摘要 :
Detecting node failures in mobile wireless networks is very challenging because the network topology can be highly dynamic, the network may not be always connected, and the resources are limited. In this paper, we take a probabili...
展开
Detecting node failures in mobile wireless networks is very challenging because the network topology can be highly dynamic, the network may not be always connected, and the resources are limited. In this paper, we take a probabilistic approach and propose two node failure detection schemes that systematically combine localized monitoring, location estimation and node collaboration. Extensive simulation results in both connected and disconnected networks demonstrate that our schemes achieve high failure detection rates (close to an upper bound) and low false positive rates, and incur low communication overhead. Compared to approaches that use centralized monitoring, our approach has up to 80 percent lower communication overhead, and only slightly lower detection rates and slightly higher false positive rates. In addition, our approach has the advantage that it is applicable to both connected and disconnected networks while centralized monitoring is only applicable to connected networks. Compared to other approaches that use localized monitoring, our approach has similar failure detection rates, up to 57 percent lower communication overhead and much lower false positive rates (e.g., 0.01 versus 0.27 in some settings).
收起
摘要 :
Many complex systems can be represented as networks consisting of distinct types of interactions, which can be categorized as links belonging to different layers. For example, a good description of the full protein-protein interac...
展开
Many complex systems can be represented as networks consisting of distinct types of interactions, which can be categorized as links belonging to different layers. For example, a good description of the full protein-protein interactome requires, for some organisms, up to seven distinct network layers, accounting for different genetic and physical interactions, each containing thousands of protein-protein relationships. A fundamental open question is then how many layers are indeed necessary to accurately represent the structure of a multilayered complex system. Here we introduce a method based on quantum theory to reduce the number of layers to a minimum while maximizing the distinguishability between the multilayer network and the corresponding aggregated graph. We validate our approach on synthetic benchmarks and we show that the number of informative layers in some real multilayer networks of protein-genetic interactions, social, economical and transportation systems can be reduced by up to 75%.
收起
摘要 :
Load-dependent random walks are used to investigate the evolution of load distribution in trans_portation network systems. The walkers hop to a node according to node load of the last time step. The preference of walks leads to a ...
展开
Load-dependent random walks are used to investigate the evolution of load distribution in trans_portation network systems. The walkers hop to a node according to node load of the last time step. The preference of walks leads to a change in the load distribution. It changes from degree-dependent distri_bution in the case of non-preference walks to eigenvector-centrality-dependent distribution. By numerical simulations, it is shown that the network heterogeneity has a influence on the effect of walk preference. In the cascading failure phenomenon, an appropriate degree correlation can guarantee a low risk of cascading failures.
收起
摘要 :
The raw sewage volume potentially discharged form a sewer network to the environment arising from its component failures is proposed as a measure of overall system reliability. This paper presents a simple method for quickly and p...
展开
The raw sewage volume potentially discharged form a sewer network to the environment arising from its component failures is proposed as a measure of overall system reliability. This paper presents a simple method for quickly and properly calculating this volume. The basis for this method is a representation of the sewer network by a combination of Y-like fragments named here as structure-forming elements.
收起
摘要 :
This paper studies the resilience of logistics network against node failures in the context of express industry owing to disruption in the network. By considering the flow capacity between the nodes and the impact of each node's f...
展开
This paper studies the resilience of logistics network against node failures in the context of express industry owing to disruption in the network. By considering the flow capacity between the nodes and the impact of each node's failure, we propose a load redistribution mechanism in the presence of cascading failures which is akin to a criticality-based resilience assessment or stress testing the supply chain. To further investigate the impact of the node/nodes failure, we simulate and propose algorithms for two cascading failure scenarios, illustrating the different adjustment schemes for resilience improving strategies. A sensitivity analysis with managerial insights is also performed to investigate the effect of the adjustment schemes on the criticality of the nodes and the resilience of the express logistics network.
收起
摘要 :
Telecommunications network is vulnerable to large-scale infrastructure failures caused by physical attacks or natural disasters. Academics view this failure as region failure, which is geographically related and highly localized. ...
