数值模拟中信息丢失可能来自各种来源，同时求解离散的部分微分方程。特别地，与等效的64位模拟相比，使用低精确的16位浮点算术进行模拟时，与精度相关的错误可能会积累在关注量中。在这里，低精度计算所需的资源要比高精度计算要低得多。最近提出的几种机器学习（ML）技术已成功纠正空间离散化引起的错误。在这项工作中，我们扩展了这些技术，以改善使用低数值精度进行的计算流体动力学（CFD）模拟。我们首先量化了在Kolmogorov强制湍流测试案例中累积的精度相关误差。随后，我们采用了卷积神经网络以及执行16位算术的完全可区分的数值求解器，以学习紧密耦合的ML-CFD混合求解器。与16位求解器相比，我们证明了ML-CFD混合求解器在减少速度场中的误差积累并在较高频率下改善动能光谱的功效。

In recent years multi-label, multi-class video action recognition has gained significant popularity. While reasoning over temporally connected atomic actions is mundane for intelligent species, standard artificial neural networks (ANN) still struggle to classify them. In the real world, atomic actions often temporally connect to form more complex composite actions. The challenge lies in recognising composite action of varying durations while other distinct composite or atomic actions occur in the background. Drawing upon the success of relational networks, we propose methods that learn to reason over the semantic concept of objects and actions. We empirically show how ANNs benefit from pretraining, relational inductive biases and unordered set-based latent representations. In this paper we propose deep set conditioned I3D (SCI3D), a two stream relational network that employs latent representation of state and visual representation for reasoning over events and actions. They learn to reason about temporally connected actions in order to identify all of them in the video. The proposed method achieves an improvement of around 1.49% mAP in atomic action recognition and 17.57% mAP in composite action recognition, over a I3D-NL baseline, on the CATER dataset.

Motivated by mitigating potentially harmful impacts of technologies, the AI community has formulated and accepted mathematical definitions for certain pillars of accountability: e.g. privacy, fairness, and model transparency. Yet, we argue this is fundamentally misguided because these definitions are imperfect, siloed constructions of the human values they hope to proxy, while giving the guise that those values are sufficiently embedded in our technologies. Under popularized methods, tensions arise when practitioners attempt to achieve each pillar of fairness, privacy, and transparency in isolation or simultaneously. In this position paper, we push for redirection. We argue that the AI community needs to consider all the consequences of choosing certain formulations of these pillars -- not just the technical incompatibilities, but also the effects within the context of deployment. We point towards sociotechnical research for frameworks for the latter, but push for broader efforts into implementing these in practice.

Developing and least developed countries face the dire challenge of ensuring that each child in their country receives required doses of vaccination, adequate nutrition and proper medication. International agencies such as UNICEF, WHO and WFP, among other organizations, strive to find innovative solutions to determine which child has received the benefits and which have not. Biometric recognition systems have been sought out to help solve this problem. To that end, this report establishes a baseline accuracy of a commercial contactless palmprint recognition system that may be deployed for recognizing children in the age group of one to five years old. On a database of contactless palmprint images of one thousand unique palms from 500 children, we establish SOTA authentication accuracy of 90.85% @ FAR of 0.01%, rank-1 identification accuracy of 99.0% (closed set), and FPIR=0.01 @ FNIR=0.3 for open-set identification using PalmMobile SDK from Armatura.

Reliable uncertainty quantification in deep neural networks is very crucial in safety-critical applications such as automated driving for trustworthy and informed decision-making. Assessing the quality of uncertainty estimates is challenging as ground truth for uncertainty estimates is not available. Ideally, in a well-calibrated model, uncertainty estimates should perfectly correlate with model error. We propose a novel error aligned uncertainty optimization method and introduce a trainable loss function to guide the models to yield good quality uncertainty estimates aligning with the model error. Our approach targets continuous structured prediction and regression tasks, and is evaluated on multiple datasets including a large-scale vehicle motion prediction task involving real-world distributional shifts. We demonstrate that our method improves average displacement error by 1.69% and 4.69%, and the uncertainty correlation with model error by 17.22% and 19.13% as quantified by Pearson correlation coefficient on two state-of-the-art baselines.

Changes in real-world dynamic processes are often described in terms of differences in energies $\textbf{E}(\underline{\alpha})$ of a set of spectral-bands $\underline{\alpha}$. Given continuous spectra of two classes $A$ and $B$, or in general, two stochastic processes $S^{(A)}(f)$ and $S^{(B)}(f)$, $f \in \mathbb{R}^+$, we address the ubiquitous problem of identifying a subset of intervals of $f$ called spectral-bands $\underline{\alpha} \subset \mathbb{R}^+$ such that the energies $\textbf{E}(\underline{\alpha})$ of these bands can optimally discriminate between the two classes. We introduce EGO-MDA, an unsupervised method to identify optimal spectral-bands $\underline{\alpha}^*$ for given samples of spectra from two classes. EGO-MDA employs a statistical approach that iteratively minimizes an adjusted multinomial log-likelihood (deviance) criterion $\mathcal{D}(\underline{\alpha},\mathcal{M})$. Here, Mixture Discriminant Analysis (MDA) aims to derive MLE of two GMM distribution parameters, i.e., $\mathcal{M}^* = \underset{\mathcal{M}}{\rm argmin}~\mathcal{D}(\underline{\alpha}, \mathcal{M})$ and identify a classifier that optimally discriminates between two classes for a given spectral representation. The Efficient Global Optimization (EGO) finds the spectral-bands $\underline{\alpha}^* = \underset{\underline{\alpha}}{\rm argmin}~\mathcal{D}(\underline{\alpha},\mathcal{M})$ for given GMM parameters $\mathcal{M}$. For pathological cases of low separation between mixtures and model misspecification, we discuss the effect of the sample size and the number of iterations on the estimates of parameters $\mathcal{M}$ and therefore the classifier performance. A case study on a synthetic data set is provided. In an engineering application of optimal spectral-banding for anomaly tracking, EGO-MDA achieved at least 70% improvement in the median deviance relative to other methods tested.

