面膜类化妆品微生物检验方法适用性考察

对面膜类化妆品的微生物检验方法适用性进行考察,结果表明,当采用培养基稀释法0.5mL/皿测定菌落总数及霉菌和酵母菌总数,采用现行的《化妆品安全技术规范》 2015年版方法检查控制菌时,各菌回收率均能达到要求。建议在检验前针对不同化妆品种类优化微生物计数和控制菌检查方法,提高样品中潜在微生物的阳性检出率。     

基于深度学习的白菜田杂草分割

田间除草在农业生产中具有重要意义,传统杂草识别方式具有效率低或者局限性大的缺点。为此提出将Mask R-CNN算法应用到自然光照下杂草幼苗和白菜幼苗的图像识别。实验选取常见杂草幼苗和白菜幼苗图像作为训练集训练网络,经测试集测试得到81%的合格率。与传统阈值分割算法对比,Mask R-CNN在不同环境下都能精确地识别出杂草幼苗,解决了传统图像算法在复杂光照和叶片遮挡环境下图像难以分割的问题,并且避免了分类器设置工作。     

基于改进的Mask R-CNN的染色体图像分割框架

针对染色体图像的人工分割耗时费力且当前自动分割方法精度不佳的问题,基于改进的Mask R-CNN提出了一种染色体图像分割框架——Mask Oriented R-CNN,引入方向信息对染色体图像进行实例分割。首先,新增有向包围框回归分支,以预测紧实包围框并获取方向信息;然后,提出新的交并比（IoU）度量——角度加权交并比（AwIoU）,从而结合方向信息与边的关系以改进冗余包围框的判据;最后,实现有向卷积通路结构,通过拷贝掩模分支通路并依据实例的方向信息选择训练路径来减少掩模预测中的干扰。实验结果表明,相较于基准模型Mask R-CNN,Mask Oriented R-CNN在IoU阈值为0.5时的平均精度均值指标提升了10.22个百分点,IoU阈值为0.5~0.95时的平均指标提升了4.91个百分点。研究结果显示,Mask Oriented R-CNN框架相较于基准模型取得了更好的染色体图像分割结果,有助于实现染色体图像自动分割。     

一种基于屏蔽码的ABAC静态策略冲突与冗余检测算法

针对基于属性的访问控制模型(Attribute-Based Access Control,ABAC)存在的静态策略冲突及冗余问题,提出了一种基于属性集有序化及二进制屏蔽码的静态策略冲突检测算法。该算法能够检测出全部的静态冲突,相对于目前典型的暴力算法与属性分割算法,降低了时间复杂度和空间复杂度;同时支持属性的新增及策略的新增或删除,能够更好地满足现代复杂网络环境的要求。     

Recognition and segmentation of teeth and mandibular nerve canals in panoramic dental X-rays by Mask RCNN

This study proposes a method based on the instance segmentation algorithm Mask RCNN for recognizing and segmenting 32 teeth and 2 mandibular nerve canals in panoramic dental X-rays. Compared with Faster RCNN, Mask RCNN has an additional semantic segmentation branch, which could directly obtain the position of teeth and the information about mandibular nerve canals in this study. At the same time, Mask RCNN introduces ROI Align, making Mask segmentation more accurate. A total of 120 training sets, 40 validation sets, and 120 test sets were used in the training and testing process. Forty of the test sets were used to test the full-tooth panoramic dental X-rays, and 40 were used for the edentulous panoramic dental X-rays, with 40 for the mandibular canals. The average precision, recall, and F1-score values of the full teeth were 96.59 %, 96.4 %, and 96.5 %, respectively. The P_m value of the defined edentulous panoramic dental X-rays was 95.41 %, and the average precision, recall, and F1-score values of mandibular canals were 76.05 %, 83.70 %, and 78.10 %, respectively. The results showed that the algorithm could effectively identify each tooth, including missing teeth and mandibular nerve canals in panoramic dental X-rays, solving the problem of too many oral structures in panoramic dental X-rays, which makes it difficult to determine the overall oral state. This study will help other researchers promote the research on artificial intelligence-assisted diagnosis in the oral field.     

子网掩码技术与应用

在计算机网络中,子网与子网掩码技术,是应用非常广泛的实用技术.从子网和子网掩码的概念、原理、方法和应用进行了系统研究,实践证明,用划分子网通用公式方法划分出来的子网和制定出来的子网掩码,是快速、准确和行之有效的,是值得推广和借鉴的.     

Si局域分子束外延技术

利用局域分子束外延技术生长了含有SiGe量子阱的岛状结构。实现了生长的岛状结构侧面不与掩模材料相接触。这种含有量子阱的岛状结构具有比相同结构量子阱强20多倍的光致发光强度。     

同步辐射光刻技术研究进展

光刻技术是推动集成电路制造业不断向前发展的关键技术。X射线光刻技术是下一代光刻技术的一种，具有产业化的应用前景。掩模技术是X射线光刻技术的难点，本文报告了国内利用同步辐射源的X射线掩模和光刻技术研究的最新进展。     

微直流伺服电机在光刻机中的应用研究

从实际应用出发,介绍了微直流伺服电机在光刻机中的选型分析。根据具体负载要求,确定所需电机相应的参数,从而得到能满足驱动需求的最优化的电机。     

Mask spoofing in face recognition and countermeasures

In this paper, initially, the impact of mask spoofing on face recognition is analyzed. For this purpose, one baseline technique is selected for both 2D and 3D face recognition. Next, novel countermeasures, which are based on the analysis of different shape, texture and reflectance characteristics of real faces and mask faces, are proposed to detect mask spoofing. In this paper, countermeasures are developed using both 2D data (texture images) and 3D data (3D scans) available in the mask database. The results show that each of the proposed countermeasures is successful in detecting mask spoofing, and the fusion of these countermeasures further improves the results compared to using a single countermeasure. Since there is no publicly available mask database, studies on mask spoofing are limited. This paper provides significant results by proposing novel countermeasures to protect face recognition systems against mask spoofing.