多模式信息在医疗任务中经常可用。通过结合来自多个来源的信息，临床医生可以做出更准确的判断。近年来，在临床实践中使用了多种成像技术进行视网膜分析：2D眼底照片，3D光学相干断层扫描（OCT）和3D OCT血管造影等。我们的论文研究了基于深度学习的三种多模式信息融合策略，以求解视网膜视网膜分析任务：早期融合，中间融合和分层融合。常用的早期和中间融合很简单，但不能完全利用模式之间的互补信息。我们开发了一种分层融合方法，该方法着重于将网络多个维度的特征组合在一起，并探索模式之间的相关性。这些方法分别用于使用公共伽马数据集（Felcus Photophs和OCT）以及Plexelite 9000（Carl Zeis Meditec Inc.）的私人数据集，将这些方法应用于青光眼和糖尿病性视网膜病变分类。我们的分层融合方法在病例中表现最好，并为更好的临床诊断铺平了道路。
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纵向成像能够捕获静态解剖结构和疾病进展的动态变化，向早期和更好的患者特异性病理学管理。但是，检测糖尿病性视网膜病（DR）的常规方法很少利用纵向信息来改善DR分析。在这项工作中，我们调查了利用纵向诊断目的的纵向性质利用自我监督学习的好处。我们比较了不同的纵向自学学习（LSSL）方法，以模拟从纵向视网膜颜色眼底照片（CFP）进行疾病进展，以便使用一对连续考试来检测早期的DR严重性变化。实验是在有或没有那些经过训练的编码器（LSSL）的纵向DR筛选数据集上进行的，该数据集充当纵向借口任务。结果对于基线（从头开始训练）的AUC为0.875，AUC为0.96（95％CI：0.9593-0.9655 DELONG测试），使用p值<2.2e-16，在早期融合上使用简单的重置式结构，使用冷冻的LSSL重量，这表明LSSL潜在空间可以编码DR进程的动态。
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干眼症（DED）的患病率为5％至50％，是眼科医生咨询的主要原因之一。 DED的诊断和定量通常依赖于通过缝隙灯 - 检查的眼表面分析。但是，评估是主观的且不可再生的。为了改善诊断，我们建议1）使用考试期间获得的视频记录在3D中跟踪眼表面，以及2）使用注册框架对严重程度进行评分。我们的注册方法使用无监督的图像到深度学习。这些方法从灯光和阴影中学习深度，并根据深度图估算姿势。但是，DED考试经历尚未解决的挑战，包括移动的光源，透明的眼组织等。为了克服这些挑战，我们为这些挑战并估算了自我动机，我们实施了联合CNN体系结构，具有多种损失，包括先前的已知信息，即通过眼睛的形状，即通过语义分割以及球体拟合。所达到的跟踪误差优于最先进的，其平均欧几里得距离低至我们的测试集中图像宽度的0.48％。该注册将DED严重性分类提高了0.20 AUC差异。拟议的方法是第一个通过单眼视频监督来解决DED诊断的方法
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For long-term simultaneous planning, localization and mapping (SPLAM), a robot should be able to continuously update its map according to the dynamic changes of the environment and the new areas explored. With limited onboard computation capabilities, a robot should also be able to limit the size of the map used for online localization and mapping. This paper addresses these challenges using a memory management mechanism, which identifies locations that should remain in a Working Memory (WM) for online processing from locations that should be transferred to a Long-Term Memory (LTM). When revisiting previously mapped areas that are in LTM, the mechanism can retrieve these locations and place them back in WM for online SPLAM. The approach is tested on a robot equipped with a short-range laser rangefinder and a RGB-D camera, patrolling autonomously 10.5 km in an indoor environment over 11 sessions while having encountered 139 people.
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Vision transformers have emerged as powerful tools for many computer vision tasks. It has been shown that their features and class tokens can be used for salient object segmentation. However, the properties of segmentation transformers remain largely unstudied. In this work we conduct an in-depth study of the spatial attentions of different backbone layers of semantic segmentation transformers and uncover interesting properties. The spatial attentions of a patch intersecting with an object tend to concentrate within the object, whereas the attentions of larger, more uniform image areas rather follow a diffusive behavior. In other words, vision transformers trained to segment a fixed set of object classes generalize to objects well beyond this set. We exploit this by extracting heatmaps that can be used to segment unknown objects within diverse backgrounds, such as obstacles in traffic scenes. Our method is training-free and its computational overhead negligible. We use off-the-shelf transformers trained for street-scene segmentation to process other scene types.
