期刊文献+
共找到474篇文章
< 1 2 24 >
每页显示 20 50 100
Priority-Aware Resource Allocation for VNF Deployment in Service Function Chains Based on Graph Reinforcement Learning
1
作者 Seyha Ros Seungwoo Kang +3 位作者 Taikuong Iv Inseok Song Prohim Tam Seokhoon Kim 《Computers, Materials & Continua》 2025年第5期1649-1665,共17页
Recently,Network Functions Virtualization(NFV)has become a critical resource for optimizing capability utilization in the 5G/B5G era.NFV decomposes the network resource paradigm,demonstrating the efficient utilization... Recently,Network Functions Virtualization(NFV)has become a critical resource for optimizing capability utilization in the 5G/B5G era.NFV decomposes the network resource paradigm,demonstrating the efficient utilization of Network Functions(NFs)to enable configurable service priorities and resource demands.Telecommunications Service Providers(TSPs)face challenges in network utilization,as the vast amounts of data generated by the Internet of Things(IoT)overwhelm existing infrastructures.IoT applications,which generate massive volumes of diverse data and require real-time communication,contribute to bottlenecks and congestion.In this context,Multiaccess Edge Computing(MEC)is employed to support resource and priority-aware IoT applications by implementing Virtual Network Function(VNF)sequences within Service Function Chaining(SFC).This paper proposes the use of Deep Reinforcement Learning(DRL)combined with Graph Neural Networks(GNN)to enhance network processing,performance,and resource pooling capabilities.GNN facilitates feature extraction through Message-Passing Neural Network(MPNN)mechanisms.Together with DRL,Deep Q-Networks(DQN)are utilized to dynamically allocate resources based on IoT network priorities and demands.Our focus is on minimizing delay times for VNF instance execution,ensuring effective resource placement,and allocation in SFC deployments,offering flexibility to adapt to real-time changes in priority and workload.Simulation results demonstrate that our proposed scheme outperforms reference models in terms of reward,delay,delivery,service drop ratios,and average completion ratios,proving its potential for IoT applications. 展开更多
关键词 Deep reinforcement learning graph neural network multi-access edge computing network functions virtualization software-defined networking
在线阅读 下载PDF
Service Function Chain Migration in LEO Satellite Networks 被引量:1
2
作者 Geng Yuhui Wang Niwei +5 位作者 Chen Xi Xu Xiaofan Zhou Changsheng Yang Junyi Xiao Zhenyu Cao Xianbin 《China Communications》 SCIE CSCD 2024年第3期247-259,共13页
With the advancements of software defined network(SDN)and network function virtualization(NFV),service function chain(SFC)placement becomes a crucial enabler for flexible resource scheduling in low earth orbit(LEO)sat... With the advancements of software defined network(SDN)and network function virtualization(NFV),service function chain(SFC)placement becomes a crucial enabler for flexible resource scheduling in low earth orbit(LEO)satellite networks.While due to the scarcity of bandwidth resources and dynamic topology of LEO satellites,the static SFC placement schemes may cause performance degradation,resource waste and even service failure.In this paper,we consider migration and establish an online migration model,especially considering the dynamic topology.Given the scarcity of bandwidth resources,the model aims to maximize the total number of accepted SFCs while incurring as little bandwidth cost of SFC transmission and migration as possible.Due to its NP-hardness,we propose a heuristic minimized dynamic SFC migration(MDSM)algorithm that only triggers the migration procedure when new SFCs are rejected.Simulation results demonstrate that MDSM achieves a performance close to the upper bound with lower complexity. 展开更多
关键词 network function virtualization(NFV) resource allocation satellite networks service function chain(SFC) SFC migration SFC placement soft-ware defined network(SDN)
在线阅读 下载PDF
SFC placement and dynamic resource allocation based on VNF performance-resource function and service requirement in cloud-edge environment
3
作者 HAN Yingchao MENG Weixiao FAN Wentao 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期906-921,共16页
