在本文中,我们提出了一种用于几个样本监督功能选择(FS)的新方法。我们的方法首先使用捕获多功能关联的内核来了解每个类的特征空间的歧视。然后,基于Riemannian几何形状,计算复合内核,从而提取了学习的特征关联之间的差异。最后,提出了基于光谱分析的FS分数。考虑多功能关联使我们的方法逐个设计。反过来,这允许提取特征基础的隐藏歧管,并避免过度拟合,从而促进少量样本FS。我们展示了我们方法在说明性示例和几个基准测试方面的功效,在其中我们的方法在选择与竞争方法相比选择信息性特征的准确性更高。此外,我们表明,当应用于测试数据时,我们的FS会导致改进的分类和更好的概括。
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当我们希望将其用作生成模型时,任何显式的功能表示$ f $都会受到两个主要障碍的阻碍:设计$ f $,以便采样快速,并估计$ z = \ int f $ ^{ - 1} f $集成到1。随着$ f $本身变得复杂,这变得越来越复杂。在本文中,我们表明,当通过让网络代表目标密度的累积分布函数并应用积极的基本定理,可以通过神经网络对一维条件密度进行建模时,可以精确地计算出$ z $。 。我们还得出了一种快速算法,用于通过逆变换方法从产生的表示。通过将这些原理扩展到更高的维度,我们介绍了\ textbf {神经逆变换采样器(NITS)},这是一个新颖的深度学习框架,用于建模和从一般,多维,紧凑的概率密度。 NIT是一个高度表达性的密度估计器,具有端到端的可不同性,快速采样以及精确且廉价的可能性评估。我们通过将其应用于现实,高维密度估计任务来证明NIT的适用性:基于CIFAR-10数据集对基于可能性的生成模型,以及基于基准数据集的UCI套件的密度估计,nits可以在其中产生令人信服的结果或超越或超越或超越或超越或超越或超越或超越或超越。艺术状态。
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异常(或异常值)在现实世界的经验观察中普遍存在,并且潜在地掩盖了重要的基础结构。准确识别异常样品对于下游数据分析任务的成功至关重要。为了自动识别异常,我们提出了概率鲁棒性自动编码器(PRAE)。 PRAE的目的是同时删除异常值并确定嵌入式样品的低维表示。我们首先提出了强大的自动编码器(RAE)目标,作为将数据拆分为嵌入式和离群值的最小化问题。我们的目标旨在排除离群值,同时包括可以使用自动编码器(AE)有效重建的样本(Inliers)的子集。 RAE最小化自动编码器的重建误差,同时合并尽可能多的样品。可以通过减去$ \ ell_0 $ norm对重建项中所选样本的数量进行$ \ ell_0 $ norm来制定这一点。不幸的是,这导致了一个棘手的组合问题。因此,我们提出了两种RAE的概率放松,它们是可区分的,可以减轻组合搜索的需求。我们证明,解决PRAE问题的解决方案等效于RAE的解决方案。我们使用合成数据来表明PRAE可以准确地删除广泛污染水平的异常值。最后,我们证明,使用PRAE进行异常检测会导致各种基准数据集中的最新结果。
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通过潜在树形图形模型建模高维数据的分布是多个科学域中的一种普遍存在的方法。常见的任务是推断底层树结构,仅给出其终端节点的观察。树恢复的许多算法是计算密集型的,这将其适用于中等大小的树木。对于大树,一种共同的方法,被称为剥夺和征服,是以两步恢复树结构。首先,将结构分别恢复终端节点的多个可能随机子集。其次,合并生成的子树以形成一棵树。在这里,我们开发频谱自上而下的恢复(STDR),确定性分割和征服方法来推断出大潜在树模型。与以前的方法不同,STDR基于与观察到的节点相关的合适的LAPLACIAN矩阵的FIEDLER向量,以非随机方式分配终端节点。我们证明,在某些条件下,这种分区与树结构一致。反过来,这导致了小远子的显着更简单的合并程序。我们证明了STDR在统计上是一致的,并绑定了以高概率准确恢复树所需的样本数量。使用来自近几种常见树模型的模拟数据在系统发育中,我们证明STDR在运行时具有显着的优势,具有改善或类似的准确性。
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In this paper, we formulate the problem of predicting a geolocation from free text as a sequence-to-sequence problem. Using this formulation, we obtain a geocoding model by training a T5 encoder-decoder transformer model using free text as an input and geolocation as an output. The geocoding model was trained on geo-tagged wikidump data with adaptive cell partitioning for the geolocation representation. All of the code including Rest-based application, dataset and model checkpoints used in this work are publicly available.
