基于异构通信机制的任务映射算法

为提高结合共享存储器和片上网络进行核间通信的多核处理器的通信带宽使用效率,基于异构通信机制,提出一种改进的任务映射算法。使用分支定界算法缩小搜索空间,通过迭代交换任务的位置提高映射质量。实验结果表明,与NMAP算法相比,该算法对于随机任务图的通信代价平均降低18.3%,对于并行排序应用最高降低30.6%。

融合异构图神经网络的时间卷积知识追踪方法

知识追踪任务旨在通过建模学生历史学习序列追踪学生认知水平,进而预测学生未来的答题表现.该文提出一个融合异构图神经网络的时间卷积知识追踪模型(Temporal Convolutional Knowledge Tracing Model with Heterogeneous Graph Neural Network,HG-TCKT),将知识追踪任务重述为基于异构图神经网络的时序边分类问题.具体来说,首先将学习记录构建成包含3种节点类型(学生,习题和技能),2种边类型(学生-习题和习题-技能)的异构图数据,异构图描述了学生交互记录中实体类型之间的丰富关系,使用异构图神经网络缓解交互稀疏的问题,引入异构互注意力机制捕捉不同类型节点间的交互关系,提取不同类型节点的高阶特征.将学生节点和习题节点表征拼接,构造边(学生-习题)的表征.最后,使用时间卷积网络捕捉学生历史交互序列的时序依赖关系从而进行预测.在2个真实教育数据集进行实验证明,HG-TCKT相比当前主流知识追踪方法有更好的预测效果.

一种基于两级K-异步联邦学习的隐私保护入侵检测方案

5G的广泛应用导致物联网的设备和流量激增,降低了物联网入侵检测系统的效率和可靠性。目前的入侵检测系统主要使用同步的分布式深度学习方法,难以应用到现实的分布式异步场景中。另外,在分布式的训练过程中也可能遭遇推断攻击。针对以上问题,提出了一种基于两级K-异步联邦学习的隐私保护入侵检测方案,通过在模型训练的不同阶段使用对应算法,提高异步入侵检测模型训练的收敛性和准确率,并设计了一种梯度屏蔽算法防止系统异步训练过程中的推断攻击。实验结果表明,在强异构场景下,该方案在两个入侵检测数据集上训练的准确率可以分别提高11.8%和9.8%,为提高物联网场景下入侵检测系统的效率、可靠性和安全性提供了一种有效方案。

Ceph分布式存储系统拟态防御设计

针对Ceph分布式存储文件系统相应服务程序,采用拟态防御技术,结合Ceph多副本的存储访问机制,构建了相应服务程序的多个功能等价异构体。设计了相应异构体的分发、执行、判决以及安全威胁的诊断、清洗及恢复拟态防御机制,有效的防御了漏洞、后门和攻击等安全威胁,确保了系统数据的完整性与服务的可靠性。

基于轻量级深度网络的动态人脸跟踪方法

为解决人脸跟踪过程中特征提取速度慢、跟踪实时性不足,尤其在人脸快速大范围移动及多人物视野下极易导致跟丢或错跟的问题,提出基于轻量级深度网络的动态跟踪方法。对人脸图像进行数据增强和人脸区域标注,搭建基于分散注意力机制的异构网络快速提取人脸信息;在此基础上引入观测框动量跟踪算法,有效捕捉包括骤移、骤停、大范围快速移动等在内的人脸信息,结合多元回归函数提升跟踪稳定性。实验结果表明,在跟踪效果上更流畅、高效,实际跟踪速度达52帧每秒,对人脸快速移动、遮挡、复杂场景变换等都有较强的鲁棒性和较高的实时性。

Theil Utility Based Multi-Device Cooperation Mechanism for Service Quality Equilibrium in Ubiquitous Stub Environments

An approach to make heterogeneous devices cooperate with each other to provide ubiquitous service remains a longstanding challenge in ubiquitous environments. In addition, when multi-user request ubiquitous services simultaneously, the arbitrariness in resource allocation process easily leads to non-equilibrium of qualities of multiuser's services. Thus, How to design an effective heterogeneous devices cooperation mechanism that meet the QoS requirements and also equilibrate QoS among multi-user's services becomes a very tough problem. In the paper, Equilibrium Index and Theil Utility function are imported to establish a multidevice equilibrium cooperation model, which is benefit for resource allocation in ubiquitous environments. Then a Theil-Equilibrium based Cooperation Mechanism for multi-service is proposed. Firstly, in order to simplify calculating, a dimensionless processing is introduced. After that, a cooperation approach with Theil-Utility Heuristic algorithm is designed to choose the best solution for the simplified model. At last, the mechanism is simulated in a smart home scenario. The simulation results show that this mechanism outperforms non-equilibrium method by improving almost 40% in internal equilibrium with just reducing 0-2% in the total utility ofall the requested ubiquitous services. These data show that the proposed mechanism performs well in equilibrating qualities of multi-user's ubiquitous services.

