In order to guarantee the correctness of business processes, not only control-flow errors but also data-flow errors should be considered. The control-flow errors mainly focus on deadlock, livelock, soundness, and so o...In order to guarantee the correctness of business processes, not only control-flow errors but also data-flow errors should be considered. The control-flow errors mainly focus on deadlock, livelock, soundness, and so on. However, there are not too many methods for detecting data-flow errors. This paper defines Petri nets with data operations(PN-DO) that can model the operations on data such as read, write and delete. Based on PN-DO, we define some data-flow errors in this paper. We construct a reachability graph with data operations for each PN-DO, and then propose a method to reduce the reachability graph. Based on the reduced reachability graph, data-flow errors can be detected rapidly. A case study is given to illustrate the effectiveness of our methods.展开更多
Existing traffic flow prediction frameworks have already achieved enormous success due to large traffic datasets and capability of deep learning models.However,data privacy and security are always a challenge in every...Existing traffic flow prediction frameworks have already achieved enormous success due to large traffic datasets and capability of deep learning models.However,data privacy and security are always a challenge in every field where data need to be uploaded to the cloud.Federated learning(FL)is an emerging trend for distributed training of data.The primary goal of FL is to train an efficient communication model without compromising data privacy.The traffic data have a robust spatio-temporal correlation,but various approaches proposed earlier have not considered spatial correlation of the traffic data.This paper presents FL-based traffic flow prediction with spatio-temporal correlation.This work uses a differential privacy(DP)scheme for privacy preservation of participant's data.To the best of our knowledge,this is the first time that FL is used for vehicular traffic prediction while considering the spatio-temporal correlation of traffic data with DP preservation.The proposed framework trains the data locally at the client-side with DP.It then uses the model aggregation mechanism federated graph convolutional network(FedGCN)at the server-side to find the average of locally trained models.The results of the proposed work show that the FedGCN model accurately predicts the traffic.DP scheme at client-side helps clients to set a budget for privacy loss.展开更多
为应对电力系统碳排放计算中效率和精度不足的问题,文章提出一种基于时空图神经网络(spatiotemporal graph neural network,ST-GNN)的数据驱动方法,旨在高效计算节点碳排放因子以及支路碳流和碳流损耗。文章首先分析电力系统碳排放流计...为应对电力系统碳排放计算中效率和精度不足的问题,文章提出一种基于时空图神经网络(spatiotemporal graph neural network,ST-GNN)的数据驱动方法,旨在高效计算节点碳排放因子以及支路碳流和碳流损耗。文章首先分析电力系统碳排放流计算的复杂性及传统方法的局限性,进而设计以有功-无功(active and reactive power,PQ)节点、有功-电压(active power and voltage,PV)节点和平衡节点特征为输入的ST-GNN模型,实现碳排放因子及支路碳流的直接计算,并确定支路碳流损耗。其中PQ节点的特征有功功率和无功功率,来源于电力系统运行数据,PV节点的发电功率和电压来自发电机的运行特性,平衡节点的输入包括电压和相位角,确保系统的功率平衡。通过IEEE 9节点、IEEE 57节点和IEEE118节点系统的实验,验证了所提方法的有效性。结果表明,ST-GNN模型在碳排放因子、支路碳流和碳损耗的计算精度上显著优于线性回归、决策树、长短期记忆网络和多层感知机,特别在复杂电力网络中表现突出。该研究为电力系统碳排放监测和优化提供了精准高效的技术支持。展开更多
The utilization of computation resources and reconfiguration time has a large impact on reconfiguration system performance. In order to promote the performance, a dynamical self-reconfigurable mechanism for data-drive...The utilization of computation resources and reconfiguration time has a large impact on reconfiguration system performance. In order to promote the performance, a dynamical self-reconfigurable mechanism for data-driven cell array is proposed. Cells can be fired only when the needed data arrives, and cell array can be worked on two modes: fixed execution and reconfiguration. On reconfiguration mode, cell function and data flow direction are changed automatically at run time according to contexts. Simultaneously using an H-tree interconnection network, through pre-storing multiple application mapping contexts in reconfiguration buffer, multiple applications can execute concurrently and context switching time is the minimal. For verifying system performance, some algorithms are selected for mapping onto the proposed structure, and the amount of configuration contexts and execution time are recorded for statistical analysis. The results show that the proposed self-reconfigurable mechanism can reduce the number of contexts efficiently, and has a low computing time.展开更多
基金supported in part by the National Key R&D Program of China(2017YFB1001804)Shanghai Science and Technology Innovation Action Plan Project(16511100900)
文摘In order to guarantee the correctness of business processes, not only control-flow errors but also data-flow errors should be considered. The control-flow errors mainly focus on deadlock, livelock, soundness, and so on. However, there are not too many methods for detecting data-flow errors. This paper defines Petri nets with data operations(PN-DO) that can model the operations on data such as read, write and delete. Based on PN-DO, we define some data-flow errors in this paper. We construct a reachability graph with data operations for each PN-DO, and then propose a method to reduce the reachability graph. Based on the reduced reachability graph, data-flow errors can be detected rapidly. A case study is given to illustrate the effectiveness of our methods.
