已知预测的集合，而是比单独采取的个体预测更好地执行更好。但是，对于需要重型计算资源的任务，\ texit {例如}语义细分，创建需要单独培训的学习者的集合几乎没有易行。在这项工作中，我们建议利用集合方法提供的性能提升，以增强语义分割，同时避免了集合的传统训练成本。我们的自我集成框架利用了通过特征金字塔网络方法生产的多尺度功能来提供独立解码器，从而在单个模型中创建集合。类似于集合，最终预测是每个学习者所做的预测的聚合。与以前的作品相比，我们的模型可以训练结束，减轻了传统的繁琐多阶段培训的合奏。我们的自身融合框架优于当前最先进的基准数据集ADE20K，Pascal Context和Coco-Stuff-10K用于语义细分，并且在城市景观竞争。代码将在Github.com/walbouss/senformer上使用。

在多任务学习（MTL）中，通过优化目标函数来训练多任务网络是一种常见的做法，这是特定于任务的目标函数的加权平均值。尽管该策略的计算优势很明显，但在文献中尚未研究所得损失格局的复杂性。可以说，它的优化可能比对特定于任务的目标的单独优化更加困难。在这项工作中，我们通过在不同特定于任务的目标函数上交替进行独立的梯度下降步骤来研究这种替代方案的好处，并制定了一种新颖的方式，将这种方法与最先进的优化者相结合。由于特定于任务的目标的分离是以增加计算时间为代价的，因此我们提出了一个随机的任务分组，作为更好的优化和计算效率之间的权衡。与平均目标函数和其他最先进的MTL方法相比，三个众所周知的视觉MTL数据集的实验结果在损失和标准指标上显示出更好的总体绝对性能。特别是，我们的方法在处理不同性质的任务时显示出最大的好处，并且可以更广泛地探索共享参数空间。我们还表明，我们的随机分组策略允许在这些好处和计算效率之间进行权衡。

医学图像分割或计算voxelwise语义面具是一个基本又具有挑战性的任务，用于计算体素级语义面具。为了提高编码器 - 解码器神经网络在大型临床队列中执行这项任务的能力，对比学习提供了稳定模型初始化和增强编码器而无需标签的机会。然而，多个目标对象（具有不同的语义含义）可能存在于单个图像中，这使得适应传统的对比学习方法从普遍的“图像级分类”到“像素级分段”中的问题。在本文中，我们提出了一种简单的语义感知对比学习方法，利用注意掩模来推进多对象语义分割。简而言之，我们将不同的语义对象嵌入不同的群集而不是传统的图像级嵌入。我们在与内部数据和Miccai挑战2015 BTCV数据集中的多器官医学图像分段任务中评估我们提出的方法。与目前的最先进的培训策略相比，我们拟议的管道分别产生了两种医学图像分割队列的骰子评分的大幅提高5.53％和6.09％（P值<0.01）。通过Pascal VOC 2012 DataSet进一步评估了所提出的方法的性能，并在MiOU（P值<0.01）上实现了2.75％的大幅提高。

In the era of noisy intermediate scale quantum devices, variational quantum circuits (VQCs) are currently one of the main strategies for building quantum machine learning models. These models are made up of a quantum part and a classical part. The quantum part is given by a parametrization $U$, which, in general, is obtained from the product of different quantum gates. By its turn, the classical part corresponds to an optimizer that updates the parameters of $U$ in order to minimize a cost function $C$. However, despite the many applications of VQCs, there are still questions to be answered, such as for example: What is the best sequence of gates to be used? How to optimize their parameters? Which cost function to use? How the architecture of the quantum chips influences the final results? In this article, we focus on answering the last question. We will show that, in general, the cost function will tend to a typical average value the closer the parameterization used is from a $2$-design. Therefore, the closer this parameterization is to a $2$-design, the less the result of the quantum neural network model will depend on its parametrization. As a consequence, we can use the own architecture of the quantum chips to defined the VQC parametrization, avoiding the use of additional swap gates and thus diminishing the VQC depth and the associated errors.

