Level-crossing rate and average duration of fades for mobile radio channel with hyperbolically distributed scatterers

In this paper we study the geometrical and time-variant wireless vector channel model with hyperbolically distributed scatterers for a macrocell mobile environment. In this study we investigate the level-crossing rate (LCR), the average duration of fades (ADF), the probability density function (PDF), the cumulative distribution function (CDF) and the autocorrelation functions (ACF) of this recently-proposed model. The simulated results are verified against the analytical Clarke's channel model. In this paper we study the geometrical and time-variant wireless vector channel model with hyperbolically distributed scatterers for a macrocell mobile environment. In this study we investigate the level-crossing rate (LCR), the average duration of fades (ADF), the probability density function (PDF), the cumulative distribution function (CDF) and the autocorrelation functions (ACF) of this recently-proposed model. The simulated results are verified against the analytical Clarke's channel model

The reinforcing influence of recommendations on global diversification

Recommender systems are promising ways to filter the overabundant information in modern society. Their algorithms help individuals to explore decent items, but it is unclear how they allocate popularity among items. In this paper, we simulate successive recommendations and measure their influence on the dispersion of item popularity by Gini coefficient. Our result indicates that local diffusion and collaborative filtering reinforce the popularity of hot items, widening the popularity dispersion. On the other hand, the heat conduction algorithm increases the popularity of the niche items and generates smaller dispersion of item popularity. Simulations are compared to mean-field predictions. Our results suggest that recommender systems have reinforcing influence on global diversification.Comment: 6 pages, 6 figure

An efficient mobile Rayleigh fading channel simulator: A comparison with Clarke's Model

This paper presents a computer model for Rayleigh fading channels. The simulated Rayleigh fading channel model is based on Smith's method and shows ease of implementation and greater mathematical tractability. We then investigate the level-crossing rate (LCR), the average duration of fades (ADF), the probability density function (PDF), the cumulative distribution function (CDF) and the autocorrelation functions (ACF) of this proposed model. The simulated results are verified against the analytical Clarke's channel model

Simulating the dynamic behavior of droplet in a grooved channel by dissipative particle dynamics

In this paper, an improved dissipative particle dynamics (DPD) method was applied to simulate droplet motion in a grooved microchannel. Firstly the static contact angle between the droplet and the solid wall was simulated with the improved potential function, and "static contact angle~awf/af " curve was obtained by Polynomial Fit of the 2nd order. Then the influences of wall wettability, flow field force on the flow pattern of droplet were investigated in a grooved microchannel. The results show that wall wettability and flow field force have large effects on the flow pattern of the droplet