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111.
提出利用四叉树自适应图像划分、源块池柔性分类并结合人类视觉特性的高速分形图像编码算法.与其它同类算法相比,该算法在编码速度、压缩比和图像质量等方面均有显著提高. 相似文献
112.
基于辐照度测量法和以人眼视觉对比度阈值为基准,研制了烟雾全遮蔽能力检测系统。该系统由数字照度计、旋转编码器、烟箱、步进电机、电磁离合器等部分组成,可以实现对TOP的全过程自动化测量。在温度为26℃,相对湿度为80%,光程调整范围为1~6m,光程调整精度为±2mm的条件下,对黄磷的TOP进行了检测,测试结果与经验值相比误差小于4%。 相似文献
113.
Constructions and Properties of k out of n Visual Secret Sharing Schemes 总被引:10,自引:0,他引:10
The idea of visual k out of n secret sharing schemes was introduced in Naor. Explicit constructions for k = 2 and k = n can be found there. For general k out of n schemes bounds have been described.Here, two general k out of n constructions are presented. Their parameters are related to those of maximum size arcs or MDS codes. Further, results on the structure of k out of n schemes, such as bounds on their parameters, are obtained. Finally, the notion of coloured visual secret sharing schemes is introduced and a general construction is given. 相似文献
114.
本文介绍了人眼视觉极限衬比测试仪的原理、设计方法、功能及主要参数.其主要原理是在主光路和辅助光路中分别置一偏振片,其偏振方向相互垂直.旋转组合光路中的检偏镜,即可得到可供观察用的变衬比鉴别率图象.文章指出,使用这种仪器检测人眼视觉衬比的良好结果表明,新仪器研制是成功的. 相似文献
115.
We employ in situ deposited secondary membranes of yeast (SMYs) to optimize permeate flux during microfiltration and ultrafiltration
of protein solutions. The deposited secondary membrane was periodically removed by backflushing, and a new cake layer was
deposited at the start of the next cycle. The effects of backflushing time, backflushing strength, wall shear rate, and amount
of secondary membrane deposited on the permeate flux were examined. Secondary membranes were found to increase the permeate
fluxin microfiltration by severalfold. Protein transmission was also enhanced owing to the presence of the secondary membrane,
and the amount of protein recovered was more than twice that obtained during filtration of protein-only solutions under othewise
identical conditions. In ultrafiltration, the flux enhancement owing to the secondary membrane was only 50% or less. In addition,
the flux for ultrafiltration was relatively insensitive to changes in the concentration of yeast used during deposition of
SMY and to the backflushing strength used to periodically remove the secondary membrane. 相似文献
116.
利用虚拟化学实验软件IrYdium Chemistry Lab为基本工具,探讨其在“盐类的水解”一节进行可视化教学设计的具体方法和教学应用价值。说明基于虚拟化学实验的可视化教学设计,能兼顾表达思维可视化过程和结果,有利于强化学生的学科理解能力。 相似文献
117.
118.
Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(7):837-850
An intuitive method is presented for detecting pseudosymmetries in Z′ > 1 cases as a complement to well‐proven strategies already available in the literature. It is based in the simple idea that the mid‐points between equivalent atoms in symmetrically related molecules are disposed according to simple well‐known patterns, which are easily recognizable by optical inspection. A number of Z′ = 4 cases in the literature are analyzed, which allows some of the potentialities of the method to be revealed. 相似文献
119.
A novel image fusion technique based on NSST (non-subsampled shearlet transform) is presented, aiming at resolving the fusion problem of spatially gray-scale visual light and infrared images. NSST, as a new member of MGA (multi-scale geometric analysis) tools, possesses not only flexible direction features and optimal shift-invariance, but much better fusion performance and lower computational costs compared with several current popular MGA tools such as NSCT (non-subsampled contourlet transform). We specifically propose new rules for the fusion of low and high frequency sub-band coefficients of source images in the second step of the NSST-based image fusion algorithm. First, the source images are decomposed into different scales and directions using NSST. Then, the model of region average energy (RAE) is proposed and adopted to fuse the low frequency sub-band coefficients of the gray-scale visual light and infrared images. Third, the model of local directional contrast (LDC) is given and utilized to fuse the corresponding high frequency sub-band coefficients. Finally, the final fused image is obtained by using inverse NSST to all fused sub-images. In order to verify the effectiveness of the proposed technique, several current popular ones are compared over three different publicly available image sets using four evaluation metrics, and the experimental results demonstrate that the proposed technique performs better in both subjective and objective qualities. 相似文献
120.