Transfer stability of urban subway network with passenger flow: Evidence in Beijing

2018 ◽  
Vol 32 (14) ◽  
pp. 1850174 ◽  
Author(s):  
Hui Zhang ◽  
Baiying Shi ◽  
Xiaohua Yu ◽  
Zhenhua Mou ◽  
Meiling Li ◽  
...  
Keyword(s):  
Network Structure ◽  
Network Performance ◽  
Crucial Issue ◽  
Transfer Number ◽  
Passenger Flow ◽  
Network Evaluation ◽  
The Stability ◽  
Significant Increment

Stability of urban subway systems is a crucial issue in daily operation. This paper proposes a node failing process to test the stability of subway network by structure-based and flow-based node evaluation indicators. Furthermore, three network evaluation indicators are used to measure the network performance. The average transfer number of times (ATT) that is strongly associated with network structure and passenger flow will be discussed specifically. The results show that removing nodes with large inbound passenger flow cannot effectively damage the subway network structure, but it can result in significant increment of the ATT in the whole network. Another finding is that the ATT is smaller in peak hours compared with off-peak hours.

scholarly journals Mutualistic strategies minimize coextinction in plant–disperser networks

2017 ◽  
Vol 284 (1854) ◽  
pp. 20162302 ◽  
Author(s):  
Evan C. Fricke ◽  
Joshua J. Tewksbury ◽  
Elizabeth M. Wandrag ◽  
Haldre S. Rogers
Keyword(s):  
Network Structure ◽  
Field Experiments ◽  
Empirical Relationship ◽  
Network Models ◽  
Mutualistic Interactions ◽  
Simulated Network ◽  
Direct And Indirect Impacts ◽  
Indirect Impacts ◽  
The Stability ◽  
Seed Dispersal Mutualism

The global decline of mutualists such as pollinators and seed dispersers may cause negative direct and indirect impacts on biodiversity. Mutualistic network models used to understand the stability of mutualistic systems indicate that species with low partner diversity are most vulnerable to coextinction following mutualism disruption. However, existing models have not considered how species vary in their dependence on mutualistic interactions for reproduction or survival, overlooking the potential influence of this variation on species' coextinction vulnerability and on network stability. Using global databases and field experiments focused on the seed dispersal mutualism, we found that plants and animals that depend heavily on mutualistic interactions have higher partner diversity. Under simulated network disruption, this empirical relationship strongly reduced coextinction because the species most likely to lose mutualists depend least on their mutualists. The pattern also reduced the importance of network structure for stability; nested network structure had little effect on coextinction after simulations incorporated the empirically derived relationship between partner diversity and mutualistic dependence. Our results highlight a previously unknown source of stability in mutualistic networks and suggest that differences among species in their mutualistic strategy, rather than network structure, primarily accounts for stability in mutualistic communities.

scholarly journals An Efficient Leader Node Selection for Movable Nodes in WSN using PSO Technique

2019 ◽  
Vol 8 (6) ◽  
pp. 5072-5078
Keyword(s):  
Energy Efficient ◽  
Network Performance ◽  
Clustering Algorithm ◽  
Group Formation ◽  
Residual Energy ◽  
Sensor Nodes ◽  
Delivery Ratio ◽  
Efficient Prediction ◽  
The Stability ◽  
Effective Group

