机器教学(MT)是一个互动过程,其中人和机器与训练机器学习模型(ML)的目标相互作用。人类老师交流了他们的任务专业知识,机器学生收集了所需的数据和知识以产生ML模型。 MT系统的开发是共同最大程度地减少教学和学习者错误率的时间。 MT系统中人类互动的设计不仅会影响教学效率,而且通过影响教学质量来间接影响ML的性能。在本文中,我们以先前的工作为基础,在该工作中,我们提出了一个MT框架,其中包括三个组成部分,即教学界面,机器学习者和知识基础,并专注于实现教学涉及的人类互动设计界面。我们概述了从ML任务开始开发MT系统时需要解决的设计决策。该论文遵循苏格拉底式方法,需要在一个好奇的学生和智者老师之间进行对话。
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深度学习的成功使得能够在需要多模式任务中的进步,这些任务需要非普通融合多个输入域。尽管多式联运模型在许多问题中表现出潜力,但它们的复杂性增加使它们更容易攻击。后门(或特洛伊木马)攻击是一类安全漏洞,其中攻击者将恶意秘密行为嵌入到网络(例如目标错误分类)中,当攻击者指定的触发添加到输入时被激活。在这项工作中,我们表明多模态网络容易受到我们称之为双关键多模式后域的新型攻击。该攻击利用最先进的网络使用的复杂融合机制来嵌入有效和隐秘的后门。该建议的攻击而不是使用单个触发器,而不是使用单个触发器在每个输入模件中嵌入触发器,并仅在存在两种触发时激活恶意行为。我们对具有多个体系结构和视觉功能底座的视觉问题应答(VQA)任务进行了广泛的研究。在VQA模型中嵌入后门的一项重大挑战是,大多数模型都使用从固定的预磨削物体检测器中提取的可视化特征。这对攻击者有挑战性,因为探测器完全扭曲或忽略视觉触发,这导致了后域在语言触发上过于依赖的模型。我们通过提出为预磨料对象探测器设计的可视触发优化策略来解决这个问题。通过这种方法,我们创建双关键的返回室,超过98%的攻击成功率,同时只毒害了1%的培训数据。最后,我们发布了Trojvqa,大量的干净和特洛伊木马VQA模型,以实现对多模式后域的捍卫的研究。
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Large language models (LLMs) have demonstrated impressive capabilities in natural language understanding and generation, but the quality bar for medical and clinical applications is high. Today, attempts to assess models' clinical knowledge typically rely on automated evaluations on limited benchmarks. There is no standard to evaluate model predictions and reasoning across a breadth of tasks. To address this, we present MultiMedQA, a benchmark combining six existing open question answering datasets spanning professional medical exams, research, and consumer queries; and HealthSearchQA, a new free-response dataset of medical questions searched online. We propose a framework for human evaluation of model answers along multiple axes including factuality, precision, possible harm, and bias. In addition, we evaluate PaLM (a 540-billion parameter LLM) and its instruction-tuned variant, Flan-PaLM, on MultiMedQA. Using a combination of prompting strategies, Flan-PaLM achieves state-of-the-art accuracy on every MultiMedQA multiple-choice dataset (MedQA, MedMCQA, PubMedQA, MMLU clinical topics), including 67.6% accuracy on MedQA (US Medical License Exam questions), surpassing prior state-of-the-art by over 17%. However, human evaluation reveals key gaps in Flan-PaLM responses. To resolve this we introduce instruction prompt tuning, a parameter-efficient approach for aligning LLMs to new domains using a few exemplars. The resulting model, Med-PaLM, performs encouragingly, but remains inferior to clinicians. We show that comprehension, recall of knowledge, and medical reasoning improve with model scale and instruction prompt tuning, suggesting the potential utility of LLMs in medicine. Our human evaluations reveal important limitations of today's models, reinforcing the importance of both evaluation frameworks and method development in creating safe, helpful LLM models for clinical applications.
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We study the sample complexity of reducing reinforcement learning to a sequence of empirical risk minimization problems over the policy space. Such reductions-based algorithms exhibit local convergence in the function space, as opposed to the parameter space for policy gradient algorithms, and thus are unaffected by the possibly non-linear or discontinuous parameterization of the policy class. We propose a variance-reduced variant of Conservative Policy Iteration that improves the sample complexity of producing a $\varepsilon$-functional local optimum from $O(\varepsilon^{-4})$ to $O(\varepsilon^{-3})$. Under state-coverage and policy-completeness assumptions, the algorithm enjoys $\varepsilon$-global optimality after sampling $O(\varepsilon^{-2})$ times, improving upon the previously established $O(\varepsilon^{-3})$ sample requirement.
