In the article, we present some refinements of three classes of transformation inequalities for zero-balanced hypergeometric functions by use of the updated monotonicity criterion for the quotient of power series.
A new high accuracy 6D ( Dimension ) wide range measuring technology and the method of coordinate transformations have been developed in a project for automobile body-in- white measurement in Michigan , U S A . The re...A new high accuracy 6D ( Dimension ) wide range measuring technology and the method of coordinate transformations have been developed in a project for automobile body-in- white measurement in Michigan , U S A . The requirements and the special features about the measured objective are mainly stated. The main instruments used in the project are introduced. The 6D measuring system , the method for coordinate transformations and the design of 3D optical target with hollow tetrahedron are described in detail . The 6D system and the technology can be certainly used in many other kinds of geometric mea- suring projects .展开更多
目的解决当前图像加密技术严重依赖混沌系统,使其通用性较差,难以直接加密非方形图像,且因混沌系统的周期性,算法的安全性不足的问题。方法提出了改进的引力模型耦合明文像素相关交叉算子的图像加密算法。首先,利用多个一维混沌映射,定...目的解决当前图像加密技术严重依赖混沌系统,使其通用性较差,难以直接加密非方形图像,且因混沌系统的周期性,算法的安全性不足的问题。方法提出了改进的引力模型耦合明文像素相关交叉算子的图像加密算法。首先,利用多个一维混沌映射,定义联合混沌变换模型,输出密钥流;随后,基于明文像素位置,设计像素相关交叉机制,联合密钥流,对明文进行高效置乱;构造质量动态变化函数,用其替代传统引力模型中的恒定粒子质量,增强算法的敏感性,并用改进的引力模型对置乱图像完成扩散,彻底改变像素值;最后,构建密文增强模型,对输出密文进行二次扩散,扩大密文的NPCR(Number of pixel change rate)与UACI(Unified average changed intensity)值。结果实验结果表明:与当前图像加密机制相比,所提加密算法不但可以扩散方形图像,而且能够对非方形目标直接加密,具有更高的通用性与安全性,以及更强的抗差分攻击能力。结论所提出的算法能够加密非方形尺寸的图像,具有较强的通用性与安全性。展开更多
基金supported by the Natural Science Foundation of China(61673169,11401191,11371125)the Tianyuan Special Funds of the Natural Science Foundation of China(11626101)the Natural Science Foundation of the Department of Education of Zhejiang Province(201635325)
文摘In the article, we present some refinements of three classes of transformation inequalities for zero-balanced hypergeometric functions by use of the updated monotonicity criterion for the quotient of power series.
文摘A new high accuracy 6D ( Dimension ) wide range measuring technology and the method of coordinate transformations have been developed in a project for automobile body-in- white measurement in Michigan , U S A . The requirements and the special features about the measured objective are mainly stated. The main instruments used in the project are introduced. The 6D measuring system , the method for coordinate transformations and the design of 3D optical target with hollow tetrahedron are described in detail . The 6D system and the technology can be certainly used in many other kinds of geometric mea- suring projects .
文摘目的解决当前图像加密技术严重依赖混沌系统,使其通用性较差,难以直接加密非方形图像,且因混沌系统的周期性,算法的安全性不足的问题。方法提出了改进的引力模型耦合明文像素相关交叉算子的图像加密算法。首先,利用多个一维混沌映射,定义联合混沌变换模型,输出密钥流;随后,基于明文像素位置,设计像素相关交叉机制,联合密钥流,对明文进行高效置乱;构造质量动态变化函数,用其替代传统引力模型中的恒定粒子质量,增强算法的敏感性,并用改进的引力模型对置乱图像完成扩散,彻底改变像素值;最后,构建密文增强模型,对输出密文进行二次扩散,扩大密文的NPCR(Number of pixel change rate)与UACI(Unified average changed intensity)值。结果实验结果表明:与当前图像加密机制相比,所提加密算法不但可以扩散方形图像,而且能够对非方形目标直接加密,具有更高的通用性与安全性,以及更强的抗差分攻击能力。结论所提出的算法能够加密非方形尺寸的图像,具有较强的通用性与安全性。
