The second approach is to use the concept of discrete logarithm . understanding this concept requires understanding some properties of multiplicative groups 第二种方法就是运用离散对数的概念。要掌握这些概念首先需要了解乘法群的概念。
The relationship of power or logarithm between them for crude oil was found and the average value of the power is about 0 . 55 通过对实验数据进行分析，石脑油的蒸发质量随时间表现出乘幂的变化关系，幂次大约为0 . 70 ；原油的蒸发质量随时间表现出乘幂或对数的变化关系，其幂次大约为0 . 55 。
This paper puts forward a new authentication scheme based on discrete logarithms , which has the characteristics of high security , simplicity and is easy to be carried out in distance education 本文提出了一种基于离散对数的身份认证方案，它有很好的安全性，并且认证过程简单，容易在远程教育中实现。
We can find a polynomial model of a time series in case its associated matrix is not diagonal and not of full rank by using the transformations of the exponential and the logarithm 对于不能对角和不满秩的时间序列矩阵，运用指数对数的可逆变换及相关的列变换化为满秩可对角的时间序列矩阵，从而找到代数多项式模型。
There is a linear relation of the logarithm between the pressure difference in round seepage flow region and the radius , for the same accuracy , it is better to select a center mesh grid that is a isometry system with inr interval 模型离散化时必须满足流量、体积守恒。圆形渗流区域内的压力差随半径是对数的线性关系，为保证相同计算精度，选择对lnr来说等距的中心网格系统。
For the image with random field feature , the description language is probability distribution model , and the description length equals the negative base - two logarithm of the probability of the image data ; for the region homogeneity properties of active contour , the description language is chosen as a sign gradient map , and the description length is the summation of sign gradient inside the active contour ; for the active contour regularity , the description language is smoothness , and the corresponding description length is the length of active contour curve 随机场图像的描述语言采用概率分布模型，描述长度是围道内外区域中图像数据概率的以2为底对数的负数；活动围道区域一致性的描述语言为有符号的梯度图，描述长度是围道内区域有符号梯度的总和；围道形态的描述语言采用平滑性，描述长度正比于围道的长度。
The primary advantage that elliptic curve systems have over systems based on the multiplicative group of a finite field ( and also over systems based on the intractability of integer factorization ) is the absence of a subexponential - time algorithm ( such as those of index calculus type ) that could find discrete logs in these groups 与基于有限域的乘法群系统(及基于整数分解的难解性之上的系统)相比,椭圆曲线系统的优势在于,迄今为止还没找到这类群上离散对数的次指数时间算法(如微积分类)
