Conventional matrix factorization relies on centralized collection of users' data for recommendation, which might introduce an increased risk of privacy leakage especially when the recommender is untrusted. Existing differentially private matrix factorization methods either assume the recommender is trusted, or can only provide a uniform level of privacy protection for all users and items with untrusted recommender. In this paper, we propose a novel Heterogeneous Differentially Private Matrix Factorization algorithm (denoted as HDPMF) for untrusted recommender. To the best of our knowledge, we are the first to achieve heterogeneous differential privacy for decentralized matrix factorization in untrusted recommender scenario. Specifically, our framework uses modified stretching mechanism with an innovative rescaling scheme to achieve better trade off between privacy and accuracy. Meanwhile, by allocating privacy budget properly, we can capture homogeneous privacy preference within a user/item but heterogeneous privacy preference across different users/items. Theoretical analysis confirms that HDPMF renders rigorous privacy guarantee, and exhaustive experiments demonstrate its superiority especially in strong privacy guarantee, high dimension model and sparse dataset scenario.

小鼠的自动社会行为分析已成为行为神经科学中越来越流行的研究领域。最近，已使用姿势信息（即关键点或骨骼的位置）来解释小鼠的社会行为。然而，很少在现有方法中研究了小鼠关键点基础的社会互动信息的有效编码和解码。特别是，由于高度变形的身体形状和模棱两可的运动模式，建模小鼠之间复杂的社交互动是一项挑战。为了处理交互建模问题，我们在这里提出了一个跨骨骼相互作用图聚合网络（CS-IGANET），以学习自由相互作用的小鼠的丰富动力学，其中使用了跨骨骼节点级交互模块（CS-NLI）建模多级相互作用（即内部，间和跨骨骼相互作用）。此外，我们设计了一种新颖的互动感知变压器（IAT），以动态学习社交行为的图形表示，并更新节点级表示，并在我们提出的互动意识到的自我注意力下的机制的指导下。最后，为了增强我们的模型的表示能力，提出了辅助自我监督的学习任务来衡量跨骨骼节点之间的相似性。标准CRMI13-SKERTON和我们的PDMB-Skeleton数据集的实验结果表明，我们所提出的模型的表现优于其他几种最先进的方法。

基于AI的蛋白质结构预测管道（例如AlphaFold2）已达到了几乎实验的准确性。这些高级管道主要依赖于多个序列比对（MSA）和模板作为输入来从同源序列中学习共进化信息。但是，从蛋白质数据库中搜索MSA和模板很耗时，通常需要数十分钟。因此，我们尝试通过仅使用蛋白质的主要序列来探索快速蛋白质结构预测的极限。提出了Helixfold单一的形式将大规模蛋白质语言模型与AlphaFold2的优质几何学习能力相结合。我们提出的方法，Helixfold单个，首先预先培训是一种大规模蛋白质语言模型（PLM），使用了数以千计的主要序列利用自我监督的学习范式，将用作MSA和模板的替代方法共同进化信息。然后，通过将预训练的PLM和AlphaFold2的必需组件组合在一起，我们获得了一个端到端可区分模型，以仅从主要序列预测原子的3D坐标。 Helixfold-Single在数据集CASP14和Cameo中得到了验证，通过基于MSA的方法，具有大型同源家庭的基于MSA的方法，从而实现了竞争精度。此外，与主流管道进行蛋白质结构预测相比，Helixfold单个的时间比主流管道的时间少得多，这表明其在需要许多预测的任务中的潜力。 HelixFold-Single的守则可在https://github.com/paddlepaddle/paddlehelix/tree/dev/dev/pprotein_folding/helixfold-single上获得，我们还在https://paddlehelix.baidu.com上提供稳定的Web服务。 /app/drug/protein-single/prevast。

最近，在推荐系统领域中，一个关键问题隐约可见 - 没有进行严格评估的有效基准 - 因此，这会导致不可再生的评估和不公平的比较。因此，我们从实践理论和实验的角度进行研究，目的是为严格的评估做出基准建议。关于理论研究，一系列影响整个评估链中建议性能的超级因素通过对2017 - 2020年在八个顶级会议上发表的141篇论文进行的详尽评价进行了系统的总结和分析。然后，我们将它们分类为独立于模型和模型依赖性的超因子，并相应地定义和讨论了不同的严格评估模式。在实验研究中，我们通过将这些超级因子整合以进行严格的评估来发布DaisyREC 2.0文库，从而进行了整体经验研究，以揭示不同超级效应器对建议性能的影响。在理论和实验研究的支持下，我们最终通过提出标准化程序并在六个数据集上的六个评估指标中提供10个最先进的方法来创建严格评估的基准，以作为以后研究的参考。总体而言，我们的工作阐明了建议评估中的问题，为严格的评估提供了潜在的解决方案，并为进一步调查提供了基础。

交通预测在智能交通系统中很重要，有利于交通安全，但由于现实世界交通系统中的复杂和动态的时空依赖性，这是非常具有挑战性的。先前的方法使用预定义或学习的静态图来提取空间相关性。但是，基于静态图形的方法无法挖掘交通网络的演变。研究人员随后为每次切片生成动态图形以反映空间相关性的变化，但它们遵循独立建模的时空依赖性的范例，忽略了串行空间影响。在本文中，我们提出了一种新的基于跨时动态图形的深度学习模型，名为CDGNet，用于交通预测。该模型能够通过利用横行动态图来有效地捕获每个时切片和其历史时片之间的串联空间依赖性。同时，我们设计了稀疏横行动态图的浇注机制，符合现实世界中的稀疏空间相关性。此外，我们提出了一种新颖的编码器解码器架构，用于结合基于交叉时间动态图形的GCN，用于多步行量预测。三个现实世界公共交通数据集的实验结果表明CDGNET优于最先进的基线。我们还提供了一种定性研究来分析我们建筑的有效性。

