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Since the COVID-19 outbreak, high numbers of patients with respiratory symptoms flock to fever clinic, cause overcrowding. Due to relatively densely populated space and the existing ventilation strategy, lead to space environment bearing capacity lose efficacy. The patients in waiting space are faced a high risk of cross infection. Thus, it must be strictly controlling the personnel density and fresh air dilution level, prevent SARS-COV-2 transmission though aerosols. This study takes the fever clinic of 3A Grade Hospital case, based on the monitoring results of CO2 concentration and the transport of exhaled pathogenic aerosols, predict the waiting patient’s cross infection risk in crowded space. Computational fluid dynamics simulations and agent social force behaviour model were used. When the number of fever clinic reaches the upper limit of theoretical capacity, under the three ventilation types, average exposure risk in different areas of waiting space were studied. Results show that when the infector is located at the front of the waiting corridor (upwind direction of natural ventilation), when there is only natural ventilation, the difference of average intake fraction in the three areas of waiting space is small, that is, the correlation between distance and exposure is small. Our results also show that when ceiling air conditioner ventilation and natural ventilation are coupled, the dilution effect is significantly lower than that of natural ventilation in the front and rear area, and higher than only run mechanical ventilation.

5-axis flank milling is applied extensively in aerospace, die-molds, and automotive industries because of high efficient material removal rate. Commercial CAM software can only simulate the tool path and collision at present, but cannot handle with cutting force during cutting process due to the variable geometrical cutter workpiece engagement (CWE) region of 5-axis milling. This paper presents a novel solid analytical model for extracting the CWE maps. The CWE is obtained analytically by performing Boolean operations between the cutter and in-process-workpiece (IPW) at any given cutter location (CL) point, instead of using the cutter and the removal volume. The proposed process simulation method could identify the CWE efficiently and precisely for general cutting tools. Finally, the CWE boundaries are mapped from a 3D space into a 2D plane defined by the immersion angle and the axial depth of a given cutter. The proposed solution can be easily integrated into the CAM software for predicting milling force and optimizing parameters in 5-axis milling.

The total viable count (TVC) in bacon overweight can cause serious damage to human health. In order to find a rapid and nondestructive method of TVC, hyper spectral imaging technique was applied to quantitatively analysis of TVC on bacon. Comprehensively comparing the pretreatment method of multiple scattering, derivative method and so on finally the multiple scattering for pretreatment was used. And the interval optimization method of least squares model was set up to predict, and get a good prediction results. The correlation coefficient of the calibration and predictions respectively was 0.808 and 0.808, interactive authentication root mean square error was 0.115 and 0.198 respectively. Therefore, hyper spectral imaging technique combining iPLS can be used for the rapid detection of TVC on bacon.