In this paper, we investigate the relationships between crude oil and refined product prices. We find that nonlinear correlations are stronger in the long-term than in the short-term. Crude oil and product prices are cointegrated and financial crisis in 2007–2008 caused a structural break of...

The optimal layout problem of circle group in a circular container with performance constraints of equilibrium belongs to a class of NP-hard problem. The key obstacle of solving this problem is the lack of an effective global optimization method. We convert the circular packing problem with...

This work presents simulations and experimental measurements of two negative refraction metamaterial samples at microwave frequencies. The two samples are composed of Four-Triangle Split Resonant Rings and Metal Wires (FTSRRs–MWs) with different cell sizes which are found to play an important...

In some real complex systems the structures are difficult to map or changing over time. To explore the evolution of strategies on these complex systems, it is not realistic enough to specify their structures or topological properties in advance. In this paper, we address the evolutionary game on...