Wireless Sensor Networks (WSN) is a group of sensor devices, which are used to sense the surroundings. The network performance is still an issue in the WSN and an efficient protocol is introduced such as LEACH. To improve the stability, LEACH with fuzzy descriptors is used in preceding research. However the existing has drawback with effective group formation in heterogeneous WSN and also it is not achieved the Super Leader Node (SLH). To overcome the above mentioned issues, the proposed system enhances the approach which is used for increasing the energy consumption, packet delivery ratio, and bandwidth and network lifetime. The proposed paper contains three phases such as grouping formation, Leader Node (LN) selection, SLN selection with three main objectives:(i) to acquire Energy-Efficient Prediction Clustering Algorithm (EEPCA) in heterogeneous WSN for grouping formation (ii)To design Low Energy Adaptive Clustering Hierarchy- Expected Residual Energy (LEACH-ERE) protocol for LN selection.(iii)To optimize the SCH selection by Particle Swarm Optimization (PSO) based fuzzy approach. The clustering formation is done by Energy-Efficient Prediction Clustering Algorithm (EEPCA) in heterogeneous WSN. It is used to calculate the sensor nodes which have shortest distance between each node. The LEACH-ERE protocol was proposed to form a Leader Node (LN) and all the nodes has to communicate with sink through LN only. New SLN is elected based on distance from the sink and battery power of the node.

scholarly journals Stability criterion and its calculation for sail-assisted ship

2015 ◽  
Vol 7 (1) ◽  
pp. 1-9
Author(s):  
Yihuai Hu ◽  
Juanjuan Tang ◽  
Shuye Xue ◽  
Shewen Liu
Keyword(s):  
Computational Methods ◽  
Stability Criterion ◽  
Crucial Issue ◽  
Specific Criterion ◽  
The Stability

ABSTRACTStability criterion and its calculation are the crucial issue in the application of sail-assisted ship. How- ever, there is at present no specific criterion and computational methods for the stability of sail-assisted ship. Based on the stability

An Efficient Numerical Simulation for Solving Dynamical Systems With Uncertainty

2017 ◽  
Vol 12 (5) ◽  
Author(s):  
Ali Ahmadian ◽  
Soheil Salahshour ◽  
Chee Seng Chan ◽  
Dumitur Baleanu
Keyword(s):  
Dynamical Systems ◽  
Stability And Convergence ◽  
Uncertain Parameters ◽  
Crucial Issue ◽  
Computational Costs ◽  
First Order ◽  
Wide Range ◽  
Linear And Nonlinear ◽  
The Stability ◽  
Fuzzy Dynamical Systems

In a wide range of real-world physical and dynamical systems, precise defining of the uncertain parameters in their mathematical models is a crucial issue. It is well known that the usage of fuzzy differential equations (FDEs) is a way to exhibit these possibilistic uncertainties. In this research, a fast and accurate type of Runge–Kutta (RK) methods is generalized that are for solving first-order fuzzy dynamical systems. An interesting feature of the structure of this technique is that the data from previous steps are exploited that reduce substantially the computational costs. The major novelty of this research is that we provide the conditions of the stability and convergence of the method in the fuzzy area, which significantly completes the previous findings in the literature. The experimental results demonstrate the robustness of our technique by solving linear and nonlinear uncertain dynamical systems.

scholarly journals A novel optical network model for network burden release and congestion reduction based on passive optical network

2018 ◽  
Vol 14 (10) ◽  
pp. 155014771880765
Author(s):  
He Li ◽  
Hongxi Yin ◽  
Shanshan Lin
Keyword(s):  
Data Storage ◽  
Network Structure ◽  
Network Performance ◽  
Optical Network ◽  
Clustering Coefficient ◽  
Passive Optical Network ◽  
Metropolitan Area Networks ◽  
Performance Simulation ◽  
Storage Devices ◽  
Optical Line

In this article, a new optical network structure coping with network congestion is proposed, which is based on passive optical network, and adopts data storage devices coupled with optical line terminal to release network burden. It is shown by our network performance simulation that this network has many merits such as free-scale, fewer connections, larger clustering coefficient, and smaller average shortest path length in comparison to the passive optical network. The novel network structure can replace the far-end service connections with the near-end ones, reduce congestions in an optical network, and, furthermore, relieve traffic burden in optical backbone and metropolitan area networks.

