Brain extraction and registration are important preprocessing steps in neuroimaging data analysis, where the goal is to extract the brain regions from MRI scans (i.e., extraction step) and align them with a target brain image (i.e., registration step). Conventional research mainly focuses on developing methods for the extraction and registration tasks separately under supervised settings. The performance of these methods highly depends on the amount of training samples and visual inspections performed by experts for error correction. However, in many medical studies, collecting voxel-level labels and conducting manual quality control in high-dimensional neuroimages (e.g., 3D MRI) are very expensive and time-consuming. Moreover, brain extraction and registration are highly related tasks in neuroimaging data and should be solved collectively. In this paper, we study the problem of unsupervised collective extraction and registration in neuroimaging data. We propose a unified end-to-end framework, called ERNet (Extraction-Registration Network), to jointly optimize the extraction and registration tasks, allowing feedback between them. Specifically, we use a pair of multi-stage extraction and registration modules to learn the extraction mask and transformation, where the extraction network improves the extraction accuracy incrementally and the registration network successively warps the extracted image until it is well-aligned with the target image. Experiment results on real-world datasets show that our proposed method can effectively improve the performance on extraction and registration tasks in neuroimaging data. Our code and data can be found at https://github.com/ERNetERNet/ERNet
translated by 谷歌翻译
Deformable image registration, i.e., the task of aligning multiple images into one coordinate system by non-linear transformation, serves as an essential preprocessing step for neuroimaging data. Recent research on deformable image registration is mainly focused on improving the registration accuracy using multi-stage alignment methods, where the source image is repeatedly deformed in stages by a same neural network until it is well-aligned with the target image. Conventional methods for multi-stage registration can often blur the source image as the pixel/voxel values are repeatedly interpolated from the image generated by the previous stage. However, maintaining image quality such as sharpness during image registration is crucial to medical data analysis. In this paper, we study the problem of anti-blur deformable image registration and propose a novel solution, called Anti-Blur Network (ABN), for multi-stage image registration. Specifically, we use a pair of short-term registration and long-term memory networks to learn the nonlinear deformations at each stage, where the short-term registration network learns how to improve the registration accuracy incrementally and the long-term memory network combines all the previous deformations to allow an interpolation to perform on the raw image directly and preserve image sharpness. Extensive experiments on both natural and medical image datasets demonstrated that ABN can accurately register images while preserving their sharpness. Our code and data can be found at https://github.com/anonymous3214/ABN
translated by 谷歌翻译
Privacy in AI remains a topic that draws attention from researchers and the general public in recent years. As one way to implement privacy-preserving AI, differentially private learning is a framework that enables AI models to use differential privacy (DP). To achieve DP in the learning process, existing algorithms typically limit the magnitude of gradients with a constant clipping, which requires carefully tuned due to its significant impact on model performance. As a solution to this issue, latest works NSGD and Auto-S innovatively propose to use normalization instead of clipping to avoid hyperparameter tuning. However, normalization-based approaches like NSGD and Auto-S rely on a monotonic weight function, which imposes excessive weight on small gradient samples and introduces extra deviation to the update. In this paper, we propose a Differentially Private Per-Sample Adaptive Clipping (DP-PSAC) algorithm based on a non-monotonic adaptive weight function, which guarantees privacy without the typical hyperparameter tuning process of using a constant clipping while significantly reducing the deviation between the update and true batch-averaged gradient. We provide a rigorous theoretical convergence analysis and show that with convergence rate at the same order, the proposed algorithm achieves a lower non-vanishing bound, which is maintained over training iterations, compared with NSGD/Auto-S. In addition, through extensive experimental evaluation, we show that DP-PSAC outperforms or matches the state-of-the-art methods on multiple main-stream vision and language tasks.
