摘要 :
Meso-scale structural analysis, like core decomposition has uncovered groups of nodes that play important roles in the underlying complex systems. The existing core decomposition approaches generally focus on node properties like ...
展开
Meso-scale structural analysis, like core decomposition has uncovered groups of nodes that play important roles in the underlying complex systems. The existing core decomposition approaches generally focus on node properties like degree and strength. The node centric approaches can only capture a limited information about the local neighborhood topology. In the present work, we propose a group density based core analysis approach that overcome the drawbacks of the node centric approaches. The proposed algorithmic approach focuses on weight density, cohesiveness, and stability of a substructure. The method also assigns an unique score to every node that rank the nodes based on their degree of core-ness. To determine the correctness of the proposed method, we propose a synthetic benchmark with planted core structure. A performance test on the null model is carried out using a weighted lattice without core structures. We further test the stability of the approach against random noise. The experimental results prove the superiority of our algorithm over the state-of-the-arts. We finally analyze the core structures of several popular weighted network models and real life weighted networks. The experimental results reveal important node ranking and hierarchical organization of the complex networks, which give us better insight about the underlying systems.
收起
摘要 :
Previous report describes that the AKARI V.2.0 network can never be used for business because of its poor reliability and security; both of which are due to various limitations. The author's solution, installing gate device (i.e.,...
展开
Previous report describes that the AKARI V.2.0 network can never be used for business because of its poor reliability and security; both of which are due to various limitations. The author's solution, installing gate device (i.e., end node) between overlay router and routing node, clearly delineates the business boundary between service providers and communication carrier. The improved AKARI V.2.0 network uses the framework of "Service over core network", where core network is the AKARI common network. On services installed onto the improved AKARI.V.2.0 network, this report describes: (1) Independency of terminal addresses among services, (2) how to deal with communication quality for multiple services, (3) how to communicate between two services using both liaison server and liaison VPN tunnel between, for example, a mobile service and cloud computing service, (4) specification plan of some core network functions for services, and so on.
收起
摘要 :
Virtualization technology can greatly improve the efficiency of the networks by allowing the virtual optical networks to share the resources of the physical networks. However, it will face some challenges, such as finding the effi...
展开
Virtualization technology can greatly improve the efficiency of the networks by allowing the virtual optical networks to share the resources of the physical networks. However, it will face some challenges, such as finding the efficient strategies for virtual nodes mapping, virtual links mapping and spectrum assignment. It is even more complex and challenging when the physical elastic optical networks using multi-core fibers. To tackle these challenges, we establish a constrained optimization model to determine the optimal schemes of optical network mapping, core allocation and spectrum assignment. To solve the model efficiently, tailor-made encoding scheme, crossover and mutation operators are designed. Based on these, an efficient genetic algorithm is proposed to obtain the optimal schemes of the virtual nodes mapping, virtual links mapping, core allocation. The simulation experiments are conducted on three widely used networks, and the experimental results show the effectiveness of the proposed model and algorithm. (C) 2017 Elsevier B.V. All rights reserved.
收起
摘要 :
Core percolation, as a fundamental structural transition resulting from preserving core nodes in the network, is crucial in the network controllability and robustness. Prior art has investigated single, non-interacting complex net...
展开
Core percolation, as a fundamental structural transition resulting from preserving core nodes in the network, is crucial in the network controllability and robustness. Prior art has investigated single, non-interacting complex networks where core structure plays an important role in ensuring the network robustness. In contrast, real networks are usually composed of multiple interdependent layers. Under this circumstance, the network robustness is influenced by not only the intra-layer connections, which represents the structural attributes such as node degree within the same layer, but also the inter-layer dependencies where interdependent nodes across different layers can be preserved or removed in company. In this paper, we take a first look at core percolation in multi-layer networks. For investigation, we start from the double-layer networks and propose an extended algorithm, called Correlated Greedy Leaf Removal (CGLR) procedure, that aims to preserve core nodes by recursively switching among layers in removing leaves in one layer and disenabling their interdependent nodes in other layers. Along with empirical observations, we show that intra-layer connections are manifested to be dominating in determining the existence of core nodes. But more notably, the presence of core structure with strong inter-layer dependencies always exhibits a first order phase transition at the critical point while it undergoes a continuous phase transition in the single-layer undirected networks. These findings are also extendable to networks with more layers, and is of significance in better construction and control of real-life networks.
收起
摘要 :
The core/periphery model is increasingly being used to analyze interbank networks, as it is consistent with theoretical models of interbank market structures. We show that existing core/periphery estimators are inaccurate when the...
展开
The core/periphery model is increasingly being used to analyze interbank networks, as it is consistent with theoretical models of interbank market structures. We show that existing core/periphery estimators are inaccurate when the network is either highly connected relative to the true proportion of banks in the core, or relatively sparsely connected. We derive a & lsquo;density & ndash;based & rsquo; estimator that is designed to overcome these inaccuracies, and show that our estimator outperforms the commonly used estimators in simulations. These results have broad applicability to the network analysis literature. We then use our density & ndash;based estimator to analyze the Australian overnight interbank market, focusing on changes that occurred during the 2007 & ndash;08 financial crisis. Crown Copyright (c) 2021 Published by Elsevier B.V. All rights reserved.The core/periphery model is increasingly being used to analyze interbank networks, as it is consistent with theoretical models of interbank market structures. We show that existing core/periphery estimators are inaccurate when the network is either highly connected relative to the true proportion of banks in the core, or relatively sparsely connected. We derive a ?density?based? estimator that is designed to overcome these inaccuracies, and show that our estimator outperforms the commonly used estimators in simulations. These results have broad applicability to the network analysis literature. We then use our density?based estimator to analyze the Australian overnight interbank market, focusing on changes that occurred during the 2007?08 financial crisis.
