多年来，3D形状抽象引起了极大的兴趣。除了诸如网格和体素之类的低级表示外，研究人员还试图用基本的几何原始素来抽象的语义上抽象的复杂对象。最近的深度学习方法在很大程度上依赖于数据集，而一般性的一般性有限。此外，准确地将对象抽象为少数原始物仍然是一个挑战。在本文中，我们提出了一种新型的非参数贝叶斯统计方法来推断从点云中推断出由未知数的几何原始物组成的抽象。我们将点的生成模拟为从高斯超质锥模型（GSTM）的无限混合物采样的观测值。我们的方法将抽象作为聚类问题提出，其中：1）通过中国餐厅过程（CRP）将每个点分配给集群； 2）针对每个集群优化了原始表示形式，3）合并后制品合并以提供简洁的表示。我们在两个数据集上进行了广泛的实验。结果表明，我们的方法在准确性方面优于最先进的方法，并且可以推广到各种类型的对象。

在计算机愿景中已经研究了具有基本几何基元的对象。在几何原语中，超级助理性是众所周知的，其简单的隐式表达式和能力表示具有少数参数的各种形状。然而，作为第一个和最重要的步骤，从3D数据准确且强大地恢复超级助理仍然仍然具有挑战性。现有方法受到本地最佳的影响，并且对现实世界方案中的噪声和异常值敏感，导致捕获几何形状频繁失败。在本文中，我们提出了从点云中恢复超级化的第一种概率方法。我们的方法在超级式的参数表面上构建了高斯均匀的混合物模型（GUM），其明确地模拟了异常值和噪声的产生。超级恢复被制定为最大似然估计（MLE）问题。我们提出了一种算法，期望，最大化和切换（EMS）来解决这个问题，其中：（1）从后视角预测异常值; （2）SuperQuadric参数由信任区域反射算法进行优化; （3）通过在编码类似SuperQuadrics的参数之间进行全局搜索和切换，避免了本地Optima。我们表明我们的方法可以扩展到复杂对象的多叠加恢复。所提出的方法在合成和现实世界数据集的准确性，效率和鲁棒性方面优于最先进的。代码将被释放。

长期以来，PATH规划一直是机器人技术的主要研究领域之一，PRM和RRT是最有效的计划者之一。尽管通常非常有效，但这些基于抽样的计划者在“狭窄通道”的重要情况下可能会变得昂贵。本文开发了专门为狭窄通道问题制定的路径规划范例。核心是基于计划由椭圆形工会封装的刚体机器人的计划。每个环境特征都使用具有$ \ Mathcal {C}^1 $边界的严格凸面来表示几何（例如，超级方面）。这样做的主要好处是，配置空间障碍物可以以封闭形式明确地进行参数化，从而可以使用先验知识来避免采样不可行的配置。然后，通过表征针对多个椭圆形的紧密体积，可以保证涉及旋转的机器人过渡无碰撞，而无需执行传统的碰撞检测。此外，通过与随机抽样策略结合使用，可以将提出的计划框架扩展到解决较高的维度问题，在该问题中，机器人具有移动的基础和铰接的附属物。基准结果表明，所提出的框架通常优于基于采样的计划者的计算时间和成功率，在找到单身机器人和具有较高维度配置空间的狭窄走廊的路径方面。使用建议的框架进行了物理实验，在人形机器人中进一步证明，该机器人在几个混乱的环境中行走，通道狭窄。

We propose a distributionally robust return-risk model for Markov decision processes (MDPs) under risk and reward ambiguity. The proposed model optimizes the weighted average of mean and percentile performances, and it covers the distributionally robust MDPs and the distributionally robust chance-constrained MDPs (both under reward ambiguity) as special cases. By considering that the unknown reward distribution lies in a Wasserstein ambiguity set, we derive the tractable reformulation for our model. In particular, we show that that the return-risk model can also account for risk from uncertain transition kernel when one only seeks deterministic policies, and that a distributionally robust MDP under the percentile criterion can be reformulated as its nominal counterpart at an adjusted risk level. A scalable first-order algorithm is designed to solve large-scale problems, and we demonstrate the advantages of our proposed model and algorithm through numerical experiments.

Cooperative multi-agent reinforcement learning (c-MARL) is widely applied in safety-critical scenarios, thus the analysis of robustness for c-MARL models is profoundly important. However, robustness certification for c-MARLs has not yet been explored in the community. In this paper, we propose a novel certification method, which is the first work to leverage a scalable approach for c-MARLs to determine actions with guaranteed certified bounds. c-MARL certification poses two key challenges compared with single-agent systems: (i) the accumulated uncertainty as the number of agents increases; (ii) the potential lack of impact when changing the action of a single agent into a global team reward. These challenges prevent us from directly using existing algorithms. Hence, we employ the false discovery rate (FDR) controlling procedure considering the importance of each agent to certify per-state robustness and propose a tree-search-based algorithm to find a lower bound of the global reward under the minimal certified perturbation. As our method is general, it can also be applied in single-agent environments. We empirically show that our certification bounds are much tighter than state-of-the-art RL certification solutions. We also run experiments on two popular c-MARL algorithms: QMIX and VDN, in two different environments, with two and four agents. The experimental results show that our method produces meaningful guaranteed robustness for all models and environments. Our tool CertifyCMARL is available at https://github.com/TrustAI/CertifyCMA