With the continuous development of network func-tions virtualization(NFV)and software-defined networking(SDN)technologies and the explosive growth of network traffic,the requirement for computing resources in the netw... With the continuous development of network func-tions virtualization(NFV)and software-defined networking(SDN)technologies and the explosive growth of network traffic,the requirement for computing resources in the network has risen sharply.Due to the high cost of edge computing resources,coordinating the cloud and edge computing resources to improve the utilization efficiency of edge computing resources is still a considerable challenge.In this paper,we focus on optimiz-ing the placement of network services in cloud-edge environ-ments to maximize the efficiency.It is first proved that,in cloud-edge environments,placing one service function chain(SFC)integrally in the cloud or at the edge can improve the utilization efficiency of edge resources.Then a virtual network function(VNF)performance-resource(P-R)function is proposed to repre-sent the relationship between the VNF instance computing per-formance and the allocated computing resource.To select the SFCs that are most suitable to deploy at the edge,a VNF place-ment and resource allocation model is built to configure each VNF with its particular P-R function.Moreover,a heuristic recur-sive algorithm is designed called the recursive algorithm for max edge throughput(RMET)to solve the model.Through simula-tions on two scenarios,it is verified that RMET can improve the utilization efficiency of edge computing resources. 展开更多
关键词 cloud-edge environment virtual network function(vnf)performance-resource(P-R)function edge resource allo-cation
在线阅读 下载PDF
Using the Cooperative Game for Service Placement of Virtual Network Functions 被引量:1
4
作者 XIONG Gang HU Yuxiang +1 位作者 WANG Weiming WANG Lingqiang 《China Communications》 SCIE CSCD 2016年第S1期146-157,共12页
To address the issues that middleboxes as a fundamental part of today's networks are facing, Network Function Virtualization(NFV)has been recently proposed, which in essence asserts to migrate hardware-based middl... To address the issues that middleboxes as a fundamental part of today's networks are facing, Network Function Virtualization(NFV)has been recently proposed, which in essence asserts to migrate hardware-based middleboxes into software-based virtualized function entities.Due to the demands of virtual services placement in NFV network environment, this paper models the service amount placement problem involving with the resources allocation as a cooperative game and proposes the placement policy by Nash Bargaining Solution(NBS). Specifically,we first introduce the system overview and apply the rigorous cooperative game-theoretic guide to build the mathematical model, which can give consideration to both the responding efficiency of service requirements and the allocation fairness.Then a distributed algorithm corresponding to NBS is designed to achieve predictable network performance for virtual instances placement.Finally, with simulations under various scenarios,the results show that our placement approach can achieve high utilization of network through the analysis of evaluation metrics namely the satisfaction degree and fairness index. With the suitable demand amount of services, the average values of two metrics can reach above 90%. And by tuning the base placement, our solution can enable operators to flexibly balance the tradeoff between satisfaction and fairness of resourcessharing in service platforms. 展开更多
关键词 Middlebox GAME theory network function virtualIZATION SOFTWARE defined networkING
在线阅读 下载PDF
Efficiency-optimized 6G:A virtual network resource orchestration strategy by enhanced particle swarm optimization
5
作者 Sai Zou Junrui Wu +4 位作者 Haisheng Yu Wenyong Wang Lisheng Huang Wei Ni Yan Liu 《Digital Communications and Networks》 CSCD 2024年第5期1221-1233,共13页