收起
摘要 :
We examine network problems where agents have to be connected to a source in order to obtain goods, and in which costs on different arcs are a function of the flow of goods. When all cost functions are concave, the resulting game ...
展开
We examine network problems where agents have to be connected to a source in order to obtain goods, and in which costs on different arcs are a function of the flow of goods. When all cost functions are concave, the resulting game might have an empty core. We introduce a set of problems with concave functions, called the ordered quasi-symmetric congestion problems. We show that they generate permutationally concave games, a weakening of the concept of concavity, that ensures non-emptiness of the core.
收起
摘要 :
Background: Hit network-target sets (HNSs), compiled sets of different network nodes of the same type, are available and play a significant role in cancer development but are notoriously more difficult to select than a single targ...
展开
Background: Hit network-target sets (HNSs), compiled sets of different network nodes of the same type, are available and play a significant role in cancer development but are notoriously more difficult to select than a single target. This is due to a combination of challenges attributed to the differential of node interactions, node heterogeneity, and the limitations of node-hit information. Methods: In this study, we constructed a lung adenocarcinoma regulatory network using TCGA data and obtained different HNSs of driver nodes (DNs), core modules (CMs) and core nodes (CNs) through three kinds of methods. Then, the optimized HNS (OHNS) was obtained by integrating CMs, CNs and DNs, and the performance of different HNSs was evaluated according to network structure importance, control capability, and clinical value. Results: We found that the OHNS has two main advantages, the central location of the network and the ability to control the network, and it plays an important role in the disease network through its multifaceted capabilities. Three unique pathways were discovered in the OHNS, which is consistent with previous experiments. Additionally, 13 genes were predicted to play roles in risk prognosis, disease drivers, and cell perturbation effects of lung adenocarcinoma, of which 12 may be candidates for new drugs and biomarkers of lung adenocarcinoma. Conclusion: This study can help us understand and control a network more effectively to determine the development trend of a disease, design effective multitarget drugs, and guide the therapeutic community to optimize appropriate strategies according to different research aims in cancer treatment.
收起
摘要 :
The design concept of AKARI V.2.0 states that packets of each service (application) are transferred between overlay routers, managed by service providers, and routing nodes in the network of the communication carrier. The carrier ...
展开
The design concept of AKARI V.2.0 states that packets of each service (application) are transferred between overlay routers, managed by service providers, and routing nodes in the network of the communication carrier. The carrier has no means of detecting these packets, so it has to accept a number of limitations including, (1) unable to identify the use status of the network, such as the number of packets transferred, for each service, (2) unable to identify and remove non-permitted packets, (3) unable to restrict the flow of packets into the network (i.e. routing nodes) when communication troubles happened. The author thinks that the AKARI V.2.0 network can never be used for business, since these limitations lead to poor reliability and security. The installation of a gate device, managed by the carrier, between the overlay router and the routing node, can ease management concerns, and solve these problems. The examples of P2P / cloud computing service network and ALM broadcast service networks are shown. Network functions that can set and free temporarily VPN tunnels in the network are described, which are very necessary to support telephony with its massive number of terminals. The method described to improve the AKARI overlay network is also applicable to an IP core network as a substitute for the AKARI core network.
收起
摘要 :
The design concept of AKARI V.2.0 states that packets of each service (application) are transferred between overlay routers, managed by service providers, and routing nodes in the network of the communication carrier. The carrier ...
展开
The design concept of AKARI V.2.0 states that packets of each service (application) are transferred between overlay routers, managed by service providers, and routing nodes in the network of the communication carrier. The carrier has no means of detecting these packets, so it has to accept a number of limitations including, (1) unable to identify the use status of the network, such as the number of packets transferred, for each service, (2) unable to identify and remove non-permitted packets, (3) unable to restrict the flow of packets into the network (i.e. routing nodes) when communication troubles happened. The author thinks that the AKARI V.2.0 network can never be used for business, since these limitations lead to poor reliability and security. The installation of a gate device, managed by the carrier, between the overlay router and the routing node, can ease management concerns, and solve these problems. The examples of P2P/cloud computing service network and ALM broadcast service networks are shown. Network functions that can set and free temporarily VPN tunnels in the network are described, which are very necessary to support telephony with its massive number of terminals. The method described to improve the AKARI overlay network is also applicable to an IP core network as a substitute for the AKARI core network.
收起
摘要 :
The Core Optical Networks (CORONET) program addresses the development of architectures, protocols, and network control and management to support the future advanced requirements of both commercial and government networks, with a f...
展开
The Core Optical Networks (CORONET) program addresses the development of architectures, protocols, and network control and management to support the future advanced requirements of both commercial and government networks, with a focus on highly dynamic and highly resilient multi-terabit core networks. CORONET encompasses a global network supporting a combination of IP and wavelength services. Satisfying the aggressive requirements of the program required a comprehensive approach addressing connection setup, restoration, quality of service, network design, and nodal architecture. This paper addresses the major innovations developed in Phase 1 of the program by the team led by Telcordia and AT&T. The ultimate goal is to transfer the technology to commercial and government networks for deployment in the next few years.
收起
原文获取