In this paper we study the smooth strongly convex minimization problem $\min_{x}\min_y f(x,y)$. The existing optimal first-order methods require $\mathcal{O}(\sqrt{\max\{\kappa_x,\kappa_y\}} \log 1/\epsilon)$ of computations of both $\nabla_x f(x,y)$ and $\nabla_y f(x,y)$, where $\kappa_x$ and $\kappa_y$ are condition numbers with respect to variable blocks $x$ and $y$. We propose a new algorithm that only requires $\mathcal{O}(\sqrt{\kappa_x} \log 1/\epsilon)$ of computations of $\nabla_x f(x,y)$ and $\mathcal{O}(\sqrt{\kappa_y} \log 1/\epsilon)$ computations of $\nabla_y f(x,y)$. In some applications $\kappa_x \gg \kappa_y$, and computation of $\nabla_y f(x,y)$ is significantly cheaper than computation of $\nabla_x f(x,y)$. In this case, our algorithm substantially outperforms the existing state-of-the-art methods.
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本文是对解决平滑(强)单调随机变化不平等的方法的调查。首先,我们给出了随机方法最终发展的确定性基础。然后,我们回顾了通用随机配方的方法,并查看有限的总和设置。本文的最后部分致力于各种算法的各种(不一定是随机)的变化不平等现象。
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受到Mishchenko等人(2022)的最新突破的启发,他们首次表明局部梯度步骤可以导致可证明的通信加速,我们提出了一种替代算法,该算法获得了与他们的方法相同的通信加速度(Proxsskip)。但是,我们的方法非常不同:它基于Chambolle和Pock(2011)的著名方法,并具有多种不平凡的修改:i)我们允许通过适当的强烈凸出功能的代理操作员进行不精确的计算。基于梯度的方法(例如,GD,Fast GD或FSFOM),ii)我们对双重更新步骤进行仔细的修改,以保留线性收敛。我们的一般结果为强凸孔座鞍点问题提供了新的最先进率,其双线性耦合为特征,其特征是双重功能缺乏平滑度。当应用于联邦学习时,我们获得了Proxskip的理论上更好的替代方案:我们的方法需要更少的本地步骤($ O(\ kappa^{1/3})$或$ o(\ kappa^{1/4})$,与Proxskip的$ O(\ kappa^{1/2})$相比,并执行确定性的本地步骤。像Proxskip一样,我们的方法可以应用于连接网络的优化,我们在这里也获得了理论改进。
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具有自适应缩放不同功能的方法在解决鞍点问题方面起着关键作用,这主要是由于亚当在解决对抗机器学习问题(包括gans训练)方面的受欢迎程度。本文对解决SPPS的以下缩放技术进行了理论分析:众所周知的Adam和Rmsprop缩放以及基于Hutchison近似的较新的Adahessian和Oasis。我们将额外的梯度及其改进的版本带有负动量作为基本方法。关于gan的实验研究不仅对亚当,而且对其他不太流行的方法显示出良好的适用性。
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在本文中,我们研究了一个凸凹马鞍点问题$ \ min_x \ max_y f(x)+ y ^ \ top \ mathbf {a} x - g(y)$,其中$ f(x)$和$ g(y)$是平滑和凸的功能。我们提出了一种加速的原始 - 双梯度方法,用于解决该问题(i)在匹配较低复杂性绑定的强 - 凸强 - 凹形方案中实现最佳线性收敛速率(Zhang等,2021)和(ii)在只有其中一个函数$ f(x)$和$ g(y)$的情况下实现加速的线性收敛速率,而甚至没有它们。最后,我们获得了一种线性收敛算法,用于一般平滑和凸凹骑马点问题$ \ min_x \ max_y f(x,y)$,不需要强大的凸起或强凹面。
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We present a novel dataset named as HPointLoc, specially designed for exploring capabilities of visual place recognition in indoor environment and loop detection in simultaneous localization and mapping. The loop detection sub-task is especially relevant when a robot with an on-board RGB-D camera can drive past the same place (``Point") at different angles. The dataset is based on the popular Habitat simulator, in which it is possible to generate photorealistic indoor scenes using both own sensor data and open datasets, such as Matterport3D. To study the main stages of solving the place recognition problem on the HPointLoc dataset, we proposed a new modular approach named as PNTR. It first performs an image retrieval with the Patch-NetVLAD method, then extracts keypoints and matches them using R2D2, LoFTR or SuperPoint with SuperGlue, and finally performs a camera pose optimization step with TEASER++. Such a solution to the place recognition problem has not been previously studied in existing publications. The PNTR approach has shown the best quality metrics on the HPointLoc dataset and has a high potential for real use in localization systems for unmanned vehicles. The proposed dataset and framework are publicly available: https://github.com/metra4ok/HPointLoc.
