预测流感病毒引起的住院治疗对于公共卫生计划至关重要,因此医院可以为大量患者做好准备。在流感季节中实时使用了许多预测方法,并提交给疾病预防控制中心进行公共交流。预测模型范围从机械模型和自动回归模型到机器学习模型。我们假设我们可以通过使用多个机械模型生成潜在的轨迹并使用机器学习来学习如何将这些轨迹结合到改进的预测中,从而改善预测。我们提出了一种树木合奏模型设计,该设计利用基线模型Sikjalpha的各个预测指标来提高其性能。每个预测因子都是通过更改一组超参数来生成的。我们将为Flusight Challenge(2022)部署的前瞻性预测与所有其他提交的方法进行了比较。我们的方法是完全自动化的,不需要任何手动调整。我们证明,基于森林的随机方法能够根据平均绝对误差,覆盖范围和加权间隔得分来改善单个预测因子的预测。我们的方法根据平均绝对误差和基于当前季节所有每周提交的平均值(2022)的平均值来优于所有其他模型。随机森林(通过对树木的分析)的解释能力使我们能够深入了解其如何改善单个预测因子。
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Adequate strategizing of agents behaviors is essential to solving cooperative MARL problems. One intuitively beneficial yet uncommon method in this domain is predicting agents future behaviors and planning accordingly. Leveraging this point, we propose a two-level hierarchical architecture that combines a novel information-theoretic objective with a trajectory prediction model to learn a strategy. To this end, we introduce a latent policy that learns two types of latent strategies: individual $z_A$, and relational $z_R$ using a modified Graph Attention Network module to extract interaction features. We encourage each agent to behave according to the strategy by conditioning its local $Q$ functions on $z_A$, and we further equip agents with a shared $Q$ function that conditions on $z_R$. Additionally, we introduce two regularizers to allow predicted trajectories to be accurate and rewarding. Empirical results on Google Research Football (GRF) and StarCraft (SC) II micromanagement tasks show that our method establishes a new state of the art being, to the best of our knowledge, the first MARL algorithm to solve all super hard SC II scenarios as well as the GRF full game with a win rate higher than $95\%$, thus outperforming all existing methods. Videos and brief overview of the methods and results are available at: https://sites.google.com/view/hier-strats-marl/home.
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实现安全和强大的自主权是通往更广泛采用自动驾驶汽车技术的道路的关键瓶颈。这激发了超越外在指标,例如脱离接触之间的里程,并呼吁通过设计体现安全的方法。在本文中,我们解决了这一挑战的某些方面,重点是运动计划和预测问题。我们通过描述在自动驾驶堆栈中解决选定的子问题所采取的新方法的描述,在介绍五个之内采用的设计理念的过程中。这包括安全的设计计划,可解释以及可验证的预测以及对感知错误的建模,以在现实自主系统的测试管道中实现有效的SIM到现实和真实的SIM转移。
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自动驾驶汽车使用各种传感器和机器学习型号来预测周围道路使用者的行为。文献中的大多数机器学习模型都集中在定量误差指标上,例如均方根误差(RMSE),以学习和报告其模型的功能。对定量误差指标的关注倾向于忽略模型的更重要的行为方面,从而提出了这些模型是否真正预测类似人类行为的问题。因此,我们建议分析机器学习模型的输出,就像我们将在常规行为研究中分析人类数据一样。我们介绍定量指标,以证明在自然主义高速公路驾驶数据集中存在三种不同的行为现象:1)运动学依赖性谁通过合并点首次通过合并点2)巷道上的车道更改,可容纳坡道车辆3 )车辆通过高速公路上的车辆变化,以避免铅车冲突。然后,我们使用相同的指标分析了三个机器学习模型的行为。即使模型的RMSE值有所不同,所有模型都捕获了运动学依赖性的合并行为,但在不同程度上挣扎着捕获更细微的典型礼貌车道变更和高速公路车道的变化行为。此外,车道变化期间的碰撞厌恶分析表明,模型努力捕获人类驾驶的物理方面:在车辆之间留下足够的差距。因此,我们的分析强调了简单的定量指标不足,并且在分析人类驾驶预测的机器学习模型时需要更广泛的行为观点。
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基于方面的情感分析非常重要和应用,因为它能够识别文本中讨论的所有方面。但是,基于方面的情感分析将是最有效的,除了确定文本中讨论的所有方面外,它还可以识别其极性。大多数以前的方法都使用管道方法,即,它们首先识别各个方面,然后识别极性。此类方法不适合实际应用,因为它们可以导致模型错误。因此,在这项研究中,我们提出了一个基于卷积神经网络(CNN)的多任务学习模型,该模型可以同时检测方面类别并检测方面类别的极性。单独创建模型可能不会提供最佳的预测,并导致诸如偏见和高方差之类的错误。为了减少这些错误并提高模型预测的效率,将几种称为合奏学习的模型组合在一起可以提供更好的结果。因此,本文的主要目的是创建一个基于多任务深度卷积神经网络合奏的模型,以增强波斯评论中的情感分析。我们使用电影域中的波斯语数据集评估了提出的方法。 jacquard索引和锤损失措施用于评估开发模型的性能。结果表明,这种新方法提高了波斯语中情感分析模型的效率。
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Recent work has shown the benefits of synthetic data for use in computer vision, with applications ranging from autonomous driving to face landmark detection and reconstruction. There are a number of benefits of using synthetic data from privacy preservation and bias elimination to quality and feasibility of annotation. Generating human-centered synthetic data is a particular challenge in terms of realism and domain-gap, though recent work has shown that effective machine learning models can be trained using synthetic face data alone. We show that this can be extended to include the full body by building on the pipeline of Wood et al. to generate synthetic images of humans in their entirety, with ground-truth annotations for computer vision applications. In this report we describe how we construct a parametric model of the face and body, including articulated hands; our rendering pipeline to generate realistic images of humans based on this body model; an approach for training DNNs to regress a dense set of landmarks covering the entire body; and a method for fitting our body model to dense landmarks predicted from multiple views.
