The scalability problem has been one of the most significant barriers limiting the adoption of blockchains. Blockchain sharding is a promising approach to this problem. However, the sharding mechanism introduces a significant number of cross-shard transactions, which are expensive to process. This paper focuses on the transaction allocation problem to reduce the number of cross-shard transactions for better scalability. In particular, we systematically formulate the transaction allocation problem and convert it to the community detection problem on a graph. A deterministic and fast allocation scheme TxAllo is proposed to dynamically infer the allocation of accounts and their associated transactions. It directly optimizes the system throughput, considering both the number of cross-shard transactions and the workload balance among shards. We evaluate the performance of TxAllo on an Ethereum dataset containing over 91 million transactions. Our evaluation results show that for a blockchain with 60 shards, TxAllo reduces the cross-shard transaction ratio from 98% (by using traditional hash-based allocation) to about 12%. In the meantime, the workload balance is well maintained. Compared with other methods, the execution time of TxAllo is almost negligible. For example, when updating the allocation every hour, the execution of TxAllo only takes 0.5 seconds on average, whereas other concurrent works, such as BrokerChain (INFOCOM'22) leveraging the classic METIS method, require 422 seconds.

联邦机器学习是一种多功能和灵活的工具，可以利用来自不同来源的分布式数据，特别是当通信技术快速发展并且现在可以在移动设备上收集前所未有的数据。联邦学习方法不仅利用数据而且挖掘了网络中所有设备的计算能力，以实现更有效的模型培训。尽管如此，虽然大多数传统的联邦学习方法适用于同类数据和任务，但将方法适应不同的异构数据和任务分配是具有挑战性的。这种限制限制了联合学习在现实世界环境中的应用，特别是在医疗保健环境中。灵感来自Meta-Learning的基本思想，在这项研究中，我们提出了一种新的算法，这是联邦学习和荟萃学习的一体化，解决这个问题。此外，由于转移学习的模型泛化的优点，我们通过引入部分参数共享进一步提高了我们的算法。我们命名该方法部分Meta联合学习（PMFL）。最后，我们将算法应用于两个医疗数据集。我们表明我们的算法可以获得最快的训练速度，并在处理异构医疗数据集时实现最佳性能。

近年来，可微弱的建筑搜索（飞镖）已经受到了大量的关注，主要是因为它通过重量分享和连续放松来显着降低计算成本。然而，更近期的作品发现现有的可分辨率NAS技术难以俯视幼稚基线，产生劣化架构作为搜索所需。本文通过将体系结构权重放入高斯分布，而不是直接优化架构参数，而不是直接优化架构参数，而是作为分布学习问题。通过利用自然梯度变分推理（NGVI），可以基于现有的码票来容易地优化架构分布而不会产生更多内存和计算消耗。我们展示了贝叶斯原则的可分解NAS如何益处，提高勘探和提高稳定性。 NAS-BENCH-201和NAS-BENCH-1SHOT1基准数据集的实验结果证实了所提出的框架可以制造的重要改进。此外，我们还在学习参数上只需简单地应用argmax，我们进一步利用了NAS中最近提出的无培训代理，从优化分布中汲取的组架构中选择最佳架构，从而实现最终的架构-ART在NAS-BENCH-201和NAS-BENCH-1SHOT1基准上的结果。我们在飞镖搜索空间中的最佳架构也会分别获得2.37 \％，15.72 \％和24.2 \％的竞争性测试错误，分别在Cifar-10，CiFar-100和Imagenet数据集上。

图形卷积网络对于从图形结构数据进行深入学习而变得必不可少。大多数现有的图形卷积网络都有两个大缺点。首先，它们本质上是低通滤波器，因此忽略了图形信号的潜在有用的中和高频带。其次，固定了现有图卷积过滤器的带宽。图形卷积过滤器的参数仅转换图输入而不更改图形卷积滤波器函数的曲率。实际上，除非我们有专家领域知识，否则我们不确定是否应该在某个点保留或切断频率。在本文中，我们建议自动图形卷积网络（AUTOGCN）捕获图形信号的完整范围，并自动更新图形卷积过滤器的带宽。虽然它基于图谱理论，但我们的自动环境也位于空间中，并具有空间形式。实验结果表明，AutoGCN比仅充当低通滤波器的基线方法实现了显着改善。

虽然可分辨率的架构搜索（飞镖）已成为神经结构中的主流范例（NAS），因为其简单和效率，最近的作品发现，搜索架构的性能几乎可以随着飞镖的优化程序而增加，以及最终的大小由飞镖获得几乎无法表明运营的重要性。上述观察表明，飞镖中的监督信号可能是架构搜索的穷人或不可靠的指标，鼓励有趣和有趣的方向：我们可以衡量不可分辨率范式下的任何培训的运作重要性吗？我们通过在初始化问题的网络修剪中定制NAS提供肯定的答案。随着最近建议的突触突触效力标准在初始化的网络修剪中，我们寻求在没有任何培训的情况下将候选人行动中的候选人行动的重要性进行评分，并提出了一种名为“免费可分辨的架构搜索}（Freedarts）的小说框架” 。我们表明，没有任何培训，具有不同代理度量的自由路由器可以在不同的搜索空间中优于大多数NAS基线。更重要的是，Freedarts是非常内存的高效和计算效率，因为它放弃了架构搜索阶段的培训，使得能够在更灵活的空间上执行架构搜索并消除架构搜索和评估之间的深度间隙。我们希望我们的工作激励从初始化修剪的角度来激发解决NAS的尝试。

