The effects of packing configurations on the phase transition of straight granular chute flow with two bottlenecks are studied. The granular flow shows a diluteto-dense flow transition when the channel width is varied, accompanied with a peculiar bistable phenomenon. The bistable phenomenon is induced by the initial packing configuration of particles. When the packing is dense, the initial flux is small and will induce a dense flow. When the packing is loose, the initial flux is large and will induce a dilute flow. The fabric network of granular packing is analyzed from a complex network perspective. The degree distribution shows quantitatively different characteristics for the configurations. A two-dimensional(2D) packing clustering coefficient is defined to better quantify the fabric network.
We study an exclusion process with multiple dynamic roadblocks.Each roadblock can move diffusively forward or backward with different rates,as well as unbind from/rebind to a free site.By Monte Carlo simulations,the two moving types are investigated in combination of roadblock number.The case of only diffusive roadblocks shows an asymmetric current-density relation.The case of only long-range jumping roadblocks presents that flux decreases with increasing roadblock number.
In this paper, an optimal resource allocation strategy is proposed to enhance traffic dynamics in complex networks. The network resources are the total node packet-delivering capacity and the total link bandwidth. An analytical method is developed to estimate the overall network capacity by using the concept of efficient betweenness (ratio of algorithmic betweenness and local processing capacity). Three network structures (scale-free, small-world, and random networks) and two typical routing protocols (shortest path protocol and efficient routing protocol) are adopted to demonstrate the performance of the proposed strategy. Our results show that the network capacity is reversely proportional to the average path length for a particular routing protocol and the shortest path protocol can achieve the largest network capacity when the proposed resource allocation strategy is adopted.
In this paper, we study the optimization of network traffic by considering the effects of node buffer ability and capacity. Two node buffer settings are considered. The node capacity is considered to be proportional to its buffer ability. The node effects on network traffic systems are studied with the shortest path protocol and an extension of the optimal routing [Phys. Rev. E 74 046106 (2006)]. In the diagrams of flux-density relationships, it is shown that a nodes buffer ability and capacity have profound effects on the network traffic.
