ABSTRACT
This research aimed to optimize the camera calibration process by identifying the optimal distance and angle for capturing checkered board images, with a specific focus on understanding the factors that influence the reprojection error (ϵRP). The objective was to improve calibration efficiency by exploring the impacts of distance and orientation factors and the feasibility of independently manipulating these factors. The study employed Zhang's camera calibration method, along with the 2k full-factorial analysis method and the Latin Hypercube Sampling (LHS) method, to identify the optimal calibration parameters. Three calibration methods were devised: calibration with distance factors (D, H, V), orientation factors (R, P, Y), and the combined two influential factors from both sets of factors. The calibration study was carried out with three different stereo cameras. The results indicate that D is the most influential factor, while H and V are nearly equally influential for method A; P and R are the two most influential orientation factors for method B. Compared to Zhang's method alone, on average, methods A, B, and C reduce ϵRP by 25%, 24%, and 34%, respectively. However, method C requires about 10% more calibration images than methods A and B combined. For applications where lower value of ϵRP is required, method C is recommended. This study provides valuable insights into the factors affecting ϵRP in calibration processes. The proposed methods can be used to improve the calibration accuracy for stereo cameras for the applications in object detection and ranging. The findings expand our understanding of camera calibration, particularly the influence of distance and orientation factors, making significant contributions to camera calibration procedures.
ABSTRACT
Objective To explore the role and mechanism of stabilizing microtubules of endothelial cells and pericytes for ameliorating the dysfunction of microvasculature after spinal cord injury(SCI). Methods The endothelial cells and pericytes from rat brain microvascular tissue (microvessel) were separated and subjected to glucose oxygen deprivation (OGD). The cell viability was detected by CCK-8 and the expression of α-tubulin was detected by immunofluorescence and Western blotting. Rats (n = 36) were subjected to dorsal spinal cord transection at T
ABSTRACT
Clinical novitiate is not only a significant part in the training of basic comprehensive ability of clinical medicine students,but also a weak link in current teaching practice link. This research is guided by the educational reform of the"5+3"talent training mode and it carries out reforms by constructing three-stage novitiate mode, realizing curriculum integration and PBL teaching as well as multi-dimensional performance appraisal etc.It is student-centered and lays emphasis on developing students' autonomous learning ability,basic clinical skills and thinking ability,so as to improve the training quality of the medical professionals and provide a referable novitiate teaching mode for the training of medicine professionals under the new situation.
ABSTRACT
To determine the effect of skin allograft on open neural tube defects (ONTDs), the neural tube was incised open using Hamburger and Hamilton stage 18 or 19 chick embryos for a length of six somites. Embryos were divided into two groups: graft and control (with and without skin allograft). On postoperative day 5, closure of ONTDs was more frequent in the graft group than in the control group (9/15 versus 0/15), and healing was nearly complete. However, typical lipomatous features were not observed. These results suggest that simple mechanical attachment of skin allograft on ONTDs does not lead to lipomatous malformation in chick embryos. On the other hand, our results support a potential role of skin allograft in the management of prenatal spinal ONTDs.
