我们在GPU上实现了一种信任区域方法，用于使用称为JAX的新的深度学习Python库，用于非线性最小二乘曲线曲线拟合问题。我们的开源软件包JaxFit适用于无约束和约束曲线拟合问题，并允许仅在Python中定义拟合功能 - 而无需对GPU或CUDA编程的任何专业知识。由于JaxFit在GPU上运行，尽管非常易于使用，但它比基于CPU的库甚至其他基于GPU的库快得多。此外，由于JAX的深度学习基础，Jaxfit的信任区域算法中的Jacobian是通过自动分化计算的，而不是使用衍生近似值或要求用户定义拟合函数的部分导数。

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.

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.

Machine Learning models capable of handling the large datasets collected in the financial world can often become black boxes expensive to run. The quantum computing paradigm suggests new optimization techniques, that combined with classical algorithms, may deliver competitive, faster and more interpretable models. In this work we propose a quantum-enhanced machine learning solution for the prediction of credit rating downgrades, also known as fallen-angels forecasting in the financial risk management field. We implement this solution on a neutral atom Quantum Processing Unit with up to 60 qubits on a real-life dataset. We report competitive performances against the state-of-the-art Random Forest benchmark whilst our model achieves better interpretability and comparable training times. We examine how to improve performance in the near-term validating our ideas with Tensor Networks-based numerical simulations.

Identifying anomalies has become one of the primary strategies towards security and protection procedures in computer networks. In this context, machine learning-based methods emerge as an elegant solution to identify such scenarios and learn irrelevant information so that a reduction in the identification time and possible gain in accuracy can be obtained. This paper proposes a novel feature selection approach called Finite Element Machines for Feature Selection (FEMa-FS), which uses the framework of finite elements to identify the most relevant information from a given dataset. Although FEMa-FS can be applied to any application domain, it has been evaluated in the context of anomaly detection in computer networks. The outcomes over two datasets showed promising results.

Linear classifier probes are frequently utilized to better understand how neural networks function. Researchers have approached the problem of determining unit importance in neural networks by probing their learned, internal representations. Linear classifier probes identify highly selective units as the most important for network function. Whether or not a network actually relies on high selectivity units can be tested by removing them from the network using ablation. Surprisingly, when highly selective units are ablated they only produce small performance deficits, and even then only in some cases. In spite of the absence of ablation effects for selective neurons, linear decoding methods can be effectively used to interpret network function, leaving their effectiveness a mystery. To falsify the exclusive role of selectivity in network function and resolve this contradiction, we systematically ablate groups of units in subregions of activation space. Here, we find a weak relationship between neurons identified by probes and those identified by ablation. More specifically, we find that an interaction between selectivity and the average activity of the unit better predicts ablation performance deficits for groups of units in AlexNet, VGG16, MobileNetV2, and ResNet101. Linear decoders are likely somewhat effective because they overlap with those units that are causally important for network function. Interpretability methods could be improved by focusing on causally important units.

多实施学习（MIL）被广泛用于对病理整体幻灯片图像（WSIS）的计算机辅助解释，以解决缺乏像素或贴片的注释。通常，这种方法直接应用“自然图像驱动”的MIL算法，该算法忽略了WSIS的多尺度（即金字塔）性质。现成的MIL算法通常部署在单个WSIS（例如20x放大倍率）上，而人类病理学家通常以多尺度的方式汇总全球和局部模式（例如，通过放大不同大型）。在这项研究中，我们提出了一种新型的跨尺度注意机制，以明确地将尺度间相互作用汇总到单个MIL网络的克罗恩病（CD）（CD），这是炎症性肠病的一种形式。本文的贡献是两个方面：（1）提出了一种跨尺度注意机制，以从不同分辨率的多尺度相互作用汇总特征； （2）生成差异多尺度注意的可视化，以定位可解释的病变模式。通过训练来自20名CD患者的约250,000 H＆E染色的上升结肠（AC）斑块，在不同尺度上训练30个健康对照样品，我们的方法在曲线下（AUC）得分为0.8924，与基线模型相比达到0.8924。官方实施可在https://github.com/hrlblab/cs-mil上公开获得。

做出公正的决定对于在社交环境中实施机器学习算法至关重要。在这项工作中，我们考虑了反事实公平的著名定义[Kusner等，Neurips，2017]。首先，我们表明一种满足反事实公平的算法也满足人口统计学的偏见，这是一个更简单的公平限制。同样，我们表明所有满足人口统计学奇偶校验的算法都可以进行微不足道的修改以满足反事实公平。总之，我们的结果表明，反事实公平基本上等同于人口统计学，这对不断增长的反事实公平工作具有重要意义。然后，我们从经验上验证了我们的理论发现，分析了三种现有的算法，以针对三个简单的基准分析反事实公平。我们发现，在几个数据集上，两种简单的基准算法在公平，准确性和效率方面都优于所有三种现有算法。我们的分析使我们实现了一个具体的公平目标：保留受保护群体中个人的顺序。我们认为，围绕个人在受保护群体中的秩序的透明度使公平的算法更加值得信赖。根据设计，两个简单的基准算法满足了这个目标，而现有的反事实公平算法则不能。

序列在许多真实的情况下出现；因此，识别符号生成背后的机制对于理解许多复杂系统至关重要。本文分析了在网络拓扑上行走的代理产生的序列。鉴于在许多实际情况下，生成序列的基础过程是隐藏的，我们研究了通过共发生方法重建网络是否对恢复网络拓扑和代理动力学生成序列很有用。我们发现，重建网络的表征提供了有关用于创建序列的过程和拓扑的有价值的信息。在考虑16种网络拓扑和代理动力学组合的机器学习方法中，我们获得了87％的精度，序列生成的序列少于访问量的少于40％。事实证明，较大的序列可以生成改进的机器学习模型。我们的发现表明，可以扩展所提出的方法以对序列进行分类并了解序列产生背后的机制。