The future Sixth-Generation (6G) wireless systems are expected to encounter emerging services with diverserequirements. In this paper, 6G network resource orchestration is optimized to support customized networkslicin... The future Sixth-Generation (6G) wireless systems are expected to encounter emerging services with diverserequirements. In this paper, 6G network resource orchestration is optimized to support customized networkslicing of services, and place network functions generated by heterogeneous devices into available resources.This is a combinatorial optimization problem that is solved by developing a Particle Swarm Optimization (PSO)based scheduling strategy with enhanced inertia weight, particle variation, and nonlinear learning factor, therebybalancing the local and global solutions and improving the convergence speed to globally near-optimal solutions.Simulations show that the method improves the convergence speed and the utilization of network resourcescompared with other variants of PSO. 展开更多
关键词 virtualIZATION network function orchestration network resource virtualized orchestration (NRVO) Particle swarm optimization(PSO)
在线阅读 下载PDF
基于VNF分集式备份机制的服务功能链部署方法
6
作者 赵季红 马健 +1 位作者 李倩雯 宁丽娟 《计算机科学》 北大核心 2025年第7期287-294,共8页
服务功能链(Service Function Chain, SFC)部署是实现网络服务灵活多样的关键技术,SFC可靠性是SFC部署工作中的重要指标。现有方法在提高SFC可靠性的同时造成了网络资源的浪费。为了平衡SFC可靠性和网络资源消耗,设计了一种VNF分集式备... 服务功能链(Service Function Chain, SFC)部署是实现网络服务灵活多样的关键技术,SFC可靠性是SFC部署工作中的重要指标。现有方法在提高SFC可靠性的同时造成了网络资源的浪费。为了平衡SFC可靠性和网络资源消耗,设计了一种VNF分集式备份(VNF Diversity Backup, VDB)机制,利用有限的网络资源改良SFC,将低可靠VNF实例拆分为两个副本实例,并对VNF副本实例进行交叉备份。在SFC部署阶段,提出了一种基于VDB机制的服务功能链部署方法,根据VDB机制的改良结果及网络拓扑属性构建多阶段图,采用基于Viterbi的动态规划算法在多阶段图中搜索最优部署路径。此外,引入评价指标备份性价比来衡量SFC可靠性和网络资源消耗的平衡效果。仿真结果表明,所提方法有效地平衡了可靠性和网络资源消耗,并且优化了传输时延。 展开更多
关键词 服务功能链 网络功能虚拟化 服务功能部署 可靠性 时延
在线阅读 下载PDF
Virtualizing Network and Service Functions: Impact on ICT Transformation and Standardization 被引量:1
7
作者 Bhumip Khasnabish Jie Hu Ghazanfar Ali 《ZTE Communications》 2013年第4期40-46,共7页
Virtualization of network/service functions means time sharing network/service(and affiliated)resources in a hyper speed manner.The concept of time sharing was popularized in the 1970s with mainframe computing.The s... Virtualization of network/service functions means time sharing network/service(and affiliated)resources in a hyper speed manner.The concept of time sharing was popularized in the 1970s with mainframe computing.The same concept has recently resurfaced under the guise of cloud computing and virtualized computing.Although cloud computing was originally used in IT for server virtualization,the ICT industry is taking a new look at virtualization.This paradigm shift is shaking up the computing,storage,networking,and ser vice industries.The hope is that virtualizing and automating configuration and service management/orchestration will save both capes and opex for network transformation.A complimentary trend is the separation(over an open interface)of control and transmission.This is commonly referred to as software defined networking(SDN).This paper reviews trends in network/service functions,efforts to standardize these functions,and required management and orchestration. 展开更多
关键词 network function virtualization(NFV) and chaining service function virtualization(SFV) and chaining network virtualization overlay(NVO) software defined networking(SDN) networking economics
在线阅读 下载PDF
Network Function Virtualization Technology:Progress and Standardization
8
作者 Huiling Zhao Yunpeng Xie Fan Shi 《ZTE Communications》 2014年第2期3-7,共5页
Network innovation and business transformation are both necessary for telecom operators to adapt to new situations, but operators face challenges in terms of network bearer complexity, business centralization, and IT/... Network innovation and business transformation are both necessary for telecom operators to adapt to new situations, but operators face challenges in terms of network bearer complexity, business centralization, and IT/CT integration. Network function virtualization (NFV) may inspire new development ideas, but many doubts still exist within industry, especially about how to introduce NFV into an operator' s network. This article describes the latest progress in NFV standardization, NFV requirements and hot technology issues, and typical NFV applications in an operator networks. 展开更多
关键词 network functions virtualization (NFV) overlay network virtual extensible LAN (VXLAN) service chaining
