Simulation of Magnetorheological Fluids Based on Lattice Boltzmann Method with Double Meshes

In order to study the rheological characteristics of magnetorheological fluids, a novel approach based on the two-component Lattice Boltzmann method with double meshes was proposed, and the micro-scale structures of magnetorheological fluids in different strength magnetic fields were simulated. The framework composed of three steps for the simulation of magnetorheological fluids was addressed, and the double meshes method was elaborated. Moreover, the various internal and external forces acting on the magnetic particles were analyzed and calculated. The two-component Lattice Boltzmann model was set up, and the flowchart for the simulation of magnetorheological fluids based on the two-component Lattice Boltzmann method with double meshes was designed. Finally, a physics experiment was carried out, and the simulation examples were provided. The comparison results indicated that the proposed approach was feasible, efficient, and outperforming others

Channel Estimation and Uplink Achievable Rates in One-Bit Massive MIMO Systems

This paper considers channel estimation and achievable rates for the uplink of a massive multiple-input multiple-output (MIMO) system where the base station is equipped with one-bit analog-to-digital converters (ADCs). By rewriting the nonlinear one-bit quantization using a linear expression, we first derive a simple and insightful expression for the linear minimum mean-square-error (LMMSE) channel estimator. Then employing this channel estimator, we derive a closed-form expression for the lower bound of the achievable rate for the maximum ratio combiner (MRC) receiver. Numerical results are presented to verify our analysis and show that our proposed LMMSE channel estimator outperforms the near maximum likelihood (nML) estimator proposed previously.Comment: 5 pages, 2 figures, the Ninth IEEE Sensor Array and Multichannel Signal Processing Worksho

Nutrition Diet of Grazing Sheep and Forage Supply on Natural Grassland

Forages are a major asset of any livestock operation and the foundation of most rations in a forage-based livestock system. The available nutrients in a forage influence individual animal production (e.g. gain per animal), while the amount of forage produced affects production per hectare. The relationship between voluntary food intake and animal productivity is well recognized. Many studies related to the regulation of food consumption by sheep and cattle have been reported (Provenza 1996). Willoughby (1958) dis-cussed a number of factors which might influence the herbage intake of grazing animals. By contrast, less attention has been given to the nutritional supply which influences the intake of herbage by grazing animals. It is necessary to know about animal daily nutrient requirements for production and forage supply in order to evaluate grazing capacity

Analysis of an Upper Bound on the Effects of Large Scale Attenuation on Uplink Transmission Performance for Massive MIMO Systems

Massive multiple-input multiple-output (MIMO) is a potential candidate key technology for the 5G of wireless communication systems. In research to date, different power loss and shadowing effects on different antenna elements across the large arrays have been neglected. In this paper, based on an idealized propagation model, a new large scale attenuation (LSA) model is proposed, by which the large scale losses (path loss and shadowing effect) over the antenna array can be considered when establishing a massive MIMO channel model. By using this model, the spectral efficiency (in terms of bits/s/Hz sum-rate) of the maximum ratio combining (MRC) detector is derived for the uplink. The spectral efficiency performance of the zero forcing (ZF) detector also can be derived in the same manner. It can be found that the sumrate performance (MRC and ZF) of our proposed channel model (assuming independent shadowing on all elements of the array) exceeds that of the conventional model (where the LSA effect is not included). Based upon our theoretical and simulation analysis, we have found that the spectral efficiency gap is mainly from the mean value of different shadowing effects across different elements, and the different path losses experienced by different antenna elements provide negligible contribution. This LSA model and the derived performance results could be beneficial and informative for the research, design and evaluation of the next generation of wireless communication system employing a massive MIMO configuration