MLCOR Model for Suppressing the Cascade of Edge Failures in Complex Network

2021 ◽  
Author(s):  
Dan Cui ◽  
Ai Zhong Shen ◽  
Yingli Zhang
Keyword(s):  
Load Capacity ◽  
Small World ◽  
Network Economy ◽  
Real Network ◽  
Optimal Network ◽  
Network Operation ◽  
Operation Stability ◽  
The Stability ◽  
Planning And Construction ◽  
Shanghai Metro

As a decisive parameter of network robustness and network economy, the capacity of network edges can directly affect the operation stability and the construction cost of the network. This paper proposes a multilevel load–capacity optimal relationship (MLCOR) model that can substantially improve the network economy on the premise of network safety. The model is verified in artificially created networks including free-scale networks, small-world networks, and in the real network structure of the Shanghai Metro network as well. By numerical simulation, it is revealed that under the premise of ensuring the stability of the network from the destruction caused by initial internal or external damage on edge, the MLCOR model can effectively reduce the cost of the entire network compared to the other two linear load–capacity models regardless of what extent of the destruction that the network edges suffer initially. It is also proved that there exists an optimal tunable parameter and the corresponding optimal network cost for any BA and NW network topology, which can provide the reference for setting reasonable capacities for network edges in a real network at the stage of network planning and construction, promoting security and stability of network operation.

scholarly journals Small world and stability analysis of industrial coupling symbiosis network of ecological industrial park of oil and gas resource cities

2021 ◽  
pp. 014459872098361
Author(s):  
Yanqiu Wang ◽  
Zhengxin Sun ◽  
Pengtai Li ◽  
Zhiwei Zhu
Keyword(s):  
System Analysis ◽  
Oil And Gas ◽  
Small World ◽  
Industrial Park ◽  
Sharp Change ◽  
Connected Subgraph ◽  
Network Efficiency ◽  
Complex Network Theory ◽  
The Stability ◽  
Agglomeration Coefficient

This paper analyzes the small cosmopolitan and stability of the industrial coupling symbiotic network of eco-industrial parks of oil and gas resource-based cities. Taking Daqing A Ecological Industrial Park as an example, we constructed the characteristic index system and calculated the topological parameters such as the agglomeration coefficient and the average shortest path length of the industrial coupling symbiotic network. Based on the complex network theory we analyzed the characteristics of the scaled world, constructed the adjacency matrix of material and information transfers between enterprises, drew the network topology diagram. We simulated the system analysis and analyzed the stability of the industrial coupling symbiotic network of the eco-industrial park using the network efficiency and node load and maximum connected subgraph. The analysis results are as follows: the small world degree δ of Daqing A Eco-industrial Park is 0.891, which indicates that the industrial coupled symbiotic network has strong small world characteristics; the average path is 1.268, and the agglomeration coefficient is 0.631. The probability of edge connection between two nodes in a symbiotic network is 63.1%, which has a relatively high degree of aggregation, indicating that energy and material exchanges are frequent among all enterprises in the network, the degree of network aggregation is high, and the dependence between nodes is high; when the tolerance parameter is 0 to 0.3, the network efficiency and the maximum connected subgraphs show a sharp change trend, indicating that the topology of the industrial coupling symbiotic network of the eco-industrial park changes drastically when the network is subjected to deliberate attacks. It is easy to cause the breakage of material flow and energy flow in the industrial park, which leads to the decline of the stability of the industrial coupling symbiotic network of the eco-industrial park.

scholarly journals Improvement on Load-Induced Cascading Failure in Asymmetrical Interdependent Networks: Modeling and Analysis

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Haiyan Han ◽  
Rennong Yang
Keyword(s):  
Load Capacity ◽  
Small World ◽  
Cascading Failure ◽  
Modeling And Analysis ◽  
Interdependent Networks ◽  
Interdependent Network ◽  
Capacity Model ◽  
Weight Structure ◽  
Edge Failure ◽  
Asymmetrical Model

Many real-world systems can be depicted as interdependent networks and they usually show an obvious property of asymmetry. Furthermore, node or edge failure can trigger load redistribution which leads to a cascade of failure in the whole network. In order to deeply investigate the load-induced cascading failure, firstly, an asymmetrical model of interdependent network consisting of a hierarchical weighted network and a WS small-world network is constructed. Secondly, an improved “load-capacity” model is applied for node failure and edge failure, respectively, followed by a series of simulations of cascading failure over networks in both interdependent and isolated statuses. The simulation results prove that the robustness in isolated network changes more promptly than that in the interdependent one. Network robustness is positively related to “capacity,” but negatively related to “load.” The hierarchical weight structure in the subnetwork leads to a “plateau” phenomenon in the progress of cascading failure.