在线阅读 下载PDF
Optimize the Deployment and Integration for Multicast-Oriented Virtual Network Function Tree
9
作者 Ying Chang Hongxue Yang Qinghua Zhu 《Journal of Beijing Institute of Technology》 EI CAS 2022年第5期513-523,共11页
Due to the development of network technology,the number of users is increasing rapidly,and the demand for emerging multicast services is becoming more and more abundant,traffic data is increasing day by day,network no... Due to the development of network technology,the number of users is increasing rapidly,and the demand for emerging multicast services is becoming more and more abundant,traffic data is increasing day by day,network nodes are becoming denser,network topology is becoming more complex,and operators’equipment operation and maintenance costs are increasing.Network functions virtualization multicast issues include building a traffic forwarding topology,deploying the required functions,and directing traffic.Combining the two is still a problem to be studied in depth at present,and this paper proposes a two-stage solution where the decisions of these two stages are interdependent.Specifically,this paper decouples multicast traffic forwarding and function delivery.The minimum spanning tree of traffic forwarding is constructed by Steiner tree,and the traffic forwarding is realized by Viterbi-algorithm.Use a general topology network to examine network cost and service performance.Simulation results show that this method can reduce overhead and delay and optimize user experience. 展开更多
关键词 MULTICAST service function chain(SFC) network functions virtualization(NFV) software defined network(SDN) Viterbi-algorithm
在线阅读 下载PDF
Enhanced Reliability in Network Function Virtualization by Hybrid Hexagon-Cost Efficient Algorithm
10
作者 D.Jeyakumar C.Rajabhushanam 《Computer Systems Science & Engineering》 SCIE EI 2022年第12期1131-1144,共14页
In this,communication world, the Network Function Virtualization concept is utilized for many businesses, small services to virtualize the network nodefunction and to build a block that may connect the chain, communic... In this,communication world, the Network Function Virtualization concept is utilized for many businesses, small services to virtualize the network nodefunction and to build a block that may connect the chain, communication services.Mainly, Virtualized Network Function Forwarding Graph (VNF-FG) has beenused to define the connection between the VNF and to give the best end-to-endservices. In the existing method, VNF mapping and backup VNF were proposedbut there was no profit and reliability improvement of the backup and mapping ofthe primary VNF. As a consequence, this paper offers a Hybrid Hexagon-CostEfficient algorithm for determining the best VNF among multiple VNF and backing up the best VNF, lowering backup costs while increasing dependability. TheVNF is chosen based on the highest cost-aware important measure (CIM) rate,which is used to assess the relevance of the VNF forwarding graph.To achieveoptimal cost-efficiency, VNF with the maximum CIM is selected. After the selection process, updating is processed by three steps which include one backup VNFfrom one SFC, two backup VNF from one Service Function Chain (SFC),and twobackup VNF from different SFC. Finally, this proposed method is compared withCERA, MinCost, MaxRbyInr based on backup cost, number of used PN nodes,SFC request utility, and latency. The simulation result shows that the proposedmethod cuts down the backup cost and computation time by 57% and 45% compared with the CER scheme and improves the cost-efficiency. As a result, this proposed system achieves less backup cost, high reliability, and low timeconsumption which can improve the Virtualized Network Function operation. 展开更多
关键词 network function virtualized(NFV) hybrid hexagon-cost efficient algorithm(HH-CE) cost-aware important measure(CIM) RELIABILITY network services
在线阅读 下载PDF
Space Network Emulation System Based on a User-Space Network Stack
11
作者 LEI Jianzhe ZHAO Kanglian +1 位作者 HOU Dongxu ZHOU Fenlin 《ZTE Communications》 2025年第2期11-19,共9页