Dataset scaling, also known as normalization, is an essential preprocessing step in a machine learning pipeline. It is aimed at adjusting attributes scales in a way that they all vary within the same range. This transformation is known to improve the performance of classification models, but there are several scaling techniques to choose from, and this choice is not generally done carefully. In this paper, we execute a broad experiment comparing the impact of 5 scaling techniques on the performances of 20 classification algorithms among monolithic and ensemble models, applying them to 82 publicly available datasets with varying imbalance ratios. Results show that the choice of scaling technique matters for classification performance, and the performance difference between the best and the worst scaling technique is relevant and statistically significant in most cases. They also indicate that choosing an inadequate technique can be more detrimental to classification performance than not scaling the data at all. We also show how the performance variation of an ensemble model, considering different scaling techniques, tends to be dictated by that of its base model. Finally, we discuss the relationship between a model's sensitivity to the choice of scaling technique and its performance and provide insights into its applicability on different model deployment scenarios. Full results and source code for the experiments in this paper are available in a GitHub repository.\footnote{https://github.com/amorimlb/scaling\_matters}

We describe a Physics-Informed Neural Network (PINN) that simulates the flow induced by the astronomical tide in a synthetic port channel, with dimensions based on the Santos - S\~ao Vicente - Bertioga Estuarine System. PINN models aim to combine the knowledge of physical systems and data-driven machine learning models. This is done by training a neural network to minimize the residuals of the governing equations in sample points. In this work, our flow is governed by the Navier-Stokes equations with some approximations. There are two main novelties in this paper. First, we design our model to assume that the flow is periodic in time, which is not feasible in conventional simulation methods. Second, we evaluate the benefit of resampling the function evaluation points during training, which has a near zero computational cost and has been verified to improve the final model, especially for small batch sizes. Finally, we discuss some limitations of the approximations used in the Navier-Stokes equations regarding the modeling of turbulence and how it interacts with PINNs.

Language modeling, a central task in natural language processing, involves estimating a probability distribution over strings. In most cases, the estimated distribution sums to 1 over all finite strings. However, in some pathological cases, probability mass can ``leak'' onto the set of infinite sequences. In order to characterize the notion of leakage more precisely, this paper offers a measure-theoretic treatment of language modeling. We prove that many popular language model families are in fact tight, meaning that they will not leak in this sense. We also generalize characterizations of tightness proposed in previous works.

As language models (LMs) scale, they develop many novel behaviors, good and bad, exacerbating the need to evaluate how they behave. Prior work creates evaluations with crowdwork (which is time-consuming and expensive) or existing data sources (which are not always available). Here, we automatically generate evaluations with LMs. We explore approaches with varying amounts of human effort, from instructing LMs to write yes/no questions to making complex Winogender schemas with multiple stages of LM-based generation and filtering. Crowdworkers rate the examples as highly relevant and agree with 90-100% of labels, sometimes more so than corresponding human-written datasets. We generate 154 datasets and discover new cases of inverse scaling where LMs get worse with size. Larger LMs repeat back a dialog user's preferred answer ("sycophancy") and express greater desire to pursue concerning goals like resource acquisition and goal preservation. We also find some of the first examples of inverse scaling in RL from Human Feedback (RLHF), where more RLHF makes LMs worse. For example, RLHF makes LMs express stronger political views (on gun rights and immigration) and a greater desire to avoid shut down. Overall, LM-written evaluations are high-quality and let us quickly discover many novel LM behaviors.

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.

Vision Transformers convert images to sequences by slicing them into patches. The size of these patches controls a speed/accuracy tradeoff, with smaller patches leading to higher accuracy at greater computational cost, but changing the patch size typically requires retraining the model. In this paper, we demonstrate that simply randomizing the patch size at training time leads to a single set of weights that performs well across a wide range of patch sizes, making it possible to tailor the model to different compute budgets at deployment time. We extensively evaluate the resulting model, which we call FlexiViT, on a wide range of tasks, including classification, image-text retrieval, open-world detection, panoptic segmentation, and semantic segmentation, concluding that it usually matches, and sometimes outperforms, standard ViT models trained at a single patch size in an otherwise identical setup. Hence, FlexiViT training is a simple drop-in improvement for ViT that makes it easy to add compute-adaptive capabilities to most models relying on a ViT backbone architecture. Code and pre-trained models are available at https://github.com/google-research/big_vision