Showing papers in "International Journal of Modern Physics C in 2015"

Effects of Al2O3–Cu/water hybrid nanofluid on heat transfer and flow characteristics in turbulent regime

Abstract: In this paper, forced convection of a turbulent flow of pure water, Al2O3/water nanofluid and Al2O3–Cu/water hybrid nanofluid (a new advanced nanofluid composited of Cu and Al2O3 nanoparticles) through a uniform heated circular tube is numerically analyzed. This paper examines the effects of these three fluids as the working fluids, a wide range of Reynolds number (10 000 ≤ Re ≤ 10 0000) and also the volume concentration (0% ≤ ϕ ≤ 2%) on heat transfer and hydrodynamic performance. The finite volume discretization method is employed to solve the set of the governing equations. The results indicate that employing hybrid nanofluid improves the heat transfer rate with respect to pure water and nanofluid, yet it reveals an adverse effect on friction factor and appears severely outweighed by pressure drop penalty. However, the average increase of the average Nusselt number (when compared to pure water) in Al2O3–Cu/water hybrid nanofluid is 32.07% and the amount for the average increase of friction factor would be 13.76%.

Improved efficient static weighted routing strategy on two-layer complex networks

Abstract: Global static routing is one kind of important routing algorithms for complex networks, especially in large communication networks. In this paper, we propose a heuristic global static routing algorithm to mitigate traffic congestion on two-layer complex networks. The proposed routing algorithm extends the relevant static weighted routing algorithm in the literature [Y. Zhou, Y. F. Peng, X. L. Yang and K. P. Long, Phys. Sci. 84, 055802 (2011)]. Our routing path is constructed from a proper assignment of edge weights by considering the static information of both layers and an adjustable parameter α. When this routing algorithm is adopted on BA–BA two-layer networks with an appropriate parameter α, it can achieve the maximum network traffic capacity compared with the shortest path (SP) routing algorithm and the static weighted routing algorithm.

Combination methods for identifying influential nodes in networks

Abstract: Identifying influential nodes is of theoretical significance in many domains. Although lots of methods have been proposed to solve this problem, their evaluations are under single-source attack in scale-free networks. Meanwhile, some researches have speculated that the combinations of some methods may achieve more optimal results. In order to evaluate this speculation and design a universal strategy suitable for different types of networks under the consideration of multi-source attacks, this paper proposes an attribute fusion method with two independent strategies to reveal the correlation of existing ranking methods and indicators. One is based on feature union (FU) and the other is based on feature ranking (FR). Two different propagation models in the fields of recommendation system and network immunization are used to simulate the efficiency of our proposed method. Experimental results show that our method can enlarge information spreading and restrain virus propagation in the application of recommendation system and network immunization in different types of networks under the condition of multi-source attacks.

Simulation study of car accidents at the intersection of two roads in the mixed traffic flow

Abstract: Using cellular automata (CA) Nagel–Schreckenberg (NaSch) model, we numerically study the probability Pac of the occurrence of car accidents at nonsignalized intersection when drivers do not respect the priority rules. We also investigated the impact of mixture lengths and velocities of vehicles on this probability. It is found that in the first case, where vehicles distinguished only by their lengths, the car accidents start to occur above a critical density ρc. Furthermore, the increase of the fraction of long vehicles (FL) delays the occurrence of car accidents (increasing ρc) and increases the risk of collisions when ρ > ρc. In other side, the mixture of maximum velocities (with same length for all vehicles) leads to the appearance of accidents at the intersection even in the free flow regime. Moreover, the increase of the fraction of fast vehicles (Ff) reduces the accident probability (Pac). The influence of roads length is also studied. We found that the decrease of the roads length enhance the risk of collision.

Smoothed Particle Hydrodynamics for water wave propagation in a channel

Abstract: In this paper, Smoothed Particle Hydrodynamics (SPH) is used to simulate the propagation of waves in an intermediate depth water channel. The major advantage of using SPH is that no special treatment of the free surface is required, which is advantageous for simulating highly nonlinear flows with possible wave breaking. The SPH method has an option of different formulations with their own advantages and drawbacks to be implemented. Here, we apply the classical and Arbitrary Lagrange–Euler (ALE) formulation for wave propagation in a water channel. The classical SPH should come with an artificial viscosity which stabilizes the numerical algorithm and increases the accuracy. Here, we will show that the use of classical SPH with an artificial viscosity may cause the waves in the channel to decay. On the other hand, we will show that using the ALE-SPH algorithm with a Riemann solver is more stable, and in addition to producing the pressure fields with much less numerical noise, the waves propagate in the channel without dissipation.