This paper presents a space network emulation system based on a user-space network stack named Nos to solve space networks'unique architecture and routing issues and kernel stacks'inefficiency and development ... This paper presents a space network emulation system based on a user-space network stack named Nos to solve space networks'unique architecture and routing issues and kernel stacks'inefficiency and development complexity.Our low Earth orbit satellite scenario emulation verifies the dynamic routing function of the protocol stack.The proposed system uses technologies like Open vSwitch(OVS)and traffic control(TC)to emulate the space network's highly dynamic topology and time-varying link characteristics.The emulation results demonstrate the system's high reliability,and the user-space network stack reduces development complexity and debugging difficulty,providing convenience for the development of space network protocols and network functions. 展开更多
关键词 network emulation space network user-space network stack network function virtualization
在线阅读 下载PDF
Effective Edge-Cloud Interplay for NFV-Based Optical Metro-Access Networks Supporting IoT Services
12
作者 Jin Feiming Zhang Yukun +2 位作者 Li Hanxue Amr Tolba Zhang Tiantian 《China Communications》 2025年第4期117-128,共12页
In optical metro-access networks,Access Points(APs)and Data Centers(DCs)are located on the fiber ring.In the cloud-centric solution,a large number of Internet of Things(IoT)data pose an enormous burden on DCs,so the V... In optical metro-access networks,Access Points(APs)and Data Centers(DCs)are located on the fiber ring.In the cloud-centric solution,a large number of Internet of Things(IoT)data pose an enormous burden on DCs,so the Virtual Machines(VMs)cannot be successfully launched due to the server overload.In addition,transferring the data from the AP to the remote DC may cause an undesirable delivery delay.For this end,we propose a promising solution considering the interplay between the cloud DC and edge APs.More specifically,bringing the partial capability of computing in APs close to things can reduce the pressure of DCs while guaranteeing the expected Quality of Service(QoS).In this work,when the cloud DC resource becomes limited,especially for delay sensitive but not computing-dependent IoT applications,we degrade their VMs and migrate them to edge APs instead of the remote DC.To avoid excessive VM degradation and computing offloading,we derive appropriate VM degradation coefficients based on classic microeconomic theory.Simulation results demonstrate that our algorithms improve the service providers'utility with the ratio from 34%to 89%over traditional cloud-centric solutions. 展开更多
关键词 computing offloading edge-cloud interplay network function virtualization optical metroaccess network service degradability
在线阅读 下载PDF
An Approach for Network Function Combination Based on Least Busy Placement Algorithm 被引量:3
13
作者 XIE Lijun JIANG Yiming +2 位作者 WANG Binqiang XIONG Gang CHENG Guozhen 《China Communications》 SCIE CSCD 2016年第S1期167-176,共10页
Recently, integrating Softwaredefined networking(SDN) and network functions virtualization(NFV) are proposed to address the issue that difficulty and cost of hardwarebased and proprietary middleboxes management. Howev... Recently, integrating Softwaredefined networking(SDN) and network functions virtualization(NFV) are proposed to address the issue that difficulty and cost of hardwarebased and proprietary middleboxes management. However, it lacks of a framework that orchestrates network functions to service chain in the network cooperatively. In this paper, we propose a function combination framework that can dynamically adapt the network based on the integration NFV and SDN. There are two main contributions in this paper. First, the function combination framework based on the integration of SDN and NFV is proposed to address the function combination issue, including the architecture of Service Deliver Network, the port types representing traffic directions and the explanation of terms. Second, we formulate the issue of load balance of function combination as the model minimizing the standard deviations of all servers' loads and satisfying the demand of performance and limit of resource. The least busy placement algorithm is introduced to approach optimal solution of the problem. Finally, experimental results demonstrate that the proposed method can combine functions in an efficient and scalable way and ensure the load balance of the network. 展开更多
