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Measurement of proton quenching in a LAB-based liquid scintillator
摘要： In this paper, we propose a mathematical model to evaluate the transmission of Tuberculosis with drug-resistant strains and with drug-sensitive strains. Based on the epidemic data from Chinese Center for Disease Control and Prevention, we first estimate the values of parameters in the model. Then the basic reproduction number of TB infection in the mainland China is calculated to be 1.0558. Since the basic reproduction number is greater than 1, Tuberculosis spreads as an endemic in mainland China. Through our investigations, the basic reproduction number associated with drug-sensitive strains is less than 1, but the number of individuals infected by drug-resistant strains will still increase quickly, thus the epidemic is not under control. Moreover, increasing the vaccination coverage rate for newborns is not always beneficial for controlling TB prevalence in China. Whether vaccination effect is positive or negative depends on the relapse rate from the recovered state to the infected state. In summary, improving sanitation conditions, introducing efficient measures to detect the disease, and keeping the public informed about how to lower the chance of being infected and the current epidemic situation are essential in slowing down or eliminating Tuberculosis transmission.
关键词： Tuberculosis Transmission,Drug-Sensitive Strain,The Basic Reproduction Number,Drug-Resistant Strain,Least-Square Method
更新于2025-09-23 15:23:52
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A measurement method for calibrating kinematic parameters of industrial robots with point constraint by a laser displacement sensor
摘要： This paper proposes a novel calibration method for robot kinematic parameters by constraining a command point with only one single laser displacement sensor. Then, a kinematic error model including both the robot parameter errors and the errors between the robot base frame and the measurement frame is established. An identification algorithm comprising the least square method and the Particle Swarm Optimization algorithm is developed. Comparison simulations are carried out with the proposed method, a least square method, and the traditional identified method. Experiments show that the estimated compensation results are significant with the mean reduced from 10.259mm to 0.845 mm. A verification experiment shows the mean of the relative deviations is decreased from1.674 mm to 0.538 mm.
关键词： algorithm,point constraint,least square method,laser displacement sensor,Robotic kinematic calibration,Particle Swarm Optimization (PSO)
更新于2025-09-23 15:19:57
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High Precision Position Measurement Method for Laguerre-Gaussian Beams Using a Quadrant Detector
摘要： In this paper, we propose a new method to improve the position measurement accuracy for Laguerre-Gaussian beams on a quadrant detector (QD). First, the error effects of the detector diameter and the gap size are taken into account, and the position error compensation factor is introduced into the conventional formula. Then, in order to reduce the number of parameters, the concept of effective radius is proposed. Thus, a new analytical expression is obtained with a best fit using the least square method. It is verified by simulation that this approach can reduce the maximum error by 97.4% when the beam radius is 0.95 mm; meanwhile, the root mean square errors under different radii are all less than 0.004 mm. The results of simulation show that the new method could effectively improve the accuracy of the QD measurement for different radii. Therefore, the new method would have a good prospect in the engineering practice of beam position measurements.
关键词： quadrant detector,detection,Laguerre-Gaussian beams,effective radius,position measurement method,least square method
更新于2025-09-10 09:29:36