基于文本的人检索的核心问题是如何弥合多模式数据之间的异质差距。以前的许多方法,用于学习以\ textbf {交叉模式分布共识预测(CDCP)}方式学习潜在的常见歧管映射范式。当将某个模态分布到公共歧管中的映射特征时,相反模态的特征分布是完全不可见的。也就是说,如何实现跨模式分布共识,以便将多模式特征嵌入和对齐构建的跨模式公共歧管中,这完全取决于模型本身的经验,而不是实际情况。通过这种方法,不可避免的是,多模式数据在共同的歧管中不能很好地对齐,这最终导致了次优的检索性能。为了克服此\ textbf {CDCP困境},我们提出了一种称为lbul的新颖算法,以学习基于文本的人检索的一致的跨模式公共歧管(C $^{3} $ M)。正如中文的谚语所说,我们方法的核心思想是``\ textit {san si er hou xing}',即\ textbf {thee thee thee thee thee you lap leak(lbul)}。 LBUL的常见歧管映射机制包含一个看起来的步骤和跳跃步骤。与基于CDCP的方法相比,LBUL考虑了视觉和文本方式的分布特征,然后将数据从某种模式嵌入到C $^{3} $ M中以获得更固体的交叉模式分布共识,从而获得了优质检索准确性。我们对两个基于文本的人检索数据集Cuhk-Pedes和RSTPREID评估了建议的方法。实验结果表明,所提出的LBUL胜过先前的方法,并实现了最新的性能。
translated by 谷歌翻译
给定自然语言描述,基于文本的人检索旨在从大规模人物图像数据库中识别目标人的图像。现有方法通常面对\ textbf {颜色过度盟军问题},这意味着在匹配跨模式数据时,模型在很大程度上依赖颜色信息。实际上,颜色信息是检索的重要决策,但是对颜色的过度依赖会分散模型从其他关键线索(例如纹理信息,结构信息等)中分散注意力,从而导致了次优的检索表现。为了解决这个问题,在本文中,我们建议\ textbf {c} apture \ textbf {a} ll-round \ textbf {i} nformation \ textbf {b} eyond \ textbf {c} olor(c} olor( )通过用于基于文本的人检索的共同优化的多分支体系结构。 CAIBC包含三个分支,包括RGB分支,灰度(GRS)分支和颜色(CLR)分支。此外,为了以平衡和有效的方式充分使用全方位信息,采用了相互学习机制来启用三个分支,这些分支可以参与信息的各个方面,以相互交流和学习。进行了广泛的实验分析,以评估我们在\ textbf {有监督}和\ textbf {弱监督}基于文本的人检索的\ textbf {pertexbf {pertegbf {pertegbf {cuhk-pedes和rstpreid数据集上的提议的CAIBC方法,这表明CAIBC显着超过现有的方法和现有方法。在这三个任务上实现最先进的性能。
translated by 谷歌翻译
我们建议采用统计回归作为投影操作员,以使数据驱动以数据为基础的Mori-Zwanzig形式主义中的运营商学习。我们提出了一种原则性方法,用于为任何回归模型提取Markov和内存操作员。我们表明,线性回归的选择导致了基于Mori的投影操作员最近提出的数据驱动的学习算法,这是一种高阶近似Koopman学习方法。我们表明,更具表现力的非线性回归模型自然填补了高度理想化和计算有效的MORI投影操作符和最佳迄今为止计算上最佳的Zwanzig投影仪之间的差距。我们进行了数值实验,并提取了一系列基于回归的投影的运算符,包括线性,多项式,样条和基于神经网络的回归,随着回归模型的复杂性的增加而显示出渐进的改进。我们的命题提供了一个通用框架来提取内存依赖性校正,并且可以轻松地应用于文献中固定动力学系统的一系列数据驱动的学习方法。
translated by 谷歌翻译
湍流无处不在,获得有效,准确且可概括的订单模型仍然是一个具有挑战性的问题。该手稿开发了减少拉格朗日模型的湍流模型的层次结构,以研究和比较在拉格朗日框架内实施平滑的粒子流体动力学(SPH)结构与嵌入神经网络(NN)作为通用函数近似器中的效果。 SPH是用于近似流体力学方程的无网格拉格朗日方法。从基于神经网络(NN)的拉格朗日加速运算符的参数化开始,该层次结构逐渐结合了一个弱化和参数化的SPH框架,该框架可以执行物理对称性和保护定律。开发了两个新的参数化平滑核,其中包含在完全参数化的SPH模拟器中,并与立方和四分之一的平滑核进行了比较。对于每个模型,我们使用基于梯度的优化最小化的不同损耗函数,其中使用自动分化(AD)和灵敏度分析(SA)获得了有效的梯度计算。每个模型均经过两个地面真理(GT)数据集训练,该数据集与每周可压缩的均质各向同性湍流(hit),(1)使用弱压缩SPH的验证集,(2)来自直接数值模拟(DNS)的高忠诚度集。数值证据表明:(a)对“合成” SPH数据的方法验证; (b)嵌入在SPH框架中近似状态方程的NN的能力; (b)每个模型都能插入DNS数据; (c)编码更多的SPH结构可提高对不同湍流的马赫数和时间尺度的普遍性; (d)引入两个新型参数化平滑核可提高SPH比标准平滑核的准确性。
translated by 谷歌翻译
Given the increasingly intricate forms of partial differential equations (PDEs) in physics and related fields, computationally solving PDEs without analytic solutions inevitably suffers from the trade-off between accuracy and efficiency. Recent advances in neural operators, a kind of mesh-independent neural-network-based PDE solvers, have suggested the dawn of overcoming this challenge. In this emerging direction, Koopman neural operator (KNO) is a representative demonstration and outperforms other state-of-the-art alternatives in terms of accuracy and efficiency. Here we present KoopmanLab, a self-contained and user-friendly PyTorch module of the Koopman neural operator family for solving partial differential equations. Beyond the original version of KNO, we develop multiple new variants of KNO based on different neural network architectures to improve the general applicability of our module. These variants are validated by mesh-independent and long-term prediction experiments implemented on representative PDEs (e.g., the Navier-Stokes equation and the Bateman-Burgers equation) and ERA5 (i.e., one of the largest high-resolution data sets of global-scale climate fields). These demonstrations suggest the potential of KoopmanLab to be considered in diverse applications of partial differential equations.