STABILITY OF TWO TYPICAL COMPLEX DYNAMICAL NETWORKS

2008 ◽  
Vol 22 (05) ◽  
pp. 553-560 ◽  
Author(s):  
WU-JIE YUAN ◽  
XIAO-SHU LUO ◽  
PIN-QUN JIANG ◽  
BING-HONG WANG ◽  
JIN-QING FANG
Keyword(s):  
Numerical Simulation ◽  
Dissipative System ◽  
Small World ◽  
Complex Dynamical Networks ◽  
Dynamical Networks ◽  
Scale Free ◽  
Scale Free Networks ◽  
General Complex ◽  
The Stability ◽  
Theoretical Results

When being constructed, complex dynamical networks can lose stability in the sense of Lyapunov (i. s. L.) due to positive feedback. Thus, there is much important worthiness in the theory and applications of complex dynamical networks to study the stability. In this paper, according to dissipative system criteria, we give the stability condition in general complex dynamical networks, especially, in NW small-world and BA scale-free networks. The results of theoretical analysis and numerical simulation show that the stability i. s. L. depends on the maximal connectivity of the network. Finally, we show a numerical example to verify our theoretical results.

A Review of the Ninth International Conference on the Stability of Ships and Ocean Vehicles (STAB 2006)

2008 ◽  
Vol 45 (03) ◽  
pp. 147-156
Author(s):  
Marcelo A. S. Neves ◽  
Vadim Belenky
Keyword(s):  
Rio De Janeiro ◽  
High Speed ◽  
International Conference ◽  
Intact Stability ◽  
Damage Stability ◽  
Operation Stability ◽  
The Stability

The paper gives a brief review of the papers presented at the Ninth International Conference on Stability of Ships and Ocean Vehicles that was held on September 25 to 29, 2006 in Rio de Janeiro, Brazil. The review covers the following stability-related subjects: stability regulations, intact stability, wind and waves, damage stability, stability in operation, stability of high-speed craft, and offshore vehicles.

Stability-Optimized Clearance Configuration of Fluid-Film Bearings

2006 ◽  
Vol 129 (1) ◽  
pp. 106-111 ◽  
Author(s):  
Koichi Matsuda ◽  
Shinya Kijimoto ◽  
Yoichi Kanemitsu
Keyword(s):  
Fourier Series ◽  
Load Capacity ◽  
Fluid Film ◽  
Eccentricity Ratio ◽  
Rotating Speed ◽  
Fluid Film Bearings ◽  
Wide Range ◽  
Jeffcott Rotor ◽  
The Stability ◽  
Frequency Ratios

The whirl instability occurs at higher rotating speeds for a full circular fluid-film journal bearing, and many types of clearance configuration have been proposed to solve this instability problem. A clearance configuration of fluid-film journal bearings is optimized in a sense of enhancing the stability of the full circular bearing at high rotational speeds. A performance index is chosen as the sum of the squared whirl-frequency ratios over a wide range of eccentricity ratios, and a Fourier series is used to represent an arbitrary clearance configuration of fluid-film bearings. An optimization problem is then formulated to find the Fourier coefficients to minimize the index. The designed bearing has a clearance configuration similar to that of an offset two-lobe bearing for smaller length-to-diameter ratios. It is shown that the designed bearing cannot destabilize the Jeffcott rotor at any high rotating speed for a wide range of eccentricity ratio. The load capacity of the designed bearings is nearly in the same magnitude as that of the full circular bearing for smaller length-to-diameter ratios. The whirl-frequency ratios of the designed bearing are very sensitive to truncating higher terms of the Fourier series for some eccentricity ratio. The designed bearings successfully enhance the stability of a full circular bearing and are free from the whirl instability.

scholarly journals Driving Torque Model and Accuracy Test of Multilink High-Speed Punch

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Fuxing Li ◽  
Hao Liu ◽  
Menglei Li ◽  
Jun Guo ◽  
Xinjian Lu ◽  
...  
Keyword(s):  
High Speed ◽  
Calculation Model ◽  
Effective Control ◽  
Inertia Force ◽  
Conservation Of Energy ◽  
Accuracy Test ◽  
Operation Stability ◽  
Strategy Planning ◽  
The Stability ◽  
Driving Torque

Inertia force is an important factor for operation stability and stamping precision of high-speed punch; adjusting drive torque of high-speed punch can realize effective control of inertia force. In this paper, a kind of 600 KN multilink high-speed punch inertia force balancing mechanism was designed. The calculation model of ideal inertia force was proposed based on conservation of energy and numerical analysis method. In addition, the calculation model of ideal driving torque were analyzed, simplified, and corrected by using numerical calculation and simulation methods, which solved the problem of controlling inertia force from the perspective of driving torque and realized the stability strategy planning of high-speed multilink punch press. Finally, the proposed ideal driving torque calculation model was simulated and verified by ADAMAS and bottom-dead-point accuracy test was carried out.

