已知新生儿皮质表面受早产的影响,随后对皮质组织的变化与较差的神经发育结局有关。深层生成模型有可能导致临床上可解释的疾病模型,但是在皮质表面开发这些模型是具有挑战性的,因为已建立的学习卷积过滤器的技术不适当地不适合非弹性拓扑。为了缩小这一差距,我们使用混合模型CNN(MONET)实现了基于表面的自行车,以在皮质成熟度不同阶段之间翻译球形新生儿皮质表面特征(曲率和T1W/T2W皮质髓磷脂)。结果表明,我们的方法能够可靠地预测妊娠后期皮质组织单个模式的变化,并通过与纵向数据进行比较验证。并通过与训练有素的术语/早产子进行比较来验证早产和妊娠期(> 37周妊娠)之间的外观。皮质成熟的模拟差异与文献中的观察结果一致。
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我们提出了Cortexode,这是一种用于皮质表面重建的深度学习框架。 Cortexode利用神经普通微分方程(ODE)通过学习差异流来使输入表面变形为目标形状。表面上的点的轨迹将其建模为ODE,其中其坐标的衍生物通过可学习的Lipschitz-Conluble变形网络进行了参数化。这为预防自身干扰提供了理论保证。 Cortexode可以集成到基于自动学习的管道上,该管道可在不到5秒钟内有效地重建皮质表面。该管道利用3D U-NET来预测大脑磁共振成像(MRI)扫描的白质分割,并进一步生成代表初始表面的签名距离函数。引入快速拓扑校正以确保对球体的同构。遵循等曲面提取步骤,对两个Cortexode模型进行了训练,以分别将初始表面变形为白质和曲面。在包括新生儿(25-45周),年轻人(22-36岁)和老年受试者(55-90岁)(55-90岁)(55-90岁)的各个年龄段的大规模神经图像数据集上对拟议的管道进行评估。我们的实验表明,与常规处理管道相比,基于Cortexode的管道可以达到平均几何误差的平均几何误差小于0.2mm的平均几何误差。
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随着各种公开的AI伦理原则的共识,差距仍然可以随时采用设计和开发负责任的AI系统。我们研究了来自澳大利亚国家科学研究机构(CSIRO)的研究人员和工程师的实践和经验,他们参与设计和开发AI系统的一系列目的。半结构化访谈用于检查参与者的做法如何与澳大利亚政府提出的一套高级AI伦理原则涉及并对齐。原则包括:隐私保护和安全,可靠性和安全性,透明度和解释性,公平性,竞争性,责任,人以人为本的价值观和人类,社会与环境福祉。研究了研究人员和工程师的见解以及在原则的实际应用中为它们提供的挑战。最后,提供了一系列组织响应,以支持实施高级AI道德原则。
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具有更多数据,计算和参数的缩放语言模型在自然语言处理方面取得了重大进展。例如,由于缩放,GPT-3能够在内心学习任务上实现强烈结果。但是,培训这些大密度模型需要大量的计算资源。在本文中,我们提出并开发了名为Glam(通用语言模型)的语言模型系列,它使用稀疏激活的专家架构来规模模型容量,同时与致密变体相比,也产生显着更少的训练成本。最大的Glam具有1.2万亿参数,比GPT-3大约为7倍。它仅消耗了用于训练GPT-3的1/3的能量,并且需要一半的计算拖鞋进行推理,同时仍然在29个NLP任务中实现更好的整体零射击和一次性性能。
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Recent advances in open-domain question answering (ODQA) have demonstrated impressive accuracy on standard Wikipedia style benchmarks. However, it is less clear how robust these models are and how well they perform when applied to real-world applications in drastically different domains. While there has been some work investigating how well ODQA models perform when tested for out-of-domain (OOD) generalization, these studies have been conducted only under conservative shifts in data distribution and typically focus on a single component (ie. retrieval) rather than an end-to-end system. In response, we propose a more realistic and challenging domain shift evaluation setting and, through extensive experiments, study end-to-end model performance. We find that not only do models fail to generalize, but high retrieval scores often still yield poor answer prediction accuracy. We then categorize different types of shifts and propose techniques that, when presented with a new dataset, predict if intervention methods are likely to be successful. Finally, using insights from this analysis, we propose and evaluate several intervention methods which improve end-to-end answer F1 score by up to 24 points.
