Transformer-based models, capable of learning better global dependencies, have recently demonstrated exceptional representation learning capabilities in computer vision and medical image analysis. Transformer reformats the image into separate patches and realize global communication via the self-attention mechanism. However, positional information between patches is hard to preserve in such 1D sequences, and loss of it can lead to sub-optimal performance when dealing with large amounts of heterogeneous tissues of various sizes in 3D medical image segmentation. Additionally, current methods are not robust and efficient for heavy-duty medical segmentation tasks such as predicting a large number of tissue classes or modeling globally inter-connected tissues structures. Inspired by the nested hierarchical structures in vision transformer, we proposed a novel 3D medical image segmentation method (UNesT), employing a simplified and faster-converging transformer encoder design that achieves local communication among spatially adjacent patch sequences by aggregating them hierarchically. We extensively validate our method on multiple challenging datasets, consisting anatomies of 133 structures in brain, 14 organs in abdomen, 4 hierarchical components in kidney, and inter-connected kidney tumors). We show that UNesT consistently achieves state-of-the-art performance and evaluate its generalizability and data efficiency. Particularly, the model achieves whole brain segmentation task complete ROI with 133 tissue classes in single network, outperforms prior state-of-the-art method SLANT27 ensembled with 27 network tiles, our model performance increases the mean DSC score of the publicly available Colin and CANDI dataset from 0.7264 to 0.7444 and from 0.6968 to 0.7025, respectively.
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从单个放射学图像中学到的功能无法提供有关随着时间的流逝可能发生的病变以及多少变化的信息。从重复图像计算出的时间相关特征可以捕获这些变化,并通过其时间行为来识别恶性病变。但是,纵向医学成像提出了数据获取的稀疏,不规则时间间隔的独特挑战。虽然自我注意事项已被证明是时间序列和自然图像的一种多功能,有效的学习机制,但尚未探索其在稀疏,不规则采样的空​​间特征之间解释时间距离的潜力。在这项工作中,我们通过使用(1)连续时间的矢量嵌入和(2)时间强调自我注意力的权重来提出两种解释时间距离视觉变压器(VIT)。这两种算法是根据合成肺结节的良性与恶性肺癌区分和肺筛查计算机断层扫描研究(NLST)评估的。与标准VIT相比,评估合成结节的时间段VIT的实验表明,在对不规则采样的纵向图像进行分类方面有了基本改进。在从NLST筛选胸部CTS的交叉验证中,我们的方法(分别为0.785和0.786 AUC)显着超过了横截面方法(0.734 AUC)(0.734 AUC),并匹配领先的纵向医学成像算法(0.779 AUC)在良好的良性上的判别性能与恶性分类。这项工作代表了第一个基于自我注意的框架,用于对纵向医学图像进行分类。我们的代码可从https://github.com/tom1193/time-distance-transformer获得。
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尽管深度学习预测模型在歧视不同阶层方面已经成功,但它们通常会遭受跨越包括医疗保健在内的具有挑战性领域的校准不良。此外,长尾分布在深度学习分类问题(包括临床疾病预测)中构成了巨大挑战。最近提出了一些方法来校准计算机视觉中的深入预测,但是没有发现代表模型如何在不同挑战性的环境中起作用。在本文中,我们通过对四个高影响力校准模型的比较研究来弥合从计算机视觉到医学成像的置信度校准。我们的研究是在不同的情况下进行的(自然图像分类和肺癌风险估计),包括在平衡与不平衡训练集以及计算机视觉与医学成像中进行。我们的结果支持关键发现:(1)我们获得了新的结​​论,这些结论未在不同的学习环境中进行研究,例如,结合两个校准模型,这些模型都可以减轻过度启发的预测,从而导致了不足的预测,并且来自计算机视觉模型的更简单的校准模型域往往更容易被医学成像化。 (2)我们强调了一般计算机视觉任务和医学成像预测之间的差距,例如,校准方法是通用计算机视觉任务的理想选择,实际上可能会损坏医学成像预测的校准。 (3)我们还加强了自然图像分类设置的先前结论。我们认为,这项研究的优点可以指导读者选择校准模型,并了解一般计算机视觉和医学成像域之间的差距。
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随机临床试验消除混淆,但施加严格的排除标准,限制招聘到人口的子集。观察数据集更具包容性,但遭受混淆 - 通常在实践中提供对治疗效果的过度乐观估计。因此,我们假设真正的治疗效果在没有治疗效果和观察估计之间的某个地方,或者在其凸壳之间。这种假设允许我们通过使用称为最优凸壳(OCH)的算法同时分析观察和试验数据来推断从更广泛的人群到更广泛的人群的结果。 Och表示根据条件密度的条件期望或凸壳(也称为混合物)的凸壳的治疗效果。该算法首先使用观察数据来学习组件期望或密度,然后使用试验数据来学习线性混合系数,以便近似真实的治疗效果;理论重要地解释了为什么这种线性组合应该保持。 OCH估计治疗效果在术语方面的期望和密度具有最先进的准确性。
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Edge computing is changing the face of many industries and services. Common edge computing models offload computing which is prone to security risks and privacy violation. However, advances in deep learning enabled Internet of Things (IoTs) to take decisions and run cognitive tasks locally. This research introduces a decentralized-control edge model where most computation and decisions are moved to the IoT level. The model aims at decreasing communication to the edge which in return enhances efficiency and decreases latency. The model also avoids data transfer which raises security and privacy risks. To examine the model, we developed SAFEMYRIDES, a scene-aware ridesharing monitoring system where smart phones are detecting violations at the runtime. Current real-time monitoring systems are costly and require continuous network connectivity. The system uses optimized deep learning that run locally on IoTs to detect violations in ridesharing and record violation incidences. The system would enhance safety and security in ridesharing without violating privacy.
