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Guangping Li,Steven David Blostein,Guangchi Zhang,Jiuchao Feng 한국전자통신연구원 2012 ETRI Journal Vol.34 No.2
This letter analyzes the performance of a two-hop MIMO multiuser relay network with a fixed gain amplify-and-forward protocol and antenna selection at the transmitter and receiver. A new expression for the cumulative distribution function of the highest instantaneous end-to-end signal-to-noise ratio is derived. Based on the above result, closed-form expressions for outage probability and bit error rate are presented. Also, the diversity order of the system is determined. Finally, computer simulations are compared to the analytical results, and insights and observations are provided.
Aerodynamic drag reduction based on static traveling wave structure
Xingjun Hu,Zewei Wang,Jiuchao Li,Guo Yu,Jingyu Wang,Wei Lan,Jinglong Zhang,Pengzhan Ma 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5
To explore the influence of the traveling wave parameters on the aerodynamic characteristics of Ahmed models, the geometric model of the traveling wave wall is used as the study object, and the influence of the traveling wave geometric parameters on aerodynamic drag is studied by numerical simulation. A cosine-type traveling wave digital model is established on the basis of Ahmed’s original model. Results show that the static traveling wave structure can play a good role in reducing drag under some driving conditions. The traveling wave’s drag reduction characteristics are affected by the layout position, depth, wavelength, and other related parameters and more affected by driving speed. Finally, a group of working conditions with good drag reduction effects is selected, and the principle of drag reduction by using static traveling wave structure is explained qualitatively and quantitatively through velocity field, shear stress, and pressure field.