展开
Telecommunications network is vulnerable to large-scale infrastructure failures caused by physical attacks or natural disasters. Academics view this failure as region failure, which is geographically related and highly localized. Several simplified models have been previously proposed, resulting in an inaccurate characterization of network activity. In this paper, we propose a probability model with full consideration of the actual situation, which gives a more realistic picture of network behavior. In particular, the disaster takes the form of a randomly placed disk in a plane. The research aims to find out disaster locations that can cause significant damage to network performance, i.e., vulnerable areas of the network. The topology of vulnerable areas can be redesigned to improve the network's disaster survivability. Moreover, only a few special cases need to be judged for the sake of achieving the aim despite disasters occur randomly across the plane. Another primary contribution is our attempt to construct a proper network topology by using clusters as units. Finally, numerical experiments conducted on this network topology demonstrate the applicability of the methodology in realistic scenarios. The work in this paper provides guidance for real-world problems and offers a way to figure them.
收起
摘要 :
Cascading failures of loads in isolated networks and coupled networks have been studied in the past few years. In most of the corresponding results, the topologies of the networks are destroyed. Here, we present an interconnected ...
展开
Cascading failures of loads in isolated networks and coupled networks have been studied in the past few years. In most of the corresponding results, the topologies of the networks are destroyed. Here, we present an interconnected network model considering cascading failures based on the dynamic redistribution of flow in the networks. Compared with the results of single scale-free networks, we find that interconnected scale-free networks have higher vulnerability. Additionally, the network heterogeneity plays an important role in the robustness of interconnected networks under intentional attacks. Considering the effects of various coupling preferences, the results show that there are almost no differences. Finally, the application of our model to the Beijing interconnected traffic network, which consists of a subway network and a bus network, shows that the subway network suffers more damage under the attack. Moreover, the interconnected traffic network may be more exposed to damage after initial attacks on the bus network. These discussions are important for the design and optimization of interconnected networks. (C) 2015 Elsevier B.V. All rights reserved.
收起
摘要 :
Cascading failures on interdependent networks have attracted much attention in recent years. In this paper, we study a cascading failure model on interdependent networks with multiple dependency relations and cliques, in which a c...
展开
Cascading failures on interdependent networks have attracted much attention in recent years. In this paper, we study a cascading failure model on interdependent networks with multiple dependency relations and cliques, in which a clique is dependent on multiple cliques in other network and all nodes in the same clique are survive or fail together. Through a percolation theory, we find that the system always undergoes a first order phase transition when the dependency relations are small. The robustness of the system increases with increasing the number of multiple dependency relations between two networks and the size of cliques. The theory can well predict the numerical simulations. (C) 2019 Elsevier B.V. All rights reserved.
收起
摘要 :
PurposeThe purpose of this paper is to examine network failures and the main reasons why network organizations, intentionally developed by a group of actors to pursue specific goals, become unfruitful and fail in their goals and e...
展开
PurposeThe purpose of this paper is to examine network failures and the main reasons why network organizations, intentionally developed by a group of actors to pursue specific goals, become unfruitful and fail in their goals and expectations of creating collective value. The goal of this paper is thus to contribute a better understanding of the reasons network organizations encounter problems in their dynamics that prevent them from reaching the expected outcomes.Design/methodology/approachThe study is firstly based on a literature review finalized to identify the main variables considered as potentially impacting on network failures. Secondly, the paper is based on a survey conducted on 189 strategic networks that highlighted difficulties in achieving their goals. An analysis of the 24 questionnaires returned generated the results discussed. The empirical study concerns strategic networks intentionally created and signed by Italian SMEs according to a specific law designed to promote the development of inter-firm cooperation ("network contracts").FindingsThe results of the research highlight the role of specific key items related to individual, structural, legitimacy, interaction and governance variables in explaining failures in network organizations. According to the data, failure can occur immediately before the network start-up, resulting in a blocked network or in a subsequent developmental stage, resulting in a dormant network. The empirical research demonstrated that the items affecting network failure differ between blocked and dormant networks. The authors explain such differences, considering them according to the expected goals declared by the two different types of networks.Originality/valueThe question of why networks fail is relevant in times of disruption and digitalization when new forms of organization are needed to link businesses and various stakeholders and thereby develop innovative and sustainable ideas for an entrepreneurial future. However, very few studies have examined network failure. The study contributes to this field of research by investigating the dynamics of networks intentionally developed to reach shared goals. The findings can be useful to both companies that decide to start up a strategic network and the policymakers that promote, finance and monitor inter-firm collaboration.
收起
原文获取