文摘Existing traffic flow prediction frameworks have already achieved enormous success due to large traffic datasets and capability of deep learning models.However,data privacy and security are always a challenge in every field where data need to be uploaded to the cloud.Federated learning(FL)is an emerging trend for distributed training of data.The primary goal of FL is to train an efficient communication model without compromising data privacy.The traffic data have a robust spatio-temporal correlation,but various approaches proposed earlier have not considered spatial correlation of the traffic data.This paper presents FL-based traffic flow prediction with spatio-temporal correlation.This work uses a differential privacy(DP)scheme for privacy preservation of participant's data.To the best of our knowledge,this is the first time that FL is used for vehicular traffic prediction while considering the spatio-temporal correlation of traffic data with DP preservation.The proposed framework trains the data locally at the client-side with DP.It then uses the model aggregation mechanism federated graph convolutional network(FedGCN)at the server-side to find the average of locally trained models.The results of the proposed work show that the FedGCN model accurately predicts the traffic.DP scheme at client-side helps clients to set a budget for privacy loss.
文摘为应对电力系统碳排放计算中效率和精度不足的问题,文章提出一种基于时空图神经网络(spatiotemporal graph neural network,ST-GNN)的数据驱动方法,旨在高效计算节点碳排放因子以及支路碳流和碳流损耗。文章首先分析电力系统碳排放流计算的复杂性及传统方法的局限性,进而设计以有功-无功(active and reactive power,PQ)节点、有功-电压(active power and voltage,PV)节点和平衡节点特征为输入的ST-GNN模型,实现碳排放因子及支路碳流的直接计算,并确定支路碳流损耗。其中PQ节点的特征有功功率和无功功率,来源于电力系统运行数据,PV节点的发电功率和电压来自发电机的运行特性,平衡节点的输入包括电压和相位角,确保系统的功率平衡。通过IEEE 9节点、IEEE 57节点和IEEE118节点系统的实验,验证了所提方法的有效性。结果表明,ST-GNN模型在碳排放因子、支路碳流和碳损耗的计算精度上显著优于线性回归、决策树、长短期记忆网络和多层感知机,特别在复杂电力网络中表现突出。该研究为电力系统碳排放监测和优化提供了精准高效的技术支持。
基金the National Natural Science Foundation of China (Nos. 61802304, 61834005, 61772417, 61634004, and 61602377)the Shaanxi Provincial Co-ordination Innovation Project of Science and Technology (No. 2016KTZDGY02-04-02)。
文摘The utilization of computation resources and reconfiguration time has a large impact on reconfiguration system performance. In order to promote the performance, a dynamical self-reconfigurable mechanism for data-driven cell array is proposed. Cells can be fired only when the needed data arrives, and cell array can be worked on two modes: fixed execution and reconfiguration. On reconfiguration mode, cell function and data flow direction are changed automatically at run time according to contexts. Simultaneously using an H-tree interconnection network, through pre-storing multiple application mapping contexts in reconfiguration buffer, multiple applications can execute concurrently and context switching time is the minimal. For verifying system performance, some algorithms are selected for mapping onto the proposed structure, and the amount of configuration contexts and execution time are recorded for statistical analysis. The results show that the proposed self-reconfigurable mechanism can reduce the number of contexts efficiently, and has a low computing time.
