有效地对远程依赖性建模是序列建模的重要目标。最近，使用结构化状态空间序列（S4）层的模型在许多远程任务上实现了最先进的性能。 S4层将线性状态空间模型（SSM）与深度学习技术结合在一起，并利用HIPPO框架进行在线功能近似以实现高性能。但是，该框架导致了架构约束和计算困难，使S4方法变得复杂，可以理解和实施。我们重新审视这样的想法，即遵循河马框架对于高性能是必要的。具体而言，我们替换了许多独立的单输入单输出（SISO）SSM的库S4层与一个多输入的多输出（MIMO）SSM一起使用，并具有降低的潜在尺寸。 MIMO系统的缩小潜在维度允许使用有效的并行扫描，从而简化了将S5层应用于序列到序列转换所需的计算。此外，我们将S5 SSM的状态矩阵初始化，其近似与S4 SSMS使用的河马级矩阵近似，并表明这是MIMO设置的有效初始化。 S5与S4在远程任务上的表现相匹配，包括在远程竞技场基准的套件中平均达到82.46％，而S4的80.48％和最佳的变压器变体的61.41％。

顺序蒙特卡洛（SMC）是状态空间模型的推理算法，通过从一系列中间目标分布进行采样来近似后验。目标分布通常被选择为过滤分布，但是这些忽略了未来观察结果的信息，从而导致推理和模型学习的实际和理论局限性。我们介绍了SIXO，这种方法将学习近似平滑分布的目标，并结合了所有观测值的信息。关键思想是使用密度比估计来拟合将过滤分布扭曲到平滑分布中的功能。然后，我们将SMC与这些学习的目标一起使用，以定义模型和建议学习的变异目标。六体的产量可证明更紧密的对数边缘下限，并在各种域中提供了更准确的后验推断和参数估计。

Neyman-Scott processes (NSPs) are point process models that generate clusters of points in time or space. They are natural models for a wide range of phenomena, ranging from neural spike trains to document streams. The clustering property is achieved via a doubly stochastic formulation: first, a set of latent events is drawn from a Poisson process; then, each latent event generates a set of observed data points according to another Poisson process. This construction is similar to Bayesian nonparametric mixture models like the Dirichlet process mixture model (DPMM) in that the number of latent events (i.e. clusters) is a random variable, but the point process formulation makes the NSP especially well suited to modeling spatiotemporal data. While many specialized algorithms have been developed for DPMMs, comparatively fewer works have focused on inference in NSPs. Here, we present novel connections between NSPs and DPMMs, with the key link being a third class of Bayesian mixture models called mixture of finite mixture models (MFMMs). Leveraging this connection, we adapt the standard collapsed Gibbs sampling algorithm for DPMMs to enable scalable Bayesian inference on NSP models. We demonstrate the potential of Neyman-Scott processes on a variety of applications including sequence detection in neural spike trains and event detection in document streams.

经常性的神经网络（RNNS）是用于处理时间序列数据的强大模型，但了解它们如何运作仍然具有挑战性。提高这种理解对机器学习和神经科学社区的大量兴趣。逆向工程框架训练的RNN通过在其固定点周围线性化提供了洞察力，但该方法具有重大挑战。这些包括在使用线性化动态重建非线性动态时，选择在研究RNN动态和误差累积时难以扩展的固定点。我们提出了一种通过使用新型切换线性动态系统（SLD）制剂的RNN共同训练RNN来克服这些限制的新模型。共同训练的RNN的一阶泰勒系列扩展和训练拾取RNN的固定点的辅助功能管理SLDS动态。结果是训练有素的SLDS变体，其与RNN相近，可以为状态空间中的每个点产生固定点的辅助函数，以及其动态已经规程的训练有素的非线性RNN，使得其一阶项执行计算， 如果可能的话。该模型删除了培训后的固定点优化，并允许我们明确地研究SLD在状态空间中的任何点的学习动态。它还概括了SLDS模型，以在交换机共享参数的同时将SLD模型转换为切换点的连续歧管。我们以与先前的工作逆向工程RNN相关的两个合成任务验证模型的实用程序。然后，我们表明我们的模型可以用作更复杂的架构中的替换，例如LFAD，并应用该LFADS杂种以分析非人类灵长类动物的电机系统的单试尖峰活动。

了解生物和人造网络的运作仍然是一个艰难而重要的挑战。为了确定一般原则，研究人员越来越有兴趣测量培训的大量网络，或者在培训或生物学地适应类似的任务。现在需要一种标准化的分析工具来确定网络级协变量 - 例如架构，解剖脑区和模型生物 - 影响神经表示（隐藏层激活）。在这里，我们通过定义量化代表性异化的广泛的公制空间，为这些分析提供严格的基础。使用本框架，我们根据规范相关分析修改现有的代表性相似度量，以满足三角形不等式，制定致扫描层中的感应偏差的新型度量，并识别使网络表示能够结合到基本上的近似的欧几里德嵌入物。货架机学习方法。我们展示了来自生物学（Allen Institute脑观测所）和深度学习（NAS-BENCH-101）的大规模数据集的这些方法。在这样做时，我们识别在解剖特征和模型性能方面可解释的神经表现之间的关系。