translated by 谷歌翻译
跟踪位置和方向独立提供了更敏捷的动作,以实现过度射击的多旋翼无人机(UAV),同时引入了不希望的倒入效果;推力发电机产生的倾斜流可能会因接近性而抵消其他流动,从而极大地威胁了平台的稳定性。建模空气动力气流的复杂性挑战了适当补偿这种副作用的算法。利用无人机分配的输入冗余,我们通过新的控制分配框架来解决此问题,该框架考虑了倾斜效果,并探索了整个分配空间以获得最佳解决方案。该最佳解决方案避免了倾斜效果,同时在硬件约束中提供了高推力效率。据我们所知,我们的是第一个调查对过度驱动无人机的倾斜影响的正式推导。我们在模拟和实验中验证了不同硬件配置的框架。
translated by 谷歌翻译
由于字体,大小,颜色和方向的各种文本变化,任意形状的场景文本检测是一项具有挑战性的任务。大多数现有基于回归的方法求助于回归文本区域的口罩或轮廓点以建模文本实例。但是,回归完整的口罩需要高训练的复杂性,并且轮廓点不足以捕获高度弯曲的文本的细节。为了解决上述限制,我们提出了一个名为TextDCT的新颖的轻巧锚文本检测框架,该框架采用离散的余弦变换(DCT)将文本掩码编码为紧凑型向量。此外,考虑到金字塔层中训练样本不平衡的数量,我们仅采用单层头来进行自上而下的预测。为了建模单层头部的多尺度文本,我们通过将缩水文本区域视为正样本,并通过融合来介绍一个新颖的积极抽样策略,并通过融合来设计特征意识模块(FAM),以实现空间意识和规模的意识丰富的上下文信息并关注更重要的功能。此外,我们提出了一种分割的非量最大抑制(S-NMS)方法,该方法可以过滤低质量的掩模回归。在四个具有挑战性的数据集上进行了广泛的实验,这表明我们的TextDCT在准确性和效率上都获得了竞争性能。具体而言,TextDCT分别以每秒17.2帧(FPS)和F-measure的F-MEASIE达到85.1,而CTW1500和Total-Text数据集的F-Measure 84.9分别为15.1 fps。
translated by 谷歌翻译
无监督的交叉模式医学图像适应旨在减轻不同成像方式之间的严重域间隙,而无需使用目标域标签。该活动的关键依赖于对齐源和目标域的分布。一种常见的尝试是强制两个域之间的全局对齐,但是,这忽略了致命的局部不平衡域间隙问题,即,一些具有较大域间隙的局部特征很难转移。最近,某些方法进行一致性,重点是地方区域,以提高模型学习的效率。尽管此操作可能会导致上下文中关键信息的缺陷。为了应对这一限制,我们提出了一种新的策略,以减轻医学图像的特征,即全球本地联盟的一致性,以减轻域间隙不平衡。具体而言,功能 - 触发样式转移模块首先合成类似目标的源包含图像,以减少全局域间隙。然后,集成了本地功能掩码,以通过优先考虑具有较大域间隙的判别特征来减少本地特征的“间隙”。全球和局部对齐的这种组合可以精确地将关键区域定位在分割目标中,同时保持整体语义一致性。我们进行了一系列具有两个跨模式适应任务的实验,i,e。心脏子结构和腹部多器官分割。实验结果表明,我们的方法在这两个任务中都达到了最新的性能。
translated by 谷歌翻译
我们设计了一个合作规划框架,为束缚机器人Duo产生最佳轨迹,该轨迹是用柔性网聚集在大面积中蔓延的散射物体。具体地,所提出的规划框架首先为每个机器人生产一组密集的航点,用作优化的初始化。接下来,我们制定迭代优化方案,以产生平滑和无碰撞的轨迹,同时确保机器人DUO内的合作,以有效地收集物体并正确避免障碍物。我们使用模型参考自适应控制器(MRAC)验证模拟中的生成轨迹,并在物理机器人中实现它们,以处理携带有效载荷的未知动态。在一系列研究中,我们发现:(i)U形成本函数在规划合作机器人DUO方面是有效的,并且(ii)任务效率并不总是与系绳网的长度成比例。鉴于环境配置,我们的框架可以衡量最佳净长度。为了我们的最佳知识,我们的最初是第一个为系列机器人二人提供此类估算。
translated by 谷歌翻译
域适应(DA)最近在医学影像社区提出了强烈的兴趣。虽然已经提出了大量DA技术进行了用于图像分割,但大多数这些技术已经在私有数据集或小公共可用数据集上验证。此外,这些数据集主要解决了单级问题。为了解决这些限制,与第24届医学图像计算和计算机辅助干预(Miccai 2021)结合第24届国际会议组织交叉模态域适应(Crossmoda)挑战。 Crossmoda是无监督跨型号DA的第一个大型和多级基准。挑战的目标是分割参与前庭施瓦新瘤(VS)的后续和治疗规划的两个关键脑结构:VS和Cochleas。目前,使用对比度增强的T1(CET1)MRI进行VS患者的诊断和监测。然而,使用诸如高分辨率T2(HRT2)MRI的非对比度序列越来越感兴趣。因此,我们创建了一个无人监督的跨模型分段基准。训练集提供注释CET1(n = 105)和未配对的非注释的HRT2(n = 105)。目的是在测试集中提供的HRT2上自动对HRT2进行单侧VS和双侧耳蜗分割(n = 137)。共有16支球队提交了评估阶段的算法。顶级履行团队达成的表现水平非常高(最佳中位数骰子 - vs:88.4%; Cochleas:85.7%)并接近完全监督(中位数骰子 - vs:92.5%;耳蜗:87.7%)。所有顶级执行方法都使用图像到图像转换方法将源域图像转换为伪目标域图像。然后使用这些生成的图像和为源图像提供的手动注释进行培训分割网络。
translated by 谷歌翻译
生成的型号推理需要机器生成描述日常情景的句子,这是几种概念,最近引起了很多关注。然而,现有模型不能表现和人类,因为它们产生的句子通常是难以置疑和语法的不正确。在本文中,灵感来自人类创造句子的过程,我们提出了一种新颖的知识增强的致辞生成框架,被称为kgr ^ 4,由四个阶段组成:检索,回顾,精炼,重新思考。在此框架下,我们首先执行检索以搜索从外部语料库作为原型的相关句子。然后,我们训练发电机编辑或复制这些原型以生成候选句子,其中基于AutoEncoder的炼油器将修复候选句子。最后,我们从具有不同超参数的生成器产生的候选句子中选择输出句子。对蒙古基准测试的实验结果和深入分析强烈展示了我们框架的有效性。特别是,KGR ^ 4获得官方排行榜中的33.56个香料点,优于前面报告的最佳结果2.49香料点,实现最先进的性能。
translated by 谷歌翻译
Knowledge graph embedding (KGE), which maps entities and relations in a knowledge graph into continuous vector spaces, has achieved great success in predicting missing links in knowledge graphs. However, knowledge graphs often contain incomplete triples that are difficult to inductively infer by KGEs. To address this challenge, we resort to analogical inference and propose a novel and general self-supervised framework AnKGE to enhance KGE models with analogical inference capability. We propose an analogical object retriever that retrieves appropriate analogical objects from entity-level, relation-level, and triple-level. And in AnKGE, we train an analogy function for each level of analogical inference with the original element embedding from a well-trained KGE model as input, which outputs the analogical object embedding. In order to combine inductive inference capability from the original KGE model and analogical inference capability enhanced by AnKGE, we interpolate the analogy score with the base model score and introduce the adaptive weights in the score function for prediction. Through extensive experiments on FB15k-237 and WN18RR datasets, we show that AnKGE achieves competitive results on link prediction task and well performs analogical inference.
translated by 谷歌翻译