The virtual network embedding/mapping problem is an important issue in network virtualization in Software-Defined Networking(SDN).It is mainly concerned with mapping virtual network requests,which could be a set of SD...The virtual network embedding/mapping problem is an important issue in network virtualization in Software-Defined Networking(SDN).It is mainly concerned with mapping virtual network requests,which could be a set of SDN flows,onto a shared substrate network automatically and efficiently.Previous researches mainly focus on developing heuristic algorithms for general topology virtual network.In practice however,the virtual network is usually generated with specific topology for specific purpose.Thus,it is a challenge to optimize the heuristic algorithms with these topology information.In order to deal with this problem,we propose a topology-cognitive algorithm framework,which is composed of a guiding principle for topology algorithm developing and a compound algorithm.The compound algorithm is composed of several subalgorithms,which are optimized for specific topologies.We develop star,tree,and ring topology algorithms as examples,other subalgorithms can be easily achieved following the same framework.The simulation results show that the topology-cognitive algorithm framework is effective in developing new topology algorithms,and the developed compound algorithm greatly enhances the performance of the Revenue/Cost(R/C) ratio and the Runtime than traditional heuristic algorithms for multi-topology virtual network embedding problem.展开更多
In this paper, a fast half-pixel motion estimation algorithm and its corresponding hardware architecture is presented. Unlike three steps are needed in typical half-pixel motion estimation algorithm, the presented alg...In this paper, a fast half-pixel motion estimation algorithm and its corresponding hardware architecture is presented. Unlike three steps are needed in typical half-pixel motion estimation algorithm, the presented algorithm needs only two steps to obtain all the interpolated pixels of an entire 8x8 block. The proposed architecture works in a parallel way and is simulated by Modelsirn 6.5 SE, synthesized to the Xilinx Virtex4 XC4VLX15 FPGA device. The implementation results show that this architecture can achieve 190 MHz and 10 clock cycles are reduced to complete the entire interpolation process when compared with typical half-pixel interpolation, which meets the requirements of real-time application for very high defination videos.展开更多
Today,backbone networks deploy a large number of devices and links.This is mainly due to both redundancy purposes for network service reliability,and resource over-dimensioning for maintaining quality of service durin...Today,backbone networks deploy a large number of devices and links.This is mainly due to both redundancy purposes for network service reliability,and resource over-dimensioning for maintaining quality of service during rush hours.Unfortunately,current routers do not have power management primitives,and have constant energy consumption independent of their actual workloads.How to implement a low power and multi-stage switch forwarding for IP lookup is a challenge in high-performance green routers design.A forwarding information base multi-stage mapping routing lookup architecture is presented,and the dynamic routing table mapping algorithm is designed to determine the optimal strides for building tree bitmap tries which lead the worst-case power consumption of the IP lookup engine to be minimized.Experimental results show that the application of reallife routing tables demonstrates that the proposed method could reduce power consumption of routing lookup by 30%.展开更多
Aimed at deficiencies in the development and implementation of Enterprise Service Architecture （ESA） software, an ESA software developing mode based on Model Driven Architecture （MDA） is put forward. This mode inc...Aimed at deficiencies in the development and implementation of Enterprise Service Architecture （ESA） software, an ESA software developing mode based on Model Driven Architecture （MDA） is put forward. This mode includes a calculation-independent model （ CIM ）, a platform-independent model （ PIM ）, a platform-specific model （PSM） and a code level. Based on this mode, the modeling architecture of CIM level is presented. CIM here includes a global model, a process model, an information model and an organization model. The modeling elements of global model, process recta-model, information recta-model and organization meta-model are defined in detail and the relationship between them is described. The reflecting relationship between these models is established as well.展开更多
Considering the coupled nonlinear Schr¨odinger system with multiply components, we provide a novel framework for constructing energy-preserving algorithms. In detail, based on the high order compact finite differ...Considering the coupled nonlinear Schr¨odinger system with multiply components, we provide a novel framework for constructing energy-preserving algorithms. In detail, based on the high order compact finite difference method, Fourier pseudospectral method and wavelet collocation method for spatial discretizations, a series of high accurate conservative algorithms are presented. The proposed algorithms can preserve the corresponding discrete charge and energy conservation laws exactly, which would guarantee their numerical stabilities during long time computations.Furthermore, several analogous multi-symplectic algorithms are constructed as comparison. Numerical experiments for the unstable plane waves will show the advantages of the proposed algorithms over long time and verify the theoretical analysis.展开更多