translated by 谷歌翻译
Different people speak with diverse personalized speaking styles. Although existing one-shot talking head methods have made significant progress in lip sync, natural facial expressions, and stable head motions, they still cannot generate diverse speaking styles in the final talking head videos. To tackle this problem, we propose a one-shot style-controllable talking face generation framework. In a nutshell, we aim to attain a speaking style from an arbitrary reference speaking video and then drive the one-shot portrait to speak with the reference speaking style and another piece of audio. Specifically, we first develop a style encoder to extract dynamic facial motion patterns of a style reference video and then encode them into a style code. Afterward, we introduce a style-controllable decoder to synthesize stylized facial animations from the speech content and style code. In order to integrate the reference speaking style into generated videos, we design a style-aware adaptive transformer, which enables the encoded style code to adjust the weights of the feed-forward layers accordingly. Thanks to the style-aware adaptation mechanism, the reference speaking style can be better embedded into synthesized videos during decoding. Extensive experiments demonstrate that our method is capable of generating talking head videos with diverse speaking styles from only one portrait image and an audio clip while achieving authentic visual effects. Project Page: https://github.com/FuxiVirtualHuman/styletalk.
translated by 谷歌翻译
Humans have internal models of robots (like their physical capabilities), the world (like what will happen next), and their tasks (like a preferred goal). However, human internal models are not always perfect: for example, it is easy to underestimate a robot's inertia. Nevertheless, these models change and improve over time as humans gather more experience. Interestingly, robot actions influence what this experience is, and therefore influence how people's internal models change. In this work we take a step towards enabling robots to understand the influence they have, leverage it to better assist people, and help human models more quickly align with reality. Our key idea is to model the human's learning as a nonlinear dynamical system which evolves the human's internal model given new observations. We formulate a novel optimization problem to infer the human's learning dynamics from demonstrations that naturally exhibit human learning. We then formalize how robots can influence human learning by embedding the human's learning dynamics model into the robot planning problem. Although our formulations provide concrete problem statements, they are intractable to solve in full generality. We contribute an approximation that sacrifices the complexity of the human internal models we can represent, but enables robots to learn the nonlinear dynamics of these internal models. We evaluate our inference and planning methods in a suite of simulated environments and an in-person user study, where a 7DOF robotic arm teaches participants to be better teleoperators. While influencing human learning remains an open problem, our results demonstrate that this influence is possible and can be helpful in real human-robot interaction.