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Unpaired exemplar-based image-to-image (UEI2I) translation aims to translate a source image to a target image domain with the style of a target image exemplar, without ground-truth input-translation pairs. Existing UEI2I methods represent style using either a global, image-level feature vector, or one vector per object instance/class but requiring knowledge of the scene semantics. Here, by contrast, we propose to represent style as a dense feature map, allowing for a finer-grained transfer to the source image without requiring any external semantic information. We then rely on perceptual and adversarial losses to disentangle our dense style and content representations, and exploit unsupervised cross-domain semantic correspondences to warp the exemplar style to the source content. We demonstrate the effectiveness of our method on two datasets using standard metrics together with a new localized style metric measuring style similarity in a class-wise manner. Our results evidence that the translations produced by our approach are more diverse and closer to the exemplars than those of the state-of-the-art methods while nonetheless preserving the source content.
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The optimal layout of a complex system such as aerospace vehicles consists in placing a given number of components in a container in order to minimize one or several objectives under some geometrical or functional constraints. This paper presents an extended formulation of this problem as a variable-size design space (VSDS) problem to take into account a large number of architectural choices and components allocation during the design process. As a representative example of such systems, considering the layout of a satellite module, the VSDS aspect translates the fact that the optimizer has to choose between several subdivisions of the components. For instance, one large tank of fuel might be placed as well as two smaller tanks or three even smaller tanks for the same amount of fuel. In order to tackle this NP-hard problem, a genetic algorithm enhanced by an adapted hidden-variables mechanism is proposed. This latter is illustrated on a toy case and an aerospace application case representative to real world complexity to illustrate the performance of the proposed algorithms. The results obtained using the proposed mechanism are reported and analyzed.
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Automatic differentiation (AD) is a technique for computing the derivative of a function represented by a program. This technique is considered as the de-facto standard for computing the differentiation in many machine learning and optimisation software tools. Despite the practicality of this technique, the performance of the differentiated programs, especially for functional languages and in the presence of vectors, is suboptimal. We present an AD system for a higher-order functional array-processing language. The core functional language underlying this system simultaneously supports both source-to-source forward-mode AD and global optimisations such as loop transformations. In combination, gradient computation with forward-mode AD can be as efficient as reverse mode, and the Jacobian matrices required for numerical algorithms such as Gauss-Newton and Levenberg-Marquardt can be efficiently computed.
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With the rise of task-specific pre-training objectives, abstractive summarization models like PEGASUS offer appealing zero-shot performance on downstream summarization tasks. However, the performance of such unsupervised models still lags significantly behind their supervised counterparts. Similarly to the supervised setup, we notice a very high variance in quality among summary candidates from these models whereas only one candidate is kept as the summary output. In this paper, we propose to re-rank summary candidates in an unsupervised manner, aiming to close the performance gap between unsupervised and supervised models. Our approach improves the pre-trained unsupervised PEGASUS by 4.37% to 7.27% relative mean ROUGE across four widely-adopted summarization benchmarks, and achieves relative gains of 7.51% (up to 23.73%) averaged over 30 transfer setups.
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Cutting planes are a crucial component of state-of-the-art mixed-integer programming solvers, with the choice of which subset of cuts to add being vital for solver performance. We propose new distance-based measures to qualify the value of a cut by quantifying the extent to which it separates relevant parts of the relaxed feasible set. For this purpose, we use the analytic centers of the relaxation polytope or of its optimal face, as well as alternative optimal solutions of the linear programming relaxation. We assess the impact of the choice of distance measure on root node performance and throughout the whole branch-and-bound tree, comparing our measures against those prevalent in the literature. Finally, by a multi-output regression, we predict the relative performance of each measure, using static features readily available before the separation process. Our results indicate that analytic center-based methods help to significantly reduce the number of branch-and-bound nodes needed to explore the search space and that our multiregression approach can further improve on any individual method.
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