Effect of temperature-dependency of Newtonian and non-Newtonian fluid properties on the dynamics of droplet impinging on hot surfaces

Abstract: In the present work, three-dimensional computational fluid dynamics analysis is employed to study the droplet dynamics of Newtonian and non-Newtonian droplets impinging on a hot surface under various impact conditions. The Navier–Stokes equations for unsteady, incompressible, and viscous fluid flow are solved using a control volume method. The volume-of-fluid (VOF) technique is also used to track the free-surface of the liquid. The effect of viscosity, density and surface tension on droplet dynamics is evaluated considering their dependence of temperature. The results indicate that the temperature dependence of the both Newtonian and non-Newtonian physicochemical liquid properties must be considered to obtain better agreement of the numerical results with experimental data. After ensuring the accuracy of the numerical methodology, the internal behavior of the droplets is examined, which is shown that the receding velocity of the non-Newtonian droplet is slower than the Newtonian one.

Measures of node centrality in mobile social networks

Abstract: Mobile social networks exploit human mobility and consequent device-to-device contact to opportunistically create data paths over time. While links in mobile social networks are time-varied and strongly impacted by human mobility, discovering influential nodes is one of the important issues for efficient information propagation in mobile social networks. Although traditional centrality definitions give metrics to identify the nodes with central positions in static binary networks, they cannot effectively identify the influential nodes for information propagation in mobile social networks. In this paper, we address the problems of discovering the influential nodes in mobile social networks. We first use the temporal evolution graph model which can more accurately capture the topology dynamics of the mobile social network over time. Based on the model, we explore human social relations and mobility patterns to redefine three common centrality metrics: degree centrality, closeness centrality and betweenness centrality. We then employ empirical traces to evaluate the benefits of the proposed centrality metrics, and discuss the predictability of nodes' global centrality ranking by nodes' local centrality ranking. Results demonstrate the efficiency of the proposed centrality metrics.

Numerical study of flow patterns and heat transfer in mini twisted oval tubes

Abstract: Flow patterns and heat transfer inside mini twisted oval tubes (TOTs) heated by constant-temperature walls are numerically investigated. Different configurations of tubes are simulated using water as the working fluid with temperature-dependent thermo-physical properties at Reynolds numbers ranging between 500 and 1100. After validating the numerical method with the published correlations and available experimental results, the performance of TOTs is compared to a smooth circular tube. The overall performance of TOTs is evaluated by investigating the thermal-hydraulic performance and the results are analyzed in terms of the field synergy principle and entropy generation. Enhanced heat transfer performance for TOTs is observed at the expense of a higher pressure drop. Additionally, the secondary flow generated by the tube-wall twist is concluded to play a critical role in the augmentation of convective heat transfer, and consequently, better heat transfer performance. It is also observed that the improvement of synergy between velocity and temperature gradient and lower irreversibility cause heat transfer enhancement for TOTs.

A Cellular Automata occupant evacuation model considering gathering behavior

Abstract: A two-dimensional (2D) Cellular Automata (CA) random model is developed to simulate occupant evacuation considering gathering behavior. The movement process from random distribution to gathering state can be simulated based on the map of the position repulsive force. Evacuations with random distribution and gathering distribution are compared. Visual field means object area coverage considered by the individual in the current cell, representing by the radius of visual field, VR. The simulation results with VR = 1 and 2 have little difference while the simulation with VR = 3 can reasonably represent gathering process. When the occupant density is less than 0.64 people/m2, the time of gathering process increases very fast with the increase of density; when the density is larger than 1.28 people/m2, the time of gathering decreases with the increase of density. When the initial density is less than 1.44 people/m2, the evacuation times with random distribution are always less than those with gathering distribution. When the initial density is larger than 1.44 people/m2, the evacuation times with gathering or random distribution are almost the same. Our model can simulate the gathering and evacuation process with more than two rally points. The number and distribution of rally points can deeply affect the evacuation time.

