Managing novelty in perception-based human activity recognition (HAR) is critical in realistic settings to improve task performance over time and ensure solution generalization outside of prior seen samples. Novelty manifests in HAR as unseen samples, activities, objects, environments, and sensor changes, among other ways. Novelty may be task-relevant, such as a new class or new features, or task-irrelevant resulting in nuisance novelty, such as never before seen noise, blur, or distorted video recordings. To perform HAR optimally, algorithmic solutions must be tolerant to nuisance novelty, and learn over time in the face of novelty. This paper 1) formalizes the definition of novelty in HAR building upon the prior definition of novelty in classification tasks, 2) proposes an incremental open world learning (OWL) protocol and applies it to the Kinetics datasets to generate a new benchmark KOWL-718, 3) analyzes the performance of current state-of-the-art HAR models when novelty is introduced over time, 4) provides a containerized and packaged pipeline for reproducing the OWL protocol and for modifying for any future updates to Kinetics. The experimental analysis includes an ablation study of how the different models perform under various conditions as annotated by Kinetics-AVA. The protocol as an algorithm for reproducing experiments using the KOWL-718 benchmark will be publicly released with code and containers at https://github.com/prijatelj/human-activity-recognition-in-an-open-world. The code may be used to analyze different annotations and subsets of the Kinetics datasets in an incremental open world fashion, as well as be extended as further updates to Kinetics are released.

人类识别对象何时已知或当前新颖的能力胜过所有开放式识别算法。通过心理学视觉心理物理学的方法和过程来衡量的人类感知可以为计算机视觉中的视觉识别任务中的新颖性提供附加的数据流。例如，人类受试者的测量反应时间可以提供有关是否可能与新颖的样本相混淆的洞察力。在这项工作中，我们设计并进行了大规模的行为实验，该实验收集了超过200,000种与物体识别相关的人类反应时间测量。收集的数据指示的反应时间在样本级别的对象之间有意义地变化。因此，我们设计了一种新的心理物理损失函数，该函数在深网中与人类行为保持一致性，该函数在不同图像中显示出可变的反应时间。与生物学愿景一样，这种方法使我们能够在标记有限的培训数据的制度中实现良好的开放式识别性能。通过使用来自ImageNet的数据的实验，当训练具有这种新配方的多尺度登记材料时，可以观察到显着改善：经过损失功能训练的模型可显着提高TOP-1验证精度7％，对已知样品的TOP-1测试准确性提高18％ ，以及未知样品的TOP-1测试精度33％。我们将我们的方法与文献中的10种开放式识别方法进行了比较，这些方法在多个指标上的表现都优于。

在本文中，我们分析了面部图像中基本身份的基本3D形状如何扭曲其整体外观，尤其是从深面识别的角度来看。正如在流行的训练数据增强方案中所做的那样，我们以随机选择或最合适的3D面部模型的形式渲染真实和合成的面部图像，以产生基本身份的新视图。我们比较了这些图像产生的深度特征，以评估这些渲染引入原始身份的扰动。我们以各种程度的面部偏航进行了这种分析，基本身份的性别和种族各不相同。此外，我们调查在这些渲染图像中添加某种形式的上下文和背景像素，当用作训练数据时，进一步改善了面部识别模型的下游性能。我们的实验证明了面部形状在准确的面部匹配中的重要性，并基于上下文数据对网络训练的重要性。

{g} {ustav} Fechner 1860年的心理物理学描述，即对其刺激的感觉的测量，被广泛认为是现代心理科学的出现。在心理物理学中，研究人员的参数会改变刺激的某些方面，并衡量人类受试者对该刺激的经历的变化；这样做可以深入了解感觉与唤起它的物理输入之间的关系。这种方法在感知域中大量使用，包括信号检测，阈值测量和理想的观察者分析。像视觉科学这样的科学领域始终依靠心理物理学的方法和程序，但是现在，机器学习研究人员对它们的越来越多，通过在生物学和人工感知之间扩大重叠\ cite \ cite {rojas2011automation {scheireratom，scheirer2014Perceptial2014Perceptual，Escalera2014ChaleAr2014Chalearearearearearnnag，Zhangy2018Agic， grieggs2021measuring}。由行为测量所指导的机器感知，而不是仅限于任意分配人类标签的指导，具有为人工智能进一步进步的巨大潜力。

Monumental advancements in artificial intelligence (AI) have lured the interest of doctors, lenders, judges, and other professionals. While these high-stakes decision-makers are optimistic about the technology, those familiar with AI systems are wary about the lack of transparency of its decision-making processes. Perturbation-based post hoc explainers offer a model agnostic means of interpreting these systems while only requiring query-level access. However, recent work demonstrates that these explainers can be fooled adversarially. This discovery has adverse implications for auditors, regulators, and other sentinels. With this in mind, several natural questions arise - how can we audit these black box systems? And how can we ascertain that the auditee is complying with the audit in good faith? In this work, we rigorously formalize this problem and devise a defense against adversarial attacks on perturbation-based explainers. We propose algorithms for the detection (CAD-Detect) and defense (CAD-Defend) of these attacks, which are aided by our novel conditional anomaly detection approach, KNN-CAD. We demonstrate that our approach successfully detects whether a black box system adversarially conceals its decision-making process and mitigates the adversarial attack on real-world data for the prevalent explainers, LIME and SHAP.

