlying software framework must be aware of the particularities (e.g. geometry, physiology, physics) of medical data being processed. This work introduces MONAI, a freely available, community-supported, and consortium-led PyTorch-based framework for deep learning in healthcare. MONAI extends PyTorch to support medical data, with a particular focus on imaging, and provide purpose-specific AI model architectures, transformations and utilities that streamline the development and deployment of medical AI models. MONAI follows best practices for software-development, providing an easy-to-use, robust, well-documented, and well-tested software framework. MONAI preserves the simple, additive, and compositional approach of its underlying PyTorch libraries. MONAI is being used by and receiving contributions from research, clinical and industrial teams from around the world, who are pursuing applications spanning nearly every aspect of healthcare.
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在域移位下,跨域几个射击对象检测旨在通过一些注释的目标数据适应目标域中的对象检测器。存在两个重大挑战:(1)高度不足的目标域数据; (2)潜在的过度适应和误导性是由不当放大的目标样本而没有任何限制引起的。为了应对这些挑战,我们提出了一种由两个部分组成的自适应方法。首先,我们提出了一种自适应优化策略,以选择类似于目标样本的增强数据,而不是盲目增加数量。具体而言,我们过滤了增强的候选者,这些候选者在一开始就显着偏离了目标特征分布。其次,为了进一步释放数据限制,我们提出了多级域感知数据增强,以增加增强数据的多样性和合理性,从而利用了跨图像前景 - 背景混合物。实验表明,所提出的方法在多个基准测试中实现了最先进的性能。
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在医学图像分析中需要进行几次学习的能力是对支持图像数据的有效利用,该数据被标记为对新类进行分类或细分新类,该任务否则需要更多的培训图像和专家注释。这项工作描述了一种完全3D原型的几种分段算法,因此,训练有素的网络可以有效地适应培训中缺乏的临床有趣结构,仅使用来自不同研究所的几个标记图像。首先,为了弥补机构在新型类别的情节适应中的广泛认识的空间变异性,新型的空间注册机制被整合到原型学习中,由分割头和空间对齐模块组成。其次,为了帮助训练观察到的不完美比对,提出了支持掩模调节模块,以进一步利用支持图像中可用的注释。使用589个骨盆T2加权MR图像的数据集分割了八个对介入计划的解剖结构的应用,该实验是针对介入八个机构的八个解剖结构的应用。结果证明了3D公式中的每种,空间登记和支持掩模条件的功效,所有这些条件都独立或集体地做出了积极的贡献。与先前提出的2D替代方案相比,不管支持数据来自相同还是不同的机构,都具有统计学意义的少量分割性能。
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前列腺活检和图像引导的治疗程序通常是在与磁共振图像(MRI)的超声指导下进行的。准确的图像融合依赖于超声图像上前列腺的准确分割。然而,超声图像中降低的信噪比和工件(例如,斑点和阴影)限制了自动前列腺分割技术的性能,并将这些方法推广到新的图像域是本质上很难的。在这项研究中,我们通过引入一种新型的2.5D深神经网络来解决这些挑战,用于超声图像上的前列腺分割。我们的方法通过组合有监督的域适应技术和知识蒸馏损失,解决了转移学习和填充方法的局限性(即,在更新模型权重时,在更新模型权重时的性能下降)。知识蒸馏损失允许保留先前学习的知识,并在新数据集上的模型填充后降低性能下降。此外,我们的方法依赖于注意模块,该模块认为模型特征定位信息以提高分割精度。我们对一个机构的764名受试者进行了培训,并仅使用后续机构中的十个受试者对我们的模型进行了审核。我们分析了方法在三个大型数据集上的性能,其中包括来自三个不同机构的2067名受试者。我们的方法达到了平均骰子相似性系数(骰子)为$ 94.0 \ pm0.03 $,而Hausdorff距离(HD95)为2.28 $ mm $,在第一机构的独立受试者中。此外,我们的模型在其他两个机构的研究中都很好地概括了(骰子:$ 91.0 \ pm0.03 $; hd95:3.7 $ mm $ and Dice:$ 82.0 \ pm0.03 $; hd95 $; hd95:7.1 $ mm $)。
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