Simulating physical network paths (e.g., Internet) is a cornerstone research problem in the emerging sub-field of AI-for-networking. We seek a model that generates end-to-end packet delay values in response to the time-varying load offered by a sender, which is typically a function of the previously output delays. The problem setting is unique, and renders the state-of-the-art text and time-series generative models inapplicable or ineffective. We formulate an ML problem at the intersection of dynamical systems, sequential decision making, and time-series modeling. We propose a novel grey-box approach to network simulation that embeds the semantics of physical network path in a new RNN-style model called RBU, providing the interpretability of standard network simulator tools, the power of neural models, the efficiency of SGD-based techniques for learning, and yielding promising results on synthetic and real-world network traces.
translated by 谷歌翻译
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.
translated by 谷歌翻译
The rapid growth of machine translation (MT) systems has necessitated comprehensive studies to meta-evaluate evaluation metrics being used, which enables a better selection of metrics that best reflect MT quality. Unfortunately, most of the research focuses on high-resource languages, mainly English, the observations for which may not always apply to other languages. Indian languages, having over a billion speakers, are linguistically different from English, and to date, there has not been a systematic study of evaluating MT systems from English into Indian languages. In this paper, we fill this gap by creating an MQM dataset consisting of 7000 fine-grained annotations, spanning 5 Indian languages and 7 MT systems, and use it to establish correlations between annotator scores and scores obtained using existing automatic metrics. Our results show that pre-trained metrics, such as COMET, have the highest correlations with annotator scores. Additionally, we find that the metrics do not adequately capture fluency-based errors in Indian languages, and there is a need to develop metrics focused on Indian languages. We hope that our dataset and analysis will help promote further research in this area.
translated by 谷歌翻译
我们研究了$ k $武装的决斗匪徒问题,这是传统的多武器匪徒问题的一种变体,其中以成对比较的形式获得了反馈。以前的学习算法专注于$ \ textit {完全自适应} $设置,在每次比较后,算法可以进行更新。 “批处理”决斗匪徒问题是由Web搜索排名和推荐系统等大规模应用程序激励的,在这种应用程序中执行顺序更新可能是不可行的。在这项工作中,我们要问:$ \ textit {是否只使用几个自适应回合有解决方案,该回合与$ k $ armed的决斗匪徒的最佳顺序算法的渐近后悔界限?} $? \ textit {在condorcet条件下} $,这是$ k $武装的决斗匪徒问题的标准设置。我们获得$ O(k^2 \ log^2(k)) + O(k \ log(t))$的渐近遗憾地平线。我们的遗憾界限几乎与在Condorcet条件下完全顺序环境中已知的最佳后悔界限相匹配。最后,在各种现实世界数据集的计算实验中,我们观察到使用$ o(\ log(t))$ rounds的算法与完全顺序的算法(使用$ t $ rounds)的性能几乎相同。
