在多机器人应用程序中,对大状态空间的推断通常可以分为较小的重叠子问题,然后可以在状态的“单独”子集上并行解决。为此,开发了因子图分散数据融合(FG-DDF)框架,以分析和利用异质贝叶斯分散融合问题的有条件独立性,其中机器人在不同的本地重叠随机状态上更新和融合PDF。这允许机器人有效地使用较小的概率模型和稀疏消息传递到较大的全局关节状态PDF的相关局部部分,同时考虑了机器人之间的数据依赖性。尽管先前的工作需要限制有关网络连接性和模型线性性的假设,但本文放宽了这些假设,以验证FG-DDF在更一般的环境中的适用性和鲁棒性。我们制定了一个新的异质融合规则,该规则将概括均匀的协方差相交算法,并在通信删除下使用非线性运动/观察模型在多机器人跟踪和本地化方案中测试它。仿真和线性硬件实验表明,实际上,FG-DDF在这些更实用的操作条件下继续提供一致的过滤估计,同时将计算和通信成本降低了95%以上,从而实现了可扩展现实世界中的多项式的设计 - 机器人系统。
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Prostate cancer (PCa) is one of the most prevalent cancers in men and many people around the world die from clinically significant PCa (csPCa). Early diagnosis of csPCa in bi-parametric MRI (bpMRI), which is non-invasive, cost-effective, and more efficient compared to multiparametric MRI (mpMRI), can contribute to precision care for PCa. The rapid rise in artificial intelligence (AI) algorithms are enabling unprecedented improvements in providing decision support systems that can aid in csPCa diagnosis and understanding. However, existing state of the art AI algorithms which are based on deep learning technology are often limited to 2D images that fails to capture inter-slice correlations in 3D volumetric images. The use of 3D convolutional neural networks (CNNs) partly overcomes this limitation, but it does not adapt to the anisotropy of images, resulting in sub-optimal semantic representation and poor generalization. Furthermore, due to the limitation of the amount of labelled data of bpMRI and the difficulty of labelling, existing CNNs are built on relatively small datasets, leading to a poor performance. To address the limitations identified above, we propose a new Zonal-aware Self-supervised Mesh Network (Z-SSMNet) that adaptatively fuses multiple 2D, 2.5D and 3D CNNs to effectively balance representation for sparse inter-slice information and dense intra-slice information in bpMRI. A self-supervised learning (SSL) technique is further introduced to pre-train our network using unlabelled data to learn the generalizable image features. Furthermore, we constrained our network to understand the zonal specific domain knowledge to improve the diagnosis precision of csPCa. Experiments on the PI-CAI Challenge dataset demonstrate our proposed method achieves better performance for csPCa detection and diagnosis in bpMRI.
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The application of natural language processing (NLP) to cancer pathology reports has been focused on detecting cancer cases, largely ignoring precancerous cases. Improving the characterization of precancerous adenomas assists in developing diagnostic tests for early cancer detection and prevention, especially for colorectal cancer (CRC). Here we developed transformer-based deep neural network NLP models to perform the CRC phenotyping, with the goal of extracting precancerous lesion attributes and distinguishing cancer and precancerous cases. We achieved 0.914 macro-F1 scores for classifying patients into negative, non-advanced adenoma, advanced adenoma and CRC. We further improved the performance to 0.923 using an ensemble of classifiers for cancer status classification and lesion size named entity recognition (NER). Our results demonstrated the potential of using NLP to leverage real-world health record data to facilitate the development of diagnostic tests for early cancer prevention.
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Approximation fixpoint theory (AFT) is an abstract and general algebraic framework for studying the semantics of nonmonotonic logics. It provides a unifying study of the semantics of different formalisms for nonmonotonic reasoning, such as logic programming, default logic and autoepistemic logic. In this paper, we extend AFT to dealing with non-deterministic constructs that allow to handle indefinite information, represented e.g. by disjunctive formulas. This is done by generalizing the main constructions and corresponding results of AFT to non-deterministic operators, whose ranges are sets of elements rather than single elements. The applicability and usefulness of this generalization is illustrated in the context of disjunctive logic programming.
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Outcome prediction is crucial for head and neck cancer patients as it can provide prognostic information for early treatment planning. Radiomics methods have been widely used for outcome prediction from medical images. However, these methods are limited by their reliance on intractable manual segmentation of tumor regions. Recently, deep learning methods have been proposed to perform end-to-end outcome prediction so as to remove the reliance on manual segmentation. Unfortunately, without segmentation masks, these methods will take the whole image as input, such that makes them difficult to focus on tumor regions and potentially unable to fully leverage the prognostic information within the tumor regions. In this study, we propose a radiomics-enhanced deep multi-task framework for outcome prediction from PET/CT images, in the context of HEad and neCK TumOR segmentation and outcome prediction challenge (HECKTOR 2022). In our framework, our novelty is to incorporate radiomics as an enhancement to our recently proposed Deep Multi-task Survival model (DeepMTS). The DeepMTS jointly learns to predict the survival risk scores of patients and the segmentation masks of tumor regions. Radiomics features are extracted from the predicted tumor regions and combined with the predicted survival risk scores for final outcome prediction, through which the prognostic information in tumor regions can be further leveraged. Our method achieved a C-index of 0.681 on the testing set, placing the 2nd on the leaderboard with only 0.00068 lower in C-index than the 1st place.
