我们研究了基于消费者的决策积极学习非参数选择模型的问题。我们提出一个负面结果，表明这种选择模型可能无法识别。为了克服可识别性问题，我们介绍了选择模型的有向无环图（DAG）表示，从某种意义上说，该模型可以捕获有关选择模型的更多信息，从而可以从理论上识别信息。然后，我们考虑在主动学习环境中学习与此DAG表示的近似的问题。我们设计了一种有效的主动学习算法，以估计非参数选择模型的DAG表示，该模型在多项式时间内运行时，当随机均匀地绘制频繁排名。我们的算法通过主动和反复提供各种项目并观察所选项目来了解最受欢迎的频繁偏好项目的分布。我们表明，与相应的非活动学习估计算法相比，我们的算法可以更好地恢复有关消费者偏好的合成和公开数据集的一组频繁偏好。这证明了我们的算法和主动学习方法的价值。

在随着时间变化的组合环境中的在线决策激励，我们研究了将离线算法转换为其在线对应物的问题。我们专注于使用贪婪算法对局部错误的贪婪算法进行恒定因子近似的离线组合问题。对于此类问题，我们提供了一个通用框架，该框架可有效地将稳健的贪婪算法转换为使用Blackwell的易近算法。我们证明，在完整信息设置下，由此产生的在线算法具有$ O（\ sqrt {t}）$（近似）遗憾。我们进一步介绍了Blackwell易接近性的强盗扩展，我们称之为Bandit Blackwell的可接近性。我们利用这一概念将贪婪的稳健离线算法转变为匪（t^{2/3}）$（近似）$（近似）的遗憾。展示了我们框架的灵活性，我们将脱机之间的转换应用于收入管理，市场设计和在线优化的几个问题，包括在线平台中的产品排名优化，拍卖中的储备价格优化以及supperular tossodular最大化。 。我们还将还原扩展到连续优化的类似贪婪的一阶方法，例如用于最大化连续强的DR单调下调功能，这些功能受到凸约束的约束。我们表明，当应用于这些应用程序时，我们的转型会导致新的后悔界限或改善当前已知界限。我们通过为我们的两个应用进行数值模拟来补充我们的理论研究，在这两种应用中，我们都观察到，转换的数值性能在实际情况下优于理论保证。

The lack of standardization is a prominent issue in magnetic resonance (MR) imaging. This often causes undesired contrast variations due to differences in hardware and acquisition parameters. In recent years, MR harmonization using image synthesis with disentanglement has been proposed to compensate for the undesired contrast variations. Despite the success of existing methods, we argue that three major improvements can be made. First, most existing methods are built upon the assumption that multi-contrast MR images of the same subject share the same anatomy. This assumption is questionable since different MR contrasts are specialized to highlight different anatomical features. Second, these methods often require a fixed set of MR contrasts for training (e.g., both Tw-weighted and T2-weighted images must be available), which limits their applicability. Third, existing methods generally are sensitive to imaging artifacts. In this paper, we present a novel approach, Harmonization with Attention-based Contrast, Anatomy, and Artifact Awareness (HACA3), to address these three issues. We first propose an anatomy fusion module that enables HACA3 to respect the anatomical differences between MR contrasts. HACA3 is also robust to imaging artifacts and can be trained and applied to any set of MR contrasts. Experiments show that HACA3 achieves state-of-the-art performance under multiple image quality metrics. We also demonstrate the applicability of HACA3 on downstream tasks with diverse MR datasets acquired from 21 sites with different field strengths, scanner platforms, and acquisition protocols.

Neural networks have revolutionized the area of artificial intelligence and introduced transformative applications to almost every scientific field and industry. However, this success comes at a great price; the energy requirements for training advanced models are unsustainable. One promising way to address this pressing issue is by developing low-energy neuromorphic hardware that directly supports the algorithm's requirements. The intrinsic non-volatility, non-linearity, and memory of spintronic devices make them appealing candidates for neuromorphic devices. Here we focus on the reservoir computing paradigm, a recurrent network with a simple training algorithm suitable for computation with spintronic devices since they can provide the properties of non-linearity and memory. We review technologies and methods for developing neuromorphic spintronic devices and conclude with critical open issues to address before such devices become widely used.

