The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.
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许多连续的决策问题是使用使用其他一些策略收集的历史数据,需要使用历史数据的高赌注并要求新策略(OPE)。提供无偏估计的最常见的OPE技术之一是基于轨迹的重要性采样(是)。但是,由于轨迹的高方差是估计,最近通过了基于国家行动探索分布(SIS)的重要性采样方法。不幸的是,虽然SIS经常为长视野提供较低的方差估计,但估算状态行动分配比可能是具有挑战性的并且导致偏差估计。在本文中,我们对该偏差差异进行了新的视角,并显示了存在终点是SIS的估计频谱的存在。此外,我们还建立了这些估算器的双重强大和加权版本的频谱。我们提供了经验证据,即该频谱中的估计值可用于在IS和SIS的偏差和方差之间进行折衷,并且可以实现比两者和SIS更低的平均平方误差。
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Deep learning classifiers provide the most accurate means of automatically diagnosing diabetic retinopathy (DR) based on optical coherence tomography (OCT) and its angiography (OCTA). The power of these models is attributable in part to the inclusion of hidden layers that provide the complexity required to achieve a desired task. However, hidden layers also render algorithm outputs difficult to interpret. Here we introduce a novel biomarker activation map (BAM) framework based on generative adversarial learning that allows clinicians to verify and understand classifiers decision-making. A data set including 456 macular scans were graded as non-referable or referable DR based on current clinical standards. A DR classifier that was used to evaluate our BAM was first trained based on this data set. The BAM generation framework was designed by combing two U-shaped generators to provide meaningful interpretability to this classifier. The main generator was trained to take referable scans as input and produce an output that would be classified by the classifier as non-referable. The BAM is then constructed as the difference image between the output and input of the main generator. To ensure that the BAM only highlights classifier-utilized biomarkers an assistant generator was trained to do the opposite, producing scans that would be classified as referable by the classifier from non-referable scans. The generated BAMs highlighted known pathologic features including nonperfusion area and retinal fluid. A fully interpretable classifier based on these highlights could help clinicians better utilize and verify automated DR diagnosis.
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Previous work has shown that a neural network with the rectified linear unit (ReLU) activation function leads to a convex polyhedral decomposition of the input space. These decompositions can be represented by a dual graph with vertices corresponding to polyhedra and edges corresponding to polyhedra sharing a facet, which is a subgraph of a Hamming graph. This paper illustrates how one can utilize the dual graph to detect and analyze adversarial attacks in the context of digital images. When an image passes through a network containing ReLU nodes, the firing or non-firing at a node can be encoded as a bit ($1$ for ReLU activation, $0$ for ReLU non-activation). The sequence of all bit activations identifies the image with a bit vector, which identifies it with a polyhedron in the decomposition and, in turn, identifies it with a vertex in the dual graph. We identify ReLU bits that are discriminators between non-adversarial and adversarial images and examine how well collections of these discriminators can ensemble vote to build an adversarial image detector. Specifically, we examine the similarities and differences of ReLU bit vectors for adversarial images, and their non-adversarial counterparts, using a pre-trained ResNet-50 architecture. While this paper focuses on adversarial digital images, ResNet-50 architecture, and the ReLU activation function, our methods extend to other network architectures, activation functions, and types of datasets.
