超声成像在诊断血管病变中起重要作用。血管壁的准确分割对于预防,诊断和治疗血管疾病很重要。但是,现有方法的血管壁边界的定位不准确。分割误差发生在不连续的血管壁边界和黑暗边界中。为了克服这些问题,我们提出了一个新的边界限制网络(BDNET)。我们使用边界细化模块重新限制血管壁的边界以获得正确的边界位置。我们设计了特征提取模块来提取和融合多尺度特征和不同的接受场功能,以解决黑暗边界和不连续边界的问题。我们使用新的损失函数来优化模型。级别不平衡对模型优化的干扰可阻止获得更细致,更光滑的边界。最后,为了促进临床应用,我们将模型设计为轻量级。实验结果表明,与数据集的现有模型相比,我们的模型可实现最佳的分割结果,并显着降低记忆消耗。
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开放式识别使深度神经网络(DNN)能够识别未知类别的样本,同时在已知类别的样本上保持高分类精度。基于自动编码器(AE)和原型学习的现有方法在处理这项具有挑战性的任务方面具有巨大的潜力。在这项研究中,我们提出了一种新的方法,称为类别特定的语义重建(CSSR),该方法整合了AE和原型学习的力量。具体而言,CSSR用特定于类的AE表示的歧管替代了原型点。与传统的基于原型的方法不同,CSSR在单个AE歧管上的每个已知类模型,并通过AE的重建误差来测量类归属感。特定于类的AE被插入DNN主链的顶部,并重建DNN而不是原始图像所学的语义表示。通过端到端的学习,DNN和AES互相促进,以学习歧视性和代表性信息。在多个数据集上进行的实验结果表明,所提出的方法在封闭式和开放式识别中都达到了出色的性能,并且非常简单且灵活地将其纳入现有框架中。
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作为一种强大的建模方法,分段线性神经网络(PWLNNS)已在各个领域都被证明是成功的,最近在深度学习中。为了应用PWLNN方法,长期以来一直研究了表示和学习。 1977年,规范表示率先通过增量设计学到了浅层PWLNN的作品,但禁止使用大规模数据的应用。 2010年,纠正的线性单元(RELU)提倡在深度学习中PWLNN的患病率。从那以后,PWLNNS已成功地应用于广泛的任务并实现了有利的表现。在本引物中,我们通过将作品分组为浅网络和深层网络来系统地介绍PWLNNS的方法。首先,不同的PWLNN表示模型是由详细示例构建的。使用PWLNNS,提出了学习数据的学习算法的演变,并且基本理论分析遵循深入的理解。然后,将代表性应用与讨论和前景一起引入。
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The score-based query attacks (SQAs) pose practical threats to deep neural networks by crafting adversarial perturbations within dozens of queries, only using the model's output scores. Nonetheless, we note that if the loss trend of the outputs is slightly perturbed, SQAs could be easily misled and thereby become much less effective. Following this idea, we propose a novel defense, namely Adversarial Attack on Attackers (AAA), to confound SQAs towards incorrect attack directions by slightly modifying the output logits. In this way, (1) SQAs are prevented regardless of the model's worst-case robustness; (2) the original model predictions are hardly changed, i.e., no degradation on clean accuracy; (3) the calibration of confidence scores can be improved simultaneously. Extensive experiments are provided to verify the above advantages. For example, by setting $\ell_\infty=8/255$ on CIFAR-10, our proposed AAA helps WideResNet-28 secure 80.59% accuracy under Square attack (2500 queries), while the best prior defense (i.e., adversarial training) only attains 67.44%. Since AAA attacks SQA's general greedy strategy, such advantages of AAA over 8 defenses can be consistently observed on 8 CIFAR-10/ImageNet models under 6 SQAs, using different attack targets, bounds, norms, losses, and strategies. Moreover, AAA calibrates better without hurting the accuracy. Our code is available at https://github.com/Sizhe-Chen/AAA.