In the contemporary media landscape, with the vast and diverse supply of news, it is increasingly challenging to study such an enormous amount of items without a standardized framework. Although attempts have been made to organize and compare news items on the basis of news values, news genres receive little attention, especially the genres in a news consumer's perception. Yet, perceived news genres serve as an essential component in exploring how news has developed, as well as a precondition for understanding media effects. We approach this concept by conceptualizing and operationalizing a non-discrete framework for mapping news items in terms of genre cues. As a starting point, we propose a preliminary set of dimensions consisting of "factuality" and "formality". To automatically analyze a large amount of news items, we deliver two computational models for predicting news sentences in terms of the said two dimensions. Such predictions could then be used for locating news items within our framework. This proposed approach that positions news items upon a multidimensional grid helps in deepening our insight into the evolving nature of news genres.

Federated Deep Learning frameworks can be used strategically to monitor Land Use locally and infer environmental impacts globally. Distributed data from across the world would be needed to build a global model for Land Use classification. The need for a Federated approach in this application domain would be to avoid transfer of data from distributed locations and save network bandwidth to reduce communication cost. We use a Federated UNet model for Semantic Segmentation of satellite and street view images. The novelty of the proposed architecture is the integration of Knowledge Distillation to reduce communication cost and response time. The accuracy obtained was above 95% and we also brought in a significant model compression to over 17 times and 62 times for street View and satellite images respectively. Our proposed framework has the potential to be a game-changer in real-time tracking of climate change across the planet.

Mobile health (mHealth) technologies empower patients to adopt/maintain healthy behaviors in their daily lives, by providing interventions (e.g. push notifications) tailored to the user's needs. In these settings, without intervention, human decision making may be impaired (e.g. valuing near term pleasure over own long term goals). In this work, we formalize this relationship with a framework in which the user optimizes a (potentially impaired) Markov Decision Process (MDP) and the mHealth agent intervenes on the user's MDP parameters. We show that different types of impairments imply different types of optimal intervention. We also provide analytical and empirical explorations of these differences.

In this technical note, we introduce an improved variant of nearest neighbors for counterfactual inference in panel data settings where multiple units are assigned multiple treatments over multiple time points, each sampled with constant probabilities. We call this estimator a doubly robust nearest neighbor estimator and provide a high probability non-asymptotic error bound for the mean parameter corresponding to each unit at each time. Our guarantee shows that the doubly robust estimator provides a (near-)quadratic improvement in the error compared to nearest neighbor estimators analyzed in prior work for these settings.

深度学习已在许多神经影像应用中有效。但是，在许多情况下，捕获与小血管疾病有关的信息的成像序列的数量不足以支持数据驱动的技术。此外，基于队列的研究可能并不总是具有用于准确病变检测的最佳或必需成像序列。因此，有必要确定哪些成像序列对于准确检测至关重要。在这项研究中，我们旨在找到磁共振成像（MRI）序列的最佳组合，以深入基于学习的肿瘤周围空间（EPV）。为此，我们实施了一个有效的轻巧U-NET，适用于EPVS检测，并全面研究了来自易感加权成像（SWI），流体侵入的反转恢复（FLAIR），T1加权（T1W）和T2的不同信息组合 - 加权（T2W）MRI序列。我们得出的结论是，T2W MRI对于准确的EPV检测最为重要，并且在深神经网络中掺入SWI，FLAIR和T1W MRI可能会使精度的提高无关。

社交媒体的日益普及引起了人们对儿童在线安全的关注。未成年人与具有掠夺性意图的成年人之间的互动是一个特别严重的关注点。在线性修饰的研究通常依靠领域专家来手动注释对话，从而限制了规模和范围。在这项工作中，我们测试了良好的方法如何检测对话行为并取代专家的人类注释。在在线修饰的心理理论中，我们将$ 6772的$ 6772 $聊天消息标记为儿童性犯罪者以十一种掠夺性行为之一发送的聊天消息。我们训练字袋和自然语言推断模型来对每种行为进行分类，并表明，最佳性能模型以一致但不与人类注释的方式分类的方式对行为进行了分类。