A hybrid artificial bee colony algorithm for numerical function optimization

Abstract: Artificial Bee Colony (ABC) algorithm is one of the swarm intelligence algorithms; it has been introduced by Karaboga in 2005. It is a meta-heuristic optimization search algorithm inspired from the intelligent foraging behavior of the honey bees in nature. Its unique search process made it as one of the most competitive algorithm with some other search algorithms in the area of optimization, such as Genetic algorithm (GA) and Particle Swarm Optimization (PSO). However, the ABC performance of the local search process and the bee movement or the solution improvement equation still has some weaknesses. The ABC is good in avoiding trapping at the local optimum but it spends its time searching around unpromising random selected solutions. Inspired by the PSO, we propose a Hybrid Particle-movement ABC algorithm called HPABC, which adapts the particle movement process to improve the exploration of the original ABC algorithm. Numerical benchmark functions were used in order to experimentally test the HPABC algorithm. The results illustrate that the HPABC algorithm can outperform the ABC algorithm in most of the experiments (75% better in accuracy and over 3 times faster).

Turbulent fluid-structure interaction of water-entry/exit of a rotating circular cylinder using SPH method

Abstract: This paper studies the two-dimensional (2D) water-entry and exit of a rotating circular cylinder using the Sub-Particle Scale (SPS) turbulence model of a Lagrangian particle-based Smoothed-Particle Hydrodynamics (SPH) method. The full Navier–Stokes (NS) equations along with the continuity have been solved as the governing equations of the problem. The accuracy of the numerical code is verified using the case of water-entry and exit of a nonrotating circular cylinder. The numerical simulations of water-entry and exit of the rotating circular cylinder are performed at Froude numbers of 2, 5, 8, and specific gravities of 0.25, 0.5, 0.75, 1, 1.75, rotating at the dimensionless rates of 0, 0.25, 0.5, 0.75. The effect of governing parameters and vortex shedding behind the cylinder on the trajectory curves, velocity components in the flow field, and the deformation of free surface for both cases have been investigated in detail. It is seen that the rotation has a great effect on the curvature of the trajectory path and velocity components in water-entry and exit cases due to the interaction of imposed lift and drag forces with the inertia force.

Laboratory measurement and interpretation of nonlinear gas flow in shale

Abstract: Gas flow mechanisms in shale are urgent to clarify due to the complicated pore structure and low permeability. Core flow experiments were conducted under reservoir net confining stress with samples from the Longmaxi Shale to investigate the characteristics of nonlinear gas flow. Meanwhile, microstructure analyses and gas adsorption experiments are implemented. Experimental results indicate that non-Darcy flow in shale is remarkable and it has a close relationship with pore pressure. It is found that type of gas has a significant influence on permeability measurement and methane is chosen in this work to study the shale gas flow. Gas slippage effect and minimum threshold pressure gradient weaken with the increasing backpressure. It is demonstrated that gas flow regime would be either slip flow or transition flow with certain pore pressure and permeability. Experimental data computations and microstructure analyses confirm that hydraulic radius of flow tubes in shale are mostly less than 100 nm, indicating that there is no micron scale pore or throat which mainly contributes to flow. The results are significant for the study of gas flow in shale, and are beneficial for laboratory investigation of shale permeability.

Influence analysis of information erupted on social networks based on SIR model

Abstract: In this paper, according to the similarity of chain reaction principle and the characteristics of information propagation on social network, we proposed a new word "information bomb". Based on the complex networks and SIR model, dynamical evolution equations were setup. Then methods used to evaluate the four indexes of bomb power were given, including influence breadth, influence strength, peak time and relaxation time. At last, the power of information was ascertained through these indexes. The process of information propagation is simulated to illustrate the spreading characteristics through the results. Then parameters which impact on the power of information bomb are analyzed and some methods which control the propagation of information are given.

Survivability of public transit network based on network structure entropy

Abstract: In this work, we have collected 195 bus routes and 1433 bus stations of Jinan city as sample date to build up the public transit geospatial network model by applying space L method, until May 2014. Then, by analyzing the topological properties of public transit geospatial network model, which include degree and degree distribution, average shortest path length, clustering coefficient and betweenness, we get the conclusion that public transit network is a typical complex network with scale-free and small-world characteristics. Furthermore, in order to analyze the survivability of public transit network, we define new network structure entropy based on betweenness importance, and prove its correctness by giving that the new network structure entropy has the same statistical characteristics with network efficiency. Finally, the "inflexion zone" is discovered, which can be taken as the momentous indicator to determine the public transit network failure.