综合产生的内容的广泛扩散是一种需要紧急对策的严重威胁。合成含量的产生不限于多媒体数据，如视频，照片或音频序列，但涵盖了可以包括生物图像的显着大面积，例如西幕和微观图像。在本文中，我们专注于检测综合生成的西幕图像。生物医学文献在很大程度上探讨了西部污染图像，已经表明了如何通过目视检查或标准取证检测器轻松地伪造这些图像。为了克服缺乏公开可用的数据集，我们创建了一个包含超过14k原始的西幕图像和18K合成的Western-Blot图像的新数据集，由三种不同的最先进的生成方法产生。然后，我们调查不同的策略来检测合成的Western印迹，探索二进制分类方法以及单级探测器。在这两种情况下，我们从不利用培训阶段的合成纤维图像。所达到的结果表明，即使在这些科学图像的合成版本未优化利用检测器，综合生成的西幕图像也可以具有良好的精度。

面部合成的进步已经提出了关于合成面的欺骗性使用的警报。合成综合性可以有效地用于欺骗人类观察者吗？在本文中，我们介绍了使用不同策略产生的合成面的人类感知的研究，包括基于最先进的深学的GaN模型。这是第一次严格研究从心理学的实验技术接地的合成面代发电技术的有效性研究。我们回答了重要的问题，如GaN的频率和更传统的图像处理的技术混淆人类观察者，并且在综合性脸部图像中有细微的线索，导致人类将其视为假冒，而无需寻找明显的线索还为了回答这些问题，我们进行了一系列大规模众群行为实验，具有不同的面膜。结果表明，人类无法在几个不同的情况下区分真实面的合成面。这一发现对面部图像呈现给人类用户的许多不同应用具有严重影响。

Models of sensory processing and learning in the cortex need to efficiently assign credit to synapses in all areas. In deep learning, a known solution is error backpropagation, which however requires biologically implausible weight transport from feed-forward to feedback paths. We introduce Phaseless Alignment Learning (PAL), a bio-plausible method to learn efficient feedback weights in layered cortical hierarchies. This is achieved by exploiting the noise naturally found in biophysical systems as an additional carrier of information. In our dynamical system, all weights are learned simultaneously with always-on plasticity and using only information locally available to the synapses. Our method is completely phase-free (no forward and backward passes or phased learning) and allows for efficient error propagation across multi-layer cortical hierarchies, while maintaining biologically plausible signal transport and learning. Our method is applicable to a wide class of models and improves on previously known biologically plausible ways of credit assignment: compared to random synaptic feedback, it can solve complex tasks with less neurons and learn more useful latent representations. We demonstrate this on various classification tasks using a cortical microcircuit model with prospective coding.

Despite the impact of psychiatric disorders on clinical health, early-stage diagnosis remains a challenge. Machine learning studies have shown that classifiers tend to be overly narrow in the diagnosis prediction task. The overlap between conditions leads to high heterogeneity among participants that is not adequately captured by classification models. To address this issue, normative approaches have surged as an alternative method. By using a generative model to learn the distribution of healthy brain data patterns, we can identify the presence of pathologies as deviations or outliers from the distribution learned by the model. In particular, deep generative models showed great results as normative models to identify neurological lesions in the brain. However, unlike most neurological lesions, psychiatric disorders present subtle changes widespread in several brain regions, making these alterations challenging to identify. In this work, we evaluate the performance of transformer-based normative models to detect subtle brain changes expressed in adolescents and young adults. We trained our model on 3D MRI scans of neurotypical individuals (N=1,765). Then, we obtained the likelihood of neurotypical controls and psychiatric patients with early-stage schizophrenia from an independent dataset (N=93) from the Human Connectome Project. Using the predicted likelihood of the scans as a proxy for a normative score, we obtained an AUROC of 0.82 when assessing the difference between controls and individuals with early-stage schizophrenia. Our approach surpassed recent normative methods based on brain age and Gaussian Process, showing the promising use of deep generative models to help in individualised analyses.

Whole slide images (WSI) are microscopy images of stained tissue slides routinely prepared for diagnosis and treatment selection in medical practice. WSI are very large (gigapixel size) and complex (made of up to millions of cells). The current state-of-the-art (SoTA) approach to classify WSI subdivides them into tiles, encodes them by pre-trained networks and applies Multiple Instance Learning (MIL) to train for specific downstream tasks. However, annotated datasets are often small, typically a few hundred to a few thousand WSI, which may cause overfitting and underperforming models. Conversely, the number of unannotated WSI is ever increasing, with datasets of tens of thousands (soon to be millions) of images available. While it has been previously proposed to use these unannotated data to identify suitable tile representations by self-supervised learning (SSL), downstream classification tasks still require full supervision because parts of the MIL architecture is not trained during tile level SSL pre-training. Here, we propose a strategy of slide level SSL to leverage the large number of WSI without annotations to infer powerful slide representations. Applying our method to The Cancer-Genome Atlas, one of the most widely used data resources in cancer research (16 TB image data), we are able to downsize the dataset to 23 MB without any loss in predictive power: we show that a linear classifier trained on top of these embeddings maintains or improves previous SoTA performances on various benchmark WSI classification tasks. Finally, we observe that training a classifier on these representations with tiny datasets (e.g. 50 slides) improved performances over SoTA by an average of +6.3 AUC points over all downstream tasks.