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This paper proposes a novel controller framework that provides trajectory tracking for an Aerial Manipulator (AM) while ensuring the safe operation of the system under unknown bounded disturbances. The AM considered here is a 2-DOF (degrees-of-freedom) manipulator rigidly attached to a UAV. Our proposed controller structure follows the conventional inner loop PID control for attitude dynamics and an outer loop controller for tracking a reference trajectory. The outer loop control is based on the Model Predictive Control (MPC) with constraints derived using the Barrier Lyapunov Function (BLF) for the safe operation of the AM. BLF-based constraints are proposed for two objectives, viz. 1) To avoid the AM from colliding with static obstacles like a rectangular wall, and 2) To maintain the end effector of the manipulator within the desired workspace. The proposed BLF ensures that the above-mentioned objectives are satisfied even in the presence of unknown bounded disturbances. The capabilities of the proposed controller are demonstrated through high-fidelity non-linear simulations with parameters derived from a real laboratory scale AM. We compare the performance of our controller with other state-of-the-art MPC controllers for AM.
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Virtual Product placement(VPP) is the advertising technique of digitally placing a branded object into the scene of a movie or TV show. This type of advertising provides the ability for brands to reach consumers without interrupting the viewing experience with a commercial break, as the products are seen in the background or as props. Despite this being a billion-dollar industry, ad rendering technique is currently executed at post production stage, manually either with the help of VFx artists or through semi-automated solutions. In this paper, we demonstrate a fully automated framework to digitally place 2-D ads in linear TV cooking shows captured using single-view camera with small camera movements. Without access to full video or production camera configuration, this framework performs the following tasks (i) identifying empty space for 2-D ad placement (ii) kitchen scene understanding (iii) occlusion handling (iv) ambient lighting and (v) ad tracking.
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The use of emojis affords a visual modality to, often private, textual communication. The task of predicting emojis however provides a challenge for machine learning as emoji use tends to cluster into the frequently used and the rarely used emojis. Much of the machine learning research on emoji use has focused on high resource languages and has conceptualised the task of predicting emojis around traditional server-side machine learning approaches. However, traditional machine learning approaches for private communication can introduce privacy concerns, as these approaches require all data to be transmitted to a central storage. In this paper, we seek to address the dual concerns of emphasising high resource languages for emoji prediction and risking the privacy of people's data. We introduce a new dataset of $118$k tweets (augmented from $25$k unique tweets) for emoji prediction in Hindi, and propose a modification to the federated learning algorithm, CausalFedGSD, which aims to strike a balance between model performance and user privacy. We show that our approach obtains comparative scores with more complex centralised models while reducing the amount of data required to optimise the models and minimising risks to user privacy.
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In light of unprecedented increases in the popularity of the internet and social media, comment moderation has never been a more relevant task. Semi-automated comment moderation systems greatly aid human moderators by either automatically classifying the examples or allowing the moderators to prioritize which comments to consider first. However, the concept of inappropriate content is often subjective, and such content can be conveyed in many subtle and indirect ways. In this work, we propose CoRAL -- a language and culturally aware Croatian Abusive dataset covering phenomena of implicitness and reliance on local and global context. We show experimentally that current models degrade when comments are not explicit and further degrade when language skill and context knowledge are required to interpret the comment.
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室内运动计划的重点是解决通过混乱环境导航代理的问题。迄今为止,在该领域已经完成了很多工作,但是这些方法通常无法找到计算廉价的在线路径计划和路径最佳之间的最佳平衡。除此之外,这些作品通常证明是单一启动单目标世界的最佳性。为了应对这些挑战,我们为在未知室内环境中进行导航的多个路径路径计划者和控制器堆栈,在该环境中,路点将目标与机器人必须在达到目标之前必须穿越的中介点一起。我们的方法利用全球规划师(在任何瞬间找到下一个最佳航路点),本地规划师(计划通往特定航路点的路径)以及自适应模型预测性控制策略(用于强大的系统控制和更快的操作) 。我们在一组随机生成的障碍图,中间航路点和起始目标对上评估了算法,结果表明计算成本显着降低,具有高度准确性和可靠的控制。
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至于其他形式的AI,最近已经对不同用户同伙的性能差异进行了研究。在语音识别方面实现公平性的一种方法是(1)确定遭受低标准表现的说话者队列,以及(2)采取针对发现同类的公平性缓解措施。在本文中,我们使用产品规模的AI助手语音识别系统的数据报告了发现和缓解性能差异的初步发现。我们将基于地理和人口统计学信息的队列发现与一种更可扩展的方法进行比较,该方法将使用扬声器嵌入技术分组没有人类标签的说话者。为了缓解公平性,我们发现对代表性不足的队列的过度采样,以及通过其他输入变量对扬声器队列的建模,从而减少了表现和底部性能队列之间的差距,而不会降低整体识别精度。
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