Community detection in bipartite networks using weighted symmetric binary matrix factorization

Abstract: In this paper, we propose weighted symmetric binary matrix factorization (wSBMF) framework to detect overlapping communities in bipartite networks, which describes the relationships between two types of nodes. Our method improves performance by recognizing the distinction between two types of missing edges — ones among the nodes in each node type and the others between two node types. Our method can also explicitly assign community membership and distinguish outliers from overlapping nodes, as well as incorporating existing knowledge on the network. We propose a generalized partition density for bipartite networks as a quality function, which identifies the most appropriate number of communities. The experimental results on both synthetic and real-world networks demonstrate the effectiveness of our method.

Attack robustness of cascading load model in interdependent networks

Abstract: Considering the weight of a node and the coupled strength of two interdependent nodes in the different networks, we propose a method to assign the initial load of a node and construct a new cascading load model in the interdependent networks. Assuming that a node in one network will fail if its degree is 0 or its dependent node in the other network is removed from the network or the load on it exceeds its capacity, we study the influences of the assortative link (AL) and the disassortative link (DL) patterns between two networks on the robustness of the interdependent networks against cascading failures. For better evaluating the network robustness, from the local perspective of a node we present a new measure to qualify the network resiliency after targeted attacks. We show that the AL patterns between two networks can improve the robust level of the entire interdependent networks. Moreover, we obtain how to efficiently allocate the initial load and select some nodes to be protected so as to maximize the network robustness against cascading failures. In addition, we find that some nodes with the lower load are more likely to trigger the cascading propagation when the distribution of the load is more even, and also give the reasonable explanation. Our findings can help to design the robust interdependent networks and give the reasonable suggestion to optimize the allocation of the protection resources.

Towards Cost-efficient Sampling Methods

Abstract: The sampling method has been paid much attention in the field of complex network in general and statistical physics in particular. This paper proposes two new sampling methods based on the idea that a small part of vertices with high node degree could possess the most structure information of a complex network. The two proposed sampling methods are efficient in sampling high degree nodes so that they would be useful even if the sampling rate is low, which means cost-efficient. The first new sampling method is developed on the basis of the widely used stratified random sampling (SRS) method and the second one improves the famous snowball sampling (SBS) method. In order to demonstrate the validity and accuracy of two new sampling methods, we compare them with the existing sampling methods in three commonly used simulation networks that are scale-free network, random network, small-world network, and also in two real networks. The experimental results illustrate that the two proposed sampling methods perform much better than the existing sampling methods in terms of achieving the true network structure characteristics reflected by clustering coefficient, Bonacich centrality and average path length, especially when the sampling rate is low.

Structural, electronic and magnetic properties of (N, C)-codoped ZnO nanotube: First principles study

Abstract: We have studied the electronic structure and magnetic properties of Nitrogen and Carbon codoped ZnO (5,0) single-walled zigzag nanotube using first-principle calculations based on the density functional theory. We performed our calculations for N- and C- codoping ZnO nanotube in two different configurations. For the first configuration in which the two impurity atoms (N or C) are on first nearest-neighbor sites in the plane of codoping, our calculation predicts that the N- and C-codoped ZnO nanotubes are antiferromagnetic material with no net magnetization. On the other hand, it is found that for the configuration in which the two impurity atoms are next nearest-neighbors, a spin polarization results in a magnetic moment in the N- and C-codoped ZnO nanotubes.

A novel lattice traffic flow model on a curved road

Abstract: Due to the existence of curved roads in real traffic situation, a novel lattice traffic flow model on a curved road is proposed by taking the effect of friction coefficient and radius into account. The stability condition is obtained by using linear stability theory. The result shows that the traffic flow becomes stable with the decrease of friction coefficient and radius of the curved road. Using nonlinear analysis method, the Korteweg–de Vries (KdV) and modified Korteweg–de Vries (mKdV) equation are derived to describe soliton waves and the kink–antikink waves in the meta-stable region and unstable region, respectively. Numerical simulations are carried out and the results are consistent with the theoretical results.

