A step-search sequential quadratic programming method is proposed for solving nonlinear equality constrained stochastic optimization problems. It is assumed that constraint function values and derivatives are available, but only stochastic approximations of the objective function and its associated derivatives can be computed via inexact probabilistic zeroth- and first-order oracles. Under reasonable assumptions, a high-probability bound on the iteration complexity of the algorithm to approximate first-order stationarity is derived. Numerical results on standard nonlinear optimization test problems illustrate the advantages and limitations of our proposed method.

经典的Adagrad方法通过除以平方梯度总和的平方根来适应学习率。由于分母上的此总和正在增加，因此该方法只能随着时间的流逝而降低步进大小，并且需要仔细调整学习率的超级参数。为了克服这一限制，我们介绍了Gradagrad，这是同一家庭中一种自然增长或缩小基于分母中不同积累率的学习率的方法，该方法既可以增加又可以减少。我们表明，它遵守与Adagrad相似的收敛速率，并通过实验证明了其非符号酮适应能力。

时间序列数据出现在各种应用程序中，例如智能运输和环境监测。时间序列分析的基本问题之一是时间序列预测。尽管最近的深度时间序列预测方法取得了成功，但它们仍需要足够的历史价值观察才能进行准确的预测。换句话说，输出长度（或预测范围）与输入和输出长度之和的比率应足够低（例如，0.3）。随着比率的增加（例如，到0.8），预测准确性的不确定性显着增加。在本文中，我们从理论和经验上都表明，通过将相关时间序列检索作为参考文献可以有效地降低不确定性。在理论分析中，我们首先量化不确定性，并显示其与平方误差（MSE）的连接。然后，我们证明，带有参考的模型比没有参考的模型更容易学习，因为检索到的参考可能会降低不确定性。为了凭经验证明基于检索的时间序列预测模型的有效性，我们引入了一种简单而有效的两阶段方法，称为“保留”，该方法由关系检索和内容合成组成。我们还表明，可以轻松地适应时空时间序列和时间序列插补设置。最后，我们评估了现实世界数据集上的延迟，以证明其有效性。

对比度学习是图表学习中的有效无监督方法，对比度学习的关键组成部分在于构建正和负样本。以前的方法通常利用图中节点的接近度作为原理。最近，基于数据增强的对比度学习方法已进步以显示视觉域中的强大力量，一些作品将此方法从图像扩展到图形。但是，与图像上的数据扩展不同，图上的数据扩展远不那么直观，而且很难提供高质量的对比样品，这为改进留出了很大的空间。在这项工作中，通过引入一个对抗性图视图以进行数据增强，我们提出了一种简单但有效的方法，对抗图对比度学习（ARIEL），以在合理的约束中提取信息性的对比样本。我们开发了一种称为稳定训练的信息正则化的新技术，并使用子图抽样以进行可伸缩。我们通过将每个图形实例视为超级节点，从节点级对比度学习到图级。 Ariel始终优于在现实世界数据集上的节点级别和图形级分类任务的当前图对比度学习方法。我们进一步证明，面对对抗性攻击，Ariel更加强大。

对比度学习是图表学习中有效的无监督方法。最近，基于数据增强的对比度学习方法已从图像扩展到图形。但是，大多数先前的作品都直接根据为图像设计的模型进行了调整。与图像上的数据增强不同，图表上的数据扩展远不那么直观，而且很难提供高质量的对比样本，这是对比度学习模型的性能的关键。这为改进现有图形对比学习框架留出了很多空间。在这项工作中，通过引入对抗图视图和信息正常化程序，我们提出了一种简单但有效的方法，即对逆向对比度学习（ARIEL），以在合理的约束中提取信息性的对比样本。它始终优于各种现实世界数据集的节点分类任务中当前的图形对比度学习方法，并进一步提高了图对比度学习的鲁棒性。

图是对物体之间关系的强大表示，吸引了很多关注。图形学习的一个基本挑战是如何在没有标签的情况下训练有效的图形神经网络（GNN）编码器，这些标签既昂贵又耗时。对比学习（CL）是应对这一挑战的最受欢迎的范式之一，该挑战通过区分正和负节点对来训练GNN。尽管最近的CL方法取得了成功，但仍然存在两个爆炸案。首先，如何减少基于随机拓扑的数据增强引入的语义错误。传统CL通过节点级拓扑接近定义正和负节点对，该节点拓扑接近度仅基于图形拓扑，而不论节点属性的语义信息如何，因此某些语义上相似的节点可能被错误地视为负对。其次，如何有效地对现实图形的多重性进行建模，其中节点通过各种关系连接，并且每个关系都可以形成均匀的图层。为了解决这些问题，我们提出了一种新型的多重异质图原型对比度倾斜（X-GAL）框架来提取节点嵌入。 X-GOAL由两个组成部分组成：目标框架，该目标框架学习每个均匀图层的节点嵌入，以及一个对齐正则化，通过对齐层特定的节点嵌入来共同对不同的层进行模拟不同的层。具体而言，目标框架通过简洁的图形转换技术捕获节点级信息，并通过将节点拉到嵌入空间中的同一语义簇中，从而捕获群集级信息。对齐正则化在节点和群集级别的层上对齐嵌入。我们在各种现实世界数据集和下游任务上评估X-GAL，以证明其有效性。

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.

Text clustering and topic extraction are two important tasks in text mining. Usually, these two tasks are performed separately. For topic extraction to facilitate clustering, we can first project texts into a topic space and then perform a clustering algorithm to obtain clusters. To promote topic extraction by clustering, we can first obtain clusters with a clustering algorithm and then extract cluster-specific topics. However, this naive strategy ignores the fact that text clustering and topic extraction are strongly correlated and follow a chicken-and-egg relationship. Performing them separately fails to make them mutually benefit each other to achieve the best overall performance. In this paper, we propose an unsupervised text clustering and topic extraction framework (ClusTop) which integrates text clustering and topic extraction into a unified framework and can achieve high-quality clustering result and extract topics from each cluster simultaneously. Our framework includes four components: enhanced language model training, dimensionality reduction, clustering and topic extraction, where the enhanced language model can be viewed as a bridge between clustering and topic extraction. On one hand, it provides text embeddings with a strong cluster structure which facilitates effective text clustering; on the other hand, it pays high attention on the topic related words for topic extraction because of its self-attention architecture. Moreover, the training of enhanced language model is unsupervised. Experiments on two datasets demonstrate the effectiveness of our framework and provide benchmarks for different model combinations in this framework.

An increasing number of public datasets have shown a marked clinical impact on assessing anatomical structures. However, each of the datasets is small, partially labeled, and rarely investigates severe tumor subjects. Moreover, current models are limited to segmenting specific organs/tumors, which can not be extended to novel domains and classes. To tackle these limitations, we introduce embedding learned from Contrastive Language-Image Pre-training (CLIP) to segmentation models, dubbed the CLIP-Driven Universal Model. The Universal Model can better segment 25 organs and 6 types of tumors by exploiting the semantic relationship between abdominal structures. The model is developed from an assembly of 14 datasets with 3,410 CT scans and evaluated on 6,162 external CT scans from 3 datasets. We rank first on the public leaderboard of the Medical Segmentation Decathlon (MSD) and achieve the state-of-the-art results on Beyond The Cranial Vault (BTCV). Compared with dataset-specific models, the Universal Model is computationally more efficient (6x faster), generalizes better to CT scans from varying sites, and shows stronger transfer learning performance on novel tasks. The design of CLIP embedding enables the Universal Model to be easily extended to new classes without catastrophically forgetting the previously learned classes.