受网络吞吐量及稳定性等因素影响,无线网络中的移动视频业务体验欠佳。为了提升移动视频用户体验质量(QoE,Quality of Experience),本文提出一种自由视频码率选择算法,不再对所有用户使用统一的低等级初始码率,而根据用户不同的网络状...受网络吞吐量及稳定性等因素影响,无线网络中的移动视频业务体验欠佳。为了提升移动视频用户体验质量(QoE,Quality of Experience),本文提出一种自由视频码率选择算法,不再对所有用户使用统一的低等级初始码率,而根据用户不同的网络状态来确定码率自适应传输的初始视频码率;同时,在视频播放过程中控制码率平稳变化。仿真实验利用Matlab软件,采用"停等"策略模拟LTE网络中的实时视频传输,以QoE评分为性能度量,验证本文方法的有效性。展开更多
This paper considers the convergence rate of an asymmetric Deffuant-Weisbuch model.The model is composed by finite n interacting agents.In this model,agent i’s opinion is updated at each time,by first selecting one r...This paper considers the convergence rate of an asymmetric Deffuant-Weisbuch model.The model is composed by finite n interacting agents.In this model,agent i’s opinion is updated at each time,by first selecting one randomly from n agents,and then combining the selected agent j’s opinion if the distance between j’s opinion and i’s opinion is not larger than the confidence radiusε0.This yields the endogenously changing inter-agent topologies.Based on the previous result that all agents opinions will converge almost surely for any initial states,the authors prove that the expected potential function of the convergence rate is upper bounded by a negative exponential function of time t when opinions reach consensus finally and is upper bounded by a negative power function of time t when opinions converge to several different limits.展开更多
Initial value sensitivity in technology diffusion, an important problem for firms＇ decision making such as the timing and target market chosen for new technology or product entering the market, has long been limited ...Initial value sensitivity in technology diffusion, an important problem for firms＇ decision making such as the timing and target market chosen for new technology or product entering the market, has long been limited by the research methodology and tool. Based on the network extension of Bass model, this paper proposes a stochastic threshold model and uses computer simulation to empirically examine three propositions on initial value sensitivity in technology diffusion process. Our findings suggest that diffusion extent is sensitive to not only the number of initial adopters but also their positions in social network, and the variance of customers＇ initial assessment as well, which can be detailed as follows： （1） the degree of technology diffusion exhibits highly positive relation to initial adopter quantity, in particular, when the quantity of initial adopters is small, diffusion extent is very sensitive; （2） diffusion extent is sensitive to the positions of initial adopters; （3） in addition, the variance of customers＇ initial evaluation displays strong negative relation to the final diffusion degree in that the larger variance, the lower of diffusion extent.展开更多
文摘受网络吞吐量及稳定性等因素影响,无线网络中的移动视频业务体验欠佳。为了提升移动视频用户体验质量(QoE,Quality of Experience),本文提出一种自由视频码率选择算法,不再对所有用户使用统一的低等级初始码率,而根据用户不同的网络状态来确定码率自适应传输的初始视频码率;同时,在视频播放过程中控制码率平稳变化。仿真实验利用Matlab软件,采用"停等"策略模拟LTE网络中的实时视频传输,以QoE评分为性能度量,验证本文方法的有效性。
基金supported by the Young Scholars Development Fund of Southwest Petroleum University(SWPU)under Grant No.201499010050the Scientific Research Starting Project of SWPU under Grant No.2014QHZ032+1 种基金the National Natural Science Foundation of China under Grant No.61203141the National Key Basic Research Program of China(973 Program)under Grant No.2014CB845301/2/3
文摘This paper considers the convergence rate of an asymmetric Deffuant-Weisbuch model.The model is composed by finite n interacting agents.In this model,agent i’s opinion is updated at each time,by first selecting one randomly from n agents,and then combining the selected agent j’s opinion if the distance between j’s opinion and i’s opinion is not larger than the confidence radiusε0.This yields the endogenously changing inter-agent topologies.Based on the previous result that all agents opinions will converge almost surely for any initial states,the authors prove that the expected potential function of the convergence rate is upper bounded by a negative exponential function of time t when opinions reach consensus finally and is upper bounded by a negative power function of time t when opinions converge to several different limits.
文摘Initial value sensitivity in technology diffusion, an important problem for firms＇ decision making such as the timing and target market chosen for new technology or product entering the market, has long been limited by the research methodology and tool. Based on the network extension of Bass model, this paper proposes a stochastic threshold model and uses computer simulation to empirically examine three propositions on initial value sensitivity in technology diffusion process. Our findings suggest that diffusion extent is sensitive to not only the number of initial adopters but also their positions in social network, and the variance of customers＇ initial assessment as well, which can be detailed as follows： （1） the degree of technology diffusion exhibits highly positive relation to initial adopter quantity, in particular, when the quantity of initial adopters is small, diffusion extent is very sensitive; （2） diffusion extent is sensitive to the positions of initial adopters; （3） in addition, the variance of customers＇ initial evaluation displays strong negative relation to the final diffusion degree in that the larger variance, the lower of diffusion extent.