背景：12个引线ECG是心血管疾病的核心诊断工具。在这里，我们描述并分析了一个集成的深度神经网络架构，从12个引导eCG分类了24个心脏异常。方法：我们提出了挤压和激发reset，以自动学习来自12个引主ECG的深度特征，以识别24个心脏病。在最终完全连接的层中，随着年龄和性别特征增强了深度特征。使用约束网格搜索设置每个类的输出阈值。为了确定为什么该模型的预测不正确，两个专家诊所人员独立地解释了一组关于左轴偏差的一次无序的ECG。结果：采用定制加权精度度量，我们达到了0.684的5倍交叉验证得分，灵敏度和特异性分别为0.758和0.969。我们在完整的测试数据中得分0.520，并在官方挑战排名中排名第21中。在一系列被错误分类的心电图中，两个临床医生和训练标签之间的协议差（临床医生1：Kappa = -0.057，临床医生2：Kappa = -0.159）。相比之下，临床医生之间的协议非常高（Kappa = 0.92）。讨论：与在相同数据上培训的模型相比，所提出的预测模型很好地对验证和隐藏的测试数据进行了良好。我们还发现培训标签的相当不一致，这可能会阻碍更准确的模型的开发。

预训练的模型（PTM）正在革新人工智能（AI）技术。但是，PTM培训的硬件要求非常高，使其成为一小部分人的游戏。因此，我们提出了Patrickstar系统，以降低PTM的硬件要求，并使所有人都可以使用。 Patrickstar使用CPU-GPU异质存储空间来存储模型数据。与现有作品不同，我们在内存块中组织模型数据，并在异质内存中动态分配它们。在热身迭代中收集的运行时内存统计的指导下，块在异质内存中有效地精心策划，并生成较低的CPU-GPU数据传输量和较高的带宽利用率。与零冗余优化器的共生，Patrickstar量表在多个节点上均为多个GPU。 ％使用数据并行性。该系统可以在更大的型号和较大的批次大小上训练任务，这是现有工程无法完成的。实验结果表明，Patrickstar扩展了模型量表2.27和2.5倍，并且始终显示出更高的执行速度。 Patricstar还成功地在32 GPU集群上成功运行了175B GPT3培训任务。我们的代码可在https://github.com/tencent/patrickstar上公开获取。

Benefiting from the intrinsic supervision information exploitation capability, contrastive learning has achieved promising performance in the field of deep graph clustering recently. However, we observe that two drawbacks of the positive and negative sample construction mechanisms limit the performance of existing algorithms from further improvement. 1) The quality of positive samples heavily depends on the carefully designed data augmentations, while inappropriate data augmentations would easily lead to the semantic drift and indiscriminative positive samples. 2) The constructed negative samples are not reliable for ignoring important clustering information. To solve these problems, we propose a Cluster-guided Contrastive deep Graph Clustering network (CCGC) by mining the intrinsic supervision information in the high-confidence clustering results. Specifically, instead of conducting complex node or edge perturbation, we construct two views of the graph by designing special Siamese encoders whose weights are not shared between the sibling sub-networks. Then, guided by the high-confidence clustering information, we carefully select and construct the positive samples from the same high-confidence cluster in two views. Moreover, to construct semantic meaningful negative sample pairs, we regard the centers of different high-confidence clusters as negative samples, thus improving the discriminative capability and reliability of the constructed sample pairs. Lastly, we design an objective function to pull close the samples from the same cluster while pushing away those from other clusters by maximizing and minimizing the cross-view cosine similarity between positive and negative samples. Extensive experimental results on six datasets demonstrate the effectiveness of CCGC compared with the existing state-of-the-art algorithms.

As one of the prevalent methods to achieve automation systems, Imitation Learning (IL) presents a promising performance in a wide range of domains. However, despite the considerable improvement in policy performance, the corresponding research on the explainability of IL models is still limited. Inspired by the recent approaches in explainable artificial intelligence methods, we proposed a model-agnostic explaining framework for IL models called R2RISE. R2RISE aims to explain the overall policy performance with respect to the frames in demonstrations. It iteratively retrains the black-box IL model from the randomized masked demonstrations and uses the conventional evaluation outcome environment returns as the coefficient to build an importance map. We also conducted experiments to investigate three major questions concerning frames' importance equality, the effectiveness of the importance map, and connections between importance maps from different IL models. The result shows that R2RISE successfully distinguishes important frames from the demonstrations.

In this paper we explore the task of modeling (semi) structured object sequences; in particular we focus our attention on the problem of developing a structure-aware input representation for such sequences. In such sequences, we assume that each structured object is represented by a set of key-value pairs which encode the attributes of the structured object. Given a universe of keys, a sequence of structured objects can then be viewed as an evolution of the values for each key, over time. We encode and construct a sequential representation using the values for a particular key (Temporal Value Modeling - TVM) and then self-attend over the set of key-conditioned value sequences to a create a representation of the structured object sequence (Key Aggregation - KA). We pre-train and fine-tune the two components independently and present an innovative training schedule that interleaves the training of both modules with shared attention heads. We find that this iterative two part-training results in better performance than a unified network with hierarchical encoding as well as over, other methods that use a {\em record-view} representation of the sequence \cite{de2021transformers4rec} or a simple {\em flattened} representation of the sequence. We conduct experiments using real-world data to demonstrate the advantage of interleaving TVM-KA on multiple tasks and detailed ablation studies motivating our modeling choices. We find that our approach performs better than flattening sequence objects and also allows us to operate on significantly larger sequences than existing methods.