关键词 software-defined networkING network functions virtualIZATION load BALANCE least BUSY PLACEMENT ALGORITHM contribution degree
在线阅读 下载PDF
Virtualization-enabled dynamic functional split and resource mapping in optical data center networks[Invited]
14
作者 Bo Tian Shanting Hu +5 位作者 Qi Zhang Xiaofei Huang Lei Zhu Huan Chang Xiaolong Pan Xiangjun Xin 《Chinese Optics Letters》 2025年第5期1-8,共8页
The heterogeneity of applications and their divergent resource requirements lead to uneven traffic distribution and imbalanced resource utilization across data center networks(DCNs).We propose a fine-grained baseband ... The heterogeneity of applications and their divergent resource requirements lead to uneven traffic distribution and imbalanced resource utilization across data center networks(DCNs).We propose a fine-grained baseband function reallocation scheme in heterogeneous optical switching-based DCNs.A deep reinforcement learning-based functional split and resource mapping approach(DRL-BFM)is proposed to maximize throughput in high-load server racks by implementing load balancing in DCNs.The results demonstrate that DRL-BFM improves the throughput by 20.8%,22.8%,and 29.8%on average compared to existing algorithms under different computational capacities,bandwidth constraints,and latency conditions,respectively. 展开更多
关键词 virtualIZATION resource mapping functional split optical data center network
原文传递
可靠性感知的边缘计算VNF实例放置 被引量:1
15
作者 梁晶语 马博闻 黄霁崴 《计算机科学》 CSCD 北大核心 2024年第S01期759-764,共6页
为了解决日益增长的延迟敏感型应用程序和用户需求与计算资源受限的冲突,移动边缘计算(Mobile Edge Computing,MEC)已经成为一种很有前途的计算范式。服务提供商通过在边缘环境中部署虚拟化网络功能(Virtual Network Functions,VNF),为... 为了解决日益增长的延迟敏感型应用程序和用户需求与计算资源受限的冲突,移动边缘计算(Mobile Edge Computing,MEC)已经成为一种很有前途的计算范式。服务提供商通过在边缘环境中部署虚拟化网络功能(Virtual Network Functions,VNF),为用户提供更加高效和可扩展性的服务供应链(Service Function Chain,SFC)来满足用户请求。若在提供服务过程中出现不可靠的服务或严重的服务失败,可能导致用户的巨大损失,所以网络服务提供商必须保证提供持续可靠的服务。针对该问题,考虑了边缘服务器的可靠性,利用计算统一设备架构(Computational Unified Device Architecture,CUDA)支持的门控循环单元(Gate Recurrent Unite,GRU)来预测VNF实例是否可用,通过预测结果,提前对VNF进行备份,避免了过度冗余备份造成的成本过高问题。考虑服务器的存储资源有限,提出了基于VNF实例可用性的放置(RVP)算法,优化服务提供商的成本。最后对提出的算法进行了性能评估,实验结果验证了RVP算法的优越性。 展开更多
关键词 边缘计算 服务供应链 虚拟化网络功能 可靠性 vnf实例放置
在线阅读 下载PDF
Security Monitoring and Management for the Network Services in the Orchestration of SDN-NFV Environment Using Machine Learning Techniques 被引量:2
16
作者 Nasser Alshammari Shumaila Shahzadi +7 位作者 Saad Awadh Alanazi Shahid Naseem Muhammad Anwar Madallah Alruwaili Muhammad Rizwan Abid Omar Alruwaili Ahmed Alsayat Fahad Ahmad 《Computer Systems Science & Engineering》 2024年第2期363-394,共32页
Software Defined Network(SDN)and Network Function Virtualization(NFV)technology promote several benefits to network operators,including reduced maintenance costs,increased network operational performance,simplified ne... Software Defined Network(SDN)and Network Function Virtualization(NFV)technology promote several benefits to network operators,including reduced maintenance costs,increased network operational performance,simplified network lifecycle,and policies management.Network vulnerabilities try to modify services provided by Network Function Virtualization MANagement and Orchestration(NFV MANO),and malicious attacks in different scenarios disrupt the NFV Orchestrator(NFVO)and Virtualized Infrastructure Manager(VIM)lifecycle management related to network services or individual Virtualized Network Function(VNF).This paper proposes an anomaly detection mechanism that monitors threats in NFV MANO and manages promptly and adaptively to implement and handle security functions in order to enhance the quality of experience for end users.An anomaly detector investigates these identified risks and provides secure network services.It enables virtual network security functions and identifies anomalies in Kubernetes(a cloud-based platform).For training and testing purpose of the proposed approach,an intrusion-containing dataset is used that