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Cognitive Computing (COC) aims to build highly cognitive machines with low computational resources that respond in real-time. However, scholarly literature shows varying research areas and various interpretations of COC. This calls for a cohesive architecture that delineates the nature of COC. We argue that if Herbert Simon considered the design science is the science of artificial, cognitive systems are the products of cognitive science or 'the newest science of the artificial'. Therefore, building a conceptual basis for COC is an essential step into prospective cognitive computing-based systems. This paper proposes an architecture of COC through analyzing the literature on COC using a myriad of statistical analysis methods. Then, we compare the statistical analysis results with previous qualitative analysis results to confirm our findings. The study also comprehensively surveys the recent research on COC to identify the state of the art and connect the advances in varied research disciplines in COC. The study found that there are three underlaying computing paradigms, Von-Neuman, Neuromorphic Engineering and Quantum Computing, that comprehensively complement the structure of cognitive computation. The research discuss possible applications and open research directions under the COC umbrella.
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When testing conditions differ from those represented in training data, so-called out-of-distribution (OOD) inputs can mar the reliability of black-box learned components in the modern robot autonomy stack. Therefore, coping with OOD data is an important challenge on the path towards trustworthy learning-enabled open-world autonomy. In this paper, we aim to demystify the topic of OOD data and its associated challenges in the context of data-driven robotic systems, drawing connections to emerging paradigms in the ML community that study the effect of OOD data on learned models in isolation. We argue that as roboticists, we should reason about the overall system-level competence of a robot as it performs tasks in OOD conditions. We highlight key research questions around this system-level view of OOD problems to guide future research toward safe and reliable learning-enabled autonomy.
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Rigorous guarantees about the performance of predictive algorithms are necessary in order to ensure their responsible use. Previous work has largely focused on bounding the expected loss of a predictor, but this is not sufficient in many risk-sensitive applications where the distribution of errors is important. In this work, we propose a flexible framework to produce a family of bounds on quantiles of the loss distribution incurred by a predictor. Our method takes advantage of the order statistics of the observed loss values rather than relying on the sample mean alone. We show that a quantile is an informative way of quantifying predictive performance, and that our framework applies to a variety of quantile-based metrics, each targeting important subsets of the data distribution. We analyze the theoretical properties of our proposed method and demonstrate its ability to rigorously control loss quantiles on several real-world datasets.
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Graph Neural Networks (GNNs) have shown great potential in the field of graph representation learning. Standard GNNs define a local message-passing mechanism which propagates information over the whole graph domain by stacking multiple layers. This paradigm suffers from two major limitations, over-squashing and poor long-range dependencies, that can be solved using global attention but significantly increases the computational cost to quadratic complexity. In this work, we propose an alternative approach to overcome these structural limitations by leveraging the ViT/MLP-Mixer architectures introduced in computer vision. We introduce a new class of GNNs, called Graph MLP-Mixer, that holds three key properties. First, they capture long-range dependency and mitigate the issue of over-squashing as demonstrated on the Long Range Graph Benchmark (LRGB) and the TreeNeighbourMatch datasets. Second, they offer better speed and memory efficiency with a complexity linear to the number of nodes and edges, surpassing the related Graph Transformer and expressive GNN models. Third, they show high expressivity in terms of graph isomorphism as they can distinguish at least 3-WL non-isomorphic graphs. We test our architecture on 4 simulated datasets and 7 real-world benchmarks, and show highly competitive results on all of them.
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The recent emergence of new algorithms for permuting models into functionally equivalent regions of the solution space has shed some light on the complexity of error surfaces, and some promising properties like mode connectivity. However, finding the right permutation is challenging, and current optimization techniques are not differentiable, which makes it difficult to integrate into a gradient-based optimization, and often leads to sub-optimal solutions. In this paper, we propose a Sinkhorn re-basin network with the ability to obtain the transportation plan that better suits a given objective. Unlike the current state-of-art, our method is differentiable and, therefore, easy to adapt to any task within the deep learning domain. Furthermore, we show the advantage of our re-basin method by proposing a new cost function that allows performing incremental learning by exploiting the linear mode connectivity property. The benefit of our method is compared against similar approaches from the literature, under several conditions for both optimal transport finding and linear mode connectivity. The effectiveness of our continual learning method based on re-basin is also shown for several common benchmark datasets, providing experimental results that are competitive with state-of-art results from the literature.
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