异常和异常值检测是机器学习中的长期问题。在某些情况下,异常检测容易,例如当从诸如高斯的良好特征的分布中抽出数据时。但是,当数据占据高维空间时,异常检测变得更加困难。我们呈现蛤蜊(聚类学习近似歧管),是任何度量空间中的歧管映射技术。 CLAM以快速分层聚类技术开始,然后根据使用多个几何和拓扑功能所选择的重叠群集,从群集树中引导图表。使用这些图形,我们实现了Chaoda(群集分层异常和异常值检测算法),探索了图形的各种属性及其组成集群以查找异常值。 Chaoda采用了一种基于培训数据集的转移学习形式,并将这些知识应用于不同基数,维度和域的单独测试集。在24个公开可用的数据集上,我们将Chaoda(按衡量ROC AUC)与各种最先进的无监督异常检测算法进行比较。六个数据集用于培训。 Chaoda优于16个剩余的18个数据集的其他方法。 CLAM和Chaoda规模大,高维“大数据”异常检测问题,并贯穿数据集和距离函数。克拉姆和Chaoda的源代码在github上自由地提供https://github.com/uri-abd/clam。
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语言模型既展示了定量的改进,又展示了新的定性功能,随着规模的增加。尽管它们具有潜在的变革性影响,但这些新能力的特征却很差。为了为未来的研究提供信息,为破坏性的新模型能力做准备,并改善社会有害的效果,至关重要的是,我们必须了解目前和近乎未来的能力和语言模型的局限性。为了应对这一挑战,我们介绍了超越模仿游戏基准(Big Bench)。 Big Bench目前由204个任务组成,由132家机构的442位作者贡献。任务主题是多样的,从语言学,儿童发展,数学,常识性推理,生物学,物理学,社会偏见,软件开发等等。 Big-Bench专注于被认为超出当前语言模型的功能的任务。我们评估了OpenAI的GPT型号,Google内部密集变压器体系结构和大型基础上的开关稀疏变压器的行为,跨越了数百万到数十亿个参数。此外,一个人类专家评估者团队执行了所有任务,以提供强大的基准。研究结果包括:模型性能和校准都随规模改善,但绝对的术语(以及与评估者的性能相比);在模型类中的性能非常相似,尽管带有稀疏性。逐渐和预测的任务通常涉及大量知识或记忆成分,而在临界规模上表现出“突破性”行为的任务通常涉及多个步骤或组成部分或脆性指标;社交偏见通常会随着含糊不清的环境而随着规模而增加,但这可以通过提示来改善。
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大型语言模型已被证明可以使用少量学习来实现各种自然语言任务的出色表现,这大大减少了将模型调整到特定应用程序所需的特定任务培训示例的数量。为了进一步了解量表对少量学习的影响,我们培训了一个5400亿个参数,密集激活的变压器语言模型,我们称之为“途径”语言模型棕榈。我们使用Pathways在6144 TPU V4芯片上训练了Palm,这是一种新的ML系统,可在多个TPU POD上进行高效的训练。我们通过在数百种语言理解和产生基准的基准方面实现最先进的学习结果来证明扩展的持续好处。在这些任务中,Palm 540B实现了突破性的表现,在一系列多步推理任务上表现出色,超过了最新的最新表现,并且在最近发布的Big Benchmark上表现优于平均人类表现。大量的大型基础任务显示出与模型量表的不连续改进,这意味着当我们扩展到最大模型时,性能急剧增加。 Palm在多语言任务和源代码生成方面也具有很强的功能,我们在各种基准测试中证明了这一点。我们还提供了有关偏见和毒性的全面分析,并研究了训练数据记忆的程度,相对于模型量表。最后,我们讨论与大语言模型有关的道德考虑,并讨论潜在的缓解策略。
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神经网络的越来越大的规模及其越来越多的应用空间对更高的能量和记忆有效的人工智能特定硬件产生了需求。 venues为了缓解主要问题,von neumann瓶颈,包括内存和近记忆架构,以及算法方法。在这里,我们利用磁隧道结(MTJ)的低功耗和固有的二进制操作来展示基于MTJ的无源阵列的神经网络硬件推断。通常,由于设备到装置的变化,写入误差,寄生电阻和非前沿,在性能下将训练的网络模型转移到推动的硬件。为了量化这些硬件现实的效果,我们将300个唯一重量矩阵解决方案的23个唯一的重量矩阵解决方案进行分类,以分类葡萄酒数据集,用于分类准确性和写真保真度。尽管设备不完美,我们可以实现高达95.3%的软件等效精度,并在15 x 15 MTJ阵列中正确调整具有一系列设备尺寸的阵列。此调谐过程的成功表明,需要新的指标来表征混合信号硬件中再现的网络的性能和质量。
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强化学习目睹了最近在量子编程中的各种任务中的应用。基本的假设是这些任务可以建模为马尔可夫决策过程(MDP)。在这里,我们通过探索量子编程中的两个基本任务的后果来研究该假设的可行性:状态制备和门编译。通过形成离散的MDP,专门针对单量的情况(无论有没有噪声),我们可以通过策略迭代准确地为最佳策略求解。我们找到与最短门序列相对应的最佳路径,以准备状态或编译门,直至某些目标精度。例如,我们发现$ h $和$ t $门的序列长达$ 11 $生产$ \ sim 99 \%$ $ fidelity表格$(ht)^{n} | 0 \ rangle $值高达$ n = 10^{10} $。在存在门噪声的情况下,我们演示了最佳政策如何适应嘈杂的门的影响,以实现更高的状态忠诚度。我们的工作表明,人们可以将离散,随机和马尔可夫的性质强加于连续,确定性和非马克维亚量子演化,并提供理论上的洞察力,以了解为什么可以成功地使用强化学习来找到量子编程中的最佳短门序列。
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The recent increase in public and academic interest in preserving biodiversity has led to the growth of the field of conservation technology. This field involves designing and constructing tools that utilize technology to aid in the conservation of wildlife. In this article, we will use case studies to demonstrate the importance of designing conservation tools with human-wildlife interaction in mind and provide a framework for creating successful tools. These case studies include a range of complexities, from simple cat collars to machine learning and game theory methodologies. Our goal is to introduce and inform current and future researchers in the field of conservation technology and provide references for educating the next generation of conservation technologists. Conservation technology not only has the potential to benefit biodiversity but also has broader impacts on fields such as sustainability and environmental protection. By using innovative technologies to address conservation challenges, we can find more effective and efficient solutions to protect and preserve our planet's resources.