hold multiple malicious activities like a Smurf,Neptune,Teardrop,Pod,Land,IPsweep,etc.,categorized as Probing(Prob),Denial of Service(DoS),User to Root(U2R),and Remote to User(R2L)attacks.An anomaly detector is anticipated with the capabilities of a Machine Learning(ML)technique,making use of supervised learning techniques like Logistic Regression(LR),Support Vector Machine(SVM),Random Forest(RF),Naïve Bayes(NB),and Extreme Gradient Boosting(XGBoost).The proposed framework has been evaluated by deploying the identified ML algorithm on a Jupyter notebook in Kubeflow to simulate Kubernetes for validation purposes.RF classifier has shown better outcomes(99.90%accuracy)than other classifiers in detecting anomalies/intrusions in the containerized environment. 展开更多
关键词 Software defined network network function virtualization network function virtualization management and orchestration virtual infrastructure manager virtual network function Kubernetes Kubectl artificial intelligence machine learning
在线阅读 下载PDF
Epileptic brain network mechanisms and neuroimaging techniques for the brain network 被引量:1
17
作者 Yi Guo Zhonghua Lin +1 位作者 Zhen Fan Xin Tian 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第12期2637-2648,共12页
Epilepsy can be defined as a dysfunction of the brain network,and each type of epilepsy involves different brain-network changes that are implicated diffe rently in the control and propagation of interictal or ictal d... Epilepsy can be defined as a dysfunction of the brain network,and each type of epilepsy involves different brain-network changes that are implicated diffe rently in the control and propagation of interictal or ictal discharges.Gaining more detailed information on brain network alterations can help us to further understand the mechanisms of epilepsy and pave the way for brain network-based precise therapeutic approaches in clinical practice.An increasing number of advanced neuroimaging techniques and electrophysiological techniques such as diffusion tensor imaging-based fiber tra ctography,diffusion kurtosis imaging-based fiber tractography,fiber ball imagingbased tra ctography,electroencephalography,functional magnetic resonance imaging,magnetoencephalography,positron emission tomography,molecular imaging,and functional ultrasound imaging have been extensively used to delineate epileptic networks.In this review,we summarize the relevant neuroimaging and neuroelectrophysiological techniques for assessing structural and functional brain networks in patients with epilepsy,and extensively analyze the imaging mechanisms,advantages,limitations,and clinical application ranges of each technique.A greater focus on emerging advanced technologies,new data analysis software,a combination of multiple techniques,and the construction of personalized virtual epilepsy models can provide a theoretical basis to better understand the brain network mechanisms of epilepsy and make surgical decisions. 展开更多
关键词 electrophysiological techniques EPILEPSY functional brain network functional magnetic resonance imaging functional near-infrared spectroscopy machine leaning molecular imaging neuroimaging techniques structural brain network virtual epileptic models
暂未订购
基于深度强化学习的能源高效VNF放置和链接方法
18
作者 赵耀鹏 徐九韵 脱颖超 《计算机系统应用》 2024年第7期230-238,共9页
网络功能虚拟化(NFV)技术的出现使得网络功能由虚拟网络功能(VNF)提供,从而提高网络的灵活性,可扩展性和成本效益.然而,NFV面临一个重要挑战是,如何有效地将VNF放置不同的网络位置并链接起来引导流量,同时最大限度减少能源消耗.此外,面... 网络功能虚拟化(NFV)技术的出现使得网络功能由虚拟网络功能(VNF)提供,从而提高网络的灵活性,可扩展性和成本效益.然而,NFV面临一个重要挑战是,如何有效地将VNF放置不同的网络位置并链接起来引导流量,同时最大限度减少能源消耗.此外,面对网络服务质量要求,提高服务接受率对于网络性能也是至关重要的.为了解决这些问题,本文研究了NFV中的VNF放置和链接(VNFPC),以最大化服务接受率同时权衡优化能源消耗.因此,在NFV中设计了一种基于Actor-Critic深度强化学习(DRL)的能源高效的VNFPC方法,称为ACDRLVNFPC.该方法应用了适应性共享方案,通过在多服务之间共享同类型VNF和多VNF共享同一个服务器来实现节能.实验结果表明,提出的算法有效权衡了能耗和服务接受率,并且,在执行时间方面也得到了优化.与基准算法相比,ACDRL-VNFPC在服务接受率,能耗和执行时间方面性能分别提高了2.39%,14.93%和16.16%. 展开更多
关键词 网络功能虚拟化 虚拟网络功能放置 服务功能链 能源高效
在线阅读 下载PDF
SFC Design and VNF Placement Based on Traffic Volume Scaling and VNF Dependency in 5G Networks
19
作者 Zhihao Zeng Zixiang Xia +1 位作者 Xiaoning Zhang Yexiao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第3期1791-1814,共24页
