Accurate airway extraction from computed tomography (CT) images is a critical step for planning navigation bronchoscopy and quantitative assessment of airway-related chronic obstructive pulmonary disease (COPD). The existing methods are challenging to sufficiently segment the airway, especially the high-generation airway, with the constraint of the limited label and cannot meet the clinical use in COPD. We propose a novel two-stage 3D contextual transformer-based U-Net for airway segmentation using CT images. The method consists of two stages, performing initial and refined airway segmentation. The two-stage model shares the same subnetwork with different airway masks as input. Contextual transformer block is performed both in the encoder and decoder path of the subnetwork to finish high-quality airway segmentation effectively. In the first stage, the total airway mask and CT images are provided to the subnetwork, and the intrapulmonary airway mask and corresponding CT scans to the subnetwork in the second stage. Then the predictions of the two-stage method are merged as the final prediction. Extensive experiments were performed on in-house and multiple public datasets. Quantitative and qualitative analysis demonstrate that our proposed method extracted much more branches and lengths of the tree while accomplishing state-of-the-art airway segmentation performance. The code is available at https://github.com/zhaozsq/airway_segmentation.

In this paper, we present a pure-Python open-source library, called PyPop7, for black-box optimization (BBO). It provides a unified and modular interface for more than 60 versions and variants of different black-box optimization algorithms, particularly population-based optimizers, which can be classified into 12 popular families: Evolution Strategies (ES), Natural Evolution Strategies (NES), Estimation of Distribution Algorithms (EDA), Cross-Entropy Method (CEM), Differential Evolution (DE), Particle Swarm Optimizer (PSO), Cooperative Coevolution (CC), Simulated Annealing (SA), Genetic Algorithms (GA), Evolutionary Programming (EP), Pattern Search (PS), and Random Search (RS). It also provides many examples, interesting tutorials, and full-fledged API documentations. Through this new library, we expect to provide a well-designed platform for benchmarking of optimizers and promote their real-world applications, especially for large-scale BBO. Its source code and documentations are available at https://github.com/Evolutionary-Intelligence/pypop and https://pypop.readthedocs.io/en/latest, respectively.

Deep transfer learning has been widely used for knowledge transmission in recent years. The standard approach of pre-training and subsequently fine-tuning, or linear probing, has shown itself to be effective in many down-stream tasks. Therefore, a challenging and ongoing question arises: how to quantify cross-task transferability that is compatible with transferred results while keeping self-consistency? Existing transferability metrics are estimated on the particular model by conversing source and target tasks. They must be recalculated with all existing source tasks whenever a novel unknown target task is encountered, which is extremely computationally expensive. In this work, we highlight what properties should be satisfied and evaluate existing metrics in light of these characteristics. Building upon this, we propose Principal Gradient Expectation (PGE), a simple yet effective method for assessing transferability across tasks. Specifically, we use a restart scheme to calculate every batch gradient over each weight unit more than once, and then we take the average of all the gradients to get the expectation. Thus, the transferability between the source and target task is estimated by computing the distance of normalized principal gradients. Extensive experiments show that the proposed transferability metric is more stable, reliable and efficient than SOTA methods.

Image super-resolution is a common task on mobile and IoT devices, where one often needs to upscale and enhance low-resolution images and video frames. While numerous solutions have been proposed for this problem in the past, they are usually not compatible with low-power mobile NPUs having many computational and memory constraints. In this Mobile AI challenge, we address this problem and propose the participants to design an efficient quantized image super-resolution solution that can demonstrate a real-time performance on mobile NPUs. The participants were provided with the DIV2K dataset and trained INT8 models to do a high-quality 3X image upscaling. The runtime of all models was evaluated on the Synaptics VS680 Smart Home board with a dedicated edge NPU capable of accelerating quantized neural networks. All proposed solutions are fully compatible with the above NPU, demonstrating an up to 60 FPS rate when reconstructing Full HD resolution images. A detailed description of all models developed in the challenge is provided in this paper.

With the advanced request to employ a team of robots to perform a task collaboratively, the research community has become increasingly interested in collaborative simultaneous localization and mapping. Unfortunately, existing datasets are limited in the scale and variation of the collaborative trajectories, even though generalization between inter-trajectories among different agents is crucial to the overall viability of collaborative tasks. To help align the research community's contributions with realistic multiagent ordinated SLAM problems, we propose S3E, a large-scale multimodal dataset captured by a fleet of unmanned ground vehicles along four designed collaborative trajectory paradigms. S3E consists of 7 outdoor and 5 indoor sequences that each exceed 200 seconds, consisting of well temporal synchronized and spatial calibrated high-frequency IMU, high-quality stereo camera, and 360 degree LiDAR data. Crucially, our effort exceeds previous attempts regarding dataset size, scene variability, and complexity. It has 4x as much average recording time as the pioneering EuRoC dataset. We also provide careful dataset analysis as well as baselines for collaborative SLAM and single counterparts. Data and more up-to-date details are found at https://github.com/PengYu-Team/S3E.