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多模式性荧光脱氧葡萄糖(FDG)正电子发射断层扫描 /计算机断层扫描(PET / CT)已常规用于评估常见癌症,例如肺癌,淋巴瘤和黑色素瘤。这主要归因于以下事实:PET/CT结合了对PET肿瘤检测的高灵敏度和CT的解剖学信息。在PET/CT图像评估中,自动肿瘤分割是重要的一步,近年来,基于深度学习的方法已成为最新方法。不幸的是,现有的方法倾向于过度细分肿瘤区域,并包括正常摄取器官,炎症和其他感染等区域。在这项研究中,我们引入了一个假阳性还原网络以克服这一限制。我们首先引入了一个自制的预训练的全球分割模块,以使用自我监督的预训练的编码器粗糙地描绘候选肿瘤区域。然后,通过局部细化模块去除假阳性来完善候选肿瘤区域。我们对MICCAI 2022自动病变分割的实验在全身FDG-PET/CT(AUTOPET)挑战数据集中表明,我们的方法在初步测试数据中获得了0.9324的骰子得分,并在排行榜上排名第一。我们的方法在最终测试数据的前7位方法中也排名,最终排名将在2022 MICCAI AUTOPET研讨会期间宣布。我们的代码可在以下网址提供:https://github.com/yigepeng/autopet_false_posisity_reduction。
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在过去的十年中,神经网络(NNS)已被广泛用于许多应用程序,包括安全系统,例如自主系统。尽管采用了新兴的采用,但众所周知,NNS容易受到对抗攻击的影响。因此,提供确保此类系统正常工作的保证非常重要。为了解决这些问题,我们介绍了一个修复不安全NNS W.R.T.的框架。安全规范,即利用可满足的模型理论(SMT)求解器。我们的方法能够通过仅修改其重量值的一些重量值来搜索新的,安全的NN表示形式。此外,我们的技术试图最大程度地提高与原始网络在其决策边界方面的相似性。我们进行了广泛的实验,以证明我们提出的框架能够产生安全NNS W.R.T.的能力。对抗性的鲁棒性特性,只有轻度的准确性损失(就相似性而言)。此外,我们将我们的方法与天真的基线进行比较,以证明其有效性。总而言之,我们提供了一种算法以自动修复具有安全性的算法,并建议一些启发式方法以提高其计算性能。当前,通过遵循这种方法,我们能够产生由分段线性relu激活函数组成的小型(即具有多达数百个参数)的小型(即具有多达数百个参数)。然而,我们的框架是可以合成NNS W.R.T.的一般框架。一阶逻辑规范的任何可决定片段。
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鉴于选择算法和/或配置问题,黑框优化(BBO)问题的搜索地面特征(BBO)问题的知识提供了有价值的信息。探索性景观分析(ELA)模型已在识别预定义的人类衍生特征和促进投资组合选择器方面取得成功,以应对这些挑战。与ELA方法不同,当前的研究提议将识别问题转变为图像识别问题,并有可能检测不含概念的机器驱动的景观特征。为此,我们介绍了景观图像的概念,这使我们能够每个基准函数生成图像实例,然后将分类挑战定位于各种函数的广义数据集。我们将其作为有监督的多级图像识别问题来解决,并应用基本的人工神经网络模型来解决它。我们方法的功效在无噪声的BBOB和IOHPRILER基准测试套件上进行了数值验证。这种明显的成功学习是朝着自动化特征提取和局部结构扣除BBO问题的又一步。通过使用这种景观图像的定义,并利用图像识别算法的现有功能,我们预见了像Imagenet一样的功能库的构建,用于训练依靠机器驱动功能的通用检测器。
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可变形图像注册是医学图像分析中的关键步骤,用于在一对固定图像和移动图像之间找到非线性空间转换。基于卷积神经网络(CNN)的深度注册方法已被广泛使用,因为它们可以快速和端到端的方式执行图像注册。但是,这些方法通常对具有较大变形的图像对的性能有限。最近,迭代深度注册方法已被用来减轻这种限制,在这种限制中,转换以粗到精细的方式迭代学习。但是,迭代方法不可避免地会延长注册运行时,并倾向于学习每次迭代的单独图像特征,从而阻碍了功能的利用,以便在以后的迭代时促进注册。在这项研究中,我们提出了一个非详细的粗到十五个注册网络(NICE-NET),用于可变形图像注册。在Nice-Net中,我们提出:(i)单个深度累积学习(SDCL)解码器,可以在网络的单个通过(迭代)中累积地学习粗到5的转换,以及(ii)选择性地 - 传播功能学习(SFL)编码器,可以为整个粗到精细的注册过程学习通用图像功能,并根据需要选择性地传播功能。在3D脑磁共振成像(MRI)的六个公共数据集上进行了广泛的实验表明,我们提出的Nice-NET可以超越最新的迭代深度注册方法,而仅需要与非辅助方法类似的运行时间。
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我们证明了快速混合并表征了langevin算法的固定分布,用于反转随机加权DNN发电机。该结果将手和Voroninski的工作从有效的反转到有效的后部采样。实际上,为了提高表达性,我们建议在预训练的生成模型的潜在空间中进行后验采样。为了实现这一目标,我们在StyleGAN-2的潜在空间中训练基于分数的模型,并使用它来解决反问题。我们的框架,得分引导的中间层优化(SGILO),通过用中间层中的生成性先验代替稀疏正则化来扩展先前的工作。在实验上,我们对先前的最新面临,尤其是在低测量方案中获得了显着改善。
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