Experiment and simulation of the bidirectional pedestrian flow model with overtaking and herding behavior

Abstract: In order to effectively depict the characteristics of bidirectional pedestrian flow, a novel pedestrian flow model is proposed based on cellular automata. At first, according to direction gain, velocity gain and herding gain, the calculation formula of target position is defined, and the walking rules by combining overtaking behavior and herding behavior are given in the model. Meanwhile, the actual channel is used for experiments, where the self-organizing effect formed by pedestrian flow is observed. The simulation platform is established to study the key factors influencing pedestrian flow characteristics. The numerical analysis results showed that when the pedestrian density in the channel reached to the critical degree, the overtaking behavior can easily produce jamming. Moreover, pedestrians' rational choice is good for relieving jamming.

Evacuation under limited visibility

Abstract: A multiplicity of situations can trigger off an evacuation of a room under panic conditions. For "normal" (with "normal" meaning absence of obstacles, perfect visibility, etc.) environmental conditions, the "faster is slower" effect dominates the dynamics of this process. It states that as the pedestrians desire to reach the exit increases, the clogging phenomena delays the time to get out of the room. But, environmental conditions are usually far from "normal." In this work, we consider that pedestrians have to find their way out under low visibility conditions. Some of them might switch to a herding-like behavior if they do not remember where the exit was. Others will just trust on their memory. Our investigation handles the herding and memory effects on the evacuation of a single exit room with no obstacles. We also include a section on how signaling devices affect the evacuation process. Unexpectedly, some low visibility situations may enhance the evacuation performance. This can be resumed as a secon...

Analysis of transient flow and starting pressure gradient of power-law fluid in fractal porous media

Abstract: A transient flow model for power-law fluid in fractal porous media is derived by combining transient flow theory with the fractal properties of tortuous capillaries. Pressure changes of transient flow for power-law fluid in fractal porous media are related to pore fractal dimension, tortuosity fractal dimension and the power-law index. Additionally, the starting pressure gradient model of power-law fluid in fractal porous media is established. Good agreement between the predictions of the present model and that of the traditional empirical model is obtained, the sensitive parameters that influence the starting pressure gradient are specified and their effects on the starting pressure gradient are discussed.

An image encryption algorithm based on 3D cellular automata and chaotic maps

Abstract: A novel encryption algorithm to cipher digital images is presented in this work. The digital image is rendering into a three-dimensional (3D) lattice and the protocol consists of two phases: the confusion phase where 24 chaotic Cat maps are applied and the diffusion phase where a 3D cellular automata is evolved. The encryption method is shown to be secure against the most important cryptanalytic attacks.

Cellular automata model simulating traffic car accidents in the on-ramp system

Abstract: In this paper, using Nagel–Schreckenberg model we study the on-ramp system under the expanded open boundary condition. The phase diagram of the two-lane on-ramp system is computed. It is found that the expanded left boundary insertion strategy enhances the flow in the on-ramp lane. Furthermore, we have studied the probability of the occurrence of car accidents. We distinguish two types of car accidents: the accident at the on-ramp site (Prc) and the rear-end accident in the main road (Pac). It is shown that car accidents at the on-ramp site are more likely to occur when traffic is free on road A. However, the rear-end accidents begin to occur above a critical injecting rate αc1. The influence of the on-ramp length (LB) and position (xC0) on the car accidents probabilities is studied. We found that large LB or xC0 causes an important decrease of the probability Prc. However, only large xC0 provokes an increase of the probability Pac. The effect of the stochastic randomization is also computed.

A novel rumor diffusion model considering the effect of truth in online social media

Abstract: In this paper, we propose a model to investigate how truth affects rumor diffusion in online social media. Our model reveals a relation between rumor and truth — namely, when a rumor is diffusing, the truth about the rumor also diffuses with it. Two patterns of the agents used to identify rumor, self-identification and passive learning are taken into account. Combining theoretical proof and simulation analysis, we find that the threshold value of rumor diffusion is negatively correlated to the connectivity between nodes in the network and the probability β of agents knowing truth. Increasing β can reduce the maximum density of the rumor spreaders and slow down the generation speed of new rumor spreaders. On the other hand, we conclude that the best rumor diffusion strategy must balance the probability of forwarding rumor and the probability of agents losing interest in the rumor. High spread rate λ of rumor would lead to a surge in truth dissemination which will greatly limit the diffusion of rumor. Furthermore, in the case of unknown λ, increasing β can effectively reduce the maximum proportion of agents who do not know the truth, but cannot narrow the rumor diffusion range in a certain interval of β.

