We study the task of learning state representations from potentially high-dimensional observations, with the goal of controlling an unknown partially observable system. We pursue a direct latent model learning approach, where a dynamic model in some latent state space is learned by predicting quantities directly related to planning (e.g., costs) without reconstructing the observations. In particular, we focus on an intuitive cost-driven state representation learning method for solving Linear Quadratic Gaussian (LQG) control, one of the most fundamental partially observable control problems. As our main results, we establish finite-sample guarantees of finding a near-optimal state representation function and a near-optimal controller using the directly learned latent model. To the best of our knowledge, despite various empirical successes, prior to this work it was unclear if such a cost-driven latent model learner enjoys finite-sample guarantees. Our work underscores the value of predicting multi-step costs, an idea that is key to our theory, and notably also an idea that is known to be empirically valuable for learning state representations.

The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.

Weakly-supervised text classification aims to train a classifier using only class descriptions and unlabeled data. Recent research shows that keyword-driven methods can achieve state-of-the-art performance on various tasks. However, these methods not only rely on carefully-crafted class descriptions to obtain class-specific keywords but also require substantial amount of unlabeled data and takes a long time to train. This paper proposes FastClass, an efficient weakly-supervised classification approach. It uses dense text representation to retrieve class-relevant documents from external unlabeled corpus and selects an optimal subset to train a classifier. Compared to keyword-driven methods, our approach is less reliant on initial class descriptions as it no longer needs to expand each class description into a set of class-specific keywords. Experiments on a wide range of classification tasks show that the proposed approach frequently outperforms keyword-driven models in terms of classification accuracy and often enjoys orders-of-magnitude faster training speed.

Previous databases have been designed to further the development of fake audio detection. However, fake utterances are mostly generated by altering timbre, prosody, linguistic content or channel noise of original audios. They ignore a fake situation, in which the attacker manipulates an acoustic scene of the original audio with another forgery one. It will pose a major threat to our society if some people misuse the manipulated audio with malicious purpose. Therefore, this motivates us to fill in the gap. This paper designs such a dataset for scene fake audio detection (SceneFake). A manipulated audio in the SceneFake dataset involves only tampering the acoustic scene of an utterance by using speech enhancement technologies. We can not only detect fake utterances on a seen test set but also evaluate the generalization of fake detection models to unseen manipulation attacks. Some benchmark results are described on the SceneFake dataset. Besides, an analysis of fake attacks with different speech enhancement technologies and signal-to-noise ratios are presented on the dataset. The results show that scene manipulated utterances can not be detected reliably by the existing baseline models of ASVspoof 2019. Furthermore, the detection of unseen scene manipulation audio is still challenging.

在过去的几年中，用于计算机视觉的深度学习技术的快速发展极大地促进了医学图像细分的性能（Mediseg）。但是，最近的梅赛格出版物通常集中于主要贡献的演示（例如，网络体系结构，培训策略和损失功能），同时不知不觉地忽略了一些边缘实施细节（也称为“技巧”），导致了潜在的问题，导致了潜在的问题。不公平的实验结果比较。在本文中，我们为不同的模型实施阶段（即，预培训模型，数据预处理，数据增强，模型实施，模型推断和结果后处理）收集了一系列Mediseg技巧，并在实验中探索了有效性这些技巧在一致的基线模型上。与仅关注分割模型的优点和限制分析的纸驱动调查相比，我们的工作提供了大量的可靠实验，并且在技术上更可操作。通过对代表性2D和3D医疗图像数据集的广泛实验结果，我们明确阐明了这些技巧的效果。此外，根据调查的技巧，我们还开源了一个强大的梅德西格存储库，其每个组件都具有插件的优势。我们认为，这项里程碑的工作不仅完成了对最先进的Mediseg方法的全面和互补的调查，而且还提供了解决未来医学图像处理挑战的实用指南，包括但不限于小型数据集学习，课程不平衡学习，多模式学习和领域适应。该代码已在以下网址发布：https：//github.com/hust-linyi/mediseg