Modeling multivariate time series has long been a subject that has attracted researchers from a diverse range of fields including economics, finance, and traffic. A basic assumption behind multivariate time series forecasting is that its variables depend on one another but, upon looking closely, it's fair to say that existing methods fail to fully exploit latent spatial dependencies between pairs of variables. In recent years, meanwhile, graph neural networks (GNNs) have shown high capability in handling relational dependencies. GNNs require well-defined graph structures for information propagation which means they cannot be applied directly for multivariate time series where the dependencies are not known in advance. In this paper, we propose a general graph neural network framework designed specifically for multivariate time series data. Our approach automatically extracts the uni-directed relations among variables through a graph learning module, into which external knowledge like variable attributes can be easily integrated. A novel mix-hop propagation layer and a dilated inception layer are further proposed to capture the spatial and temporal dependencies within the time series. The graph learning, graph convolution, and temporal convolution modules are jointly learned in an end-to-end framework. Experimental results show that our proposed model outperforms the state-of-the-art baseline methods on 3 of 4 benchmark datasets and achieves on-par performance with other approaches on two traffic datasets which provide extra structural information. CCS CONCEPTS• Computing methodologies → Neural networks; Artificial intelligence.

Spatial-temporal graph modeling is an important task to analyze the spatial relations and temporal trends of components in a system. Existing approaches mostly capture the spatial dependency on a fixed graph structure, assuming that the underlying relation between entities is pre-determined. However, the explicit graph structure (relation) does not necessarily reflect the true dependency and genuine relation may be missing due to the incomplete connections in the data. Furthermore, existing methods are ineffective to capture the temporal trends as the RNNs or CNNs employed in these methods cannot capture long-range temporal sequences. To overcome these limitations, we propose in this paper a novel graph neural network architecture, Graph WaveNet, for spatial-temporal graph modeling. By developing a novel adaptive dependency matrix and learn it through node embedding, our model can precisely capture the hidden spatial dependency in the data. With a stacked dilated 1D convolution component whose receptive field grows exponentially as the number of layers increases, Graph WaveNet is able to handle very long sequences. These two components are integrated seamlessly in a unified framework and the whole framework is learned in an end-to-end manner. Experimental results on two public traffic network datasets, METR-LA and PEMS-BAY, demonstrate the superior performance of our algorithm.

Deep learning has revolutionized many machine learning tasks in recent years, ranging from image classification and video processing to speech recognition and natural language understanding. The data in these tasks are typically represented in the Euclidean space. However, there is an increasing number of applications where data are generated from non-Euclidean domains and are represented as graphs with complex relationships and interdependency between objects. The complexity of graph data has imposed significant challenges on existing machine learning algorithms. Recently, many studies on extending deep learning approaches for graph data have emerged. In this survey, we provide a comprehensive overview of graph neural networks (GNNs) in data mining and machine learning fields. We propose a new taxonomy to divide the state-of-the-art graph neural networks into four categories, namely recurrent graph neural networks, convolutional graph neural networks, graph autoencoders, and spatial-temporal graph neural networks. We further discuss the applications of graph neural networks across various domains and summarize the open source codes, benchmark data sets, and model evaluation of graph neural networks. Finally, we propose potential research directions in this rapidly growing field.

Graph neural networks (GNNs) have been demonstrated to be a powerful algorithmic model in broad application fields for their effectiveness in learning over graphs. To scale GNN training up for large-scale and ever-growing graphs, the most promising solution is distributed training which distributes the workload of training across multiple computing nodes. However, the workflows, computational patterns, communication patterns, and optimization techniques of distributed GNN training remain preliminarily understood. In this paper, we provide a comprehensive survey of distributed GNN training by investigating various optimization techniques used in distributed GNN training. First, distributed GNN training is classified into several categories according to their workflows. In addition, their computational patterns and communication patterns, as well as the optimization techniques proposed by recent work are introduced. Second, the software frameworks and hardware platforms of distributed GNN training are also introduced for a deeper understanding. Third, distributed GNN training is compared with distributed training of deep neural networks, emphasizing the uniqueness of distributed GNN training. Finally, interesting issues and opportunities in this field are discussed.

Time series anomaly detection has applications in a wide range of research fields and applications, including manufacturing and healthcare. The presence of anomalies can indicate novel or unexpected events, such as production faults, system defects, or heart fluttering, and is therefore of particular interest. The large size and complex patterns of time series have led researchers to develop specialised deep learning models for detecting anomalous patterns. This survey focuses on providing structured and comprehensive state-of-the-art time series anomaly detection models through the use of deep learning. It providing a taxonomy based on the factors that divide anomaly detection models into different categories. Aside from describing the basic anomaly detection technique for each category, the advantages and limitations are also discussed. Furthermore, this study includes examples of deep anomaly detection in time series across various application domains in recent years. It finally summarises open issues in research and challenges faced while adopting deep anomaly detection models.