Governing metal–organic frameworks towards high stability

2016 ◽  
Vol 52 (55) ◽  
pp. 8501-8513 ◽  
Author(s):  
Na Li ◽  
Jian Xu ◽  
Rui Feng ◽  
Tong-Liang Hu ◽  
Xian-He Bu
Keyword(s):  
Chemical Composition ◽  
High Stability ◽  
Metal Organic Frameworks ◽  
Crucial Issue ◽  
Practical Applications ◽  
Metal Organic ◽  
The Stability

Stability of MOFs is a crucial issue for their practical applications, which might be improved by varying their chemical composition and/or structurally tuning them. Several strategies for enhancing the stability of MOFs were provided.

scholarly journals Genetics-based interactions of foundation species affect community diversity, stability and network structure

2017 ◽  
Vol 284 (1854) ◽  
pp. 20162703 ◽  
Author(s):  
Arthur R. Keith ◽  
Joseph K. Bailey ◽  
Matthew K. Lau ◽  
Thomas G. Whitham
Keyword(s):  
Network Structure ◽  
Experimental Manipulation ◽  
Species Interaction ◽  
Foundation Species ◽  
Interaction Networks ◽  
Community Diversity ◽  
Arthropod Community ◽  
Pemphigus Betae ◽  
In The Wild ◽  
The Stability

We examined the hypothesis that genetics-based interactions between strongly interacting foundation species, the tree Populus angustifolia and the aphid Pemphigus betae , affect arthropod community diversity, stability and species interaction networks of which little is known. In a 2-year experimental manipulation of the tree and its aphid herbivore four major findings emerged: (i) the interactions of these two species determined the composition of an arthropod community of 139 species; (ii) both tree genotype and aphid presence significantly predicted community diversity; (iii) the presence of aphids on genetically susceptible trees increased the stability of arthropod communities across years; and (iv) the experimental removal of aphids affected community network structure (network degree, modularity and tree genotype contribution to modularity). These findings demonstrate that the interactions of foundation species are genetically based, which in turn significantly contributes to community diversity, stability and species interaction networks. These experiments provide an important step in understanding the evolution of Darwin's ‘entangled bank’, a metaphor that characterizes the complexity and interconnectedness of communities in the wild.

Influence of Accelerator Residues on Age Resistance of Vulcanizates

1960 ◽  
Vol 33 (2) ◽  
pp. 490-501
Author(s):  
Z. T. Ossefort
Keyword(s):  
Zinc Oxide ◽  
Natural Rubber ◽  
Network Structure ◽  
Dual Process ◽  
Curing Process ◽  
Active Inhibitor ◽  
The Stability ◽  
Prime Function ◽  
Better Than

Abstract It has been shown that the age resistance of elastomeric vulcanizates is influenced to a very marked degree by residues formed in situ in the vulcanizate during the curing process. By a dual process of removal of these residues and incorporation of selected ingredients subsequent to vulcanization, it has been shown that age resistance (as measured by accelerated oven-aging tests at 212° F) in rubbers cured by sulfur and/or sulfur bearing accelerators, is a prime function of these residues and nearly independent of the stability of the network structure. An extremely active inhibitor is formed in situ during vulcanization of SBR and natural rubber using thiuram accelerators. This inhibitor can be used to “reinhibit” acetone-extracted accelerator-cured rubber. When added to sulfur/accelerator, peroxide, or radiation-cured vulcanizates, it improves their age resistance, but only in the case of the sulfur/accelerator cured rubber is this improvement better than with conventional inhibitors. This leads to the conclusion that the efficiency with which an inhibitor protects a vulcanizate varies widely, and conversely it appears that certain types of network structures are more readily protected or that certain inhibitors can function more efficiently in the protection of certain structures than others. In the case of natural rubber cured with TMTD (zinc oxide present), the bulk of the accelerator residue is ZnDMDC, and this residue has been shown to function as a very efficient antioxidant when incorporated into acetone-extracted, accelerator-cured vulcanizate. It is no more effective than conventional inhibitors, however, when incorporated into an acetone-extracted, sulfur/accelerator-cured vulcanizate. Finally, it has been shown that acetone extraction of the various vulcanizates may lead to improvement or worsening of their age resistance, depending upon the nature of the residues resulting from the curing process.

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