Real-time individual endpoint prediction has always been a challenging task but of great clinic utility for both patients and healthcare providers. With 6,879 chronic kidney disease stage 4 (CKD4) patients as a use case, we explored the feasibility and performance of gated recurrent units with decay that models Weibull probability density function (GRU-D-Weibull) as a semi-parametric longitudinal model for real-time individual endpoint prediction. GRU-D-Weibull has a maximum C-index of 0.77 at 4.3 years of follow-up, compared to 0.68 achieved by competing models. The L1-loss of GRU-D-Weibull is ~66% of XGB(AFT), ~60% of MTLR, and ~30% of AFT model at CKD4 index date. The average absolute L1-loss of GRU-D-Weibull is around one year, with a minimum of 40% Parkes serious error after index date. GRU-D-Weibull is not calibrated and significantly underestimates true survival probability. Feature importance tests indicate blood pressure becomes increasingly important during follow-up, while eGFR and blood albumin are less important. Most continuous features have non-linear/parabola impact on predicted survival time, and the results are generally consistent with existing knowledge. GRU-D-Weibull as a semi-parametric temporal model shows advantages in built-in parameterization of missing, native support for asynchronously arrived measurement, capability of output both probability and point estimates at arbitrary time point for arbitrary prediction horizon, improved discrimination and point estimate accuracy after incorporating newly arrived data. Further research on its performance with more comprehensive input features, in-process or post-process calibration are warranted to benefit CKD4 or alike terminally-ill patients.

We propose the first joint audio-video generation framework that brings engaging watching and listening experiences simultaneously, towards high-quality realistic videos. To generate joint audio-video pairs, we propose a novel Multi-Modal Diffusion model (i.e., MM-Diffusion), with two-coupled denoising autoencoders. In contrast to existing single-modal diffusion models, MM-Diffusion consists of a sequential multi-modal U-Net for a joint denoising process by design. Two subnets for audio and video learn to gradually generate aligned audio-video pairs from Gaussian noises. To ensure semantic consistency across modalities, we propose a novel random-shift based attention block bridging over the two subnets, which enables efficient cross-modal alignment, and thus reinforces the audio-video fidelity for each other. Extensive experiments show superior results in unconditional audio-video generation, and zero-shot conditional tasks (e.g., video-to-audio). In particular, we achieve the best FVD and FAD on Landscape and AIST++ dancing datasets. Turing tests of 10k votes further demonstrate dominant preferences for our model. The code and pre-trained models can be downloaded at https://github.com/researchmm/MM-Diffusion.

Variational autoencoders (VAEs) are powerful tools for learning latent representations of data used in a wide range of applications. In practice, VAEs usually require multiple training rounds to choose the amount of information the latent variable should retain. This trade-off between the reconstruction error (distortion) and the KL divergence (rate) is typically parameterized by a hyperparameter $\beta$. In this paper, we introduce Multi-Rate VAE (MR-VAE), a computationally efficient framework for learning optimal parameters corresponding to various $\beta$ in a single training run. The key idea is to explicitly formulate a response function that maps $\beta$ to the optimal parameters using hypernetworks. MR-VAEs construct a compact response hypernetwork where the pre-activations are conditionally gated based on $\beta$. We justify the proposed architecture by analyzing linear VAEs and showing that it can represent response functions exactly for linear VAEs. With the learned hypernetwork, MR-VAEs can construct the rate-distortion curve without additional training and can be deployed with significantly less hyperparameter tuning. Empirically, our approach is competitive and often exceeds the performance of multiple $\beta$-VAEs training with minimal computation and memory overheads.

Approximating Martingale Process (AMP) is proven to be effective for variance reduction in reinforcement learning (RL) in specific cases such as Multiclass Queueing Networks. However, in the already proven cases, the state space is relatively small and all possible state transitions can be iterated through. In this paper, we consider systems in which state space is large and have uncertainties when considering state transitions, thus making AMP a generalized variance-reduction method in RL. Specifically, we will investigate the application of AMP in ride-hailing systems like Uber, where Proximal Policy Optimization (PPO) is incorporated to optimize the policy of matching drivers and customers.

Conventional fine-tuning encounters increasing difficulties given the size of current Pre-trained Language Models, which makes parameter-efficient tuning become the focal point of frontier research. Previous methods in this field add tunable adapters into MHA or/and FFN of Transformer blocks to enable PLMs achieve transferability. However, as an important part of Transformer architecture, the power of layer normalization for parameter-efficent tuning is ignored. In this paper, we first propose LN-tuning, by tuning the gain and bias term of Layer Normalization module with only 0.03\% parameters, which is of high time-efficency and significantly superior to baselines which are less than 0.1\% tunable parameters. Further, we study the unified framework of combining LN-tuning with previous ones and we find that: (1) the unified framework of combining prefix-tuning, the adapter-based method working on MHA, and LN-tuning achieves SOTA performance. (2) unified framework which tunes MHA and LayerNorm simultaneously can get performance improvement but those which tune FFN and LayerNorm simultaneous will cause performance decrease. Ablation study validates LN-tuning is of no abundant parameters and gives a further understanding of it.