scholarly journals THE QUESTION OF BOOM LIFTING EQUIPMENT OPERATION STABILITY ON A WHEELED CHASSIS

2021 ◽  
pp. 100-108
Author(s):  
В.И. Токарев ◽  
Н.В. Бабоченко
Keyword(s):  
Longitudinal Direction ◽  
Equipment Operation ◽  
Mathematical Expressions ◽  
Maximum Stability ◽  
Operation Stability ◽  
Quality Of Movement ◽  
The Stability ◽  
The Masses ◽  
Constituent Elements ◽  
Lifting Equipment

В статье представлены на рассмотрение характеристики стабильности работы стреловых грузоподъемных средств на колесном шасси в форме математических выражений. Математические выражения представлены в виде не громоздких зависимостей от конкретно заданных параметров. Качество движения зависит от возрастания линейных размеров, масс, моментов инерции, а также скоростей и других механических параметров грузоподъемных средств. Достижение стабильности работы выносных стреловых грузоподъемных средств достигается путем распределения нагрузки между утлегарью (выносной стрелой грузоподъемного средства) и опорными колесами колесного шасси. Считаем, что при существовании ряда концепцией со своими теориями. возможно определение стабильности работы стрелового грузоподъемного средства на колесном шасси. Нами установлено, что возможно обеспечить стабильность работы путем выбора целесообразных значений механических составляющих всех звеньев рабочего механизма для спланировано составленных рабочих ситуаций. В зависимости от возможного размещения грузоподъемного устройства показатели стабильности работы меняются и это подтверждают составленные нами математические выражения, которые приводятся в статье. Установлено, что путем варьирования различными вариантами положений и массой составляющих элементов конструкции грузоподъемного средства, а также графически определяя возможные варианты перемещения груза в зависимости от заданной длины утлегарьи, имеет место выражение, позволяющее определить ряд значений масс, безопасно поднимаемых грузоподъемным средством. Нами получены значения необходимых для графических построений грузовых характеристик грузоподъемного средства, выражающие зависимость между массой груза и вылетом утлегарьи с весом ее элементов. Реакции в шарнирах утлегарьи и усилия в ее составляющих звеньях возможно установить из данных грузовой характеристики. Стремление обеспечить максимальную стабильность работы грузоподъемного средства накладывает ограничения на контроль за несколькими подвижными операциями одновременно, что неблагоприятно сказывается на эффективности рабочего процесса. Установили, что обеспечение стабильности работы в поперечной и продольной плоскостях грузоподъемного средства является необходимым компонентом безопасной эксплуатации. По зависимостям для определения показателя грузового равновесия возможно определение предварительного места установки выносных опор грузоподъемного средства. Как подтверждают полученные результаты, стабильность работы грузоподъемного средства в продольном направлении определяется аналогично стабильности работы в поперечном направлении и для номинальной массы груза при наибольшем вылете утлегарьи и выставленных выносных опорах. В итоге отметим, что показателем грузового равновесия служит отношение удерживающего момента относительно ребра опрокидывания, создаваемого весом грузоподъемного средства на колесном шасси с учетом уменьшающих его дополнительных внешних нагрузок и влияния уклона площадки к опрокидывающему моменту, создаваемому рабочим грузом. The article presents for consideration the characteristics of the stability of the boom lifting equipment on a wheeled chassis in the form of mathematical expressions. Mathematical expressions are presented in the form of not cumbersome dependencies on specified parameters. The quality of movement depends on the increase in linear dimensions, masses, moments of inertia, as well as speeds, and other mechanical parameters of the lifting equipment. Achievement of the stability of the outboard boom lifting device is achieved by distributing the load between the jib boom (outboard boom of the lifting device) and the support wheels of the wheeled chassis. We believe that with the existence of a number of concepts with their theories, it is possible to determine the stability of the boom lifting device on a wheeled chassis. It has been found that it is possible to ensure the stability of work by choosing the appropriate values of the mechanical components of all links of the working mechanism for planned working situations. Depending on the possible placement of the lifting device, the stability indicators are changed, and this is confirmed by the mathematical expressions we compiled, which are given in the article. It has been established that by varying the positions and the mass of the constituent elements of the structure of the lifting device, as well as graphically defining the possible options of the load moving, depending on the given length of the jib boom, an expression takes place that makes it possible to determine a number of values of the masses safely lifted by the lifting device. There have been obtained the values of the cargo characteristics of the lifting device necessary for graphic constructions, expressing the relationship between the weight of the cargo and the overhanging of the jib boom with the weight of its elements. The reactions in the joints of the jig boom and the forces in its constituent links can be established from the data of the load characteristics. The desire to ensure maximum stability in the operation of the lifting device imposes restrictions on the control of several mobile operations at the same time, which adversely affects the efficiency of the work process. It has been established that ensuring the stability of operation in the transverse and longitudinal planes of the lifting device is a necessary component of safe operation. According to the dependencies for determining the indicator of cargo balance, it is possible to determine the preliminary installation site of the outriggers of the lifting device. As the results obtained confirm, the stability of the operation of the lifting device in the longitudinal direction is determined similarly to the stability of the operation in the transverse direction and for the nominal weight of the load with the greatest overhanging of the jib boom and the set outriggers. As a result, we note that the ratio of the holding moment relative to the overturning rib created by the weight of the lifting device on the wheeled chassis, taking into account the additional external loads that reduce it and the influence of the platform slope to the overturning moment created by the working load, serves as an indicator of the cargo balance.