translated by 谷歌翻译
We introduce a new tool for stochastic convex optimization (SCO): a Reweighted Stochastic Query (ReSQue) estimator for the gradient of a function convolved with a (Gaussian) probability density. Combining ReSQue with recent advances in ball oracle acceleration [CJJJLST20, ACJJS21], we develop algorithms achieving state-of-the-art complexities for SCO in parallel and private settings. For a SCO objective constrained to the unit ball in $\mathbb{R}^d$, we obtain the following results (up to polylogarithmic factors). We give a parallel algorithm obtaining optimization error $\epsilon_{\text{opt}}$ with $d^{1/3}\epsilon_{\text{opt}}^{-2/3}$ gradient oracle query depth and $d^{1/3}\epsilon_{\text{opt}}^{-2/3} + \epsilon_{\text{opt}}^{-2}$ gradient queries in total, assuming access to a bounded-variance stochastic gradient estimator. For $\epsilon_{\text{opt}} \in [d^{-1}, d^{-1/4}]$, our algorithm matches the state-of-the-art oracle depth of [BJLLS19] while maintaining the optimal total work of stochastic gradient descent. We give an $(\epsilon_{\text{dp}}, \delta)$-differentially private algorithm which, given $n$ samples of Lipschitz loss functions, obtains near-optimal optimization error and makes $\min(n, n^2\epsilon_{\text{dp}}^2 d^{-1}) + \min(n^{4/3}\epsilon_{\text{dp}}^{1/3}, (nd)^{2/3}\epsilon_{\text{dp}}^{-1})$ queries to the gradients of these functions. In the regime $d \le n \epsilon_{\text{dp}}^{2}$, where privacy comes at no cost in terms of the optimal loss up to constants, our algorithm uses $n + (nd)^{2/3}\epsilon_{\text{dp}}^{-1}$ queries and improves recent advancements of [KLL21, AFKT21]. In the moderately low-dimensional setting $d \le \sqrt n \epsilon_{\text{dp}}^{3/2}$, our query complexity is near-linear.
translated by 谷歌翻译
Through a study of multi-gas mixture datasets, we show that in multi-component spectral analysis, the number of functional or non-functional principal components required to retain the essential information is the same as the number of independent constituents in the mixture set. Due to the mutual in-dependency among different gas molecules, near one-to-one projection from the principal component to the mixture constituent can be established, leading to a significant simplification of spectral quantification. Further, with the knowledge of the molar extinction coefficients of each constituent, a complete principal component set can be extracted from the coefficients directly, and few to none training samples are required for the learning model. Compared to other approaches, the proposed methods provide fast and accurate spectral quantification solutions with a small memory size needed.
translated by 谷歌翻译
We study the task of learning state representations from potentially high-dimensional observations, with the goal of controlling an unknown partially observable system. We pursue a direct latent model learning approach, where a dynamic model in some latent state space is learned by predicting quantities directly related to planning (e.g., costs) without reconstructing the observations. In particular, we focus on an intuitive cost-driven state representation learning method for solving Linear Quadratic Gaussian (LQG) control, one of the most fundamental partially observable control problems. As our main results, we establish finite-sample guarantees of finding a near-optimal state representation function and a near-optimal controller using the directly learned latent model. To the best of our knowledge, despite various empirical successes, prior to this work it was unclear if such a cost-driven latent model learner enjoys finite-sample guarantees. Our work underscores the value of predicting multi-step costs, an idea that is key to our theory, and notably also an idea that is known to be empirically valuable for learning state representations.
translated by 谷歌翻译