文摘大规模阵列天线技术(Massive Multiple Input Multiple Output,Massive MIMO)作为第五代移动通信(5G)的无线核心技术,实现了多波束空间覆盖增强,然而5G Massive MIMO的多波束射频高能耗、多波束碰撞和增加的干扰造会成5G网络能效下降,运营成本增高。基于3D数字地图、基站工程参数、终端上报的测量报告/最小化路测(Measurement Report/Minimization of Drive Test,MR/MDT)数据、用户/业务分布构建的三维数字孪生栅格,通过卷积长短期记忆(Convolutional Long Short Term Memory,Conv-LSTM)算法对栅格内的用户分布、业务分布进行分析和预测,通过Actor-Critic架构对5G波束配置和优化策略进行评估,实现不同场景、时段的5G波束最佳能效,智能适应5G网络潮汐效应,实现“网随业动”。
文摘The virtual network embedding/mapping problem is an important issue in network virtualization in Software-Defined Networking(SDN).It is mainly concerned with mapping virtual network requests,which could be a set of SDN flows,onto a shared substrate network automatically and efficiently.Previous researches mainly focus on developing heuristic algorithms for general topology virtual network.In practice however,the virtual network is usually generated with specific topology for specific purpose.Thus,it is a challenge to optimize the heuristic algorithms with these topology information.In order to deal with this problem,we propose a topology-cognitive algorithm framework,which is composed of a guiding principle for topology algorithm developing and a compound algorithm.The compound algorithm is composed of several subalgorithms,which are optimized for specific topologies.We develop star,tree,and ring topology algorithms as examples,other subalgorithms can be easily achieved following the same framework.The simulation results show that the topology-cognitive algorithm framework is effective in developing new topology algorithms,and the developed compound algorithm greatly enhances the performance of the Revenue/Cost(R/C) ratio and the Runtime than traditional heuristic algorithms for multi-topology virtual network embedding problem.
文摘In this paper, a fast half-pixel motion estimation algorithm and its corresponding hardware architecture is presented. Unlike three steps are needed in typical half-pixel motion estimation algorithm, the presented algorithm needs only two steps to obtain all the interpolated pixels of an entire 8x8 block. The proposed architecture works in a parallel way and is simulated by Modelsirn 6.5 SE, synthesized to the Xilinx Virtex4 XC4VLX15 FPGA device. The implementation results show that this architecture can achieve 190 MHz and 10 clock cycles are reduced to complete the entire interpolation process when compared with typical half-pixel interpolation, which meets the requirements of real-time application for very high defination videos.
基金Supported by the National High Technology Research and Development Programme of China(No.2008AA01A323,2009AA01A334)the National Basic Research Program of China(No.2007CB307102)
文摘Today,backbone networks deploy a large number of devices and links.This is mainly due to both redundancy purposes for network service reliability,and resource over-dimensioning for maintaining quality of service during rush hours.Unfortunately,current routers do not have power management primitives,and have constant energy consumption independent of their actual workloads.How to implement a low power and multi-stage switch forwarding for IP lookup is a challenge in high-performance green routers design.A forwarding information base multi-stage mapping routing lookup architecture is presented,and the dynamic routing table mapping algorithm is designed to determine the optimal strides for building tree bitmap tries which lead the worst-case power consumption of the IP lookup engine to be minimized.Experimental results show that the application of reallife routing tables demonstrates that the proposed method could reduce power consumption of routing lookup by 30%.
基金Sponsored by the National High Technology Research & Development Program of China(Grant No.2006AA04Z165,2006AA01Z167)the National Key Technology Research & Development Program of China(Grant No.2006BAH02A09)
文摘Aimed at deficiencies in the development and implementation of Enterprise Service Architecture （ESA） software, an ESA software developing mode based on Model Driven Architecture （MDA） is put forward. This mode includes a calculation-independent model （ CIM ）, a platform-independent model （ PIM ）, a platform-specific model （PSM） and a code level. Based on this mode, the modeling architecture of CIM level is presented. CIM here includes a global model, a process model, an information model and an organization model. The modeling elements of global model, process recta-model, information recta-model and organization meta-model are defined in detail and the relationship between them is described. The reflecting relationship between these models is established as well.
基金Supported by the National Natural Science Foundation of China under Grant No.91130013Hunan Provincial Innovation Foundation under Grant No.CX2012B010+1 种基金the Innovation Fund of National University of Defense Technology under Grant No.B120205the Open Foundation of State Key Laboratory
文摘Considering the coupled nonlinear Schr¨odinger system with multiply components, we provide a novel framework for constructing energy-preserving algorithms. In detail, based on the high order compact finite difference method, Fourier pseudospectral method and wavelet collocation method for spatial discretizations, a series of high accurate conservative algorithms are presented. The proposed algorithms can preserve the corresponding discrete charge and energy conservation laws exactly, which would guarantee their numerical stabilities during long time computations.Furthermore, several analogous multi-symplectic algorithms are constructed as comparison. Numerical experiments for the unstable plane waves will show the advantages of the proposed algorithms over long time and verify the theoretical analysis.