Study on the Stability and Structural Optimization of Self-Elevating Platform Pile Foundation

2012 ◽  
Vol 203 ◽  
pp. 325-328
Author(s):  
Xin Jie Chu
Keyword(s):  
Stress Concentration ◽  
Structural Optimization ◽  
Bearing Capacity ◽  
Pile Foundation ◽  
Reference Value ◽  
The Self ◽  
Foundation Design ◽  
Operation Stability ◽  
Soil Foundation ◽  
The Stability

This paper analyzes the stability and structural optimization of self-elevating platform pile foundation, preliminarily discusses the method of analyzing the bearing capacity of the layer soil foundation, and establishes the numerical computation models for the whole platform, pile, pile shoe, etc. Besides, through these analyses, the pile structure is optimized, and the stress concentration in the joint between pile and pile shoe is reduced. Also, this study is of reference value for the analysis on the self-elevating platform pile foundation design and the platform operation stability.

Study on the performance of gas foil journal bearings with bump-type shim foil

2020 ◽  
pp. 135065012096900
Author(s):  
Hongyang Hu ◽  
Ming Feng ◽  
Tianming Ren
Keyword(s):  
Dynamic Stability ◽  
Load Capacity ◽  
Practical Interest ◽  
Journal Bearings ◽  
Working Environment ◽  
Foil Thickness ◽  
The Novel ◽  
Improvement Potential ◽  
Stiffness Model ◽  
The Stability

The upscaling of turbomachinery using gas foil journal bearings (GFJBs) is limited because of their limited load capacity and dynamic stability. The improvement potential of shim foil inserted under the bump foil of such bearings is investigated in terms of better bearing performance. The arch height difference Δ hb between the shim foil and bump foil can be zero or not to attain the different effect. By considering the local hardening structural stiffness and an Initial installation clearance due to the shim foil, the static and dynamic characteristics of the novel bearing were calculated through the finite difference method (FDM) and perturbation method, respectively. In the analysis, a modified bump stiffness model considering the variable foil thickness was established, and a 2 D thick plate model was adopted for the top foil. The characteristics of novel GFJB with and without preload were compared with the traditional bearing. The results indicate that the load capacity and direct stiffness of the novel GFJB with shim foil can be increased largely, especially when there is a preload (Δ hb≠0). And the improvement is reinforced as the increment of Δ hb. Moreover, the stability threshold speed ( STS) of rotor supported by the novel GFJBs is enhanced by the preload, which means better stability. In addition, an air compressor test has also been conducted to verify the improved supporting performance of novel bearings. Based on this study it is convinced that the addition of shim foil under a GFJB's bump foil can be of practical interest in the quest of enhanced load capacity and dynamic stability. Moreover, the installation of shim foil is not affected by the working environment and could even be retrofited on the existing GFJBs.

Study on a Website Protection Strategy Based on Network Survivability with Effective Web Materials System

2011 ◽  
Vol 63-64 ◽  
pp. 814-817
Author(s):  
Jian Bo Liu
Keyword(s):  
Data Protection ◽  
System Architecture ◽  
Network Survivability ◽  
Protection System ◽  
Stable Operation ◽  
Network Environment ◽  
Protection Strategy ◽  
Network Operation ◽  
The Stability

Through the research on the network survivability, this paper proposes a website protection strategy based on network survivability from the angle of fine management, in which the paper makes the website server to ensure uninterrupted service under attack and improve the stability of network operation. At the same time this paper proposes a framework for website protection from the perspective of data protection and file protection in order to achieve network survivability. Finally, in accordance with the proposed protection system architecture and strategy, this paper builds the network environment and emulation of illegal attacks, the experiment results show that this strategy can protect the stable operation of the website, and the survivability of website can be reflected.

Sign in / Sign up

Export Citation Format

Share Document