scholarly journals Dynamic Repair and Robust Optimization of Complex Networks

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Pengtao Zhang ◽  
Peng Bai ◽  
Chaoqi Fu ◽  
Shanshan Li
Keyword(s):  
Energy Transfer ◽  
Repair Process ◽  
Recovery Efficiency ◽  
Repair Strategy ◽  
Coupling Structure ◽  
Secondary Failure ◽  
Fundamental Reason ◽  
Network Functions ◽  
The Impact ◽  
Failure Node

Network repair is indispensable for maintaining network security. Conventional static repair is relatively inefficient. In this study, by considering the energy transfer between nodes, a dynamic repair model was established. The fundamental reason for the secondary failure of repaired nodes during the dynamic repair process is the coupling structure of failure networks. A dynamic repair strategy was proposed that can effectively prevent the secondary failure of repair nodes influenced by energy during repair and can cause the redundant capacity of repair nodes to be used reasonably. By turning off the energy transfer function of the link to control the excessive flow of energy into the repair node to avoid the occurrence of secondary failure; on the other hand, by sharing part of the load of the failure node, realize the rational use of the redundant capacity of the repair node to reduce the impact of the failure node on the overall function of the network. The proposed strategy mitigated the effect of failure nodes on network functions and substantially improved the recovery efficiency of network functions. Furthermore, redundant edges, behaving as energy redundant links in a network structure, can considerably improve the robustness of the network by optimizing the removal of redundant edges. Dynamic repair is not only an efficient repair method but also a highly flexible choice for network repair.

scholarly journals Socialization, Connection, and The Structure/Agency Gap: A Specification of The Impact of Networks on Participation in Social Movements

2001 ◽  
Vol 6 (2) ◽  
pp. 173-192 ◽  
Author(s):  
Florence Passy
Keyword(s):  
Social Networks ◽  
Social Movement ◽  
Political Issue ◽  
Individual Preferences ◽  
Life History Data ◽  
Network Functions ◽  
Structural Connection ◽  
Movement Participation ◽  
The Impact

While numerous studies stress the crucial role of networks for social movement participation, they generally do not specify how networks affect individual behaviors. This article clarifies the role of social networks for individual social movement participation. It argues that networks perform three fundamental functions in the process leading to participation and that they intervene at different moments along this process. First, networks socialize and build individual identities—a socialization function. Second, they offer participation opportunities to individuals who are culturally sensitive to a specific political issue—a structural-connection function. Third, they shape individual preferences before individuals decide to join a move-ment—a decision-shaping function. These network functions allow us to disentangle the mechanisms at work in the process of participation. They also integrate structural and rationalist theories, which are often considered opposing explanations of individual movement participation. This article presents several hypotheses about these network functions, and uses both quantitative (survey) and qualitative (life history) data of participation in the Berne Declaration SMO to examine them.

scholarly journals Path Mapping Approach for Network Function Virtualization Resource Allocation with Network Function Decomposition Support

Symmetry ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1173 ◽  
Author(s):  
Basheer Raddwan ◽  
Khalil AL-Wagih ◽  
Ibrahim A. Al-Baltah ◽  
Mohamed A. Alrshah ◽  
Mohammed A. Al-Maqri
Keyword(s):  
Resource Allocation ◽  
Execution Time ◽  
Service Providers ◽  
Virtual Network ◽  
Network Function Virtualization ◽  
Network Function ◽  
Function Decomposition ◽  
Mapping Approach ◽  
Network Functions ◽  
The Impact

Recently, Network Function Virtualization (NFV) and Software Defined Networking (SDN) have attracted many mobile operators. For the flexible deployment of Network Functions (NFs) in an NFV environment, NF decompositions and control/user plane separation have been introduced in the literature. That is to map traditional functions into their corresponding Virtual Network Functions (VNFs). This mapping requires the NFV Resource Allocation (NFV-RA) for multi-path service graphs with a high number of virtual nodes and links, which is a complex NP-hard problem that inherited its complexity from the Virtual Network Embedding (VNE). This paper proposes a new path mapping approach to solving the NFV-RA problem for decomposed Network Service Chains (NSCs). The proposed solution has symmetrically considered optimizing an average embedding cost with an enhancement on average execution time. The proposed approach has been compared to two other existing schemes using 6 and 16 scenarios of short and long simulation runs, respectively. The impact of the number of nodes, links and paths of the service requests on the proposed scheme has been studied by solving more than 122,000 service requests. The proposed Integer Linear Programming (ILP) and heuristic schemes have reduced the execution time up to 39.58% and 6.42% compared to existing ILP and heuristic schemes, respectively. Moreover, the proposed schemes have also reduced the average embedding cost and increased the profit for the service providers.

scholarly journals Impact of the Maximum Number of Switching Reconfigurations on the Cost Saving in Network Function Virtualization Environments with Elastic Optical Interconnection

2019 ◽  
Vol 9 (23) ◽  
pp. 5167
Author(s):  
Vincenzo Eramo ◽  
Francesco G. Lavacca ◽  
Tiziana Catena
Keyword(s):  
Computational Complexity ◽  
Cost Saving ◽  
Virtual Machines ◽  
New Technology ◽  
Network Function Virtualization ◽  
Optical Interconnection ◽  
Network Function ◽  
Network Functions ◽  
The Cost ◽  
The Impact