Data compression is becoming critical for storing scientific data because many scientific applications need to store large amounts of data and post process this data for scientific discovery. Unlike image and video compression algorithms that limit errors to primary data, scientists require compression techniques that accurately preserve derived quantities of interest (QoIs). This paper presents a physics-informed compression technique implemented as an end-to-end, scalable, GPU-based pipeline for data compression that addresses this requirement. Our hybrid compression technique combines machine learning techniques and standard compression methods. Specifically, we combine an autoencoder, an error-bounded lossy compressor to provide guarantees on raw data error, and a constraint satisfaction post-processing step to preserve the QoIs within a minimal error (generally less than floating point error). The effectiveness of the data compression pipeline is demonstrated by compressing nuclear fusion simulation data generated by a large-scale fusion code, XGC, which produces hundreds of terabytes of data in a single day. Our approach works within the ADIOS framework and results in compression by a factor of more than 150 while requiring only a few percent of the computational resources necessary for generating the data, making the overall approach highly effective for practical scenarios.

Algorithms that involve both forecasting and optimization are at the core of solutions to many difficult real-world problems, such as in supply chains (inventory optimization), traffic, and in the transition towards carbon-free energy generation in battery/load/production scheduling in sustainable energy systems. Typically, in these scenarios we want to solve an optimization problem that depends on unknown future values, which therefore need to be forecast. As both forecasting and optimization are difficult problems in their own right, relatively few research has been done in this area. This paper presents the findings of the ``IEEE-CIS Technical Challenge on Predict+Optimize for Renewable Energy Scheduling," held in 2021. We present a comparison and evaluation of the seven highest-ranked solutions in the competition, to provide researchers with a benchmark problem and to establish the state of the art for this benchmark, with the aim to foster and facilitate research in this area. The competition used data from the Monash Microgrid, as well as weather data and energy market data. It then focused on two main challenges: forecasting renewable energy production and demand, and obtaining an optimal schedule for the activities (lectures) and on-site batteries that lead to the lowest cost of energy. The most accurate forecasts were obtained by gradient-boosted tree and random forest models, and optimization was mostly performed using mixed integer linear and quadratic programming. The winning method predicted different scenarios and optimized over all scenarios jointly using a sample average approximation method.

Lack of factual correctness is an issue that still plagues state-of-the-art summarization systems despite their impressive progress on generating seemingly fluent summaries. In this paper, we show that factual inconsistency can be caused by irrelevant parts of the input text, which act as confounders. To that end, we leverage information-theoretic measures of causal effects to quantify the amount of confounding and precisely quantify how they affect the summarization performance. Based on insights derived from our theoretical results, we design a simple multi-task model to control such confounding by leveraging human-annotated relevant sentences when available. Crucially, we give a principled characterization of data distributions where such confounding can be large thereby necessitating the use of human annotated relevant sentences to generate factual summaries. Our approach improves faithfulness scores by 20\% over strong baselines on AnswerSumm \citep{fabbri2021answersumm}, a conversation summarization dataset where lack of faithfulness is a significant issue due to the subjective nature of the task. Our best method achieves the highest faithfulness score while also achieving state-of-the-art results on standard metrics like ROUGE and METEOR. We corroborate these improvements through human evaluation.

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.

This paper describes Waymo's Collision Avoidance Testing (CAT) methodology: a scenario-based testing method that evaluates the safety of the Waymo Driver Automated Driving Systems' (ADS) intended functionality in conflict situations initiated by other road users that require urgent evasive maneuvers. Because SAE Level 4 ADS are responsible for the dynamic driving task (DDT), when engaged, without immediate human intervention, evaluating a Level 4 ADS using scenario-based testing is difficult due to the potentially infinite number of operational scenarios in which hazardous situations may unfold. To that end, in this paper we first describe the safety test objectives for the CAT methodology, including the collision and serious injury metrics and the reference behavior model representing a non-impaired eyes on conflict human driver used to form an acceptance criterion. Afterward, we introduce the process for identifying potentially hazardous situations from a combination of human data, ADS testing data, and expert knowledge about the product design and associated Operational Design Domain (ODD). The test allocation and execution strategy is presented next, which exclusively utilize simulations constructed from sensor data collected on a test track, real-world driving, or from simulated sensor data. The paper concludes with the presentation of results from applying CAT to the fully autonomous ride-hailing service that Waymo operates in San Francisco, California and Phoenix, Arizona. The iterative nature of scenario identification, combined with over ten years of experience of on-road testing, results in a scenario database that converges to a representative set of responder role scenarios for a given ODD. Using Waymo's virtual test platform, which is calibrated to data collected as part of many years of ADS development, the CAT methodology provides a robust and scalable safety evaluation.