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We present the interpretable meta neural ordinary differential equation (iMODE) method to rapidly learn generalizable (i.e., not parameter-specific) dynamics from trajectories of multiple dynamical systems that vary in their physical parameters. The iMODE method learns meta-knowledge, the functional variations of the force field of dynamical system instances without knowing the physical parameters, by adopting a bi-level optimization framework: an outer level capturing the common force field form among studied dynamical system instances and an inner level adapting to individual system instances. A priori physical knowledge can be conveniently embedded in the neural network architecture as inductive bias, such as conservative force field and Euclidean symmetry. With the learned meta-knowledge, iMODE can model an unseen system within seconds, and inversely reveal knowledge on the physical parameters of a system, or as a Neural Gauge to "measure" the physical parameters of an unseen system with observed trajectories. We test the validity of the iMODE method on bistable, double pendulum, Van der Pol, Slinky, and reaction-diffusion systems.
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While the brain connectivity network can inform the understanding and diagnosis of developmental dyslexia, its cause-effect relationships have not yet enough been examined. Employing electroencephalography signals and band-limited white noise stimulus at 4.8 Hz (prosodic-syllabic frequency), we measure the phase Granger causalities among channels to identify differences between dyslexic learners and controls, thereby proposing a method to calculate directional connectivity. As causal relationships run in both directions, we explore three scenarios, namely channels' activity as sources, as sinks, and in total. Our proposed method can be used for both classification and exploratory analysis. In all scenarios, we find confirmation of the established right-lateralized Theta sampling network anomaly, in line with the temporal sampling framework's assumption of oscillatory differences in the Theta and Gamma bands. Further, we show that this anomaly primarily occurs in the causal relationships of channels acting as sinks, where it is significantly more pronounced than when only total activity is observed. In the sink scenario, our classifier obtains 0.84 and 0.88 accuracy and 0.87 and 0.93 AUC for the Theta and Gamma bands, respectively.
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Variational autoencoders model high-dimensional data by positing low-dimensional latent variables that are mapped through a flexible distribution parametrized by a neural network. Unfortunately, variational autoencoders often suffer from posterior collapse: the posterior of the latent variables is equal to its prior, rendering the variational autoencoder useless as a means to produce meaningful representations. Existing approaches to posterior collapse often attribute it to the use of neural networks or optimization issues due to variational approximation. In this paper, we consider posterior collapse as a problem of latent variable non-identifiability. We prove that the posterior collapses if and only if the latent variables are non-identifiable in the generative model. This fact implies that posterior collapse is not a phenomenon specific to the use of flexible distributions or approximate inference. Rather, it can occur in classical probabilistic models even with exact inference, which we also demonstrate. Based on these results, we propose a class of latent-identifiable variational autoencoders, deep generative models which enforce identifiability without sacrificing flexibility. This model class resolves the problem of latent variable non-identifiability by leveraging bijective Brenier maps and parameterizing them with input convex neural networks, without special variational inference objectives or optimization tricks. Across synthetic and real datasets, latent-identifiable variational autoencoders outperform existing methods in mitigating posterior collapse and providing meaningful representations of the data.
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There are multiple scales of abstraction from which we can describe the same image, depending on whether we are focusing on fine-grained details or a more global attribute of the image. In brain mapping, learning to automatically parse images to build representations of both small-scale features (e.g., the presence of cells or blood vessels) and global properties of an image (e.g., which brain region the image comes from) is a crucial and open challenge. However, most existing datasets and benchmarks for neuroanatomy consider only a single downstream task at a time. To bridge this gap, we introduce a new dataset, annotations, and multiple downstream tasks that provide diverse ways to readout information about brain structure and architecture from the same image. Our multi-task neuroimaging benchmark (MTNeuro) is built on volumetric, micrometer-resolution X-ray microtomography images spanning a large thalamocortical section of mouse brain, encompassing multiple cortical and subcortical regions. We generated a number of different prediction challenges and evaluated several supervised and self-supervised models for brain-region prediction and pixel-level semantic segmentation of microstructures. Our experiments not only highlight the rich heterogeneity of this dataset, but also provide insights into how self-supervised approaches can be used to learn representations that capture multiple attributes of a single image and perform well on a variety of downstream tasks. Datasets, code, and pre-trained baseline models are provided at: https://mtneuro.github.io/ .
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