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ICECUBE是一种用于检测1 GEV和1 PEV之间大气和天体中微子的光学传感器的立方公斤阵列,该阵列已部署1.45 km至2.45 km的南极的冰盖表面以下1.45 km至2.45 km。来自ICE探测器的事件的分类和重建在ICeCube数据分析中起着核心作用。重建和分类事件是一个挑战,这是由于探测器的几何形状,不均匀的散射和冰中光的吸收,并且低于100 GEV的光,每个事件产生的信号光子数量相对较少。为了应对这一挑战,可以将ICECUBE事件表示为点云图形,并将图形神经网络(GNN)作为分类和重建方法。 GNN能够将中微子事件与宇宙射线背景区分开,对不同的中微子事件类型进行分类,并重建沉积的能量,方向和相互作用顶点。基于仿真,我们提供了1-100 GEV能量范围的比较与当前ICECUBE分析中使用的当前最新最大似然技术,包括已知系统不确定性的影响。对于中微子事件分类,与当前的IceCube方法相比,GNN以固定的假阳性速率(FPR)提高了信号效率的18%。另外,GNN在固定信号效率下将FPR的降低超过8(低于半百分比)。对于能源,方向和相互作用顶点的重建,与当前最大似然技术相比,分辨率平均提高了13%-20%。当在GPU上运行时,GNN能够以几乎是2.7 kHz的中位数ICECUBE触发速率的速率处理ICECUBE事件,这打开了在在线搜索瞬态事件中使用低能量中微子的可能性。
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Hololens(Microsoft Corp.,WA Redmond,WA)是一款头饰,光学透明的增强现实展示,是最近提高医学增强现实研究的主要参与者。在医疗环境中,HoloLens使医生能够立即了解患者信息,直接与他们对临床方案的看法,医学生,可以更好地了解复杂的解剖学或程序,甚至可以通过执行治疗任务。改进,沉浸式指导。在这篇系统的综述中,我们提供了有关医疗领域第一代霍洛伦斯在2016年3月发布到2021年的全面使用的全面概述,一直关注其继任者霍洛伦斯2号。通过系统搜索PubMed和Scopus数据库确定了171个相关出版物。我们分析了这些出版物的预期用例,注册和跟踪的技术方法,数据源,可视化以及验证和评估。我们发现,尽管已经显示出在各种医学场景中使用Hololens的可行性,但在精确,可靠性,可用性,工作流程和感知方面的努力增加了在临床实践中建立AR。
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脑小血管疾病的成像标记提供了有关脑部健康的宝贵信息,但是它们的手动评估既耗时又受到实质性内部和间际变异性的阻碍。自动化评级可能受益于生物医学研究以及临床评估,但是现有算法的诊断可靠性尚不清楚。在这里,我们介绍了\ textIt {血管病变检测和分割}(\ textit {v textit {where valdo?})挑战,该挑战是在国际医学图像计算和计算机辅助干预措施(MICCAI)的卫星事件中运行的挑战(MICCAI) 2021.这一挑战旨在促进大脑小血管疾病的小而稀疏成像标记的自动检测和分割方法的开发,即周围空间扩大(EPVS)(任务1),脑微粒(任务2)和预先塑造的鞋类血管起源(任务3),同时利用弱和嘈杂的标签。总体而言,有12个团队参与了针对一个或多个任务的解决方案的挑战(任务1 -EPVS 4,任务2 -Microbleeds的9个,任务3 -lacunes的6个)。多方数据都用于培训和评估。结果表明,整个团队和跨任务的性能都有很大的差异,对于任务1- EPV和任务2-微型微型且对任务3 -lacunes尚无实际的结果,其结果尤其有望。它还强调了可能阻止个人级别使用的情况的性能不一致,同时仍证明在人群层面上有用。
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细菌感染负责全球高死亡率。感染潜在的抗菌素耐药性,多方面的患者的临床状况会阻碍正确选择抗生素治疗。随机临床试验提供了平均治疗效果估计值,但对于治疗选择的风险分层和优化,即个性化治疗效果(ITE)并不理想。在这里,我们利用了从美国南部学术诊所收集的大规模电子健康记录数据,模仿临床试验,即“目标试验”,并为诊断患有急性细菌的患者开发了死亡率预测和ITE估计的机器学习模型皮肤和皮肤结构感染(ABSSI)是由于金黄色葡萄球菌(MRSA)引起的。 ABSSI-MRSA是一个充满挑战的疾病,治疗选择减少 - 万古霉素是首选的选择,但它具有不可忽略的副作用。首先,我们使用倾向评分匹配来模仿试验并创建随机治疗(万古霉素与其他抗生素)数据集。接下来,我们使用此数据来训练各种机器学习方法(包括增强/Lasso Logistic回归,支持向量机和随机森林),并通过引导验证选择接收器特征(AUC)下的面积最佳模型。最后,我们使用这些模型来计算ITE并通过改变治疗的变化来避免死亡。排出外测试表明,SVM和RF是最准确的,AUC分别为81%和78%,但BLR/Lasso不远(76%)。通过使用BLR/Lasso计算反事实,万古霉素增加了死亡的风险,但显示出很大的变化(优势比1.2,95%范围0.4-3.8),对结果概率的贡献是适度的。取而代之的是,RF在ITE中表现出更大的变化,表明更复杂的治疗异质性。
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人工智能的最新趋势是将验证的模型用于语言和视觉任务,这些模型已经实现了非凡的表现,但也令人困惑。因此,以各种方式探索这些模型的能力对该领域至关重要。在本文中,我们探讨了模型的可靠性,在其中我们将可靠的模型定义为一个不仅可以实现强大的预测性能,而且在许多涉及不确定性(例如选择性预测,开放式设置识别)的决策任务上,在许多决策任务上表现出色,而且表现良好。强大的概括(例如,准确性和适当的评分规则,例如在分布数据集中和分发数据集上的对数可能性)和适应性(例如,主动学习,几乎没有射击不确定性)。我们设计了40个数据集的10种任务类型,以评估视觉和语言域上可靠性的不同方面。为了提高可靠性,我们分别开发了VIT-PLEX和T5-PLEX,分别针对视觉和语言方式扩展了大型模型。 PLEX极大地改善了跨可靠性任务的最先进,并简化了传统协议,因为它可以改善开箱即用的性能,并且不需要设计分数或为每个任务调整模型。我们演示了高达1B参数的模型尺寸的缩放效果,并预处理数据集大小最多4B示例。我们还展示了PLEX在具有挑战性的任务上的功能,包括零射门的开放式识别,主动学习和对话语言理解中的不确定性。
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金属有机框架(MOF)是一类模块化的多孔晶体材料,具有巨大的革命性应用,例如储气,分子分离,化学感应,催化和药物输送。剑桥结构数据库(CSD)报告了10,636个合成的MOF晶体,此外还包含CA。114,373个类似MOF的结构。综合数量(加上可能合成的)MOF结构数量庞大,需要研究人员追求计算技术来筛选和分离MOF候选物。在此演示论文中,我们描述了我们在利用知识图方法方面促进MOF预测,发现和综合方面的努力。我们提出了有关(1)从结构化和非结构化来源构建MOF知识图(MOF-KG)的挑战和案例研究,以及(2)利用MOF-KG来发现新知识或缺失知识。
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