Deep learning (DL) methods have been widely applied to anomaly-based network intrusion detection system (NIDS) to detect malicious traffic. To expand the usage scenarios of DL-based methods, the federated learning (FL) framework allows multiple users to train a global model on the basis of respecting individual data privacy. However, it has not yet been systematically evaluated how robust FL-based NIDSs are against existing privacy attacks under existing defenses. To address this issue, we propose two privacy evaluation metrics designed for FL-based NIDSs, including (1) privacy score that evaluates the similarity between the original and recovered traffic features using reconstruction attacks, and (2) evasion rate against NIDSs using Generative Adversarial Network-based adversarial attack with the reconstructed benign traffic. We conduct experiments to show that existing defenses provide little protection that the corresponding adversarial traffic can even evade the SOTA NIDS Kitsune. To defend against such attacks and build a more robust FL-based NIDS, we further propose FedDef, a novel optimization-based input perturbation defense strategy with theoretical guarantee. It achieves both high utility by minimizing the gradient distance and strong privacy protection by maximizing the input distance. We experimentally evaluate four existing defenses on four datasets and show that our defense outperforms all the baselines in terms of privacy protection with up to 7 times higher privacy score, while maintaining model accuracy loss within 3% under optimal parameter combination.

在这项工作中，我们重新审视了弱到较强的一致性框架，该框架由半监视分类的FixMatch推广，在该分类中，对弱扰动的图像的预测可作为其强烈扰动版本的监督。有趣的是，我们观察到，这种简单的管道已经转移到我们的细分方案时已经在最近的高级工作中取得了竞争成果。它的成功在很大程度上依赖于强大数据增强的手动设计，但是，这可能是有限的，并且不足以探索更广泛的扰动空间。在此激励的情况下，我们提出了一个辅助特征扰动流作为补充，从而导致了扩大的扰动空间。另一方面，为了充分探测原始的图像级增强，我们提出了一种双流扰动技术，从而使两个强大的观点能够同时受到共同的弱视图的指导。因此，我们整体统一的双流扰动方法（Unipatch）在Pascal，CityScapes和Coco基准的所有评估方案中都显着超过所有现有方法。我们还证明了我们方法在遥感解释和医学图像分析中的优越性。代码可从https://github.com/liheyoung/unimatch获得。

单元实例分割是一项旨在针对图像中每个单元格的联合检测和分割的新任务。最近，在此任务中应用了许多实例细分方法。尽管取得了巨大的成功，但仍然存在两个主要弱点，这是由于定位细胞中心点的不确定性而引起的。首先，可以很容易地将密集的填充细胞识别到一个细胞中。其次，细胞的细胞很容易被识别为两个细胞。为了克服这两个弱点，我们提出了一个基于多控制回归指南的新细胞实例分割网络。借助多功能回归指导，该网络具有不同视图中每个单元格的能力。具体而言，我们首先提出了一种高斯指导注意机制，以使用高斯标签来指导网络的注意力。然后，我们提出了一个点回归模块，以帮助细胞中心的回归。最后，我们利用上述两个模块的输出来进一步指导实例分割。借助多轮回归指导，我们可以充分利用不同区域的特征，尤其是细胞的中心区域。我们在基准数据集，DSB2018，CA2.5和SCIS上进行了广泛的实验。令人鼓舞的结果表明，我们的网络实现了SOTA（最先进的）性能。在DSB2018和CA2.5上，我们的网络超过1.2％（AP50）。尤其是在SCIS数据集上，我们的网络的性能较大（AP50高3.0％）。可视化和分析进一步证明了我们提出的方法是可以解释的。

基于图形的模型最近在人的重新识别任务中取得了巨大的成功，该任务首先计算了不同人之间的图形拓扑结构（亲和力），然后将信息传递给他们的信息以实现更强的功能。但是，我们在可见的红外人员重新识别任务（VI-REID）中发现了现有的基于图的方法，因为有两个问题：1）火车测试模式平衡差距，这是VI-REID任务的属性。两个模式数据的数量在训练阶段平衡，但推理极为不平衡，导致基于图的VI-REID方法的概括较低。 2）由图形模块的端到端学习方式引起的亚最佳拓扑结构。我们分析训练有素的输入特征会削弱图形拓扑的学习，从而使其在推理过程中不够概括。在本文中，我们提出了一种反事实干预特征转移（CIFT）方法来解决这些问题。具体而言，均匀和异质的特征转移（H2FT）旨在通过两种独立的设计的图形模块和不平衡的场景模拟来减少火车测试模态差距。此外，提出了反事实关系干预（CRI）来利用反事实干预和因果效应工具来突出拓扑结构在整个训练过程中的作用，这使图形拓扑结构更加可靠。对标准VI-REID基准测试的广泛实验表明，CIFT在各种设置下都优于最新方法。

现代有效的卷积神经网络（CNN）始终使用可分开的卷积（DSC）和神经体系结构搜索（NAS）来减少参数数量和计算复杂性。但是网络的一些固有特征被忽略了。受到可视化功能地图和n $ \ times $ n（n $> $ 1）卷积内核的启发，本文介绍了几种准则，以进一步提高参数效率和推理速度。基于这些准则，我们的参数有效的CNN体​​系结构称为\ textit {vgnetg}，比以前的网络更高的准确性和延迟较低，降低了约30％$ \厚度$ 50％的参数。我们的VGNETG-1.0MP在ImageNet分类数据集上具有0.99万参数的67.7％TOP-1准确性和69.2％的TOP-1精度，而参数为114m。此外，我们证明边缘检测器可以通过用固定的边缘检测核代替N $ \ times $ n内核来代替可学习的深度卷积层来混合特征。我们的VGNETF-1.5MP存档64.4％（ - 3.2％）的TOP-1准确性和66.2％（-1.4％）的TOP-1准确性，具有额外的高斯内核。