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Domain adaptation of GANs is a problem of fine-tuning the state-of-the-art GAN models (e.g. StyleGAN) pretrained on a large dataset to a specific domain with few samples (e.g. painting faces, sketches, etc.). While there are a great number of methods that tackle this problem in different ways there are still many important questions that remain unanswered. In this paper, we provide a systematic and in-depth analysis of the domain adaptation problem of GANs, focusing on the StyleGAN model. First, we perform a detailed exploration of the most important parts of StyleGAN that are responsible for adapting the generator to a new domain depending on the similarity between the source and target domains. In particular, we show that affine layers of StyleGAN can be sufficient for fine-tuning to similar domains. Second, inspired by these findings, we investigate StyleSpace to utilize it for domain adaptation. We show that there exist directions in the StyleSpace that can adapt StyleGAN to new domains. Further, we examine these directions and discover their many surprising properties. Finally, we leverage our analysis and findings to deliver practical improvements and applications in such standard tasks as image-to-image translation and cross-domain morphing.
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By transferring knowledge from large, diverse, task-agnostic datasets, modern machine learning models can solve specific downstream tasks either zero-shot or with small task-specific datasets to a high level of performance. While this capability has been demonstrated in other fields such as computer vision, natural language processing or speech recognition, it remains to be shown in robotics, where the generalization capabilities of the models are particularly critical due to the difficulty of collecting real-world robotic data. We argue that one of the keys to the success of such general robotic models lies with open-ended task-agnostic training, combined with high-capacity architectures that can absorb all of the diverse, robotic data. In this paper, we present a model class, dubbed Robotics Transformer, that exhibits promising scalable model properties. We verify our conclusions in a study of different model classes and their ability to generalize as a function of the data size, model size, and data diversity based on a large-scale data collection on real robots performing real-world tasks. The project's website and videos can be found at robotics-transformer.github.io
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Artificial intelligence methods including deep neural networks (DNN) can provide rapid molecular classification of tumors from routine histology with accuracy that matches or exceeds human pathologists. Discerning how neural networks make their predictions remains a significant challenge, but explainability tools help provide insights into what models have learned when corresponding histologic features are poorly defined. Here, we present a method for improving explainability of DNN models using synthetic histology generated by a conditional generative adversarial network (cGAN). We show that cGANs generate high-quality synthetic histology images that can be leveraged for explaining DNN models trained to classify molecularly-subtyped tumors, exposing histologic features associated with molecular state. Fine-tuning synthetic histology through class and layer blending illustrates nuanced morphologic differences between tumor subtypes. Finally, we demonstrate the use of synthetic histology for augmenting pathologist-in-training education, showing that these intuitive visualizations can reinforce and improve understanding of histologic manifestations of tumor biology.
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There is an increasing need in our society to achieve faster advances in Science to tackle urgent problems, such as climate changes, environmental hazards, sustainable energy systems, pandemics, among others. In certain domains like chemistry, scientific discovery carries the extra burden of assessing risks of the proposed novel solutions before moving to the experimental stage. Despite several recent advances in Machine Learning and AI to address some of these challenges, there is still a gap in technologies to support end-to-end discovery applications, integrating the myriad of available technologies into a coherent, orchestrated, yet flexible discovery process. Such applications need to handle complex knowledge management at scale, enabling knowledge consumption and production in a timely and efficient way for subject matter experts (SMEs). Furthermore, the discovery of novel functional materials strongly relies on the development of exploration strategies in the chemical space. For instance, generative models have gained attention within the scientific community due to their ability to generate enormous volumes of novel molecules across material domains. These models exhibit extreme creativity that often translates in low viability of the generated candidates. In this work, we propose a workbench framework that aims at enabling the human-AI co-creation to reduce the time until the first discovery and the opportunity costs involved. This framework relies on a knowledge base with domain and process knowledge, and user-interaction components to acquire knowledge and advise the SMEs. Currently,the framework supports four main activities: generative modeling, dataset triage, molecule adjudication, and risk assessment.
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