The development of Fifth-Generation(5G)mobile communication technology has remarkably promoted the spread of the Internet of Things(IoT)applications.As a promising paradigm for IoT,edge computing can process the amoun... The development of Fifth-Generation(5G)mobile communication technology has remarkably promoted the spread of the Internet of Things(IoT)applications.As a promising paradigm for IoT,edge computing can process the amount of data generated by mobile intelligent devices in less time response.Network Function Virtualization(NFV)that decouples network functions from dedicated hardware is an important architecture to implement edge computing,deploying heterogeneous Virtual Network Functions(VNF)(such as computer vision,natural language processing,intelligent control,etc.)on the edge service nodes.With the NFV MANO(Management and Orchestration)framework,a Service Function Chain(SFC)that contains a set of ordered VNFs can be constructed and placed in the network to offer a customized network service.However,the procedure of NFV orchestration faces a technical challenge in minimizing the network cost of VNF placement due to the complexity of the changing effect of traffic volume and the dependency on theVNFrelationship.To this end,we jointly optimize SFC design and VNF placement to minimize resource cost while taking account of VNF dependency and traffic volume scaling.First,the problem is formulated as an Integer Linear Programming(ILP)model and proved NPhard by reduction from Hamiltonian Cycle problem.Then we proposed an efficient heuristic algorithm called Traffic Aware and Interdependent VNF Placement(TAIVP)to solve the problem.Compared with the benchmark algorithms,emulation results show that our algorithm can reduce network cost by 10.2%and increase service request acceptance rate by 7.6%on average. 展开更多
关键词 network function virtualization virtual network function service function chain resource allocation routing
在线阅读 下载PDF
Adaptive Partial Task Offloading and Virtual Resource Placement in SDN/NFV-Based Network Softwarization
20
作者 Prohim Tam Sa Math Seokhoon Kim 《Computer Systems Science & Engineering》 SCIE EI 2023年第5期2141-2154,共14页
Edge intelligence brings the deployment of applied deep learning(DL)models in edge computing systems to alleviate the core backbone network congestions.The setup of programmable software-defined networking(SDN)control... Edge intelligence brings the deployment of applied deep learning(DL)models in edge computing systems to alleviate the core backbone network congestions.The setup of programmable software-defined networking(SDN)control and elastic virtual computing resources within network functions virtualization(NFV)are cooperative for enhancing the applicability of intelligent edge softwarization.To offer advancement for multi-dimensional model task offloading in edge networks with SDN/NFV-based control softwarization,this study proposes a DL mechanism to recommend the optimal edge node selection with primary features of congestion windows,link delays,and allocatable bandwidth capacities.Adaptive partial task offloading policy considered the DL-based recommendation to modify efficient virtual resource placement for minimizing the completion time and termination drop ratio.The optimization problem of resource placement is tackled by a deep reinforcement learning(DRL)-based policy following the Markov decision process(MDP).The agent observes the state spaces and applies value-maximized action of available computation resources and adjustable resource allocation steps.The reward formulation primarily considers taskrequired computing resources and action-applied allocation properties.With defined policies of resource determination,the orchestration procedure is configured within each virtual network function(VNF)descriptor using topology and orchestration specification for cloud applications(TOSCA)by specifying the allocated properties.The simulation for the control rule installation is conducted using Mininet and Ryu SDN controller.Average delay and task delivery/drop ratios are used as the key performance metrics. 展开更多
关键词 Deep learning partial task offloading software-defined networking virtual machine virtual network functions
在线阅读 下载PDF
上一页 1 2 24 下一页 到第
使用帮助 返回顶部