An auxiliary device for rotating alfalfa in air flow with waste air recycling was designed in this study. The motion characteristics of rotating alfalfa in air flow and the new crafts of herbage drying for drying homogeneity were studied. An aerodynamic model of alfalfa segments was established based on the result of the experiment on alfalfa rotation in air flow. The movement of alfalfa segments was analyzed using kinematic simulation. The movement trail and the behavior of alfalfa rotation in air flow were tested and verified. Experimental results revealed that the effect of alfalfa rotation in air flow depends on the air flow parameters and the mechanism of the new device. The influence of drying air flow velocity, initial velocity, and air flow angle were analyzed using a nonlinear regression orthogonal design and rotating alfalfa in air flow and building mathematical models of rotating alfalfa parameters on experimental criteria to optimize the parameters of alfalfa drying homogeneity. MATLAB was used for single-target optimization and experimental verification. Optimized drying parameters were ascertained (i.e., air flow velocity, 2.82 m/s; initial velocity, 0.05 m/s; air flow angle, 5.0 to 5.5 ) based on the simulation of the alfalfa drying study and experimental result.
In this paper, the security of spatial database access is studied, which discusses security problems about spatial database access and transmission, and presents a solution to guarantee spatial data access security and solve some problems, including identity authentication and security transmission of secret data. We present a solution to avoid the shortcoming of SSL protocol. At the same time, a new concept is introduced in this paper, which is certificate and private key cruising. Finally, we give an application to verify the solution. It is found that our solution is very convenient to users and can make sure the security of spatial database.
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