Kinematical measurement of hydraulic tortuosity of fluid flow in porous media

Abstract: It is hard to experimentally or analytically derive the hydraulic tortuosity (τ) of porous media flow because of their complex microstructures. In this work, we propose a kinematical measurement method for τ by introducing the concept of local tortuosity, which is defined as the ratio of fluid particle velocity to its component along the macro flow. And then, the calculation model of τ is analytically deduced in terms of that τ is the mean value of the local tortuosity. To avoid the impact from the singularity of local tortuosity, the velocity is normalized, and τ is then approximated by the ratio of the mean normalized velocity to the average value of its component along the macro-flow direction. The new estimation method is verified by flow through different types of porous media via the lattice Boltzmann method, and the relationships between permeabilities and tortuosities obtained by different methods are examined. The numerical results show that tortuosity by the novel approach is in good agreement with the existing theory, and the kinematic definition of hydraulic tortuosity is also proven.

Feedback control of digital chaotic systems with application to pseudorandom number generator

Abstract: The dynamical properties will degrade when chaotic systems are implemented in digital computers with finite precisions, and such degradation often has serious negative influence on some digital chaos-based systems. Degradation reduction for a class of digital chaotic systems is investigated in this paper. A varying parameter control method is proposed based on the state feedback control technology at first. Then two chaotic maps are applied to verify its validity. Finally, a novel pseudorandom number generator is constructed, which can pass all the tests of NIST SP800-22 at both level-one and level-two approaches and also most of the tests of TestU01. Moreover, it performs better than some existing pseudorandom number generators. Thus, it has acceptable quality of randomness and can be used for cryptography and other applications.

An algorithm to find critical execution paths of software based on complex network

Abstract: The critical execution paths play an important role in software system in terms of reducing the numbers of test date, detecting the vulnerabilities of software structure and analyzing software reliability. However, there are no efficient methods to discover them so far. Thus in this paper, a complex network-based software algorithm is put forward to find critical execution paths (FCEP) in software execution network. First, by analyzing the number of sources and sinks in FCEP, software execution network is divided into AOE subgraphs, and meanwhile, a Software Execution Network Serialization (SENS) approach is designed to generate execution path set in each AOE subgraph, which not only reduces ring structure's influence on path generation, but also guarantees the nodes' integrity in network. Second, according to a novel path similarity metric, similarity matrix is created to calculate the similarity among sets of path sequences. Third, an efficient method is taken to cluster paths through similarity matrice...

A new car following model from the perspective of visual imaging

Abstract: The paper proposes a car following model from the perspective of visual imaging (VIM), where the visual imaging size of the preceding vehicle on a driver's retina is considered as the stimuli and determines the driving behaviors. NGSIM trajectory data are applied to calibrate and validate the VIM under two scenarios, i.e. following the car and following the truck, whose fitting performance outperforms that of visual angle car following model (VAM). Through linear stability analyses for VIM, it can be drawn that the asymmetry in traffic flow is preserved; the larger vehicle width, vehicle length and vehicle apparent size all benefit enlarging the traffic flow stable region; the traffic flow unstable region when following the car tends to fall in the relatively small distance headway range compared with that when following the truck. After that, numerical experiments demonstrate that the visual imaging information applied in VIM is more contributive to the traffic flow stability than the visual angle information in VAM when following the truck in the relatively large distance headway or involving the driver's perception threshold, i.e. Weber ratio; introducing Weber ratio would break the originally stable traffic flow or deteriorate the traffic fluctuation, which however can be alleviated by increasing drivers' sensitivity, e.g., decreasing Weber ratio. Finally, VIM is verified to be able to satisfy the consistency criteria well from the theoretical aspect.

Quality effort decision in service supply chain with quality preference based on quantum game

Abstract: Service quality preference behaviors of both members are considered in service supply chain (SSC) including a service integrator and a service provider with stochastic demand. Through analysis of service quality cost and revenue, the utility functions are established on service quality effort degree and service quality preference level in integrated and decentralized SSC. Nash equilibrium and quantum game are used to optimize the models. By comparing the different solutions, the optimal strategies are obtained in SSC with quality preference. Then some numerical examples are studied and the changing trend of service quality effort is further analyzed by the influence of the entanglement operator and quality preferences.