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建议绑架自然语言推理任务($ \ alpha $ NLI)以推断出原因与事件之间的最合理的解释。在$ \ Alpha $ NLI任务中,给出了两个观察,并要求最合理的假设从候选人中挑出。现有方法将每个候选假说之间的关系进行分别统一地惩罚推理网络。在本文中,我们认为不必区分正确假设之间的推理能力;同样,在解释观察的原因时,所有错误的假设都会有所贡献。因此,我们建议小组而不是排名假设和设计本文中称为“联合软制焦点”的结构损失。基于观察,假设通常与语义相关,我们设计了一种新颖的互动语言模型,旨在利用竞争假设之间丰富的互动。我们为$ \ alpha $ nli命名这个新型号:具有结构丢失(IMSL)的交互式模型。实验结果表明,我们的IMSL已经在罗伯塔大型预磨削模型上实现了最高性能,ACC和AUC结果分别增加了约1 \%和5 \%。
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深度神经网络(DNN)被视为易受对抗性攻击的影响,而现有的黑匣子攻击需要广泛查询受害者DNN以实现高成功率。对于查询效率,由于它们的梯度相似度(GS),即代理的攻击梯度与受害者的攻击梯度类似,因此使用受害者的代理模型来生成可转移的对抗性示例(AES)。但是,通常忽略了它们对输出的相似性,即预测相似性(PS),以在不查询受害者的情况下通过代理过滤效率低效查询。要共同利用和还优化代理者的GS和PS,我们开发QueryNet,一个可以显着减少查询的统一攻击框架。 Querynet通过多识别代理人创造性地攻击,即通过不同的代理商为一个样本工艺几个AES,并且还使用代理人来决定查询最有前途的AE。之后,受害者的查询反馈累积以优化代理人的参数,还可以优化其架构,增强GS和PS。虽然Querynet无法获得预先接受预先训练的代理人,但根据我们的综合实验,它与可接受的时间内的替代方案相比,它会降低查询。 ImageNet,只允许8位图像查询,无法访问受害者的培训数据。代码可在https://github.com/allenchen1998/querynet上获得。
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Image-based head swapping task aims to stitch a source head to another source body flawlessly. This seldom-studied task faces two major challenges: 1) Preserving the head and body from various sources while generating a seamless transition region. 2) No paired head swapping dataset and benchmark so far. In this paper, we propose an image-based head swapping framework (HS-Diffusion) which consists of a semantic-guided latent diffusion model (SG-LDM) and a semantic layout generator. We blend the semantic layouts of source head and source body, and then inpaint the transition region by the semantic layout generator, achieving a coarse-grained head swapping. SG-LDM can further implement fine-grained head swapping with the blended layout as condition by a progressive fusion process, while preserving source head and source body with high-quality reconstruction. To this end, we design a head-cover augmentation strategy for training and a neck alignment trick for geometric realism. Importantly, we construct a new image-based head swapping benchmark and propose two tailor-designed metrics (Mask-FID and Focal-FID). Extensive experiments demonstrate the superiority of our framework. The code will be available: https://github.com/qinghew/HS-Diffusion.
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Few-shot learning (FSL), which aims to classify unseen classes with few samples, is challenging due to data scarcity. Although various generative methods have been explored for FSL, the entangled generation process of these methods exacerbates the distribution shift in FSL, thus greatly limiting the quality of generated samples. To these challenges, we propose a novel Information Bottleneck (IB) based Disentangled Generation Framework for FSL, termed as DisGenIB, that can simultaneously guarantee the discrimination and diversity of generated samples. Specifically, we formulate a novel framework with information bottleneck that applies for both disentangled representation learning and sample generation. Different from existing IB-based methods that can hardly exploit priors, we demonstrate our DisGenIB can effectively utilize priors to further facilitate disentanglement. We further prove in theory that some previous generative and disentanglement methods are special cases of our DisGenIB, which demonstrates the generality of the proposed DisGenIB. Extensive experiments on challenging FSL benchmarks confirm the effectiveness and superiority of DisGenIB, together with the validity of our theoretical analyses. Our codes will be open-source upon acceptance.
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Generalized Category Discovery (GCD) aims to recognize both known and novel categories from a set of unlabeled data, based on another dataset labeled with only known categories. Without considering differences between known and novel categories, current methods learn about them in a coupled manner, which can hurt model's generalization and discriminative ability. Furthermore, the coupled training approach prevents these models transferring category-specific knowledge explicitly from labeled data to unlabeled data, which can lose high-level semantic information and impair model performance. To mitigate above limitations, we present a novel model called Decoupled Prototypical Network (DPN). By formulating a bipartite matching problem for category prototypes, DPN can not only decouple known and novel categories to achieve different training targets effectively, but also align known categories in labeled and unlabeled data to transfer category-specific knowledge explicitly and capture high-level semantics. Furthermore, DPN can learn more discriminative features for both known and novel categories through our proposed Semantic-aware Prototypical Learning (SPL). Besides capturing meaningful semantic information, SPL can also alleviate the noise of hard pseudo labels through semantic-weighted soft assignment. Extensive experiments show that DPN outperforms state-of-the-art models by a large margin on all evaluation metrics across multiple benchmark datasets. Code and data are available at https://github.com/Lackel/DPN.
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Choosing the values of hyper-parameters in sparse Bayesian learning (SBL) can significantly impact performance. However, the hyper-parameters are normally tuned manually, which is often a difficult task. Most recently, effective automatic hyper-parameter tuning was achieved by using an empirical auto-tuner. In this work, we address the issue of hyper-parameter auto-tuning using neural network (NN)-based learning. Inspired by the empirical auto-tuner, we design and learn a NN-based auto-tuner, and show that considerable improvement in convergence rate and recovery performance can be achieved.
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