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Real-life tools for decision-making in many critical domains are based on ranking results. With the increasing awareness of algorithmic fairness, recent works have presented measures for fairness in ranking. Many of those definitions consider the representation of different ``protected groups'', in the top-$k$ ranked items, for any reasonable $k$. Given the protected groups, confirming algorithmic fairness is a simple task. However, the groups' definitions may be unknown in advance. In this paper, we study the problem of detecting groups with biased representation in the top-$k$ ranked items, eliminating the need to pre-define protected groups. The number of such groups possible can be exponential, making the problem hard. We propose efficient search algorithms for two different fairness measures: global representation bounds, and proportional representation. Then we propose a method to explain the bias in the representations of groups utilizing the notion of Shapley values. We conclude with an experimental study, showing the scalability of our approach and demonstrating the usefulness of the proposed algorithms.
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Neural volumetric representations have become a widely adopted model for radiance fields in 3D scenes. These representations are fully implicit or hybrid function approximators of the instantaneous volumetric radiance in a scene, which are typically learned from multi-view captures of the scene. We investigate the new task of neural volume super-resolution - rendering high-resolution views corresponding to a scene captured at low resolution. To this end, we propose a neural super-resolution network that operates directly on the volumetric representation of the scene. This approach allows us to exploit an advantage of operating in the volumetric domain, namely the ability to guarantee consistent super-resolution across different viewing directions. To realize our method, we devise a novel 3D representation that hinges on multiple 2D feature planes. This allows us to super-resolve the 3D scene representation by applying 2D convolutional networks on the 2D feature planes. We validate the proposed method's capability of super-resolving multi-view consistent views both quantitatively and qualitatively on a diverse set of unseen 3D scenes, demonstrating a significant advantage over existing approaches.
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Out-of-distribution (OOD) detection has attracted a large amount of attention from the machine learning research community in recent years due to its importance in deployed systems. Most of the previous studies focused on the detection of OOD samples in the multi-class classification task. However, OOD detection in the multi-label classification task remains an underexplored domain. In this research, we propose YolOOD - a method that utilizes concepts from the object detection domain to perform OOD detection in the multi-label classification task. Object detection models have an inherent ability to distinguish between objects of interest (in-distribution) and irrelevant objects (e.g., OOD objects) on images that contain multiple objects from different categories. These abilities allow us to convert a regular object detection model into an image classifier with inherent OOD detection capabilities with just minor changes. We compare our approach to state-of-the-art OOD detection methods and demonstrate YolOOD's ability to outperform these methods on a comprehensive suite of in-distribution and OOD benchmark datasets.
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We introduce MuJoCo MPC (MJPC), an open-source, interactive application and software framework for real-time predictive control, based on MuJoCo physics. MJPC allows the user to easily author and solve complex robotics tasks, and currently supports three shooting-based planners: derivative-based iLQG and Gradient Descent, and a simple derivative-free method we call Predictive Sampling. Predictive Sampling was designed as an elementary baseline, mostly for its pedagogical value, but turned out to be surprisingly competitive with the more established algorithms. This work does not present algorithmic advances, and instead, prioritises performant algorithms, simple code, and accessibility of model-based methods via intuitive and interactive software. MJPC is available at: github.com/deepmind/mujoco_mpc, a video summary can be viewed at: dpmd.ai/mjpc.
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In this paper, we present a method for converting a given scene image into a sketch using different types and multiple levels of abstraction. We distinguish between two types of abstraction. The first considers the fidelity of the sketch, varying its representation from a more precise portrayal of the input to a looser depiction. The second is defined by the visual simplicity of the sketch, moving from a detailed depiction to a sparse sketch. Using an explicit disentanglement into two abstraction axes -- and multiple levels for each one -- provides users additional control over selecting the desired sketch based on their personal goals and preferences. To form a sketch at a given level of fidelity and simplification, we train two MLP networks. The first network learns the desired placement of strokes, while the second network learns to gradually remove strokes from the sketch without harming its recognizability and semantics. Our approach is able to generate sketches of complex scenes including those with complex backgrounds (e.g., natural and urban settings) and subjects (e.g., animals and people) while depicting gradual abstractions of the input scene in terms of fidelity and simplicity.
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