Finding an initial noise vector that produces an input image when fed into the diffusion process (known as inversion) is an important problem in denoising diffusion models (DDMs), with applications for real image editing. The state-of-the-art approach for real image editing with inversion uses denoising diffusion implicit models (DDIMs) to deterministically noise the image to the intermediate state along the path that the denoising would follow given the original conditioning. However, DDIM inversion for real images is unstable as it relies on local linearization assumptions, which result in the propagation of errors, leading to incorrect image reconstruction and loss of content. To alleviate these problems, we propose Exact Diffusion Inversion via Coupled Transformations (EDICT), an inversion method that draws inspiration from affine coupling layers. EDICT enables mathematically exact inversion of real and model-generated images by maintaining two coupled noise vectors which are used to invert each other in an alternating fashion. Using Stable Diffusion, a state-of-the-art latent diffusion model, we demonstrate that EDICT successfully reconstructs real images with high fidelity. On complex image datasets like MS-COCO, EDICT reconstruction significantly outperforms DDIM, improving the mean square error of reconstruction by a factor of two. Using noise vectors inverted from real images, EDICT enables a wide range of image edits--from local and global semantic edits to image stylization--while maintaining fidelity to the original image structure. EDICT requires no model training/finetuning, prompt tuning, or extra data and can be combined with any pretrained DDM. Code is available at https://github.com/salesforce/EDICT.

自动化车辆功能最佳接受和舒适性的关键因素是驾驶方式。自动化和驱动程序偏爱的驾驶方式之间的不匹配可以使用户更频繁地接管甚至禁用自动化功能。这项工作建议用多模式信号识别用户驾驶样式偏好，因此该车辆可以以连续自动的方式匹配用户偏好。我们对36名参与者进行了驾驶模拟器研究，并收集了广泛的多模式数据，包括行为，生理和情境数据。这包括眼目光，转向抓地力，驾驶演习，制动和节气门踏板输入以及距踏板的脚距离，瞳孔直径，电流皮肤反应，心率和情境驱动驱动环境。然后，我们建立了机器学习模型来识别首选的驾驶方式，并确认所有模式对于识别用户偏好都很重要。这项工作为自动车辆的隐性自适应驾驶风格铺平了道路。

制作对抗性攻击的大多数方法都集中在具有单个主体对象的场景上（例如，来自Imagenet的图像）。另一方面，自然场景包括多个在语义上相关的主要对象。因此，探索设计攻击策略至关重要，这些攻击策略超出了在单对象场景上学习或攻击单对象受害者分类器。由于其固有的属性将扰动向未知模型的强大可传递性强，因此本文介绍了使用生成模型对多对象场景的对抗性攻击的第一种方法。为了代表输入场景中不同对象之间的关系，我们利用开源的预训练的视觉语言模型剪辑（对比语言图像 - 预训练），并动机利用语言中的编码语义来利用编码的语义空间与视觉空间一起。我们称这种攻击方法生成对抗性多对象场景攻击（GAMA）。 GAMA展示了剪辑模型作为攻击者的工具的实用性，以训练可强大的扰动发电机为多对象场景。使用联合图像文本功能来训练发电机，我们表明GAMA可以在各种攻击环境中制作有效的可转移扰动，以欺骗受害者分类器。例如，GAMA触发的错误分类比在黑框设置中的最新生成方法高出约16％，在黑框设置中，分类器体系结构和攻击者的数据分布都与受害者不同。我们的代码将很快公开提供。

将用户搜索查询与广告商实时竞标相关的关键字匹配是赞助搜索中的一个至关重要问题。在文献中，已经探索了两种广泛的方法来解决此问题：（i）在共享空间中学习查询和出价关键字的密集检索（DR），以及（ii）自然语言生成（NLG） - 学会直接生成给定查询的投标关键字。在这项工作中，我们首先对这两种方法进行了实证研究，并表明它们提供了添加剂的补充优势。特别是，从NLG检索到的很大一部分的关键字尚未由DR和反之亦然。然后，我们证明有可能将这两种方法的优势有效地结合在一个模型中。具体而言，我们提出了心脏：一种新型的多任务融合框架，在该框架中，我们共同优化共享编码器以同时执行DR和非自动性NLG。通过对30多个跨越20多种语言的搜索查询进行的广泛实验，我们表明，与使用相同的GPU计算的基线方法相比，心脏检索高质量的出价关键字40.3％。我们还证明，在单个心脏模型上推断与在两种不同的DR和NLG基线模型上推断为2倍计算一样好。此外，我们表明，接受心脏目标训练的DR模型要比接受标准对比度损失功能的训练的模型要好得多。最后，我们表明我们的心目标可以用于除赞助搜索并实现显着绩效提高以外的短文本检索任务。