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To generate high quality rendering images for real time applications, it is often to trace only a few samples-per-pixel (spp) at a lower resolution and then supersample to the high resolution. Based on the observation that the rendered pixels at a low resolution are typically highly aliased, we present a novel method for neural supersampling based on ray tracing 1/4-spp samples at the high resolution. Our key insight is that the ray-traced samples at the target resolution are accurate and reliable, which makes the supersampling an interpolation problem. We present a mask-reinforced neural network to reconstruct and interpolate high-quality image sequences. First, a novel temporal accumulation network is introduced to compute the correlation between current and previous features to significantly improve their temporal stability. Then a reconstruct network based on a multi-scale U-Net with skip connections is adopted for reconstruction and generation of the desired high-resolution image. Experimental results and comparisons have shown that our proposed method can generate higher quality results of supersampling, without increasing the total number of ray-tracing samples, over current state-of-the-art methods.
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In this paper we explore the task of modeling (semi) structured object sequences; in particular we focus our attention on the problem of developing a structure-aware input representation for such sequences. In such sequences, we assume that each structured object is represented by a set of key-value pairs which encode the attributes of the structured object. Given a universe of keys, a sequence of structured objects can then be viewed as an evolution of the values for each key, over time. We encode and construct a sequential representation using the values for a particular key (Temporal Value Modeling - TVM) and then self-attend over the set of key-conditioned value sequences to a create a representation of the structured object sequence (Key Aggregation - KA). We pre-train and fine-tune the two components independently and present an innovative training schedule that interleaves the training of both modules with shared attention heads. We find that this iterative two part-training results in better performance than a unified network with hierarchical encoding as well as over, other methods that use a {\em record-view} representation of the sequence \cite{de2021transformers4rec} or a simple {\em flattened} representation of the sequence. We conduct experiments using real-world data to demonstrate the advantage of interleaving TVM-KA on multiple tasks and detailed ablation studies motivating our modeling choices. We find that our approach performs better than flattening sequence objects and also allows us to operate on significantly larger sequences than existing methods.
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In this chapter, we review and discuss the transformation of AI technology in HCI/UX work and assess how AI technology will change how we do the work. We first discuss how AI can be used to enhance the result of user research and design evaluation. We then discuss how AI technology can be used to enhance HCI/UX design. Finally, we discuss how AI-enabled capabilities can improve UX when users interact with computing systems, applications, and services.
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Deep neural networks (DNNs) are vulnerable to a class of attacks called "backdoor attacks", which create an association between a backdoor trigger and a target label the attacker is interested in exploiting. A backdoored DNN performs well on clean test images, yet persistently predicts an attacker-defined label for any sample in the presence of the backdoor trigger. Although backdoor attacks have been extensively studied in the image domain, there are very few works that explore such attacks in the video domain, and they tend to conclude that image backdoor attacks are less effective in the video domain. In this work, we revisit the traditional backdoor threat model and incorporate additional video-related aspects to that model. We show that poisoned-label image backdoor attacks could be extended temporally in two ways, statically and dynamically, leading to highly effective attacks in the video domain. In addition, we explore natural video backdoors to highlight the seriousness of this vulnerability in the video domain. And, for the first time, we study multi-modal (audiovisual) backdoor attacks against video action recognition models, where we show that attacking a single modality is enough for achieving a high attack success rate.
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