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Differentiable Search Indices (DSIs) encode a corpus of documents in the parameters of a model and use the same model to map queries directly to relevant document identifiers. Despite the strong performance of DSI models, deploying them in situations where the corpus changes over time is computationally expensive because reindexing the corpus requires re-training the model. In this work, we introduce DSI++, a continual learning challenge for DSI to incrementally index new documents while being able to answer queries related to both previously and newly indexed documents. Across different model scales and document identifier representations, we show that continual indexing of new documents leads to considerable forgetting of previously indexed documents. We also hypothesize and verify that the model experiences forgetting events during training, leading to unstable learning. To mitigate these issues, we investigate two approaches. The first focuses on modifying the training dynamics. Flatter minima implicitly alleviate forgetting, so we optimize for flatter loss basins and show that the model stably memorizes more documents (+12\%). Next, we introduce a generative memory to sample pseudo-queries for documents and supplement them during continual indexing to prevent forgetting for the retrieval task. Extensive experiments on novel continual indexing benchmarks based on Natural Questions (NQ) and MS MARCO demonstrate that our proposed solution mitigates forgetting by a significant margin. Concretely, it improves the average Hits@10 by $+21.1\%$ over competitive baselines for NQ and requires $6$ times fewer model updates compared to re-training the DSI model for incrementally indexing five corpora in a sequence.
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This volume contains revised versions of the papers selected for the third volume of the Online Handbook of Argumentation for AI (OHAAI). Previously, formal theories of argument and argument interaction have been proposed and studied, and this has led to the more recent study of computational models of argument. Argumentation, as a field within artificial intelligence (AI), is highly relevant for researchers interested in symbolic representations of knowledge and defeasible reasoning. The purpose of this handbook is to provide an open access and curated anthology for the argumentation research community. OHAAI is designed to serve as a research hub to keep track of the latest and upcoming PhD-driven research on the theory and application of argumentation in all areas related to AI.
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Recent work has reported that AI classifiers trained on audio recordings can accurately predict severe acute respiratory syndrome coronavirus 2 (SARSCoV2) infection status. Here, we undertake a large scale study of audio-based deep learning classifiers, as part of the UK governments pandemic response. We collect and analyse a dataset of audio recordings from 67,842 individuals with linked metadata, including reverse transcription polymerase chain reaction (PCR) test outcomes, of whom 23,514 tested positive for SARS CoV 2. Subjects were recruited via the UK governments National Health Service Test-and-Trace programme and the REal-time Assessment of Community Transmission (REACT) randomised surveillance survey. In an unadjusted analysis of our dataset AI classifiers predict SARS-CoV-2 infection status with high accuracy (Receiver Operating Characteristic Area Under the Curve (ROCAUC) 0.846 [0.838, 0.854]) consistent with the findings of previous studies. However, after matching on measured confounders, such as age, gender, and self reported symptoms, our classifiers performance is much weaker (ROC-AUC 0.619 [0.594, 0.644]). Upon quantifying the utility of audio based classifiers in practical settings, we find them to be outperformed by simple predictive scores based on user reported symptoms.
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The UK COVID-19 Vocal Audio Dataset is designed for the training and evaluation of machine learning models that classify SARS-CoV-2 infection status or associated respiratory symptoms using vocal audio. The UK Health Security Agency recruited voluntary participants through the national Test and Trace programme and the REACT-1 survey in England from March 2021 to March 2022, during dominant transmission of the Alpha and Delta SARS-CoV-2 variants and some Omicron variant sublineages. Audio recordings of volitional coughs, exhalations, and speech were collected in the 'Speak up to help beat coronavirus' digital survey alongside demographic, self-reported symptom and respiratory condition data, and linked to SARS-CoV-2 test results. The UK COVID-19 Vocal Audio Dataset represents the largest collection of SARS-CoV-2 PCR-referenced audio recordings to date. PCR results were linked to 70,794 of 72,999 participants and 24,155 of 25,776 positive cases. Respiratory symptoms were reported by 45.62% of participants. This dataset has additional potential uses for bioacoustics research, with 11.30% participants reporting asthma, and 27.20% with linked influenza PCR test results.
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The polynomial kernels are widely used in machine learning and they are one of the default choices to develop kernel-based classification and regression models. However, they are rarely used and considered in numerical analysis due to their lack of strict positive definiteness. In particular they do not enjoy the usual property of unisolvency for arbitrary point sets, which is one of the key properties used to build kernel-based interpolation methods. This paper is devoted to establish some initial results for the study of these kernels, and their related interpolation algorithms, in the context of approximation theory. We will first prove necessary and sufficient conditions on point sets which guarantee the existence and uniqueness of an interpolant. We will then study the Reproducing Kernel Hilbert Spaces (or native spaces) of these kernels and their norms, and provide inclusion relations between spaces corresponding to different kernel parameters. With these spaces at hand, it will be further possible to derive generic error estimates which apply to sufficiently smooth functions, thus escaping the native space. Finally, we will show how to employ an efficient stable algorithm to these kernels to obtain accurate interpolants, and we will test them in some numerical experiment. After this analysis several computational and theoretical aspects remain open, and we will outline possible further research directions in a concluding section. This work builds some bridges between kernel and polynomial interpolation, two topics to which the authors, to different extents, have been introduced under the supervision or through the work of Stefano De Marchi. For this reason, they wish to dedicate this work to him in the occasion of his 60th birthday.
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