translated by 谷歌翻译
Natarajan维度是表征多级PAC可学习性的基本工具,将VAPNIK-CHERVONENKIS(VC)维度推广到从二进制到多类分类问题。本说明在某些功能类别的Natarajan维度上建立了上限,包括(i)多级决策树和随机森林,以及(ii)具有二进制,线性和relu激活的多级神经网络。这些结果可能与描述某些多级学习算法的性能有关。
translated by 谷歌翻译
前列腺活检和图像引导的治疗程序通常是在与磁共振图像(MRI)的超声指导下进行的。准确的图像融合依赖于超声图像上前列腺的准确分割。然而,超声图像中降低的信噪比和工件(例如,斑点和阴影)限制了自动前列腺分割技术的性能,并将这些方法推广到新的图像域是本质上很难的。在这项研究中,我们通过引入一种新型的2.5D深神经网络来解决这些挑战,用于超声图像上的前列腺分割。我们的方法通过组合有监督的域适应技术和知识蒸馏损失,解决了转移学习和填充方法的局限性(即,在更新模型权重时,在更新模型权重时的性能下降)。知识蒸馏损失允许保留先前学习的知识,并在新数据集上的模型填充后降低性能下降。此外,我们的方法依赖于注意模块,该模块认为模型特征定位信息以提高分割精度。我们对一个机构的764名受试者进行了培训,并仅使用后续机构中的十个受试者对我们的模型进行了审核。我们分析了方法在三个大型数据集上的性能,其中包括来自三个不同机构的2067名受试者。我们的方法达到了平均骰子相似性系数(骰子)为$ 94.0 \ pm0.03 $,而Hausdorff距离(HD95)为2.28 $ mm $,在第一机构的独立受试者中。此外,我们的模型在其他两个机构的研究中都很好地概括了(骰子:$ 91.0 \ pm0.03 $; hd95:3.7 $ mm $ and Dice:$ 82.0 \ pm0.03 $; hd95 $; hd95:7.1 $ mm $)。
translated by 谷歌翻译
我们考虑自适应 - 调节功能的最低成本覆盖率的问题,并提供4(ln Q+1) - approximation算法,其中Q是目标值。该结合几乎是最好的,因为该问题不能接受比LN Q更好的近似值(除非p = np)。我们的结果是该问题的第一个O(LN Q) - Approximation算法。以前,o(ln q)近似算法仅假设独立项目或单位成本项目是已知的。此外,我们的结果很容易扩展到想要同时覆盖多个自适应 - 调节函数的设置:我们获得了此概括的第一个近似算法。
translated by 谷歌翻译
给定有关消费者对不同分类的选择的数据,一个关键的挑战是开发描述和预测消费者选择行为的简约模型。一个这样的选择模型是边际分布模型,它仅需要替代方案随机实用程序的边际分布的规范,以解释选择数据。在本文中,我们开发了一组选择概率的精确表征,这些概率是通过边际分布模型在任何集合中始终如一地表示的。为了根据其实用程序的边际分布进行分组的可能性,我们表明(a)在多项式时间内可以验证选择概率数据的一致性,并且(b)找到最接近的拟合量可以减少解决混合的拟合。整数凸面程序。我们的结果表明,与随机效用模型相比,与多项式logit相比,边际分布模型提供了更好的代表力和更好的计算性能。
translated by 谷歌翻译
在这项工作中,我们证明了多种语的大规模序列到序列(SEQ2SEQ)模型,该模型是通过Denoising和因果语言建模(CLM)任务的混合物进行训练的,比仅解码器模型更有效地进行了效率的学习者在各种任务上。特别是,我们培训了一个名为Alexa教师模型(Alexatm 20b)的200亿个参数多语言SEQ2SEQ模型,并表明它在1-Shot摘要任务上实现了最先进的(SOTA)性能,超过了更大的540B PALM DOPODER模型。 Alexatm 20b还可以在1-Shot Machine翻译中实现SOTA,尤其是对于低资源语言,几乎所有语言对(阿拉伯语,英语,法语,德语,德语,印地语,意大利语,日语,以及flores-101数据集上的泰卢固语)。我们还显示了零拍设置,AlexATM 20B在SuperGlue和SqueadV2数据集上的表现优于GPT3(175B),并在XNLI,XCOPA,PAWS-X和XWINOGRAD等多语言任务上提供SOTA性能。总体而言,我们的结果为SEQ2SEQ模型提供了一个令人信服的案例,作为大型语言模型(LLM)培训的仅解码器模型的强大替代方法。
translated by 谷歌翻译
对新闻文章的政治偏见进行分类的传统方法未能产生准确的,可概括的结果。 CNN和DNN上的前提的现有网络缺乏识别和推断诸如单词选择,上下文和演示文稿之类的微妙指标的模型。在本文中,我们提出了一个网络体系结构,该网络体系结构在为文章分配偏见分类方面达到了人类水平的准确性。基础模型基于新型网格神经网络(MNN),该结构可实现网格中任何两个神经元之间的反馈和进发突触连接。 MNN ONTARE ONING六个网络配置,利用基于Bernoulli的随机采样,预训练的DNN和以C. exemans nematode建模的网络。该模型接受了从Allsides.com刮除的一千多篇文章的培训,这些文章被标记为表明政治偏见。然后使用适合反馈神经结构的遗传算法进化网络的参数。最后,最佳性能模型适用于美国的五个流行新闻来源,在为期五十天的试验中,以量化其展示的文章中的政治偏见。我们希望我们的项目能够刺激NLP任务的生物解决方案研究,并为公民提供准确的工具,以了解他们消耗的文章中微妙的偏见。
translated by 谷歌翻译