Effects of extrusion temperature on microstructure evolution and mechanical properties of heterogeneous Mg−Gd alloy laminates via accumulated extrusion bonding

The influence of extrusion temperature on microstructure and mechanical properties of heterogeneous Mg−1Gd/Mg−13Gd laminate prepared by accumulated extrusion bonding was investigated.The results reveal that the Mg−1Gd/Mg−13Gd laminate forms a significant difference in grain size between the successive layers when extruded at 330℃,and this difference gradually disappears as the extrusion temperature increases from 380 to 430℃.Besides,the growth rate of recrystallized grains in fine-grained layers is faster than that in coarse-grained layers.Moreover,the diffusion ability of Gd element increases with elevating extrusion temperatures,promoting the increase and coarsening of precipitates in fine-grained layers.Tensile tests indicate that the sample extruded at 380℃ has a superior combination of strength and ductility.This is mainly attributed to the synergy of the heterogeneous texture between coarse and fine-grained layers,hetero-deformation induced strengthening and hardening.The fine-grained layers facilitate the activation of prismaticáañslips,while coarse-grained layers make it easier to active basaláañand pyramidalác+añslips,especially for the sample extruded at 380℃.The activation of pyramidalác+añslips contributes to coordinating further plastic deformation.

Atrial fibrosis： an obligatory component of arrhythmia mechanisms in atrial fibrillation？

Advances in clinical and fimdamental research, which have been promoted over last decades have led to a well- established understanding of atrial fibrillation （AF） as an epiphenomenon that despite similar manifestations may have different underlying mechanisms and thus require in- dividualized treatments. With rare exceptions of AF caused by mutations in genes coding ion channels in pa- tients with structurally normal atria, fibrotic replacement of atrial myocardium remains the comer stone of atrial pa- thology in patients with AF.

Real-time Business Network Selection Based on Auction Mechanism

In the framework of heterogeneous wireless networks,it is difficult for every user to obtain QoS-based services anywhere at any time.Due to heterogeneous networks,the dynamic network selection scheme needs to achieve seamless mobility,and also supports the optimization of service quality and load balancing.According to different business characteristics,this paper describes different real-time businesses in utility functions,and solves network selection problems for real-time businesses.Based on auction mechanism,it introduces the upset price in order to maximize online profits.Meanwhile,the network selection scheme is also helpful to control network congestion.The study of real-time business network selection based on auction mechanism can not only meet the demands of service quality of multiple realtime applications,but also achieves load balancing between different networks.

Cooperative wireless networks for better green services

In order to guarantee the overall return on investment (ROI), improve user experience and quality of service (QoS), save energy, reduce electra magnetic interference (EMI) and radiation pollution, and enable the sustainable deployment of new profitable applications and services in heterogeneous wireless networks coexistence reality, this paper proposes a cross-network cooperation mechanism to effectively share network resources and infrastructures, and then adaptively control and match multi-network energy distribution characteristics according to actual user/service requirements in different geographic areas. Some idle or lightly-loaded base stations (BS or BSs) will be temporally turned off for saving energy and reducing EMI. Initial simulation results show that the proposed approach can significantly improve the overall energy efficiency and QoS performance across multiple cooperative wireless networks.

Fraud Detection in Interoperable Information Systems

Interoperability is broad and complex subject being the most critical issue facing businesses that need to access information from multiple systems. The concept of unwanted interoperability can result in fault decision making based on counterfeit data produced by hostile interoperable system. Research in this paper is based on highway toll collection system analysis as representative of hierarchical heterogeneous systems where integration becomes more important than development due to the short time in disposal between the contract signature and implementation. Unwanted interoperability detect mechanism is presented using information collected from different information system levels.