进行了许多有效的尝试进行了DeepFake音频检测。但是，他们只能区分真实和假货。对于许多实际的应用程序方案，还需要哪种工具或算法生成DeepFake音频。这提出了一个问题：我们可以检测到DeepFake音频的系统指纹吗？因此，本文进行了初步研究，以检测DeepFake音频的系统指纹。实验是从五个最新的深入学习语音合成系统的DeepFake音频数据集上进行的。结果表明，LFCC功能相对适合系统指纹检测。此外，RESNET在基于LCNN和X-Vector模型中获得了最佳检测结果。T-SNE可视化表明，不同的语音合成系统会生成不同的系统指纹。

现有的假音频检测系统通常依靠专家经验来设计声学功能或手动设计网络结构的超参数。但是，人工调整参数可能会对结果产生相对明显的影响。几乎不可能手动设置最佳参数集。因此，本文提出了一种完全自动化的终端伪造音频检测方法。我们首先使用WAV2VEC预训练模型来获得语音的高级表示。此外，对于网络结构，我们使用了名为Light-Darts的可区分体系结构搜索（飞镖）的修改版本。它学习了深厚的语音表示，同时自动学习和优化包括卷积操作和残留块组成的复杂神经结构。 ASVSPOOF 2019 LA数据集的实验结果表明，我们提出的系统达到的错误率（EER）为1.08％，这表现优于最先进的单个系统。

样本分配在现代对象检测方法中起着重要的作用。但是，大多数现有的方法都依靠手动设计来分配正 /负样本，这些样本并未明确建立样本分配和对象检测性能之间的关系。在这项工作中，我们提出了一种基于高参数搜索的新型动态样本分配方案。我们首先将分配给每个地面真理的正样本的数量定义为超参数，并采用替代优化算法来得出最佳选择。然后，我们设计一个动态的样本分配过程，以动态选择每个训练迭代中的最佳阳性数量。实验表明，所得的HPS-DET在不同对象检测基线的基线上带来了改善的性能。此外，我们分析了在不同数据集之间和不同骨架之间转移的高参数可重复使用性，以进行对象检测，这表现出我们方法的优势和多功能性。

在恶劣天气下降雪场景的图像恢复是一项艰巨的任务。雪图像具有复杂的降解，并在干净的图像上混乱，改变了干净的图像的分布。以前基于CNN的方法由于缺乏特定的全球建模能力，因此在恢复雪场景中完全恢复了雪场的挑战。在本文中，我们将视觉变压器应用于从单个图像中去除积雪的任务。具体而言，我们建议沿通道拆分的并行网络体系结构分别执行本地功能改进和全局信息建模。我们利用频道洗牌操作来结合其各自的优势以增强网络性能。其次，我们提出了MSP模块，该模块利用多规模的AVGPOOL来汇总不同大小的信息，并同时对多头自我注意力进行多尺度投影自我注意，以提高模型在不同规模下降下的表示能力。最后，我们设计了一个轻巧，简单的本地捕获模块，可以完善模型的本地捕获能力。在实验部分，我们进行了广泛的实验以证明我们方法的优越性。我们比较了三个雪场数据集上的先前清除方法。实验结果表明，我们的方法超过了更少的参数和计算的最新方法。在CSD测试数据集上，我们实现了1.99dB和SSIM 0.03的实质增长。在SRR和SNOW100K数据集上，与Transweather方法相比，我们还增加了2.47dB和1.62dB，在SSIM中提高了0.03。在视觉比较部分中，我们的MSP形式比现有方法获得了更好的视觉效果，证明了我们方法的可用性。

在冬季场景中，在雪下拍摄的图像的降解可能非常复杂，其中雪降解的空间分布因图像而异。最近的方法采用深层神经网络，直接从雪图像中恢复清洁的场景。但是，由于复杂的雪降解差异导致悖论，实时实现可靠的高清图像是一个巨大的挑战。我们开发了一种新型有效的金字塔网络，具有非对称编码器架构，用于实时高清图像。我们提出的网络的一般思想是通过功能中的多尺度特征流充分利用多尺度的特征流。与以前最先进的方法相比，我们的方法实现了更好的复杂性 - 性能取舍，并有效地处理了高清和超高清图像的处理困难。在三个大规模图像上进行的广泛实验表明，我们的方法超过了所有最新方法，既有数量又定性地超过了大幅度，从而将PSNR度量从31.76 dB提高到34.10 dB，升至34.10 dB。 SRRS测试数据集上的28.29 dB至30.87 dB。