Network Function Virtualization is based on the virtualization of the network functions and it is a new technology allowing for a more flexible allocation of cloud and bandwidth resources. In order to employ the flexibility of the technology and to adapt its use according to the traffic variation, reconfigurations of the cloud and bandwidth resources are needed by means of both migration of the Virtual Machines executing the network functions and reconfiguration of circuits interconnecting the Virtual Machines. The objective of the paper is to study the impact of the maximum number of switch reconfigurations on the cost saving that the Networking Function Virtualization technology allows us to achieve. The problem is studied in the case of a scenario with an elastic optical network interconnecting datacenters in which the Virtual Machines are executed. The problem can be formulated as an Integer Linear Programming one introducing a constraint on the maximum number of switch reconfigurations but due to its computational complexity we propose a low computational complexity heuristic allowing for results close to the optimization ones. The results show how the limitation on the number of possible reconfigurations has to be taken into account to evaluate the effectiveness in terms of cost saving that the Virtual Machine migrations in Network Function Virtualization environment allows us to achieve.

scholarly journals Balanced excitation and inhibition are required for high-capacity, noise-robust neuronal selectivity

2017 ◽  
Vol 114 (44) ◽  
pp. E9366-E9375 ◽  
Author(s):  
Ran Rubin ◽  
L. F. Abbott ◽  
Haim Sompolinsky
Keyword(s):  
High Capacity ◽  
Distinct Type ◽  
Spatiotemporal Variability ◽  
Inhibitory Synapses ◽  
Multiple Sources ◽  
Output Noise ◽  
Network Functions ◽  
Noise Robust ◽  
The Impact ◽  
Balanced Networks

Neurons and networks in the cerebral cortex must operate reliably despite multiple sources of noise. To evaluate the impact of both input and output noise, we determine the robustness of single-neuron stimulus selective responses, as well as the robustness of attractor states of networks of neurons performing memory tasks. We find that robustness to output noise requires synaptic connections to be in a balanced regime in which excitation and inhibition are strong and largely cancel each other. We evaluate the conditions required for this regime to exist and determine the properties of networks operating within it. A plausible synaptic plasticity rule for learning that balances weight configurations is presented. Our theory predicts an optimal ratio of the number of excitatory and inhibitory synapses for maximizing the encoding capacity of balanced networks for given statistics of afferent activations. Previous work has shown that balanced networks amplify spatiotemporal variability and account for observed asynchronous irregular states. Here we present a distinct type of balanced network that amplifies small changes in the impinging signals and emerges automatically from learning to perform neuronal and network functions robustly.

scholarly journals Network Function Virtualization over Cloud-Cloud Computing as Business Continuity Solution

2021 ◽  
Author(s):  
Wagdy Anis Aziz ◽  
Eduard Babulak ◽  
David Al-Dabass
Keyword(s):  
Cloud Computing ◽  
Cost Model ◽  
Cloud Service ◽  
Network Function Virtualization ◽  
Business Continuity ◽  
Service Availability ◽  
Model Network ◽  
Network Function ◽  
Network Functions ◽  
The Impact

Cloud computing provides resources by using virtualization technology and a pay-as-you-go cost model. Network Functions Virtualization (NFV) is a concept, which promises to grant network operators the required flexibility to quickly develop and provision new network functions and services, which can be hosted in the cloud. However, cloud computing is subject to failures which emphasizes the need to address user’s availability requirements. Availability refers to the cloud uptime and the cloud capability to operate continuously. Providing highly available services in cloud computing is essential for maintaining customer confidence and satisfaction and preventing revenue losses. Different techniques can be implemented to increase the system’s availability and assure business continuity. This chapter covers cloud computing as business continuity solution and cloud service availability. This chapter also covers the causes of service unavailability and the impact due to service unavailability. Further, this chapter covers various ways to achieve the required cloud service availability.

A global electronic imaging and distribution system employing a computer network

1994 ◽  
Vol 52 ◽  
pp. 456-457
Author(s):  
Dennis J. Palatini
Keyword(s):  
Distribution System ◽  
Electronic Mail ◽  
Computer Network ◽  
Local Area Network ◽  
Silver Halide ◽  
Local Area ◽  
Area Network ◽  
Intelligent Network ◽  
Electronic Imaging ◽  
The Impact

BACKGROUND Conventional silver halide photography has been used successfully for over one hundred years and remains unsurpassed in quality and fidelity for recording and displaying image information. During the past decade the impact of computers on all fields of information sciences has been both profound and widespread. Recently, personal computers have been acknowledged as effective and efficient tools for assuming the role of conventional photography. A simple, rapid, and well-established system was in place at Unilever to distribute the written word (electronic mail), however, no system was available to manage and distribute scientific images. An inordinate amount of time was elapsing between the time images were formed and when our colleagues viewed them Also, imaging scientists were spending an excessive amount of time in the darkroom developing and printing images. The Unilever Global Electronic Imaging and Distribution System was developed to address these growing problems.SYSTEM CONFIGURATION The configuration of the Unilever System is depicted in Figure 1. It consists of a restricted LAN (local area network) which isolates imaging traffic for optimal speed. This communication network still allows communication to the site LAN via the hub and Ethernet backbone and vice versa. The hub is an intelligent network controller that isolates network traffic.

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