Extraction of Tooth Cusps based on DBSCAN Density Clustering and Neighborhood Search Algorithm.

A good tooth cusp extraction is helpful in evaluating the effect of cosmetic dental work in virtual tooth surgery. We propose a new tooth cusp extraction, which integrates the DBSCAN (density-based spatial clustering of applications with noise) clustering algorithm with the neighborhood search algorithm to extract tooth cusp from a three-dimensional cloud-point tooth model. This method used the point cloud height and curvature to screen out the dented point set. Then we employ the DBSCAN clustering algorithm to segment different feature regions of the tooth surface and generate the candidate point set. Finally, the candidate point set was accurately located at the tooth apex through the neighborhood search algorithm and the traversal search method of non-maximum suppression. The experimental results show that the proposed method is superior to the traditional watershed algorithm-based methods by calculating the recall rate and accuracy rate, and also has higher extraction speed and extraction precision than manual extraction methods.

Exploring lemology teaching with "internet plus" flipped classroom pedagogy.

BACKGROUND: To investigate the use of flipped classroom pedagogy based on "Internet plus" in teaching viral hepatitis in the lemology course during the COVID-19 epidemic. METHODS: This study included students from the clinical medicine general practitioner class at Nanjing Medical University's Kangda College, with the observation group consisting of 67 students from the 2020-2021 school year and the control group consisting of 70 students from the 2019-2020 school year. The observation group used "Internet plus" flipped classroom pedagogy, while the control group used conventional offline instruction. The theory course and case analysis ability scores from the two groups were compared and analyzed, and questionnaire surveys were administered to the observation group. RESULT: After the flipped classroom, the observation group had significantly higher theoretical test scores (38.62 ± 4.52) and case analysis ability scores (21.08 ± 3.58) than the control group (37.37 ± 2.43) (t = 2.024, P = 0.045) and (19.16 ± 1.15) (t = 4.254, P < 0.001), respectively. The questionnaire survey in the observation group revealed that the "Internet plus" flipped classroom pedagogy approach can help enhance students' enthusiasm to learn, clinical thinking ability, practical application ability, and learning efficiency, with satisfaction rates of 81.7%, 85.0%, 83.3%, and 78.8%, respectively; 89.4% of students expressed hope that whenever physical classes resumed, the offline courses could be combined with this pedagogy approach. CONCLUSION: The use of the "Internet plus" flipped classroom pedagogy technique for teaching viral hepatitis in a lemology course boosted students' theory learning ability as well as their case analysis ability. The majority of students were pleased with this type of instruction and hoped that whenever physical classes resumed, the offline courses may be integrated with the "Internet plus" flipped classroom pedagogical approach.

The Effectiveness of Plaza Dancing on Psychological Well-Being and Ill-Being: A Systematic Review and Meta-Analysis.

Evidence suggests that participation in plaza dancing may affect mental health. This study for the first time quantified the relationships between plaza dancing and psychological well-being and ill-being. We systematically searched PubMed, Web of Science, CNKI, Wanfang, and VIP to identify relevant studies published from the databases since their inception to July 25, 2021. The standardized mean differences (SMDs) of pre-to-post intervention data were calculated in the meta-analysis. Subgroup and meta-regression analyses were performed to test the potential moderating effects of age, outcome classification, measurement instruments, district, publication year, total sample size, and the duration, frequency, and length of the square dance intervention. A total of 25 original articles met all the eligibility criteria and were included in the review, and 17 studies were included in the meta-analysis. The meta-analysis revealed that plaza dancing improved psychological well-being (pooled SMD = 0.76; 95% CI: 0.58, 0.95; I 2 = 86.9%) and reduced psychological ill-being (pooled SMD = -0.84; 95% CI: -1.00, -0.68; I 2 = 64.8%). The study participants' age and district did not seem to affect the effectiveness of the plaza dancing intervention. The duration and frequency of plaza dancing affected the association between square dance and psychological well-being (duration, ß = -0.044; 95% CI: -0.085, -0.004; frequency, ß = 0.122; 95% CI: 0.024, 0.221) and psychological ill-being (duration, ß = -0.029; 95% CI: -0.040, -0.018; frequency, ß = 0.154; 95% CI: 0.030, 0.278). Plaza dancing has a significant positive effect on psychological well-being and psychological ill-being, and the effects are moderated by intervention modality. Generalizing plaza dancing interventions to promote psychological well-being and prevent or treat psychological ill-being is needed. Systematic Review Registration: [www.crd.york.ac.uk/prospero], identifier [CRD42021272016].

The Impact of Process Conditions on Surge Current Capability of 1.2 kV SiC JBS and MPS Diodes.

This paper demonstrated the impact of process conditions on the surge current capability of 1.2 kV SiC junction barrier Schottky diode (JBS) and merged PiN Schottky diode (MPS). The influence of ohmic contact and defect density produced by implantation was studied in the simulation. The device fabricated with high temperature implantation had less defect density in the implant region compared with room temperature implantation, which contributed to higher hole injection in surge current mode and 20% surge capability improvement. In addition, with lower P+ ohmic contact resistance, the device had higher surge capability. When compared to device fabrication with a single Schottky metal layer in the device active area, adding additional P+ ohmic contact on top of the P+ regions in the device active area resulted in the pn junctions sharing a greater portion of surge current, and improved the devices' surge capability by ~10%.